The different natural oils epoxidized with 3-chloroperbenzoic acid were crosslinked with diepoxy reactive diluents, bisphenol A propoxylate diglycidyl ether, and 3,4-epoxycyclohexylmethyl-3,4-epoxyclohexane-carboxylate, using cationic initiator at 60 degrees C and photoinitiators at the room temperature. The insoluble fraction of the polymeric products was 59-90%. The Young modulus of the crosslinked polymer films ranged from 2 to 861 MPa. The 10% weight loss temperatures of the crosslinked polymers estimated by thermogravimetric analysis were in the range from 250 to 420 degrees C. The water vapor transmission rate of the crosslinked biopolymer films ranged from 6 to 49 g/m(2)/24 h. Biochemical oxygen demand and biodegradation in soil of the crosslinked polymers were studied. The crosslinked polymers showed higher biodegradation rate than cellulose, starch, and polyvinylalcohol. (C) 2009 Wiley Periodicals, Inc. J Appl Polym Sci 115: 2028-2038, 2010