Thermoplastic copolyimides

A semiaromatic semicrystalline thermoplastic polyimide obtained by polymerization of at least:

• (a) an aromatic compound comprising two anhydride functions and/or carboxylic acid and/or ester derivatives thereof selected from the group consisting of:
• pyromellitic acid, 3,3′,4,4′-biphenyltetracarboxylic acid, 2,3,3′,4′-biphenyltetracarboxylic acid, 2,2′,3,3′-biphenyltetracarboxylic acid, 3,3′,4,4′-benzophenonetetracarboxylic acid, 2,2′,3,3′-benzophenonetetracarboxylic acid, 1,2,5,6-naphthalenetetracarboxylic acid, 2,3,6,7-naphthalenetetracarboxylic acid, 2,3,5,6-pyridinetetracarboxylic acid, 3,4,9,10-perylenetetracarboxylic acid, 3,3′,4,4′-tetraphenylsilanetetracarboxylic acid, 2,2′-bis(3,4-bicarboxyphenyl)hexafluoropropanetetracarboxylic acid;
• and
• (b) a diamine of formula (I) NH2—R—NH2 selected from the group consisting of:
• 1,13-diaminotridecane, 1,14-diaminotetradecane, 1,15-diaminopentadecane, 1,16-diaminohexadecane, 1,17-diaminoheptadecane, 1,18-diaminooctodecane, 1,19-diaminononadecane and 1,20-diaminoeicosane;
• or
• an ammonium carboxylate salt obtained from monomers (a) and (b).

A process for manufacturing a polyimide, comprising polymerizing at least:

• an aromatic compound comprising two anhydride functions and/or carboxylic acid and/or ester derivatives thereof selected from the group consisting of:
• pyromellitic acid, 3,3′,4,4′-biphenyltetracarboxylic acid, 2,3,3′,4′-biphenyltetracarboxylic acid, 2,2′,3,3′-biphenyltetracarboxylic acid, 3,3′,4,4′-benzophenonetetracarboxylic acid, 2,2′,3,3′-benzophenonetetracarboxylic acid, 1,2,5,6-naphthalenetetracarboxylic acid, 2,3,6,7-naphthalenetetracarboxylic acid, 2,3,5,6-pyridinetetracarboxylic acid, 3,4,9,10-perylenetetracarboxylic acid, 3,3′,4,4′-tetraphenylsilanetetracarboxylic acid, 2,2′-bis(3,4-bicarboxyphenyl)hexafluoropropanetetracarboxylic acid;
• and
• a diamine of formula (I) NH2—R-selected from the group consisting of:
• 1,13-diaminotridecane, 1,14-diaminotetradecane, 1,15-diaminopentadecane, 1,16-diaminohexadecane, 1,17-diaminoheptadecane, 1,18-diaminooctodecane, 1,19-diaminononadecane and 1,20-diaminoeicosane;
• or
• an ammonium carboxylate salt obtained from monomers (a) and (b), in particular by polymerization of an ammonium carboxylate salt obtained from monomers (a) and (b).