Polyesters have been synthesized by polycondensation of terephthaloyl dichloride or isophthaloyl dichloride with hindered biphenols and hydroquinones which contain bulky substituents (methyl and phenyl) on the arylene ring. Polymers derived from isophthaloyl dichloride have better solubility and lower glass transition temperatures than the corresponding polymers obtained from terephthaloyl dichloride.