Functionalized graphene with Platelet-like magnesium hydroxide for enhancing fire safety, smoke suppression and toxicity reduction of Epoxy resin

Abstract

With the rapid development of Graphene based hybrid materials, various of them were fabricated to improve the fire safety of EP. However, the effect of GO content in the hybrid material on flame retardancy of EP composites is rarely reported. In order to find the optimal ratio of GO/Mg(OH)2, platelet-like Mg(OH)2 functioned graphene (GPM) were synthesized with diverse content GO substance and then presented into EP resin for improving its fire retardancy. Various characterizations confirmed its composition, structure and morphology. The incorporation of GPM contains about 1% GO increased the tensile strength by 31.6% compared to that of untreated Mg(OH)2. The GPM contains about 5% GO exhibited the finest fire safety in various EP composites. The fire-retardant assessments illustrated that the limiting oxygen index (LOI) of EP composite with 3 wt% GPM progressed to 27.8% compared with virgin EP (24.4%). In parallel, compared to virgin EP, the peak heat release rate, peak smoke production rate, total smoke production and peak CO production rate of EP/5GPM were diminished by 50.9%, 44.0 %, 25.5% and 53.1%, separately. The mechanism investigation revealed that the prominent flame retardancy and smoke suppression were attributed to the physical barrier of GO, the endothermic decomposition of Mg(OH)2, the barrier effect of MgO and synergistic effect between GO and Mg(OH)2 toward the optimized carbonization. In perspective, hierarchical platelet structure with synergistic effect offered an effective approach for the fire-safe polymer.