结构化控制剂种类及配比对硅橡胶性能的影响

Effect of type and proportion of structure control agents on properties of silicone rubber

以甲基乙烯基硅橡胶为生胶、2,5-二甲基-2,5-双(叔丁基过氧基)乙烷为硫化剂,通过添加白炭黑和结构化控制剂并采用二段硫化工艺制得热硫化硅橡胶,研究了结构化控制剂种类及并用比例对热硫化硅橡胶力学性能和耐热性能的影响。结果表明,端羟基甲基苯基硅油(OH-PMPS)的加入对硅橡胶的硬度、撕裂强度、回弹性和耐热性能有较大的提升,但是当其用量过大时会导致硅橡胶的强度有所下降;而六甲基二硅氮烷(HMDS)与羟基硅油(OH-PDMS)的加入分别有助于提高材料的拉伸强度和扯断伸长率,当HMDS用量为4份、OH-PDMS和OH-PMPS用量均为2份时,对硅橡胶综合性能的提升效果最佳。

The heat curing silicone rubber was prepared with methyl vinyl silicone rubber as raw rubber and 2,5-dimethyl-2,5-di(tert-butylperoxy)hexane as curing agent by the additon of silica and structural control agents via two-stage vulcanization.The effects of the type and combined proportion of structure control agents on the mechanical properties and heat resistance of heat curing silicone rubber were studied.The results showed that the addition of hydroxymethyl phenyl silicone oil(OH-PMPS)could greatly improve the hardness,tear strength,rebound resilience and heat resistance of silicone rubber,but when the amount of OH-PMPS was too large,the tensile strength of silicone rubber would decrease.However,hexamethyldisilazane(HMDS)and hydroxyl silicone oil(OH-PDMS)could improve the tensile strength and elongation at break of the materials,respectively.When the amount of HMDS was 4 phr and the amount of OH-PDMS and OH-PMPS was both 2 phr,the comprehensive performance of silicone rubber was better.