Toughed interface of Mg(OH)₂/polymer composites with improved mechanical performance via intramolecular “bridge”

Most commercialized polymers are flammable, which hinders their practical applications. The commonly employed flame retardant magnesium hydroxide (MDH) additives with high loading concentration will deteriorate the composite mechanical properties. Therefore, achieving flame retardant polymer composites without compromising their mechanical strength becomes imperative. Here, we employed a titanate coupling agent (TC) to modify the MDH surface, successfully achieving a 56.8 % enhancement of mechanical strength and improved flame retardancy in TC-MDH@ethylene-vinyl acetate (EVA) composites, compared to pristine MDH/EVA samples. Moreover, molecular dynamic simulation was performed to unravel that TC could function as intramolecular “bridge” to increase the binding energy via hydrogen bonds, which leads to toughed interface of MDH and polymers, as well as better compatibility and homogeneous dispersion between MDH and EVA. Such strategy could be employed to enhance both mechanical strength and flame retardancy of polymer composites.