抗高温蠕变高粘结性共聚酰亚胺应变胶研究

Studies on the Copolyimide Strain Adhesive Creep-Resistance and High Adhesion at High Temperature

采用两苯酐间连接不同桥基的几种二元酐 ,与二元胺经溶液共聚合成共聚酰胺酸 ,两种不同结构的共聚酰胺酸共混再配加适量酚醛树脂 ,制成棕黄色透明粘稠应变胶。用其胶膜在不同温度下进行热亚胺 (固 )化反应 ,测试了形成的半互穿聚合物网络的粘接、蠕变等性能 ,其中粘结力和抗蠕变性突出。制成的箔式电阻应变计 ,经老化和蠕变测试达到并超过国家标准的高等级指标。

To improve adhesion and creep-resistance behaviour of polyimide (PI), the copolyamic acids (CPA) were prepated, and the blends of OB′B、MPB′B and PF for strain adhesives were selected. The effects of component structure and imidization (cure) temperature (T i) on the properties of copolyimide (CPI) and its SIPN formed at imidization (cure) process were studied, and the creep bdhaviour of polymers at 280 ℃ has been investigated. The results show that polymer Ⅷ is a SIPN with optimum comprehensive properties, it is suitably used for making strain gages with good creep-resistance at 250 ℃.