原子与分子物理学报2024，Vol.41Issue(4)：43-50,8.DOI:10.19855/j.1000-0364.2024.041007
对苯二甲酸乙二醇酯降解机理密度泛函的理论研究
Density functional theory study on thermal degradation mechanism of ethylene terephthalate
摘要
Abstract
Mechanism degradation of ethylene terephthalate momer was investigated by density functional theory B3P86/6-31 + +G(d,p)method,the possible reaction paths of pyrolysis/hydrolysis/alcoholysis and catalytic degradation were designed,the geometric structures of various intermediates,transition states,and products in-volved in the reaction were optimized,and their frequencies were calculated to gain the thermodynamic and ki-netic parameters.The calculation results show that:When water or methanol is used as a catalyst in the ethylene terephthalate process of thermal degradation,the use water or methanol O-H provides H to the main chain of the ethylene terephthalate ester bond on the carbonyl O atom is form terephthalic acid,and ethyl C off H atoms and(water)hydroxyl(-OH)or(methanol)methoxy group(-OCH3)are combined to form new water or methanol,thereby reducing the reaction energy barriers during the pyrolysis of ethylene terephthalate(251.4 kJ/mol→181.1 kJ/mol(methanol)and 187.5 kJ/mol(water)).When water or methanol is reactant in the ther-mal degradation process of ethylene terephthalate,H in water or methanol O-H is supplied to the carbonyl O at-om of the main chain of ethylene terephthalate to form ethylene glycol.Hydroxy group(-OH)in water or me-thoxy group(-OCH3)in methanol binds to the carbonyl C atom of the carbonyl group of ethylene terephthalate backbone to form terephthalic acid or mono-methyl terephthalate,it further reduces the reaction energy barriers(156.4 kJ/mol(methanol)and 170.1 kJ/mol(water))during the pyrolysis of ethylene terephthalate.In the reaction process,either water/methanol as catalysis or water/methanol as reactants can reduce the reaction ener-gy barrier of the main element step to a certain extent,so that the reaction is easy to proceed.关键词
对苯二甲酸乙二醇酯/密度泛函理论/热解/水解/醇解/催化降解/反应机理Key words
Ethylene terephthalate/Density functional theory/Pyrolysis/hydrolysis/Alcoholysis/Catalytic degradation/Reaction mechanism分类
化学化工引用本文复制引用
周梅,李思佳,徐玮峰,黄金保,罗小松,吴雷..对苯二甲酸乙二醇酯降解机理密度泛函的理论研究[J].原子与分子物理学报,2024,41(4):43-50,8.基金项目
贵州省高等学校特色重点实验室建设项目(黔教合KY字[2021]003) （黔教合KY字[2021]003）
贵州省科学技术基金项目(黔科合基础-ZK[2021]278) （黔科合基础-ZK[2021]278）
