硅灰石表面有机改性及性能表征

利用干法工艺改性法库地区硅灰石，研究了改性剂种类及用量、改性温度和改性时间对改性效果的影响。借助接触角测量仪、X射线衍射仪、红外光谱、热重分析和扫描电子显微镜表征改性前后硅灰石的性能。结果表明，适宜的改性剂为KH-570，最佳改性工艺为改性剂用量3%（占粉体总质量），改性温度80℃，改性时间40 min。最佳条件下，改性硅灰石的接触角为109.186°，活化指数为99.97%。表面改性过程对硅灰石的物相组成、化学结构、热分解和形貌没有明显影响。KH-570改性硅灰石的实质为KH-570水解生成硅醇或硅羟基，包覆在硅灰石表面，从而使得硅灰石表面由亲水性变为疏水性。 

Surface Organic Modification and Characterization of Wollastonite

Surface modification of wollastonite with dry-modification method was investigated. The influences of type and dosage of surface modifier, modification temperature and time on modification effect of wollastonite were studied. Modified wollastonite powders were characterized by contact angle measuring instrument, X-ray diffraction, Fourier transform infrared spectroscopy, thermogravimetric analysis and scanning electron microscopy. Results showed that the suitable modifier was KH-570 and the optimum condition was modifier dosage of 3%(in mass), modification temperature of 80 ℃ and time of 40 min. Under the optimum condition, contact angle of modified product was 109.186° and activation index was 99.97%. There was no obvious effect of surface modification on the phase composite, chemical structure, thermal decomposition and morphology of wollastonite. The mechanism of KH-570 modified wollastonite could be explained as follow. The KH-570 was hydrolyzed silanol or silanol groups, which could coat on the surface of wollastonite. As a result, the surface of wollastonite transformed from hydrophilic to hydrophobic.