含硫醚结构联苯型聚酰亚胺的合成及结构性能表征

Synthesis and Characterization of Biphenyl Polyimide Containing Alkyl Sulfide Structure

以4,4’-二氨基二苯硫醚(SDA)和联苯四酸酐(BPDA)为原料,通过溶液缩聚-热酰亚胺化/化学酰亚胺化的方法制备了一种新型的含硫醚结构联苯型聚酰亚胺。利用高级旋转流变仪在线跟踪反应进程,采用热失重分析仪研究反应条件对热酰亚胺化及化学酰亚胺化法的影响,为进一步制备高性能的聚酰亚胺建立有效的实验手段和方法。采用小角激光光散射法、红外光谱、元素分析、接触角仪、DSC等方法对聚合物的结构与性能进行表征。结果显示,硫醚结构的引入使聚合物的表面张力与铜箔相当,可有效改善聚合物薄膜的表面性能,其与铜箔之间的黏附功明显大于传统聚酰亚胺,在无胶挠性线路板应用方面显示出较好的应用前景。所获聚合物的绝对重均相对分子质量为(3.8±1.1)×104g/mol,分解温度均高于560℃;DSC的结果显示所制备的两种酰亚胺化聚合物均具有较高的玻璃化转变温度,相比之下,化学酰亚胺化更有利于获得高酰亚胺化程度的聚合物,产物的玻璃化转变温度也更高。

A novel polyimide containing alkyl sulphide structure was synthesized through polymerization of 4,4＇-diamino diphenyl sulphide（SDA） and 3,3′,4,4′-biphenyl-tetracarboxylic acid dianhydride（BPDA） by thermal imidization and chemical imidization.A real-time online tracing method was built up by using the advanced rheology expanded systems（ARES）,as well as the effects of reaction conditions to the thermal and chemical imidization by thermogravimetic analysis,which provided more efficient methods for preparing high performance polyimide.The structures and properties of the polyimide were characterized by fourier transform infrared spectroscopy（FTIR）,small angle laser light scattering（SALS）,contact angle analysis and differential scanning calorimetry（DSC） etc.The results showed that the surface properties of polyimide films were great improved by introducing the alkyl sulphide structure into the main chain of polyimide,which exhibited similar surface tension with copper foil,and higher adhesion work between the new polyimide and copper foil than the traditional one.The absolute weight-average molecular weight of the polyimide was determined to be（3.8±1.1）×104 g/mol;the decomposition temperature was higher than 560 ℃.The DSC results showed that the polyimides by both thermal and chemical imidization were with high glass transition temperature.In comparison,chemical imidization was beneficial to getting high degree of imidization,resulting in higher glass transition temperature.