Rheo-Optical Study on Dynamics of Bottlebrush-Like Polymacromonomer Consisting of Polystyrene.
Rheo-Optical Study on Dynamics of Bottlebrush-Like Polymacromonomer Consisting of Polystyrene.
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DOI：
10.1021/ma2008332
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发表时间：
2011-06
期刊：
影响因子：
5.5
通讯作者：
Hiroshi Iwawaki;Tadashi Inoue;Yo Nakamura
中科院分区：
文献类型：
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作者：
Hiroshi Iwawaki;Tadashi Inoue;Yo Nakamura
在从玻璃到橡胶过渡区到流动区的宽频率范围内进行了瓶刷状聚苯乙烯大分子单体的动态双折射和粘弹性测量，以讨论高度支化结构对聚合物链动力学的影响。与线性聚苯乙烯类似，高频下应变诱导双折射为负值，而在流动区为正值，表明主链段具有正光学各向异性。通过使用改进的应力光学规则（MSOR），复数模量被分解为两个分量，主链分量和支链分量。发现主链的动态刚度（每个粘弹性链段的重复单元数）大约是线性聚苯乙烯的 10 倍。强烈建议侧链的协同运动源自分支之间的排斥相互作用。
Dynamic birefringence and viscoelastic measurements of bottlebrush-like polystyrene polymacromonomer were conducted over a wide frequency region covering from the glass-to-rubber transition zone to the flow zone in order to discuss effects of highly branched structure on polymer chain dynamics. Strain-induced birefringence at high frequencies was negative, similarly to linear polystyrenes, while it was positive in the flow zone, indicating the main chain segment has positive optical anisotropy. By using the modified stress-optical rule (MSOR), the complex modulus was decomposed into two components, main chain and branch components. The dynamical stiffness of main chain (number of repeating units per viscoelastic segment) was found to be approximately 10 times larger than that for linear polystyrenes. The cooperative motion of the side chains originated by the repulsive interaction between the branches was strongly suggested.