作　　者： (张恩菘）; (代学民）; (刘学）; (杨文轲）; (刘巍）; (董志鑫）; (邱雪鹏）; (姬相玲）;

机构地区： 中国科学院长春应用化学研究所高分子物理与化学国家重点实验室 中国科学院大学,北京100049

出　　处： 《高分子学报》 2017年第9期1497-1505,共9页

摘　　要： 合成了一种聚酰胺酸6FDA-TFDB溶液,利用流变仪研究其在不同影响因素(如:温度、升温速率、溶剂含水量等)下的流变行为,发现聚酰胺酸溶液的降解在高温区和低温区存在不同的行为.通过Andrade公式获得不同条件下聚酰胺酸溶液的黏流活化能,并比较其差异,同时对溶剂水含量在不同温度区域下对聚酰胺酸降解速率的影响也进行了深入的分析,从而建立一种半定量比较不同条件下聚酰胺酸溶液降解速率的方法. As a precursor of polyimide, poly（amic acid） （PAA） has significant influence on the properties of thefinal materials. The stability of PAA solution under different conditions is also important to control the propertiesof PI. In this work, soluble 6FDA-TFDB PAA was synthesized and its solution was obtained. Using FTIR,IH-NMR and GPC techniques, the molecular information of PAA was obtained. The degradation behavior wasinvestigated by rheometer under different conditions （temperature, heating rate, water content, etc.）. It was foundthat the degradation rate in a high temperature region was much faster than that in a low temperature region, and acritical temperature was found to exist between these two temperature regions. Influence of added water amountin PAA solution on degradation behavior was also considered. In order to analyze precisely the influence of wateramount on PAA degradation behavior, the amount of water in DMAc was analyzed by Karl Fischer method anddemonstrated that it was too small to influence the relevant results. It was found that water accelerated thedegradation rate of PAA solution in the low temperature region, but was irrelevant in the high temperature region.Based on Andrade equation, the viscous-flow activation energy was obtained and compared to evaluate thedegradation rate of PAA in solution under different conditions, through a semi-quantitative way. Different resultswere found at low/high storage temperatures at low storage temperature the viscosity of PAA solution was keptconstant at first, then increased to a maximum and finally decreased; at high storage temperature it decreasedgradually to a low value and remained constant. Based on degradation mechanism of PAA chains, the degradationbehavior under different conditions was explained. This work provides a guide to tune the solution properties ofPAA, and also to control the properties ofpolyimide materials.

关 键 词： 聚酰胺酸 降解行为 流变仪 黏度 黏流活化能