文献类型：期刊文献

英文题名：Continuous-distribution kinetics for degradation of polybutylene terephthalate (PBT) in supercritical methanol

作者：Huang, Jie[2];Yang, Junhe[1];Chyu, Minking K.[3];Wang, Qingming[3];Zhu, Zibin[2]

机构：[1]Shanghai Univ Sci & Technol, Sch Mat Sci & Engn, Shanghai 200093, Peoples R China;[2]E China Univ Sci & Technol, Sch Chem Engn, Shanghai 200237, Peoples R China;[3]Univ Pittsburgh, Dept Mech Engn & Mat Sci, Pittsburgh, PA 15261 USA

年份：2009

卷号：94

期号：12

起止页码：2142

外文期刊名：POLYMER DEGRADATION AND STABILITY

收录：;EI(收录号：20094612456836);WOS:【SCI-EXPANDED(收录号:WOS:000272624400006)】；

基金：Contract grant sponsor National Natural Science Foundation of the People's Republic of China; contract grant number, 50773040.

语种：英文

外文关键词：Supercritical methanol; Depolymerization; Polybutylene terephthalate; Mechanism; Continuous-distribution kinetics

摘要：The depolymerization of polybutylene terephthalate (PBT) in supercritical methanol was investigated by using a batch autoclave reactor. Continuous kinetics analysis was applied to experimental data. It was observed that PBT could dissolve into supercritical methanol quickly and decompose completely in a homogeneous phase. PBT with average molecular weight of about 29 700 was converted to oligomer with that of 4200 within 10 min and with that of 2700 in 15 min at 513 K and converted into monomer completely within 22 min. The main reaction products decomposed of PBT were dimethylterephthalate (DMT)and 1,4-butanediol (BG) by methanolysis. The yields of monomer components of the decomposition products, including byproducts were measured. The yields of DMT and BG could reach 94.5% and 70.1%, respectively, at 563 K for 75 min. Based on the qualitative and quantitative analyses of the products, a depolymerization-reaction scheme was proposed to explain the reaction mechanism, i.e. the degradation of PBT in supercritical methanol mainly includes random scission and chain-end scission reactions and side reactions for monomer components. With the process of degradation, some oligomers could be decomposed into small molecular products by side reactions. Continuous-distribution kinetics theory was developed to analyze the decomposition behavior. The energy of activation for the random scissions of PBT in the supercritical methanol was 86.53 kJ/mol. (C) 2009 Elsevier Ltd. All rights reserved.