| Polyaniline (PAn) is one of the most important conducting polymers because of its simple synthesis methods, particular doping mechanism, excellent environmental stability, as well as wide application. At present polyaniline has become one of the hottest focuses in conductive polymer area. With small molecular inorganic acid doping polyaniline has a higher conductivity, but its solubility and the stability are worse, limit its practical advancement. The macromolecular sulfonic acid has higher boiling point, both including the polar groups and the non-polar groups, its stability also surpasses the small molecular inorganic acid, therefore, using the macromolecular sulfonic acid to dope polyaniline can enhance the conductivity and the application, which has the certain practical significance.As a result of magnetic field can change molecular orientation and control rate of chemical reaction and change product structure and enhance its performance, therefore, study on the synthesis and properties of doped polyaniline in magnetic field has become one of the hottest focuses. But, to our knowledge, no systematic study with respect to the properties of doped polyaniline by sulfonic acid in magnetic field has yet been published.In this article the technology of high performance polyaniline under the circumstances of microemulsion in magnetic field were synthesized. Some technologic conditions were researched: such as the category and dosage of doped acid the category and dosage of emulsifier agent, the category and dosage of oxidant and reaction time; then, the best technologic conditions were confirmed through the orthogonal experiment. The polyaniline's conductivity, microstructure, anticorrosion, crystallization, thermal stability, particle size and others properties were analyzed and characterized by modern testing methods, such as IR, XRD, TGA, UV, and so on. Finally, through the comparison of synthesized products without magnetic field, the optimal or the improved collocations were worked out. According to such collocations that the effect of doped polyaniline in magnetic field.In comparison with out magnetic field, the results indicated that the change of characteristic peak values of polyaniline at their infrared spectrum is not obvious, the X-ray diffraction peaks of polyaniline becomes very intense, which showed the microstructure of polyaniline was not influenced in magnetic field, but the orientation and regularity of polyaniline is obviously improved in magnetic field.Under magnetic field, based on the data from the experiment in lab condition, the results indicate that the time of the polymerization and the dosage of doped agent were reduced and the conductivity of polyaniline is enhanced in the presence of magnetic filed. The polymerization time decreased from 3 h to 1 h; the concentration of doped acid(CSSA)decreased from 0.4 mol·L-1 to 0.3 mol·L-1; the mole ratio of emulsifier and aniline monomer (nSDBS/nAn) decreased from 0.6 to 0.45; the mole ratio of oxidant and aniline monomer (nAPS/nAn) decreased from 0.8 to 0.6; the conductivity of polyaniline increased from 1.65×10-1S·cm-1 to 10.54×10-1S·cm-1 in magnetic field. The corrosition potential of polyaniline has increased by 31%, the thermal decomposition temperature has increased by 6%. Compared with the present polyaniline without magnetic field, the polyaniline synthesized by this improved technology has evident advantages in certain properties, such as conductivity, particle size, thermal stability, anticorrosion, uniform arrangenent, synthetical cost and son on, therefore, possessing bright prospects in marketing development and application.
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