Abstract: The present invention relates to a process for treating an object comprising a first material and a second material bound to the first material by centrifugal force.

Abstract: The invention relates to a process for producing aromatic polyimides, comprising the following steps: (a) preparation of one or more solid salt(s) by reacting one or more aromatic tetracarboxylic acid(s) and one or more diamine(s) according to a mole ratio ranging from 0.95 to 1.05; (b) drying of the solid salt(s), (c) addition, to the dry salt resulting from step (b), of one or more compound(s) (C) comprising one or more group(s) chosen from a carboxylic acid group, an anhydride group, an ester group and an acyl chloride group; (d) solid-state polymerization of said solid salt(s) in the presence of the compound(s) (C).

Abstract: The invention relates to a process for producing aromatic polyimides, comprising the following steps: (a) preparation of one or more solid salt(s) by reacting one or more aromatic tetracarboxylic acid(s) and one or more diamine(s) according to a mole ratio ranging from 0.95 to 1.05; (b) drying of the solid salt(s), (c) addition, to the dry salt resulting from step (b), of one or more compound(s) (C) comprising one or more group(s) chosen from a carboxylic acid group, an anhydride group, an ester group and an acyl chloride group; (d) solid-state polymerization of said solid salt(s) in the presence of the compound(s) (C).

Abstract: The present invention relates to thermoplastic polyimides and to the synthesis thereof. The invention relates in particular to a method for manufacturing semi-aromatic thermoplastic polyimides by means of the solid-state polymerization of a solid ammonium carboxylate salt formed from an aliphatic diamine and an aromatic tetracarboxylic acid, thereby enabling powders having controlled particle sizes to be produced.

Abstract: Uses of low molecular mass, non-evolutive polyamide resins for making composite articles are described. Articles obtained from such resins having good mechanical properties, such as rigidity, breaking load, impact resistance, and fatigue behavior in particular, even when the articles are manufactured according to cycles shorter than those usually used, and without any processing before or after the manufacture of the composite articles, are also described.

Abstract: The present invention relates to thermoplastic polyimides and to the synthesis thereof. The invention relates in particular to a method for manufacturing semi-aromatic thermoplastic polyimides by means of the solid-state polymerization of a solid ammonium carboxylate salt formed from an aliphatic diamine and an aromatic tetracarboxylic acid, thereby enabling powders having controlled particle sizes to be produced.

Abstract: Polyamides, e.g., polyhexamethylene adipamide, are continuously produced via the following stages: Stage 1: into and through a reactor, polycondensing a liquid stream which contain the polyamide monomer(s) at a pressure P1 greater than atmospheric pressure, the stream of material at the outlet of the reactor including a vapor phase which contains steam and a liquid phase which at least contains the product of polycondensation; Stage 2: feeding the outlet stream of material into a chamber, evacuating at least a portion of the vapor phase therefrom and recovering at least the liquid phase which at least contains the product of polycondensation, the pressure P2 in the chamber being regulated at a set value such that it is greater than atmospheric pressure and the residence time of said liquid phase in the chamber being less than 5 minutes; and Stage 3: pressure reducing at least the liquid phase which at least contains the stream of polycondensation product recovered during Stage 2.

Abstract: Uses of low molecular mass, non-evolutive polyamide resins for making composite articles are described. Articles obtained from such resins having good mechanical properties, such as rigidity, breaking load, impact resistance, and fatigue behaviour in particular, even when the articles are manufactured according to cycles shorter than those usually used, and without any processing before or after the manufacture of the composite articles, are also described.

Abstract: Polyamides, e.g., polyhexamethylene adipamide, are continuously produced via the following stages: Stage 1: into and through a reactor, polycondensing a liquid stream which contain the polyamide monomer(s) at a pressure P1 greater than atmospheric pressure, the stream of material at the outlet of the reactor including a vapor phase which contains steam and a liquid phase which at least contains the product of polycondensation; Stage 2: feeding the outlet stream of material into a chamber, evacuating at least a portion of the vapor phase therefrom and recovering at least the liquid phase which at least contains the product of polycondensation, the pressure P2 in the chamber being regulated at a set value such that it is greater than atmospheric pressure and the residence time of said liquid phase in the chamber being less than 5 minutes; and Stage 3: pressure reducing at least the liquid phase which at least contains the stream of polycondensation product recovered during Stage 2.