| abstract |
A high molecular weight polyester-amide block copolymer is produced by reacting a mixture of lower molecular weight polyester and polyamide in the melt with a carbonyl bislactam, especially carbonyl biscaprolactam. The higher molecular weight block copolymer may be obtained in as short a time as 2 minutes, whereas, at least about 10 minutes is required in a conventional process, under comparable conditions, using a bislactam. |