Department of Polymers and Composites, RISE Research Institutes of Sweden, SE-501 15 Borås, Sweden; Department of Fibre and Polymer Technology, KTH Royal Institute of Technology, SE-100 44 Stockholm, Sweden.
Department of Polymers and Composites, RISE Research Institutes of Sweden, SE-501 15 Borås, Sweden.
Water Res. 2021 Jun 15;198:117123. doi: 10.1016/j.watres.2021.117123. Epub 2021 Apr 6.
Biodegradable polymers have been regarded as a promising solution to tackle the pollutions caused by the wide use of conventional polymers. However, during the biodegradation process, the material fragmentation leads to microplastics. In this work, the formation of microplastics from biodegradable poly (butylene adipate-co-terephthalate) (PBAT) in different aquatic environments was investigated and compared with the common non-biodegradable low-density polyethylene (LDPE). The results showed that a much larger quantity of plastic fragments/particles were formed in all aquatic environments from PBAT than from LDPE. In addition, UV-A pretreatment, simulating the exposure to sunlight, increased the rate of PBAT microplastic formation significantly. The size distribution and shapes of the formed microplastics were systematically studied, along with changes in the polymer physicochemical properties such as molecular weight, thermal stability, crystallinity, and mechanical properties, to reveal the formation process of microplastics. This study shows that the microplastic risk from biodegradable polymers is high and needs to be further evaluated with regards to longer timeframes, the biological fate of intermediate products, and final products in freshwater, estuarine and seawater natural habitats. Especially, considering that these microplastics may have good biodegradability in warmer 20 - 25° water but will most likely be highly persistent in the world's cold deep seas.
可生物降解聚合物被认为是解决传统聚合物广泛使用所造成的污染的一种有前途的解决方案。然而，在生物降解过程中，材料的碎片化会导致微塑料的形成。在这项工作中，研究了可生物降解的聚（己二酸丁二酯-对苯二甲酸酯）（PBAT）在不同水介质中的微塑料形成情况，并与常见的不可生物降解的低密度聚乙烯（LDPE）进行了比较。结果表明，与 LDPE 相比，来自 PBAT 的塑料碎片/颗粒在所有水介质中的数量要多得多。此外，紫外线-A 预处理模拟了阳光的暴露，显著提高了 PBAT 微塑料形成的速度。系统研究了形成的微塑料的尺寸分布和形状，以及聚合物物理化学性质（如分子量、热稳定性、结晶度和机械性能）的变化，以揭示微塑料的形成过程。这项研究表明，可生物降解聚合物的微塑料风险很高，需要进一步评估更长时间内、中间产物的生物命运以及淡水、河口和海水自然生境中的最终产物。特别是考虑到这些微塑料在 20-25°C 的温暖水中可能具有良好的生物降解性，但在世界寒冷的深海中很可能具有高度持久性。
