Study on the viscoelastic behavior of SEEPS block copolymer based on a modified BSW model  

作　　者：WANG Wanjie ZHENG Qiang YU Qiuming 

机构地区：[1]Department of Polymer Science and Engineering, Zhejiang University, Hangzhou 310027, China [2]State Key Laboratory of Fluid Power Control and Transmission, Zhejiang University, Hangzhou 310027, China

出　　处：《Chinese Science Bulletin》2005年第19期2171-2175,共5页

基　　金：This work was supported by the National Science Foundation for Distinguished Young Scholars (Grant No.50125312) ;the National Natural Science Foundation of China (Grant No.50133020).

摘　　要：Studies on the viscoelastic behavior of styrene- [ethylene-(ethylene-propylene)]-styrene block copolymer (SEEPS) were carried out, and some characteristic viscoelas-tic parameters were calculated. The longest relaxation time τmax was obtained through simulating the relaxation spec-trum on the basis of a modified Baumgaertel-Schausberger- Winter (mBSW) model. The results revealed that there exists a “second plateau” in the low frequency region of the master curves. The reason for this phenomenon is attributed to the entanglement of macromolecular chains. It is suggested that the hard blocks, polystyrene, act as entanglement points, resulting in a topology restraint to the movement of macro-molecular chains. Meanwhile, it is found that the horizontal shift factors (aT) vs temperature in the master curve could be fitted to the Williams-Landel-Ferry (WLF) equation and Ar-rhenius equation respectively and the flow activation energy (Ea) is 127.88 kJ/mol. In addition, the plateau modulus (GN0) and entanglement molecule weight (Me) were calculated.Studies on the viscoelastic behavior of styrene[ethylene-（ethylene-propylene）] -styrene block copolymer （SEEPS） were carried out, and some characteristic viscoelastic parameters were calculated. The longest relaxation time was obtained through simulating the relaxation spectrum on the basis of a modified Baumgaertel-SchausbergerWinter （mBSW） model. The results revealed that there exists a “second plateau” in the low frequency region of the master curves. The reason for this phenomenon is attributed to the entanglement of macromolecular chains. It is suggested that the hard blocks, polystyrene, act as entanglement points, resulting in a topology restraint to the movement of macromolecular chains. Meanwhile, it is found that the horizontal shift factors （aT） vs temperature in the master curve could be fitted to the WiUiams-Landel-Ferry （WLF） equation and Arrhenius equation respectively and the flow activation energy （Ea） is 127.88 kJ/mol. In addition, the plateau modulus （GN） and entanglement molecule weight （Me） were calculated.

关 键 词：苯乙烯共聚物 时间温度重合法则 黏弹性参数 时间光谱 频率曲线 

分 类 号：O631.3[理学—高分子化学]