Université Clermont Auvergne, CNRS, SIGMA Clermont , Institut de Chimie de Clermont-Ferrand , F-63000 Clermont-Ferrand , France.
Laboratory of Analysis of Organic Compounds (509), Faculty of Sciences I , Lebanese University , Hadath, Beirut , Lebanon.
Environ Sci Technol. 2018 Oct 2;52(19):11123-11131. doi: 10.1021/acs.est.8b03172. Epub 2018 Sep 13.
Increasing attention is being paid to the environmental fate and impact of plastics and their additives under sunlight exposure. We evaluated the photodegradation of polystyrene (PS) films (∼100 μm) containing brominated flame retardants (BFRs): decabromodiphenylether (BDE-209), tetrabromobisphenol A (TBBPA), and tetrabromobisphenol A-bis (2.3-dibromopropylether) (TBBPA-DBPE). Irradiations were performed in a solar simulator and outdoors. Infrared (IR) analyses indicated an acceleration of the photooxidation rate of fire-retarded PS films compared to pure PS with an enhancement factor of 7 for TBBPA-DBPE and TBBPA, and 10 for BDE-209. The accelerating effect was found to be correlated with the quantum yield for BFR photodegradation and its absorbance in the PS films. The presence of BFRs also modified the PS photooxidation mechanism and resulted in the formation of 14 brominated photoproducts via bromination and oxidation of PS. Furthermore, a drastic increase in chain scissions and loss of molecular weight was revealed by size exclusion chromatography. This enhanced degradation of PS led to significant leaching (15%) of oxidation products from PS films after immersion in water, and to the gas-phase emission of several volatile brominated products. Our findings suggest that fire-retarded plastics may be a source of potentially hazardous contaminants when exposed to sunlight.
人们越来越关注在阳光照射下塑料及其添加剂的环境归宿和影响。我们评估了含有溴系阻燃剂（BFRs）的聚苯乙烯（PS）薄膜（约 100μm）的光降解情况：十溴二苯醚（BDE-209）、四溴双酚 A（TBBPA）和四溴双酚 A-双（2.3-二溴丙基醚）（TBBPA-DBPE）。辐照在太阳模拟器和户外进行。红外（IR）分析表明，与纯 PS 相比，阻燃 PS 薄膜的光氧化速率加快，TBBPA-DBPE 和 TBBPA 的增强因子为 7，BDE-209 的增强因子为 10。发现这种加速作用与 BFR 光降解的量子产率及其在 PS 薄膜中的吸收率有关。BFR 的存在还改变了 PS 的光氧化机制，并导致 PS 通过溴化和氧化形成 14 种溴化光产物。此外，尺寸排阻色谱法揭示了链断裂和分子量损失的急剧增加。这种增强的 PS 降解导致 PS 薄膜在浸入水中后氧化产物的浸出（15%）显著增加，并导致几种挥发性溴化产物的气相排放。我们的研究结果表明，当暴露在阳光下时，阻燃塑料可能成为潜在危险污染物的来源。
