Ring-opening polymerization of s-caprolactone catalyzed by a novel Epase Candida sp. 99-125

摘要

The ring-opening polymerization of ε-caprolactone catalyzed by a novel lipase Candida sp. 99-125 was achieved in organic solvents. ε-Caprolactone was found to be polymerized in quantitative yield in toluene at 80 °C for 5 days. The poly (ε-caprolactone) obtained had a number-average molecular weight of 14,120 (polydispersity index =1.161). The effect of enzyme concentration, temperature, reaction time, reaction medium, and water content on monomer conversion and product molecular weight were investigated. Kinetic analysis showed that the enzyme displayed Michaelis-Menten kinetics and showed stronger affinity for ε-caprolactone (with a K_m value of 6.1 mmol/L) than other reported lipases.