苯基含量对硅橡胶性能的影响

Effect of phenyl content on properties of silicone rubber

为了获得-71~60℃范围内剪切性能稳定的柔性接头弹性材料,研究了苯基含量对甲基乙烯基硅橡胶性能的影响。结果表明,随着苯基含量的增加,混炼胶正硫化时间(T_(90))和扭矩缓慢升高,室温下硅橡胶断裂伸长率降低较快,撕裂强度轻微增加,但拉伸强度和剪切强度变化不明显,低温下硅橡胶玻璃化转变温度升高,结晶性能得到明显改善,低苯基硅橡胶在-71℃的拉伸耐寒系数达到0.94;硅橡胶在-71~60℃范围内剪切性能分析表明,甲基乙烯基硅橡胶剪切模量在-71℃时急剧增大,低苯基硅橡胶在宽温域范围内剪切模量波动较小,但中苯基硅橡胶剪切模量变化较大。

In order to obtain a flexible joint elastomeric material with stable shear properties in the range of -71℃to 60℃,in this paper,the effect of phenyl content on the properties of methyl vinyl silicone rubber was studied.The results showed that with the increase of the content of phenyl groups,the vulcanization time T90 and torque of the composites increased,the elongation at break of silicone rubber decreased faster at room temperature,the tear strength increased slightly,but the tensile strength and shear strength did not change obviously.Also,the glass transition temperature of silicone rubber at low temperature increased,and the crystallization behavior improved obviously.The drawing cold-resistant coefficient of low-phenyl silicone rubber at -71℃ was 0.94.The shear property of silicone rubber at -71℃to 60℃showed that the shear modulus of methyl vinyl silicone rubber increased sharply at -71℃,and the fluctuation of volume of the shear modulus of low-phenyl silicone rubber in wide temperature range was small and the shear modulus of medium-phenyl silicone was changed greatly.