常见微塑料的自然光解老化

Insights into natural photo-aging of common-used microplastics

微塑料是一种新型环境污染物,对生态环境有重要的影响.本研究分析了几种常见塑料产品的主要成分,并探究了自然光解老化前后微塑料红外光谱的变化情况.通过与标准谱图比对,所选塑料样品分别属于聚乙烯(PE)、聚丙烯(PP)和聚对苯二甲酸乙二醇酯(PET).红外结果表明,微塑料老化基本都伴随苯环、羰基与羟基的生成.此外,微塑料自然光解老化后表面发生龟裂,比表面积增加,亲水性增强.微塑料表面结构的变化势必造成微塑料环境行为的改变.因此,探究不同微塑料光解老化过程可以为分析其潜在的环境行为提供理论指导.

Microplastics have been classified as an emerging environmental contaminant,which exhibits great effect on the ecology.In this study,several types of custom plastic products were identified and grinded into microplastics,which were subsequently exposed to solar irradiation for different time.By comparison with infrared spectra of standard plastics,the selected microplastics belong to polyethylene(PE),polypropylene(PP)and polyethylene terephthalate(PET).In addition,infrared spectra were determined for prepared microplastics after exposure to natural solar irradiation.As indicated by the infrared results,oxygen-containing functional groups,e.g.,carbonyl and hydroxyl,could be obtained by photo radiation under ambient condition,which would affect the environmental behaviors of microplastics.Therefore,the investigation of microplastic photo-aging could provide theoretical evidence for the analysis of their potential environmental behaviors.