无宏观缺陷水泥基复合材料的介电性能

Dielectric Properties of Macro-defect-free Cement Based Composites

在 1 0 2 ～ 1 0 7Hz频率范围内测定了酚醛树脂 -高铝水泥基无宏观缺陷 (MDF)材料的介电常数和介电损耗随材料组成及环境湿度的变化曲线 .结果表明 ,MDF材料的介电常数和损耗皆与测试频率有关 ,介电损耗由载流子屏蔽跳跃引起 .当材料内酚醛树脂的数量增加时 ,介电常数下降而损耗略有上升 ,添加硅灰能显著改善材料介电性能 ;在低相对湿度下 ,湿度对介电性能影响不大 ,在高相对湿度下 。

The dielectric constant and loss factor of phenol resin-high alumina MDF composites as a function of their composition and relative humidity are determined at the frequency range from 10 2 to 10 7 Hz. The test results show that the dielectric constant of the composites decreases with increasing the content of phenol resin while the loss factor increases slightly. Both dielectric constant and loss factor increase seriously with increasing relative humidity. Silica fume can contribute to improve the dielectric properties of the composites.