WO2019121826A1

WO2019121826A1 - Thermoplastic composites and corresponding fabrication methods and articles

Info

Publication number: WO2019121826A1
Application number: PCT/EP2018/085708
Authority: WO
Inventors: Anthony BOCAHUT; Thierry Badel; Pierre-Yves Lahary
Original assignee: Rhodia Operations
Priority date: 2017-12-18
Filing date: 2018-12-18
Publication date: 2019-06-27
Also published as: WO2019121824A1; WO2019121823A1

Abstract

Thermoplastic composites and corresponding fabrication methods and articles The present invention relates to thermoplastic composites comprising a non-crosslinked polyamide, and non-continuous and/or continuous fibers, such as glass or carbon fibers. The invention further relates to the fabrication of thermoplastic composites. The invention still further relates articles incorporating the thermoplastic composites.

Description

Thermoplastic composites and corresponding fabrication methods and articles

FIELD OF THE INVENTION

The invention relates to thermoplastic composites comprising a non-crosslinked polyamide, and non-continuous and/or continuous fibers, such as glass or carbon fibers. The invention further relates to the fabrication of thermoplastic composites. The invention still further relates articles incorporating the thermoplastic composites.

BACKGROUND OF THE INVENTION

Thermoplastic composites are gaining a significant amount of attention as a potential replacement for metal parts. Relative to metal parts, thermoplastic composites can provide a significant reduction in weight and cost, while simultaneously providing desirable or superior mechanical performance. One type of polymer used in thermoplastic composites is amorphous polypthalamide (“PPA”) polymers. The popularity of amorphous PPA polymers in thermoplastic composites is at least in part due to the fact that they form crack-free composites. However, due to their high viscosity, time processing of thermoplastic composites is important, which can lead to significant processing costs.

BRIEF DESCRIPTION OF THE DRAWINGS

Fig. 1 is a schematic depiction showing a perspective view of an embodiment unidirectional composite.

Fig. 2 is a schematic depiction showing a perspective view of an embodiment of a multidirectional composite in which the reinforcing fibers are oriented as a woven fabric.

Fig. 3 is a schematic depiction showing a perspective view of an embodiment of a multidirectional composite in which the continuous reinforcing fibers are oriented as a layered fabric. DETAILED DESCRIPTION OF THE INVENTION

Described herein are thermoplastic composites comprising a non-crosslinked polyamide, and at least one non-continuous and/or continuous fibers. It was surprisingly discovered that use of non-crosslinked polyamides, having a high melt fluidity and good mechanical properties, provided for crack-free thermoplastic composites. In general, fabrication of thermoplastic composites, notably from semi-crystalline PPA polymers, can result in composites having significant visible cracking, which compromises the mechanical integrity of the composite and makes in undesirable for use in many application settings. Applicant discovered that crack-free thermoplastic composites can be formed from non- crosslinked polyamides having a high melt fluidity. The composites can be formed using melt impregnation techniques, well known in the art. The composites can be desirably used in a wide range of application settings including, but not limited to automotive, aerospace, oil and gas and mobile electronic device applications.

It was surprisingly found that non-crosslinked polyamides having a selected low melt viscosity while having high mechanical performances provided for crack free thermoplastic composite.

The composite thermoplastic according to the invention comprises a non-crosslinked polyamide comprising structural units of formula (1):

Here, and throughout the invention any bond crossing a ring structure means that the following atom is connected to any position of the ring by replacing a hydrogen atom. For example, in formula (1), the next (not shown) atom to which the pyridine ring is linked may be attached at 2-, 3- or 4-position relative to the nitrogen atom. The next (not shown) atom to which the phenyl ring is linked may be attached at ortho, meta or para position relative to the carboxy group.

In one embodiment, the polyamide according to the invention comprises structural units of formula (2):

wherein R¹ is hydrogen, an organic monovalent residue, or an organic divalent residue which forms a ring together with R , and

R 2 and R 3 are independently a bond or an organic divalent residue.

In the above structural unit of formula (2), R¹ preferably is hydrogen or a linear, branched, cyclic and/or aromatic Ci_₃o hydrocarbon residue. Optionally, this residue may form a ring together with R . If such ring is formed, any atom of the R hydrocarbon residue may be attached to any atom of R .

In the context of the present invention the term "hydrocarbon residue" is understood as a residue which mainly consists of carbon and hydrogen atoms. It is, however, also possible that the hydrocarbon residue contains heteroatoms, such as O, N, P, S, etc. In a preferred embodiment, the hydrocarbon residue consists of carbon and hydrogen atoms.

R and R may independently be a bond or a linear, branched, cyclic and/or aromatic Ci-3o hydrocarbon residue, wherein the hydrocarbon residue is defined as above.

In a preferred embodiment, R¹ in the structural unit of formula (2) is hydrogen or a linear, branched, cyclic and/or aromatic C1-30 hydrocarbon residue which optionally forms a ring together with R , and R and R are independently a bond or a linear, branched, cyclic and/or aromatic Ci_3o hydrocarbon residue.

In a further embodiment, R¹ is hydrogen or a Ci_₆ alkyl residue, which optionally forms a ring together with R , R is a bond or a linear, branched and/or cyclic Ci-₂₄ alkyl residue, preferably a bond or a linear C1-24 alkyl residue, more preferably a bond or a Ci_6 alkyl residue, and R is a bond, a Ci_₆ alkylaryl residue or an aryl residue preferably a bond or a phenyl residue.

The polyamide according to the invention may comprise other structural units in addition to the above structural units. For example, the polyamide may comprise additional structural units being derived from caprolactame, hexamethylenediamine, phenylenediamine, adipic acid, etc. It is, however, preferred that such additional structural units are present in an amount of less than 50 %, preferably less than 30 % and even more preferably of less than 20 % of the total number of structural units in the polyamide. More preferably, the polyamide is a homopolymer which consists of structural units of formula (2).

The polyamide is obtainable by polymerization of a diamine of formula (3):

wherein R 1 and R 2 are defined as above;

with an aromatic dicarboxylic acid, ester or halogenide of formula (4):

wherein R is defined as above and X is hydroxy, halogen, Ci_₆ alkoxy or C2-20 aryloxy, preferably phenoxy.

Without otherwise specified, in the instant specification polyamide means homopolyamide or copolyamide.

The polyamide may be amorphous or semi-crystalline. By semi-crystalline is meant a polyamide having an amorphous phase and a crystalline phase, in particular the degree of crystallinity is in the range of 1 to 85%. What is meant by amorphous is a polyamide having no crystalline phase detected by thermal analysis, such as DSC (Differential Scanning Calorimetry) and with X-ray diffraction. Heat of fusion (DHG) may range from 2 to 170 J/g as measured according to ASTM D3418 using a heating and cooling rate of lO°C/min.

By thermoplastic polyamide is meant a polyamide having a temperature above which the material is softening and melts without being degraded and which is hardening below such a temperature. The polyamide may comprise an amount of repeating units of formula (1), comprising at least one amide bond, from 2 to 100%, preferably from 10 to 100% relative to the total number of repeating units in the polyamide.

In the instant specification homopolyamide means a polyamide comprising an amount of one repeating unit of at least 95% relative to the total number of repeating units in the polyamide. On the other hand copolyamide means a polyamide comprising less than 95% of one repeating unit relative to the total number of repeating units in the polyamide.

Advantageously, the polyamide is thermoplastic. The polyamide may be amorphous; in this case it may have a Tg£280°C, which can be measured according to ASTM D3418 using a heating and cooling rate of lOoC/min. The polyamide may also semi-crystalline, and may have a Tm of less or equal to 370°C, notably less or equal to 350°C, particularly comprised from l50°C to 370°C.

In one embodiment, the diamine from which the polyamide according to the invention is obtainable has the formula (5):

wherein R 2 is defined as above. Preferably, R 2 is attached at 2- or 4-position of the piperidine ring.

In another embodiment, the diamine, from which the polyamide according to the invention is obtainable has the formula (6):

wherein R⁴ is a bond or a linear, branched and/or cyclic Ci_₂₄ alkyl residue, preferably a bond or a linear Ci_₂₄ alkyl residue. In a preferred embodiment, the diamine from which the polyamide according to the invention is obtainable has the formula (7):

wherein n is an integer of 0 to 24, preferably 0 to 16, more preferably 2 to 16, even more preferably 3 to 10.

Examples of suitable diamines, from which the polyamide according to the invention can be obtained are 4,4'-bipiperidine, 4,4'-ethylenedipiperidine, 4,4'-trimethylenedipiperidine, 4- aminopiperidine, 4-(aminomethyl)piperidine, 2-(aminomethyl)piperidine, 3- (aminoethyl)piperidine, and 4-(aminobutyl)piperidine. Preferred diamines are 4,4'- trimethylenedipiperidine and 4-aminopiperidine.

The amount of diamine of formula (3) may be comprised from 2 to 100 mol %, preferably from 10 to 100 mol % relative to the total amount of diamine monomers in the polyamide.

The amount of repetitive units of formula (1) may be comprised from 2 to 100 mol %, preferably from 10 to 100 mol % relative to the total amount of repetitive units in the polyamide.

The polyamide may also comprise at least one other diamine. This diamine may respond to the following formula H₂N-R-NH₂ wherein R is an aliphatic, an aromatic, an arylaliphatic or an alkylaromatic radical. In particular the diamine R radical, especially when free of heteroatom such as oxygen, comprises from 1 to 36 carbon atoms and more particularly from 4 to 14 carbon atoms.

By“arylaliphatic” is meant a radical comprising an aromatic cycle and which is linked to the main chain of the polymer by bonds on the aliphatic part, such as the radical meta-xylylene, for example deriving from meta-xylylene diamine.

By“alkylaromatic” is meant a radical substituted by alkyl radical(s) and which is linked to the main chain of the polymer by bonds on the aromatic part. The radical R of the diamine may be free of heteroatom, or may comprise a heteroaom, such as oxygen, nitrogen, phosphorus or sulphur, in particular oxygen or sulphur, and more particularly oxygen. When a heteroatom is present it may:

-interrupt the chain of the radical, for example as an ether function,

-be in a functional group interrupting the chain of the radical, such as carbonyl or sulfone function, and/or

-be in a function grafted on the chain, such as a hydroxyl, sulfonic or sulfonate functions. When the R radical is aliphatic it may be free of heteroatom. The aliphatic radical may be alicyclic or cycloaliphatic.

The diamines comprising an alicyclic aliphatic radical may comprise from 2 to 12 carbon atoms, they may be chosen from l,2-diaminoethane, l,3-diaminopropane, l,3-diaminobutane, l,4-diaminobutane, l,5-diaminopentane, l,6-diaminohexane or hexamethylene diamine (HMD), 2-methyl pentamethylene diamine, 2-methyl hexamethylene diamine, 3-methyl hexamethylene diamine, 2,5-dimethyl hexamethylene diamine, 2,2-dimethylpentamethylene diamine, l,8-diaminooctane, methyl- 1, 8-diamino octane, in particular as the mixture of methyl- 1, 8-diamino octane and 1, 9-diamino nonane sold by Kuraray, 1, 9-diamino nonane, 5- methylnonane diamine, 1,10-diamino decane or decamethylenediamine, 1,12-diamino dodecane, or dodecamethylene diamine, 2,2,4-trimethyl hexamethylene diamine and/or 2,4,4- trimethyl hexamethylene diamine, and/or 2,2,7,7-tetramethyl octamethylene diamine.

The aliphatic radical R may be a cycloaliphatic radical, in particular mono- or di-cyclic. Each cycle may comprise from 4 to 8 carbon atoms, more particularly the cycle comprise 4, 5 or 6 carbon atoms. The cycloaliphatic radical may be saturated or unsaturated, and may comprise one or two double bonds. The cycloaliphatic radical may comprise from 6 to 12 carbon atoms. Among the cycloaliphatic diamines may be cited l,2-diaminocyclohexane, 1,3- diaminocyclohexane, l,4-diaminocyclohexane, in particular trans stereoisomer, the 4,4'- methylenebis(cyclohexyl amine), l,3-bis(aminomethyl)cyclohexane, 1,4- bis(aminomethyl)cyclohexane, diaminodicyclohexyl-methane, isophoronediamine, C36 diamine dimer, and 2,5-bis(aminomethyl)tetrahydrofuran, being cis, trans or a mixture of the stereoisomers.

The aliphatic radical R may also comprise at least one heteroatom, in particular oxygen. Among this type of radical may be cited polyether diamines such as Jeffamine® and Elastamine®, from Huntsman, in particular having a molecular weight ranging from 100 to 5000 g/mol.

The diamine R radical may be aromatic, arylaliphatic or alkylaromatic, it may comprise from 6 to 24 carbon atoms, in particular from 6 to 18 carbon atoms and more particularly from 6 to 10 carbon atoms. It may be a mono- or di-cyclo compound, such as benzene or naphthalene. The aromatic, arylaliphatic or alkylaromatic diamine may be chosen from diaminodiphenylmethane and its isomers, sulfonyldianiline and its isomers, 3,4'-oxydianiline also called 3,4'-diaminodiphenyl ether, l,3-bis-(4-aminophenoxy)benzene, l,3-bis-(3- aminophenoxy)benzene ; 4,4'-oxydianiline also called 4,4 '-diami nodi phenyl ether, 1,4- diaminobenzene, l,3-diaminobenzene, l,2-diaminobenzene, 2,2'- bis(trifluoromethyl)benzidene, 4,4'-diaminobiphenyl; 4,4'-diaminodiphenyl sulphide, 9,9'- bis(4-amino)fluorene; 4,4'-diaminodiphenyl propane, 4,4'-diaminodiphenyl methane, benzidine, 3,3'-dichlorobenzidine, 3,3'-diaminodiphenyl sulfone, 4,4'-diaminodiphenyl sulfone, 1, 5-diamino naphthalene, 4,4'-diaminodiphenyl diethylsilane, 4,4 '-diamino diphenysilane, 4,4'-diaminodiphenyl ethyl phosphine oxide, 4,4'-diamino diphenyl N-methyl amine, 4,4'-diamino diphenyl N-phenyl amine, m-phenylene diamine, p-phenylene diamine, m-xylylenediamine, p-xylylendiamine, and 2,5-bis(aminomethyl)furan.

In particular the diamine is chosen from m-phenylene diamine, p-phenylene diamine, m- xylylenediamine, p-xylylenediamine, hexamethylenediamine, 2-methylpentamethylene- diamine, l,lO-diaminodecane, l,l2-diaminododecane, diaminodiphenylmethane and sulfonyldianiline.

The aromatic dicarboxylic acid, ester or halogenide from which the polyamide according to the invention can be obtained is not particularly limited and can be selected from known aromatic dicarboxylic acids and their derivatives. In a preferred embodiment, the dicarboxylic acid, ester or halogenide has the above formula (4) wherein in a more preferred embodiment R is a bond or aryl, even more preferably a bond or phenyl.

The dicarboxylic acid may be an aromatic diacid [acid (AR)], in particular chosen from isophthalic acid, terephthalic acid, orthophthalic acid, naphthalene dicarboxylic acid, more particularly 2,6-napthalene dicarboxylic acid, 2,7-napthalene dicarboxylic acid, 1,4- napthalene dicarboxylic acid, 2,3-napthalene dicarboxylic acid, l,8-napthalene dicarboxylic acid, and l,2-napthalene dicarboxylic acid, 2,5-pyridine dicarboxylic acid, 2,4-pyridine dicarboxylic acid, 3,5-pyridine dicarboxylic acid, 2,2-bis-(4-carboxyphenyl)propane, bis(4- carboxyphenyl)methane, 2,2-bis-(4-carboxyphenyl)hexafluoropropane, 2,2-bis-(4- carboxyphenyl)ketone, 4,4'-bis(4-carboxyphenyl)sulfone, 2,2-bis(3-carboxyphenyl)propane, bis(3-carboxyphenyl)methane, 2,2-bis-(3-carboxyphenyl)hexafluoropropane, 2,2-bis-(3- carboxyphenyl)ketone, bis(3-carboxyphenyl)methane and 4, 4 '-biphenyl dicarboxylic acid, 2- hydroxyterephthalic acid, 5-hydroxyisophthalic acid, 4-hydroxyisophthalic acid, 2,5- dihydroxyterephthalic acid, sodium 5-sulfoisophthalate, or AISNa, lithium 5- sulfoisophthalate, or AISLi, potassium 5-sulfoisophthalate, or AISK, and 2,5- furandicarboxylic acid.

Examples of suitable dicarboxylic acids from which the poylamide according to the invention can be obtained are isophthalic acid, terephthalic acid, diphenic acid, and biphenyl-4, 4’- dicarboxylic acid, among which isophthalic acid, terephthalic acid and diphenic acid are preferred.

The polyamide mays also comprise also at least one, in particular one or two, and more particularly one dicarboxylic acid.

The dicarboxylic acid may be an aliphatic diacid [acid (AL), herein after], in particular alicyclic, and more particularly chosen from oxalic acid (HOOC— COOH), malonic acid (HOOC— CH_2— COOH) , succinic acid (HOOC— (CH₂)_2— COOH), glutaric acid (HOOC— (CH₂)_3— COOH), 2-methyl-glutaric acid (HOOC— CH(CH₃)—(CH₂)_2— COOH), 2,2- dimethyl- glutaric acid (HOOC— C(CH )_2— (CH₂)_2— COOH), adipic acid (HOOC— (CH₂)_4— COOH), 2,4,4-trimethyl-adipicacid (HOOC— CH(CH₃)—CH_2—C(CH₃)_2—CH_2— COOH), pimelic acid (HOOC— (CH₂)s— COOH), suberic acid (HOOC— (CH₂)_6— COOH), azelaic acid (HOOC— (CH₂)_7— COOH), sebacic acid (HOOC— (CH₂)_8— COOH), undecanedioic acid (HOOC— (CH₂)_9— COOH), dodecanedioic acid (HOOC— (CH₂)_I0— COOH), tridecanedioic acid (HOOC— (CH₂)n— COOH), tetradecanedioic acid (HOOC— (CH₂)_I2— COOH), pentadecanedioic acid (HOOC— (CH₂)_I3— COOH), hexadecanedioic acid (HOOC— (CH₂)i4— COOH), octadecanedioic acid (HOOC— (CH₂)_I6— COOH) and C₃₆ fatty acid dimer, in particular the one known as Pripol® by Croda.

The dicarboxylic acid may be a cycloaliphatic dicarboxylic acid comprising at least one carbocyclic ring having from 4 to 8 carbon atoms in the ring, like e.g. cyclohexane dicarboxylic acids, in particular such as 1, 2-cyclohexane carboxylic acid, 1, 3-cyclohexane dicarboxylic acid and 1, 4-cyclohexane dicarboxylic acid, 2,5-tetrahydrofurandicarboxylic acid, these acids may be cis, trans or mixtures thereof.

The dicarboxylic acid may be an aromatic diacid [acid (AR)] as previously described.

The polyamide may also comprise amino-acid repeating units. These repeating units may arise from lactams or amino-acids, in particular chosen from caprolactam, 6-aminohexanoic acid, lO-aminodecanoic acid, l l-aminoundecanoic acid, and l2-dodecanolactam.

The amount of repeating units arising from lactams or amino-acids may range from 0.1 to 50 mol %, in particular from 0.1 to 10 mol %, and more particularly from 0.1 to 5 mol % relative to the total amount of repeating units in the polyamide.

According to a preferred embodiment, the polyamide comprises recurring units derived from: TMDP.T (trimethylenedipepiridine, terephtalic acid)

TMDP.I (trimethylenedipepiridine, isophthalic acid)

TMDP.DA (trimethylenedipepiridine, diphenic acid)

TMDP.T/ 6T (trimethylenedipepiridine, terephtalic acid, hexamethylene diamine)

TMDP.I/ 61 (trimethylenedipepiridine, isophthalic acid, hexamethylene diamine)

TMDP.T / 9T (trimethylenedipepiridine, terephtalic acid, nonanediamine)

TMDP.I / 91 (trimethylenedipepiridine, isophthalic acid, nonanediamine)

TMDP.T / 10T (trimethylenedipepiridine, terephtalic acid, decanediamine)

TMDP.I / 101 (trimethylenedipepiridine, isophthalic acid, decanediamine)

TMDP.T/TMDP.6 (trimethylenedipepiridine, terephtalic acid, adipic acid)

TMDP.I/TMDP.6 (trimethylenedipepiridine, , isophthalic acid, adipic acid)

TMDP.T/TMDP.10 (trimethylenedipepiridine, terephtalic acid, sebacic acid)

TMDP.I/TMDP. 10 (trimethylenedipepiridine, isophthalic acid, sebacic acid)

According to another embodiment, the polyamide is a homopolyamide, in particular an aliphatic homopolyamide, obtained through polymerisation of one a diamine of formula (3), with a dicarboxylic acid of formula (4).

In addition, the polyamide may also comprise at least one, in particular one, mono-functional compound, such compounds may be chosen from monoamines, monoanhydrides, monoacids or a,b diacids such as they are able to from an intramolecular anhydride function, among chain limiters may be cited phthalic anhydride, l-aminopentane, l-aminohexane, 1- aminoheptane, l-aminooctane, l-aminononane, l-aminodecane, l-aminoundecane, 1- aminododecane, benzylamine, ortho-phthalic acid, or l,2-benzenedicarboxylic acid, acetic acid, propionic acid, benzoic acid, stearic acid or their mixtures.

Amino End Groups (AEG) of the polyamide may be comprised from 5 to 550 meq/kg. Carboxylic End groups (CEG) of the polyamide may be comprised from 5 to 550 meq/kg. AEG and CEG may be measured by an acido-basic titration after solubilisation of the polyamide in a solvent. Sum of end groups (AEG + CEG) values may be comprised from 10 to 900 meq/kg, preferably from 150 to 600 meq/kg.

The molecular weight of the polyamide according to the invention is not particularly limited and can be selected by the skilled person according to the requirements. It is, however, preferred that the number average molecular weight (Mn) of the polyamide is higher than 2,500 g/mol, preferably higher than 3,000 g/mol. On the other hand, in view of its moldability and mechanical properties the molecular weight of the polyamide should not exceed a certain limit. Therefore, the number average molecular weight (Mn) should be lower than 10,000 g/mol, preferably lower than 8,000 g/mol and even more preferably lower than 7,000 g/mol. The number average molecular weight (Mn) may range from 2,500 to 12,000 g/mol, notably from 2,500 to 10,000 g/mol, particularly from 3,000 to 10,000 g/mol. The number average molecular weight (Mn) of the polyamide may be calculated by end groups analysis.

The polyamide may also have a number average molecular weight (Mn) comprised from 6000 to 30000 g/mol, in particular from 10000 to 20000 g/mol, as notably determined by Size Exclusion Chromatography. The polyamide may have a weight- average molecular weight (Mw) comprised from 20000 to 150000 g/mol, in particular from 30000 to 100000 g/mol, as notably determined by Size Exclusion Chromatography. Preferably the Polydispersity Index, as a measure of the broadness of a molecular weight, defined by Mw/Mn ratio is comprised from 2 to 10, preferably from 2 to 8.

By determined by Size Exclusion Chromatography is meant a determination as follows: The Size Exclusion Chromatography for measuring relative molecular weights is performed in Hexafluoroisopropanol (HFIP) with 25 mM sodium trifluoroacetate (0.225 % w/w sodium trifluoroacetate in HFIP) as a solvent at 40°C, followed by refractometry RI. Determination of the relative molecular weight and molecular weight distribution is realised by a conventional calibration with polymethylmethacrylate standards (PMMA). The number average molecular weight of the polyamide may notably be controlled by the following means:

-by using chain limiter(s), i.e. mono -functional compounds, in particular such as defined above,

-by a stoechiometric desequilibrium r=[poly carboxylic acid]/[diamine], wherein r may range from 0.8 to 1.2, preferentially from 0.9 to 1.1,,

-by adjusting the synthesis parameters, such as the reaction time, temperature, humidity, or pressure, or

-by a combination of this different means.

One advantage of the polyamides according to the invention is their low glass transition temperature. Preferably, the glass transition temperature of the polyamide is below 2l0°C, more preferably below l80°C and even more preferably below l50°C.

The polyamide of the invention may be obtained by molten polymerisation from mixtures of monomers or from their salts.

The polyamide may be obtained from polymerization medium which can, for example, be an aqueous solution comprising the monomers or a liquid comprising the monomers. Advantageously, the polymerization medium comprises water as solvent. This facilitates the stirring of the medium and thus its homogeneity. The polymerization medium can also comprise additives, such as chain-limiting agents. The polyamide is generally obtained by polycondensation between the various monomers, present in all or in part, in order to form polyamide chains, with formation of the elimination product, in particular water, a portion of which may be vaporized. The polyamide is generally obtained by heating, at high temperature and high pressure, for example an aqueous solution comprising the monomers or a liquid comprising the monomers, in order to evaporate the elimination product, in particular the water, present initially in the polymerization medium and/or formed during the polycondensation, while preventing any formation of solid phase in order to prevent the mixture from setting solid.

The polycondensation reaction may be carried out at a pressure from 20 mbar to 15 bar, notably from 100 mbar to 1 bar, for instance 200 to 500 mbar.

The polycondensation reaction may be carried out at a temperature from 100 to 380°C, in particular from 180 to 300°C, even more particularly from 250 to 300°C. The polycondensation may be continued in the molten phase at atmospheric or reduced pressure, so as to achieve the desired degree of progression.

The polycondensation product is a molten polymer or prepolymer. It can comprise a vapour phase essentially composed of vapour of the elimination product, in particular of water, capable of having been formed and/or vaporized.

This product can be subjected to stages of separation of vapour phase and of finishing in order achieving the desired degree of polycondensation. The separation of the vapour phase can, for example, be carried out in a device of cyclone type. Such devices are known.

The finishing consists in keeping the polycondensation product in the molten state, under a pressure in the vicinity of atmospheric pressure or under reduced pressure, for a time sufficient to achieve the desired degree of progression. Such an operation is known to a person skilled in the art.

The crystallinity of the non-crosslinked polyamides can be determined by measuring the heat of the fusion of the non-crosslinked polyamide (“AH_f”). In some embodiments, the non-crosslinked polyamides of interest herein can in particular exhibit a heat of fusion of no more than 75 Joules per gram (“J/g”). In some embodiments, the non-crosslinked polyamides can have a heat of fusion of no more than 50 J/g or no more than 40 J/g. The heat of fusion can be measured as described below.

In some embodiments, the non-crosslinked polyamides can in particular exhibit a selected thermal window, defined by the difference in the degradation temperature (“Td”) and the melting temperature (“Tm’j of the non-crosslinked polyamide, as represented by the following formula: T_{d -} T_m of at least 60° C. In some embodiments, the non-crosslinked polyamides can have a thermal windows of no more than 200° C or no more than 120° C. Td and Tm can be measured as described below and in the examples.

The non-crosslinked polyamide melting temperature (“T_m”) and heat of fusion (“AH_f”) can be measured according to ASTM D3418 standard method using a differential scanning calorimeter (TA Instruments DSC Q20) and a liquid nitrogen cooling system operated with TA Thermal Advantage and Universal Analysis software. The measurements can be carried out using a heating and cooling rates of 10° C/min. in a nitrogen atmosphere. The T_m and AH_f values can be determined from the second heating scan. In some embodiments, the non-crosslinked polyamide may be contained in a polymer matrix. Generally, the concentration of the non-crosslinked polyamide in the polymer matrix is at least 50 wt.%, at least 60 wt.%, at least 70 wt.% at least 80 wt.%, at least 90 wt.%, at least 95 wt.% or at least 99.5 wt.%, or equal to 100 wt.%, relative to the total weight of the matrix composition. Of course the non-crosslinked polyamide of the polymer matrix can include a plurality of distinct non-crosslinked polyamide. In such embodiments, the total concentration of the non-crosslinked polyamide is within the ranges described above.

In some embodiments, in addition to the non-crosslinked polyamide, the polymer matrix can further include optional additives, including but not limited to, antioxidants (e.g. ultraviolet light stabilizers and heat stabilizers), processing aids, nucleating agents, lubricants, flame retardants, a smoke-suppressing agents, anti-static agents, anti-blocking agents, and conductivity additives such as carbon black.

In some embodiments, the thermoplastic composite includes at least 10 wt.%, at least 20 wt.%, at least 25 wt.%, at least 30 wt.%, at least 35 wt.% or at least 40 wt.% of the polymer matrix, relative to the total weight of the composite. When the concentration of the non-crosslinked polyamide in the polymer matrix is equal to 100% relative to the total weight of the matrix composition, the thermoplastic composite includes at least 10 wt.%, at least 20 wt.%, at least 25 wt.%, at least 30 wt.%, at least 35 wt.% or at least 40 wt.% of the non- crosslinked polyamide, relative to the total weight of the composite.

Additionally or alternatively, the thermoplastic composite includes no more than 90 wt.%, no more than 80 wt.%, no more than 70 wt.%, no more than 60 wt.%, no more than 55 wt.%, no more than 50 wt.%, no more than 45 wt.%, or no more than 25 wt.% of the polymer matrix, relative to the total weight of the composite. When the concentration of the non-crosslinked polyamide in the polymer matrix is equal to 100% relative to the total weight of the matrix composition, the thermoplastic composite includes no more than 90 wt.%, no more than 80 wt.%, no more than 70 wt.%, no more than 60 wt.%, no more than 55 wt.%, no more than 50 wt.%, no more than 45 wt.%, or no more than 25 wt.% of the non-crosslinked polyamide, relative to the total weight of the composite.

The Reinforcing Fibers

The thermoplastic composite includes non-continuous and/or continuous fibers, which are non-continuous and/or continuous reinforcing fibers. The reinforcing fiber is selected from glass fiber, carbon fibers, aluminum fiber, titanium fiber, magnesium fiber, boron carbide fibers, rock wool fiber, steel fiber, aramid fiber, polyester fibers natural fiber (e.g. cotton, linen, hemp and wood) and any combination of one or more, thereof. Preferably, the reinforcing fiber is glass fiber or carbon fiber. Preferably, the reinforcing fiber is a continuous reinforcing fiber, meaning the reinforcing fibers have an average length in the longest dimension of at least 5 millimeters (“mm”), at least 10 mm, at least 25 mm or at least 50 mm. In one embodiment, the thermoplastic composite includes glass or carbon fibers.

The thermoplastic composite includes at least 10 wt.%, at least 20 wt.%, at least 25 wt.%, at least 30 wt.%, at least 35 wt.%, at least 40 wt.%, at least 45 wt.%, at least 50 wt.% or at least 55 wt.% of the reinforcing fiber, relative to the total weight of the thermoplastic composite. Additionally or alternatively, the thermoplastic composite includes no more than 90 wt.%, no more than 80 wt.%, no more than 75 wt.%, no more than 70 wt.%, no more than 65 wt.% or no more than 60 wt.% of the reinforcing fiber, relative to the total weight of the thermoplastic composite. In embodiments in which the at least one reinforcing fiber is a plurality of reinforcing fibers, the total concentration of reinforcing fibers is within the ranges above.

The Composites and Composite Fabrication

In the following paragraphs, the term polymer matrix can be replaced by the term non- crosslinked polyamide in the case of the concentration of the non-crosslinked polyamide in the polymer matrix is equal to 100% relative to the total weight of the matrix composition.

The composites include the reinforcing fiber impregnated with the polymer matrix. In some embodiments, the composites can be unidirectional composites. In other embodiments, the composite can be a multidirectional composite, in which the fibers have a more complex structure.

With respect to unidirectional composites (e.g. tapes), the orientation of the reinforcing fibers within the polymer matrix material is generally aligned along the length of the reinforcing fibers (the longest dimensions of the fiber). Unidirectional composites are also sometimes referred to as composite tapes. Fig. 1 is a schematic depiction showing a perspective view of an embodiment unidirectional composite. Referring to Fig. 1, tape 100 includes reinforcing fibers 102 and polymer matrix 104. Reinforcing fibers 102 are generally aligned along their length. Dashed lines 106 (not all labelled, for clarity) denote the orientation of continuous reinforcing fibers 102. As used herein, generally aligned fibers are oriented such that at least 70%, at least 80%, at least 90% or at least 95% of the reinforcing fibers have length that is within 30 degrees, within 25 degrees, within 20 degrees, within 15 degrees, or within 10 degrees along a length of one of the fibers.

In other embodiments, the composite can be a multidirectional composite (e.g. laminate). As noted above, unidirectional composites have fibers that are generally aligned along a single direction. Because the tensile strength of the composite is greater along the length of the fiber, unidirectional composites have excellent tensile strength along a single dimension, and reduced tensile strength along other (e.g. perpendicular) directions. In contrast, multidirectional composites have reinforcing fibers aligned along multiple dimensions and, therefore, have improved tensile strength in multiple dimensions (e.g. more isotropic). In such embodiments, the reinforcing fibers in the polymer matrix can be arranged as a woven fabric or a layered fabric or any combination of one or more therefore. Fig. 2 is a schematic depiction showing a perspective view of an embodiment of a multidirectional composite in which the reinforcing fibers are oriented as a woven fabric. Referring to Fig. 2, multidirectional composite 200 includes polymer matrix 206 and reinforcing fibers 202 and 204, which are generally perpendicular to each other. For clarity, not all reinforcing fibers are labelled in Fig. 2. In some embodiments, each reinforcing fibers 202 and 204 can include bundle of reinforcing fibers. For example, in some embodiments, reinforcing fibers 202 and 204 can be a yarn or layer (e.g. a planar distribution of single reinforcing fibers adjacent each other) of reinforcing fibers. Fig. 3 is a schematic depiction showing a perspective view of an embodiment of a multidirectional composite in which the continuous reinforcing fibers are oriented as a layered fabric. Referring to Fig. 3, multidirectional composite 300 includes reinforcing fibers 302 and 304 and polymer matrix 306. For clarity, not all reinforcing fibers 304 are labelled. Reinforcing fibers 302 and 304 are present in polymer matrix 306 as different layers, with the reinforcing fibers 302 generally aligned parallel with each other and reinforcing fibers 304 generally aligned parallel with each other. Reinforcing fibers 302 are also generally aligned at an angle with reinforcing fibers 304. Dashed lines 308 indicate the alignment of fiber 304 within the multidirectional composite 300. Pluses (“+”) 310 indicate the alignment of fibers 302 within multidirectional composite 300. For clarity, not all fibers 302 and 304 are indicated with dashed lines or pluses. In some embodiments, the angle between fibers 302 and 304 along their respective lengths is at least 15 degrees, at least 30 degrees or at least 40 degrees and no more than about 75 degrees, no more than about 60 degrees or no more than about 50 degrees. Of course, the layered fabric can have additional layers of reinforcing fibers, aligned at the same angle or different angles as the reinforcing fibers in another layer in the multidirectional composite.

The composites can be fabricated by methods well known in the art. In general, regardless of the type of method, composite fabrication includes impregnation of the reinforcing fibers with the polymer matrix material (“melt impregnation”), and subsequent cooling to room temperature (20° C to 25° C) form the final solid composite. The melt impregnation includes contacting the reinforcing fibers with a melt of the polymer matrix material. To make the polymer matrix material processable, the melt is at a temperature of at least Tm* to less than Td*, where Tm* is the melt temperature of the non-crosslinked polyamide in the polymer matrix having the highest melt temperature and Td* is the onset decomposition temperature of the non-crosslinked polyamide having the lowest onset decomposition temperature in the melt. In some embodiments, melt impregnation can further include mechanical compression of the melt against the fibers. For example, in thermo pressing, the polymer matrix material is heated to form a melt and mechanically compressed against the fibers simultaneously. In other melt impregnation embodiments incorporating mechanical compression, the fibers can first be contacted with the melt and subsequently mechanically compressed. Subsequent to melt impregnation, the impregnated reinforcing fibers are cooled to form a solid composite. In some embodiments, the composite can be shaped to a desired geometry prior to be cooled to room temperature. In some such embodiments, subsequent to melt impregnation or prior to or during cooling, the impregnated reinforcing fibers can be passed through a die to form the composite having the desired geometry.

One example of a composite fabrication method includes a slurry process. In a slurry process, a slurry is formed by adding the polymer matrix, in powdered form, to a liquid medium to create a suspension. The slurry is coated onto a surface of the fibers, for example, by passing the fibers through a bath of the slurry. Subsequently, the coated fibers are then heated and consolidated (e.g. by heated mechanical rollers). Slurry fabrication can be desirable for the formation of composite tapes. Another example of a composite fabrication method involves direct powder deposition. In such a method, the polymer matrix, in powder form, is deposited onto the surface of the fibers and subsequently heated to melt the polymer matrix. Direct powder deposition can be desirable to form woven fabric compositions.

In some embodiments, composited can be formed by thermopressing of a two or more composites. In such embodiments, two or more composites can be thermo-pressed (e.g. heated and mechanically pressed together) to form a new composite. For example, referring to Fig. 3, composite 300 can be formed by thermopressing two unidirectional composites (e.g. composite 100), oriented such the reinforcing fibers of each composite are at the desired angle to one another. As another example, referring to Fig. 2, one or more composites according to composite 200 can be pressed together to form another composite. In some such embodiments, prior to thermopressing, each composite can be oriented to achieve the desired relative fiber alignment between each of the composites being thermopressed.

In some embodiments, the composite can be overmolded with another polymer composition. In some such embodiments, a polymer composition including reinforcing fibers can be injection molded onto a portion of the composite. In such embodiments, the reinforcing fibers generally have a length of less than 5 mm. In one embodiment, a polymer composition including a polyamide and reinforcing glass or carbon fibers can be injection molded onto at least a portion of the thermoplastic composite. The polyamide can be an amorphous or semi-crystalline polyamide, preferably a semi-crystalline polyamide.

Articles

The thermoplastic composites described herein can be desirably incorporated into articles for use in a wide variety of application settings. With respect to automotive applications, the thermoplastic composites can be integrated into automotive components including, but not limited to, pans (e.g. oil pans), panels (e.g. exterior body panels, including but not limited to quarter panels, trunk, hood; and interior body panels, including but not limited to, door panels and dash panels), side -panels, mirrors, bumpers, bars (e.g., torsion bars and sway bars), rods, suspensions components (e.g., suspension rods, leaf springs, suspension arms), and turbo charger components (e.g. housings, volutes, compressor wheels and impellers). The thermoplastic composites described herein can also be desirably integrated into aerospace components, oil and gas drilling components (e.g. downhole drilling tubes, chemical injection tubes, undersea umbilicals and hydraulic control lines) and mobile electronic device components. Should the disclosure of any patents, patent applications, and publications which are incorporated herein by reference conflict with the description of the present application to the extent that it may render a term unclear, the present description shall take precedence.

EXAMPLES

The following examples demonstrate the formation and structural integrity of continuous fiber reinforced composites comprising a non-crosslinked polyamide and continuous carbon fibers.

For the preparation of the polyamide, the following starting materials were used:

Isophthalic acid, 99%, from Sigma-Aldrich.

4,4 '-Trimethylenedi piperidine, 97%, from Sigma-Aldrich.

For determining the properties of the obtained polyamide, the following methods were used:

^■ Thermogravimetric Analysis (TGA)

The TGA experiments were performed on raw samples in order to obtain a degradation temperature (T_d) at 1% mass loss which constitutes an important parameter to be considered for the DSCs. Mass loss was measured for each sample by increasing the temperature from 30 °C to 600 °C, with 10 ⁰ C/min under air flow (presence of oxygen).

^■ Differential Scanning Calorimetry (DSC)

The glass transition temperatures (Tg) were measured using a DSC of the company TA instruments.

The DSC analysis was carried out in 3 cycles as follows:

- Cycle 1: -l0°C to 350°C, l0°C/min

- Cycle 2: 350°C to l0°C

- Cycle 3: l0°C to 350°C (Tg)

^■ Tensile Properties

Bars were injected from the previously dried polymer granules to obtain test pieces for mechanical tests.

The tensile tests were carried out according to the ISO 527-2 standard corresponding to tensile tests on thermoplastic test pieces as follows:

- dumbbell tube type 5A,

- zeroing of the force sensor, - placing the test piece in the jaws,

- clamping the jaws,

- set a zero force (by moving the crossbar) to neutralize the forces (tension / compression) that occur during tightening,

- start the test,

- once the pretension is reached (O.lMPa), position the extensometer by contact (L0: 20mm),

- removal of the sample at 2% deformation; the deformations of the specimen are then determined with the traverse displacement (corrected by a factor k, determined before the removal of the extensometer),

- stop the test when the test piece breaks.

Traverse speed during the determination of the module was lmm/min.

Module was between 0.05 and 0.25% deformation.

Test speed after the module was 50mm/min.

Carboxylic acid end-groups (CEG) concentration and amine end-groups (AEG) concentration were determined by potentiometric titration (unit: meq/kg).

The Production of a polyamide TMDP.I

The polyamide was prepared by polycondensation in the melt in a stirred pressure autoclave. 63.41 g (0.38 mol) of isophthalic acid and 82.39 g (0.39 mol) of 4,4'- Trimethylenedipiperidine were poured with 61.0 g of demineralized water, 0.012 g of phosphoric acid 85% and antifoam in a stainless steel clave. The clave atmosphere was purged with nitrogen, and the temperature was increased progressively to 220°C, with continuous stirring, letting pressure increase up to about 17.5 bar. The temperature was increased progressively up to 250°C, while maintaining the same level of pressure. The pressure was then progressively released while the temperature was increased to about 288°C. Vacuum was then applied to reach 500 mbar and kept for 30 min at the same temperature under continuous stirring. The vacuum was broken with nitrogen and the polymer was extruded in a strand. A glassy polymer was obtained which contained polyamide chains represented by the following formula:

wherein n denotes the mole fraction of the polyamide repeating unit. The polymer thus obtained had the following analytical data:

The amorphous had, at a relative humidity of zero (RHO), a glass transition temperature Tg = 119 ⁰ C, measured in DSC according to the protocol described above; and a thermal degradation Td = 380 ⁰ C, measured according to the protocol described above.

End-groups titrations were as follow: CEG = 146 meq/kg, AEG = 103 meq/kg, corresponding to an estimated Mn of 8050 g/mol.

The mechanical properties of this TMDP.I were measured according to the conditions defined above after injection of specimen injected under the conditions described above. Under these conditions, the TMDP.I showed tensile behavior ductile with an elastic modulus (E) of 32lOMPa, an ultimate elongation of 7%.

This TMDP.I has a viscosity at 100 rad/s= 99Pa.s at 340°C, measured with a rheometer ARES-G2 (cone/plate geometry, RH < lOOOppm).

Number average molecular weight (Mn) and weight- average molecular weight (Mw) have been also determined by Size Exclusion Chromatography and Polydispersity Index (PI=Mw/Mn) has been calculated. Size Exclusion Chromatography for measuring absolute molecular weights is performed in Hexafluoroisopropanol (HFIP) with 25 mM sodium trifluoroacetate (0.225 % w/w sodium trifluoroacetate in HFIP) as a solvent at 40°C, followed by refractometry RI. The system was calibrated using the set of narrow polydisperse PMMA standard samples.

Composite Fabrication

The polyamide was ground using a standard laboratory mill. The powder was spread in between layers of woven carbon fiber fabric (HexForce^® 43193, T300 3K 40A C4, taffeta, l93g/m², 450x500mm, desized, from Hexcel) which was sandwiched between two 2 mm stainless steel plates. A polyimide film (commercially available as Kapton^® from DuPont USA) was placed on each side between the stainless steel plate and the fabric/resin. Thermoplastic composite (as laminate) with 10 layers of woven carbon fiber is prepared following the method described below, the amount of polymer in powder form being arranged to obtain, after manufacture of the plate, a fiber / reinforcement volume ratio of 50/50% vol.

The composite plate was manufactured using a PEI 100T thermocompression press according to the following cycle: the preform is introduced cold into the PEI press and then the plate is heated to a speed of 20°C / min at 300°C and then at l0°C / min up to 340°C, once at 340°C, this temperature is maintained 15 minutes before cooling until reaching 60°C. Once extracted from the press, the temperature of the plate decreases until ambient temperature in the open air. With regard to the pressure cycle, as soon as the press closes, the pressure is set at 0.9 bar until the temperature reaches 340°C, the pressure is maintained at 0.9 bar for a few minutes and then gradually increased to reach 3 bar and finally 6 bar. At the time of the beginning of the cooling and until before the opening and extraction of the plate of the press, the pressure is maintained at 6 bars.

After the cycle and cooling to room temperature, the laminates were removed and analyzed for cracks.

Measurement of Properties

To determine the presence of cracking in the composites, the laminates were cut using wet-saw and 20x20 mm specimens were taken for microscopy evaluation. The specimens were imbedded in epoxy mounts with the specimen perpendicular to the mount surface. The mount was then polished according to standard procedures for microscopy sample preparation. Once the desired surface quality was achieved, the specimens were examined under optical microscope with different magnifications. Results

Sample parameters, property measurements and crack testing results are displayed in the following Table 2, below.

Referring to Table 2, composites sample did not exhibit cracking and porosity.

Claims

1. A thermoplastic composite comprising a non-crosslinked polyamide and non- continuous and/or continuous fibers, wherein the polyamide comprises structural units of formula (1):

2. The thermoplastic composite according to claim 1, wherein the non-continuous and/or continuous fibers are glass or carbon fibers.

3. The thermoplastic composite according to claim 1, wherein the polyamide comprises structural units of formula (2):

R 2 and R 3 are independently a bond or an organic divalent residue.

4. The thermoplastic composite according to claim 2, wherein R¹ is hydrogen or a linear, branched, cyclic and/or aromatic Ci_-3o hydrocarbon residue which optionally forms a ring together with R , and R and R are independently a bond or a linear, branched, cyclic and/or aromatic Ci_-3o hydrocarbon residue.

5. The thermoplastic composite according to claim 2 or 3, wherein R¹ is hydrogen or a Ci-₆ alkyl residue which optionally forms a ring together with R , R is a bond or a linear, branched and/or cyclic Ci_-24 alkyl residue, preferably a bond or a linear Ci_-24 alkyl residue, and R is a bond, a Ci_₆ alkylaryl residue or an aryl residue, preferably a bond or a phenyl residue.

6. The thermoplastic composite according to any one of the preceding claims in which the polyamide is a homopolymer.

7. The thermoplastic composite according to any one of the preceding claims wherein the polyamide is obtainable by polymerization of a diamine of formula (3):

wherein R 1 and R 2 are defined as in any one of claims 2 to 4, with an aromatic dicarboxylic acid, ester or halogenide of formula (4):

wherein R is defined as in any one of claims 2 to 4 and X is hydroxy, halogen, Ci_₆ alkoxy or C_6-2o aryloxy.

8. The thermoplastic composite according to any one of the preceding claims wherein the diamine has the formula (5):

wherein R is as in any one of the preceding claims.

9. The thermoplastic composite according to any one of the preceding claims wherein the diamine has the formula (6):

wherein R⁴ is a bond or a linear, branched and/or cyclic Ci_₂₄ alkyl residue, preferably a bond or a linear Ci_₂₄ alkyl residue.

10. The thermoplastic composite according to any one of the preceding claims wherein the diamine has the formula (7):

wherein n is an integer of 0 to 24, preferably 0 to 16, more preferably 3 to 16.

11. The thermoplastic composite according to any one of the previous claims wherein in the aromatic dicarboxylic acid or ester of formula (4) R is a bond or aryl, preferably a bond or phenyl.

12. The thermoplastic composite according to any one of the previous claims wherein the diamine is selected from 4,4'-bipiperidine, 4,4'-ethylenedipiperidine, 4,4'- trimethylenedipiperidine, 4-aminopiperidine, 4-(aminomethyl)piperidine, 2- (aminomethyl)piperidine, 3-(aminoethyl)piperidine, and 4-(aminobutyl)piperidine and the aromatic dicarboxylic acid is selected from isophthalic acid, terephthalic acid, diphenic acid, and biphenyl-4, 4'-dicarboxylic acid; preferably wherein the diamine is selected from 4,4'-trimethylenedipiperidine and 4-aminopiperidine and the aromatic dicarboxylic acid is selected from isophthalic acid, terephthalic acid and diphenic acid.

13. The thermoplastic composite according to any one of the preceding claims in which the polyamide has a number average molecular weight (Mn) lower than 7,000 g/mol.

14. The thermoplastic composite according to any one of the preceding claims in which the polyamide has a number average molecular weight (Mn) comprised from 2,500 to 12,000 g/mol.

15. The thermoplastic composite according to any one of the preceding claims in which the polyamide has a degree of crystallinity in the range of 1 to 85%.

16. The thermoplastic composite according to any one of the preceding claims in which the polyamide comprises an amount of repeating units of formula (1), comprising at least one amide bond, from 2 to 100% relative to the total number of repeating units in the polyamide.

17. The thermoplastic composite according to any one of the preceding claims in which the polyamide comprises an amount of diamine of formula (3) comprised from 2 to 100 mol %, relative to the total amount of diamine monomers in the polyamide.

18. The thermoplastic composite according to any one of the preceding claims in which the polyamide comprises an other diamine of formula H2N-R-NH2 wherein R is an aliphatic, an aromatic, an arylaliphatic or an alkylaromatic radical.

19. The thermoplastic composite according to any one of the preceding claims in which the polyamide comprises also at least one dicarboxylic acid.

20. The thermoplastic composite according to any one of the preceding claims in which the polyamide comprises recurring units derived from:

TMDP.T (trimethylenedipepiridine, terephtalic acid)

TMDP.I (trimethylenedipepiridine, isophthalic acid)

TMDP.DA (trimethylenedipepiridine, diphenic acid)

TMDP.T/ 6T (trimethylenedipepiridine, terephtalic acid, hexamethylene diamine) TMDP.I/ 61 (trimethylenedipepiridine, isophthalic acid, hexamethylene diamine) TMDP.T / 9T (trimethylenedipepiridine, terephtalic acid, nonanediamine)

TMDP.I / 91 (trimethylenedipepiridine, isophthalic acid, nonanediamine)

TMDP.T / 10T (trimethylenedipepiridine, terephtalic acid, decanediamine)

TMDP.I / 101 (trimethylenedipepiridine, isophthalic acid, decanediamine)

TMDP.T/TMDP.6 (trimethylenedipepiridine, terephtalic acid, adipic acid)

TMDP.I/TMDP.6 (trimethylenedipepiridine, , isophthalic acid, adipic acid)

TMDP.T/TMDP.10 (trimethylenedipepiridine, terephtalic acid, sebacic acid)

TMDP.I/TMDP. 10 (trimethylenedipepiridine, isophthalic acid, sebacic acid)

21. The thermoplastic composite according to any one of the preceding claims, wherein the polyamide is contained in a polymer matrix.

22. The thermoplastic composite according to claim 21, wherein the concentration of the polyamide in the polymer matrix is at least 50 wt.%, at least 60 wt.%, at least 70 wt.% at least 80 wt.%, at least 90 wt.%, at least 95 wt.% or at least 99.5 wt.%, or equal to 100 wt.%, relative to the total weight of the matrix composition.

23. The thermoplastic composite according to claim 21 or 22, wherein the concentration of the polymer matrix is at least 10 wt.%, at least 20 wt.%, at least 25 wt.%, at least 30 wt.%, at least 35 wt.% or at least 40 wt.%, relative to the total weight of the composite.

24. The thermoplastic composite according to any one of the preceding claims comprising continuous fibers.

25. The thermoplastic composite according to any one of the preceding claims wherein the concentration of the fibers is at least 20 wt.%, at least 25 wt.%, at least 30 wt.%, at least 35 wt.%, relative to the total weight of the thermoplastic composite.

26. An article comprising the thermoplastic composite according to any one of the preceding claims, wherein the article is selected from the group consisting of an automotive component, an aerospace components, oil and gas drilling components and a mobile electronic device components.

27. A method for making the thermoplastic composite of any one of claims 1 to 25, the method comprising:

(i) impregnating the fibers with the polyamide in melt,

(ii) cooling the impregnated fibers to room temperature.