Synthesis and biodegradation of poly(2-pyrrolidone-co-ε-caprolactone)s

Copolyesteramides of 2-pyrrolidone with ε-caprolactone were synthesized by ring-opening copolymerization. The copolymers were random-like and their melting temperature and heat of fusion were dependent on the polymer composition. Biodegradation by a polyamide 4 (PA4) degrading microorganism showed rapid degradation in the region of amide-rich polymer composition. On the contrary, enzymatic hydrolysis using a lipase resulted in a different tendency, that is, ester-rich copolymers hydrolyzed rapidly. Activated sludge makes copolymers degrade to CO2 in wide polymer composition ratio. Copolyesteramides are expected to be applied as an environmentally-friendly plastics or bioabsorbable polymers in medical fields.