碳酸钙疏水改性及性能表征

Hydrophobic modification and characterization of calcium carbonate

采用单一改性剂油酸、硬脂酸、二甲基硅油及复合改性剂对碳酸钙颗粒进行疏水改性。介绍了改性碳酸钙的作用机理。探讨了改性剂种类和加入量对碳酸钙颗粒表面疏水程度的影响,并通过活化度表征疏水程度。采用红外光谱仪表征改性前后碳酸钙的结构,说明改性剂被引入到了碳酸钙颗粒表面上;采用Zeta电位仪测定改性前后碳酸钙随pH变化的Zeta电位,得知改性碳酸钙的Zeta电位受pH影响比较大;采用激光粒度仪测定改性前后碳酸钙的粒径,得知改性碳酸钙比未改性碳酸钙的平均粒径小,且其分散稳定性要优于未改性碳酸钙。该研究也提供了随改性剂种类和加量变化来调整颗粒表面疏水程度的方法,有一定实际意义。

Calcium carbonate particle was modified into hydrophobe with single modifying agent oleic acid, stearic acid, simethicone,and compound modifying agents.The mechanism of calcium carbonate modification was introduced.The influences of sorts and dosages of modifiers on hydrophobic degree were discussed ,and the hydrophobic degree was characterized with the activation degree.The structures of modified and unmodified calcium carbonate were characterized by infrared spectrometer, and the results showed that modifiers were introduced onto the surface of calcium carbonate particles. The Zeta potentials of modified and unmodified calcium carbonate were analyzed by zeta potentiometer with different pH, and the results showed the Zeta potentials of the modified calcium carbonate was sharply influenced by pH.The particle sizes of modified and unmodified calcium carbonate were analyzed by laser particle size analyzer,and the results showed the average particle size of the modified calcium carbonate was smaller than that of unmodified one, and its dispersion stability was superior to the unmodified one.The study also provided a method with the change of modifying agent＇s types and dosages to adjust hydrophobic degree of the surface of calcium carbonate particles, which had a certain practical significance.