氢氧化铝复合阻燃剂对热硫化硅橡胶性能的影响

研究了氢氧化铝、氢氧化铝／三氧化二锑并用、氢氧化铝／三氧化钼并用对热硫化(HTV)硅橡胶阻燃性能和力学性能的影响；试图在力学性能与阻燃性能之间寻找平衡。结果表明：当100份硅橡胶中氢氧化铝的用量为80份时，硅橡胶的燃烧氧指数(OI值)可达30％，但力学性能却受到严重损害，发烟量为B级；氢氧化铝／三氧化二锑并用时，HTV硅橡胶的性能较理想；当(氢氧化铝 三氧化二锑)用量为50份时，硅橡胶的OI值为31％、拉伸强度为6．3MPa、扯断伸长率为660％、撕裂强度为23．7kN／m、邵尔A硬度为57度，但发烟量为C级；氢氧化铝／三氧化钼并用可使HTV硅橡胶燃烧时的发烟量达到A级，但不能显著提高其阻燃性能，当(氢氧化铝 三氧化钼)用量为96份时，HTV硅橡胶的OI值仅28％，且此时其力学性能受到较大损害。

Effect of Al(OH)3 on the flame-retarded property of RTV silicone rubber

The effects of flame-retardants,which were Al(OH) 3 ,the blend of Al(OH) 3/Sb 2O 3 ,the blend of Al(OH) 3/MoO 3 ,on the flame-retarded properties of heat vulcanized (HTV)silicone rubber were studied,respectively,trying to seek the balance between the mechanical properties and flame-retarded properties.The results showed that the flame-retarded properties of silicone rubber could be improved and its oxygen index (OI) could reach 30%,yet its mechanical properties could be severely damaged with Class B fuming if Al(OH) 3 was 80 phr.When adding the blend of Al(OH) 3/Sb 2O 3 the property of silicone rubber was relatively ideal and when the blend of Al(OH) 3/Sb 2O 3 was 50 phr,the OI,tensile strength,elongation at break,tear strength and shore A hardness of HTV silicone rubber were 31%,6.3 MPa,660%,23.7 kN/m and 57 respectively,the level of smoke was C.Although the blend of Al(OH) 3/MoO 3 could effectively diminish the amount of smoke from C to A,it couldn't improve the flame-retarded property of silicone rubber,whose OI was 28,and badly damaged its mechanical properties.