Hot stretching ratio ( hsr ) was maintained at 3 . 96 , cb content was changed . the results indicate that when the cb content increases , the room temperature resistivity of composites decreases . at the cb content of 12phr , the room temperature resistivity of blends sharply reduces , and composites change from insulator to conductor , the value is entitled the percolation threshold ; at the cb content of 20phr , the room temperature resistivity of composites achieves 10 ~ ( 2 ) cm 结果表明:随炭黑含量增加，复合材料的体积电阻率降低，当炭黑含量达到12phr ( phr指每一百份树脂中所含填充物的重量份数)左右时，复合材料的体积电阻率急剧下降，此时一复合材料由绝缘体向导体转变，这个值被称为逾渗阀值;当炭黑含量到20phr时，复合材料的体积电阻率达到1 。
The regressive equation that described the relationship between resistivity and strain are determined . to prove the applicability of the relationship , we composite the conductive composite material prepared by chopped carbon fiber mat with glass fiber reinforced composites of different strain character and study the relations of strain to resistivity under tensile stress 为证实该关系的适用性，通过将短切碳纤维毡制备的导电复合材料与具有不同应变性能的玻璃钢复合，对拉伸状态下应变与体积电阻率之间的变化关系进行了研究，并用多元回归的方法进行了数值分析，确定了电阻率与应变之间变化的数学模型。
Tensile properties and impact properties measurements were done at room temperature . the volume resistivity of rectangular samples was measured using a zc36 electrometer and a high 240a voltage supply , for samples with a low resistivity level a dt - 9205b digital multimeter was used , silver paint was applied to ensure complete contact between sample and electrodes , namely , to eliminate the contact resistance . the phase morphology of blends was also studied using a jeol jsm - 5900lv scanning electron microscope ( sem ) 体积电阻率的测定：当r _ v 10 ~ 8时，制成100 100 4mm板材，用zc36型高阻仪测量；当r _ v 10 ~ 8时，用dt - 9205b型数字式万用表测试试样的体积电阻，为了减小接触电阻对测试的影响，采用银导电胶将铜片粘接在试样的两个端面上，静置24小时，待银导电胶凝固，试谢长琼:热拉仲对pet / pe / cb复合导电体系形态和性能的影响样的电阻稳定后再测量。
