Multi-layer core-shell ATH: A novel approach to flame retardant and high-performance EVA composites

Ethylene-vinyl acetate copolymer (EVA) is widely used in various applications; however, its flammability limits the further application in wire and cable industries. Here, a core-shell aluminum hydroxide flame retardant (ATH@ADP@MCA) was prepared by a simple aqueous solution method. Results showed that the ATH@ADP@MCA not only decreased the aggregation in EVA but also had superior fire retardancy for the improved char formation ability and dilution of flammable gases. Only 55 wt% ATH@ADP@MCA can endow EVA with satisfying flame retardancy such as the UL-94 V-0 grade and low heat release. Higher values of the fire performance index (0.28 m²s/kW) were also achieved by EVA with 55 wt% ATH@ADP@MCA compared with those of EVA with the same loading of neat ATH. Moreover, ATH@ADP@MCA enhanced tensile strength without sacrificing the elongation at the break of EVA. This study illustrates that the core-shell ATH@ADP@MCA has a broad potential for developing EVA composites with excellent flame retardant and mechanical properties.