LIGHT-SCATTERING-STUDIES OF SHORT-RANGE AND LONG-RANGE DENSITY AND ANISOTROPY FLUCTUATIONS IN A BULK POLYSILOXANE
LIGHT-SCATTERING-STUDIES OF SHORT-RANGE AND LONG-RANGE DENSITY AND ANISOTROPY FLUCTUATIONS IN A BULK POLYSILOXANE
复制标题
块状聚硅氧烷的短程和长程密度以及各向异性波动的光散射研究
DOI：
10.1021/ma00127a033
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发表时间：
1995
期刊：
影响因子：
5.5
通讯作者：
K. Kaji
中科院分区：
文献类型：
--
作者：
T. Kanaya;A. Patkowski;E. W. Fischer;J. Seils;H. Gläser;K. Kaji
通过光散射研究了长程密度波动对聚（甲基对甲苯基硅氧烷）（PMpTS）中初级（α-）弛豫的影响。结果表明，长程密度涨落（簇）仅对极化（VV）相关函数有贡献，而对去极化（VH）相关函数没有贡献，并使系统在α过程的时间尺度上明显非遍历。在温度跳跃实验中，通过在55℃下退火不同时间间隔获得具有不同簇数量的样品：+120→+55→-2.6℃。从 VH 相关函数（有簇样本）和 VV 和 VH 相关函数（无簇样本）获得的平均弛豫时间及其 α 过程的分布是相等的，并且不依赖于簇的数量，表明长程密度涨落与初级 α 弛豫之间没有耦合。
The effect of long-range density fluctuations on the primary (α-) relaxation in poly(methyl-p-tolylsiloxane) (PMpTS) was studied by means of light scattering. It is shown that the long-range density fluctuations (clusters) contribute only to the polarized (VV) and not to the depolarized (VH) correlation functions and make the system apparently nonergodic in the time scale of the α-process. Samples with different amounts of clusters were obtained by annealing at 55 °C for different time intervals in temperature jump experiments : +120 → +55 → -2.6 °C. The mean relaxation times and their distribution of the α-process obtained from the VH correlation functions (sample with clusters) and both VV and VH correlation functions (cluster-free sample) were equal and did not depend on the amount of clusters, indicating no coupling between the long-range density fluctuations and the primary α-relaxation.