Synthesis, characterization and fibre (glass and carbon) reinforced composites of poly(amido-imide)s

An amino-terminated oligoimide was prepared by the Michael addition reactio n of 4,4'-diamino diphenyl ether bismaleimide (DDEBM) and 4,4'-diamino diph enyl methane (DDM) at a DDEBM:DDM molar ratio of 1:2. The poly(amido-imide) s (PAI)s were also prepared by condensation of this DDEBM:DDM oligoimide wi th various aliphatic bisesters. The resultant PAIs were characterized by el emental analysis, IR spectral studies and number average molecular weight ( (M) over bar(n)) estimated by non-aqueous conductometric titration. The cur ing behaviour of the diglycidyl ether of bisphenol-A (a commercial epoxy re sin) (DGEBA)-PAI system was monitored by differential scanning calorimetry (DSC). Unreinforced PAI-epoxy cured products have also been prepared and an alysed thermogravimetrically. Glass and carbon fibre reinforced laminates ( i.e. composites) of the PAI-epoxy resin system have been prepared and duly characterized. Their mechanical properties have been compared with commerci al composites.