文献类型：期刊文献

英文题名：Controlling crystal phase transition from form II to I in isotactic poly-1-butene using CO₂

作者：Xu, Yang[1];Liu, Tao[1];Li, Lei[1,2];Li, Da-chao[1];Yuan, Wei-kang[1];Zhao, Ling[1]

机构：[1]E China Univ Sci & Technol, State Key Lab Chem Engn, Shanghai 200237, Peoples R China;[2]SINOPEC Shanghai Res Inst Petrochem Technol, Res & Dev Div Synthet Polymers, Shanghai, Peoples R China

年份：2012

卷号：53

期号：26

起止页码：6102

外文期刊名：POLYMER

收录：;WOS:【SCI-EXPANDED(收录号:WOS:000312821600015)】；

基金：The authors are grateful to the National Natural Science Foundation of China (Grant No. 20976046), National High-tech R&D Program of China (863 Program) (Grant No. 2012AA040211), Innovation Program of Shanghai Municipal Education Commission (11CXY23), Fundamental Research Funds for the Central Universities, State Key Laboratory for Modification of Chemical Fibers and Polymer Materials (Dong Hua University) and Program for New Century Excellent Talents in University (NCET-09-0348).

语种：英文

外文关键词：iPB-1; Crystal phase transition; Mathematical modeling

摘要：Controlling crystal phase transition from modification II to I in isotactic Poly-1-butene (iPB-1) using CO2 is presented in this article. The intrinsic kinetics of CO2-induced phase transition from modification II to I in iPB-1 at 40 degrees C and different CO2 pressures were detected using in situ high-pressure Fourier transform infrared spectroscopy (FTIR) and correlated by Avrami equation. Sorption of CO2 in iPB-1 matrix was measured at 40 degrees C and different CO2 pressures using both FTIR and magnetic suspension balance (MSB) and the diffusivity was determined by Fick's second law. An algorithm combining the CO2 diffusion and induced phase transition was subsequently proposed to calculate the CO2 concentration as well as the phase transition degree in the iPB-1 matrix with different thickness at different saturation time. The calculated phase transition degree in the iPB-1 agreed well with the FTIR results. In addition, the yield stresses of iPB-1 specimens annealed in the air and 6 MPa CO2 at 40 degrees C with different durations were also experimentally investigated. The algorithm was applied to predict the phase transition degree of the iPB-1 specimens. The appropriate CO2 treatment time for getting high yield stress was in consistent with that predicted by the algorithm. (C) 2012 Elsevier Ltd. All rights reserved.