The COVID-19 pandemic has incredibly escalated the use of petroleum-based disposable facemasks, posing a significant environmental burden. In response, polylactide acid (PLA), a biobased and biodegradable aliphatic polymer, has been considered a potential alternative. However, applications of PLA in facemask materials are hindered by its inherent brittleness, poor toughness, and slow degradation rate in the environment. Addressing these challenges, this study explored the use of two biobased triesters as green plasticizers to improve PLA fibrous membranes with desired mechanical properties and biodegradability. PLA and the plasticizers were mixed and electrospun into the fibrous membranes. The influence of two plasticizers in varied contents on the filtration efficiency, morphology, thermal behavior, mechanical properties, and degradation rate of the PLA membranes is systematically investigated. The findings reveal that the proper addition of these plasticizers (7% content) not only effectively lowered the glass transition and cold crystallization temperatures of PLA membranes from 65 to 52 °C and from 78 to 70 °C, respectively, without compromising the filtration performance but also significantly enhanced the material’s toughness, as evidenced by the increased tensile strength from 0.44 to 1.08 MPa and the elongation at break from 1.32% to 12.53%. Furthermore, the plasticized PLA membranes exhibited an enzymatic degradation rate of 34.18% at 50 °C after 96 h, a more than 2-fold increase compared to that of pure PLA. These advancements in this work contribute to the development of high-performance and eco-friendly filtration materials, offering a sustainable solution to the environmental challenges posed by conventional facemasks.

中文翻译：

---

生物基三酯作为增塑剂，可改善作为面罩材料的聚乳酸纤维膜的机械和生物降解性能


COVID-19 大流行极大地增加了以石油为原料的一次性口罩的使用，造成了巨大的环境负担。因此，聚乳酸（PLA），一种生物基且可生物降解的脂肪族聚合物，被认为是一种潜在的替代品。然而，PLA固有的脆性、韧性差、在环境中降解速度慢等问题阻碍了PLA在口罩材料中的应用。为了解决这些挑战，本研究探索使用两种生物基三酯作为绿色增塑剂来改善 PLA 纤维膜，使其具有所需的机械性能和生物降解性。 PLA 和增塑剂混合并静电纺丝成纤维膜。系统研究了两种不同含量增塑剂对PLA膜过滤效率、形貌、热行为、力学性能和降解率的影响。研究结果表明，适当添加这些增塑剂（7%含量）不仅可以有效地将PLA膜的玻璃化转变温度和冷结晶温度分别从65°C降低到52°C和从78°C降低到70°C，而且不会影响过滤性能而且还显着提高了材料的韧性，拉伸强度从 0.44 MPa 增加到 1.08 MPa，断裂伸长率从 1.32% 增加到 12.53%。此外，增塑PLA膜在50℃下96小时后的酶降解率为34.18%，与纯PLA相比增加了2倍以上。这项工作的这些进展有助于高性能和环保过滤材料的开发，为传统口罩带来的环境挑战提供可持续的解决方案。