Enzymatic and Thermal Degradation of Poly(ε-caprolactone), Poly(d,l-lactide), and Their Blends

The enzymatic degradation of poly(d,l-lactide) (PLA), poly(ε-caprolactone) (PCL), and their blends by Novozym 435 was studied in toluene at 60 °C. Both of the polymers were found to degrade by specific chain end scission. A model based on the continuous distribution kinetics was developed to determine the rate coefficient. The degradation rate coefficient was determined from the time evolution of the specific product. The pyrolytic degradation of these polymers and their blends was also investigated. The presence of PLA did not affect either the thermal or enzymatic degradation of PCL. It was thus concluded that the degradations of the polymers were independent of each other.