| The discovery of conducting polymer opens up a new field for the investigation and application of organic polymer. As a kind of new functional materials, PAn has become one of the hottest focuses in the conductive polymer area due to its simple synthesis method, particular doping mechanism, high electrical conductivity, good environmental stability and peculiar electrical, optical and magnetic properties. However its commercial applications are limited because of its poor processability and intractable nature, and its powder are infusible and insoluble in most solventsThe magnetic field can influence the chemical reaction containing radicals and can induce orientation of most organic polymer molecules due to the magnetic susceptibility anisotropy. The existence of magnetic field can greatly increase ordered and regularly of polyaniline chain, and improve the conductivity, and solubility of PAn.In this work, the effects of magnetic field on the properties and structure of re-doping of PAn were discussed. We also study the effects of magnetic field on conductivity of PAn powder and anticorrosive competence of its complex film.The body of the thesis is divided into 2 sections:①Effects of magnetic field on the properties and structures of re-doping of PAn. The effects of the category of doped agents, magnetic intensity, concentration of doped agents, re-doping time and temperature on re-doping PAn were discussed. And the modern analysis techniques, such as four-probe, laser granularity analytical instrument, electrochemistry workstation, thermogravimetric analysis (TGA), Fourier transform infrared spectroscopy (FI-IR), UV-Vis and X-ray diffraction (XRD) were used to the systematic studies of the effects of magnetic field on the structures and properties of re-doping PAn.The results show that the optimal conditions of re-doping PAn are as follows: doped acid is sulfasolicylic acid (SSA), magnetic intensity is 0.4T, concentration of doped agents is 1mol/L, the temperature of re-doping is 25℃and the time of re-doping is 6h.The experimental results show that the conductivity, solubility, particle size, anticorrosive competence, thermostability and other properties of PAn has been obviously improved in magnetic field, due to the effect of the cooperative effect of doped acid and magnetic field. In compared with 0.4T and without magnetic field that the conductivity was increased from 0.51S/cm to 3.4S/cm; the solubility in xylene was also increased from 12% to 23%; the temperature of thermal decomposition was improved from 484℃to 520℃; And laser granularity displays that about 90% the particles of PAn between 0.01~0.1μm; corrosion potential of complex film were improved 60mv. The experiment proved that magnetic field has some effect on structures of PAn in compared with without magnetic field, but in the range of 0.2~0.6T, has small effect on FI-IR and UV-Vis of re-doping PAn. Form XRD we can see that the PAn have a high degree of crystallinity in magnetic field, due to chains are formed more regularly and rigid, which results in a more compact structure.②Effects of magnetic field on the properties of PAn powder and PAn/epoxy complex film. In the range of 0~0.6T, the conductivity of PAn takes on toothed type increase, the larger magnetic field intensity the more obvious its growth trend. With the prolong of time, the conductivity will ultimately reach equilibrium; effect of magnetic field on complex film, the results show that the conductivity of complex film increases by increasing content of PAn, magnetic field action can make content of PAn reduce in complex film; when the content of PAn is ensured, the corrosion potential increase with increasing magnetic field intensity, and anticorrosive competence of complex film is also enhanced.
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