酚醛树脂热解炭的电磁屏蔽性能研究

Research on Electromagnetic Interference Shielding Effectiveness of Phenolic Resin Pyrolytic Carbon

摘要:

以热固性酚醛树脂为原料，经固化、成型、热解制备块体碳材料，通过X射线衍射、综合热分析、激光拉曼光谱、扫描电子显微镜等对酚醛树脂热解产物进行了表征，研究了热解温度和FeCl3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：酚醛树脂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，酚醛树脂热解炭的有序化程度提高，电导率增大，电磁屏蔽效能先增大后减小，900℃热解时的电磁屏蔽效能最高达28.2dB；加入0.5wt%FeCl3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，形成导电网络，提高了其电磁屏蔽性能；0.5wt%FeCl3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。

Abstract:

The bulk carbon materials were prepared via solidification, molding and pyrolysis using thermosetting phenolic resin as raw materials. The effects of pyrolysis temperature and FeCl3 catalyst on micro morphology, ordering degree and electromagnetic interference shielding effectiveness (EMI SE) in X-band of phenolic resin pyrolytic products were investigated through X-ray diffraction, TG-DSC, laser Raman spectroscopy and scanning electron microscopy. The results show that the final pyrolytic products of phenolic resin were amorphous carbon. The TG-DSC results indicate that the carbon yield of the phenolic resin pyrolyzing at 1000℃ was 55%. The ordering degree and the conductivity of phenolic resin pyrolytic products increased with pyrolysis temperature rising, and the EMI SE first increased then decreased. The EMI SE of sample pyrolyzing at 900℃ was 28.2dB. Large amounts of in-situ multi-walled carbon nanotubes grew and formed the conductive network in the phenolic resin pyrolyzing at 1000℃ with 0.5wt% FeCl3. These led to a high EMI SE. The EMI SE of phenolic resin significantly increased pyrolyzing at 1500℃ with 0.5wt% FeCl3, especially in low frequency.