THERMAL HISTORY DEPENDENCE OF POLYflETHYLENE OXIDE) SOLUTION CRYSTALLIZATION AT CONCENTRATIONS LOSE TO THE OVERLAP LIMIT
(0) Solution polymer crystallization has been widely studied for decades. In general, people put great emphasis on the final morphology and crystal structure. However, the details of the crystallization process, especially the conformational change of polymer chains and their packing into the crystal lattice, which are described as the simultaneous process in Hoffman theory,1 is not sufficiently investigated. When polymer is crystallized from solution, separation of the chain conformation transformation and chain packing is possible.2,3 On the basis of the study on crystallization induced gelation of /-PS in transdecalin,4 Keller suggests that the conformational change before chain packing is aided by the stabilizing association with solvent molecules. Recently, we are investigating the solution crystallization of high molecular weight poly (ethylene oxide) (PEO) in ethanol at the concentrations close to the overlap limit. The preliminary results imply that at a temperature slightly higher than the dissolution temperature (T_s) of PEO crystals, the PEO chain conformation looks more ordered than that at higher temperatures and can thus promote the crystallization process significantly.
Yun-Shu Zhang Er-Qiang Chen
Beijing National Laboratory for Molecular Sciences, Department of Polymer Science and Engineering and the Key Laboratory of Polymer Chemistry and Physics of the Ministry of Education, College of Chemistry, Peking University, Beijing, 100871, China
国际会议
PP’2010，Jinan International Symposium on Polymer Physics(2010济南国际高分子物理学术研讨会)
济南
英文
321-322
2010-06-06（万方平台首次上网日期，不代表论文的发表时间）