化学学报 ›› 2008, Vol. 66 ›› Issue (5): 571-575. 上一篇    下一篇

研究论文

对甲苯磺酸掺杂聚吡咯的合成、表征及其对金属镁的防腐蚀性能研究

李倩倩,黄健涵,刘素琴,关鲁雄,黄可龙   

  1. (中南大学化学化工学院 长沙 410083)
  • 投稿日期:2007-07-10 修回日期:2007-09-04 发布日期:2008-03-14
  • 通讯作者: 黄可龙

Synthesis and Characterization of Polypyrrole Doped by p-Tolyl Sulfonic Acid and Its Anticorrosion Property for Magnesium

LI Qian-Qian, HUANG Jian-Han, LIU Su-Qin, GUAN Lu-Xiong, HUANG Ke-Long*   

  1. (College of Chemistry and Chemical Engineering, Central South University, Changsha 410083)
  • Received:2007-07-10 Revised:2007-09-04 Published:2008-03-14
  • Contact: HUANG Ke-Long

以对甲苯磺酸为掺杂剂, 三氯化铁为氧化剂, 化学氧化吡咯制备了对甲苯磺酸掺杂聚吡咯. 考察了掺杂剂与氧化剂的用量对掺杂聚吡咯电导率的影响, 得到了高电导率聚吡咯的优化条件, 用UV, IR和SEM对其结构和形貌进行了表征. 结果表明, n(对甲苯磺酸)∶n(吡咯)∶n(三氯化铁)=0.75∶1∶0.5时, 合成的聚吡咯的形貌规则, 电导率达42.7 S•cm-1. 以聚吡咯为功能成分, 环氧树脂为成膜物质, 得到一种功能膜, 旋涂于金属镁表面, 采用极化曲线和开路电位考察了含有聚吡咯的膜层对金属镁的防腐蚀性能. 结果表明, 含有聚吡咯的膜层对金属镁有很好的防腐蚀性能, 腐蚀电流为0.0981 A, 腐蚀电位为-0.88 V, 在膜层与金属镁之间形成了一层钝化膜.

关键词: 对甲苯磺酸, 聚吡咯, 掺杂, 电导率, 防腐蚀

Polypyrrole doped by p-tolyl sulfonic acid was chemically synthesized from pyrrole using p- tolyl sulfonic acid as a doping agent and ferric chloride as an oxidant. The effect of dosage of the doping agent and the oxidant on the conductivity of doped polypyrrole was investigated, and the optimized conditions were obtained. The molecular structure of the polypyrrole was characterized by UV and IR spectra, and its morphology was studied by SEM. The results indicated that the polypyrrole was regular, and its conductivity reached 42.7 S•cm-1, when the ratio of n(p-tolyl sulfonic acid)∶n(pyrrole)∶n(ferric chloride)=0.75∶1∶0.5. A film containing the polypyrrole was prepared on magnesium surface, and its anticorrosion property was investigated by potentiodynamic polarization curves and open circuit potential. It was found that the polypyrrole showed an excellent anticorrosion property for magnesium, the corrosion current and voltage were measured to be 0.0981 A and -0.88 V, respectively, and a passivation layer was formed between the film and magnesium surface.

Key words: p-tolyl sulfonic acid, polypyrrole, doping, conductivity, anticorrosion