含碳复合体系的流变学性质和导电性质

Rheological and Electrical Behavior of Carbon Materials Filled Composites

利用高级流变扩展系统研究了含碳复合体系的流变学性质随温度的变化关系。研究发现,在逾渗阈值前后复合体系的流变学行为表现出很大的差异,高温时复合体系的储能模量随填充浓度的增加而急剧增大,损耗因子在100℃附近出现峰,峰位随碳含量的增加向高温方向移动,当体系浓度在逾渗阈值以上时趋于平坦;直流电导率和交流电导率测量表明电导逾渗阈值和流变学逾渗阈值非常相近;最后尝试对不同温度下的电导率-频率曲线进行了叠加。

Temperature-dependent rheological properties of carbon materials filled composites were studied using advanced rheology expand system （ARES）. It is found that the rheological behavior of the composites is quite different at the concentration below and above the percolation thrdshold. The temperature dependence of storage modulus indicates that the incorporation of the particles results in a significant increase of the storage modulus. A loss factor peak is around 100 ℃ for neat HDPE and composites with low loadings. The peak shifts to higher temperature with the increase of the loadings and disappears when the filler concentration is above the percolation threshold. The direct current （DC） conductivity and alternating current （AC） conductivity measurement of the composites demonstrate that the electrical percolation threshold coincides well with the theological one. The temperature-independent master curves of normalized conductivity as a function of frequency was constructed. All of the conductivity data at different temperatures fall on one single curve.