Synthesis and polymerization of plant oil monoglyceride maleates

Abstract

In this study, rigid thermoset polymers were synthesized from radical copolymerization of the soybean oil monoglyceride maleates with styrene. In the first part of the study, soybean oil monoglycerides (SOMG) were obtained from the reaction of soybean oil with glycerol at 220-2400C. An optimization of the glycerolysis reaction was achived through the use of a large amount of excess glycerol and with a rapid cooling process at the end of the reaction to maximize the monoglycride yield. In the following step, soybean oil monoglycerides (SOMG) were reacted with maleic anhydride at temperatures around 1000C to produce the SOMG maleate half esters. Different catalysts and different reaction conditions were examined to increase the maleate half ester's yields. The reactions were followed by IR and 1H-NMR and the products were charecterized by mass spectrometry. In the final step, the radical initiated copolymerization of the SOMG maleates with styrene produced rigid, thermoset polymers. The SOMG maleates were found to be effective emulsifying agents, thus the emulsion copolymerization of the SOMG maleates with styrene was also carried out successfully without the addition of an emulsifier. The obtained polymers were characterized by IR and 1H-NMR, the cross linked net work structure of the coploymers was examined with the swelling behaviour in different solvents. The resulting copolymers of SOMG maleates with styrene are suitable for fiber reinforcement and can be used as a liquid molding resin with the right fiber reinforcement.