球磨作用对改性二氧化硅热行为的影响

对天然二氧化硅分别经不同条件球磨改性,并分别采用TGA、X射线衍射分析、红外光谱分析和粒度分析等对改性二氧化硅样品进行表征,研究了球磨作用对改性二氧化硅热行为的影响.结果表明,在TGA曲线上,原料二氧化硅失重率很低,而球磨后二氧化硅失重率都较大.从TGA曲线可知,经球磨后硅烷偶联剂KH-560并不是简单的物理吸附而是化学吸附于改性二氧化硅表面.结构表征结果表明,不同球磨条件下所得改性二氧化硅的结构有显著差异.因此,不同球磨条件下所得改性二氧化硅的热行为差异主要是由相应改性二氧化硅的结构变化差异所引起的.

Effect of ball milling on thermal behaviors of modified silicon dioxide

Modified silicon dioxides were obtained by ball milling under different grinding conditions,and were characterized using thermogravimetric analysis(TGA),X-ray powder diffraction analysis (XRD),FT-IR spec- tra analysis and particle size analysis.It is found that there is no mass loss on the TGA curve of silicon dioxide raw material,but there is an apparent mass loss on the TGA curve of ball-milling silicon dioxide.The results from TGA curves indicate that silane coupling agent KH-560 is not physically absorbed but chemically absorbed onto the surface of modified silicon dioxide after ball-milling.The results from structural analysis indicate that the structures of different modified silicon dioxide are quite different.Therefore,the differences between the thermal behaviors of modified silicon dioxide are consistent with the differences between the structures of corre- sponding modified silicon dioxide.