Journal of Applied Polymer Science, Vol.74, No.7, 1815-1820, 1999
Improvement of processability of poly(epsilon-caprolactone) by radiation techniques
Improvement of processability of Poly(epsilon-caprolactone) (PCL) was achieved by introduction of a branch structure using gamma-irradiation from a Co-60 source. Irradiated PCL has higher molecular weight by producting a branch structure. Hence, the irradiation at a lower dose, such as 3 Mrad, leads to a higher melt viscosity. The branched structure gave improved properties for dynamic viscoelasticit3r and elongational viscosity. High elongational viscosity was observed by entanglement due to branch chain formed during irradiation, and the elongational viscosity for 3 Mrad is higher than 1.5 Mrad. Due to a higher elongational viscosity, PCL foam can be produced by a molding process. Foam produced from irradiated PCL pellets at 3 Mrad has honeycomb-like structure, and the foam showed higher enzymatic degradation compared to film samples.