Gutiérrez-Silva K, Capezza Antonio J, Gil-Castell O, Badia-Valiente J D
Research Group in Materials Technology and Sustainability (MATS), Department of Chemical Engineering, School of Engineering, University of Valencia, Av. Universitat s/n, 46100 Burjassot, Spain.
Fibre and Polymer Technology Department, KTH Royal Institute of Technology, Teknikringen 56, SE-100 44 Stockholm, Sweden.
Polymers (Basel). 2025 Apr 25;17(9):1173. doi: 10.3390/polym17091173.
The environmental impact of conventional plastics has spurred interest in biopolymers as sustainable alternatives, yet their performance under abiotic degradation conditions still remain unclear. This study investigated the effects of ultraviolet C (UV-C) irradiation and its combination with water immersion (UV-C/HO) on films of commercial poly(butylene adipate--terephthalate)-thermoplastic starch (PBAT/TPS) blends. Changes in structural, chemical, morphological, and thermal properties, as well as molar mass, were analyzed. The results showed distinct degradation mechanisms during exposure to UV-C irradiation either in dry or during water-immersion conditions. UV-C irradiation disrupted PBAT ester linkages, inducing photodegradation and chain scission, leading to a more pronounced molar mass decrease compared to that under water immersion, where a more restrained impact on the molar mass was ascribed to diffuse attenuation coefficient of irradiation. Nevertheless, under UV-C/HO conditions, erosion and disintegration were enhanced by dissolving and leaching of mainly the TPS fraction, creating a porous structure that facilitated the degradation of the film. Blends with higher TPS content exhibited greater susceptibility, with pronounced reductions in PBAT molar mass. In conclusion, exposure of films of PBAT/TPS blends to ultraviolet/water-assisted environments effectively initiated abiotic degradation, in which fragmentation was accentuated by the contribution of water immersion.
传统塑料对环境的影响激发了人们对生物聚合物作为可持续替代品的兴趣，然而它们在非生物降解条件下的性能仍不明确。本研究调查了紫外线C（UV-C）辐照及其与水浸（UV-C/HO）相结合对商用聚己二酸丁二醇酯-对苯二甲酸丁二醇酯-热塑性淀粉（PBAT/TPS）共混物薄膜的影响。分析了结构、化学、形态和热性能以及摩尔质量的变化。结果表明，在干燥或水浸条件下暴露于UV-C辐照期间存在明显的降解机制。UV-C辐照破坏了PBAT酯键，引发光降解和链断裂，导致与水浸条件下相比摩尔质量下降更为明显，在水浸条件下对摩尔质量的影响更为有限，这归因于辐照的扩散衰减系数。然而，在UV-C/HO条件下，主要是TPS组分的溶解和浸出增强了侵蚀和崩解，形成了促进薄膜降解的多孔结构。TPS含量较高的共混物表现出更大的敏感性，PBAT摩尔质量显著降低。总之，PBAT/TPS共混物薄膜暴露于紫外线/水辅助环境中有效地引发了非生物降解，其中水浸的作用加剧了碎片化。
