化学交联EVA/NBR阻燃复合材料的燃烧行为及力学性能

以乙烯-醋酸乙烯共聚物（EVA）/丁腈橡胶（NBR）为主体，氢氧化镁Mg(OH)2）]和红磷（RP）为阻燃剂制备了无卤阻燃EVA/NBR复合材料，通过力学性能测试、热重分析以及燃烧行为表征（极限氧指数和锥形量热分析）研究了交联剂过氧化二异丙苯（DCP）以及马来酸酐接枝乙烯-醋酸乙烯共聚物（EVA-g-MAH）对EVA/NBR复合材料的力学性能、热稳定性和阻燃性能的影响。结果表明，含有10份相容剂EVA-g-MAH的交联材料，其拉伸强度可达到17.4 MPa，断裂伸长率可达到1236 %；材料的热分解温度从321.6 ℃提高到327.0 ℃,残炭量从10 %提高到了32.1 %；极限氧指数达到33.5 %且热释放速率峰值从941 kW/m2降到了690 kW/m2；通过扫描电子显微镜对复合材料的断面形貌进行了观察分析，发现材料断裂表面填料分散均匀。

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 941 to 690 kW/m2; the tensile strength reached 17.4 MPa, and elongation at break increased to 1236 %; the starting mass loss temperature increased from 321.6 to 327.0 C, and the residual mass increased from 10 to 32.1 % at the presence of 10 phr 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.