Linear Viscoelasticity and Birefringence of Poly-γ-Benzyl-L-Glutamate Solutions
Linear Viscoelasticity and Birefringence of Poly-γ-Benzyl-L-Glutamate Solutions
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聚-γ-苄基-L-谷氨酸溶液的线性粘弹性和双折射率
DOI：
10.1021/acs.macromol.1c01398
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发表时间：
2021
期刊：
影响因子：
5.5
通讯作者：
Urakawa Osamu
中科院分区：
文献类型：
--
作者：
Inoue Tadashi;Furusawa Naomi;Urakawa Osamu
本文测量了两种聚谷氨酸苄酯在间甲酚溶液中从稀到紧缠结的较宽浓度范围内的复模量和应变光学系数。在稀区得到的实验数据进行了比较与理论由莫尔斯和同事的稀溶液，它预测三个松弛模式，张力，曲率和取向。我们发现，该理论很好地描述了稀溶液的复数模量。随着浓度的增加，由于流体动力学相互作用，这三种弛豫模式都发生了延迟。此外，拓扑相互作用也延缓了取向模式。利用应变光学系数和分子理论将紧纠缠区的复模量分解为分量模量。曲率应力有助于橡胶平台模量在紧密纠缠区域，如莫尔斯理论的纠缠系统的预测。然而，曲率应力的松弛时间比基于固定管模型的理论预测短。我们推测，约束释放加速了曲率应力的松弛，但对取向应力的影响不大。
The complex modulus and the strain-optical coefficient for two samples of poly-γ-benzyl-l-glutamate inm-cresol solution were measured over a wide concentration regime covering from a dilute to tightly entangled region. The obtained experimental data in the dilute region were compared with the theory by Morse and coworkers for dilute solutions, which predicts three relaxation modes, tension, curvature, and orientation. We found that the theory well described the complex modulus of dilute solutions. With increasing the concentration, the three relaxation modes retarded, due to the hydrodynamic interaction. In addition, the topological interaction also retarded the orientation mode. The complex modulus of the tightly entangled region was separated into the component moduli using the strain-optical coefficient and the molecular theory. The curvature stress contributed to the rubbery plateau modulus in the tightly entangled region, as predicted by the Morse theory for the entangled systems. However, the relaxation time of curvature stress was shorter than the theoretical prediction, which is based on the fixed tube model. We speculate that the constraint release accelerates the relaxation of curvature stress but has a little effect on orientational stress.