膨胀石墨对乙烯基硅橡胶的阻燃作用研究

将可膨胀石墨（EG）添加到乙烯基硅橡胶中并采用过氧化物硫化制备了硅橡胶材料，对其阻燃性能和燃烧行为进行了研究。结果表明，当EG的添加量为5份时，材料在垂直燃烧测试中通过了UL 94 V?0级，且能离火自熄，极限氧指数达到了33.0 %；与纯硅胶材料相比，EG的加入有效降低了材料的热释放和烟释放；材料与火焰接触区域，EG完全膨胀并形成了隔热层，火焰附近材料内部的石墨得到了一定程度的膨胀并形成了导热通路，将材料的热量扩散，从而对硅橡胶材料起到了优异的阻燃作用。

Effect of expandable graphite on flame retardant performance of vinyl silicone rubber

Silicone rubber （SR） composites were prepared by the incorporation of expandable graphite （EG）， followed by curing with peroxide， and their flame?retardant performance and combustion behavior were investigated. The results indicated that the SR composites containing 5 phr EG reached a UL 94 V?0 rating in the vertical burning tests， and their limited oxygen index value reached 33.0 vol%. The cone calorimeter test resulted demonstrated that the addition of EG suppressed the release of heat and smoke effectively. The mechanism of flame retardant was studied， which indicated that the EG distributed on the materials surface expanded completely and generated a heat insulation layer. Meanwhile， the inner EG expanded to a certain extent and produced a sufficient thermal conductive path to dissipate the heat of materials. Consequently， the SR composites were endowed with excellent flame retardant performance due to the introduction of EG.