Preparation and properties of silane-endcapped polyimide adhesives

Silane-endcapped polyimide high temperature adhesive formulations were prepared by reacting anhydride-terminated poly(amic acid), obtained from benzophenonetetracarboxylic dianhydride and a diamine (3,3'-, 3,4'- or 4,4'-diaminodiphenylmethane and 3,3', 3,4'- or 4,4'-diaminobenzophenone) with varying amounts of gama-aminopropyltriethoxysilane in dimethylacetamide. Resin properties were evaluated by torsional braid analysis and thermogravimetric analysis. Lap shear strengths of some of the adhesive bonds were determined at room temperature and at 177 C before and after ageing at 200 C for 2500 h and after boiling in water for 72 h.