ABSTRACT:A new diimide-diacid chloride (3) containing a noncoplanar 2,2Ј-dimethyl-4,4Ј-biphenylene unit was synthesized by treating 2,2Ј-dimethyl-4,4Ј-diamino-biphenylene with trimellitic anhydride followed by refluxing with thionyl chloride. Various new poly(ester-imide)s were prepared from 3 with different bisphenols by solution polycondensation in nitrobenzene using pyridine as hydrogen chloride quencher at 170°C. Inherent viscosities of the poly(esterimide)s were found to range between 0.31 and 0.35 dL g Ϫ1 . All of the poly(ester-imide)s, except the one containing pendent adamantyl group 5e, exhibited excellent solubility in the following solvents: N, N-dimethylformamide, tetrahydrofuran, tetrachloroethane, dimethyl sulfoxide, N,N-dimethylacetamide, N-methyl-2-pyrrolidinone, m-cresol, o-chlorophenol, and chloroform. The polymers showed glass-transition temperatures between 166 and 226°C. The 10% weight loss temperatures of the poly(ester-imide)s, measured by TGA, were found to be in the range between 415 and 456°C in nitrogen.