有机/无机酸复合掺杂导电聚苯胺的合成及性能研究

采用化学氧化聚合法以苯胺为单体,过硫酸胺为氧化剂,在有机/无机混合酸的水溶液中合成导电聚苯胺.考察了有机/无机混合酸对聚苯胺性能的影响,并通过四探针、差热分析、红外光谱及拉曼光谱研究聚苯胺掺杂前后结构的变化.结果表明,当聚合温度为20℃、磺基水杨酸和硫酸的摩尔浓度比为0.25:1时,掺杂态聚苯胺电导率和溶解度达到最大值;其中电导率可达13.5 S·cm~(-1),在氮甲基吡咯烷酮(NMP)中溶解度可达85%.差热分析表明,有机/无机酸复合掺杂聚苯胺热稳定性较单一酸掺杂聚苯胺热稳定性有很大的提高;红外光谱和拉曼光谱表明;掺杂后聚苯胺具有导电性是因为其分子链上电荷离域形成了共轭结构.

Synthesis and Properties of Conducting Polyaniline Doped with Compound Organic/Inorganic Acids

Polyaniline (PANI) were synthesized in compound organic/inorganic acids aqueous solution by chemical oxidization polymerization with aniline as monomer and ammonium persulfate as oxidant. The properties of the synthesized polyaniline were studied and characterized by four-probe, thermogravimetric analysis (DSC/TGA), FT-IR and Raman spectrometric analysis. The results show that, when the polymerization temperature is 20℃ and the mol concentration ratio of sulfosalicylic acid (SSA) to sulfuric acid (H_2SO_4) is 0.25:1, both the conductivity and the solubility (in NMP) of the synthesized doped polyaniline reach their maximum and they are 13.5 S·cm~(-1) and 85%, respectively. The DSC/TGA show that the synthesized polyaniline doped with compound organic/inorganic acids has better thermal stability than that of polyaniline doped with single acid. It was found that the good conductivity of doped polyaniline may be attributed to the dislocation of charge and the forming conjugation of molecular chain in the polyaniline after it is doped with protonic acid.