We synthesized water-insoluble polymers, poly(beta-cyclodextrin-co-citric acid)s, by heating a mixture of citric acid, cyclodextrin (CD), and Na2HPO4 as a catalyst with a 6 : 1 : 2 molar ratio at 160, 170, and 180 degrees C for 10 and 20 min. The chemical composition of the polyesters was determined by high pressure liquid chromatography (HPLC) analysis of the polymer hydrolysates. The cross-linking mechanisms and thermal degradation of the polymers were also investigated. The polyesters contained 30-35% citric acid, 1-4% unsaturated carboxylic acids (i.e., itaconic, cis-aconitic, trans-aconitic, and mesaconic acids), and 60-70% CD, whereas about 40% of them were able to form inclusion complexes. (C) 2010 Wiley Periodicals, Inc. J Appl Polym Sci 119: 3511-3520, 2011