活性硅酸钙粉体改性及其增强硅橡胶性能研究

Active Calcium Silicate Powder Modification and Enhancement of the Properties of Silicone Rubber

采用水热法对活性硅酸钙粉体进行表面改性,将改性后的粉体加入到硅橡胶中制成复合材料,通过吸油值、红外光谱、扫描电镜和热重分析等手段对样品进行分析和表征。结果表明,粉体表面成功接枝硬脂酸分子链,改性剂用量增加,粉体吸油值降低,硬脂酸和粉体间存在化学吸附。添加1%硬脂酸可以使硅橡胶拉伸强度比未改性粉体增加40%。硬脂酸用量从1%增加至8%,拉伸强度降低,扯断伸长率先增加后降低,硬脂酸用量为4%时,扯断伸长率达到最大,硬脂酸用量为8%时,拉伸强度和扯断伸长率最低。

Active calcium silicate powder were surface modified by hydrothermal method, then were added to prepare composite material. The samples were characterized by oil absorption, IR, SEM and DSC-TG. The results show that stearic acid molecular chain is grafted on the powder surface, and oil absorption value of powder decreased with modifier dosage increasing. There exists chemical adsorption between stearic acid powders. The effect of mass fraction of 1% stearic acid can make the tensile strength of silicone rubber increase 40% than the unmodified powder .When the dosage of stearic acid increases from 1%o to 8%, tensile strength decreases, elongation at break increases and reaches the maximum at 4%. Tensile strength and elongation at break is the lowest when the dosage of stearic acid is 8%.