The controlled reaction of equimolar quantities of maleic anhydride and glycidol in dimethoxyethane gives soluble polyesters with one hydroxyl group in each repeating unit. The reaction proceeds with stepwise ring opening of the components and gives highly viscous clear solutions in relatively short periods. In the first step, monomaleate ester formation takes place around 80 degreesC. The ring opening of the oxirane group is the second step, and it occurs at 120 degreesC. The overall reaction is the formation of soluble polyesters with moderate molecular weights (6000-18,000), without the elimination of water. The soluble polyesters can be crosslinked tightly by direct heating at 190 degreesC without additional vinyl monomer. (C) 2003 Wiley Periodicals, Inc.