PAN/PMMA共混制备纳米碳纤维的结构与性能

以N,N-二甲基甲酰胺(DMF)为溶剂,以聚丙烯腈(PAN)为碳前驱体,聚甲基丙烯酸甲酯(PMMA)为热裂解聚合物,制备PAN/PMMA溶液共混体系,经湿法纺丝及碳化工艺制备了纳米碳纤维(CNFs);讨论了影响CNFs形态、尺寸的主要因素,通过傅里叶变换红外光谱、X射线衍射、拉曼光谱和电导率测试等对CNFs进行了表征。结果表明:相对分子质量为8.0×10~4的PAN与PMMA以质量比30/70进行共混纺丝和碳化,可以得到CNFs;增加原丝的拉伸倍数有利于减小CNFs的直径,当拉伸倍数提高到6时,CNFs直径为50～150nm;碳化温度为800℃时,CNFs出现石墨相结构;提高碳化温度有利于CNFs石墨化结构的形成与电导率的提高。

Structure and properties of PAN/PMMA carbon nanofiber

The blend system of polyacrylonitrile/polymethyl methacrylate(PAN/PMMA) solution was prepared using N,N-dimethylfbrmamide (DMF) as solvent,PAN as precursor and PMMA as pyrolytic polymer,and was spun into carbon nonafiber (CNFs) via wet spinning process and carbonization process.The dominating factors affecting the morphology and dimension of CNFs were discussed.The obtained CNFs were characterized by Fourier transform spectroscopy,X-ray diffraction,Raman spectroscopy and electrical conductivity detection.The results showed that CNFs can be prepared by blend spinning PAN with the relative molecular mass of 8.0×10~4 and PMMA at the mass ratio of 30/70 prior to carbonization.The draw ratio growth of the precursor was in favor of declining the CNFs diameter.The diameter of CNFs was 50-150 run as the draw ratio was increased to 6. The graphite phase structure of CNFs formed as the carbonization temperature was 800℃.The increase of carbonization temperature was beneficial to the formation of graphite phase structure and the conductivity elevation of CNFs.