酚醛树脂热解炭的电磁屏蔽性能

Electromagnetic Interference Shielding Effectiveness of Phenolic Resin Pyrolytic Carbon

以热固性酚醛树脂（PF2123）为原料,经固化、成型和热解制备了块体碳材料,通过XRD、TG-DSC、激光拉曼光谱、SEM等对热解产物进行了表征,考察了热解温度和Fe Cl3催化剂对热解产物的微观形貌、有序化程度和X波段电磁屏蔽性能的影响。结果表明：热解的最终产物为无定形碳,1000℃热解时的残炭率为55%;随着热解温度的升高,热解炭的有序化程度提高,电导率增大,电磁屏蔽效能（EMI SE）先增大后减小,900℃热解时的电磁屏蔽效能最高达28.2 d B;添加占酚醛树脂质量0.5%的Fe Cl3催化剂在1000℃进行催化热解时,酚醛树脂热解炭内原位生成了大量多壁碳纳米管,形成了导电网络,提高了其电磁屏蔽性能;加入质量分数0.5%Fe Cl3催化剂对于1500℃热解试样的电磁屏蔽性能改善作用更为明显,特别是在低频段。

Bulk carbon materials were prepared via solidification, molding and pyrolysis of thermosetting phenolic resin（PF2123）. XRD, TG-DSC, laser Raman spectroscopy, SEM and so on techniques were used to characterize the pyrolytic products. The effects of pyrolytic temperature and Fe Cl3 catalyst on the micro morphology, ordering degree and electromagnetic interference shielding effectiveness（EMI SE） in X-band of phenolic resin pyrolytic products were investigated. The results showed that the finally pyrolytic products were amorphous carbon. The residual amount of carbon after pyrolysis of phenolic resin at 1000 ℃ was 55%. With the increase of pyrolytic temperature, the ordering degree and conductivity of pyrolytic products increased, while the electromagnetic interference shielding effectiveness（EMI SE） first increased and then decreased. The sample obtained by pyrolysis of PF2123 at 900 ℃ exhibited the largest electromagnetic interference shielding effectiveness of 28.2 d B. When PF2123 was pyrolyzed at 1000 ℃ in the presence of a catalytic amount of 0.5% Fe Cl3（based on the mass of phenolic resin）, there were large amounts of in-situ multi-walled carbon nanotubes formation in the pyrolytic carbon, which formed conductive networks. This led to an improvement of electromagnetic interference shielding effectiveness of sample. Moreover, the addition of 0.5% Fe Cl3 could significantly improve the electromagnetic interference shielding effectiveness of pyrolytic product at 1500 ℃, wherein that in low frequency was more obvious.