【摘要】 由于聚酰亚胺分子链的刚性，在成膜过程中，其分子链沿膜平面排列（取向），构成了各向异性，导致膜平面方向与垂直于膜平面方向的物性参数（如折射率、介电系数）不相同。文中总结了各种研究聚酰亚胺膜各向异性的方法，证明聚酰亚胺膜具有各向异性。更多还原

【Abstract】 Due to the rigidly of the main chains of polyimides, the chain orientation in the film plane take place, which was often known as inplane orientation. As a result, anisotropy was formed. There is divergence in physical properties such as refractive indices and permittivity along inplane and outofplane directions. The means of characterizing anisotropy of undrawn polyimide films were reviewed in this paper to confirm the fact that polyimide films were characteristics of anisotropy.更多还原