The Effect of Metal Oxide and Polycarbosilane on Flame Retardancy and Combustion Behavior of Eva/MH Composites

ABSTRACT Low smoke halogen‐free flame retardant ethylene‐vinyl acetate copolymer (EVA) composites with magnesium hydroxide (MH) as a flame retardant have been widely used in wire and cable, electrical equipment, and other fields; however, the overall performance of the composites is very difficult to regulate due to the low flame retardancy of MH. In this work, the metal oxides (ferric oxide Fe 2 O 3 and nickel oxide NiO) together with polycarbosilane, were added in EVA/MH composites; the flame retardancy and combustion behaviors were evaluated, and the thermal degradation behavior and the gaseous product of the composites were studied. The results show that Fe 2 O 3 or NiO, together with PCS, exhibits a synergistic effect in EVA/MH composites; the oxygen index increased by 154.9% and 135.3%, respectively, and the total heat release decreased by 20.4% and 11.3%, respectively. The synergistic effect between metal oxide and PCS is well reflected in the combustion process of the composites; the suppression of combustion depends on the further improved barrier effect of the residue by metal oxide.