EP0783538A1 - Melanges polymeres a base de resines polypropylene et polybutylene-terephtalate - Google Patents

Melanges polymeres a base de resines polypropylene et polybutylene-terephtalate

Info

Publication number
EP0783538A1
EP0783538A1 EP94930367A EP94930367A EP0783538A1 EP 0783538 A1 EP0783538 A1 EP 0783538A1 EP 94930367 A EP94930367 A EP 94930367A EP 94930367 A EP94930367 A EP 94930367A EP 0783538 A1 EP0783538 A1 EP 0783538A1
Authority
EP
European Patent Office
Prior art keywords
polypropylene
extruder
polybutylene terephthalate
peroxide
compound
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Withdrawn
Application number
EP94930367A
Other languages
German (de)
English (en)
Inventor
Hans Kristian Kotlar
Guo Hua Hu
Yi Jun Sun
Morand Lambla, Deceased
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Borealis AS
Original Assignee
Borealis AS
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Borealis AS filed Critical Borealis AS
Publication of EP0783538A1 publication Critical patent/EP0783538A1/fr
Withdrawn legal-status Critical Current

Links

Classifications

    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
    • C08L67/00—Compositions of polyesters obtained by reactions forming a carboxylic ester link in the main chain; Compositions of derivatives of such polymers
    • C08L67/02—Polyesters derived from dicarboxylic acids and dihydroxy compounds
    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08F—MACROMOLECULAR COMPOUNDS OBTAINED BY REACTIONS ONLY INVOLVING CARBON-TO-CARBON UNSATURATED BONDS
    • C08F255/00—Macromolecular compounds obtained by polymerising monomers on to polymers of hydrocarbons as defined in group C08F10/00
    • C08F255/02—Macromolecular compounds obtained by polymerising monomers on to polymers of hydrocarbons as defined in group C08F10/00 on to polymers of olefins having two or three carbon atoms
    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
    • C08L23/00—Compositions of homopolymers or copolymers of unsaturated aliphatic hydrocarbons having only one carbon-to-carbon double bond; Compositions of derivatives of such polymers
    • C08L23/02—Compositions of homopolymers or copolymers of unsaturated aliphatic hydrocarbons having only one carbon-to-carbon double bond; Compositions of derivatives of such polymers not modified by chemical after-treatment
    • C08L23/10—Homopolymers or copolymers of propene
    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
    • C08L51/00—Compositions of graft polymers in which the grafted component is obtained by reactions only involving carbon-to-carbon unsaturated bonds; Compositions of derivatives of such polymers
    • C08L51/06—Compositions of graft polymers in which the grafted component is obtained by reactions only involving carbon-to-carbon unsaturated bonds; Compositions of derivatives of such polymers grafted on to homopolymers or copolymers of aliphatic hydrocarbons containing only one carbon-to-carbon double bond

Definitions

  • This invention relates to a process of producing a polymeric blend based on polypropylene (PP) and polybutylene terephthalate (PBT) polymers, and a compatibilized blend of polypropylene and polybutylene terephthalate polymers, having synergistic properties of both said polymers produced by the process. More particular the invention relates to a process comprising a simultaneous grafting of two different monomers, an allylepoxy compound and a styrenic compound, onto the polypropylene polymer resin, and a subsequent blending of the grafted resin with polybutylene terephthalate, the entire process being performed at grafting conditions. This in situ grafting and blending process is accomplished with the polyme ⁇ ric resins in their molten state by means of a singel step reactive extrusion process. The obtained blends have high elongations at break and improved impact strengths.
  • PP polypropylene
  • PBT polybutylene terephthalate
  • Modifications of the chemically inert polypropylene by grafting in order to achieve compositions having specific properties is previously known. Such grafting processes may be performed at extrusion conditions. Further, the blending of a grafted polypropylene resin with a different polymer resin to obtain compositions having improved properties, is also known.
  • EP 0.280.454 discloses a method for the grafting of at least two different monomers onto molten hydrocarbon poly ⁇ mer.
  • the polymer is a homopolymer of propylene, a high density polyethylene or a linear low density polyethy ⁇ lene, and the monomers are styrene or maleic anhydride. The process is operated in the absence of an initiator for the grafting reaction and in the substantial absence of antioxi- dant in the polymer, by the use of an extruder at extrusion conditions.
  • NO patent application no. 924786 relates to polypro ⁇ pylene compositions grafted with glycidyl acrylate or glycidyl methacrylate (GMA) using an organic peroxide as a radicalgene- rating agent, performed by kneading the melted mixture, prefe- rably in an inert atmosphere.
  • GMA glycidyl acrylate or glycidyl methacrylate
  • US 5.079.295 relates to a thermoplastic composition
  • a thermoplastic composition comprising a polyphenylene ether resin, a modified propylene polymer and a rubbery substance.
  • the polypropylene component is grafted with a styrene-based monomer and an unsaturated carboxylic acid or its derivative.
  • the patent describes a number of grafting processes, however in- the working examples 100 parts by weight of polypropylene are mixed with one part of maleic anhydride (MAH), one part of styrene and one part of peroxide in a mixer, and subsequently extruded at 220°C.
  • MAH maleic anhydride
  • an aquous dispersion of polypropylene, styrene and MAH introduced into an autoclave is allowed to react at 120°C.
  • the MAH of the disper ⁇ sion is replaced by glycidyl methacrylate or glycidyl acry- late.
  • polypropylene has a too low stiffness.
  • polybutylene tereph- thalate has a high stiffness, but is difficult to process because of the required high processing temperature, and it is prone to hydrolysis.
  • polybutylene terephthalate is a high-priced resin. Therefore, it will be desirable to combine polypropylene and polybutylene terephthalate into one blend having intermediate properties, and being processable in equipment used to process polypropylene.
  • This problem may be solved by performing the grafting and the blending processes in the presence of a compound having a stabilizing effect on the intermediate polymeric radicals created during the processes. Moreover, a continuous grafting and blending process combined in one operation would have obvious advantages, both economically and technically.
  • the present invention thus provides a process of producing an in situ compatibilized blend of polypropylene and polybutylene terephthalate polymers by a continuous single step extrusion process performed in an extruder, preferably in an inert atmosphere, comprising the steps of:
  • R is H or a C ⁇ alkyl
  • R x is -(CH 2 ) n -; -C(0)0-(CH 2 ) n -; or -(CH 2 ) n -0-
  • n is an integer of 1 to 4
  • a styrenic compound having the formula:
  • R 2 is H, OH, CH 3 or allyl; and a peroxide as an initiator, the reagents being heated to a temperature which is higher than the melting point of the polypropylene polymer and the decomposition temperature of said peroxide while being subjec- ted to continuous intimate mixing, and
  • step (ii) introducing a neat polybutylene terephthalate into a second feed zone of the extruder downstream the first one at a position where said polypropylene polymer of step (i) is in a molten state to achieve a melting and intimate mixing of said polybutylene terephthalate with said melted polypro ⁇ pylene resin, and
  • the present invention also provides a compatibilized blend of polypropylene and polybutylene terephthalate having synergistic properties of both said polymers produced by the process described above.
  • the obtained blend may be used as an engineering plastic in the manufacturing of articles for technical use.
  • the polypropylene resins that may be used in the in situ grafting and blending process comprise polypropylene homopolymers, and copolymers of propylene with ethylene and/or butadiene, in particular resins having a molecular weight of 150,000 to 500,000 and a melt flow index of 0.2 to 100 g/10 minutes, preferably 0.2 to 50 g/10 minutes, determined at
  • copolymers 230 ⁇ C and 2.16 kg load according to the method of ASTM D 1238.
  • Said copolymers have an ethylene content preferably between 0 and 20 % by weight.
  • the polypropylene resin may be used in the form of granules or as a powder, preferbly as a flowable powder.
  • Polybutylene terephthalate resins of commercial grades in the form of conventional pellets without any further additives may be used. It is essential that the polybutylene terephthalate resin has a certain amount of free carboxylic and hydroxylic end groups, preferably at least 0.42 meq/kg of COOH and 0.35 meq/kg of OH groups. However, resins having lower amounts of said groups may also give blends of accep ⁇ table properties.
  • the monomeric allylepoxy compound to be grafted onto the polymer chains must contain polar or" functional substi- tuents.
  • Said monomers are preferably chosen from the group comprising allylepoxy compounds having the formula: 0
  • R is H or a C 1 . i alkyl; R j is -(CH 2 ) n -; -C(0)0-(CH 2 ) n -; 5 or -(CH 2 ) n -0-; and n is an integer of 1 to 4.
  • R is H or CH 3 , more preferably CH 3 .
  • R ⁇ is preferably -C(0)0-(CH 2 ) n -.
  • the most preferred compound is glycidyl methacrylate.
  • Suitable styrenic compounds are those having the formula:
  • R 2 is H, making styrene the preferred styrenic compound.
  • the styrenic compound 5 is assumed to stabilize by delocalization the free radical species being present during the grafting process.
  • any free radical o generating peroxide compound known in the art having a suit ⁇ able decomposition temperature may be used.
  • Intimate mixing of the polypropylene resin, the initiator and the grafting monomers at a temperature higher than both the melting point of the polypropylene resin and the peroxide decomposition temperature is a prerequisite for achieveing a desired degree of grafting onto the polypropylene resin.
  • the extruder must be provided with two feed hoppers, one located at the main feeding point of the extruder, and the other one located in a ⁇ o distance of approximately 0.4 L downstream of the first one.
  • Each hopper is connected with a feeding device, from which the starting material is continuously fed at a controlled rate.
  • the extruder barrel thus becomes divided into two main zones, a first zone between the two hoppers, and a second zone be- i5 tween the second hopper and the die.
  • the polypropylene resin is fed to the first feeder together with the allylepoxy compound, the styrenic compound and the initiator, which may be premixed before being conveyed to the first feed hopper.
  • the grafting monomers used are glycidylalkyl acry ⁇ late and styrene. It is convenient first to mix the glycidyl ⁇ alkyl acrylate with styrene and then dissolve the peroxide initiator in this mixture, which subsequently is mixed into the polypropylene powder.
  • the first main extruder zone should comprise a concentration of glycidyl methacrylate of 1 to 10% by weight, preferably 2 to 5% by weight, and a concentration of styrene of 1 to 10% by weight, preferably 2 to 5% by weight, calculated on the basis of the neat polypropylene resin.
  • initiator is approximately 0.2 to 0.3 % by weight of the polypropylene resin.
  • the polybutylene terephthalate is conveyed to the second hopper, from which it is introduced into the extruder.
  • 35 polybutylene terephthalate resin fed to the extruder is chosen in respect of the desired properties of the final material.
  • the temperature in the first main extruder zone should be approximately 200°C.
  • the preferred peroxide initiator "Perkadox-14" has a half-life of 6.5 seconds.
  • the temperature should be raised to s about 240°C to ensure that the introduced polybutylene tereph ⁇ thalate is rapidly melted and mixed with the molten grafted polypropylene.
  • the present extrusion process is preferably carried out in an inert atmosphere, most preferably in a nitrogen s atmosphere. This can readily be accomplished by flushing the feed hoppers with nitrogen.
  • the polymer chain scissions and hence the molecular weights of the present blends can be controlled by the use of the comonomer system described herein.
  • the styrenic compound will function as a chain transfer agent.
  • the present process can be performed with less degradation of the polypropylene resin.
  • the styrenic compound also acts as a comonomer, reacting with the allylepoxy monomer to give random copoly ⁇ mers.
  • the side chains grafted onto the polypropylene backbone are random copolymers of said two species.
  • the simul ⁇ taneous grafting with the two monomers provides a synergistic effect resulting in a higher grafting efficiency and a higher amount of monomers being grafted onto the polypropylene resin compared to other grafting processes, which increases its number of polar groups. It is assumed that said polar groups will react with the functional end groups of the polybutylene terephthalate at the interfaces between the polypropylene and polybutylene terephthalate fractions. Hence, there will be a minor amount of crosslinking between the polypropylene and polybutylene terephthalate resins with the allylepoxy compound as the bridging species.
  • the polymeric blends of the present invention can be used as a single resin without any further compounding. Con ⁇ ventional additives such as colorants, antistatics, UV stabi ⁇ lizers, etc. may be added if desired, in manners well known in the art.
  • the present blends of polypropylene and polybutylene terephthalate show synergistic effects in respect of such properties as stiffnes, impact strength and elongation at yield, which are clearly demonstrated by the values of said properties shown in Table 3 below.
  • the obtained blends behave like one material in use, and the obtained properties being between the properties of the neat resin components, is a strong indication of the blend being truly homogeneous.
  • extruder used in the examples is a ZSK30 Werner &
  • the temperatu- res of the extruder are adjusted at 200 ⁇ C in the first zone between said two feed hoppers, and at 240°C downstream of the second feed hopper and at the die.
  • compositions are subjected to mechanical testing according to standardized procedures. Based on the stress-strain curves obtained by tensile testing modulus of elasticity, stress at yield and elongation at break are deter ⁇ mined. The modulus of elasticity is determined according to ISO 527, while the stress at yield and elongation at break are s determined according to ASTM D 638. The impact strength is determined as the total energy of break by dropping a load onto a 3 mm thick sheet of 0 ⁇ C according- to standardized ISO procedure of ISO.
  • Polypropylene powder moistened with a liquid mixture of glycidyl methacrylate (GMA), styrene and a peroxide initia ⁇ tor ( "Perkadox-14" ) is introduced into the extruder barrel at 0 the first feeding point and extruded at the conditions speci ⁇ fied above.
  • Polybutylene terephthalate pellets with no mono ⁇ mers or initiator added is introduced into the extruder barrel at the second feeding point.
  • the PP/GMA/styrene/initiator weight ratios are 100/3.0/3.0/0.3, giving a styrene/GMA ratio 5 of 1.4 on a molar basis.
  • the experimental details are given in table 1.
  • the physical properties of the obtained blends are presented in table 3.
  • Comparative example 6 The procedure and extrusion conditions of example 5 are used, except that the feeding rate of the premixed polypropylene resin is 2.8 kg/h, and the feeding rate of the neat polybuty ⁇ lene terephthalate pellets is 1.2 kg/h, and both the polypro ⁇ pylene premix and the polybutylene terephthalate are fed to the first feed hopper and together continuously introduced into the extruder barrel without being exposed to any parti ⁇ cular mixing. Experimental details are given in table 2. The physical properties of the obtained blend are presented in table 3.
  • Polypropylene powder without any monomers or peroxide initia ⁇ tor added, and neat polybutylene terephthalate pellets are separately introduced into the extruder barrel at the first and second feeding points, respectively, and extruded at the conditions specified above.
  • the feeding rates of the polypro ⁇ pylene powder and the polybutylene terephthalate pellets are as indicated in table 2.
  • the mechanical properties of the obtained blends are presented in table 3.

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  • Chemical & Material Sciences (AREA)
  • Health & Medical Sciences (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Medicinal Chemistry (AREA)
  • Polymers & Plastics (AREA)
  • Organic Chemistry (AREA)
  • Extrusion Moulding Of Plastics Or The Like (AREA)
  • Compositions Of Macromolecular Compounds (AREA)

Abstract

L'invention concerne un procédé pour produire un mélange de résines polypropylène et polybutylène-téréphtalate rendues mutuellement compatibles par un procédé d'extrusion continue en une seule étape utilisant une extrudeuse, de préférence dans une atmosphère inerte. Ce procédé consiste à: (i) introduire dans une première zone d'alimentation de l'extrudeuse un polymère polypropylène, un composé allylépoxyde, un composé du styrène et un initiateur du type peroxyde, les réactifs étant chauffés à une température supérieure au point de fusion du polymère polypropylène et à la température de décomposition dudit peroxyde, et mélangés simultanément d'une manière intime et continue; (ii) à introduire un polybutylène-téréphtalate dans une seconde zone d'alimentation de l'extrudeuse en aval de la première, en un point où ledit polymère polypropylène de l'étape (i) est à l'état fondu, pour assurer la fusion dudit polybutylène-téréphtalate et son mélange intime avec ladite résine polypropylène fondue; et (iii) à extruder le mélange obtenu. On obtient par ce procédé un mélange de polypropylène et de polybutylène-téréphtalate mutuellement compatibles, dans lequel les deux polymères ont un effet synergique. Le mélange obtenu peut être utilisé comme plastique industriel pour la fabrication d'articles à usage technique.
EP94930367A 1994-08-26 1994-08-26 Melanges polymeres a base de resines polypropylene et polybutylene-terephtalate Withdrawn EP0783538A1 (fr)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
BR9408611A BR9408611A (pt) 1994-08-26 1994-08-26 Processo de produzir uma mistura compatibilizada no local de polimeros de polipropileno e tereftalato de polibutileno e a respectiva mistura compatibilizada obtida
PCT/NO1994/000139 WO1996006871A1 (fr) 1994-08-26 1994-08-26 Melanges polymeres a base de resines polypropylene et polybutylene-terephtalate

Publications (1)

Publication Number Publication Date
EP0783538A1 true EP0783538A1 (fr) 1997-07-16

Family

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Family Applications (1)

Application Number Title Priority Date Filing Date
EP94930367A Withdrawn EP0783538A1 (fr) 1994-08-26 1994-08-26 Melanges polymeres a base de resines polypropylene et polybutylene-terephtalate

Country Status (3)

Country Link
EP (1) EP0783538A1 (fr)
BR (1) BR9408611A (fr)
WO (1) WO1996006871A1 (fr)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN1065888C (zh) * 1998-12-25 2001-05-16 清华大学 添加多官能单体对聚丙烯共混物反应增容的方法

Families Citing this family (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
NO975310D0 (no) * 1997-11-19 1997-11-19 Borealis As Fremgangsmåte for fremstilling av polymerblandinger basert på polyolefin og polyamid
CN101838443B (zh) * 2010-02-11 2012-06-27 国家复合改性聚合物材料工程技术研究中心 一种界面相容性良好的pbt/asa合金及其制备方法
US11236180B2 (en) * 2017-08-24 2022-02-01 Nouryon Chemicals International B.V. Process for producing high melt strength polypropylene
CN112341765B (zh) * 2020-10-29 2023-08-29 天津金发新材料有限公司 一种pbt/pp复合材料及其制备方法和应用
CN114085503B (zh) * 2021-12-23 2023-07-04 上海日之升科技有限公司 一种具有低达因值的pet树脂及其制备方法

Family Cites Families (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4981896A (en) * 1988-03-31 1991-01-01 Sumitomo Chemical Company Thermoplastic resin composition
EP0510206A4 (en) * 1990-11-02 1992-12-02 Sumitomo Chemical Company Limited Modified propylene polymer and thermoplastic resin composition comprising modified propylene polymer and polyphenylene ether

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
See references of WO9606871A1 *

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN1065888C (zh) * 1998-12-25 2001-05-16 清华大学 添加多官能单体对聚丙烯共混物反应增容的方法

Also Published As

Publication number Publication date
BR9408611A (pt) 1997-08-19
WO1996006871A1 (fr) 1996-03-07

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