Poly(amide-imide)s containing polybutadiene blocks

Poly(amide-imide)s containing polybutadiene blocks were prepared by reactio n of 4,4'-methylenedi(phenyl isocyanate) with trimellitic anhydride and alp ha,omega-diisocyanatopoly-butadiene. The polymers were characterized by spe ctroscopic methods and X-ray diffraction. Incorporation of 5 wt.% of polybu tadiene structures into polyimide decreases the temperature of 10% weight l oss in nitrogen by 90 degrees C. Glass transition temperature of the polyme r also decreases with the increasing content of soft polybutadiene segments , but the decrease is moderate for the contents higher than 20 wt.%. Broad amorphous halo dominates wide-angle X-ray diffractograms of all the samples , but sharper peaks of a more ordered structure were observed in definite c oncentration range of polybutadiene blocks. The copolymers are soluble in N -methylpyrrolidone.