Jiang Qixuan, Li Zhongyu, Cui Ziheng, Wei Ren, Nie Kaili, Xu Haijun, Liu Luo
Beijing Bioprocess Key Laboratory, Beijing University of Chemical Technology, Beijing 100029, China.
Junior Research Group Plastic Biodegradation, Department of Biotechnology and Enzyme Catalysis, Institute of Biochemistry, University of Greifswald, Felix-Hausdorff-Straße 4, D-17487 Greifswald, Germany.
Polymers (Basel). 2021 Aug 15;13(16):2730. doi: 10.3390/polym13162730.
Recalcitrant plastic waste has caused serious global ecological problems. There is an urgent need to develop environmentally friendly and efficient methods for degrading the highly stable carbon skeleton structure of plastics. To that end, we used a quantum mechanical calculation to thoroughly investigate the oxidative scission of the carbon-carbon (C-C) backbone in polyethylene (PE). Here, we studied the reaction path of C-C bond oxidation via hydroxyl radical in PE. The flexible force constants and fuzzy bond orders of the C-C bonds were calculated in the presence of one or more carbocations in the same PE carbon chain. By comparison, the strength of the C-C bond decreased when carbocation density increased. However, the higher the density of carbocations, the higher the total energy of the molecule and the more difficult it was to be generated. The results revealed that PE oxidized to alcohol and other products, such as carboxylic acid, aldehyde and ketone, etc. Moreover, the presence of carbocations was seen to promote the cleavage of C-C backbones in the absence of oxygen.
难降解的塑料垃圾已造成严重的全球生态问题。迫切需要开发环境友好且高效的方法来降解塑料高度稳定的碳骨架结构。为此，我们采用量子力学计算深入研究了聚乙烯（PE）中碳 - 碳（C - C）主链的氧化断裂。在此，我们研究了PE中通过羟基自由基进行C - C键氧化的反应路径。在同一PE碳链中存在一个或多个碳正离子的情况下，计算了C - C键的柔性力常数和模糊键级。相比之下，当碳正离子密度增加时，C - C键的强度降低。然而，碳正离子密度越高，分子的总能量越高，生成也就越困难。结果表明，PE氧化生成醇以及其他产物，如羧酸、醛和酮等。此外，在无氧情况下，碳正离子的存在可促进C - C主链的断裂。
