文献类型：期刊文献

英文题名：Study on the atomic scale of thermal and thermo-oxidative degradation of polylactic acid via reactive molecular dynamics simulation

作者：Li, Chenyang[1];Liu, Qiang[2];Gong, Weiguang[3];Zhou, Zhou[1];Yao, Zhongyang[1];Meng, Xin[1]

机构：[1]East China Univ Sci & Technol, Dept Prod Engn, Shanghai Key Lab Multiphase Mat Chem Engn, Shanghai 200237, Peoples R China;[2]China Acad Engn Phys, Inst Nucl Phys & Chem, Mianyang 621000, Sichuan, Peoples R China;[3]East China Univ Sci & Technol, Res & Dev Ctr Sports Mat, Shanghai 200237, Peoples R China

年份：2022

卷号：709

外文期刊名：THERMOCHIMICA ACTA

收录：;EI(收录号：20220311461025);WOS:【SCI-EXPANDED(收录号:WOS:000754010500003)】；

基金：This work was financially supported by Ningbo Public Welfare Science and Technology Project (NO. 2021S09).

语种：英文

外文关键词：Polylactic acid; Degradation; ReaxFF-MD; Product distribution; Reaction pathway

摘要：The reactive force field molecular dynamics (ReaxFF-MD) simulations were performed on polylactic acid (PLA) for the first time to understand its thermal and thermo-oxidative degradation mechanisms. The main degradation products of PLA observed in actual experiments were well reproduced by ReaxFF-MD simulations. The results showed that the initial thermal degradation pathway for the PLA was the homolytic cleavage of C-O bond next to the ester group, followed by C-O bond breaking in the ester group and C-C bond cleavage. Carbon monoxide, carbon dioxide and acetaldehyde were the major volatile products generated following the thermal degradation after being initiated by the homolytic scission. In thermo-oxidative degradation simulation, the alkyl peroxide and hydroperoxide were formed, which degraded into alkoxyl and hydroxyl radicals, resulting in the increase of the lower carbon fraction (C1-4). This study would provide meaningful theoretical guidance for the mechanisms of thermal and thermo-oxidative degradation of PLA.