Influence of ultraviolet irradiation on mechanical properties of starch-filled PLA/PBAT blends

摘要

A^The effects of ultraviolet irradiation on the maximum stress, elongation at break and Vickers hardness for corn starch/PLA/PBAT polymer blends were examined. The stress-strain curves of the corn starch/PLA/PBAT blends were measured using a universal testing machine and a split Hopkinson pressure bar (Kolsky bar) system. In the quasi-static and dynamic compressive tests, the ultraviolet irradiation increased the maximum stress. In the quasi-static tensile tests, the ultraviolet irradiation decreased the maximum stress and the elongation at the break. However, no clear trend in terms of the effects of ultraviolet irradiation duration on the maximum stress, Young's modulus and elongation at the break was seen. The ultraviolet irradiation increased the Vickers hardness. The Vickers hardness increased with increasing irradiation duration. Many cracks were observed in the specimen surfaces irradiated for 30 days. The cracks extended deeply from the specimen surfaces into the specimens. It was found from the results of Fourier Transform Infrared spectroscopy (FT-IR) that the ultraviolet irradiation mainly affected the ester group and the methylene group of PBAT.