Investigation on Flame Retardancy and Mechanical Property of Chemical Cross-linked EVA/NBR Composites

In this paper,halogen free flame retardant EVA/NBR composites containing magnesium hydroxide[Mg(OH) 2 ]and red phosphorus(RP)were prepared via melt blending through a two-roll mill.Limiting oxygen index,cone calorimeter,tensile test,and thermal gravimetric analysis were used to characterize the effect of dicumyl peroxide(DCP)and maleic anhydride grafted ethylene-vinyl acetate copolymer(EVA-g-MAH)on the flammability,mechanical properties,and thermal behavior of EVA/ NBR composites.The limiting oxygen index value reached 38.4 % and the heat release rate decreased from 941to 690kW/m2;the tensile strength reached 17.4 MPa,and elongation at break increased to 1236%;the starting mass loss temperature increased from 321.6to 327.0 ℃,and the residual mass increased from 10 % to 32.1 % at the presence of 10phr EVA-g-MAH after cross-linking.The morphology of cryogenically fractured surface was observed and analyzed using scanning electron microscope(SEM)and it showed that the fractured surface was compact and fillers disperse evenly.