文献类型：期刊文献

英文题名：Depolymerization kinetics for thermoplastic polyurethane elastomer degradation in subcritical methanol

作者：Liu, Lu[1];Zhu, Zibin[1];Wu, Yongqiang[1]

机构：[1]East China Univ Sci & Technol, Dept Chem Engn, Shanghai 200237, Peoples R China

年份：2017

卷号：140

起止页码：126

外文期刊名：POLYMER DEGRADATION AND STABILITY

收录：;EI(收录号：20171803626345);WOS:【SCI-EXPANDED(收录号:WOS:000405880000014)】；

语种：英文

外文关键词：Polyurethane degradation; Subcritical methanol; Block copolymer; Sectionalized breakage; Continuous distribution kinetics; Activation energies

摘要：The depolymerisation kinetics of thermoplastic polyurethane elastomer (TPU) in subcritical methanol was investigated. The molecular weight distributions (MWDs) of the samples were measured with gel permeation chromatography (GPC) and analysed through Origin 8.5 peak fit module, and continuous distribution kinetics was employed to describe the degradation procedure. Experimental and modelling results indicated that the degradation procedure was two stage owing to the existence of weak linkages between soft and hard domains. During degradation, weak linkages primarily completed the fracture, and strong linkages underwent scission throughout the process. The fracture of TPU chain involved random and chain-end scissions. With continuous distribution kinetics, random scission was divided into two stages by the time when weak linkages were totally disrupted. The activation energies in stages 1 and 2 were 181 and 241 kJ/mol. Chain-end scission was only related to strong linkages. The activation energies of the three kinds of monomers--4,4'-methylene diphenyl carbamate (MDC), 1,4-butanediol (BDO) and dimethyl adipate (DMA) were 137.0, 122.5 and 224.9 kJ/mol, respectively. (C) 2017 Published by Elsevier Ltd.