纳米MH/AF/NBR复合材料物理力学性能及耐热阻燃机理

为了获得具有较好物理力学性能和耐热阻燃性能的橡胶密封材料,以NBR、芳纶纤维(AF)和纳米Mg(OH)₂(MH)为主要原料制备了纳米MH/AF/NBR复合材料.研究了纳米MH和AF不同配比时,复合材料的物理力学性能变化、耐热阻燃性能变化.结果表明:纳米MH对复合材料内部结构有很好的补强作用,而AF添加量较多时,与橡胶的结合强度有变差的趋势.不同配比的纳米MH与AF能够有效改善NBR的物理力学性能.当纳米MH与AF填料配比份数配比为20/10时,复合材料的拉伸强度、定伸应力可以提高4%左右,永久压缩变形降低1%左右,当纳米MH/AF份数配比为30/10时,硬度提高到73度.比较发现纳米MH的阻燃性能要优于AF,纳米MH/AF份数配比为10/10时,复合材料分解温度提高了近20℃,MH/AF填料的加入改善了NBR原有的热稳定性,且复合材料燃烧时烟气生成量较小,为该类复合材料在密封等领域进一步应用奠定了基础.

Physico-mechanical properties and heat-resistant mechanism of nano-MH/AF/NBR composite

In order to produce a rubber sealing material with satisfactory physical and mechanical properties, heat resistance, and flame retardance, a nano MH/AF/NBR composite material was made by using nitrile butadiene rubber (NBR), aramid fiber (AF), and nano magnesium hydroxide (MH). Physical and mechanical performance, heat resistance, and flame retardance of the composite material were investigated for different proportions of nano MH and AF. Nano MH reinforced the internal structure of the composite material. The bond strength between AF and rubber matrix decreased with increasing amount of AF in the composite. When MH/AF ratio was 20/10,the stress at definite elongation and tensile strength were increased by 4%, and compression set was reduced by 1%. When MH/AF ratio was 30/10, hardness increased to 73 degree. The nano MH/AF composite had good flame retardance and improved thermal stability of NBR. Additionally, the total smoke production of the composite material was reduced. The results established a foundation for further applications using the nano MH/AF/NBR composite material as a sealant.