补强剂和硫化剂对硅橡胶胶料耐热氧老化性能的影响

Effect on Reinforcing Agents and Vulcanizing Agents on Thermal-Oxidative Aging Resistance of Silicone Rubber Compounds

以甲基乙烯基硅橡胶(以下简称硅橡胶)为主体材料,气相法白炭黑或沉淀法白炭黑为补强剂,硫化剂双25或铂金硫化剂为硫化剂,研究补强剂和硫化剂对硅橡胶胶料耐热氧老化性能的影响。结果表明:补强剂对硅橡胶胶料的耐热氧老化性能的影响更显著。随着老化时间的延长,气相法白炭黑补强的硅橡胶胶料的交联密度呈现增大的趋势,硬度增大,拉伸强度先增大后减小,拉断伸长率减小;沉淀法白炭黑补强的硅橡胶胶料的交联密度先减小后增大,硬度、拉伸强度、拉断伸长率均呈减小趋势,综合而言,沉淀法白炭黑补强的硅橡胶胶料的耐热氧老化性能略优。使用不同硫化剂的硅橡胶胶料热氧老化前的性能相当,热氧老化后,与使用硫化剂双25的硅橡胶胶料相比,使用铂金硫化剂的硅橡胶胶料的交联密度和硬度略小,拉断伸长率增大,耐热氧老化性能略优。

Taking methyl vinyl silicone rubber(hereinafter referred to as silicone rubber)as the matrix,fumed silica or precipitation silica as the reinforcing agent and vulcanizing agent double 25 or platinum vulcanizing agent as the vulcanizing agent,the effects of reinforcing agents and vulcanizing agents on the thermal-oxidative aging resistance of silicone rubber compounds were studied.The results showed that the reinforcing agent had a more significant effect on the thermal-oxidative aging resistance of silicone rubber compounds.With the extension of aging time,the cross-linking density of fumed silica reinforced silicone rubber compound showed an increasing trend,the hardness increased,the tensile strength increased first and then decreased,and the tensile elongation at break decreased.The cross-linking density of precipitation silica reinforced silicone rubber compound first decreased and then increased,while the hardness,tensile strength and tensile elongation at break all showed a decreasing trend.Overall,the thermal-oxidative aging resistance of precipitation silica reinforced silicone rubber compound was slightly better.The performance of silicone rubber compounds using different vulcanizing agents before thermo-oxidative aging was equivalent.After thermo-oxidative aging,compared with the vulcanizing agent double 25 vulcanized silicone rubber compound,the cross-linking density and hardness of the platinum vulcanizing agents vulcanized silicone rubber compound were slightly smaller,the tensile elongation at break increased,namely,the thermal-oxidative aging resistance was slightly better.