A series of aromatic polyesters containing 1,6-diazaspiro[4,4]-nonane-2,7-dione were synthesized under phase-transfer conditions. The copolymers were obtained in essentially quantitative yield, theses were soluble in common organic solvents, and would readily form clear, colorless films from solution. The optimum conditions of polymerization, was obtained via polycondensation at room temperature and reaction time of 4 h in chloroform. All polymers were characterized by FTIR, GPC, viscosity, water contact angle, water absorption, TGA, DSC and TMA. The prepared polyesters showed excellent thermal stability, as measured by TGA (10 wt% loss), are only moderate due to the alicyclic component and range from 365 to 401 ° C in air; however, glass transition temperatures are quite high (245-309 ° C). The inherent viscosities of these solutions ranged from 0.77 to 1.40 dl g(-1), depending on the polyester structure. The structures of the polyesters were confirmed by FTIR spectroscopy. © 2005 Elsevier Ltd. All rights reserved.