Most of the plastics produced worldwide are finally disposed into the environment, most of them being one-use plastic packaging. Once released, plastics may undergone degradation through several agents, such as solar radiation, mechanical forces, and microbial action. Weathered plastics and microplastics (MPs) collected from the marine environment show considerable physical and chemical differences regarding their pristine counterparts; most notably on their surface, where spectrometric measurements are done. Hence, it is crucial to consider aging for their correct identification and quantification in environmental monitoring. Five of the most common polymers employed worldwide for packaging (LDPE, HDPE, PS, PP and PET) were weathered in a pilot-scale system simulating dry and marine conditions for more than 10 weeks. Aliquots were withdrawn periodically to monitor their weathering processes by means of infrared spectrometry and scanning electron microscopy; their spectra were compared and band ratios calculated. Results showed that an individual study of each polymer is necessary since degradation pathways and products depend on the polymer type. Moreover, including spectra of weathered polymers in the spectral libraries to obtain reliable identifications in microplastics pollution studies was critical.

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风化对海洋环境中常用包装聚合物微塑料化学鉴定的影响

世界范围内生产的大部分塑料最终都会被排放到环境中，其中大部分是一次性塑料包装。一旦被释放，塑料可能会通过多种因素发生降解，例如太阳辐射、机械力和微生物作用。从海洋环境中收集的风化塑料和微塑料 (MP) 与其原始对应物显示出相当大的物理和化学差异；最显着的是在它们的表面，在那里进行光谱测量。因此，考虑老化对于在环境监测中正确识别和量化至关重要。全球用于包装的五种最常见聚合物（LDPE、HDPE、PS、PP 和 PET）在模拟干燥和海洋条件的中试规模系统中风化了 10 周以上。定期取出等分试样以通过红外光谱法和扫描电子显微镜监测其风化过程；比较了它们的光谱并计算了谱带比。结果表明，对每种聚合物进行单独研究是必要的，因为降解途径和产物取决于聚合物类型。此外，在光谱库中包括风化聚合物的光谱以在微塑料污染研究中获得可靠的鉴定是至关重要的。