低密度聚乙烯基复合导电材料的伏安特性

研究了碳黑含量为２３％～３０％的低密度聚乙烯（ＬＤＰＥ）－碳黑（ＣＢ）复合导电材料的直流Ｉ－Ｕ特性。结果表明，当外加电压小于曲线上的转变电压（或峰值电压）时，电流与电压的关系遵从欧姆定律，近似为一直线，在此区域内测量的体积电阻值重复性好。伏安特性曲线上的峰值电压随温度升高而降低，相对应的电流也减小。电流随时间的响应曲线表明，高电压下，经较长时间才能达到稳定的电流值，而低至１．５Ｖ时，电流几乎一直都是平稳的，测量结果的重复性较好。通过上述试验得到通常的体积电阻的测试条件，由体积电阻求出体积电阻率。

Current voltage Characteristics of LDPE Matrix Conductive Composites

It is found that the directcurrent I-U characteristics of LDPE composite containing CB 23%～30% can be divided into two regions, ohmic and non ohmic region, according to the peak (or transition) voltage of I-U curves. When an applied voltage is less than the peak voltage, the I-U behavior can be linearly expressed by ohms law. In the ohmic region a steady and repeatable bulk resistance is easily attainable. The peak voltages in the I-U curves decrease with temperatures increasing and the corresponding currents are also decreased. From the current time curves it is shown that under high voltages, a steady current can not be attained until a long time passes away, whereas when applied voltages are less than 1.5V, the current is always steady. Through the above experiments the testing conditions of bulk resistivity are obtained.