 The diester product is then dissolved in a reactive solvent, such as styrene, to approximately 35–45 percent content by weight.Polymerization is initiated by free radicals, which are generated by UV-irradiation or peroxides.This thermoset material can be used as an alternative to polyester and epoxy materials as the thermoset polymer matrix in composite materials, where its characteristics, strengths, and bulk cost are intermediate between polyester and epoxy.