In this study, rigid thermoset polymers were prepared from radical copolymerization of linseed oil monoglyceride maleates with styrene (St). First, linseed oil monoglycerides (LOMGs) were obtained from the reaction of linseed oil with glycerol at 220-240 degrees C. Then, LOMGs were reacted with maleic anhydride at 80 degrees C to produce the LOMG maleate half esters. The reactions were followed by FTIR spectroscopy and size exclusion chromatography (SEC) and the final resin was characterized by H-1-NMR spectroscopy. Finally, radical copolymerization of the LOMG maleates with 20,40,60, and 80 % by weight of St was performed to produce rigid, thermoset polymers. The thermomechanical properties and fracture behavior of the cured copolymers, as a function of the percentage of St, were measured and analyzed. The copolymer with 40 % by vveight of St was the material with better mechanical and fracture behavior. (c) 2005 Wiley Periodicals, Inc.