球形二氧化硅颗粒表面的疏水改性及其性能研究

Study on Hydrophobic Modification and Property of Spherical Silicon Dioxide Particle

比较了硬脂酸钠、四乙氧基硅烷以及乙烯基烷氧基硅烷/丙烯酸缩水甘油醚复合改性球形SiO2的改性效果。对改性前后SiO2颗粒样品的接触角、含水率、吸油值以及环氧树脂分散液黏度的测定结果表明:不同类型的改性剂都能不同程度地提高SiO2表面的疏水性,其中复合改性后SiO2样品的亲油性得到明显改善。同时用扫描电子显微镜对固化后的复合材料断面观察发现:复合改性SiO2颗粒与环氧树脂间的界面模糊,表明其亲合性明显优于未改性SiO2。复合材料的力学性能测试结果表明,复合改性SiO2复合材料的拉伸强度增加了35%,弯曲强度增加了42%,而硬脂酸钠改性却弱化了界面作用,复合材料的强度有所下降。

The hydrophobicity of spherical silicon dioxide surface-modified by different agents such as sodium stearate （NaSt）, tetraethoxy-silicane （TEOS）, vinyl trialkoxysilane and glycidyl acrylat （GA） was discussed. The measurements of the contact angle, water content, oil absorption of the modified samples and the viscosity of SiO2/ EP dispersion solution showed the hydrophobic property of the SiO2 particles was improved to certain degree after the modifications, especially after GA modified. The SEM result indicated that the affinity between modified SiO2 particle and epoxy resin was better than that between unmodified SiO2 particle and epoxy resin. Compared with others the measurement of the mechanical properties of SiO2 modified by GA and epoxy resin compound showed the tensile strength of the compound increased by 35 %, bending strength increased 42 %, while NaSt weaken the inerface reaction between SiO2 particles and epoxy resin, which led to the decrease of the tensile strength of the compound.