Improved Manufacturing of High-Performance Composites by Frontal Polymerization

Abstract

Current manufacturing methods for high-performance fiber-reinforced polymer composites (FRPCs) are time and energy intensive, and their cost and complexity often act as a deterrent to wider the adoption of these materials. Frontal polymerization (FP) has recently been demonstrated as an energy-efficient, out-of-autoclave technique for the manufacture of thermosetting FRPCs. In this process, polymerization is achieved through a self-propagating exothermic reaction wave, triggered by an external thermal stimulus, that converts the liquid monomer to a fully cured polymer. Here, we demonstrate rapid manufacture of woven carbon fiber-reinforced composites with fiber volume fractions, up to up to 66%, a 30% increase over prior FP-based processing methods, using a combination of hot-pressing techniques, vacuum-assisted resin transfer molding, and FP. Higher values of the polymerization rate, maximum front temperature, degree of cure, glass transition temperature, and fiber volume fraction of these FRPCs are achieved by using different catalyst loadings and thermal triggering mechanisms. A systematic study reveals the effect of varying the catalyst loading on the mechanical and thermomechanical properties of the resulting FRPCs.