Synthesis and environmental degradation of polyesters based on poly (ε-caprolactone)

Poly (e-caprolactone) (PCL), poly (δ-valerolactone) (PVL), poly (e-caprolactone-co-δ-valerolactone) [P(CL-co-VL)], and poly (e-caprolactone-co-ethylene oxide-co-e-caprolactone) (PCL-PEO-PCL) were synthesized by ring-opening and diol-initiated polymerization of e-caprolactone and δ-valerolactone. The degradation of the samples by chemical hydrolysis and in a soil burial test was evaluated. It was found that PCL, PVL, and P(CL-co-VL) degrade mainly enzymatically. The rate of degradation depends on their molecular weight, chemical structure, composition, and morphology. PCL-PEO-PCL block copolymers exhibit a repelling effect to the microorganisms in the soil, which depends on the molecular weight and relative amount of PEO block in the copolymer.