纳米SiO2表面接枝及其在原位乳液聚合体系中的分散稳定性

用湿法改性方法将硅烷偶联剂接枝在纳米SiO2表面上,并分析了pH值、反应时间、反应温度及硅烷偶联剂的加入量对接枝效果的影响,继而讨论了接枝后的纳米SiO2在原位乳液聚合过程中的分散稳定性.结果表明,较佳的改性工艺条件为:pH值为3~4,反应温度为80℃,反应时间为120 min,硅烷偶联剂的加入量为纳米SiO2重量的10%左右.接枝了硅烷偶联剂的纳米SiO2,能够使乳化剂聚集在其表面上,形成“胶束”区域,从而提高了在乳液聚合体系中的分散性和稳定性.

Graft of Nano-Silica and its Dispersion Stability in the in-suit Emulsion Polymerization

By applying the wet technique of particle modification,silane coupling agent was grafted on the surface of nano-silica.The effects of reaction processing parameter on the graft ratio and its dispersion stability in the in suit emulsion polymerization were discussed.In the result,the proper pH,reaction temperature,reaction time and the addition of silane coupling agent of reaction were obtained.After grafting with silane coupling agent,micelles were generated on the surface of nano-silica through the absorption of emulsifying agent,which improved the dispersion stability of nano-silica in the emulsion polymerization system.