Characterization of Polymer Thin Films with ISTS

对聚酰胺薄膜进行了力学性能测试，包括杨氏模量、倾倒速率、结构松弛和热扩散等。柔性聚合物的倾销率不是很高，因为它受高分子链的局部运动的影响。杨氏模量对薄膜厚度很敏感。这解释了在厚度小于1微米的薄膜中诱导了自发的分子取向。非破坏性、实时空间选择性的ISTS测量尤其有效地发现了薄膜的这种性质，光敏聚酰胺的ISIS信号甚至在光交联的早期阶段就发生了变化，表明ISS反映了聚合物基质微环境的微小变化

ISTS measurement of polymide thin films were performed to obtain their mechanical properties such as Young's modulus, dumping rate, structural relaxation and thermal diffusion. The dumping rate of flexible polymer is not too high because it is affected by the local motion of polymer chainsYoung's modulus was found to be sensitive to the film thickness. That is explained that the spontaneous molecular orientation is induced in the film with thickness less than one micror. Such properties of thin films is especially effectively found with ISTS measurement that is non destructive, real time spatially selective method,The ISTS signal of a photosensitive polymide changed even in the early stage of photocrosslinking, showing that the ISTS reflects small change of micro-environment of the polymer matrix