GB916093A - Production of polyamides - Google Patents

Abstract

A process for the production of polyamides comprises heating a monomeric cyclic amide having at least 5 atoms in the ring under substantially anhydrous conditions in the presence of (a) a catalytic amount of an organo-magnesium compound and (b) up to 5 mol. per cent based on the cyclic amide, of a compound containing at least one tertiary nitrogen atom, one group attached to the tertiary nitrogen atom being a carbonyl, thiocarbonyl or sulphonyl group, and a second group being a carbonyl, thiocarbonyl, sulphonyl or nitroso group, the compound being free from primary amino groups. Specified cyclic amides are pyrrolidone, piperidone, S -caprolactam and cyclic monomeric hexamethylene adipamide. Specified organo-magnesium compounds include those made by the reaction of a Grignard reagent with the cyclic amide, a non-cyclic amide or a primary amine. Specified compounds containing tertiary nitrogen atoms include N-substituted imides, e.g. N-acetyl-2-pyrrolidone, N-substituted cyclic imides of dicarboxylic acids, e.g. N-phenyl succinimide; N-acyl sulphonamides, e.g. N-acetyl-N-ethyl-p-toluene sulphonamide; disulphonamides of primary alkyl and aryl amines, e.g. N:N-di(p-toluene sulphonyl) anilide; N-nitrosocarboxamides, e.g. 2-nitroso-2-pyrrolidone and N-nitroso sulphonamides, e.g. N-nitroso-N-methyl benzene sulphonamide. In the examples, S -caprolactam is polymerized in the presence of N-acetyl caprolactam and:- (1) to (4) phenyl magnesium bromide; (5) and (6) methyl magnesium bromide; (7) diphenyl magnesium; (8) magnesium anilide and (9) the reaction product of ethyl magnesium chloride and hexylamine.