The Effect of Irradiation Sterilization on Poly(Lactic) Acid Films

Ionizing radiation is known to cause the deterioration of polymeric materials. In this study, the goal was to determine the effect of gamma and E-beam radiation on poly(lactic) acid (PLA) film at irradiation dosages of 1 to 30 kGy and on post-irradiated PLA after 9-months storage. The physical, chemical, mechanical, thermal, and permeability properties were investigated. Ionizing radiation of the commercial PLA film resulted in a decrease in molecular weight, crystallization temperature and melting temperature T(c)and T-m, which suggested a degradation of PLA by irradiation. Irradiation had no effect on the color of the PLA film. The surface tension of PLA was decreased by gamma irradiation at dose of 1-10 kGy and E-beam irradiation at dose of 1-5 kGy. A decrease in the tensile strength, break elongation and elastic modulus was found for the gamma and E-beam irradiated PLA. Irradiation resulted in a decrease in water vapor and carbon dioxide permeability of PLA while there was no effect on oxygen permeability.

Automated summary

Ionizing radiation can cause degradation of commercial PLA film, resulting in decreased molecular weight, crystallization temperature, and melting temperature, while the color remains unchanged. Irradiation decreases the surface tension of PLA, as well as the tensile strength, break elongation, and elastic modulus.