Photopolymerizations of vinyl ester: Glass fiber composites

The spatial and temporal control afforded by photopolymerizations make them attractive for rapid and inexpensive Processing of polymeric composites. We have investigated the production of thick polymers and glass fiber composites using commercially available vinyl ester resins. The studies illustrate the effects of light intensity, initiator formulation and concentration, exposure time, and fiber loading on the mechanical properties of the photocured composite materials. With moderate incident light intensities and high fiber loadings the photopolymerizations were found to proceed to completion in minutes to yield composites good mechanical properties. A hybrid photo/thermal initiation strategy in which heat released from an exothermic photopolymerization leads to the additional dissociation of a thermal initiator was found to be especially promising for the production of thick polymers and composites.