文献类型：期刊文献

英文题名：Effect of Catalyst on the Molecular Structure and Thermal Properties of Isosorbide Polycarbonates

作者：Zhang, Ming[1];Lai, Wenqin[1];Su, Lili[1];Wu, Guozhang[1]

机构：[1]East China Univ Sci & Technol, Sch Mat Sci & Engn, Shanghai Key Lab Adv Polymer Mat, Shanghai 200237, Peoples R China

年份：2018

卷号：57

期号：14

起止页码：4824

外文期刊名：INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH

收录：;EI(收录号：20181605019032);WOS:【SCI-EXPANDED(收录号:WOS:000430155700008)】；

语种：英文

外文关键词：Microcomputers - Hydrogen bonds - Metals - Thermodynamic stability - Catalysts - Glass transition - Metal ions

摘要：The effects of catalyst on the molecular weight, chemical structure, and yellowness of isosorbide-based polycarbonate (ISB-PC) in the melt-transesterification and polycondensation stages were investigated. Results showed that the high steric hindrance and intramolecular hydrogen bonding of the endohydroxyl group (endo-OH) of ISB enabled its reactivity to be lower than that of the exohydroxyl group (exo-OH). We also found that the reactivity of endo-OH with Biphenyl carbonate can be preferentially activated by strong electrophilic catalysts, and that the configuration of the ISB-PC chain strongly depended on the reactivity balance between endo-OH and exo-OH. Various catalysts with different coordinate capacities, acidity coefficients, and radius of metal ion were further tested. Catalysts with a calcium or zinc ion showed a higher reactivity of endo-OH than exo-OH, resulting in a high glass-transition temperature of ISB-PCs. Results suggested as well that the thermal stability of ISB-PC may be correlated to the amount of OH groups at the chain ends, whereas its yellowness mainly arose from 1,4-sorbitan due to the hydrolysis of ISB.