The Synergistic Effect of Lamellar Cobalt Phosphate and Sodium Metaborate Hydrate Improves the Flame Retardancy of Epoxy Resin

The aim of this paper is to probe the synergistic effect of cobalt phosphate (Co-Pi) and sodium metaborate hydrate (SMB) on the flame retardancy of aqueous epoxy resins. In situ growth of sodium metaborate on cobalt phosphate surfaces by co-precipitation to form a multi-functional flame retardant material and the prepared mixture was added to a waterborne epoxy resin to improve the inflaming retarding of the resin. Finally, water-based epoxy resin with flame retardant was applied to the wood for performance testing. After experimental comparison, the Co-Pi@SMB3%/EP shows the best results in maximum decomposition temperature (374.3 degrees C), the residual carbon (26.6 %), the limiting oxygen index (26 %), time to ignition (26 s) peak heat release rate (173.9 kW/m(2)), total heat release (41.35 MJ/m(2)), peak smoke release rate (0.060 m(2)/s), total smoke release (5.6 m(2)), peak CO release (0.035 g/g), and peak CO2 release (0.613 g/g), possessing the optimum flame retardant effect. The residual char after the limiting oxygen index test was characterized, and it was confirmed that the Co-Pi@SMB composites have good flame retardant feature.