Method for a composite material impregnated with thermoplastic polymer, obtained from a prepolymer and a chain extender

Patent metadata

Field	Value
Publication number	US-10240016-B2
Application number	US-201515304657-A
Country	US
Kind code	B2
Filing date	Apr 15, 2015
Priority date	Apr 15, 2014
Publication date	Mar 26, 2019
Grant date	Mar 26, 2019

Abstract

A process for a composite material, including an assembly of one or more reinforcing fibers, impregnated with at least one thermoplastic polymer with a glass transition temperature Tg of less than or equal to 75° C. and a melting point of from 150° C. to less than 250° C. or a Tg of greater than 75° C., the process including: i) a step of impregnating said assembly in bulk melt form with at least one thermoplastic polymer, which is the product of polymerization by polyaddition reaction of a reactive precursor composition including: a) at least one prepolymer P(X)n of said thermoplastic polymer, and b) at least one chain extender, represented by Y-A-Y, ii) a step of cooling and obtaining a fibrous preimpregnate, and iii) a step of processing and final forming of said composite material.

First claim

The invention claimed is:

1. A process for manufacturing a composite material comprising an assembly of one or more synthetic or natural reinforcing fibers, melt-impregnated with at least one thermoplastic polymer as matrix, having a glass transition temperature Tg of less than or equal to 75° C. and a melting point (Tm) ranging from 150° C. to less than 250° C. or a Tg of greater than 75° C., said process comprising:
i) a step of impregnating said assembly in bulk melt form with at least one thermoplastic polymer, having a viscosity at the impregnation temperature in bulk melt form not exceeding 200 Pa·s, with said at least one polymer being the product of polymerization by polyaddition reaction of a reactive precursor composition comprising:
a) at least one prepolymer P(X)n of said thermoplastic polymer, comprising a hydrocarbon-based molecular chain P and bearing at its ends n identical reactive functions X, with X being a reactive function from among: OH, NH 2 or COOH, with n ranging from 1 to 3, and a number-average molecular mass Mn ranging from 500 to 10,000 g·mol −1 ,
b) at least one chain extender, represented by Y-A-Y, comprising two identical functions Y that are reactive with at least one of said functions X of said prepolymer a), with A being a covalent single bond bonding the two functions Y or a non-polymeric hydrocarbon-based diradical,
ii) a step of cooling and obtaining a fibrous preimpregnate,
iii) a step of processing and final forming of said composite material.

2. The process as claimed in claim 1 , wherein the thermoplastic polymer is obtained by polymerization of a precursor reactive composition comprising a prepolymer of said impregnation polymer, chosen from: a polyamide, a polyester, copolymers thereof including polyamide-polyethers or mixtures thereof.

3. The process as claimed in claim 1 , wherein:
the prepolymer P(X)n corresponds to n=1 or 2,
X is a reactive function chosen from: OH, NH 2 , COOH,
said hydrocarbon-based molecular chain P has a semi-cycloaliphatic or semi-aromatic structure and
said polymer has a Tg of greater than 75° C.

4. The process as claimed in claim 1 , wherein the thermoplastic polymer is obtained from a precursor composition comprising an extender b) with said function Y being chosen from the following relative to the function X of said prepolymer:
for X being NH 2 or OH:
Y chosen from the following groups: maleimide, optionally blocked isocyanate, oxazinone and oxazolinone, cyclic anhydride, epoxide,

and
when X is COOH:
Y chosen from the following groups: oxazoline, oxazine, imidazoline or aziridine, such as 1,1′-iso- or terephthaloyl-bis(2-methylaziridine).

5. The process as claimed in claim 1 , wherein when Y is chosen from oxazinone, oxazolinone, oxazine, oxazoline and imidazoline, and A represents a covalent single bond between the two functions Y or an alkylene —(CH 2 )m- with m ranging from 1 to 14 and or A represents a cycloalkylene or an alkyl-substituted or unsubstituted arylene, from among o-, m- or p-phenylenes or naphthalenic arylenes.

6. The process as claimed in claim 1 , wherein the weight content of said extender in said thermoplastic polymer ranges from 1% to 20%.

7. The process as claimed in claim 1 , wherein a chain of said polymer comprises at least two chains of said prepolymer a) linked together via an extender molecule b), the number of prepolymer chains a) per chain of said polymer ranging from 2 to 80.

8. The process as claimed in claim 1 , wherein the polymer is semi-crystalline with a Tg of less than 75° C. and a melting point Tm ranging from 150° C. to less than 250° C.

9. The process as claimed in claim 1 , wherein the prepolymer a) bears a function X=carboxyl with n=2 (±0.1) and in that said extender bears a function Y=oxazoline.

10. The process as claimed in claim 9 , wherein the thermoplastic polymer has a repeating unit structure according to formula (I) below:

with R=A with A being as defined above and chosen from a covalent single bond or a diradical of an optionally substituted aliphatic or cycloaliphatic or aromatic hydrocarbon-based chain,
R′ being an optionally substituted aliphatic or cycloaliphatic or aromatic hydrocarbon-based chain in which the shortest chain linking the neighboring —O— and —NH— units comprises 2 or 3 carbon atoms,
P being the chain of said prepolymer a) bearing functions X=carboxyl.

11. The process as claimed in claim 9 , wherein the extender is chosen from: phenylene-bis-oxazolines.

12. The process as claimed in claim 1 , wherein the prepolymer a) is a polyamide prepolymer obtained from: the polycondensation of at least one linear or branched aliphatic diamine and of at least one aromatic and/or cycloaliphatic dicarboxylic acid comprising at least one optionally substituted ring of 4, 5 or 6 carbon atoms and/or the polycondensation of at least one cycloaliphatic diamine with at least one linear or branched aliphatic, cycloaliphatic or aromatic dicarboxylic acid and optionally with the presence of at least one compound chosen from: a lactam, an aminocarboxylic acid or the stoichiometric combination of an aliphatic dicarboxylic acid and an aliphatic diamine.

13. The process as claimed in claim 1 , wherein the thermoplastic polymer is a semi-aromatic and/or semi-cycloaliphatic homopolyamide or copolyamide polyamide, corresponding to one of the following formulae: polyamides from among: 8.T, 9.T, 10.T, 11.T, 12.T, 6.T/9.T, 9.T/10.T, 9.T/11.T, 9.T/12.T, 9/6.T, 10/6.T, 11/6.T, 12/6.T, 10/9.T, 10/10.T, 10/11.T, 10/12.T, 11/9.T, 11/10.T, 11/11.T, 11/12.T, 12/9.T, 12/10.T, 12/11.T, 12/12.T, 6.10/6.T, 6.12/6.T, 9.10/6.T, 9.12/6.T, 10.10/6.T, 10.12/6.T, 6.10/9.T, 6.12/9.T, 9.10/9.T, 9.12/9.T, 10.10/9.T, 10.12/9.T, 6.10/10.T, 6.12/10.T, 9.10/10.T, 9.12/10.T, 10.10/10.T, 10.12/10.T, 6.10/12.T, 6.12/12.T, 9.10/12.T, 9.12/12.T, 10.10/12.T, 11/6.T/9.T, 11/6.T/10.T, 11/6.T/11.T, 11/6.T/12.T, 11/9.T/10.T, 11/9.T/11.T, 11/9.T/12.T, 11/10.T/11.T, 11/10.T/12.T, 11/11.T/12.T, 6.T/10.T, 6.T/11.T, 6.T/12.T, 10.T/11.T, 10.T/12.T, 11.T/12.T, 12/6.T/10.T, 12/6.T/11.T, 12/6.T/12.T, 12/9.T/10.T, 12/9.T/11.T, 12/9.T/12.T, 12/10.T/11.T, 12/10.T/12.T, 12/11.T/12.T or preceding terpolymer polyamides with 12/replaced with 9/, 10/, 6.10/, 6.12/, 10.10/, 10.12/, 9.10/and 9.12/or all the polyamides mentioned above in which terephthalic (T) is partially or totally replaced with isophthalic (I), naphthalene-2,6-dicarboxylic and/or with 1,3- or 1,4-CHDA (cyclohexanedicarboxylic acid), with all or some of the aliphatic diamines possibly being replaced with cycloaliphatic diamines or all the polyamides mentioned above, with replacement of the C 6 to C 12 aliphatic diamine with a cycloaliphatic diamine from among BMACM, BACM and/or IPDA and with replacement of all or some of the aromatic diacid T with a linear or branched C 6 to C 18 aliphatic diacid.

14. The process as claimed in claim 1 , wherein the thermoplastic polymer is a semi-crystalline polyamide.

15. The process as claimed in claim 1 , comprising a step i′) prior to the impregnation step i), of preparation of said polymer by polyaddition reaction of said precursor reactive composition comprising said prepolymer a) and said extender b), said reaction being performed in bulk in melt form in an extruder transferring on-line said molten polymer onto said assembly of fibers for said impregnation step i).

16. The process as claimed in claim 1 , wherein the impregnation step i) is performed in a mold for the final processing of sa

Assignees

• Arkema France

Inventors

• Hochstetter Gilles
• Briffaud Thierry
• Capelot Mathieu

Classifications

• C08J2377/10

  Polyamides derived from aromatically bound amino and carboxyl groups of amino carboxylic acids or of polyamines and polycarboxylic acids · CPC title

• C08L77/06

  Polyamides derived from polyamines and polycarboxylic acids (C08L77/10 takes precedence) · CPC title

• B29C45/0005

  using fibre reinforcements · CPC title

• C08J5/24 Primary

  Impregnating materials with prepolymers which can be polymerised in situ, e.g. manufacture of prepregs · CPC title

• C08K5/353

  Five-membered rings · CPC title