NEW POLY(AMIDE-IMIDE) SYNTHESES XXII - SYNTHESIS AND PROPERTIES OF POLY(AMIDE-IMIDE)S BASED ON 1,4-BIS(4-TRIMELLITIMIDOPHENOXY)-2-T-BUTYLBENZENE AND AROMATIC DIAMINES

A diimide dicarboxylic acid, 1,4-bis(4-trimellitimidophenoxy)-2-t-buty lbenzene (I), was prepared by the condensation of 1,4-bis(4-aminopheno xy)-2-t-butylbenzene (BAP-tBB) and trimellitic anhydride (TMA) in 1:2 molar ratio. A series of novel poly(amide-imide)s (PAIs) IIIa-1 having inherent viscosities of 0.98-1.51 dL g(-1) were prepared by the triph enyl phosphite activated polycondensation from the diimide-diacid I wi th various aromatic diamines (IIa-1) in a medium consisting of N-methy l-2-pyrrolidone (NMP), pyridine, and calcium chloride. Most of polymer s show excellent solubility in amide-type solvents such as NMP and N,N -dimethylacetamide (DMAc) and formed tough, transparent, and flexible films by casting from DMAc solution. These films had tensile strengths of 71-106 MPa, elongations at break of 5-45%, and initial moduli of 2 .1-2.9 GPa. Most PAIs necked during the tensile testing. The glass tra nsition temperatures of these polymers were in the range 228-286 degre es C and the 10% weight loss temperatures were above 475 degrees C in air or in nitrogen.