| 摘要 |
<p>The invention relates to a process for the preparation of a polyamide comprising at least a step in which a composition that comprises at least (a) a primary aminocarbonamide and (b) an aminocarboxylic acid and/or a lactam is polymerised, said composition comprising at least: (a) 10 - 90 wt.% primary aminocarbonamide; (b) 10 - 90 wt.% aminocarboxylic acid and/or lactam; (c) 0 - 4 wt.% water; the amounts being relative to the sum of the compounds (a+b+c). Preferably the sum of the compounds (a+b+c) is at least 75 wt.% of the total composition, more preferably 85 wt.%, most preferably 90 wt.%. The polyamide obtained with the process has a θrel of more than 2.2. The process is eminently suitable for the preparation of polyamide-6 (polycapronamide) from a composition comprising 6-aminocapronamide, 6-aminocaproic acid and/or ε-caprolactam. This composition is preferably obtained via the reductive amination of a 5-formylvalerate ester, preferably 5-formylmethylvalerate in water. The 5-formylvalerate ester can for example be obtained from butadiene via (a) a carbonylation and (b) a hydroformylation reaction.</p> |
