CO2处理对N990炭黑及其复合材料电性能的影响

Effect of CO2 Treatment on the Electrical Conductivity of N990 Carbon Black and Its Composites

以高温CO2处理的改性N990炭黑与PE-HD熔融混合制备正温度系数（PTC）电阻（率）复合材料。采用氮气吸附比表面积、扫描电镜和x射线光电子能谱表征处理炭黑的结构，研究CO2处理对N990炭黑的结构和导电性及其复合材料P-FC特性的影响。结果表明，CO2处理后的N990炭黑内部结构基本不变，导电率可增加1倍以上，比表面积增加4倍以上，表面10-30A孔径的孔容增加6倍以上，表面的氧元素含量下降36．6％。CO2处理PE—HD／N990炭黑复合材料的电阻率比未处理的下降了0.6-3个数量级，PTC强度下降了0～60．1％，但适当选择处理的N990炭黑含量的复合材料同时具有低的室温电阻率和较高的PTC强度。

Modified carbon black was obtained by treating N990 in CO2 at high temperature, and its PE- HD composites were then prepared. Treated carbon blacks were characterized with BET, SEM and XPS. The effect of CO2 treatment on the structure and electric property of N990, as well as PTC properties of its composites were investigated. The results show that treated carbon black, as compared with the untreated one, keeps its original inner structure, but can increase its conductivity by more than 1 time, nitrogen surface area by more than 4 times, new pores within 10-30A in size by more than 6 times on its surface, and decreases its surface oxygen by 36.6 %. Room resistivity of treated N990 composite can decrease by 0.6 to 3 orders of magnitude compared with that of the untreated one, though PTC intensity also deceases by zero to 60.1%. However, composites exhibiting low room resistivity and relative high PTC intensity can be attained by loading suitable weigh of treated N990.