正硅酸乙酯对废弃轮胎胶粉的改性研究

Modification of Waste Tire Rubber Powders with Tetraethoxysilane

以正硅酸乙酯为硅源,采用溶胶-凝胶法对废弃轮胎胶粉进行表面改性,探讨改性条件对改性效果的影响,通过活化指数、接触角、红外光谱、热分析和扫描电镜等手段对改性前后的胶粉进行表征,并讨论改性机理。结果表明,在室温下,正硅酸乙酯与胶粉的质量比为1∶2,反应时间为6 h时改性效果最佳;改性后胶粉表面生成一层SiO2无机网络结构,平均接触角从96°减小到23°,其表面由疏水性变为亲水性。

The surface modification of waste rubber powders by sol-gel method with tetraethoxysilane was investigated. The modification effects were characterized by the means of activation indexes, angles of contact, IR, TG and SEM. The modification mechanism was discussed. The results show that when the mass ratio of tetraethoxysilane and waste rubber powders is 1：2, the reaction time is 6 h, the modification effect is best. A layer of inorganic network structure of SiO2 is generated on the surface of modified waste rubber particles. The contact angle of the modified waste rubber powders with water decreases from 96 to 23° at room temperature, which indicates that the surface of waste rubber powders changes from hydrophobic to hydrophilic.