共聚法引入甲基对聚苯胺结构及电导率的影响

Influence of Methyl Introduced by Copolymerization on Structure and Conductivity of Polyaniline

通过间甲基苯胺与苯胺在右旋樟脑磺酸水性介质中进行化学氧化共聚得到它们各自的均聚物及共聚物,在聚苯胺链段上引入甲基来改变产物的结构与电导率。用FT-IR、UV-Vis、XRD、SEM方法表征聚合物的分子链结构与微观形貌,用四探针法测定聚合物电导率。结果表明,所得聚合物为直径100nm左右的短纤维,聚苯胺分子链上甲基的引入削弱了苯环之间的π-π共轭,使FT-IR、UV-Vis光谱特征峰发生蓝移。在单体总浓度一定的条件下,可通过调节单体比例将聚合物的电导率控制在0.02～6.50S/m的范围内。XRD谱图分析表明,甲基还具有诱导聚苯胺分子链取向的作用,使聚苯胺链聚集态规整性提高。

Polyaniline, poly（m-toluidine） and their copolymers were synthesized through a chemical oxidative copolymerization in the medium of D-CSA（D-camphorsulfonic acid） aqueous solution. The molecular chain structure and conductivity of polyaniline was changed by importing methyl. FT-IR, UV-Vis, X-ray diffraction were used to characterize the molecular and aggregation structures of the polymers. The morphologies of the polymers were studied by SEM. Four-probe method was employed to investigate the conductive property of these polymers. The spectral character, structure, crystallinity, morphology and electrochemical activity of the polymers mentioned above were dis- cussed. The results show that polyaniline and relative copolymers appear as micro fibre with less 100 nm diameter. The introduction of methyl on the benzene ring weaken the rc-~ conjugate effect inside polyaniline molecular chain, which results in the blue shift of FT-IR, UV-Vis spectral characteristic peak. Conductivity of the polymers can be changed within a wide range from 0. 02 S/m to 6. 50 S/m by adjusting the monomer ratio. X-ray diffraction patterns show that the methyl connected in benzene ring can induce polyaniline molecular chain orientation, and improve the regularity of the aggregative state of polyaniline chain