WO2018213671A1

WO2018213671A1 - Compositions including co-coagulated fluoropolymers and methods of using the same

Info

Publication number: WO2018213671A1
Application number: PCT/US2018/033336
Authority: WO
Inventors: Madhusudan CHARI; Kevin W. Anderson; Claude LAVALLÉE; Dale E. Hutchens; Shireen A. Mamun; Greta Dewitte
Original assignee: 3M Innovative Properties Company
Priority date: 2017-05-18
Filing date: 2018-05-18
Publication date: 2018-11-22

Abstract

A composition includes a co-coagulated mixture of a first branched, amorphous fluoropolymer and a second substantially linear, amorphous fluoropolymer. The co-coagulated mixture has a gel content of less than five percent by weight. The composition can further include at least one of a non-fluorinated, thermoplastic polymer as a major component of the composition or a polymer processing additive synergist. A method of reducing melt defects during the extrusion of a polymer is also provided. Use of a combination of the first and second amorphous fluoropolymers as a polymer processing additive is also provided.

Description

COMPOSITIONS INCLUDING CO-COAGULATED FLUOROPOLYMERS AND METHODS OF USING THE SAME

Cross-Reference to Related Application

This application claims priority to U.S. Provisional Application No. 62/508,204, filed May 18, 2017, the disclosure of which is incorporated by reference in its entirety herein. Background

Extrusion of polymeric materials in the formation and shaping of articles is a major segment of the plastic or polymeric articles industry. The quality of the extruded article and the overall success of the extrusion process are typically influenced by the interaction of the fluid material with the extrusion die. For any melt-processable thermoplastic polymer composition, there exists a critical shear rate above which the surface of the extrudate becomes rough or distorted and below which the extrudate will be smooth. See, for example, R. F. Westover, Melt Extrusion, Encyclopedia of Polymer Science and Technology, vol. 8, pp. 573-81 (John Wiley & Sons 1968). The desire for a smooth extrudate surface competes with, and must be optimized with respect to, the economic advantages of extruding a polymer composition at the fastest possible speed (for example at high shear rates).

At low shear rates, defects in extruded thermoplastics may take the form of "sharkskin", which is a loss of surface gloss that in more serious manifestations appears as ridges running more or less transverse to the extrusion direction. At higher rates, the extrudate can undergo

"continuous melt fracture" becoming grossly distorted. At rates lower than those at which continuous melt fracture is first observed, certain thermoplastics can also suffer from "cyclic melt fracture", in which the extrudate surface varies from smooth to rough.

There are other problems often encountered during the extrusion of thermoplastic polymers. They include a build-up of the polymer at the orifice of the die (known as die build up or die drool), high back pressure during extrusion runs, and excessive degradation or low melt strength of the polymer due to high extrusion temperatures. These problems slow the extrusion process either because the process must be stopped to clean the equipment or because the process must be run at a lower speed.

The addition of certain fluoropolymers can at least partially alleviate melt defects in extrudable thermoplastic polymers. Fluoropolymers that can be used as polymer processing additive include those described, for example, in U.S. Pat. Nos. 4,904,735 (Chapman, Jr.), 5,015,693 (Duchesne), 6,242,548 (Duchesne), 6,277,919 (Dillon), 6,599,982 (Oriani), 7,001,951 (Chapman, Jr.), and 7,375, 157 (Amos), U.S. Pat. App. Pub. No. 2010/311906 (Lavallee), and Int. App. Pub. No. WO 01/27197 (Blaedel). Summary

A co-coagulated mixture of amorphous fluoropolymers is effective, for example, as a polymer processing additive for reducing melt defects such as sharkskin in thermoplastic polymers. In some cases, the co-coagulated mixture of amorphous fluoropolymers is more effective in reducing melt defects than a comparative blend of amorphous fluoropolymers in which the amorphous fluoropolymers are the same except that the amorphous fluoropolymers are mixed after being separately coagulated, filtered, washed, and dried.

Fluoropolymers with long-chain branching can effectively reduce melt fracture during extrusion of host polymers and are typically more effective in this regard than fluoropolymers having similar Mooney viscosities and a linear chain topography. In some cases, as described herein, a co-coagulated mixture of a branched and a linear amorphous fluoropolymers has a time to clear melt fracture that unexpectedly is lower than that of the branched amorphous fluoropolymer on its own. Since in some cases a branched amorphous fluoropolymer can have a higher gel fraction than a linear amorphous fluoropolymer, the mixture of the first and second amorphous fluoropolymers described herein may have an additional benefit of being more easily dispersed in the extrudable polymer than a branched amorphous fluoropolymer.

In one aspect, the present disclosure provides a composition comprising a co-coagulated mixture of a first branched, amorphous fluoropolymer and a second substantially linear, amorphous fluoropolymer, wherein the co-coagulated mixture has a gel content of less than five percent by weight.

In another aspect, the present disclosure provides a composition including at least one of a non-fluorinated thermoplastic polymer as a major component of the composition or a polymer processing additive synergist. The composition further includes a co-coagulated mixture of a first branched, amorphous fluoropolymer and a second substantially linear, amorphous fluoropolymer. In some embodiments, the composition includes the non-fluorinated thermoplastic polymer. In some embodiments, the composition includes the polymer processing additive synergist. In some embodiments, the composition includes both the non-fluorinated thermoplastic polymer and the polymer processing additive synergist.

In another aspect, the present disclosure provides a method of reducing melt defects in a non-fluorinated thermoplastic polymer. The method includes combining the non-fluorinated, thermoplastic polymer and an amount of a co-coagulated mixture of a first branched, amorphous fluoropolymer and a second substantially linear, amorphous fluoropolymer to form an extrudable composition and extruding the extrudable composition.

In another aspect, the present disclosure provides the use of a co-coagulated mixture of amorphous fluoropolymers as a polymer processing additive. The co-coagulated mixture includes a first branched, amorphous fluoropolymer and a second substantially linear, amorphous fluoropolymer.

In some embodiments of the aforementioned aspects, the first branched, amorphous fluoropolymer has a long chain branching index of at least 0.2, and the second substantially linear, amorphous fluoropolymer has a long chain branching index of less than 0.2.

In this application:

Terms such as "a", "an" and "the" are not intended to refer to only a singular entity, but include the general class of which a specific example may be used for illustration. The terms "a", "an", and "the" are used interchangeably with the term "at least one".

The phrase "comprises at least one of followed by a list refers to comprising any one of the items in the list and any combination of two or more items in the list. The phrase "at least one of followed by a list refers to any one of the items in the list or any combination of two or more items in the list.

"Alkyl group" and the prefix "alk-" are inclusive of both straight chain and branched chain groups and of cyclic groups having up to 30 carbons (in some embodiments, up to 20, 15, 12, 10, 8, 7, 6, or 5 carbons) unless otherwise specified. Cyclic groups can be monocyclic or polycyclic and, in some embodiments, have from 3 to 10 ring carbon atoms.

The term "perfluoroalkyl group" includes linear, branched, and/or cyclic alkyl groups in which all C-H bonds are replaced by C-F bonds.

The phrase "interrupted by one or more -O- groups", for example, with regard to an alkyl, alkylene, or arylalkylene, refers to having part of the alkyl, alkylene, or arylalkylene on both sides of the one or more -O- groups. An example of an alkylene that is interrupted with one -O- group is -CH2-CH2-O-CH2-CH2-. Similarly, the phrase "terminated by one or more -O- groups", for example, with regard to an alkyl, alkylene, or arylalkylene, refers to having an -O- group on one end or the other of the alkyl, alkylene, or arylalkylene. An example of an alkylene that is terminated with an -O- group is -O-CH2-CH2-O-CH2-CH2-.

The term "aryl" as used herein includes carbocyclic aromatic rings or ring systems, for example, having 1, 2, or 3 rings, optionally containing at least one heteroatom (e.g., O, S, or N) in the ring, and optionally substituted by up to five substituents including one or more alkyl groups having up to 4 carbon atoms (e.g., methyl or ethyl), alkoxy having up to 4 carbon atoms, halo (i.e., fluoro, chloro, bromo or iodo), hydroxy, or nitro groups. Examples of aryl groups include phenyl, naphthyl, biphenyl, fluorenyl as well as furyl, thienyl, oxazolyl, and thiazolyl. "Arylalkylene" refers to an "alkylene" moiety to which an aryl group is attached. "Alkylarylene" refers to an "arylene" moiety to which an alkyl group is attached.

By 'synergist' is meant a compound that allows the use of a lower amount of the fluoropolymer as a polymer processing additive while achieving essentially the same improvement in extrusion and processing properties of the extrudable polymer as if a higher amount of the fluoropolymer polymer processing additive was used.

It should be understood that the term "polymer processing additive synergist" per se, as used herein, does not include a fluoropolymer or the non-fluorinated thermoplastic polymer. In other words, a polymer processing additive synergist per se does not include the polymer processing additive or the host polymer.

All numerical ranges are inclusive of their endpoints and nonintegral values between the endpoints unless otherwise stated (e.g., 1 to 5 includes 1, 1.5, 2, 2.75, 3, 3.80, 4, 5, etc.).

Various aspects and advantages of embodiments of the present disclosure have been summarized. The above Summary is not intended to describe each illustrated embodiment or every implementation of the present disclosure.

Detailed Description

Amorphous fluoropolymers useful for practicing the present disclosure typically do not exhibit a melting point. They typically have glass transitions temperatures below room temperature and exhibit little or no crystallinity at room temperature. Amorphous fluoropolymers useful as polymer processing additives include homopolymers and/or copolymers of fluorinated olefins. In some embodiments, the homopolymers or copolymers can have a fluorine atom-to- carbon atom ratio of at least 1:2, in some embodiments at least 1: 1; and/or a fluorine atom-to- hydrogen atom ratio of at least 1 : 1.5.

Amorphous fluoropolymers useful for practicing the present disclosure can comprise interpolymerized units derived from at least one partially fluorinated or perfluorinated ethylenically unsaturated monomer represented by formula

wherein each R^a is independently fluoro, chloro, bromo, hydrogen, a fluoroalkyl group (e.g. perfluoroalkyl having from 1 to 8, 1 to 4, or 1 to 3 carbon atoms, optionally interrupted by one or more oxygen atoms), a fluoroalkoxy group (e.g. perfluoroalkoxy having from 1 to 8, 1 to 4, or 1 to 3 carbon atoms, optionally interrupted by one or more oxygen atoms), alkyl or alkoxy of from 1 to 8 carbon atoms, aryl of from 1 to 8 carbon atoms, or cyclic saturated alkyl of from 1 to 10 carbon atoms. Examples of useful fluorinated monomers represented by formula include vinylidene fluoride (VDF), tetrafluoroethylene (TFE), hexafluoropropylene (HFP), chlorotrifluoroethylene, 2- chloropentafluoropropene, dichlorodifluoroethylene, 1,1-dichlorofluoroethylene, 1- hydropentafluoropropylene, 2-hydropentafluoropropylene, 3,3,3-trifluoropropene, perfluorinated vinyl ethers, perfluorinated allyl ethers, and mixtures thereof.

In some embodiments, at least one of the first or second amorphous fluoropolymers includes units from one or more monomers independently represented by formula CF₂=CFORf, wherein Rf is perfluoroalkyl having from 1 to 8, 1 to 4, or 1 to 3 carbon atoms, optionally interrupted by one or more -O- groups. Perfluoroalkoxyalkyl vinyl ethers suitable for making an amorphous fluoropolymer include those represented by formula

in which each n is independently from 1 to 6, z is 1 or 2, and Rf₂ is a linear or branched perfluoroalkyl group having from 1 to 8 carbon atoms and optionally interrupted by one or more -O- groups. In some embodiments, n is from 1 to 4, or from 1 to 3, or from 2 to 3, or from 2 to 4. In some embodiments, n is 1 or 3. In some embodiments, n is 3. C_nF_2n may be linear or branched. In some embodiments, C_nF_2n can be written as (CF₂)_n, which refers to a linear perfluoroalkylene group. In some embodiments, C_nF_2n is -CF₂-CF₂-CF₂-. In some embodiments, C_nF_2n is branched, for example, -CF₂-CF(CF₃)-. In some embodiments, (OC_nF_2n)z is represented by

-0-(CF₂) i-4-[0(CF₂)i-4]o-i . In some embodiments, Rf₂ is a linear or branched perfluoroalkyl group having from 1 to 8 (or 1 to 6) carbon atoms that is optionally interrupted by up to 4, 3, or 2 -O- groups. In some embodiments, Rf₂ is a perfluoroalkyl group having from 1 to 4 carbon atoms optionally interrupted by one -O- group. Suitable monomers represented by formula CF₂=CFORf and CF₂=CF(OC_nF_2n)_zORf₂ include perfluoromethyl vinyl ether, perfluoroethyl vinyl ether, perfluoropropyl vinyl ether, CF₂=CFOCF₂OCF₃, CF₂=CFOCF₂OCF₂CF₃, CF₂=CFOCF₂CF₂OCF₃, CF₂=CFOCF₂CF₂CF₂OCF₃, CF₂=CFOCF₂CF₂CF₂CF₂OCF₃, CF₂=CFOCF₂CF₂OCF₂CF₃, CF₂=CFOCF₂CF₂CF₂OCF₂CF₃, CF₂=CFOCF₂CF₂CF₂CF₂OCF₂CF₃, CF₂=CFOCF₂CF₂OCF₂OCF₃, CF₂=CFOCF₂CF₂OCF₂CF₂OCF₃, CF₂=CFOCF₂CF₂OCF₂CF₂CF₂OCF₃,

CF₂=CFOCF₂CF₂OCF₂CF₂CF₂CF₂OCF₃, CF₂=CFOCF₂CF₂OCF₂CF₂CF₂CF₂CF₂OCF₃,

CF₂=CFOCF₂CF₂(OCF₂)₃OCF₃, CF₂=CFOCF₂CF₂(OCF₂)₄OCF₃,

CF₂=CFOCF₂CF₂OCF₂OCF₂OCF₃, CF₂=CFOCF₂CF₂OCF₂CF₂CF₃

CF₂=CFOCF₂CF₂OCF₂CF₂OCF₂CF₂CF₃, CF₂=CFOCF₂CF(CF₃)-0-C₃F₇ (PPVE-2),

CF₂=CF(OCF₂CF(CF₃))₂-0-C₃F₇ (PPVE-3), and CF₂= CF(OCF₂CF(CF₃))₃-0-C₃F₇ (PPVE-4). Many of these perfluoroalkoxyalkyl vinyl ethers can be prepared according to the methods described in U.S. Pat. Nos. 6,255,536 (Worm et al.) and 6,294,627 (Worm et al.).

Perfluoroalkyl alkene ethers and perfluoroalkoxyalkyl alkene ethers may also be useful for making an amorphous polymer for the composition, method, and use according to the present disclosure. In addition, the amorphous fluoropolymers may include interpolymerized units of fluoro (alkene ether) monomers, including those described in U.S. Pat. Nos. 5,891,965 (Worm et al.) and 6,255,535 (Schulz et al.). Such monomers include those represented by formula

CF₂=CF(CF₂)_m-0-Rf, wherein m is an integer from 1 to 4, and wherein Rf is a linear or branched perfluoroalkylene group that may include oxygen atoms thereby forming additional ether linkages, and wherein Rf contains from 1 to 20, in some embodiments from 1 to 10, carbon atoms in the backbone, and wherein Rf also may contain additional terminal unsaturation sites. In some embodiments, m is 1. Examples of suitable fluoro (alkene ether) monomers include perfluorinated ethers such as CF₂=CFCF₂-0-CF₃, CF₂=CFCF₂-0-CF₂-0-CF₃, CF₂=CFCF₂-0-CF₂CF₂-0-CF₃, CF₂=CFCF₂-0-CF₂CF₂-0-CF₂-0-CF₂CF₃, CF₂=CFCF₂-0-CF₂CF₂-0-CF₂CF₂CF₂-0-CF₃, CF₂=CFCF₂-0-CF₂CF₂-0-CF₂CF₂-0-CF₂-0-CF₃, CF₂=CFCF₂CF₂-0-CF₂CF₂CF₃. Suitable perfluoroalkoxyalkyl allyl ethers include those represented by formula

in which n, z, and Rf₂ are as defined above in any of the embodiments of perfluoroalkoxyalkyl vinyl ethers. Examples of suitable perfluoroalkoxyalkyl allyl ethers include

CF₂=CFCF₂OCF₂CF₂OCF₃, CF₂=CFCF₂OCF₂CF₂CF₂OCF₃, CF₂=CFCF₂OCF₂OCF_3,

CF₂=CFCF₂OCF₂OCF₂CF₃, CF₂=CFCF₂OCF₂CF₂CF₂CF₂OCF₃, CF₂=CFCF₂OCF₂CF₂OCF₂CF₃, CF₂=CFCF₂OCF₂CF₂CF₂OCF₂CF₃, CF₂=CFCF₂OCF₂CF₂CF₂CF₂OCF₂CF₃,

CF₂=CFCF₂OCF₂CF₂OCF₂OCF₃, CF₂=CFCF₂OCF₂CF₂OCF₂CF₂OCF₃,

CF₂=CFCF₂OCF₂CF₂OCF₂CF₂CF₂OCF₃, CF₂=CFCF₂OCF₂CF₂OCF₂CF₂CF₂CF₂OCF₃,

CF₂=CFCF₂OCF₂CF₂OCF₂CF₂CF₂CF₂CF₂OCF₃, CF₂=CFCF₂OCF₂CF₂(OCF₂)₃OCF₃,

CF₂=CFCF₂OCF₂CF₂(OCF₂)₄OCF₃, CF₂=CFCF₂OCF₂CF₂OCF₂OCF₂OCF₃,

CF₂=CFCF₂OCF₂CF₂OCF₂CF₂CF₃, CF₂=CFCF₂OCF₂CF₂OCF₂CF₂OCF₂CF₂CF₃,

CF₂=CFCF₂OCF₂CF(CF₃)-0-C₃F₇, and CF₂=CFCF₂(OCF₂CF(CF₃))₂-0-C₃F₇. Many of these perfluoroalkoxyalkyl allyl ethers can be prepared, for example, according to the methods described in U.S. Pat. No. 4,349,650 (Krespan).

At least one of the first or second amorphous fluoropolymers may also comprise interpolymerized units derived from the interpolymerization of at least one monomer R^aCF=CR^a ₂ with at least one non-fluorinated, copolymerizable comonomer represented by formula R^b ₂C=CR^b ₂, wherein each R^b is independently hydrogen, chloro, alkyl having from 1 to 8, 1 to 4, or 1 to 3 carbon atoms, a cyclic saturated alkyl group having from 1 to 10, 1 to 8, or 1 to 4 carbon atoms, or an aryl group of from 5 to 8 carbon atoms. Examples of useful monomers represented by formula R^b ₂C=CR^b ₂ include ethylene and propylene.

Perfluoro-l,3-dioxoles may also be useful to prepare the amorphous fluoropolymer disclosed herein. Perfluoro-l,3-dioxole monomers and their copolymers are described in U. S. Pat. No. 4,558, 141 (Squires).

Examples of useful amorphous copolymers of fluorinated olefins are those derived, for example, from vinylidene fluoride and one or more additional olefins, which may or may not be fluorinated (e.g., represented by formula

In some embodiments, useful fluoropolymers include copolymers of vinylidene fluoride with at least one terminally unsaturated fluoromonoolefin represented by formula

containing at least one fluorine atom on each double-bonded carbon atom. Examples of comonomers that can be useful with vinylidene fluoride include hexafluoropropylene, chlorotrifluoroethylene, 1- hydropentafluoropropylene, 3,3,3-trifluoropropene, and 2-hydropentafluoropropylene. Other examples of amorphous fluoropolymers useful for practicing the present disclosure include copolymers of vinylidene fluoride, tetrafluoroethylene, and hexafluoropropylene or 1- or 2- hydropentafluoropropylene and copolymers of tetrafluoroethylene, propylene, and, optionally, vinylidene fluoride. In some embodiments, at least one of the first or second amorphous fluoropolymer is a copolymer of hexafluoropropylene and vinylidene fluoride. Such

fluoropolymers are described in U.S. Pat. Nos. 3,051,677 (Rexford) and 3,318,854 (Honn, et al.) for example. In some embodiments, at least one of the first or second amorphous fluoropolymer is a copolymer of perfluoropropylene, vinylidene fluoride and tetrafluoroethylene. Such fluoropolymers are described in U.S. Pat. No. 2,968,649 (Pailthorp et al.), for example.

Amorphous fluoropolymers including interpolymerized units of VDF and HFP typically have from 30 to 90 percent by weight VDF units and 70 to 10 percent by weight HFP units. Amorphous fluoropolymers including interpolymerized units of TFE and propylene typically have from about 50 to 80 percent by weight TFE units and from 50 to 20 percent by weight propylene units. Amorphous fluoropolymers including interpolymerized units of TFE, VDF, and propylene typically have from about 45 to 80 percent by weight TFE units, 5 to 40 percent by weight VDF units, and from 10 to 25 percent by weight propylene units. Those skilled in the art are capable of selecting specific interpolymerized units at appropriate amounts to form an amorphous fluoropolymer. In some embodiments, polymerized units derived from non-fluorinated olefin monomers are present in the amorphous fluoropolymer at up to 25 mole percent of the fluoropolymer, in some embodiments up to 10 mole percent or up to 3 mole percent. In some embodiments, polymerized units derived from at least one of perfluoroalkyl vinyl ether or perfluoroalkoxyalkyl vinyl ether monomers are present in the amorphous fluoropolymer at up to 50 mole percent of the fluoropolymer, in some embodiments up to 30 mole percent or up to 10 mole percent.

In some embodiments, at least one of the first or second amorphous fluoropolymers useful for practicing the present disclosure is a TFE/propylene copolymer, a TFE/propylene/VDF copolymer, a VDF/HFP copolymer, a TFE/VDF/HFP copolymer, a TFE/perfluoromethyl vinyl ether (PMVE) copolymer, a TFE/CF₂=CFOC₃F₇ copolymer, a TFE/CF₂=CFOCF3/CF2=CFOC₃F7 copolymer, a

copolymer, a TFE/ethyl vinyl ether (EVE) copolymer, a TFE/butyl vinyl ether (BVE) copolymer, a TFE/EVE/BVE copolymer, a VDF/CF₂=CFOC₃F₇ copolymer, an ethylene/HFP copolymer, a TFE/ HFP copolymer, a CTFE/VDF copolymer, a TFE/VDF copolymer, a TFE/VDF/PMVE/ethylene copolymer, or a

TFE/VDF/CF₂=CFO(CF₂)30CF₃ copolymer.

The composition, method, and use according to the present disclosure includes a combination of a first branched, amorphous fluoropolymer a second substantially linear, amorphous fluoropolymer. Compositions, methods, and uses according to the present disclosure may include three or more co-coagulated amorphous fluoropolymers, with at least one being branched and at least one being substantially linear. Fluoropolymers that include long-chain branching can be prepared by using modifiers such as bisolefins or halogen containing monoolefins during the polymerization reaction. See, for example, U.S. Pat. Appl. Pub. No. 2010/0311906 (Lavallee et al.) and U.S. Pat. No. 7,375,157 (Amos et al.).

In some embodiments, the first branched fluoropolymer can be prepared by including one or more olefins during the polymerization reaction that has a bromine or iodine atom on at least one carbon of the double bond. The olefin may be non-fluorinated (that is, not contain fluorine atoms) or partially fluorinated (that is, some but not all hydrogen atoms have been replaced with fluorine atoms), or the olefin may be a perfluorinated compound in which all hydrogen atoms have been replaced with fluorine atoms except for those replaced with bromine or iodine.

Useful olefins having a bromine or iodine atom on at least one carbon of the double bond may be represented by formula X₂C=CXZ. In this formula, each X is independently selected from hydrogen, fluorine, bromine, chlorine or iodine, with the proviso that at least one X is bromine or iodine, and Z represents hydrogen, fluorine, bromine, chlorine or iodine, a perfluoroalkyl group, a perfluoroalkoxy group, or a perfluoropolyether group. Examples of perfluoroalkyl groups include linear or branched perfluoroalkyl groups having from 1 and 8 carbon atoms or 1 to 5 carbon atoms. Examples of perfluoroalkoxy groups include those that have from 1 and 8 carbon atoms, or from 1 and 5 carbon atoms, wherein the alkyl group may be linear or branched. The perfluoroalkoxy group may be a perfluoropolyether group, such as which may be represented by formula

-0(R¹fO)_n(R² O)_mR³f, wherein R and R² _f are each linear or branched perfluoroalkylene groups having 1 to 6 carbon atoms, or 2 to 6 carbon atoms; m and n are independently 0 to 10 with m+n being at least 1; and R^f is a perfluoroalkyl group having 1 to 6 carbon atoms. Mixtures of olefins represented by formula X₂C=CXZ may also be useful.

In some embodiments, useful olefins represented by formula X₂C=CXZ include those wherein X is hydrogen, fluorine, or bromine with the proviso that at least one X represents bromine, and Z is hydrogen, fluorine, bromine, a perfluoroalkyl group, or a perfluoroalkoxy group. Specific examples of these olefins include l-bromo-l,2,2,-trifluoroethylene, bromotrifluoroethylene (referred as BTFE), vinylbromide, 1,1-dibromoethylene, 1,2- dibromoethylene, l-bromo-2,3,3,3-tetrafluoro-propene, and l-bromo-2,2-difluoroethylene (BDFE). In some embodiments, useful olefins represented by formula X₂C=CXZ include iodo(perfluoroalkyl)ethylene. An example of a suitable iodo(perfluoroalkyl)ethylene is 4-iodo- 3,3,4,4-tetrafluorobutene-l (ITFB).

In some embodiments, the first branched fluoropolymer can be prepared by including one or more olefins during the polymerization reaction represented by formula X^a2C=CX^a-Rp-Br or

X^a2C=CX^a-Rp-I. In this formula each X^a is independently hydrogen, fluorine, bromine, chlorine or iodine; Rp is a perfluoroalkylene group, typically having 1 to 8 carbon atoms, a

perfluorooxyalkylene group or a divalent perfluoropolyether group. The bromine may be contained in a terminal position (that is, on a primary carbon atom) of the Rp group, but may alternatively be contained along the chain of the Rp group (that is, on a secondary or tertiary carbon atom). Examples of olefins represented by formula X^a2C=CX^a-Rp-Br or

X ₂C=CX^a-Rp-I include CH₂=CH-(CF2)o-5-CF₂Br, CH₂=CH-(CF2)o-5-CF₂I,

CF₂=CF-(CF2)o-5-CFBr-CF₃, CF2=CF-(CF2)o-5-CF2Br,

CH₂=CH-0-(CF2)o-5-CF₂Br, CF₂=CF-0-(CF2)o-5-CF₂Br,

CF2=CF-(0-CF2-CF2-0)o_3-(CF2)o-5-CF₂Br,

CF2=CF-0-(CF2-CF(CF3)-0-)o-3-(CF2)o-5-CF₂Br, CF2=CH-0-(CF₂)o-5-CF₂Br, and

CH₂=CF-0-(CF2)o-5-CF₂Br.

In some embodiments, the first branched fluoropolymer can be prepared by including one or more olefins during the polymerization reaction represented by the formula

CH2=CH-R 3-CH=CH2, wherein R 3 is a divalent perfluoroaliphatic group optionally containing one or more O atoms, a perfluoroarylene group, and a perfluoroalkarylene group. The divalent perfluoroaliphatic group includes, for instance, perfluoroalkylene groups and perfluorooxyalkylene groups. Examples of suitable olefins represented by formula CH2=CH-R 3-CH=CH2 include

1,8-divinyl perfluoro(octane), 1,6-divinyl perfluoro(hexane), and 1,4-divinyl perfluoro(butane).

Ri R2C=C(R₃)-W-C(R₄)=CR₅R₆, wherein Ri , R₂, R3, R4, R5, and R₆ are each independently hydrogen, fluorine, an alkyl group having from 1 to 5 carbon atoms, or fluorinated alkyl group having from 1 to 5 carbon atoms; W is an alkylene or cycloalkylene group having from 1 to 18 carbon atoms, which may be linear or branched and which is optionally at least one of interrupted or terminated by oxygen atoms, and which may also be partially fluorinated or perfluorinated. When a W group is terminated by an oxygen atom or oxygen atoms, the olefin represented by formula Ri R2C=C(R3)-W-C(R4)=CR5R6 is a vinyl ether or divinyl ether. When a W group is interrupted by an oxygen atom or oxygen atoms, the olefin represented by formula

^R1^R2^C=C(^R3)-^W_C(^R4)^=CR5^R6 ^{can be an all}y! ^{ether or} diallyl ether. W can also be arylene which may be fluorinated or non-fluorinated having from 5 to 14, 5 to 12, or 5 to 10 carbon atoms and which may be unsubstituted or substituted with one or more halogens other than fluoro, perfluoroalkyl (e.g. -CF₃ and -CF₂CF₃), perfluoroalkoxy (e.g. -0-CF₃, -OCF₂CF₃),

perfluoropolyoxyalkyl (e.g., -OCF₂OCF₃; -CF₂OCF₂OCF₃), fluorinated, perfluorinated, or non- fluorinated phenyl or phenoxy, which may be substituted with one or more perfluoroalkyl, perfluoroalkoxy, perfluoropolyoxyalkyl groups, one or more halogens other than fluoro, or combinations thereof. In some embodiments, W is a perfluoroalkylene group having 4 to 12 carbon atoms, 6 to 12 carbon atoms, 8 to 12 carbon atoms, 4 to 6 carbon atoms, or 4 to 8 carbon atoms. In some embodiments, W is a perfluoropolyoxyalkylene group, represented by formula

-(Q)p-CF20-(CF2CF20)q(CF20)_r-CF2-(Q) -, wherein each Q is independently an alkylene or oxyalkylene group having 1 to 10 carbon atoms, each p is independently 0 or 1, q and r are integers such that the m/n ratio is from 0.2 to 5 and the molecular weight of the

perfluoropolyoxyalkylene group is from 500 to 10,000, or from 1,000 to 4,000. In some embodiments, Q is -CH₂OCH₂- or -CH20(CH₂CH₂0)_SCH2-, wherein s is from 1 to 3.

Ri R2C=C(R3)-W-C(R4)=CR5R6 that are more specifically represented by formula

CY₂=CX^b-(CF₂)_a-(0-CF(Z^a)-CF₂)_b-0-(CF₂)_c-(0-CF(Z^a)-CF₂)_d-(0)e-(CF(A))f-CX^b=CY₂, wherein a is 0, 1, or 2; b is 0, 1, or 2; c is 0, 1, 2, 3, 4, 5, 6, 7, or 8; d is 0, 1, or 2; e is 0 or 1; f is 0, 1, 2, 3, 4, 5, or 6; Z^a is independently F or CF₃; A is F or a perfluorinated alkyl group; each X^b is independently H or F; and each Y is independently H, F, or CF₃. In some embodiments, X^b is F, and each Y is independently F or CF₃. In these embodiments of formula

Ri R2C=C(R3)-W-C(R4)=CR5R6, W is perfluoroalkyl group that is at least one of interrupted or terminated by at least one oxygen atom. Examples of useful fluorinated bisolefin compounds include CF₂=CF-0-(CF₂)₂-0-CF=CF₂, CF₂=CF-0-(CF₂)₃-0-CF=CF₂,

CF₂=CF-0-(CF₂)₄-0-CF=CF₂, CF₂=CF-0-(CF₂)₅-0-CF=CF₂, CF₂=CF-0-(CF₂)₆-0-CF=CF₂, CF₂=CF-CF₂-0-(CF₂)₂-0-CF=CF₂, CF₂=CF-CF₂-0-(CF₂)₃-0-CF=CF₂,

CF₂=CF-CF₂-0-(CF₂)₄-0-CF=CF₂, CF₂=CF-CF₂-0-(CF₂)₅-0-CF=CF₂, CF₂=CF- CF₂-0-(CF₂)₆-0-CF=CF₂, CF₂=CF-CF₂-0-(CF₂)₂-0-CF₂-CF=CF₂, CF₂=CF-CF₂-0-(CF₂)₃-0-CF₂-CF=CF₂, CF₂=CF-CF₂-0-(CF₂)₄-0-CF₂-CF=CF₂,

CF₂=CF-CF₂-0-(CF₂)₅-0-CF₂-CF=CF₂, CF₂=CF-CF₂-0-(CF₂)₆-0-CF₂-CF=CF₂,

CF₂=CF-0-CF₂CF₂-CH=CH₂, CF₂=CF-(OCF(CF₃)CF₂)-0-CF₂CF₂-CH=CH₂,

CF₂=CF-(OCF(CF₃)CF₂)₂-0-CF₂CF₂-CH=CH₂, CF₂=CF CF₂-0-CF₂CF₂-CH=CH₂,

CF₂=CFCF₂-(OCF(CF₃)CF₂)-0-CF₂CF₂-CH=CH₂,

CF₂=CFCF₂-(OCF(CF₃)CF₂)₂-0-CF₂CF₂-CH=CH₂, CF₂=CF-CF₂-CH=CH₂,

CF₂=CF-0-(CF₂)_2-6-0-CF₂-CF₂-CH=CH₂, CF₂=CFCF₂-0-(CF₂)_2-6-0-CF₂-CF₂-CH=CH₂, CF₂=CF-(OCF(CF₃)CF₂)o-₂-0-CF(CF₃)-CH=CH₂,

CF₂=CF-CF₂-(OCF(CF₃)CF₂)o-₂-0-CF(CF₃)-CH=CH₂,

CF₂=CF-(CF₂)o-i-(0-CF(CF₃)CF₂)o-₂-0-(CF₂)i_-6-(OCF(CF₃)CF₂)o-₂-0-CF=CF₂. In some embodiments, the fluorinated bisolefin compound is CF₂=CF-0-(CF₂)_c-0-CF=CF₂ where c is an integer from 2-6; CF₂=CF-(CF₂)_a-0-(CF₂)_c-0-(CF₂)f-CF=CF₂ where c is an integer from 2-6 and a and f are independently 0 or 1; or a perfluorinated compound comprising a perfluorinated vinyl ether and a perfluorinated allyl ether.

The bisolefin modifiers may be prepared using a variety of methods, for example, those described in U.S. Pat. Nos. 4,273,728 (Krespan), 3,326,984 (Anderson et al.), and 6,300,526 (Navarrini et al). Some are commercially available from Anles, St. Petersburg, Russia.

Mixtures of olefin modifiers represented by formulas X₂C=CXZ, X^a2C=CX^a-Rp-Br,

CH2=CH-Rf3-CH=CH₂, Ri R2C=C(R₃)-W-C(R₄)=CR₅R₆, and

CY₂=CX^b-(CF₂)a-(0-CF(Z^a)-CF₂)b-0-(CF₂)_c-(0-CF(Z^a)-CF₂)_d-(0)e-(CF(A))f-CX^b=CY₂ as described above in any of their embodiments may be useful for preparing the first branched, amorphous fluoropolymer. The olefin modifiers should generally be used at fairly low levels to avoid too extensive branching to occur during the polymerization. The amount of olefin modifier that is typically used in the polymerization to cause a desired amount of branching of the fluoropolymer depends on the nature of the modifier used and on the polymerization conditions (e.g., reaction time and temperature). The amount of modifier to be used is generally not more than 1 % by weight and, in some embodiments, not more than 0.7% or 0.5% by weight based on the total weight of monomers used in the polymerization. A useful amount may be from about 0.

01 % to 1 % by weight, conveniently from about 0.02 to 0.5 % by weight, alternatively about 0.01 to 0.3 % by weight, or from about 0.05 % to 0.25 % by weight. The modifier can be added at the start of the polymerization and/or may be added during the polymerization in a continuous way and/or portion-wise. In some embodiments, the co-coagulated mixture of the first branched, amorphous fluoropolymer and the second substantially linear, amorphous fluoropolymer has a gel content of less than five percent. In some embodiments, the co-coagulated mixture has a gel content of less than 4, 3, 2, 1, 0.5, 0.25, or 0.1 percent. The co-coagulated mixture may also have no gel content as determined by the method described below. Gel content can be controlled, for example, by selecting the level of any of the olefin modifiers represented by formulas

X^a ₂C=CX^a-R_F-Br, CH2=CH-Rf3-CH=CH₂, Ri R2C=C(R₃)-W-C(R₄)=CR₅R₆, and

CY2=CX^b-(CF2)a-(0-CF(Z^a)-CF2)b-0-(CF2)_c-(0-CF(Z^a)-CF₂)d-(0)e-(CF(A))f-CX^b=CY2 as described above in any of their embodiments to be at any of the levels described above to make the first amorphous fluoropolymer. The first amorphous fluoropolymer itself may have a gel content of less than 25, 20, 15, 10, 5, 4, 3, 2, 1, 0.5, 0.25, or 0.1 percent by weight. The first amorphous fluoropolymer itself may also have no gel content as determined by the method described below. The second amorphous fluoropolymer itself, being substantially linear, typically has no gel content as determined by the method described below.

The gel content is determined as described in U.S. Pat. No. 4,115,481 (Finlay et al.). A solution-dispersion of a known concentration (about 1% polymer) in 2-butanone is filtered through a paper filter and evaporation of the filtrate to dryness to determine the concentration of soluble polymer. The amount of gel polymer is calculated from the difference in concentration of total polymer and concentration of polymer in the soluble portion. In some cases, gel content of a 2- butanone solution-dispersion can also be determined by placing it in a closed centrifuge tube and centrifuging at about 17000 rpm for 30 minutes. The concentration of polymer in the supernatant liquid is determined by evaporation of dryness of a known volume.

The first amorphous fluoropolymer useful for practicing the present disclosure is branched. That is, the polymer is not linear, in that one or more branches from the backbone are present. The first amorphous fluoropolymer can also be said to have long chain branches. Without intending to be bound by theory, it is believed that these branches can result from abstraction of the bromine or iodine atom from an olefin modifier including bromide or iodine as described above in any of its embodiments once it is polymerized into the backbone of the fluoropolymer. The so-produced radical on the backbone may then cause further polymerization with the result that a polymeric chain is formed as a branch on the backbone. Similarly, bis-olefins can cause long chain branches as a result of having two polymerizable groups in the molecule. Such branches are known in the art as long chain branches or LCBs.

The level of branching or non-linearity of the first amorphous fluoropolymers can be characterized through the long chain branching index (LCBI). The LCBI can be determined as described in R. N. Shroff, H. Mavridis; Macromol., 32, 8464-8464 (1999) & 34, 7362-7367 (2001) according to the equation:

n^Va 1

In the above equation,

is the zero shear viscosity (units Pa*s) of the branched fluoropolymer measured at a temperature T, [η] is the intrinsic viscosity (units mL/g) of the branched fluoropolymer at a temperature T' in a solvent in which the branched fluoropolymer can be dissolved, and a and k are constants. These constants are determined from the following equation:

¾,„=^[ eq. 2

wherein η₀,ι,_η and [η]ι,„ represent respectively the zero shear viscosity and intrinsic viscosity of the corresponding linear fluoropolymer measured at the respective same temperatures T and T' and in the same solvent. Thus, the LCBI is independent of the selection of the measurement temperatures and solvent chosen, provided, of course, that the same solvent and temperatures are used in equations 1 and 2. The LCBI of the first branched, amorphous fluoropolymer may, for instance, have a value of at least about 0.2. The LCBI of the first branched, amorphous fluoropolymer may be at least about 0.2, at least about 0.3, or even at least about 0.4. The LCBI of the first branched, amorphous fluoropolymer may be less than about 5, less than about 2.0 or less than about 1.0. Generally, the LCBI may be from about 0.2 up to about 5 or from about 0.2 to about 2.0.

On the other hand, the second substantially linear, amorphous fluoropolymer typically has a long-chain branch index of less than 0.2, in some embodiments less than 0.19, 0.15, 0.1, or less than 0.05. Typically, second substantially linear, amorphous fluoropolymers are made in the absence of olefin modifiers represented by formulas X₂C=CXZ, X^a2C=CX^a-Rp-Br,

CH2=CH-Rf3-CH=CH₂, Ri R₂C=C(R3)-W-C(R4)=CR₅R₆, and

CY2=CX^b-(CF2)a-(0-CF(Z^a)-CF2)_b-0-(CF2)_c-(0-CF(Z^a)-CF2)_d-(0)e-(CF(A))f-CX^b=CY₂ as described above in any of their embodiments or with amounts of these modifiers less than 0.01%, less than 0.005%, or less than 0.001% by weight based on the total weight of monomers used in the polymerization.

An alternative method for determining the presence of long chain branches relies on the calculation of critical relaxation coefficients. This method is particularly suitable for insoluble polymers. As disclosed by Wood-Adams et al. (Macromolecules 2000, 33, No.20, 7489-7499), when plotting the phase angle δ versus the log of the measurement frequency ω, polymers having long chain branches exhibit a plateau or additional curvature in the function of 5(log ω) while linear polymers do not. When the polymer is linear the resulting plot only has a single curvature (compare Stange et a\., Macromolecules 2007, 40, 2409-2416, figure 6 where the phase angle was plotted versus the log of the shear modulus instead of the angular frequency (ω) but a similar curve is obtained when plotting the phase angle (δ) versus the log of the angular frequency (ω)). The critical relaxation exponent n can be obtained by dividing the phase angle at gel point (8_C) by 90°, i.e. n = 8_C /90°. The phase angle at gel point (8_C) is the angle at which, in case of long chain branches being present, the 8(log co)-function plateaus or forms a second curvature, i.e. where the first derivative of the plot has its maximum and/or where the 2nd derivative passes zero.

According to Garcia-Franco et al. (Macromolecules 2001, 34, No.10, 3115-3117), the plateau in the aforementioned 8(log co)-function will shift to lower phase angles δ when the amount of LCBs in the polymer increases. The closer n is to 1, the fewer long chain branches are present. The critical relaxation exponent n for the first branched, amorphous fluoropolymers disclosed herein typically is less than 1 and more than 0. Generally, n will be between 0.3 and 0.92, preferably between 0.35 and 0.85.

In some embodiments of the composition, method, and use according to the present disclosure, at least one of the first branched, amorphous fluoropolymer or the second substantially linear, amorphous fluoropolymer has a Mooney viscosity ML l+10 @ 121°C in a range from 30 to 150. In some embodiments of the composition, method, and use according to the present disclosure, at least one of the first branched, amorphous fluoropolymer or the second substantially linear, amorphous fluoropolymer has a Mooney viscosity ML l+10 @ 121°C in a range from 30 to 120, 30 to 110, 40 to 100, 30 to 90, 40 to 90, 30 to 60, 30 to 40, about 60 to about 90, about 60 to about 80, about 90 to about 100, or about 65 to about 75. Mooney viscosities can be controlled, for example, by controlling molecular weight and branching in the fluoropolymer. Mooney viscosity is determined using ASTM D 1646-06 Part A by a MV 2000 instrument (available from Alpha Technologies, Ohio, USA) using a large rotor (ML 1+10) at 121 °C. Mooney viscosities specified above are in Mooney units. In any of these embodiments, the difference between the Mooney viscosity ML 1+10 @ 121°C of the first branched, amorphous fluoropolymer and the Mooney viscosity ML 1+10 @ 121°C of the second substantially linear, amorphous fluoropolymer can be up to 20, in some embodiments, less than 20 or up to 15 or up to 10.

In some embodiments, the difference between the Mooney viscosity ML 1+10 @ 121°C of the first branched, amorphous fluoropolymer and the Mooney viscosity ML 1+10 @ 121°C of the second substantially linear, amorphous fluoropolymer is greater than 20, in some embodiments, greater than 30, 40, or 50. In some embodiments, the difference between the Mooney viscosities ML 1+10 @ 121°C of the first and second amorphous fluoropolymers is up to 120, in some embodiments, up to 100, 90, 80, or 75. The Mooney viscosity ML 1+10 @ 121°C of the first branched, amorphous fluoropolymer can be less than 60, in some embodiments, in a range from 30 to 59, 31 to 59, 30 to 55, or 31 to 55. The Mooney viscosity ML 1+10 @ 121°C of the second substantially linear, amorphous fluoropolymer can be greater than 80, in some embodiments, at least 90, at least 95, or at least 100. In some embodiments, the Mooney viscosity ML 1+10 @ 121°C of the second substantially linear, amorphous fluoropolymer is in a range from 81 to 160, 85 to 160, 90 to 160, 95 to 160, 85 to 155, or 85 to 125. In other embodiments, the Mooney viscosity ML 1+10 @ 121°C of the second substantially linear, amorphous fluoropolymer can be less than 60, in some embodiments, in a range from 30 to 59, 31 to 59, 30 to 55, or 31 to 55. The Mooney viscosity ML 1+10 @ 121°C of the first branched, amorphous fluoropolymer can be greater than 80, in some embodiments, at least 90, at least 95, or at least 100. In some embodiments, the Mooney viscosity ML 1+10 @ 121°C of the first branched, amorphous fluoropolymer is in a range from 81 to 160, 85 to 160, 90 to 160, 95 to 160, 85 to 155, or 85 to 125.

In some embodiments, the second substantially linear, amorphous fluoropolymer is bimodal. In these embodiments, the co-coagulated mixture in the composition, method, and use according to the present disclosure can include a third substantially linear, amorphous fluoropolymer that is co-coagulated with the first and second amorphous fluoropolymers. In some embodiments, the difference between the Mooney viscosity ML 1+10 @ 121°C of the second substantially linear, amorphous fluoropolymer and the Mooney viscosity ML 1+10 @ 121°C of the third substantially linear, amorphous fluoropolymer can be up to 20, in some embodiments, less than 20 or up to 15 or up to 10. In some embodiments, the difference between the Mooney viscosity ML 1+10 @ 121°C of the second substantially linear, amorphous fluoropolymer and the Mooney viscosity ML 1+10 @ 121°C of the third substantially linear, amorphous fluoropolymer is greater than 20, in some embodiments, greater than 30, 40, or 50. In some embodiments, the difference between the Mooney viscosities ML 1+10 @ 121°C of the second and third amorphous fluoropolymers is up to 120, in some embodiments, up to 100, 90, 80, or 75. The Mooney viscosity ML 1+10 @ 121°C of one of the second or third substantially linear, amorphous fluoropolymers can be less than 60, in some embodiments, in a range from 30 to 59, 31 to 59, 30 to 55, or 31 to 55. The Mooney viscosity ML 1+10 @ 121°C of the other of the second or third substantially linear, amorphous fluoropolymer can be greater than 60, in some embodiments, at least 70, at least 80, at least 90, at least 95, or at least 100. In some embodiments, the Mooney viscosity ML 1+10 @ 121°C of the second or third substantially linear, amorphous fluoropolymer is in a range from 81 to 160, 85 to 160, 90 to 160, 95 to 160, 85 to 155, or 85 to 125. In embodiments of the composition, method, or use according to the present disclosure in which the co-coagulated mixture includes a third substantially linear, amorphous fluoropolymer, a weight ratio of the third substantially linear, amorphous nuoropolymer and the second substantially linear, amorphous fluoropolymer is in a range from 10:90 to 90: 10, in some embodiments, 20:80 to 80:20, 25:75 to 75:25, or 30:70 to 70:30.

Similarly, in some embodiments, the first branched, amorphous fluoropolymer is bimodal, and the co-coagulated mixture in the composition, method, and use according to the present disclosure can include a fourth branched, amorphous fluoropolymer that is co-coagulated with the first and second amorphous fluoropolymers. In these embodiments, the Mooney viscosities and differences in Mooney viscosities for the first and fourth branched, amorphous fluoropolymers can be any of those described above for the second and third substantially linear, amorphous fluoropolymers.

The Mooney viscosities described above of the first and second amorphous

fluoropolymers individually can be determined after separate coagulation. In some embodiments of the composition, method, and use according to the present disclosure, the co-coagulated mixture of the first amorphous fluoropolymer and the second amorphous fluoropolymer has a Mooney viscosity ML 1+10 @ 121°C in a range from 30 to 120, 30 to 110, 40 to 100, 30 to 90, 40 to 90, 30 to 60, 30 to 40, about 60 to about 90, about 60 to about 80, about 90 to about 100, or about 65 to about 75.

In some embodiments of the composition, method, or use according to the present disclosure, a weight ratio of the first branched, amorphous fluoropolymer and the second substantially linear, amorphous fluoropolymer is in a range from 10:90 to 90: 10, in some embodiments, 20:80 to 80:20, 25:75 to 75:25, or 30:70 to 70:30. In embodiments in which more than one branched or linear amorphous fluoropolymer is present, these ratios reflect the totals of branched and linear amorphous fluoropolymers in the co-coagulated mixture.

In embodiments in which the Mooney viscosity ML 1+10 @ 121 °C of the second substantially linear, amorphous fluoropolymer is greater than 90, 95, or 100, the second amorphous fluoropolymer may be present in an amount up to 75, 70, 60, 50, 40, 30, or 20 percent by weight, based on the total weight of the first and second amorphous fluoropolymers. It should be understood that the first branched, amorphous fluoropolymer would then make up the remainder of the total weight of the first and second fluoropolymer in these cases. The weight ratio of the first branched, amorphous fluoropolymer and the second substantially linear, amorphous fluoropolymer may be selected, for example, to achieve a Mooney viscosity ML 1+10 @ 121°C of a blend of the first and second amorphous fluoropolymers in a range from 30 to 120, 30 to 110, 40 to 100, 30 to 90, 40 to 90, 30 to 60, 30 to 40, about 60 to about 90, about 60 to about 80, about 90 to about 100, or about 65 to about 75. First and second amorphous fluoropolymers useful for practicing the present disclosure, including those described in any of the above embodiments, are typically prepared by a sequence of steps, which can include polymerization, co-coagulation, washing, and drying. In some embodiments, an aqueous emulsion polymerization can be carried out continuously under steady - state conditions. For example, an aqueous emulsion of monomers (e.g,. including any of those described above), water, emulsifiers, buffers and catalysts can be fed continuously to a stirred reactor under optimum pressure and temperature conditions while the resulting emulsion or suspension is continuously removed. In some embodiments, batch or semibatch polymerization is conducted by feeding the aforementioned ingredients into a stirred reactor and allowing them to react at a set temperature for a specified length of time or by charging ingredients into the reactor and feeding the monomers into the reactor to maintain a constant pressure until a desired amount of polymer is formed. After polymerization, unreacted monomers are removed from the reactor effluent latex by vaporization at reduced pressure. In some embodiments, a blend of the first and second amorphous fluoropolymers is prepared by mixing the latexes of the components (so-called latex blending) and subsequently finishing the mixture by co-coagulation.

The polymerization is generally conducted in the presence of a free radical initiator system, such as ammonium persulfate, potassium permanganate, AIBN, or bis(perfluoroacyl) peroxides. The polymerization reaction may further include other components such as chain transfer agents and complexing agents. The polymerization is generally carried out at a temperature in a range from 10 °C and 100 °C, or in a range from 30 °C and 80 °C. The polymerization pressure is usually in the range of 0.3 MPa to 30 MPa, and in some embodiments in the range of 2 MPa and 20 MPa.

When conducting emulsion polymerization, perfluorinated or partially fluorinated emulsifiers may be useful. Generally these fluorinated emulsifiers are present in a range from about 0.02% to about 3% by weight with respect to the polymer. Polymer particles produced with a fluorinated emulsifier typically have an average diameter, as determined by dynamic light scattering techniques, in range of about 10 nanometers (nm) to about 300 nm, and in some embodiments in range of about 50 nm to about 200 nm. If desired, the emulsifiers can be removed or recycled from the fluoropolymer latex as described in U.S. Pat. Nos. 5,442,097 (Obermeier et al.), 6,613,941 (Felix et al.), 6,794,550 (Hintzer et al.), 6,706,193 (Burkard et al.), and 7,018,541 (Hintzer et al.). In some embodiments, the polymerization process may be conducted with no emulsifier (e.g., no fluorinated emulsifier). Polymer particles produced without an emulsifier typically have an average diameter, as determined by dynamic light scattering techniques, in a range of about 40 nm to about 500 nm, typically in range of about 100 nm to about 400 nm, and suspension polymerization will typically produce particles sizes up to several millimeters. In some embodiments, a water soluble initiator can be useful to start the polymerization process. Salts of peroxy sulfuric acid, such as ammonium persulfate, are typically applied either alone or sometimes in the presence of a reducing agent, such as bisulfites or sulfinates (e.g., fluorinated sulfinates disclosed in U.S. Pat. Nos. 5,285,002 and 5,378,782 both to Grootaert) or the sodium salt of hydroxy methane sulfinic acid (sold under the trade designation "RONGALIT", BASF Chemical Company, New Jersey, USA). Most of these initiators and emulsifiers have an optimum pH-range where they show most efficiency. For this reason, buffers are sometimes useful. Buffers include phosphate, acetate or carbonate buffers or any other acid or base, such as ammonia or alkali metal hydroxides. The concentration range for the initiators and buffers can vary from 0.01% to 5% by weight based on the aqueous polymerization medium.

Aqueous polymerization using the initiators described above will typically provide amorphous fluoropolymers with polar end groups; (see, e.g., Logothetis, Prog. Polym. Sci., Vol. 14, pp. 257-258 (1989)). If desired, such as for improved processing or increased chemical stability, the presence of strong polar end groups such as S03^<_) and COO^<_) can be reduced in at least one of the first and second amorphous fluoropolymers through known post treatments (e.g., decarboxylation, post-fluorination). Chain transfer agents of any kind can significantly reduce the number of ionic or polar end groups. The strong polar end groups can be reduced by these methods to any desired level. In some embodiments, the number of polar functional end groups (e.g., -COF, -S0₂F, -SO₃M, -COO-alkyl, and-COOM, wherein alkyl is C₁-C₃ alkyl and M is hydrogen or a metal or ammonium cation), is reduced to less than or equal to 300, 200, or 100 per 10⁶ carbon atoms. In some embodiments, it may be useful to select initiators and polymerization conditions to achieve at least 300 polar functional end groups (e.g., -COF, -SO2F, -SO3M, -COO- alkyl, and -COOM, wherein alkyl is C₁-C₃ alkyl and M is hydrogen or a metal or ammonium cation) per 10⁶ carbon atoms, 400 per 10⁶ carbon atoms, or at least 500 per 10⁶ carbon atoms for at least one of the first or second amorphous fluoropolymers. When at least one of the first or second amorphous fluoropolymers has at least 300, 400, or 500 polar functional end groups per 10⁶ carbon atoms, the first or second may have increased interaction with a metal die surface as described in U.S. Pat. No. 5,132,368 (Chapman et al.) or may provide a melt-processable resin with improved moldability as described in U.S. Pat. Appl. No. 2011/0172338 (Murakami et al.) In some embodiments, one of the first or second amorphous fluoropolymer has at least 300, 400, or 500 polar functional end groups per 10⁶ carbon atoms, and the other of the first or second amorphous fluoropolymer has less than 300, 200, or 100 polar end groups per 10⁶ carbon atoms. If a first branched, amorphous fluoropolymer and a second substantially linear, amorphous fluoropolymer having different molecular weights are prepared and post-treated in the same way, the amorphous fluoropolymer having a lower molecular weight will typically have more polar end groups. The number of polar end groups can be determined by known infrared spectroscopy techniques.

Chain transfer agents and long-chain branching modifiers described above can be fed into the reactor by batch charge or continuously feeding. Because feed amount of chain transfer agent and/or long-chain branching modifier is relatively small compared to the monomer feeds, continuous feeding of small amounts of chain transfer agent and/or long-chain branching modifier into the reactor can be achieved by blending the long-chain branching modifier or chain transfer agent in one or more monomers.

Further examples of useful methods of making branched and linear amorphous fluoropolymers can be found, for example, in U.S. Pat. Nos. 7,375,157 (Amos et al) and 9,187,630 (Lavallee et al).

Adjusting, for example, the concentration and activity of the initiator, the concentration of each of the reactive monomers, the temperature, the concentration of the chain transfer agent, and the solvent using techniques known in the art can control the Mooney viscosity of the amorphous fluoropolymers.

In some embodiments, fluoropolymers useful for practicing the present disclosure have weight average molecular weights in a range from 10,000 g/mol to 200,000 g/mol. In some embodiments, the weight average molecular weight is at least 15,000, 20,000, 25,000, 30,000, 40,000, or 50,000 g/mol up to 100,000, 150,000, 160,000, 170,000, 180,000, or up to 190,000 g/mol. Fluoropolymers useful for practicing the present disclosure typically have a distribution of molecular weights and compositions. Weight average molecular weights can be measured, for example, by gel permeation chromatography (i.e., size exclusion chromatography) using techniques known to one of skill in the art.

To co-coagulate the obtained fluoropolymer latexes, any coagulant which is commonly used for coagulation of a fluoropolymer latex may be used, and it may, for example, be a water soluble salt (e.g., calcium chloride, magnesium chloride, aluminum chloride or aluminum nitrate), an acid (e.g., nitric acid, hydrochloric acid or sulfuric acid), or a water-soluble organic liquid (e.g., alcohol or acetone). The amount of the coagulant to be added may be in range of 0.001 to 20 parts by mass, for example, in a range of 0.01 to 10 parts by mass per 100 parts by mass of the fluoropolymer latex. When a coagulant is used, the latexes, either individually or combined, can be added to a solution (e.g., aqueous solution) of the coagulant, or a solution of the coagulant can be added to a mixture of the latexes. Alternatively or additionally, the combined fluoropolymer latexes may be frozen for co-coagulation. The coagulated fluoropolymer can be collected by filtration and washed with water. The washing water may, for example, be ion exchanged water, pure water or ultrapure water. The amount of the washing water may be from 1 to 5 times by mass to the fluoropolymer, whereby the amount of the emulsifier attached to the fluoropolymer can be sufficiently reduced by one washing.

Whether or not a mixture is a co-coagulated latex blend or results from mixing fluoropolymers after they are separately coagulated, filtered, washed, and dried may be determined by phase size in the fluoropolymer. In a co-coagulated blend, the phase size is expected to be comparable to the particle size in the source latex, which is typically in the range from 50 nm to 500 nm or any of the particle size ranges described above. Phase size may be determined, for example, by atomic force microscopy (AFM) using, for example, a phase imaging technique. On the other hand, fluoropolymers that are combined after they are separately coagulated, filtered, washed, and dried may have a phase size of up to several micrometers or several millimeters.

In some embodiments of the compositions and methods according to the present disclosure, the fluoropolymer can be used in combination with a polymer processing additive synergist. In some embodiments, the polymer processing additive synergist comprises at least one of poly(oxyalkylene) polymer, a silicone-polyether copolymer; an aliphatic polyester such as poly(butylene adipate), poly(lactic acid) and polycaprolactone polyesters; a

polytetrafluoroethylene (e.g., a polytetrafluoroethylene micropowder), an aromatic polyester such as phthalic acid diisobutyl ester, or a polyether polyol. Blends of any of these classes of synergists may be useful. Also, block copolymers including blocks of two or more of these classes of synergists may be useful. For examples, the polymer processing additive synergist may be silicone -polycaprolactone block copolymer or a poly(oxyalkylene)-polycaprolactone block copolymer. In some embodiments, the polymer processing additive synergist comprises at least one of polycaprolactone or a poly(oxy alkylene).

Poly(oxyalkylene) polymers and other synergists may be selected for their performance in polymer processing additive blends. The poly(oxyalkylene) polymer or other synergist may be selected such that it (1) is in the liquid state (or molten) at a desired extrusion temperature and (2) has a lower melt viscosity than both the host polymer and the polymer processing additive. In some embodiments, it is believed the poly(oxyalkylene) polymer or other synergist associates with the surface of the polymer processing additive particles in extrudable compositions. For example, the poly(oxyalkylene) polymer or other synergist may wet the surfaces of the polymer processing additive particles in extrudable compositions.

Poly(oxyalkylene) polymers useful as polymer processing additive synergists can be represented by formula A[(OR¹)_xOR²]_y, wherein A is typically alkylene interrupted by one or more ether linkages, y is 2 or 3, (OR')_s is a poly(oxyalkylene) chain having a plurality (x) of oxyalkylene groups, OR¹, wherein each R¹ is independently C2 to C5 alkylene, in some embodiments, C2 to C3 alkylene, x is about 3 to 3000, R² is hydrogen, alkyl, aryl, arylalkenyl, alkylarylenyl, -C(0)-alkyl, -C(0)-aryl, -C(0)-arylalkenyl, or -C(0)-alkylarylenyl, wherein -C(O)- is bonded to the O of OR². The variable "x" is selected such that molecular weight of the poly(oxyalkylene) polymer is in a range from about 200 to about 20,000 grams per mole (g/mol) or higher, in some embodiments about 400 to about 15,000 g/mol. In some embodiments, x is in a range from 5 to 1000 or 10 to 500. The poly(oxyalkylene) polymer chain can be a homopolymer chain such as poly(oxyethylene) in which each R¹ is -CH₂CH₂-, or poly(oxypropylene), in which each R¹ is -C3H6-. Or the poly(oxyalkylene) polymer chain can be a chain of randomly distributed oxyalkylene groups (e.g., a copolymer -OC2H4- and -OC3H6- units) or having alternating blocks of repeating oxyalkylene groups (e.g., a polymer comprising (-OC2H₄-)_a and (-OC3H₆-)b blocks, wherein a+b is in a range from 5 to 5000 or higher, in some embodiments, 10 to 500. In some embodiments, A is ethylene, -CH₂-CH(-)-CH₂- (derived from glycerol),

(derived from 1, 1,1 -trimethylol propane), poly(oxypropylene), -CH2CH2-O-CH2CH2-, or -CH₂CH₂-0- CH2CH2-O-CH2CH2-. In some embodiments, R² is hydrogen, methyl, butyl, phenyl, benzyl, acetyl, benzoyl, or stearyl. Other useful poly(oxyalkylene) polymers are polyesters prepared, for example, from dicarboxylic acids and poly(oxyalkylene) polymers represented by formula

A[(OR¹)_xOR²]y, wherein A, R¹, and x are as defined above, R² is hydrogen, and y is 2. Typically, the major proportion of the poly(oxyalkylene) polymer by weight will be the repeating oxyalkylene groups, (OR¹).

In some embodiments, the poly (oxyalkylene) polymers useful as polymer processing additive synergist are polyethylene glycols and their derivatives. Polyethylene glycol (PEG) can be represented by formula H(OC₂H₄)x OH, where x' is about 15 to 3000. Many of these polyethylene glycols, their ethers, and their esters are commercially available from a variety of sources. Polyethylene glycol-polycaprolactone block copolymers may also be useful.

While the first and second amorphous fluoropolymers can be used in combination with a polymer processing additive synergist, the examples below show that a blend of the first and second amorphous fluoropolymers is effective as a polymer processing additive in the absence of a synergist. Accordingly, the compositions according to the present disclosure can be essentially free of a polymer processing additive synergist, including any of those described above.

"Essentially free of a polymer processing additive synergist" can refer to compositions including a polymer processing additive synergist but in an amount that may be ineffective for improving the melt fracture performance during an extrusion when the polymer processing additive composition is included in a host resin. In some embodiments, the polymer processing additive composition may include up to or less than 1, 0.5, 0.25, or 0.1 percent by weight of a polymer processing additive synergist. Being "essentially free of a polymer processing additive synergist" can include being free of a polymer processing additive synergist. In embodiments in which the composition according to the present disclosure includes a polymer processing additive synergist, typically, the composition comprises between about 5 and 95 weight percent of the synergist and 95 and 5 weight percent of the amorphous fluoropolymers. The ratio of the amorphous fluoropolymers to the synergist component in the polymer processing additive can be from 2: 1 to 1 : 10, in some embodiments 1 : 1 to 1 :5.

In embodiments in which the composition according to or useful for practicing the present disclosure includes a poly(oxyalkylene) synergist, it may be useful for the composition to include a metal salt of a carboxylic acid, sulfonic acid, or alkylsulfate for thermally stabilizing the poly(oxyalkylene) polymer. In some embodiments, the metal salt is a metal salt of a carboxylic acid or a sulfonic acid. Carboxylic acids and sulfonic acids may be monofunctional or multifunctional (e.g., difunctional) and may be aliphatic or aromatic. In other words, the carbonyl carbon or sulfonyl sulfur may be attached to an aliphatic group or aromatic ring. Aliphatic carboxylic acids and sulfonic acids may be saturated or unsaturated. In addition to the one or more -C(0)0 or -S(0)20^~ anions (i.e., carboxylate or sulfonate groups, respectively), the aliphatic or aromatic group may also be substituted by other functional groups including halogen (i.e., fluoro, chloro, bromo, and iodo), hydroxyl, and alkoxy groups, and aromatic rings may also be substituted by alkyl groups. In some embodiments, the carboxylic acid or sulfonic acid is monofunctional or difunctional and aliphatic, without any further substituents on the aliphatic chain. In some embodiments, the carboxylic acid is a fatty acid, for example, having an alkyl or alkenyl group with about 8 to 30 (in some embodiments, 8 to 26 or 8 to 22) carbon atoms. The common names of the fatty acids having from eight to twenty six carbon atoms are caprylic acid (Cg), capric acid (Cio), lauric acid (Cn), myristic acid (CM), palmitic acid (C½), stearic acid (Cig), arachidic acid (C20), behenic acid (C22), lignoceric acid (C24), and cerotic acid (C26). Fatty acid metal salts of these acids may be caprylate, caprate, laurate, myristate, palmitate, stearate, arachidate, behenate, lignocerate, and cerotate salts, in some embodiments. In some embodiments the carboxylic acid is other than stearic acid. Examples of useful metal cations in the metal salt of a carboxylic acid, sulfonic acid, or alkylsulfate include aluminum (Al), calcium (Ca), magnesium (Mg), zinc (Zn), barium (Ba), lithium (Li), sodium (Na), and potassium (K). In some embodiments, the metal salt is a sodium or potassium salt. In some embodiments, the metal salt is a zinc or calcium salt. Examples of metal salts of a carboxylic acid, sulfonic acid, or alkylsulfate useful for thermally stabilizing a poly(oxyalkylene) polymer in compositions and methods according to the present disclosure include calcium stearate, zinc stearate, barium stearate, aluminum stearate, potassium stearate, magnesium stearate, sodium stearate, zinc acetate, sodium acetate, sodium caprylate, sodium laurate, sodium behenate, sodium 1-decane sulfonate, sodium lauryl sulfate, and zinc phthalate. In some embodiments, the metal salt is other than calcium stearate or zinc stearate. In some embodiments, the metal salt is other than calcium stearate. For more information regarding such metal salts and their ability to stabilize a poly(oxyalkylene) polymer, see Int. Pat. Appl. Publ. No. WO2015/042415 (Lavallee et al.).

In some embodiments, the first and second amorphous fluoropolymers disclosed herein can be used in combination with a silicone-containing polymer or another fluoropolymer polymer processing additive (e.g., a semicrystalline fluoropolymer). Semicrystalline fluoropolymers that are useful for at least partially alleviating melt defects in extrudable thermoplastic polymers and can be used in combination with the first and second amorphous fluoropolymer composition disclosed herein include those described, for example, in 5,527,858 (Blong et al.) and 6,277,919 (Dillon et al.). Some useful semicrystalline fluoropolymers include copolymers of vinylidene fluoride, tetrafluoroethylene, and hexafluoropropylene and are commercially available from 3M Company under the trade designations "DYNAMAR FX 5911", and "DYNAMAR FX 5912" and fluoropolymers available from Arkema, Colombes, France, under the trade designation "KYNAR" in various grades. Silicones that are useful for at least partially alleviating melt defects in extrudable thermoplastic polymers and can be used in combination with the first and second amorphous fluoropolymer disclosed herein include polysiloxanes described, for example, in U.S. Pat. No. 4,535,113 (Foster et al.), polydiorganosiloxane polyamide block copolymers and polydiorganosiloxane polyoxamide block copolymers described, for example, in U.S. Pat. App. Pub. No. 2011-0244159 (Papp et al.), and silicone-polyurethane copolymers described, for example, in Int. Pat. Appl. Publ. No. WO2015/042415 (Lavallee et al.). Some silicone polymer processing additives are commercially available, for example, from Dow Corning, Midland, Mich., under the trade designation "DOW CORNING MB50-002" and Wacker Chemie AG, Munich, Germany, under the trade designation "GENIOPLAST".

While the first and second amorphous fluoropolymer disclosed herein can be used in combination with another polymer processing additive, the examples below show that the first and second fluoropolymers are effective as a polymer processing additive in the absence of any other polymer processing additive. Accordingly, the compositions according to the present disclosure can be essentially free of other, different fluoropolymers (that is, not have the claimed first and second Mooney viscosities). "Essentially free of other, different fluoropolymers" can refer to compositions including other fluoropolymers but in an amount that may be ineffective for improving the melt fracture performance during an extrusion when the polymer processing additive composition is included in a host resin. In some embodiments, the polymer processing additive composition may include up to or less than 1, 0.5, 0.25, or 0.1 percent by weight of other, different fluoropolymers. Being "essentially free of other, different fluoropolymers" can include being free of other, different fluoropolymers. First and second amorphous fluoropolymers and blends thereof useful for practicing the present disclosure, which may include a polymer processing additive synergist, may be used in the form of powders, pellets, granules of the desired particulate size or size distribution, or in any other extrudable form. These compositions, useful as polymer processing additive compositions, can contain conventional adjuvants such as antioxidants, hindered amine light stabilizers (HALS), UV stabilizers, metal oxides (e.g., magnesium oxide and zinc oxide), antiblocks (e.g., coated or uncoated), pigments, and fillers (e.g., titanium dioxide, carbon black, and silica).

HALS are typically compounds that can scavenge free-radicals, which can result from oxidative degradation. Some suitable HALS include a tetramethylpiperidine group, in which the nitrogen atoms on the piperidine may be unsubstituted or substituted by alkyl or acyl. Examples of suitable HALS include decanedioic acid, bis (2,2,6,6-tetramethyl-l-(octyloxy)-4-piperidinyl)ester, bis(2,2,6,6-tetramethyl-4-piperidyl)sebacate, 8-acetyl-3-dodecyl-7,7,9,9-tetramethyl-l,3,8- triazaspiro(4,5)-decane-2,5-dione, bis(2,2,6,6-tetramethyl-4-hydroxypiperidine succinate), and bis(N-methyl-2,2,6,6-tetramethyl-4-piperidyl)secacate. Suitable HALS further include those available, for example, from BASF, Florham Park, NJ, under the trade designations

"CHIMASSORB". Examples of antioxidants include those obtained under the trade designations "IRGAFOS 168", "IRGANOX 1010" and "ULTRANOX 626", also available from BASF. These stabilizers, if present, can be included in the compositions according to the present disclosure in any effective amount, typically up to 5, 2, to 1 percent by weight based on the total weight of the composition and typically at least 0.1, 0.2, or 0.3 percent by weight.

In some embodiments, compositions according to the present disclosure and useful in the methods disclosed herein include a non-fluorinated host polymer. Generally, the non-fluorinated polymer is a thermoplastic, melt-processable polymer. The term "non-fluorinated" can refer to polymers having a ratio of fluorine atoms to carbon atoms of less than 1:2, in some embodiments, less than 1:3, 1 :5, 1 : 10, 1 :25, or 1: 100. A non-fluorinated, thermoplastic polymer may have no fluorine atoms. A wide variety of thermoplastic polymers are useful. Examples of useful thermoplastic polymers include non-fluorinated polymers such as hydrocarbon resins, polyamides (e.g., nylon 6, nylon 6/6, nylon 6/10, nylon 11 and nylon 12), polyester (e.g., poly(ethylene terephthalate), poly(butylene terephthalate), and poly(lactic acid) ), chlorinated polyethylene, polyvinyl resins (e.g., polyvinylchoride, polyacrylates and polymethylacrylates), polycarbonates, polyketones, polyureas, polyimides, polyurethanes, polyolefins and polystyrenes.

Useful melt-processable polymers have melt flow indexes (measured according to ASTM D1238 at 190 °C, using a 2160-gram weight) of 5.0 grams per 10 minutes or less, or 2.0 grams per 10 minutes or less. Generally the melt flow indexes of melt-processable polymers are at least 0.1 or 0.2 grams per 10 minutes. In some embodiments of the compositions and methods according to the present disclosure, useful thermoplastic polymers are hydrocarbon polymers, for example, polyolefins. Examples of useful polyolefins include those having the general structure CH₂=CHR³, wherein R³ is a hydrogen or alkyl. In some embodiments, the alkyl radical includes up to 10 carbon atoms or from one to six carbon atoms. Melt-processable polyolefins include polyethylene, polypropylene, poly(l-butene), poly(3-methylbutene), poly(4-methylpentene), copolymers of ethylene with propylene, 1-butene, 1-hexene, 1-octene, 1-decene, 4-methyl-l-pentene, and 1-octadecene, blends of polyethylene and polypropylene, linear or branched low-density polyethylenes (e.g. those having a density of from 0.89 to 0.94g/cm³), high-density polyethylenes (e.g., those having a density of e.g. from 0.94 to about 0.98 g/cm³), and polyethylene and olefin copolymers containing copolymerizable monomers (e. g., ethylene and acrylic acid copolymers; ethylene and methyl acrylate copolymers; ethylene and ethyl acrylate copolymers; ethylene and vinyl acetate copolymers; ethylene, acrylic acid, and ethyl acrylate copolymers; and ethylene, acrylic acid, and vinyl acetate copolymers). Melt-processable polymers include the metallic salts of the olefin copolymers, or blends thereof, which contain free carboxylic acid groups (e.g., polymers that include copolymerized acrylic acid). Illustrative of the metals that can be used to provide the salts of said carboxylic acids polymers are the one, two, and three valence metals such as sodium, lithium, potassium, calcium, magnesium, aluminum, barium, zinc, zirconium, beryllium, iron, nickel, and cobalt.

The polyolefins useful for practicing the present disclosure may be obtained by the homopolymerization or copolymerization of olefins. Useful polyolefins may be copolymers of one or more olefins and up to about 30 weight percent or more, in some embodiments, 20 weight percent or less, of one or more monomers that are copolymerizable with such olefins.

Representative monomers that are copolymerizable with the olefins include: vinyl ester monomers such as vinyl acetate, vinyl propionate, vinyl butyrate, vinyl chloroacetate, and vinyl

chloropropionate; acrylic and alpha-alkyl acrylic acid monomers and their alkyl esters, amides, and nitriles such as acrylic acid, methacrylic acid, ethacrylic acid, methyl acrylate, ethyl acrylate, N,N- dimethyl acrylamide, methacrylamide, and acrylonitrile; vinyl aryl monomers such as styrene, o- methoxystyrene, p-methoxystyrene, and vinyl naphthalene; vinyl and vinylidene halide monomers such as vinyl chloride, vinylidene chloride, and vinylidene bromide; alkyl ester monomers of maleic and fumaric acid and anhydrides thereof such as dimethyl maleate, diethyl maleate, and maleic anhydride; vinyl alkyl ether monomers such as vinyl methyl ether, vinyl ethyl ether, vinyl isobutyl ether, and 2-chloroethyl vinyl ether; vinyl pyridine monomers; N-vinyl carbazole monomers; and N-vinyl pyrolidine monomers. In some embodiments, a polyolefin useful in the compositions and methods disclosed herein is prepared by Ziegler-Natta catalysis. In some embodiments, a polyolefin useful in the compositions and methods disclosed herein is prepared by homogeneous catalysis. In some embodiments, homogeneous catalysis refers to catalysis in which the catalyst and the substrate are in the same phase (e.g., in solution). In some embodiments, homogeneous catalysis refers to catalysis carried out by catalysts having a single active site. Single site catalysts typically contain a single metal center.

In some embodiments, the homogeneously catalyzed polyolefin is a metallocene-catalyzed polyolefin. Metallocene catalysts typically have one or two cyclopentadienyl anions complexed to a positively charged metal such as zirconium, titanium, or hafnium. It is understood that the cyclopentadienyl groups can be substituted (e.g., by an alkyl, phenyl, or silyl group) or fused to an aromatic ring such as benzene, and two cyclopentadienyl groups or one cyclopentadienyl group and another coordinating group (e.g., N-alkyl, P-alkyl, O, or S) can be connected together through a bridging group (e.g., (CH₃)2Si, (CH₃)2C, or CH₂CH₂). The metal can include other ligands such as halogen, hydrogen, alkyl, phenyl, or an additional cyclopentadienyl group. Metallocene catalysts are typically used in combination with methyl alumoxane or borates under homogeneous reaction conditions.

Commercially available metallocene-catalyzed polyolefins include those from Exxon Chemical Company, Baytown, Tex., under the trade designations "EXXPOL", "EXACT", "EXCEED", and "VISTAMAXX", and from Dow Chemical Company, Midland, Mich., under the trade designations "AFFINITY" and "ENGAGE".

Homogeneous or single-site catalysts other than metallocene catalysts are also useful for providing homogeneously catalyzed polyolefins. Such catalysts typically include at least one first ligand strongly bonded to a metal (e.g., zirconium, titanium, hafnium, palladium, or nickel) and at least one other ligand that may be labile. The first ligands typically remain bonded to the metal after activation (e.g., by methyl alumoxane or borate), stabilize the single form of the catalyst, do not interfere with polymerization, provide shape to the active site, and electronically modify the metal. Some useful first ligands include bulky, bidentate diimine ligands, salicy limine ligands, tridentate pyridine diimine ligands, hexamethyldisilazane, bulky phenolics, and acetylacetonate. Many of these ligands are described, for example, in Ittel et al., Chem. Rev., 2000, 100, 1169- 1203. Other single site catalysts such as those described by Nova Chemicals Corporation, Calgary, Canada, under the trade designation "ADVANCED SCLAIRTECH TECHNOLOGY".

Homogeneously catalyzed polyolefins may have higher molecular weights, lower polydispersity, fewer extractables, and different stereochemistry than polyolefins made by other methods such as Ziegler-Natta catalysis. Homogeneous catalysis also allows for a broader selection of polymerizable monomers than Ziegler-Natta catalysis. Ziegler-Natta catalysis, which employs halogenated transition metal complexes mixed with organometallic compounds, can leave acidic residues in the resultant polyolefin resin. Acid-neutralizing additives such as calcium stearate and zinc stearate have been added to such resins. For homogeneously catalyzed polyolefins, such acidic residues are generally not present; therefore acid-neutralizing additives may not be required.

Examples of useful homogeneously catalyzed polyolefins include those having the general structure CH₂=CHR³, wherein R³ is a hydrogen or alkyl. In some embodiments, alkyl includes up to 10 carbon atoms or from one to six carbon atoms. Homogeneously catalyzed polyolefins can include polyethylene, polypropylene, poly(l-butene), poly(3-methylbutene), poly(4- methylpentene), copolymers of ethylene with propylene, 1-butene, 1-hexene, 1-octene, 1-decene, 4-methyl-l-pentene, and 1-octadecene, blends of polyethylene and polypropylene, linear or branched low-density polyethylenes (e.g. those having a density of from 0.89 to 0.94g/cm³), and high-density polyethylenes (e.g., those having a density of e.g. from 0.94 to about 0.98 g/cm³). In some embodiments, the homogeneously catalyzed polyolefin is linear low density polyethylene. In any of these embodiments, the homogeneously catalyzed polyolefin may be a metallocene- catalyzed polyolefin.

Compositions including non-fluorinated, thermoplastic polymers useful for practicing any of the embodiments of the present disclosure can contain any of the conventional adjuvants described above in any of their embodiments such as antioxidants, hindered amine light stabilizers (HALS), UV stabilizers, metal oxides (e.g., magnesium oxide and zinc oxide), antiblocks (e.g., coated or uncoated), pigments, and fillers (e.g., titanium dioxide, carbon black, and silica).

The non-fluorinated, thermoplastic polymers may be used in the form of powders, pellets, granules, or in any other extrudable form. Compositions according to the present disclosure can be prepared by any of a variety of ways. For example, the co-coagulated mixture of first and second amorphous fluoropolymers or blend thereof can be mixed with the non-fluorinated, thermoplastic polymers during the extrusion into polymer articles. Compositions according to the present disclosure can also include so-called masterbatches, which may contain the mixture of co- coagulated first and second amorphous fluoropolymers, further components (e.g., synergist or adjuvants described above), and/or one or more host thermoplastic polymers. A masterbatch can be a useful, diluted form of a polymer processing additive. Masterbatches can contain the co- coagulated first and second amorphous fluoropolymers, and optionally a synergist, dispersed in or blended with a host polymer, which can be a polyolefin, homogeneously catalyzed polyolefin, metallocene-catalyzed polyolefin, or any of the non-fluorinated thermoplastics described above. Preparation of a masterbatch may allow for more accurate amounts of a polymer processing additive to be added to an extrudable composition, for example. The masterbatch may be a composition ready to be added to a thermoplastic polymer for being extruded into a polymer article. Masterbatches, which include concentrations of polymer processing additives as described below, are often prepared at relatively high temperatures under aerobic conditions. In some embodiments in which the masterbatch includes a poly(oxyalkylene) polymer synergist, a metal salt of a carboxylic acid, sulfonic acid, or alkylsulfate as described above in any of its embodiments may be useful as a stabilizer.

The masterbatches can also be prepared by blending the co-coagulated first and second amorphous fluoropolymers with other additives to be used in the formulation and optionally polyethylene resin, and forming them into a compressed pellet using a method according to or similar to the one described in U.S. Pat. Appl. Publ. No. 2010/0298487 (Bonnet et al.).

The non-fluorinated, thermoplastic polymer (in some embodiments, polyolefin) to be extruded and the polymer processing additive composition can be combined together by any of the blending means usually employed in the plastics industry, such as with a compounding mill, a Banbury mixer, or a mixing extruder in which the polymer processing additive composition is uniformly distributed throughout the host thermoplastic polymer. The mixing operation is most conveniently carried out at a temperature above the softening point of fluoropolymer and/or the synergist although it is also possible to dry -blend the components as particulates and then cause uniform distribution of the components by feeding the dry blend to a twin-screw melt extruder. In some embodiments, the compositions and/or extrudable compositions according to the present disclosure can be made by mixing the co-coagulated first and second amorphous fluoropolymers, non-fluorinated, thermoplastic, and optionally synergist together simultaneously.

The resulting mixture can be pelletized or otherwise comminuted into a desired particulate size or size distribution and fed to an extruder, which typically will be a single-screw extruder, that melt-processes the blended mixture. Melt-processing typically is performed at a temperature from 180°C to 280°C, although optimum operating temperatures are selected depending upon the melting point, melt viscosity, and thermal stability of the blend. Different types of extruders that may be used to extrude the compositions disclosed herein are described, for example, by

Rauwendaal, C, "Polymer Extrusion", Hansen Publishers, p. 23-48, 1986. The die design of an extruder can vary, depending on the desired extrudate to be fabricated. For example, an annular die can be used to extrude tubing, useful in making fuel line hose, such as that described in U. S. Pat. No. 5,284, 184 (Noone et al.).

Compositions according to the present disclosure may be mixed with further non- fluorinated, thermoplastic polymer and/or further components to obtain a composition ready for processing into a polymer article. In other cases, the composition may contain all required ingredients and may be ready for being extruded into a polymer article. The amount of amorphous fluoropolymer in these compositions is typically relatively low. Accordingly, the non-fluorinated, thermoplastic polymer is present in a major amount in the some embodiments of the composition according to the present disclosure. A major amount would be understood to be greater than 50 percent by weight of the composition. In some embodiments, the major amount is at least 60, 70, 75, 80, or 85 percent by weight of the composition. The exact amount used may be varied depending upon whether the extrudable composition is to be extruded into its final form (e. g., a film) or whether it is to be used as a masterbatch or processing additive which is to be (further) diluted with additional host polymer before being extruded into its final form.

Generally, the composition according to the present disclosure that contains a non- fluorinated, thermoplastic polymer, which in some embodiments is a homogeneously catalyzed or metallocene-catalyzed polyolefin composition, includes the co-coagulated first and second amorphous fluoropolymers disclosed herein in a weight range from about 0.002 to 50 weight percent (in some embodiments, 0.002 to 10 weight percent), based on the total weight of the composition. In some of these embodiments, the weight of the co-coagulated first and second amorphous fluoropolymers and the polymer processing additive synergist is in a range from 0.01 percent to 50 percent (in some embodiments, 0.002 to 10 weight percent), based on the total weight of the composition. In a masterbatch composition, the weight of the co-coagulated first and second amorphous fluoropolymers and any polymer processing additive synergist can be in a range from 1 percent to 50 percent, in some embodiments, 1 percent to 10 percent, 1 percent to 5 percent, 2 percent to 10 percent, or 2 percent to 5 percent, based on the total weight of the composition. If the composition is to be extruded into final form and is not further diluted by the addition of host polymer, it typically contains a lower concentration of co-coagulated first and second amorphous fluoropolymers. In some of these embodiments, the combined weight of the co-coagulated first and second amorphous fluoropolymers and any polymer processing additive synergist is in a range from about 0.002 to 2 weight percent, in some embodiments about 0.01 to 1 weight percent, or 0.01 to 0.2 weight percent, based on the total weight of the composition. The upper concentration of polymer processing additive used is generally determined by economic limitations rather than by any adverse physical effect of the concentration of the polymer processing additive.

The compositions according to the present disclosure may be extruded or processed in a variety of ways, which includes for example, extrusion of films, extrusion blow molding, injection molding, pipe, wire and cable extrusion, and fiber production.

The examples, below, demonstrate that use of a combination of first and second amorphous fluoropolymers as a polymer processing additive is effective in reducing melt defects in thermoplastic polymers. A comparison of Example 1 with Counter Examples 1 and 2 and a comparison of Example 2 with Counter Example 3 in Table 4 shows that a co-coagulated mixture of a branched and a linear amorphous fluoropolymers has a time to clear melt fracture that unexpectedly is lower than that of the branched amorphous fluoropolymer on its own. A comparison of Example 4 with Counter Example 6 in Table 4 shows that the co-coagulated mixture of first and second amorphous fluoropolymers is more effective in reducing melt defects than a comparative blend of amorphous fluoropolymers in which the amorphous fluoropolymers are the same except that the amorphous fluoropolymers are mixed after being separately coagulated, filtered, washed, and dried. The same trend is observed when a poly(oxyalkylene) is present as shown in a comparison of Example 10 and Counter Example 8. These results are surprising, particularly in view U.S. Pat. 6,599,982 (Oriani) which teaches that two

fluoroelastomers used together as a polymer processing additive work better if they are introduced to an extrudable composition as separate components.

The beneficial effects of the co-coagulated mixture can be diminished when high shear conditions are used for combining the co-coagulated mixture with the non-fluorinated, thermoplastic polymer. Accordingly, in some embodiments, combining the co-coagulated mixture with the non-fluorinated, thermoplastic polymer is carried out using a specific energy input of less than 0.24 kW-h/kg.

Some Embodiments of the Disclosure

In a first embodiment, the present disclosure provides a composition comprising:

a co-coagulated mixture of a first branched, amorphous fluoropolymer and a second substantially linear, amorphous fluoropolymer, wherein the co-coagulated mixture has a gel content of less than five, 4, 3, 2, 1, 0.5, 0.25, or 0.1 percent by weight.

In a second embodiment, the present disclosure provides the composition of the first embodiment, wherein the first branched, amorphous fluoropolymer has a long chain branch index of at least 0.2.

In a third embodiment, the present disclosure provides the composition of the first or second embodiment, wherein the second substantially linear, amorphous fluoropolymer has a long chain branch index of less than 0.2.

In a fourth embodiment, the present disclosure provides the composition of any one of the first to third embodiments, wherein at least one of the first branched, amorphous fluoropolymer or the second substantially linear, amorphous fluoropolymer has a Mooney viscosity ML 1+10 @ 121°C in a range from 30 to 150. In a fifth embodiment, the present disclosure provides the composition of the fourth embodiment, wherein the co-coagulated mixture of a first branched, amorphous fluoropolymer a second substantially linear, amorphous fluoropolymer has a Mooney viscosity ML 1+10 @ 121°C in a range from 30 to 120.

In a sixth embodiment, the present disclosure provides the composition of any one of the third to fifth embodiments, wherein the difference between the Mooney viscosity ML 1+10 @ 121°C of the first branched, amorphous fluoropolymer and the Mooney viscosity ML 1+10 @ 121°C of the second substantially linear, amorphous fluoropolymer is in a range from 0 to less than 20.

In a seventh embodiment, the present disclosure provides the composition of any one of the first to sixth embodiments, wherein the second substantially linear, amorphous fluoropolymer has a Mooney viscosity ML 1+10 @ 121°C in a range from 30 to 59 or from 81 to 150.

In an eighth embodiment, the present disclosure provides the composition of any one of the first to seventh embodiments, wherein the co-coagulated mixture comprises the first branched, amorphous fluoropolymer, the second substantially linear, amorphous fluoropolymer, and a third substantially linear, amorphous fluoropolymer, wherein the second and third linear, amorphous fluoropolymers have different Mooney viscosities ML 1+10 @ 121°C.

In a ninth embodiment, the present disclosure provides the composition of the eighth embodiment, wherein the difference between the Mooney viscosity ML 1+10 @ 121 °C of the third substantially linear, amorphous fluoropolymer and the Mooney viscosity ML 1+10 @ 121°C of the second substantially linear, amorphous fluoropolymer is at least 20, 30, 40, or 50.

In a tenth embodiment, the present disclosure provides the composition of the eighth or ninth embodiment, wherein the second substantially linear, amorphous fluoropolymer has a Mooney viscosity ML 1+10 @ 121°C in a range from 30 to 59, and wherein the third substantially linear, amorphous fluoropolymer has a Mooney viscosity ML 1+10 @ 121°C in a range from 60 to 150.

In an eleventh embodiment, the present disclosure provides the composition of any one of the first to tenth embodiments, wherein a weight ratio of the first branched, amorphous fluoropolymer and the second substantially linear, amorphous fluoropolymer is in a range from 20:80 to 80:20.

In a twelfth embodiment, the present disclosure provides the composition of any one of the first to eleventh embodiments, wherein the first branched, amorphous fluoropolymer and the second substantially linear, amorphous fluoropolymer include the same or different monomer units of vinylidene fluoride, hexafluoropropylene, chlorotrifluoroethylene, 1- hydropentafluoropropylene, 2-hydropentafluoropropylene, tetrafluoroethylene, propylene, or a combination thereof.

In a thirteenth embodiment, the present disclosure provides the composition of any one of the first to twelfth embodiments, wherein the first branched, amorphous fluoropolymer is a copolymer comprising units of at least one of:

an olefin having a bromine or iodine atom bonded to a carbon of the double bond of the olefin;

an olefin represented by formula X^a2C=CX^a-Rp-Br or X^a2C=CX^a-Rp-I, wherein each X^a independently represents hydrogen, fluorine, bromine, chlorine or iodine, Rp is a perfluoroalkylene group, a perfluorooxyalkylene group or a perfluoropolyether group;

an olefin represented by formula CH2=CH-R 3-CH=CH2, wherein R 3 is a divalent perfluoroaliphatic group, optionally containing one or more O atoms, a perfluoroarylene group, and a perfluoroalkarylene group; or

an olefin represented by formula Ri R2C=C(R3)-W-C(R4)=CR5R6, wherein each Ri , R2, R3, R4, R5, and R6 is independently selected from H, F, an alkyl group having from 1 to 5 carbon atoms, and fluorinated alkyl group having from 1 to 5 carbon atoms; W is an alkylene or cycloalkylene group having from 1 to 18 carbon atoms, which may be linear or branched and which is optionally at least one of interrupted or terminated by oxygen atoms and which is optionally at least partially fluorinated.

In a fourteenth embodiment, the present disclosure provides the composition of the thirteenth embodiment, wherein the olefin represented by formula

Ri R₂C=C(R3)-W-C(R4)=CR₅R₆ is represented by formula

CY2=CX^b-(CF2)a-(0-CF(Z^a)-CF2)_b-0-(CF2)_c-(0-CF(Z^a)-CF₂)_d-(0)e-(CF(A))f-CX^b=CY2, wherein a is 0, 1, or 2; b is 0, 1, or 2; c is 0 to 8; d is 0, 1, or 2; e is 0 or 1; f is 0 to 6; Z^a is independently F or CF₃; A is F or a perfluorinated alkyl group; each X^b is independently H or F; and each Y is independently H, F, or CF₃.

In a fifteenth embodiment, the present disclosure provides the composition of any one of the first to fourteenth embodiments, further comprising at least one of a non-fluorinated thermoplastic polymer as a major component of the composition or a polymer processing additive synergist.

In a sixteenth embodiment, the present disclosure provides the composition of the fifteenth embodiment, wherein the composition comprises the polymer processing additive synergist, and wherein the polymer processing additive synergist comprises at least one of a poly (oxy alkylene) polymer, a silicone-polyether copolymer, an aliphatic polyester, an aromatic polyester, a polyether polyol, or a combination thereof.

In a seventeenth embodiment, the present disclosure provides the composition of the fifteenth or sixteenth embodiment, wherein the polymer processing additive synergist comprises at least one of a poly(oxyalkylene) polymer or a polycaprolactone.

In an eighteenth embodiment, the present disclosure provides the composition of the seventeenth embodiment, wherein the polymer processing additive synergist comprises the poly(oxyalkylene) polymer and further comprises a metal salt of a carboxylic acid, sulfonic acid, or alkylsulfate.

In a nineteenth embodiment, the present disclosure provides the composition of any one of the fifteenth to eighteenth embodiments, wherein the composition comprises the non-fluorinated polymer, and wherein the non-fluorinated polymer comprises at least one of a polyolefin, polyamide, polyimide, polyurethane, polyester, polycarbonate, polyketone, polyurea, polystyrene, polyvinyl chloride, polyacrylate, or polymethacrylate.

In a twentieth embodiment, the present disclosure provides the composition of the nineteenth embodiment, wherein the non-fluorinated, thermoplastic polymer is a polyolefin.

In a twenty -first embodiment, the present disclosure provides the composition of the twentieth embodiment, wherein the polyolefin is a homogeneously catalyzed polyolefin.

In a twenty-second embodiment, the present disclosure provides the composition of the twentieth or twenty -first embodiment, wherein the polyolefin is a metallocene-catalyzed polyolefin.

In a twenty -third embodiment, the present disclosure provides the composition of any one of the twentieth to twenty-second embodiments, wherein the polyolefin is a linear low density polyethylene.

In a twenty -fourth embodiment, the present disclosure provides the composition of any one of the fifteenth to twenty -third embodiments, wherein the co-coagulated mixture of the first branched and second substantially linear, amorphous fluoropolymer are present in a combined amount from 0.002 percent to 50 percent or 10 percent, based on the total weight of the composition.

In a twenty -fifth embodiment, the present disclosure provides the composition of any one of the first to twenty -fourth embodiments, further comprising at least one of a silicone-polyether copolymer, a silicone-polycaprolactone copolymer, a polysiloxane, a polydiorganosiloxane polyamide copolymer, a polydiorganosiloxane polyoxamide copolymer, or a silicone-polyurethane copolymer. In a twenty-sixth embodiment, the present disclosure provides a method of reducing melt defects during the extrusion of the non-fluorinated polymer, the method comprising extruding the composition of any one of the nineteenth to twenty -fourth embodiments.

In a twenty -seventh embodiment, the present disclosure provides a method of making the composition of any one of the fifteenth to twenty -fourth embodiments, the method comprising: providing a coagulum of a co-coagulated mixture of the first branched, amorphous fluoropolymer and the second substantially linear, amorphous fluoropolymer, and

combining a portion of the coagulum with at least one of the non-fluorinated, thermoplastic polymer or the polymer processing additive synergist.

In a twenty -eighth embodiment, the present disclosure provides a method of making a composition, the method comprising:

providing a coagulum of a co-coagulated mixture of a first branched, amorphous fluoropolymer and a second substantially linear, amorphous fluoropolymer, and

combining a portion of the coagulum with at least one of a non-fluorinated, thermoplastic polymer or a polymer processing additive synergist.

In a twenty-ninth embodiment, the present disclosure provides the method of the twenty- seventh or twenty-eighth embodiment, further comprising polymerizing components comprising one or more fluorinated monomers and at least one of:

olefin monomer having a bromine or iodine atom bonded to a carbon of the double bond of the olefin;

olefin monomer represented by formula X^a2C=CX^a-Rp-Br or X^a2C=CX^a-Rp-I, wherein each X^a independently represents hydrogen, fluorine, bromine, chlorine or iodine, Rf is a perfluoroalkylene group, a perfluorooxyalkylene group or a perfluoropolyether group;

olefin monomer represented by formula CH2=CH-R 3-CH=CH2, wherein Rf is a divalent perfluoroaliphatic group, optionally containing one or more O atoms, a perfluoroarylene group, and a perfluoroalkarylene group; or

olefin monomer represented by formula Ri R2C=C(R3)-W-C(R4)=CR5R6, wherein each

Ri , R2, R3, R4, R5, and R6 is independently selected from H, F, an alkyl group having from 1 to 5 carbon atoms, and fluorinated alkyl group having from 1 to 5 carbon atoms; W is an alkylene or cycloalkylene group having from 1 to 18 carbon atoms, which may be linear or branched and which is optionally at least one of interrupted or terminated by oxygen atoms and which is optionally at least partially fluorinated. In a thirtieth embodiment, the present disclosure provides the method of the twenty -ninth embodiment, wherein the olefin represented by formula Ri R2C=C(R3)-W-C(R4)=CR5R6 is represented by formula

CY2=CX^b-(CF2)a-(0-CF(Z^a)-CF2)b-0-(CF2)_c-(0-CF(Z^a)-CF₂)d-(0)e-(CF(A))f-CX^b=CY2, wherein a is 0, 1, or 2; b is 0, 1, or 2; c is 0 to 8; d is 0, 1, or 2; e is 0 or 1; f is 0 to 6; Z^a is independently F or CF₃; A is F or a perfluorinated alkyl group; each X^b is independently H or F; and each Y is independently H, F, or CF₃.

In a thirty -first embodiment, the present disclosure provides the method of any one of the twenty-seventh or thirtieth embodiments, wherein combining the co-coagulated mixture with the non-fluorinated, thermoplastic polymer is carried out using a specific energy input of less than 0.24 kW-h/kg.

In a thirty-second embodiment, the present disclosure provides a polymer processing additive composition comprising:

a co-coagulated mixture of a first branched, amorphous fluoropolymer a second substantially linear, amorphous fluoropolymer; and

a polymer processing additive synergist.

In a thirty -third embodiment, the present disclosure provides the polymer processing additive composition of the thirty-second embodiment, wherein the polymer processing additive synergist is a poly(oxyalkylene) polymer, a silicone-poly ether copolymer, an aliphatic polyester, an aromatic polyester, a poly ether polyol, or a combination thereof.

In a thirty -fourth embodiment, the present disclosure provides the polymer processing additive composition of the thirty-second or thirty -third embodiment, wherein the polymer processing additive synergist comprises at least one of a poly(oxyalkylene) polymer or a polycaprolactone.

In a thirty -fifth embodiment, the present disclosure provides the polymer processing additive composition of the thirty -fourth embodiment, wherein the polymer processing additive synergist comprises the poly(oxyalkylene) polymer and further comprises a metal salt of a carboxylic acid, sulfonic acid, or alkylsulfate.

In a thirty-sixth embodiment, the present disclosure provides use of a co-coagulated mixture of a first branched, amorphous fluoropolymer and a second substantially linear, amorphous fluoropolymer as a polymer processing additive.

In a thirty -seventh embodiment, the present disclosure provides the method, polymer processing additive composition, or use of any one of the twenty-eighth to thirty-sixth embodiments, wherein the first branched, amorphous fluoropolymer has a long chain branch index of at least 0.2. In a thirty -eighth embodiment, the present disclosure provides the method, polymer processing additive composition, or use of any one of the twenty-eighth to thirty -seventh embodiments, wherein the second substantially linear, amorphous fluoropolymer has a long chain branch index of less than 0.2.

In a thirty -ninth embodiment, the present disclosure provides the method, polymer processing additive composition, or use of any one of the twenty -eighth to thirty -eighth embodiments, wherein at least one of the first branched, amorphous fluoropolymer or the second substantially linear, amorphous fluoropolymer has a Mooney viscosity ML 1+10 @ 121°C in a range from 30 to 150.

In a fortieth embodiment, the present disclosure provides the method, polymer processing additive composition, or use of any one of the twenty-eighth to thirty -ninth embodiments, wherein the co-coagulated mixture of a first branched, amorphous fluoropolymer a second substantially linear, amorphous fluoropolymer has a Mooney viscosity ML 1+10 @ 121°C in a range from 30 to 120.

In a forty -first embodiment, the present disclosure provides the method, polymer processing additive composition, or use of any one of the twenty-eighth to fortieth embodiments, wherein the difference between the Mooney viscosity ML 1+10 @ 121°C of the first branched, amorphous fluoropolymer and the Mooney viscosity ML 1+10 @ 121°C of the second substantially linear, amorphous fluoropolymer is in a range from 0 to less than 20.

In a forty-second embodiment, the present disclosure provides the method, polymer processing additive composition, or use of any one of the twenty -eighth to forty -first embodiments, wherein the second substantially linear, amorphous fluoropolymer has a Mooney viscosity ML 1+10 @ 121°C in a range from 30 to 59 or from 81 to 150.

In a forty -third embodiment, the present disclosure provides the method, polymer processing additive composition, or use of any one of the twenty -eight to forty-second embodiments, wherein the co-coagulated mixture comprises the first branched, amorphous fluoropolymer, the second substantially linear, amorphous fluoropolymer, and a third substantially linear, amorphous fluoropolymer, wherein the second and third linear, amorphous fluoropolymers have different Mooney viscosities ML 1+10 @ 121°C.

In a forty -fourth embodiment, the present disclosure provides the method, polymer processing additive composition, or use of the forty -third embodiment, wherein the difference between the Mooney viscosity ML 1+10 @ 121 °C of the third substantially linear, amorphous fluoropolymer and the Mooney viscosity ML 1+10 @ 121 °C of the second substantially linear, amorphous fluoropolymer is at least 20, 30, 40, or 50. In a forty -fifth embodiment, the present disclosure provides the method, polymer processing additive composition, or use of the forty -third or forty -fourth embodiment, wherein the second substantially linear, amorphous fluoropolymer has a Mooney viscosity ML 1+10 @ 121°C in a range from 30 to 59, and wherein the third substantially linear, amorphous fluoropolymer has a Mooney viscosity ML l+10 @ 121°C in a range from 60 to 150.

In a forty -sixth embodiment, the present disclosure provides the method, polymer processing additive composition, or use of any one of the twenty-eighth to forty -fifth

embodiments, wherein a weight ratio of the first branched, amorphous fluoropolymer and the second substantially linear, amorphous fluoropolymer is in a range from 20:80 to 80:20.

In a forty-seventh embodiment, the present disclosure provides the method, polymer processing additive composition, or use of any one of the twenty-eighth to forty -sixth

embodiments, wherein the first branched, amorphous fluoropolymer and the second substantially linear, amorphous fluoropolymer include the same or different monomer units of vinylidene fluoride, hexafluoropropylene, chlorotrifluoroethylene, 1-hydropentafluoropropylene, 2- hydropentafluoropropylene, tetrafluoroethylene, propylene, or a combination thereof.

In a forty -eighth embodiment, the present disclosure provides the method, polymer processing additive composition, or use of any one of the twenty -eight to forty-seventh embodiments, wherein the first branched, amorphous fluoropolymer is a copolymer comprising units of at least one of:

an olefin represented by formula Ri R2C=C(R3)-W-C(R4)=CR5R6, wherein each Ri ,

R2, R3, R4, R5, and R6 is independently selected from H, F, an alkyl group having from 1 to 5 carbon atoms, and fluorinated alkyl group having from 1 to 5 carbon atoms; W is an alkylene or cycloalkylene group having from 1 to 18 carbon atoms, which may be linear or branched and which is optionally interrupted or terminated by oxygen atoms and which is optionally at least partially fluorinated. In a forty -ninth embodiment, the present disclosure provides the method, polymer processing additive composition, or use of the forty -eighth embodiment, wherein the olefin represented by formula Ri R2C=C(R3)-W-C(R_i)=CR5R6 is represented by formula

In a fiftieth embodiment, the present disclosure provides the composition, method, or use of any one of the first to forty -ninth embodiments, wherein at least one of the first or second amorphous fluoropolymers comprises copolymerized units of hexafluoropropylene units and vinylidene fluoride units.

In a fifty -first embodiment, the present disclosure provides the composition, method, or use of any one of the first to the fiftieth embodiments, wherein at least one of the first or second amorphous fluoropolymers is a terpolymer comprising copolymerized units of

hexafluoropropylene units, vinylidene fluoride units, and tetrafluoroethylene units.

In a fifty-second embodiment, the present disclosure provides the composition, method, or use of any one of the first to fifty -first embodiments, wherein a number of polar functional end groups (e.g., -COF, -S0₂F, -S0₃M, -COO-alkyl, and-COOM, wherein alkyl is C₁-C3 alkyl and M is hydrogen or a metal or ammonium cation) in at least one of the first or second amorphous fluoropolymers is less than or equal to 300, 200, or 100 per 10⁶ carbon atoms.

In a fifty -third embodiment, the present disclosure provides the composition, method, or use of any one of the first to fifty -first embodiments, wherein a number of polar functional end groups (e.g., -COF, -S0₂F, -S0₃M, -COO-alkyl, and-COOM, wherein alkyl is Ci-C₃ alkyl and M is hydrogen or a metal or ammonium cation) in at least one of the first branched, amorphous fluoropolymer or second substantially linear, amorphous fluoropolymers is greater than 300, 400, or 500 per 10⁶ carbon atoms.

In a fifty -fourth embodiment, the present disclosure provides the composition, method, or use of any one of the first to fifty -third embodiments, wherein the composition or the polymer processing additive composition further comprises at least one of an antioxidant or a hindered amine light stabilizer.

In order that this disclosure can be more fully understood, the following examples are set forth. It should be understood that these examples are for illustrative purposes only and are not to be construed as limiting this disclosure in any manner. EXAMPLES

Unless otherwise noted, all parts, percentages, ratios, etc. in the examples and the rest of the specification are by weight, and all reagents used in the examples were obtained, or are available, from general chemical suppliers such as, for example, Sigma-Aldrich Company, Saint Louis, Missouri, or may be synthesized by conventional methods.

These abbreviations are used in the following examples: PPA = polymer processing additive; FKM = fluoroelastomer; FP = fluoropolymer; MB = masterbatch; SEI = Specific energy input; % = weight percent, unless otherwise noted; MF = melt fracture; MV = Mooney viscosity; RPM = revolutions per minute; ppm = parts per million; g = grams; kg = kilograms; mg = milligrams; min = minutes; h = hour; °F = degrees Fahrenheit °C = degrees Celsius; mil = thousandths of an inch, μιη = micrometers; mm = millimeters; lb = pounds; gal = gallons; L = liters; mL = milliliters; kW = kilowatts; LLDPE = Linear Low Density Polyethylene, and L/D = length / diameter.

Table 1. Materials

Coagulation Procedures

Coagulation Procedure 1 (CP-1)

Two combined latexes, at a 50:50 ratio by volume, were filled into an addition funnel. A solution of MgCl2, n-butanol and water was prepared by adding 19 g MgCb. and 25 g n-butanol to 850 mL deionized water. This mixture was stirred with a paddle mixer until all the MgC was dissolved. The latex mixture was then dripped into the solution at a sufficiently slow flow rate that the agitation broke apart any coagulated fluoroelastomer chunks soon after they formed. This was continued until all the latex mixture had dripped into the MgCb. solution. Next, the coagulated fluoroelastomer was filtered on a double layer of cheesecloth. The coagulated fluoroelastomer was washed with deionized water at approximately 180 °F (82 °C). The collected fluoroelastomer was re-suspended in enough 180 °F (82 °C) deionized water to get to the same volume as the latex and MgCl2 solution. This was agitated with the paddle mixer for more than 5 min. This mixture was filtered on a double layered cheese cloth and the fluoroelastomer was washed in approximately 180 °F (82 °C) deionized water and re-suspended in deionized water as before. It was agitated for more than 5 min. Filtration, wash, re-suspension, agitation and wash was carried out one more time, for a total of three washes. At this point, the filtered and washed fluoroelastomer was laid out on a clean PTFE sheet in a glass baking tray. Clumps were broken up by hand and spread out for optimal drying before placing in an oven at approximately 70 °C overnight. Dried fluoroelastomer was stored in polyethylene bags.

Coagulation Procedure 2 (CP-2)

Into a clean, 5 gal (19 L) vessel, were placed 1000 g of deionized water and 12.5 g of MgCl2. The resulting mixture was stirred with a laboratory mixer until the salt was dissolved. To the salt solution was slowly added latex or blend of latexes. When all the latexes were added, the mixture was stirred for an additional 10 min. The water/crumb slurry was filtered through Saran cloth, and rinsed with an additional 500 mL water. Excess water was squeezed from the crumb, and it was returned to the coagulation vessel, and 2000 g water was added. This was stirred for 15 min and filtered as before. The crumb was thus rinsed and filtered a total of 4 times. The crumb was placed in flat pans lined with PTFE coated glass cloth or equivalent, and dried in an air circulating oven at 130 °C for 16 h.

Coagulation Procedure 3 (CP-3)

CP-3 was performed as described for CP-1, except that three combined latexes, at a 33:33:33 ratio by volume, were filled into the addition funnel. Preparative Example 1 (PE-1)

Latexes of FP-1 and FP-3 were blended and coagulated according to Coagulation Procedure 1 to provide PE-1. Preparative Examples and FKM 2 to 12

Preparative Examples or FKM 2 to 12 were prepared in a similar fashion to PE-1, except that the fluoropolymers and coagulation procedures used were as indicated in Table 2.

Table 2: Preparative Examples and FKM Preparations

PE-1 had a gel content of 0 percent by weight as determined by filtration of a 0.1% by weight solution in 2-butanone. The 0.1% solution was prepared by dissolving 100.0 mg of PE-1 in 99.90 g of 2-butanone. The solution was filtered twice through Whatman #54 filter paper. 10 ± 0.05 g of the solution was weighed into each of two aluminum weighing dishes. As controls, 10 ± 0.05 g of 2-butanone was weighed into each of two aluminum weighing dishes. The samples were allowed to dry in a fume hood and then placed in a vented oven at 120 °C for 15 minutes. The pans were weighed again, and the weight percent of gels were calculated after correcting for the weight of the 2-btuanone in the control weighing dishes. The weight percent of gels was -5.1% and -6.0% by weight, with an estimated measurement error of ± 2%.

At least PE-4 and PE-12, when evaluated for gel content using the filtration method described above, would also have a gel content of less than five percent by weight. Grinding Procedure

Dried fluoropolymer was frozen in liquid nitrogen and ground in a Thomas-Wiley mill. 1 weight % talc was added as a partitioning agent. Masterbatch Compounding

In the examples below indicated as comprising two FPs that were not co-coagulated, a 50:50 by weight ratio of the two indicated FPs was used in the indicated compounding method. For example, if an example indicated that FP A and FP B were compounded using CM-1, the 60 g of ground FP would comprise 29.7 g of ground FP A, 29.7 g of ground FP B, and 0.6 g talc.

Compounding Method 1 (CM-1): For Compounding Method 1, 2.0 g "IRGANOX", 1.4 g zinc stearate, and 1937 g EM 1002.09 were added to 60 g of ground FKM containing 10% talc partitioning agent (therefore 59.4 g of FKM + 0.6 g of talc). This mixture was tumble blended in a pail and subsequently fed to a laboratory, intermeshing, counter rotating, unvented, air cooled, conical twin screw extruder (Haake TW-100) with a front inside diameter of 19 mm. The mixture was gravity fed to the throat of the extruder, at approximately 50 g/min. The extruder specific temperature profile of the 3 barrel zones (feed, metering, mixing), and die zone was

170/190/200/200 °C respectively. The extruder was run at 150 RPM for the first "compounding" pass. Pellets from the first pass were tumble blended, then flood-fed for a second pass through the extruder, with the same temperature profile, but at 90 RPM. An approximately 4 min "purge" of material was discarded at the beginning of each pass.

Compounding Method 2 (CM-2): For Compounding Method 2, ingredients were mixed and blended as described in CM-1. The mixture was compounded using a single pass in a 25 mm co-rotating Berstorff Twin Screw Extruder, with a 50 L/D, using a temperature profile of

105/110/115/130/195/215/225/230/235/240 °C, an approximate feed rate of 89 g/min, and an approximate screw speed of 250 RPM. The feed rate and, secondarily, the screw speed were adjusted to yield an SEI of approximately 0.24 kW-h/kg.

Compounding Method 3 (CM-3): For Compounding Method 3, 40.2 g of PEG, 1.2 g of talc, 0.6 g of CaC0₃, 2.0 g "IRGANOX", 1.4 g zinc stearate, and 1937 g EM 1002.09 were added to 18 g of ground FKM, containing 10% talc partitioning agent,. This mixture was tumble blended in a pail. The mixture was compounded as described in CM-1.

Example 1 (EX-1)

EX-1 was prepared by compounding 60g of an additive formulation comprising 59.4 g of ground PE-1 and 0.6 g of talc into polyethylene, using compounding method 1. Example 2 through Example 12 (EX-2 through EX- 12) and Counter Example 1 through Counter Example 8 (CE-1 through CE-8)

EX-2 through EX-12 and CE-1 through CE-8 were prepared in a similar fashion to EX-1, except that the additive formulation and compounding method were varied. The details are listed in Table 3, below. For CE-4, the additive formulation comprised 29.7 g of each of PE-2 and PE-3. For CE-6 and CE7, the additive formulation comprised 29.7 g of each PE-5 and PE-6. For EX-3 and EX-10, the additive formulation comprised 18 g of PE, 40.2 g of PEG, 1.2 g of talc and 0.6g of CaC0₃. For CE-8 (MB- 18), the additive formulation comprised 9 g of PE-10, 9 g of PE-11, 40.2 g of PEG, 1.2 g of talc and 0.6g of CaC0₃.

Table 3. FKMs and compounding methods used to produce Examples and Counter Examples

N/A = Not Applicable

Blown Film Testing

Melt fracture (MF) elimination performance of these materials (as PPAs) was tested in

"MARFLEX 7109" LLDPE. This was performed on a Kiefel pilot scale, blown film line with a 40 mm, 24/1 L/D grooved feed extruder, a 40 mm diameter spiral die with a 36 mil (0.9 mm) gap. Formulations charged to the film line were prepared by dry blending the appropriate masterbatch with "MARFLEX 7109" LLDPE, 7500 ppm of antiblock (using 60% masterbatch from Ampacet #101558), 1500 ppm slip (from a 5% erucamide masterbatch, Ampacet #10090), and 350 ppm of PPA from one of the 3% masterbatch types discussed before. Film was produced at 220 1/s shear rate, at a melt temperature of 410 °F (210 °C), a nominal thickness of 1 mil (25.4 μιη), with a feed rate of approximately 22.5 lbs/h (10.2 kg/h).

Film die exit pressure was recorded every 10 min and a sample of film was collected. Remaining melt fracture on Film was measured and expressed as a percentage of the total film width. Time corresponding to the disappearance of MF or time to clear melt fracture was recorded (TTC), at which point the test was stopped. If any MF was remaining at the end of two h, the test was stopped and the final MF level recorded.

Table 4

NR = Not Recorded

Various modifications and alterations of this disclosure may be made by those skilled the art without departing from the scope and spirit of the disclosure, and it should be understood that this invention is not to be unduly limited to the illustrative embodiments set forth herein.

Claims

What is claimed is:

1. A composition comprising a co-coagulated mixture of a first branched, amorphous fluoropolymer and a second substantially linear, amorphous fluoropolymer, wherein the co- coagulated mixture has a gel content of less than five percent by weight.

2. The composition of claim 1, wherein the first branched, amorphous fluoropolymer has a long chain branch index of at least 0.2.

3. The composition of claim 1 or 2, wherein the second substantially linear, amorphous fluoropolymer has a long chain branch index of less than 0.2.

4. The composition of any one of claims 1 to 3, wherein at least one of the first branched, amorphous fluoropolymer or the second substantially linear, amorphous fluoropolymer has a Mooney viscosity ML 1+10 @ 121°C in a range from 30 to 150.

5. The composition of claim 4, wherein the co-coagulated mixture of a first branched, amorphous fluoropolymer a second substantially linear, amorphous fluoropolymer has a Mooney viscosity ML 1+10 @ 121°C in a range from 30 to 120.

6. The composition of any one of claims 1 to 5, wherein a weight ratio of the first branched, amorphous fluoropolymer and the second substantially linear, amorphous fluoropolymer is in a range from 20:80 to 80:20.

7. The composition of any one of claims 1 to 6, wherein the first branched, amorphous fluoropolymer and the second substantially linear, amorphous fluoropolymer include the same or different monomer units of vinylidene fluoride, hexafluoropropylene, chlorotrifluoroethylene, 1- hydropentafluoropropylene, 2-hydropentafluoropropylene, tetrafluoroethylene, propylene, or a combination thereof.

8. The composition of any one of claims 1 to 7, wherein the first branched, amorphous fluoropolymer is a copolymer comprising units of at least one of:

an olefin having a bromine or iodine atom bonded to a carbon of the double bond of the olefin; an olefin represented by formula X^a2C=CX^a-Rp-Br or X^a2C=CX^a-Rp-I, wherein each X^a independently represents hydrogen, fluorine, bromine, chlorine or iodine, Rp is a perfluoroalkylene group, a perfluorooxyalkylene group or a perfluoropolyether group;

an olefin represented by formula Ri R2C=C(R3)-W-C(R4)=CR5R6, wherein each Ri ,

R2, R3, R4, R5, and R₆ is independently selected from H, F, an alkyl group having from 1 to 5 carbon atoms, and fluorinated alkyl group having from 1 to 5 carbon atoms; W is an alkylene or cycloalkylene group having from 1 to 18 carbon atoms, which may be linear or branched and which is optionally at least one of interrupted or terminated by oxygen atoms and which is optionally at least partially fluorinated.

9. The composition of any one of claims 1 to 8, further comprising a polymer processing additive synergist, wherein the polymer processing additive synergist comprises at least one of a poly(oxyalkylene) polymer, a silicone-polyether copolymer, an aliphatic polyester, an aromatic polyester, or a polyether polyol.

10. The composition of any one of claims 1 to 9, further comprising a non-fluorinated thermoplastic polymer, wherein the non-fluorinated thermoplastic polymer comprises at least one of a polyolefin, polyamide, polyimide, polyurethane, polyester, polycarbonate, polyketone, polyurea, polystyrene, polyvinyl chloride, polyacrylate, or polymethacrylate.

11. The composition of claim 10, wherein the non-fluorinated polymer comprises at least one polyolefin.

12. A method of reducing melt defects during the extrusion of the non-fluorinated polymer, the method comprising extruding the composition of claim 10 or 11.

13. A method of making the composition of any one of claims 9 to 12, the method comprising: providing a coagulum of a co-coagulated mixture of the first branched, amorphous fluoropolymer the second substantially linear, amorphous fluoropolymer, and

14. The method of claim 13, further comprising polymerizing components comprising one or more fluorinated monomers and at least one of:

olefin monomer represented by formula X^a2C=CX^a-Rp-Br, wherein each X^a independently represents hydrogen, fluorine, bromine, chlorine or iodine, Rp is a perfluoroalkylene group, a perfluorooxyalkylene group or a perfluoropolyether group;

olefin monomer represented by formula CH2=CH-R 3-CH=CH2, wherein R 3 is a divalent perfluoroaliphatic group, optionally containing one or more O atoms, a perfluoroarylene group, and a perfluoroalkarylene group; or

olefin monomer represented by formula Ri R2C=C(R3)-W-C(R4)=CR5R6, wherein each

Ri , R2, R3, R4, R5, and Re is independently selected from H, F, an alkyl group having from 1 to 5 carbon atoms, and fluorinated alkyl group having from 1 to 5 carbon atoms; W is an alkylene or cycloalkylene group having from 1 to 18 carbon atoms, which may be linear or branched and which is optionally at least one of interrupted or terminated by oxygen atoms and which is optionally at least partially fluorinated.

15. Use of a co-coagulated mixture of a first branched, amorphous fluoropolymer and a second substantially linear, amorphous fluoropolymer as a polymer processing additive.