Telechelic oligoisoprenes were successfully prepared by the selective controlled degradation of natural rubber, a renewable source, via epoxidation and cleavage reactions. The molar mass of the oligoisoprene product obtained depends on the degree of epoxidation of the starting materials. The chemically modified structures obtained via epoxidation, hydrogenation, and ring opening of epoxide groups were also studied, and the chemical structures and thermal properties of the oligoisoprene products were determined. Moreover, the preliminary study of preparation of hydroxytelechelic natural rubber (HTNR)-based polyurethane foam was performed. A novel HTNR-based polyurethane foam was successfully prepared and its thermal properties were investigated and the results indicated that the HTNR-based polyurethane foam has a good low temperature flexibility. (C) 2010 Wiley Periodicals, Inc. J Appl Polym Sci 117: 1279-1289, 2010