Rheological Behaviors of a Series of Hyperbranched Polyethers
Rheological Behaviors of a Series of Hyperbranched Polyethers作者机构:Key Laboratory of Carbon Fiber and Functional Polymers Ministry of Education Beijing University of Chemical Technology TA Instruments-Waters LLC (Beijing) 9/F Tongniu International Manson State Key Laboratory of Organic-Inorganic Composites Beijing University of Chemical Technology
出 版 物:《Chinese Journal of Polymer Science》 (高分子科学(英文版))
年 卷 期:2015年第33卷第11期
页 面:1574-1585页
核心收录:
学科分类:08[工学] 0805[工学-材料科学与工程(可授工学、理学学位)] 080502[工学-材料学]
基 金:financially supported by the National Natural Science Foundation of China(No.51173012) "The Fundamental Research Funds for the Central Universities"at Beijing University of Chemical Technology
主 题:Hyperbranched polyethers Rheology Time temperature superposition
摘 要:Hyperbranched polyethers with different structures and molecular weights(MW) were synthesized using the A2+B3 approach by varying monomer ratio, A2 structure, and reaction time. Effects of backbone structure and MW on melt rheological behaviors were investigated by both small amplitude oscillatory shear and steady shear measurements. Master curves were constructed using the time-temperature superposition principle and compared. In the reduced frequency range covered, lg G″-lg(ω·aT) always show a slope of 1.0, suggesting a terminal zone behavior; in contrast, unexpected step changes or plateaus are observed on lg G′ master curves. Effects of backbone structure and MW on master curves were discussed. The Cox-Merz rule was tested at different temperatures and was found to be applicable when flow instability was absent.