Aromatic copolyesters based on diphenylol-propane and 3,5-dibromo-p-hydroxybenzoic acid (p-HBA) were synthesized by an acceptor-catalyzed polycondensation method. During the synthesis, equimolar mixtures of chloranhydrides of isophthalic and terephathalic acids were used. The effects of p-HBA on the tensile and thermal properties of the polyesters were investigated. The breaking stress and modulus of elasticity increased with the amount of p-HBA up to 10% in molar mass. A further increase in p-HBA caused deterioration of the tensile properties. The elongation at break decreased at low p-HBA contents (<5%). The addition of p-HBA increased the molecular packing and the limiting oxygen index and improved the thermal behavior of the synthesized polyesters. (C) 2008 Wiley Periodicals, Inc. J Appl Polym Sci 111: 1755-1762, 2009