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在醇水混合溶剂中利用超声波促进气相白炭黑表面接枝环氧硅氧烷,制备纳米SiO_2-环氧杂化树脂。以激光粒径分析仪、红外光谱、热重分析、旋转黏度计、高氯酸环氧测定法表征合成产物。研究环氧硅氧烷/气相SiO_2质量比及超声时间对产物环氧值及接枝效率的影响。超声波能有效打开白炭黑的次级粒子,经原生粒子表面羟基的缩合反应,接枝环氧基团;杂化树脂的环氧值随环氧硅氧烷/气相SiO_2质量比、超声时间的延长而增加;在8%硅氧烷溶液于70℃超声处理20 min,接枝效率达72%,SiO_2表面羟基接枝率为17%;平均每颗SiO_2粒子表面接枝8×103个环氧基,得环氧值为0.02的杂化树脂。接枝的环氧基团可有效减小气相SiO_2的触变性。
In the mixed solvent of alcohol and water, ultrasound is used to promote the grafting of epoxy siloxane on the surface of fumed silica to prepare nano-SiO 2 -epoxy hybrid resin. The synthesized products were characterized by laser particle size analyzer, infrared spectroscopy, thermogravimetry, rotational viscometer and perchloric acid epoxy determination. The effects of epoxy siloxane / gas phase SiO 2 mass ratio and ultrasonic time on epoxy value and grafting efficiency were studied. Ultrasound can effectively open the secondary particles of silica, through the condensation reaction of hydroxyl groups on the surface of the primary particles, grafted epoxy groups; the epoxy value of the hybrid resin with epoxy siloxane / gas phase SiO 2 mass ratio, ultrasonic time The results showed that the grafting efficiency was 72% when the 8% silicone solution was sonicated at 70 ℃ for 20 min, and the grafting rate of hydroxyl groups on the surface of SiO 2 was 17%. On average, 8 × 103 epoxy groups were grafted on the surface of SiO 2 particles Base, epoxy value of 0.02 to obtain a hybrid resin. The grafted epoxy groups can effectively reduce the thixotropy of vapor phase SiO_2.