Ring-Opening Polymerization of Allyl-Functionalized Lactams

Aliphatic polyamides containing pendent allyl groups were prepared by anionic ring-opening copolymerization of ε-caprolactam with monomer 1, the substituted lactam 3-(3-propenyl)-2-azepanone. Copolymerization experiments revealed that up to 11 mol % of 1 was integrated successfully into these novel polyamides, which ranged in molecular weight from 27 to 72 kDa. Relative to the well-known commercial polyamide-6 (PA-6), the degree of crystallinity of the copolymers decreased with incorporation of functional monomer. Moreover, the pendent allyl groups afforded rapid access to numerous functional aliphatic polyamides, using photoinitiated thiol–ene chemistry, providing a pathway to cross-linked polyamide films and gels.