EP1214356A1 - Procedes pour la preparation de compositions de nanocomposites de polyamide par polymerisation in situ - Google Patents

Procedes pour la preparation de compositions de nanocomposites de polyamide par polymerisation in situ

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Publication number
EP1214356A1
EP1214356A1 EP99942189A EP99942189A EP1214356A1 EP 1214356 A1 EP1214356 A1 EP 1214356A1 EP 99942189 A EP99942189 A EP 99942189A EP 99942189 A EP99942189 A EP 99942189A EP 1214356 A1 EP1214356 A1 EP 1214356A1
Authority
EP
European Patent Office
Prior art keywords
nylon
polyamide
silicate
clay
silicate material
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Withdrawn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
EP99942189A
Other languages
German (de)
English (en)
Inventor
Lloyd A. Goettler
Saikat S. Joardar
Bruce A. Lysek
John C. Middleton
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.)
Solutia Inc
Original Assignee
Solutia Inc
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Filing date
Publication date
Application filed by Solutia Inc filed Critical Solutia Inc
Publication of EP1214356A1 publication Critical patent/EP1214356A1/fr
Withdrawn legal-status Critical Current

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Classifications

    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08G—MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS
    • C08G69/00—Macromolecular compounds obtained by reactions forming a carboxylic amide link in the main chain of the macromolecule
    • C08G69/02—Polyamides derived from amino-carboxylic acids or from polyamines and polycarboxylic acids
    • C08G69/26—Polyamides derived from amino-carboxylic acids or from polyamines and polycarboxylic acids derived from polyamines and polycarboxylic acids
    • C08G69/28—Preparatory processes
    • 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
    • C08F2/00—Processes of polymerisation
    • C08F2/44—Polymerisation in the presence of compounding ingredients, e.g. plasticisers, dyestuffs, fillers
    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08G—MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS
    • C08G69/00—Macromolecular compounds obtained by reactions forming a carboxylic amide link in the main chain of the macromolecule
    • C08G69/02—Polyamides derived from amino-carboxylic acids or from polyamines and polycarboxylic acids
    • C08G69/04—Preparatory processes
    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08G—MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS
    • C08G69/00—Macromolecular compounds obtained by reactions forming a carboxylic amide link in the main chain of the macromolecule
    • C08G69/02—Polyamides derived from amino-carboxylic acids or from polyamines and polycarboxylic acids
    • C08G69/08—Polyamides derived from amino-carboxylic acids or from polyamines and polycarboxylic acids derived from amino-carboxylic acids
    • C08G69/14—Lactams
    • C08G69/16—Preparatory processes
    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08K—Use of inorganic or non-macromolecular organic substances as compounding ingredients
    • C08K9/00—Use of pretreated ingredients
    • C08K9/08—Ingredients agglomerated by treatment with a binding agent

Definitions

  • This invention relates to a nanocomposite material comprising a polyamide matrix having dispersed therein a treated silicate. More particularly, this invention relates to a nanocomposite material having dispersed therein a silicate material treated with at least one ammonium ion.
  • the layered material is compatibilized with one or more "effective swelling/compatibilizing agents" selected from primary ammonium, secondary ammonium and quaternary phosphonium ions.
  • the selected swelling/compatibilizing agents “...render their surfaces more organophilic than those compatibilized by tertiary and quaternary ammonium ion complexes", facilitate exfoliation, resulting in less shear in mixing and less decomposition of the polymer, and heat stabilize the composite more than other cations (such as quaternary ammonium cation ) swelling/compatibilizing agents.
  • WO 94/22430 discloses a nanocomposite composition having a polymer matrix comprising at least one gamma phase polyamide, and dispersed in the polyamide is a matrix of a nanometer-scale particulate material.
  • the addition of the particulate material to nylon 6 resulted in an improvement of flexural modulus and flexural strength (from 7 to 35%), when compared to. unfilled nylon 6.
  • the addition of the particulate material to nylon 6,6 resulted in very little improvement (1 to 3%) of flexural modulus and flexural strength when compared to unfilled nylon 6,6.
  • International Patent Application WO 95/14733 discloses a method of producing a polymer composite that does not demonstrate melting or glass transition by melt-processing a polymer with a layered gallery-containing crystalline silicate.
  • the examples include intercalated sodium silicate and a crystalline poly (ethylene oxide), montmorillonite intercalated with a quaternary ammonium and polystyrene, and montmorillonite intercalated with a quaternary ammonium and nylon 6.
  • This invention relates to a polymer nanocomposite composition suitable for automotive, electronic, film and fiber applications, where a combination of tensile strength, tensile modulus and flexural modulus are required. Additionally, the claimed polymer nanocomposite composition also has a desirable surface appearance, toughness, ductility and dimensional -In ⁇
  • composition processes well and tolerates a wide range of molding conditions.
  • Such polymer nanocomposite composition comprises a polyamide and a treated silicate, wherein the treated silicate includes a silicate material treated with at least one ammonium ion of the formula:
  • Ri, 2 f R3 and R 4 are independently selected from a group consisting of a saturated or unsaturated Ci to C 22 hydrocarbon, substituted hydrocarbon and branched hydrocarbon, or where Ri and R 2 form a N,N-cyclic ether.
  • Examples include saturated or unsaturated alkyls, including alkylenes; substituted alkyls such as hydroxyalkyls, alkoxyalkyls, alkoxys, amino alkyls, acid alkyls, halogenated alkyls, sulfonated alkyls, nitrated alkyls and the like; branched alkyls; aryls and substituted aryls, such as alkylaryls, alkyoxyaryls, alkylhydroxyaryls, alkylalkoxyaryls and the like.
  • one of Ri, R 2 , R 3 and R 4 is hydrogen.
  • the milligrams of treatment per 100 grams of silicate (MER) of the treated silicate is from about 10 milliequivalents/100 g below the cation exchange capacity of the untreated silicate to about 30 milliequivalents/100 g above the cation exchange capacity of the untreated silicate.
  • the composite polymer matrix material demonstrates, when tested, an improvement in tensile modulus and flexural modulus, without a substantial decrease in tensile strength, when compared to that of the polymer without the treated silicate.
  • substantially decrease means a decrease exceeding the statistically determined deviations.
  • the present invention further relates to a process to prepare the above polymer nanocomposite composition
  • a process to prepare the above polymer nanocomposite composition comprising forming a flowable mixture of a polyamide and a treated silicate material and dissociating (as that term is described in more detail below) at least about 50% but not all of the treated silicate.
  • the treated silicate is a silicate material treated with at least one ammonium ion of the formula: + NR ⁇ R 2 R 3 R 4 wherein:
  • Ri, R 2 , R 3 and R 4 are independently selected from a group consisting of a saturated or unsaturated Ci to C 22 hydrocarbon, substituted hydrocarbon and branched hydrocarbon, or where Ri and R 2 form a N,N-cyclic ether.
  • Examples include saturated or unsaturated alkyls, including alkylenes; substituted alkyls such as hydroxyalkyls, alkoxyalkyls, alkoxys, amino alkyls, acid alkyls, halogenated alkyls, sulfonated alkyls, nitrated alkyls and the like; branched alkyls; aryls and substituted aryls, such as alkylaryls, alkyoxyaryls, alkylhydroxyaryls, alkylalkoxyaryls and the like.
  • one of Ri, R 2 , R 3 and R is hydrogen.
  • the milligrams of treatment per 100 grams of silicate (MER) of the treated silicate is from about 10 milliequivalents/100 g below the cation exchange capacity of the untreated silicate to about 30 milliequivalents/100 g above the cation exchange capacity of the untreated silicate.
  • the composite polymer matrix material demonstrates, when tested, an improvement in tensile modulus and flexural modulus, without a significant decrease in tensile strength, when compared to that of the polymer without the treated silicate.
  • Polyamides of the present invention are synthetic linear polycarbonamides characterized by the presence of recurring carbonamide groups as an integral part of the polymer chain which are separated from one another by at least two carbon atoms.
  • Polyamides of this type include polymers, generally known in the art as nylons, which can be obtained from diamines and dibasic acids having the recurring unit represented by the general formula:
  • R5 is an alkylene group of at least 2 carbon atoms, preferably from about 2 to about 11 or arylene having at least about 6 carbon atoms, preferably about 6 to about 17 carbon atoms; and Re is selected from R5 and aryl groups.
  • copolyamides, terpolyamides and the like obtained by known methods, for example, by condensation of hexamethylene diamine and a mixture of dibasic acids consisting of terephthalic acid and adipic acid.
  • Polyamides of the above description are well-known in the art and include, for example, poly (hexamethylene adipamide) (nylon 6,6), poly (hexamethylene sebacamide) (nylon 6,10), poly (hexamethylene isophthalamide) , poly (hexamethylene terephthalamide) , poly (heptamethylene pimelamide) (nylon 7,7), poly (octamethylene suberamide) (nylon 8,8), poly (nonamethylene azelamide) (nylon 9,9), poly (decamethylene sebacamide) (nylon 10,9), poly (decamethylene sebacamide) (nylon 10,10), poly [bis (4-amino cyclohexyl) methane-
  • polystyrene carboxylate 1, 10-decanecarboxamide) ] , poly (m-xylene adipamide), poly (p-xylene sebacamide), poly (2, 2, 2-trimethyl hexamethylene terephthalamide), poly (piperazine sebacamide), poly (p-phenylene terephthalamide), poly (metaphenylene isophthalamide), and copolymers and terpolymers of the above polymers.
  • Additional polyamides include nylon 4,6, nylon 6,9, nylon 6,10, nylon 6,12, nylon 11, nylon 12, amorphous nylons, aromatic nylons and their copolymers.
  • Other useful polyamides are those formed by polymerization of amino acids and derivatives thereof, as for example, lactams.
  • Illustrative of these useful polyamides are poly (caprolactam) (nylon 6), poly (4-aminobutyric acid) (nylon 4), poly(7- aminoheptanoic acid) (nylon 7), poly (8-aminooctanoic acid) (nylon 8), poly (9-aminononanoic acid) (nylon 9), poly (10-aminodecanoic acid) (nylon 10), poly (11-aminoundecanoic acid) (nylon 11), poly (12-aminodocecanoic acid) (nylon 12) and the like.
  • the preferred polyamide is Vydyne ⁇ nylon, which is poly (hexamethylene adipamide) (nylon 6,6), which gives a composite with the desired combination of tensile strength, tensile modulus and flexural modulus for the applications contemplated herein (Vydyne® is a registered trademark of Solutia, Inc. ) .
  • the preferred molecular weight of the polyamide is in the range of 30,000 to 80,000 D (weight average) with a more preferred molecular weight of at least 40,000 D (weight average).
  • Increasing the weight average molecular weight of the polyamide from about 35,000 to 55,000 D results in an unexpected increase in toughness as indicated by the notched izod impact test.
  • an increase in the weight average molecular weight of from about 35,000 to 55,000 D in the polyamide neat results in a small increase in toughness
  • the same increase in molecular weight in the nanocomposite results about twice the increase in toughness. Therefore, the increase in toughness is enhanced in the nanocomposite when compared to that of the polyamide neat.
  • the polyamide has an amine end group/acid end group ratio greater than one (1) . More preferably, the concentration of amine end groups is at least 10 mole % greater than the concentration of the carboxylic acid end groups. In an even more preferred embodiment, the polyamide has a concentration of amine end groups at least 20 mole % greater than the concentration of the carboxylic acid end groups, and in a most preferred embodiment, the polyamide has a concentration of amine end groups at least 30 mole % greater than the concentration of the carboxylic acid end groups. In another embodiment, the concentration of amine end groups is essentially equal to the concentration of carboxylic acid end groups. Among the preferred embodiments is nylon 6, nylon 6,6, blends thereof and copolymers thereof.
  • the range of ratios of the nylon 6/nylon 6,6 in the blends is from about 1/100 to 100/1. Preferably, the range is from about 1/10 to 10/1.
  • the range of ratios of the nylon 6/nylon 6,6 in the copolymers is about 1/100 to 100/1. Preferably, the range is from about 1/10 to 10/1.
  • the nanocomposite composition comprises at least one additional polymer.
  • suitable polymers include polyethyleneoxide, polycarbonate, polyethylene, polypropylene, poly (styrene-acrylonitrile) , poly (acrylonitrile- butadiene-styrene) , poly (ethylene terephthalate), poly (butylene terephthalate), poly (trimethylene terephthalate), poly (ethylene naphthalate) , poly (ethylene terephthalate-co-cyclohexane dimethanol terephthalate), polysulphone, poly (phenylene oxide) or poly (phenylene ether), poly (hydroxybenzoic acid-co-ethylene terephthalate), poly (hydroxybenzoic acid-co-hydroxynaphthenic acid), poly (esteramide) , poly (etherimide) , poly (phenylene sulfide) , poly (phenylene terephthalamide).
  • the mixture may include various optional components which are additives commonly employed with polymers.
  • Such optional components include surfactants, nucleating agents, coupling agents, fillers, impact modifiers, chain extenders, plasticizers, compatibilizers, colorants, mold release lubricants, antistatic agents, pigments, fire retardants, and the like.
  • Suitable examples of fillers include carbon fiber, glass fiber, kaolin clay, wollastonite and talc.
  • Suitable examples of compatibilizers include acid-modified hydrocarbon polymer, such as maleic anhydride-grafted propylethylene, maleic anhydride- grafted polypropylene, maleic anhydride-grafted ethylenebutylene- styrene block copolymer.
  • Suitable examples of mold release lubricant includes alkyl amine, stearamide, and di-or tri- aluminum stearate.
  • Suitable examples of impact modifiers include ethylene- propylene rubber, ethylene-propylene diene rubber, methacrylate- butadiene-styrene (with core-shell morphology) , poly (butylacrylate) with or without carboxyl modification, poly (ethylene acrylate) , pol (ethylene methylacrylate) , poly (ethylene acrylic acid), poly (ethylene acrylate) ionomers, poly (ethylene methacrylate acrylic acid) terpolymer, poly (styrene-butadiene) block copolymers, poly (styrene-butadiene- styrene) block terpolymers, poly (styrene-ethylene/butylene- styrene) block terpolymers and poly (styrene-ethylene/butylene- styrene
  • Silane coupling agents are well-known in the art and are useful in the present invention.
  • suitable coupling agents include octadecyltrimethoxysilane, gamma- aminopropyltriethoxysilane, gamma-aminopropyltrimethoxysilane, gamma-aminopropylphenyldimethoxysilane, gamma-glycidoxypropyl tripropoxysilane, 3, 3-epoxycyclohexylethyl trimethoxysilane, gamma-proprionamido trithoxysilane, N-trimethoxysilylpropyl- N (beta-aminoethyl) amine, trimethoxysilylundecylamine, trimethoxysilyl-2-chloromethylphenylethane, trimethoxysilylethylphenylsulfonylazide, N-trimethoxysilyl
  • the preferred silane is gamma-aminopropyltriethoxysilane .
  • the silane coupling agent is optionally added to the polymer composite in the range of about 0.5 to 5 weight % of the layered silicate.
  • the preferred concentration range of silane coupling agent is about 1 to 3 weight % of the layered silicate in the composite .
  • the nanocomposite composition further comprises a composition wherein an acid end group of the polyamide is bonded to a surface of the treated layered silicate by a silane coupling agent.
  • the silicate materials of the present invention are selected from the group consisting of layered silicates and fibrous, chain-like silicates, and include phyllosilicates.
  • fibrous, chain-like silicates include chain-like minerals, for example sepiolite and attapulgite, with sepiolite being preferred.
  • Such silicates are described, for example, in Japanese Patent Application Kokoku 6-84435 published October 26, 1994.
  • layered silicates include layered smectite clay minerals such as montmorillonite, nontronite, beidellite, volkonskoite, Laponite® synthetic hectorite, natural hectorite, saponite, sauconite, magadiite, and kenyaite; vermiculite; and the like.
  • Other useful materials include layered illite minerals such as ledikite and admixtures of illites with one or more of the clay minerals named above.
  • the preferred layered silicates are the smectite clay minerals such as montmorillonite, nontronite, beidellite, volkonskoite, Laponite® synthetic hectorite, natural hectorite, saponite, sauconite, magadite, and kenyaite.
  • layered silicate materials suitable for use in the present invention are well-known in the art, and are sometimes referred to as "swellable layered material". A further description of the claimed layered silicates and the platelets formed when melt processed with the polyamide is found in
  • the layered silicate materials typically have planar layers arrayed in a coherent, coplanar structure, where the bonding within the layers is stronger than the bonding between the layers such that the materials exhibit increased interlayer spacing when treated.
  • the layered silicate materials require treatment as described in more detail below with the subject ammonium ion to provide the interlayer swelling and/or spacing required for the performance of the treated silicate of the present invention.
  • inter layer spacing refers to the distance between the faces of the layers as they are assembled in the treated material before any delamination (or exfoliation) takes place.
  • the preferred clay materials generally include interlayer or exchangeable cations such as Li + , Na + , Ca +2 , K + , Mg +2 and the like. In this state, these materials have interlayer spacings usually equal to or less than about 4 A and only delaminate to a low extent in host polymer melts regardless of mixing.
  • the cationic treatment is a ammonium species which is capable of exchanging with the interlayer cations such as Li + , Na + , Ca +2 , K + , Mg +2 and the like in order to improve delamination of the layered silicate.
  • the treated silicate of the present invention is a silicate material as described above which is treated with at least one ammonium ion of the formula
  • Ri, R 2 , R 3 and R 4 are independently selected from a group consisting of a saturated or unsaturated Ci to C 22 hydrocarbon, substituted hydrocarbon and branched hydrocarbon, or where Ri and R 2 form a N,N-cyclic ether.
  • Examples include saturated or unsaturated alkyls, including alkylenes; substituted alkyls such as hydroxyalkyls, alkoxyalkyls, alkoxys, amino alkyls, acid alkyls, halogenated alkyls, sulfonated alkyls, nitrated alkyls and the like; branched alkyls; aryls and substituted aryls, such as alkylaryls, alkyoxyaryls, alkylhydroxyaryls, alkylalkoxyaryls and the like.
  • one of Ri, R 2 , R 3 and R 4 is hydrogen.
  • a mixture of two or more ammonium ions is contemplated by the present invention.
  • Ri is selected from the group consisting of hydrogenated tallow, unsaturated tallow or a hydrocarbon having at least 6 carbons, and R 2 , R 3 and R independently have from one to eighteen carbons.
  • Tallow is composed predominantly of octadecyl chains with small amounts of lower homologues, with an average of from 1 to 2 degrees of unsaturation.
  • the approximate composition is 70% Cis, 25% Ci6, 4% C14 and 1% C ⁇ 2 .
  • Ri and R 2 are independently selected from the group consisting of hydrogenated tallow, unsaturated tallow or a hydrocarbon having at least 6 carbons and R 3 and R 4 independently have from one to twelve carbons.
  • Ri, R 2 , R 3 and R 4 groups are alkyl such as methyl, ethyl, octyl, nonyl, tert-butyl, ethylhexyl, neopentyl, isopropyl, sec-butyl, dodecyl and the like; alkenyl such as 1-propenyl, 1-butenyl, 1-pentenyl, 1-hexenyl, 1-heptenyl, 1-octenyl and the like; cycloalkyl such as cyclohexyl, cyclopentyl, cyclooctyl, cycloheptyl and the like; alkoxy such as ethoxy; hydroxyalkyl; alkoxyalkyl such as methoxymethyl, ethoxymethyl, butoxymethyl, propoxyethyl, pentoxybutyl and the like; aryloxyalkyl and aryloxyaryl such as phenoxyphen
  • the preferred ammoniums used in treating the silicate materials include oniums such as dimethyldi (hydrogenated tallow) ammonium, dimethylbenzyl hydrogenated tallow ammonium, dimethyl (ethylhexyl) hydrogenated tallow ammonium, trimethyl hydrogenated tallow ammonium, methylbenzyldi (hydrogenated tallow) ammonium, N, N-2-cyclobutoxydi (hydrogenated tallow) ammonium, trimethyl tallow ammonium, methyldihydroxyethyl tallow ammonium, octadecylmethyldihydroxyethyl ammonium, dimethyl (ethylhexyl) hydrogenated tallow ammonium and mixtures thereof.
  • oniums such as dimethyldi (hydrogenated tallow) ammonium, dimethylbenzyl hydrogenated tallow ammonium, dimethyl (ethylhexyl) hydrogenated tallow ammonium, trimethyl
  • ammoniums include quaternary ammoniums, for example, dimethyldi (hydrogenated tallow) ammonium, dimethylbenzyl hydrogenated tallow ammonium, methyldihydroxyethyl tallow ammonium, octadecylmethyldihydroxyethyl ammonium, dimethyl (ethylhexyl) hydrogenated tallow ammonium and mixtures thereof.
  • quaternary ammoniums for example, dimethyldi (hydrogenated tallow) ammonium, dimethylbenzyl hydrogenated tallow ammonium, methyldihydroxyethyl tallow ammonium, octadecylmethyldihydroxyethyl ammonium, dimethyl (ethylhexyl) hydrogenated tallow ammonium and mixtures thereof.
  • the treatment with the ammonium ion(s), also called “cationic treatments”, may include introduction of the ions into the silicate material by ion exchange.
  • the cationic treatments may be introduced into the spaces between every layer, nearly every layer, or a large fraction of the layers of the layered material such that the resulting platelet layers comprise less than about 20 particles in thickness.
  • the platelet layers are preferably less than about 8 particles in thickness, more preferably less than about 5 particles in thickness, and most preferably, about 1 or 2 particles in thickness.
  • the treated silicate has a MER of from about 10 milliequivalents/100 g below the cation exchange capacity of the untreated silicate to about 30 milliequivalents/100 g above the cation exchange capacity of the untreated silicate.
  • the MER is the milliequivalents of treatment per 100 g of silicate.
  • Each untreated silicate has a cation exchange capacity, which is the milliequivalents of cations available for exchange per 100 g of silicate.
  • the cation exchange capacity of the layered silicate montmorillonite can be about 95, and the exchange capacity of sepiolite is in the range of about 25 to 40.
  • a first nanocomposite sample may have a higher concentration of treated silicate but a lower concentration of silicate, than a second nanocomposite sample, because the first sample has a higher MER than the second sample.
  • the MER value of the treated silicate is substantially less than its exchange capacity, for example about 85 MER for the preferred montmorillonite, there is too little of the cationic treatment to have a beneficial effect. If the MER exceeds about 125, the excess ammonium may be detrimental to the properties of the nylon.
  • the untreated montmorillonite has an exchange capacity of 95
  • the treated layered silicate has a cation exchange capacity of from about 85 to about 125.
  • the amount of treated silicate included in the composition is in the range of about 0.1 to 12 weight % of the composite.
  • the concentration is adjusted to provide a composite polymer matrix material which demonstrates, when tested, an increase in tensile modulus and flexural modulus, without a decrease in tensile strength.
  • the increase in tensile modulus and flexural modulus is at least about 10%. More preferably, the increase in tensile modulus and flexural modulus is at least about 20%. Too little treated silicate fails to provide the desired increase in tensile modulus and flexural modulus. Too much treated silicate provides a polyamide composite with a decreased tensile strength. Further, it may be desirable to have the crystalline regions of the polyamide in the nanocomposite composition be less than l.O ⁇ m.
  • the particle size of the treated silicate is such that optimal contact between the polymer and the treated silicate is facilitated.
  • the range of particle size can vary from about 10 microns to about 100 microns.
  • the particle size is in the range of from about 20 to 80 microns.
  • the particle size is below about 30 microns, such as those that pass through 450 mesh screens, in that the resulting polymer nanocomposite has improved performance properties.
  • the silicate can be treated with a mixture of one or more quaternary ammonium ions with one or more ammonium ions of the formula
  • R a , Rb and R c is hydrogen (H) and Rd is selected from a group consisting of a saturated or unsaturated Ci to C 22 hydrocarbon, substituted hydrocarbon and branched hydrocarbon.
  • Examples include saturated or unsaturated alkyls, including alkylenes; substituted alkyls such as hydroxyalkyls, alkoxyalkyls, alkoxys, amino alkyls, acid alkyls, halogenated alkyls, sulfonated alkyls, nitrated alkyls and the like; branched alkyls; aryls and substituted aryls, such as alkylaryls, alkyoxyaryls, alkylhydroxyaryls, alkylalkoxyaryls and the like.
  • the Rd group for the ammonium ion above is generally the same as the definition for the R 4 group in the ammonium ion, which in this embodiment is a quaternary ammonium, the Examples set forth above for the R 4 group are also exemplary of the Rd group.
  • the Rd group further contains a carboxylic acid moiety such that the ammonium ion
  • NR a RbRcRd is an amino acid, for example 12-aminolauric acid ammonium.
  • the amine end groups/acid end groups ratio of the polyamide is greater than one
  • a preferred mixture includes at least one of dimethyldi (hydrogenated tallow) ammonium, methyl dihydroxyethyl tallow ammonium and/or dimethyl (ethylhexyl) hydrogenated tallow ammonium, either alone or in combination with 12-aminolauric acid ammonium.
  • the treated silicate can be further treated with azine cationic dyes, such as nigrosines or anthracines.
  • Said cationic dyes would impart color-fastness and uniformity of color in addition to increasing the intercalation of the polymer molecules .
  • the preferred nanocomposite contains a concentration of treated silicate of from about 0.1 to about 12.0 weight % of the composite.
  • the most preferred nanocomposite contains a concentration of treated silicate of from about 0.5 to about 6.0 weight % of the composite.
  • the nanocomposite composition is prepared using a two step process.
  • One step includes forming a flowable mixture of the polyamide as a polymer melt and the treated silicate material.
  • the other step includes dissociating at least 50% but not all of the treated silicate material.
  • the term "dissociating", as utilized herein, means delaminating or separating treated silicate material into submicron-scale structures comprising individual or small multiple units.
  • this dissociating step includes delaminating the treated silicate material into submicron scale platelets comprising individual or small multiple layers.
  • this dissociating step includes separating the treated silicate material into sub- micron scale fibrous structures comprising individual or small multiple units.
  • a flowable mixture is a mixture which is capable of dispersing dissociated treated silicate material at the submicron scale.
  • a polymer melt is a melt processable polymer or mixture of polymers which has been heated to a temperature sufficiently high to produce a viscosity low enough for submicron scale mixing to occur.
  • the process temperature should be at least as high as the melting point of the polyamide employed and below the degradation temperature of the polyamide and of the organic treatment of the silicate.
  • the actual extruder temperature may be below the melting point of the polyamide employed, because heat is generated by the flow.
  • the process temperature is high enough that the polymer will remain in the polymer melt during the conduct of the process.
  • a typical nylon 6, having a melting point of about 225°C can be melted in an extruder at any temperature equal to or greater than about 225°C, as for example between about 225°C and about 260°C.
  • a temperature of preferably from about 260°C to about 320°C is normally employed.
  • the flowable mixture can be prepared through use of conventional polymer and additive blending means, in which the polymer is heated to a temperature sufficient to form a polymer melt and combined with the desired amount of the treated silicate material in a granulated or powdered form in a suitable mixer, as for example an extruder, a Banbury® type mixer, a Brabender® type mixer, Farrel® continuous mixers, and the like.
  • a suitable mixer as for example an extruder, a Banbury® type mixer, a Brabender® type mixer, Farrel® continuous mixers, and the like.
  • the flowable mixture may be formed by mixing the polyamide with a previously formed treated silicate- containing concentrate.
  • the concentrate includes the treated silicate and a polymer carrier.
  • the concentration of the treated silicate material in the concentrate is selected to provide the desired treated silicate concentration for the final nanocomposite composition.
  • suitable polymers for the carrier polymer of the concentrate include polyamide, ethylene propylene rubber, ethylene propylene diene rubber, ethylene- ethylacrylate, ethylene-ethylmethacrylate or ethylene methacrylate. Examples include Iotek® ionomer and Escor® ATX acid terpolymer, both available from Exxon.
  • the polyamide polymers suitable for the carrier polymer include nylons such as nylon 6, nylon 6,6, nylon 4,6, nylon 6,9, nylon 6,10, nylon 6,12, nylon 11, nylon 12, amorphous nylons, aromatic nylons and their copolymers.
  • the polymer of the carrier may be the same as or different from the polyamide of the flowable mixture.
  • both polymers may be a polyamide, particularly nylon 6,6, but may have the same or different molecular weight.
  • the preferred weight average molecular weight of the carrier polymer of the concentrate is in the range of about 5,000 D to about 60,000 D.
  • the most preferred range of the weight average molecular weight for the carrier polymer is in the range of about 10,000 to about 40,000 D.
  • the dissociation step of the present process as described below, may occur at least in part via the forming of the concentrate such that the dissociation step may precede the step of forming the flowable mixture.
  • the process steps may occur sequentially without regard to order, simultaneously or a combination thereof.
  • the flowable mixture is sufficiently mixed to form the dispersed nanocomposite structure of dissociated silicate in the polymer melt, and it is thereafter cooled.
  • the silicate can be dissociated by being subjected to a shear having an effective shear rate.
  • an effective shear rate is a shear rate which is effective to aid in dissociation of the silicate and provide a composition comprising a polyamide matrix having silicate substantially homogeneously dispersed therein without substantially breaking the individual units (e.g., platelets or fibrous chains) .
  • any method which can be used to apply a shear to a flowable mixture or any polymer melt can be used.
  • the shearing action can be provided by any appropriate method, such as by mechanical means, by thermal shock, by pressure alteration, or by ultrasonics.
  • the flowable polymer mixture is sheared by mechanical methods in which portions of the melt are caused to flow past other portions of the mixture by use of mechanical means such as stirrers, Banbury® type mixers, Brabender® type mixers, Farrel® continuous mixers, and extruders.
  • the mixture is subjected to multiple shearings.
  • increased residence time is also provided, which results in improved performance properties.
  • shearing is achieved by alternatively raising or lowering the temperature of the mixture causing thermal expansions and resulting in internal stresses which cause the shear.
  • shear is achieved by sudden pressure changes in pressure alteration methods; by ultrasonic techniques in which cavitation or resonant vibrations which cause portions of the mixture to vibrate or to be excited at different phases and thus subjected to shear.
  • Shearing can be achieved by introducing the polymer pellets -at one end of the extruder (single or twin screw) and receiving the sheared polymer at the other end of the extruder.
  • a preferred twin screw extruder is a co-rotating fully intermeshing type, such as the ZSK series manufactured by Werner and Pfleiderer Company.
  • the layered silicate can be fed into the twin screw extruder at the feed throat or at the downstream vent.
  • the preferred method is to feed the layered silicate at the downstream vent, which produces a composite polymer with improved performance properties.
  • an additional processing step can be added, such as solid state polymerization, wherein the compounded pellets are held for several hours at a high temperature below the melting point of the polymer.
  • typical solid state polymerization conditions are heating the solid polymer in the range of about 200 to 240°C for a period of from about two (2) to five (5) hours.
  • Said additional processing step results in an increase in molecular weight and an improvement in toughness, ductility and tensile strength of the nanocomposite.
  • Another optional processing step can be a heat treatment step, where the composition is heated to improve intercalation of the nylon molecules into the silicate structure.
  • Said heat treatment step is performed by heating the composition at a temperature in the range of about 200 to 240°C for a period of about two (2) to five (5) hours.
  • FCM Farrel Continuous Mixer
  • the polymer melt containing nano-dispersed dissociated silicate material may also be formed by reactive extrusion in which the silicate material is initially dispersed as aggregates or at the nanoscale in a liquid or solid monomer and this monomer is subsequently polymerized in an extruder or the like.
  • the polymer may be granulated and dry mixed with the treated silicate material, and thereafter, the composition may be heated in a mixer until the polymer is melted forming the flowable mixture.
  • the process to form the nanocomposite is preferably carried out in the absence of air, as for example in the presence of an inert gas, such as argon, neon or nitrogen.
  • the process can be carried out in a batchwise or discontinuous fashion, as for example, carrying out the process in a sealed container.
  • the process can be carried out in a continuous fashion in a single processing zone, as for example, by use of an extruder, from which air is largely excluded, or in a plurality of such reaction zones in series or in parallel.
  • the process to prepare a polymer nanocomposite composition comprises forming a first flowable mixture of a polyamide, at least one monomer, and a treated silicate material; dissociating at least
  • At least one monomer of the third embodiment includes monomers such as ⁇ - caprolactam, lauryllactam, and their corresponding lactones.
  • the process to prepare a polymer nanocomposite composition comprises forming a flowable mixture of a polyamide and a treated silicate material; dissociating the at least about 50% but not all of the treated silicate material; and adding an additional amount of said polyamide, most preferably during said dissociating step.
  • composition of the present invention can be made into, but is not limited to, the form of a fiber, film or a molded article. Examples The following examples are presented to further illustrate the invention and do not limit the scope of the claims in any manner. All of the nylons used in the following examples are nylon 6,6. Unless otherwise indicated, the nylon used was nylon h, manufactured by Solutia, Inc, and characterized in the Table of Nylon Types, below. Unless otherwise indicated, all percents are weight percent.
  • the % clay is the total weight of pristine clay in the final composite, be it pristine or pre-treated.
  • Tensile strength and Young's Modulus are measured according to ASTM method D638 and are reported in kpsi and MPa.
  • Flexural modulus is measured according to ASTM method D790 and is reported in kpsi and MPa.
  • the runs numbered with a "-C" are control runs.
  • R octadecylmethyldiethoxy 95 S trimethyl C 22 110 T dimethyldi (hydrogenated tallow), better dispersing form 95 U dimethyldi (hydrogenated tallow), processed 95 V item U, above, with 1% surfactant 95
  • Items GG through NN are examples of montmorillonite, unless otherwise indicated, treated with the blends of more than one quaternary ammonium or of a quaternary ammonium and ammonium of the present invention.
  • Items 00 through TT are examples of the tertiary ammonium silicates of the present invention.
  • KK 10.5/89.5 blend of 12-aminolauric acid and dimethydi (hydrogenated tallow) 95 LL 16/84 blend of 12-aminolauric acid and dimethydi (hydrogenated tallow), 95
  • the amine ends and the acid ends are the equivalents of unreacted amine and acid functional groups on the nylon.
  • the M w is the weight average molecular weight as measured in Daltons.
  • Table 1 composites of four (4) different types of treated clay are shown.
  • the control examples using clays not treated with ammoniums of the present invention show a general decrease in tensile strength when compared to the preceding (i.e. comparable) sample containing no clay (i.e., comparing 2-C, 3-C and 4-C to 1-C and comparing 6-C, 7-C and 8-C to 5-C) , with the exception of control example 3-C which shows no change in tensile strength when compared to 1-C.
  • Runs 1-C through 4-C were processed with a ZSK twin screw extruder, and runs 5-C through 8-C were processed with a FCM mixer.
  • nylon 6,6 products were used to prepare composites: nylon d, nylon c, nylon b, nylon h, shown in the Table of Nylon Types.
  • the nylons are presented above in order of decreasing average molecular weight.
  • the composites were processed using a ZSK twin screw extruder.
  • All composites show an increase in tensile modulus and flexural modulus without a decrease in tensile strength when compared to samples without treated clay.
  • the weight ratio of nylon blend h/b was 70/30.
  • the other polymer used was Iotek 971 ionomer.
  • the other polymer used was ATX 320 acid terpolymer.
  • the runs in Table 8 vary the feed points for processing the nylon with the treated clay.
  • the clay was fed into the ZSK twin screw extruder at the throat or downstream of the throat.
  • the nylon used was a copolymer of 80% nylon 6,6 and 20% nylon 6.
  • composites are prepared from eight (8) different quaternary ammonium/ammonium blend-treated silicates.
  • the composites are processed using a ZSK twin screw extruder. Taking into account the standard deviations of the tensile strength measurements, all of the samples show an increase in tensile modulus and flex modulus without a decrease in tensile strength. Samples 125 through 135 show the effect of varying the nylon type.
  • composites are prepared from six (6) different tertiary ammonium-treated silicates.
  • the composites are processed using a ZSK twin screw extruder. Taking into effect the standard deviation of the tensile strength measurements, all of the samples show an increase in tensile modulus and flex modulus without a decrease in tensile strength
  • In-situ polymerization holds great promise for improving clay dispersion and enhancing the strength of the silicate-nylon interface over that obtained by melt compounding. Efficient reinforcement comprising more than 20% increase in modulus has been found for a nanocomposite containing only 0.1% by weight nano-silicate. Silane may be added to the reactor feed to improve interfacial bonding in the final nanocomposite.
  • Polyamide nanocomposite compositions may be formed by a process comprising forming an aqueous mixture of a treated silicate material and a polyamide monomer, treating the mixture to polymerize the polyamide monomer, and dissociating at least about 50% of the silicate material to form a polyamide nanocomposite composition.
  • layered (montmorillonite, saponite, hectorite, laponite) and chain- like (sepiolite) silicates may be incorporated into nylon 6,6 and nylon 6,6/6 copolymers by exfoliating and dispersing the clay in the hexamethylene adipamide (HMA) nylon 6,6 salt solution prior to polymerization.
  • Nylon 6,6/6 copolymers may be produced by including a component of epsilon-caprolactam in the monomer feed. The process has been demonstrated in both laboratory and pilot (250 pound (113 kg)) scale autoclaves.
  • the silicates may be pre-dispersed in the caprolactam component prior to its addition to the salt solution.
  • concentrates may be made in nylon 6 or in its precursor caprolactam solution, preferably with the addition of a peptizer, for later addition to the nylon 6,6 polymerization mixture.
  • Low molecular weight liquid polyamides may be used as carriers for the nanoclay. Concentrates of the nanoclay exfoliated in these carriers by high shear homogenization may be added later in the nylon 6,6 polymerization cycle after the aqueous ionic environment is driven off. The following parameters may affect the performance of the process: a.
  • a diamine spike i.e., a higher molar concentration of hexamethylene diamine (HMD) than adipic acid in the mixture to counter any acidity due to the clay or its treatment, as well as to compensate for the loss of HMD by vaporization during the polymerization cycles.
  • HMD hexamethylene diamine
  • Certain mineral types are preferable for use in the in-situ polymerization process, including synthetic Laponite, commercially available from SCP under the trade name Laponite®, hectorite, sepiolite, saponite, and montmorillonite at various points in the reaction cycle. It has been found to be preferable to first achieve a good dispersion of the exfoliated silicate layers in water prior to contact with the salt solution. In this regard it may be useful to start with a never-dried aqueous dispersion or aqueous suspension instead of dry silicate. Alternatively, dry silicate may be hydrated prior to its participation in the polymerization process. Silicate may be dispersed through high shear homogenization or cavitation generated ultrasonically or by throttling the aqueous suspension through a venturi tube or other methods known in the art.
  • the silicate material may be organically modified to produce a stronger interface with the nylon matrix phase of the final nanocomposite.
  • Such organoclays are more hydrophobic than the pristine minerals and so may not form stable colloidal dispersions in water or in the nylon 6,6 salt solution.
  • polymer can intercalate the layered clay structure later in the polymerization cycle after the aqueous phase has been largely removed by vaporization.
  • its lower molecular weight should actually enhance the rate of intercalation, leading to a more complete state of layer exfoliation and higher reinforcement of the final composite by the resulting smaller particle thicknesses than is obtained by direct melt compounding with a pre-polymerized nylon resin.
  • the silicate material may be added later in the polymerization cycle after the salt has been converted to oligomers or low molecular weight polymers.
  • An alternate approach to avoiding ionic effects is to start the process with molten anhydrous salt in place of the salt solution.
  • concentration In order to avoid gelling, it may be preferable to limit concentration to 2% or possibly up to 4% of the other minerals. Higher concentrations up to about twice these limits may be feasible when a peptizer is also present in the mixture.
  • These contain phosphate ions which may retard the buildup of structure in aqueous suspensions. The phosphates also act as buffers to control pH, which may also be desirable in achieving a high degree of clay dispersion.
  • Foaming was experienced during in-situ polymerization in a lab autoclave with tallow-based (e.g., dimethyl-dihydrogenated tallow ammonium (2M2HT)) organoclay, while untreated (pristine) sodium and calcium montmorillonites did not exfoliate, according to clumps visible by optical microscopy.
  • tallow-based e.g., dimethyl-dihydrogenated tallow ammonium (2M2HT)
  • 2M2HT dimethyl-dihydrogenated tallow ammonium
  • a 97.5/2.5 nylon 6/6,6 copolymer was polymerized in the presence of 4% by weight 12- aminolauric acid organomontmorillonite.
  • the product displayed considerably enhanced toughness and ductility over the nylon 6,6 homopolymer nanocomposite.
  • Optical microscopy indicated the absence of any micron-sized clay residue, suggesting a higher degree of clay delamination than for the earlier homopolymer. This was confirmed by transmission electron: microscopy (TEM). Injection molded properties of this sample were high, showing a 25% increase in tensile modulus and 50% increase in yield strength, with only about 1% silicate on a volume basis - a high reinforcement efficiency.
  • Alkoxy-modified organoclays comprising the more polar ammonium ions synthesized from alkoxy-functional Jeffamines were observed to produce more stable colloidal suspensions in mixed HMA/caprolactam solutions.
  • In-situ polymerization was successfully performed with an ethoxy- modified montmorillonite. Initially, temperature was kept low ( ⁇ 260°C) to safeguard against degradation of the clay coating. Smaller test tube sized polymerizations were performed without stirring in a Parr reactor over a range in ethylene oxide / propylene oxide sequencing on the ammonium cation of the treated montmorillonite. WAXS measurements showed the same degree of polymer intercalation into the silicate structure as in samples made with stirring in a lab autoclave.
  • Coating compositions allowed the nylon 6,6 content to be raised as high as 12% without obstructing the silicate intercalation.
  • One polypropylene oxide quat produced a particularly stable colloidal suspension in a 50/50 mixture of nylon 6,6 salt solution and caprolactam solution that did not phase separate for several days at room temperature.
  • pristine sodium montmorillonite suspensions were found not to be stable at room temperature across a range of HMA caprolactam mixture compositions, though in-situ polymerization of straight nylon 6 nanocomposite from caprolactam solution comprising Gelwhite pristine Ca-montmorillonite supplied by Southern Clay Products, Inc. produced a smooth- flowing concentrate that could later be let down into nylon 6,6 to form a blended nanocomposite.
  • montmorillonite when fully pre-hydrated, either as a never-dried slurry or by first completely suspending dry clay in water, it forms a more stable colloidal suspension in hexamethylene adipamide salt solution.
  • the following types were found to produce stable 3% colloidal suspensions in water following high shear mixing with an Omni homogenizer: Gelwhite H and Gelwhite L (sodium-exchanged Ca-montmorillonite), Mineral Colloid BP (pristine Na-montmorillonite), poly(propylene oxide) treated montmorillonite, and a hydroxy-terminated poly(ethylene oxide / propylene oxide) copolymer treated montmorillonite.
  • nylon 6 nanocomposites were prepared in-situ from a water solution of caprolactam containing a range of pristine nanoclays, including Ca-montmorillonite, Na-montmorillonite, laponite RD synthetic hectorite and attapulgite.
  • the laponite appeared to disperse most readily, showing no peaks in the WAXS spectrum of the resulting nanocomposite.
  • the relative viscosity (RV) of the resulting nanocomposite was equal to the neat control and its translucency indicated good clay dispersion.
  • a 4-9°C rise in recrystallization temperature vs. the control indicates that the nanoparticles are altering the crystal structure of the nylon matrix in the manner of nucleating agents.
  • Nylon 6 nanocomposite fiber spun from the polymerization autoclave and comprising 2.5% laponite RD silicate showed a measure of electrical conductivity under high voltage testing. At 5% and 10% concentrations, the melt viscosity was so high that the nanocomposite melt could not be discharged from the autoclave.
  • nanoclays produce enhanced modulus at the 0.5% and 1.0% levels, along with some increase in tenacity at 0.5%. They were also seen to be efficient nucleating agents for nylon 6.
  • Nylon 6,6 nanocomposites may be polymerized by standard industrial procedures as described in the "Nylon Plastics Handbook" (Melvin I. Kohan, Hanser Publishers, Kunststoff, 1995, pp. 17-23). Gelwhite L may be made into a concentrate of up to 20% in nylon 6 via in-situ polymerization (with Tamol 850, a sodium polymethacrylate from Rohm and Haas Company, to aid clay dispersion). These concentrates were extruded at the end of the third cycle of the standard polymerization process and given a water quench. The nanocomposites were pulverized and added back to a nylon 6,6 polymerization, either to the salt solution at the beginning of the process or later after the batch achieved a temperature of 220°C. The latter technique generated gels, and neither resulted in any enhancement to the mechanical properties of spun fiber.
  • a never-dried slurry of an ion exchanged Ca-montmorillonite in which the Ca 2+ ions have all been exchanged for Na + , and containing polyacrylate as peptizer was also polymerized into nylon 6,6 fiber at 1% concentration, but with no improvement in yarn properties. Melt viscosity was high, but spinnable. The resulting yarn appearance was smooth, but delustered.
  • the Ca + mined ores are attractive for fiber applications because of their whiter color. However, the aspect ratio of their exfoliated platelets is known to be lower than those from mined Na-montmorillonite.
  • An alternative embodiment for the preparation of silicate / polyamide nanocomposites via in- situ polymerization is to pre-disperse the clay at high concentration in a carrier (as a "concentrate") for addition to the polymerization vessel.
  • a carrier as a "concentrate”
  • Gelwhite L it was found possible to disperse Gelwhite L at concentrations of 10-30% in an aqueous solution comprising 25% (based on the weight of the clay component) of a solution of 70% epsilon caprolactam in water and l%-5% Tamol 850 dispersing agent. These dispersions remained stable for over three weeks at room temperature. Without the dispersing agent, the dispersion of Gelwhite L at concentrations of or above 10% become unpourable gels.
  • Laponite RD could be dispersed at a high concentration of 10% in a 70% solution of caprolactam in water by combining 3% Tamol® 850 with 100% ethylene glycol, both concentrations based on the weight of the clay.
  • Tetrasodium pyrophosphate (TSPP) and carboxymethyl cellulose (CMC) were found to not be effective peptizers to stabilize montmorillonite suspensions after addition to the nylon 6,6 salt solution, according to WAXS data.
  • Tamol® dispersing agent was effective in polymerizing 1.5-2% nanocomposites of Mineral Colloid BP in nylon blends comprising 20-30% nylon 6 in nylon 6,6 from aqueous mixtures of caprolactam and hexamethylene adipamide.
  • the viscosity of the 2% nanocomposite was so high that it could not be extruded from the reactor.
  • the copolymer composition is attractive because the lower salt concentration reduces clay flocculation while the caprolactam component enhances intercalation of the clay structure, leading to more efficient exfoliation.
  • Potassium tripolyphosphate has been found to be an effective peptizer for nanosilicates in nylon 6,6 salt solution. It is also believed to suppress gel formation. Spun and drawn fibers prepared by injecting stabilized Gelwhite slurry later in the nylon 6,6 polymerization cycle were bright and gel-free, unlike the nubs and fluorescent gels routinely obtained with TSPP and Tamol® 850 peptizers. Fiber containing 0.3% nanoclay retained its matrix properties.
  • a lauryl-dimethyl-3-sulfopropyl betaine (Ralufon DL from Raschip Corp.) with higher temperature stability successfully intercalated Gelwhite L pristine Ca-montmorillonite at 1% concentration in 70% caprolactam solution which, when injected late in the nylon 6,6 polymerization cycle, produced a nylon 6,6 fiber at 0.3% mineral concentration with good luster and absence of gel, along with acceptable mechanical properties.
  • Nylon 6,6 nanocomposites comprising 1% nanoclay were prepared from never-dried aqueous suspensions, with the exception of dry Gel- White H which had to be re-dispersed in water.
  • the pre-dispersions are further mixed under high shear with an Omni homogenizer for 10 minutes after introduction to the salt solution.
  • the Ca-montmorillonite slurry was ion exchanged with sodium ions and also contained an acrylic peptizer.
  • Samples 8515, 8517 and 8520 could not be extruded out of the polymerization autoclave due to their high melt viscosity, suggesting a significant degree of clay exfoliation despite the presence of a residual WAXS peak at 14.4A.
  • the greater breadth of the peak does indicate that the original lamina stacks in the clay have been reduced somewhat in thickness.
  • a nylon 6,6 nanocomposite comprising 1% nanoclay from Na-montmorillonite never-dried slurry showed high reinforcement efficiency with a 15% increase in tensile modulus.
  • Sample 8522 was injection molded into tensile test bars which showed a 15% increase in modulus from 435 to 500 kpsi, a highly efficient reinforcement from the small amount of clay present.
  • Gelwhite L were prepared in a small autoclave from a 10% clay pre-dispersion in 70% aqueous caprolactam solution containing 1% each of KTPP and Tamol 850 based on the weight of the clay.
  • the clay slurry was injected into a nylon 6,6 polymerization during the second cycle of the process at 235°C.
  • Modulus increased by 10-20% in the spun fibers at both concentration levels, although this advantage was retained after drawing only in the carpet fiber at the lower concentration level.
  • Tenacity and elongation of both spun and drawn fibers of both types showed small decreases. It was later shown to be preferable to omit the Tamol ingredient in this particular formulation.
  • Pristine sepiolite a chain-like silicate, has been demonstrated to be equally effective as montmorillonite or hectorite for nylon fiber reinforcement via in-situ polymerization. At 0.1% concentration it provides a high draw capability and enhanced mechanical properties. At 6.5 draw ratio the following fiber properties were obtained vs. a neat nylon control fiber: 84 vs. 76 g/d modulus, 10.2 vs. 9.1 g/d tenacity and 12.3 vs. 10.4% elongation to fail. The nylon matrix RV was equivalent to the neat nylon control.
  • Sepiolite (1%) increased flex modulus by 13% in nylon 6,6 polymerized in a lab autoclave.
  • the sepiolite nanocomposites did not demonstrate as great an improvement on the nanocomposite as in the smaller scale experiments.
  • Injection moldings containing 0.09% by weight pristine sepiolite showed lower reinforcement than the corresponding laponite materials.
  • Tensile strength still increased significantly from 11.1 to 12.0 kpsi in comparison to the unreinforced nylon 6,6 control. The increase in modulus was only a modest 6%, while elongation still reached 30% strain.
  • Silane particularly aminopropyltriethoxysilane
  • polyamides such as nylon 6,6
  • the salt solution may be added to the salt solution along with the nanoclay prior to polymerization.
  • it provided no significant benefit to the properties of the resulting nanocomposite fibers also comprising low (0.1%) levels of nanoclay.
  • the interfacial strengthening usually attributed to silanes in melt compounded systems can also be effective via in-situ polymerization.
  • the silane alone showed some reinforcing potential of its own in drawn fiber.
  • the higher aspect ratio reinforcements in general produce higher properties in fiber drawn from in-situ polymerized nylon 6,6 nanocomposites.
  • montmorillonite and hectorite are more effective than laponite B, which in turn is more effective than laponite RD.
  • Crystallinity is increased slightly and recrystallization temperatures generally increased (by up to 8°C) through the incorporation of nanoclay during polymerization.
  • Sepiolite, saponite and, to a lesser extent, hectorite are the most efficient nanosilicate nucleators.
  • fibers spun and drawn from in-situ polymerized nylon 6,6 nanocomposites at the pilot plant scale comprise montmorillonite, hectorite and laponite B, both pristine and ion exchanged with ammonium cations.
  • Increases of 15% in modulus and tenacity were achieved along with a 30% increase in creep resistance at a low mineral concentration of only 0.1% by weight that would be significant for tire cord applications.
  • Higher increases of up to 30% in modulus with 10% in tenacity were observed at the bench scale.
  • the 2% secant modulus of 0.1% pristine hectorite nanocomposite drawn carpet yam of 16.6 g/denier was 44% higher than the 11.7 g/denier control yarn produced in the same test and drawn to the same denier. Elongation to fail was equivalent to the control, while tenacity was enhanced slightly.
  • the good performance of this nanocomposite may be attributed to pre-dispersion of the silicate in a minor caprolactam component of the formulation.
  • Dihydroxyethyl octadecylammonium is the preferred cation exchanged onto the phyllosilicate minerals for in-situ polymerization in nylon 6,6.
  • a nanocomposite in-situ polymerized with either 0.2 and 0.4% of montmorillonite previously treated with this cation showed improved appearance retention in carpet walk testing. Due to their less hydrophilic nature, organoclays are pre-dispersed at up to 5% concentration directly in nylon salt solution rather than in pure water, as is preferred for the pristine minerals.
  • a slight inhibition of nylon 6,6 polymerization that may occur at higher silicate concentrations (e.g., 2%) may be overcome by increasing reactor residence time in the finishing cycle by about 30%.
  • the ideal mineral concentration for fiber spinning appears to be below about 1%, preferably from about 0.1% to about 0.2% by weight.
  • high injection molded properties were found for 1.5% silicate content: tensile strength of 91 MPa, modulus of 3.4 GPa and ultimate elongation of 47%, whereas a typical near nylon 6,6 homopolymer would display 80 MPa, 3.0 GPa, and 60%, respectively.
  • Fiber applications via the in-situ polymerization approach benefit from the lower modulus targets vs. plastic molding applications, such that lower clay concentration levels may be used where nanoscale interactions play a greater role.
  • Higher orientation levels can be generated in the fiber spinning and drawing processes than in injection molding.
  • the use of higher draw temperature further improves nanocomposite yarn performance by controlling molecular deformation.
  • Luster, smoothness (absence of nubbs) and opacity are indicators of the residual particle size of the clay inclusions in spun and drawn fibers.
  • Solid statepolymerization was performed for 1.5 hours at 200°C using nylon 6,6 which had been in-situ polymerized with four different silicates. Molecular weights were determined before and after solid state polymerization. The nanocomposite samples were found to increase in molecular weight similarly to neat nylon 6.6.

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Abstract

La polymérisation in situ de monomères de polyamide et de matériaux de silicate permet de produire des matériaux nanocomposites de polyamide présentant les propriétés physiques désirées. Les matériaux nanocomposites ainsi produits comprennent des homopolymères et des copolymères. Le choix des monomères, des types de silicate et les conditions de polymérisation permettent de modifier les propriétés de ces matériaux nanocomposites.
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AU2002222370A1 (en) * 2001-12-18 2003-06-30 Pirelli & C S.P.A. Optical fibre with mechanically reinforced coating
KR100457855B1 (ko) * 2001-12-31 2004-11-18 김형수 초음파를 이용하여 박리구조의 나노복합재료를 제조하는 방법
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EP1589079A4 (fr) * 2003-01-20 2008-07-30 Teijin Ltd Nanotube en carbone revetu de polymere de condensation aromatique
AU2005258162B2 (en) * 2004-06-21 2010-05-06 Dupont Teijin Films U.S. Limited Partnership Article comprising polyester multilayer film
DE102005042138A1 (de) 2005-09-05 2007-03-08 Deutsches Wollforschungsinstitut An Der Rwth Aachen E.V. Verfahren zur Herstellung von Verbundwerkstoffen
CN1990549B (zh) * 2005-12-30 2010-05-12 上海杰事杰新材料股份有限公司 蒙脱土/尼龙6纳米复合材料及其制备方法
US8198355B2 (en) 2006-06-15 2012-06-12 E. I. Du Pont De Nemours And Company Nanocomposite compositions of polyamides and sepiolite-type clays
US20090142585A1 (en) * 2007-11-08 2009-06-04 Toshikazu Kobayashi Nanocomposite compositions of polyamides, sepiolite-type clays and copper species and articles thereof
CN101434745B (zh) * 2007-11-16 2011-10-12 比亚迪股份有限公司 一种聚合物合金及其制备方法
CN101450993B (zh) * 2007-12-05 2010-09-15 中国石油化工股份有限公司 一种无卤阻燃尼龙6的制备方法
FR2934598B1 (fr) * 2008-07-30 2012-11-30 Rhodia Poliamida E Especialidades Ltda Procede de fabrication de matrice polymerique thermoplastique
ES2335847B9 (es) 2008-10-01 2016-12-30 Nanobiomatters, S.L. Materiales nanocompuestos con propiedades de barrera a la radiacion electromagnetica y procedimiento para su obtencion
EP2414457B1 (fr) 2009-04-03 2013-01-09 Basf Se Procédé pour produire des matériaux composites
JP5602837B2 (ja) 2009-05-08 2014-10-08 ビーエーエスエフ ソシエタス・ヨーロピア 粒子状ナノコンポジット材料を製造する方法
WO2011128352A2 (fr) * 2010-04-14 2011-10-20 Wingspeed Ag Procédé de préparation de polyamide 6 modifié
KR101582132B1 (ko) * 2010-12-28 2016-01-04 상하이 지니어스 어드밴스트 머티리얼 코퍼레이션, 리미티드. 나노 입자/폴리아미드 복합 재료, 그 제조방법 및 그 용도
WO2014009451A1 (fr) 2012-07-12 2014-01-16 Basf Se Procédé de production de matériaux composites
WO2014049103A1 (fr) 2012-09-28 2014-04-03 Basf Se Procédé de production de matériaux composites
CN103788624B (zh) * 2012-10-26 2017-12-05 上海杰事杰新材料(集团)股份有限公司 一种芳纶纤维增强耐高温尼龙复合材料及其制备方法
KR101488299B1 (ko) * 2013-02-05 2015-01-30 현대자동차주식회사 난연성 폴리아미드 수지 조성물
CN103570941B (zh) * 2013-11-21 2016-01-20 倪任林 一种纳米聚酰胺复合材料及其生产方法
CN104672374A (zh) * 2013-11-27 2015-06-03 中国石油大学(北京) 一种纳-微米结构中间体微粒的可控分散方法及由其制备的复合材料
CN105504802A (zh) * 2015-12-30 2016-04-20 浙江博尼锦纶科技有限公司 一种有机硅酸镁锂-尼龙6复合材料及其制备方法
CN106118037A (zh) * 2016-06-22 2016-11-16 陆志强 一种高强度耐腐蚀pa/abs/pbi塑料合金及其制备方法
CN108003609A (zh) * 2017-12-25 2018-05-08 桐城市祥泰塑业有限公司 一种溴化插层蒙脱土改性尼龙材料及其制备方法
CN111732726B (zh) * 2020-06-19 2022-04-08 山东东辰瑞森新材料科技有限公司 一种高流动本体阻燃长碳链尼龙及其制备方法
CN113929936A (zh) * 2021-11-24 2022-01-14 四川朗迪新材料有限公司 一种玻纤增强原位聚合阻燃尼龙一次成型加工方法

Family Cites Families (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4739007A (en) * 1985-09-30 1988-04-19 Kabushiki Kaisha Toyota Chou Kenkyusho Composite material and process for manufacturing same
JPH0778089B2 (ja) * 1987-03-26 1995-08-23 株式会社豊田中央研究所 複合材料の製造方法
JPH0747644B2 (ja) * 1989-05-19 1995-05-24 宇部興産株式会社 ポリアミド複合材料及びその製造方法

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
See references of WO0112678A1 *

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WO2001012678A1 (fr) 2001-02-22
CN1373775A (zh) 2002-10-09
JP2003507498A (ja) 2003-02-25
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BR9917441A (pt) 2002-05-14

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