Phase morphology, mechanical performance, and thermal properties of fully biodegradable polylactic acid/polybutylene adipate terephthalate crosslinked network induced by UV irradiation

Abstract Over the past few decades, there has been growing interest in replacing some of the fossil-derived polymers with biobased or biodegradable ones due to environmental concerns. Biobased polylactic acid (PLA) has emerged as the most practical option because of its superior mechanical and thermal qualities compared to other types of biopolymers. However, due to the inherent deficiencies of PLA, modifications to PLA have been an ongoing endeavor. In this study, samples of neat PLA, neat polybutylene adipate terephthalate (PBAT), blends of PLA and PBAT, as well as their crosslinked blends were fabricated. The morphology, mechanical and thermal transition performances, and thermal stability of the fully biodegradable samples were then measured. The results show that the flexibility and toughness of PLA were significantly enhanced. Especially, the elongation at break of ABT-UV30 (PLA/PBAT/triallyisocyanurate (TAIC) exposed to ultraviolet (UV) light for 30 minutes) was increased 37.8 times as compared to neat PLA. The compatibility of PLA and PBAT was enhanced by the development of a crosslinked network structure. The thermalgravimetric analyzer thermograms show that a moderate amount of UV radiation can improve the thermal stability of the sample while an excessive amount of UV radiation can reduce the temperature at which the sample degrades.