Apicella Annalisa, Malafeev Konstantin V, Scarfato Paola, Incarnato Loredana
Department of Industrial Engineering, University of Salerno, Via Giovanni Paolo II n. 132, 84084 Fisciano, SA, Italy.
Polymers (Basel). 2024 Aug 10;16(16):2268. doi: 10.3390/polym16162268.
Biodegradable polymers and their blends have been advised as an eco-sustainable solution; however, the generation of microplastics (MPs) from their degradation in aquatic environments is still not fully grasped. In this study, we investigated the formation of bio-microplastics (BMPs) and the changes in the physicochemical properties of blown packaging films based on polylactic acid (PLA), polybutylene succinate (PBS) and a PBS/PLA 70/30 wt% blend after degradation in different aquatic media. The tests were carried out in two temperature/light conditions to simulate degradation in either warm water, under sunlight exposure (named Warm and Light-W&L), and cold deep water (named Cold and Dark-C&D). The pH changes in the aqueous environments were evaluated, while the formed BMPs were analyzed for their size and shape alongside with variations in polymer crystallinity, surface and mechanical properties. In W&L conditions, for all the films, the hydrolytic degradation led to the reorganization of the polymer crystalline phases, strong embrittlement and an increase in hydrophilicity. The PBS/PLA 70/30 blend exhibited increased resistance to degradation with respect to the neat PLA and PBS films. In C&D conditions, no microparticles were observed up to 12 weeks of degradation.
可生物降解聚合物及其共混物被认为是一种生态可持续的解决方案；然而，它们在水生环境中降解产生微塑料（MPs）的情况仍未被完全了解。在本研究中，我们研究了基于聚乳酸（PLA）、聚丁二酸丁二醇酯（PBS）以及70/30 wt%的PBS/PLA共混物的吹塑包装薄膜在不同水生介质中降解后生物微塑料（BMPs）的形成以及物理化学性质的变化。测试在两种温度/光照条件下进行，以模拟在温暖阳光下的水中（命名为温暖与光照-W&L）以及寒冷深水（命名为寒冷与黑暗-C&D）中的降解情况。评估了水环境中的pH变化，同时分析了形成的BMPs的尺寸和形状，以及聚合物结晶度、表面和机械性能的变化。在W&L条件下，对于所有薄膜，水解降解导致聚合物结晶相的重组、严重脆化和亲水性增加。相对于纯PLA和PBS薄膜，PBS/PLA 70/30共混物表现出更高的抗降解性。在C&D条件下，直至降解12周都未观察到微粒。
