Construction of bio-based ramie fabric/epoxy resin composites with high flame retardant and mechanical performances

The development of bio-based polymers will be beneficial to reducing carbon emissions. The biobased fiber-reinforced biobased epoxy resin can prepare fully-biobased polymer composites . However, their flame retardation will become a challenging issue. Here, fire-retardant ramie fabrics surface-modified by ammonium polyphosphate (APP) and polyethyleneimine were integrated into an epoxy system followed by fabricating high-performance composites. Notably, the epoxy resin composite with 8.9 % flame retardant displays a UL-94 V-0 rating. Besides, EP/(MF-2) exhibits a remarkably decreased peak of heat release rate (285 kW/m 2 ) in contrast to pristine fabric-reinforced epoxy resin composite (608 kW/m 2 ) from the cone calorimeter test. The improved flame-retardant performance follows the mechanism of the catalytic dehydration and charring effect by phosphorus-containing acids from the degradation of APP. Furthermore, flexural strength of EP/(MF-2) increases by 29 %, compared with neat EP, indicating obvious reinforcement of ramie fabric.