Through-thickness frontal polymerization: Process development and optimization

Current methods for the manufacture of fiber-reinforced polymer composites (FRPCs) are energy intensive, time consuming, and have adverse effects on the environment. Frontal polymerization (FP) is an out-of-autoclave, self-sustaining cure process garnering significant adoption by enabling rapid and energy-efficient manufacture of FRPCs. Prior FP-based manufacture of FRPCs rely on in-plane triggers to initiate the reaction. In the present study, we adopt through-thickness curing of carbon FRPCs with emphasis on the energy input required and the resulting composite properties. High energy input resulted in high glass transition temperature (T_g=156 °C), fiber volume fraction (V_f=65%), and low void content (V_v≈0). Computational modeling and optimization complement the experiments with focus on further reducing the energy whilst maintaining the favorable properties achieved at high energy inputs. A 27.5% reduction in energy resulted while maintaining similar performance.