Semi-crystalline polyamide composition with high glass transition temperature for composite material, process for manufacturing same and uses thereof

A reactive composition suitable for producing a thermoplastic composite material, comprising:

• 30% to 60% by volume of a reactive composition comprising at least two polyamide prepolymers which are reactive with one another and which each respectively bear two identical end functions X′ or Y′, wherein the function X′ of a polyamide prepolymer is capable of reacting with the function Y′ of the other polyamide prepolymer and not capable of reacting with the function X′ of the same polyamide prepolymer, and which produces a semi-crystalline polyamide polymer when subjected to polymerization,
• 40% to 70% by volume of long reinforcing fibers,
• wherein
• the reactive composition impregnates the long reinforcing fibers,
• the reactive polyamide prepolymer comprises at least one BACT/XT copolyamide,
• BACT is a unit comprising an amide unit present at a molar content ranging from 20% to 70%,
• wherein
• BAC is selected from the group consisting of 1,3-bis(aminomethyl)cyclohexyl (1,3-BAC), 1,4-bis(aminomethyl)cyclohexyl (1,4-BAC) and mixtures thereof, and
• T is terephthalic acid,
• XT is a unit comprising an amide unit present at a molar content ranging from 30% to 80%,
• wherein
• X is a C9 to C18 linear aliphatic diamine, and
• T is terephthalic acid,
• in the BACT and/or XT units, independently of one another, up to 30 mol %, relative to the total amount of dicarboxylic acids, of the terephthalic acid may optionally be replaced with other aromatic, aliphatic or cycloaliphatic dicarboxylic acids comprising 6 to 36 carbon atoms, and
• in the BACT and/or XT units, independently of one another, up to 30 mol %, of the BAC and/or where appropriate of X, relative to the total amount of diamines, may optionally be replaced with other diamines comprising from 4 to 36 carbon atoms,
• in the BACT/XT copolyamide, no more than 30 mol %, relative to the total amount of monomers, can be formed by lactams or aminocarboxylic acids,
• the sum of the monomers which replace the terephthalic acid, the BAC and X does not exceed a concentration of 30 mol %, relative to the total amount of monomers in the BACT/XT copolyamide, and
• BACT and XT units are always present in the BACT/XT copolyamide.