摘要
采用凝胶渗透色谱(GPC)和计算模拟研究了聚氧化乙烯(PEO)水溶液在温度为20?40°C时的光降解行为,考察了分子链平均断裂次数与每g PEO分子链断裂次数随辐照时间的变化,建立了数均分子量随辐照时间的变化与降解速率常数之间的关系式,并通过Python软件模拟分子链断裂过程。结果表明:分子链平均断裂次数与每g PEO分子链断裂次数均随温度升高而增多,与辐照时间呈线性关系。PEO水溶液降解过程活化能为19.8 kJ/moL随机降解分子量分布系数不随时间发生变化,中间降解分子量分布系数随时间变化逐渐降低。与GPC测试结果对比,表明PEO降解符合中间降解机理。
The photodegradation behavior of poly(ethylene oxide)(PEO)aqueous solution from 20°C to 40°C was studied by Gel permeation chromatograph(GPC)and computational simulation.The number of average chain scission and the number of scission events per gram of irradiation time was investigated.The relationship between the change of number average molecular weight with irradiation time and the degradation rate constant was established.The process of molecular chain scission was simulated by Python.The results show that the number of average chain scission and the number of scission events per gram increases with temperature increase,and showed a linear relationship with irradiation time.The activation energy of PEO degradation in aqueous solution is 19.8 kJ/mol.The Polymer dispersity index(PDI)of random chain scission did not change with time,but the PDI of intermediate chain scission decreased with the time.Compared with GPC results indicates that PEO photodegradation accords with the intermediate chain scission mechanism.
作者
徐玄之
刘婷婷
柴延军
孔猛
罗勇
XU Xuanzhi;LIU Tingling;CHAI Yanjun;KONG Meng;LUO Yong(Shanghai Key Laboratory of Catalysis Technology for Polyolefins,Shanghai 200062,China;State Key Laboratory of Polyolefins and Catalysis,Shanghai 200062,China;Shanghai Research Institute of Chemical Industry,Shanghai 200062,China)
出处
《应用技术学报》
2020年第1期16-21,共6页
Journal of Technology
基金
上海市科委青年科技启明星项目(19QB1402600)资助。
关键词
聚氧化乙烯
光降解
计算模拟
中间断裂机理
PEO
photodegradation
computational simulation
intermediate chain scission mechanism
作者简介
徐玄之(1992-),女,硕士,主要研究方向为高分子材料降解。E-mail:XuxuanZhi_hg@163.com;通信作者:罗勇(1974-),男,博士,教授级高工,主要研究方向为工业催化、精细有机。E-mail:luoyongno.1@163.com。
