Production of polymeric composites based upon photopolymerization methods

A novel method for the rapid and inexpensive production of polymeric composites based upon photopolymerizations is reported. We have used photopolymerizations to produce polymeric, glass-fiber composite structures, with thicknesses exceeding 1 centimeter, from several commercially available vinyl ester resins. The photopolymerization reactions are relatively rapid and result in the formation of composites with good mechanical properties. We have investigated the effects of processing parameters on the properties of these photocured composites. These studies include the effects of variables such as light intensity, initiator concentration, exposure time, and fiber loading on the mechanical strength of the photocured composite materials. In addition, modified photo-differential scanning calorimetry (DSC) and adiabatic temperature rise studies were used to characterize the kinetics of these reactions. Thermal and mechanical properties of the composites were characterized by thermogravimetric analysis and measurements of flexural modulus. Composites produced by photoinitiated polymerizations yielded properties comparable to composites that had been thermally cured for 24 hours.