摘要
采用AR500流变仪,测量了气相法制备的二氧化硅的环氧填料体系的剪切弹性模量G′、剪切粘性模量G″及其随角频率ω的变化曲线。发现当气相二氧化硅质量分数较小时,lgG′,lgG″lgω相互关系基本上呈直线,在高频部位lgG′,lgG″开始微微向下偏离直线形态;随着气相二氧化硅质量分数的增加,直线整体向上平移的同时斜率降低。从分子物理学观点分析认为,气相二氧化硅的增稠性和触变性可以归因于气相二氧化硅原始颗粒表面氢键的相互作用以及与环氧分子之间的作用,引入氢键效应建立理论模型,推得的数学公式拟合了实验曲线。
Shear elastic and viscous modules (G′ and G″) of an epoxy/filler system with fumed silica were measured by a rheometer modeled AR500 at different angular frequencies ω. The results indicate that lgG′-, lgG″-lg ω relationship curves look as straight lines on the double logarithmic scale at lower mass fraction of fumed silica. In the higher angular frequency region, there is a slight downward discrepancy for the curves from the straight line. With the increase of the fumed silica mass fraction the lines are upward translation, but the slopes decrease. Through an analysis from molecular physics viewpoint, it is proposed that the thickening property and thixotropy of the silica are in cause of the mutual effect of hydrogen bonding among the surface of primary fumed silica particles and with the molecule of epoxy polymers. From the theoretical model that includes the hydrogen bond effect, formulae is derived which is well fitted with the tested data.
出处
《硅酸盐学报》
EI
CAS
CSCD
北大核心
2005年第5期547-552,共6页
Journal of The Chinese Ceramic Society
关键词
气相二氧化硅
环氧填料体系
流变性
Curve fitting
Elastic moduli
Fillers
Hydrogen bonds
Molecular physics
Rheology
Silica
