Self-catalysed frontal polymerisation of structural composites through a gelated resin layer: Proof of concept and energy demand

Frontal polymerisation (FP) has been demonstrated as a promising method for fast and energy-efficient composite manufacturing but suffers from limitations in fibre content (V f ), unless additional heaters, or a resin rich channel, are used to sustain the front. In this work, we propose a novel process configuration using a gelated sacrificial FP resin layer, used as a consumable. Gelation of FP resins is achieved by the addition of 10–15 w% acrylate followed by a short UV-cure cycle. Variation of the acrylate fraction and initiator content allows for control over the front behaviour whilst providing the rigidity to withstand compaction by the high V f fabric stack. Gelated layers are integrated as a consumable in Liquid Composite Moulding processes to produce composites with up to 58% V f , with high glass transition temperatures and maintained mechanical properties. A preliminary environmental impact assessment is carried out to evaluate the potential benefits of the reduced energy consumption of FP as compared to an oven-cure process, mitigated by the environmental impact of the gelated resin layer, showing that in countries with rather clean energy sources, the addition of additional resin layer may offset the benefits of energy reduction.