Effect of plasma treatment on accelerated PLA degradation

Poly(lactic acid) (PLA) has been found to be important in various applications, such as in the medical, pharmaceutical, and packaging industries. However, the long-term associated degradation process of PLA is a limiting factor for some applications. Therefore, in this research, the influence of corona and radio-frequency (RF) surface plasma treatment on the degradation of PLA in accelerated weathering tests was studied. The accelerated weathering test was applied using standard UV irradiation for up to 2000 h. The morphological/topographical, chemical, crystallization, mechanical, and thermal changes were analyzed after 500, 1000, and 2000 h of accelerated weathering time. The introduction of the polar functional groups caused by plasma treatment on the PLA surface improved its wettability, and therefore, hydrolytic degradation was promoted over the accelerated weathering time. It was revealed that the plasma treatment enhanced the hydrolytic and UV degradation of the PLA, as was confirmed by investigation of the physical, chemical, mechanical, and thermal properties. Moreover, the RF plasma was more pronounced than the corona plasma in the degradation of the PLA. Such an approach represents a pathway to promote and tailor PLA degradation.