文献类型：期刊文献

英文题名：Effect of molecular weight on CO2-philicity of poly(vinyl acetate) with different molecular chain structure

作者：Hu, Dongdong[1];Zhang, Yingna[1];Su, Mei[1];Bao, Lei[1];Zhao, Ling[1];Liu, Tao[1]

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

年份：2016

卷号：118

起止页码：96

外文期刊名：JOURNAL OF SUPERCRITICAL FLUIDS

收录：;EI(收录号：20163202701088);WOS:【SCI-EXPANDED(收录号:WOS:000383827200011)】；

基金：This work was supported by the National Science Foundation of China (21376087), Research Fund for the Doctoral Program of Higher Education of China (20130074110013), the 111 Project (B08021), and the Fundamental Research Funds for the Central Universities.

语种：英文

外文关键词：Poly(vinyl acetate); CO2-philicity; Molecular chain structure; Cloud point pressure; Molecular dynamics simulations

摘要：The low molecular weight, topological structure and end group removal are expected to enhance the CO2-philicity of poly(vinyl acetate) (PVAc), which is of great interest for expanding CO2 applications as a green solvent. This work aims at investigating the effect of molecular weight (M-n) of PVAc with different molecular chain structure on the CO2-philicity through dissolution behavior measurement and molecular modeling. Well-defined 3-armed and 4-armed R-core PVAc was synthesized by RAFT polymerization, and then the corresponding xanthate groups were removed. The CO2-philicity of multi-armed PVAc was found to be inferior to that of linear one at low M-n. With increasing the M-n from 1000 to 7000 g/mol, the cloud point pressures (P-c) of multi-armed PVAc first decreased, reached a minimum at a given M-n, and then increased, which was different from the variation trend of the Pc of linear PVAc versus M-n. In addition, removal of the xanthate groups could effectively enhance the CO2-philicity of PVAc, especially at low M-n. Moreover, the molecular dynamics (MD) simulations on the interactions in polymer/CO2 systems indicated that the multi-armed structure had different effects on the compatibility with CO2 at different M-n. At low M-n, the polymer polymer interaction was the main driving force deciding the CO2-philicity due to the significant difference in different molecular chain structures. At high M-n, multi-armed structure enhanced the CO2-philicity due to the synergistic effect of moderate polymer polymer interaction and large polymer-CO2 interaction. The appropriate molecular chain structure could be selected to enhance the CO2-philicity of PVAc at a certain M-n. (C) 2016 Elsevier B.V. All rights reserved.