Centre of Polymer Systems, Tomas Bata University in Zlin, TGM Sqr. 5555, 760 01 Zlin, Czech Republic.
Chemosphere. 2012 Aug;88(10):1214-9. doi: 10.1016/j.chemosphere.2012.03.072. Epub 2012 Apr 23.
Three commercially available biodegradable polymers, two different aromatic-aliphatic copolyesters and polylactic acid, intended for the fabrication of agricultural mulching films, in addition to other applications, were subjected to a series of tests with the aim of studying the relationship between their photooxidation and biodegradation. Photooxidation resulted in the rearrangement of polymeric chains, in the case of both copolyesters the events led to polymeric chain crosslinking and the formation of insoluble polymeric gel. The tendency was significantly more pronounced for the copolyester with the higher content of the aromatic constituent. As regards polylactic acid photochemical reactions were not accompanied by crosslinking but instead provoked chain scissions. A biodegradation experiment showed that, despite marked structural changes, the extent of photooxidation was not the decisive factor, which significantly modified the rate of biodegradation in all three materials investigated. The specific surface area of the sample specimens was shown to be more important.
三种市售的可生物降解聚合物，两种不同的芳香族脂肪族共聚酯和聚乳酸，除了其他应用外，还被用于一系列测试，旨在研究它们的光氧化和生物降解之间的关系。光氧化导致聚合物链的重排，在两种共聚酯的情况下，这些事件导致聚合物链交联和不溶性聚合物凝胶的形成。对于芳香族成分含量较高的共聚酯，这种趋势更为明显。至于聚乳酸，光化学反应没有交联，但引发了链的断裂。生物降解实验表明，尽管结构发生了明显变化，但光氧化的程度不是决定性因素，这显著改变了三种所研究材料的生物降解速率。样品的比表面积被证明更为重要。
