Novel Bismaleimide - Epoxy Resin System: III

Novel diamines, namely N,N′-bis[1-(4-aminophenyl) ethanonyl]-4,4′-(1,1′-biphenyl)diamine (DA1), N,N′-bis[1-(4-aminophenyl) ethanonyl]-4,4′-(1,1′-biphenyl methane) diamine (DA2) and N,N;-bis[1-(4-aminophenyl) ethanonyl]-4,4′-(oxybisphenyl)diamine (DA3) have been prepared and reacted with various bismaleimides (BM) at a BM: diamine ratio of 1:2. The resulting oligoimides have been characterized by elemental analysis, IR spectral studies, and thermogravimetry. Their number average molecular weights ( M ¯ n) were estimated by nonaqueous conductometric titration. All of the oligoimides have been used as curing agents for epoxy resins based on the diglycidyl ether of bisphenol-A, and studied by differential scanning calorimetry (DSC). Glass and carbon fibre reinforced composites have also been prepared and characterized by mechanical properties.