辐照交联对膨胀阻燃剂/乙烯-辛烯共聚物复合材料力学性能及阻燃绝缘性能的影响

Mechanical and flame retardant insulation properties of radiation-crosslinked on intumescent flame retardants/POE intumescent flame retardant material

采用机械共混法向乙烯-辛烯共聚物中添加不同含量的膨胀阻燃剂(聚磷酸铵、季戊四醇、三聚氰胺),然后采用电子束辐照,制备出交联型膨胀阻燃复合材料。通过极限氧指数、热失重、燃烧性能等参数表征电子束辐照交联对其阻燃性能的影响。结果表明,辐照交联后,复合材料的氧指数提高1~2;对力学性能而言,断裂伸长率随着吸收剂量的增加呈现下降趋势,拉伸强度则呈现上升趋势;对热释放的影响,复合材料的燃烧过程缩短,释热、释烟更为集中,在200 kGy吸收剂量下辐射交联后,总热释放量由94.8 MJ/m^2下降至79.1 MJ/m^2,总烟释放量由1 122.9 m^2/m^2下降至928.4 m^2/m^2,燃烧过程缩短约25%,CO释放率由0.062 2kg/kg下降至0.043 9 kg/kg,CO_2生成率由1.44 kg/kg上升至1.51 kg/kg;对绝缘性能而言,随着吸收剂量的增加,材料的体积电阻率变化幅度很小,提示辐照对材料的绝缘性能影响很小。

Ethylene-octene copolymer（POE） blended with different contents of intumescent flame retardants（ammonium polyphosphate, pentaerythritol, and melamine） was irradiated by electron beams to prepare flame retardant composite materials. The oxygen index, cone calorimeter, and combustion performance were used to characterize the flame retardant properties. The results showed that the tensile strength as well as the oxygen indices of the composites（about 1～2） increased and the elongation at break decreased with increasing absorbed doses. The combustion process of the composites shortened, and the heat and smoke release of the composites were more concentrated. After irradiation crosslinking at 200 k Gy, the total heat release decreased from 94.8 MJ/m^2 to 79.1 MJ/m^2, the total amount of smoke release decreased from 1122.9 m^2/m^2 to 928.4 m^2/m^2, the combustion process reduced by about 25%, the CO release rate decreased from 0.062 2 kg/kg to 0.043 9 kg/kg, and the CO2 producing rate increased from 1.44 kg/kg to 1.51 kg/kg. Moreover, as the absorbed dose increased, the volume resistivity of the material varied slightly.