Mashita Ryo, Saito Makina, Yoda Yoshitaka, Kishimoto Hiroyuki, Seto Makoto, Kanaya Toshiji
Chemical Analysis Center, Sumitomo Rubber Industries Ltd, Tsutsui-cho, Chuo-ku, Kobe, Hyogo 651-0071, Japan.
Department of Physics, Graduate School of Science, Tohoku University, Sendai, Miyagi 980-8578, Japan.
J Synchrotron Radiat. 2022 Sep 1;29(Pt 5):1180-1186. doi: 10.1107/S1600577522007998. Epub 2022 Aug 23.
A synchrotron-radiation-based quasi-elastic γ-ray scattering system has been developed that uses time-domain interferometry to observe microscopic polymer dynamics under uniaxial deformation. The stress-producing mechanism of crosslinked polybutadiene has been studied from a microscopic viewpoint. It was found that the mean relaxation time ⟨τ⟩ of the microscopic polymer motion observed over a relatively high temperature (T) range (i.e. T < 0.0045 K) increased with elongation on both the intra- and intermolecular scales. Following an extensive strain dependence study, it was found that the strain dependences of both the intra- and intermolecular ⟨τ⟩ changed with the stress dependence. It was therefore suggested that ⟨τ⟩ increased due to the constraint of the local polymer chain motion caused by elongation. The local molecular dynamics of polymer chains under uniaxial deformation could be evaluated at intra- and intermolecular scales separately for the first time using our method.
已开发出一种基于同步辐射的准弹性γ射线散射系统，该系统利用时域干涉测量法观察单轴变形下的微观聚合物动力学。从微观角度研究了交联聚丁二烯的应力产生机制。研究发现，在相对较高温度（T）范围（即T < 0.0045 K）内观察到的微观聚合物运动的平均弛豫时间⟨τ⟩在分子内和分子间尺度上均随伸长而增加。经过广泛的应变依赖性研究，发现分子内和分子间⟨τ⟩的应变依赖性均随应力依赖性而变化。因此，有人认为⟨τ⟩的增加是由于伸长导致局部聚合物链运动受到限制。使用我们的方法首次能够在分子内和分子间尺度上分别评估单轴变形下聚合物链的局部分子动力学。
