Shi Yanqi, Zheng Lezhou, Huang Hexinyue, Tian Ye-Chao, Gong Zhimin, Liu Peng, Wu Xiaowei, Li Wen-Tao, Gao Shixiang
State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210093, Jiangsu, People's Republic of China.
College of Natural Resources and Environment, Northwest A&F University, Yangling 712100, Shaanxi, People's Republic of China.
Environ Sci Technol. 2023 Feb 7;57(5):1894-1906. doi: 10.1021/acs.est.2c05063. Epub 2023 Jan 24.
Polyurethane (PU) synthetic leathers possess an intricate plastic composition, including polyester (PET) base fabrics and upper PU resin, but the release of fragments from the complexes is unclear. Therefore, we investigated the photodegradation trends of PET base fabrics with PU coating (PET-U) as a representative of composite plastics. Attention was paid to the comparison of the photoaging process of PET-U with that of pure PET base fabric (PET-P). To reveal the potential for chain scission, physical and chemical changes (, surface morphology, molecular weight, and crystallinity) of the two fabrics were explored. The generation of microplastic fibers (MPFs) and microplastic particles (MPPs) was distinguished. Compared with PET-P, PET-U showed a similar but delayed trend in various characteristics and debris release rate as the photoaging time prolonged. Even so, after 360 h of illumination, the generated number of MPs (including MPFs and MPPs) rose considerably to 9.32 × 10 MPs/g, and the amount of released nanoplastics (NPs) increased to 2.70 × 10 NPs/g from PET-U. The suppression of MP formation from PET-U was potentially directed by the physical shielding of the upper PU layer and the dropped MPs, which resisted the photochemical radical effect. The components of dissolved organic matter derived from plastics (P-DOM) were separated by molecular weight using a size-exclusion chromatography-diode array detector-organic carbon detector/organic nitrogen detector (SEC-DAD-OCD/OND), and the results showed that a larger amount of carbon- and nitrogen-containing chemical substances were generated in PET-U, accompanied by more aromatic and fluorescent compounds. The results provided theoretical bases and insights for future research on the risks of plastic debris from PU synthetic leathers on aquatic organisms and indicated feasible directions for exploring combined pollution studies of plastics.
聚氨酯（PU）合成皮革具有复杂的塑料成分，包括聚酯（PET）基布和上层PU树脂，但复合材料中碎片的释放情况尚不清楚。因此，我们研究了以PU涂层PET基布（PET-U）作为复合塑料代表的光降解趋势。重点关注PET-U与纯PET基布（PET-P）光老化过程的比较。为了揭示断链的可能性，探索了两种织物的物理和化学变化（如表面形态、分子量和结晶度）。区分了微塑料纤维（MPFs）和微塑料颗粒（MPPs）的产生。与PET-P相比，随着光老化时间延长，PET-U在各种特性和碎片释放速率方面呈现出相似但延迟的趋势。即便如此，光照360小时后，PET-U产生的微塑料（包括MPFs和MPPs）数量大幅上升至9.32×10个微塑料/克，释放的纳米塑料（NPs）量增加至2.70×10个纳米塑料/克。PET-U中MP形成的抑制可能是由于上层PU层的物理屏蔽作用以及掉落的微塑料抵抗了光化学自由基效应。使用尺寸排阻色谱-二极管阵列检测器-有机碳检测器/有机氮检测器（SEC-DAD-OCD/OND）按分子量分离了源自塑料的溶解有机物（P-DOM）的成分，结果表明PET-U中产生了大量含碳和含氮化学物质，同时伴有更多的芳香族和荧光化合物。这些结果为未来研究PU合成皮革塑料碎片对水生生物的风险提供了理论依据和见解，并为探索塑料联合污染研究指明了可行方向。
