Vinyl Ester Networks

摘要

One of the major classes of matrix resins under consideration for applications in infrastructure are vinyl esters. These are comprised of low molecular weight polyhydroxyether with methacrylate endgroups diluted with styrene monomer. The properties of such resins and resultant networks where the molecular weights of the polyhydroxyether oligomer has been varied from 700 to 1000 g/mol and the level of styrene has been systematically changed are under investigation. Both the glass transition temperatures and fracture toughness of the fully cured networks increase as the styrene level is decreased using an oligomer with a number average molecular weight of approximately 700 g/mole. As expected, the volume contraction upon cure also decreases significantly as styrene is decreased, and thus residual cure stresses may be reduced in fiber reinforced composites. Using a 1000 g/mol oligomer, the resistance to crack propagation becomes significantly improved.