摘要：采用表面接枝改性的方法对碳化硅粉体进行表面改性。通过对3种改性粉的表面特性、分散稳定性能、流变性能进行比较,发现水杨酸和丙烯酰胺组合的改性剂对SiC微粉的改性效果优于单一体系。包覆后SiC粉的表面与流变特性发生很大的改变,其中水杨酸使其等电点向酸性方向移动,丙烯酰胺使其等电点向碱性方向移动,水杨酸和丙烯酰胺复合改性的SiC微粉,其等电点在两者之间移动,并在pH=12.5时,粉体有最大Zeta绝对值,Zeta电位由原始粉的30.5 mV提高到60.0 mV,所配料浆的固相含量达到57.0%(体积分数),料浆粘度为0.1 Pa.s。

关键词： 碳化硅；流变特性；包覆改性；表面结构

Abstract:The surface of SiC powder were modified by suface grafting method. By comparing surface characteristic, disperse stability and rheology of the three different kinds of modified SiC ultrafine powder, the effect of the compound modifying agent excelled that of salicylic acid and acrylamide were found. The effect law of modifying agent to ultrafine powder surface characteristic was studied. Being clad, surface and rheology characteristic of the SiC ultrafine powder change a lot, the salicylic acid can transfer the IEP of the powder to the acidity, the acrylamide can transfer the IEP of the powder to the alkalescence, the isoelectric point of the powder coated by them will move about the two isoelectric point, and the Zeta potential increased from 30.5 mV to 60.0 mV, solid phase volumecontent of the slime reached 57.0% and the viscosity was 0.1 Pa·s. 

Keywords: silicon carbide; rheological behavior; coat and modification; surface structure