Affiliation: | aArmy Research Laboratory, AMSRD-ARL-WM-MC, Aberdeen Proving Grounds, MD 21005-5069, United States bCenter for Composite Materials, University of Delaware, Newark, DE 19716, United States cDepartment of Chemical and Biological Engineering, Drexel University, Philadelphia, PA 19104, United States |
Abstract: | Vinyl ester (VE) resins with a bimodal distribution of molecular weights were prepared via methacrylation of epoxy monomers. Bimodal VE resins and neat polymers had viscosities and mechanical properties similar to that of commercial resins. E-glass composites were prepared and also found to have similar mechanical and thermo-mechanical properties relative to composites fabricated using commercial resins. However, the fracture toughness of the bimodal resins was superior to that of the commercial resins partially as a result of increased molecular relaxations that were manifested in a broader glass transition. Overall, bimodal resins allow for the use of low styrene content (33 wt%), while maintaining excellent thermal, mechanical, and fracture properties for the neat resins and composites. |