PAN碳纤维的介电、半导体行为及其表征

SEMICONDUCTOR/DIELECTRIC BEHAVIOR AND CHARACTERIZATION OF POLYACRYLONITRILE (PAN) CARBON FIBER

用2801西林电桥研究了0℃～160℃聚丙烯腈(PAN)碳纤维的介电损耗因数ε、介质损耗角正切tgδ的频率特性;用微电导测试仪研究了温度、电场对PAN碳纤维的电导率γ的影响。

In this paper, dielectric and semiconductor behaviors of PAN carbon fiber have been analyzed by means of Tettex bridge(type 2801),microconductor analyzer(type 2C-36). The results show:1. At low temperature,dielectric constant ε(ε' ,ε'' ),dielectric loss tangent tgδis small at ω<104Hz or ω> Hz.2. When temperature is lower, ε' =ε, at low frequency ;ε'' =ε∞ at high frequency.3. When the relaxation of PAN molecule, polar group-CN is in step of ω,ε' ' ,tgδ reach maximum value . The area from ω=104 Hz to ω = 107 Hz is the glass transformation field of PAN.4. The conductor ratio y of PAN carbon fiber is mainly decided by electrons which do not band on nitrogen atoms and condensed cyclization degree (containing pyrdine cycles and their dispensation in PAN)and is affected by temperature,electric field strength. When T≥400℃,apparently increases j when E≥.Ec,apparently increases.