Study On The Complex Of Polyaniline/Water-soluble Polymers

Polyaniline have received enough attention and have been widly applied in technology such as rechargeable batteries, electrochromism, electromagnetic interference shielding, especially in metal anticorrosion because of their low cost, excellent conductive performance, diverse structure, environmental stability, unique doped mechanism and can be easily synthesized. But polyaniline must be compounded with other ingredients in order to reach ideal effect of anticorrosion because of their bad performance of dissolution and conglutination. With the increasing awareness of environmental protection and the developing of anticorrosion coatings in the direction of environmental protection, energy saving, water-based paint become a important direction and focus of research on coatings. Waterborne epoxy coatings and water-based acrylic emulsion paint have good corrosion resistance, flexibility and adhesion, can dry fast and recoating time is short so that they have a broad application prospects in the field of anti-corrosion coatings. In this paper, the influence of different synthesis conditions on the performance of polyaniline are investigated. Meanwhile, the complex of polyaniline/water-soluble polymers are prepared with doped polyaniline and waterborne epoxy or water-based acrylic emulsion and the conductivity, mechanical properties, corrosion resistance of complex materials are studied.The doped polyaniline was synthesized by using tungstic acid peroxide as a homogeneous catalyst in the presence of hydrogen peroxide and hydrochloric acid or4-methylbenzenesulfonic acid(TSA). The residual hydrogen peroxide in the reaction system was decomposed by addition of KI after chemical polymerization. The filtration or azeotropic distillation of methylbenzene and water was used in the separation of the doped PANI. The product was obtained by the azeotropic distillation in good yield as compared with the filtration. The structural changes of the doped PANI were observed by FTIR and UV-vis. The electric conductivity of the doped PANI was measured by four-point terminal method. The electrical conductivity of the resulting doped PANI film is in the order of10-5S/cm.Polyaniline/water-based epoxy resin complex are prepared using more traditional preparation process. This is to say, polyaniline and waterborne epoxy resin emulsion are synthesized respectively and then mechanically blend them together according to appropriate proportions. In a stationary curing temperature, the amount of the curing agent on the mechanical properties of the composite are investigated and the experimental results show that the mechanical properties of the composite coating is best when XCT-802:aqueous epoxy=20:100. The influence of the added amount of polyaniline on the electrical conductivity, mechanical properties, hardness and adhesion of the polyaniline/aqueous epoxy resin composite coating are investigated. The test results show that, the added amount was20%,3%,20%and25%, the corresponding performance achieve the best. Use water-based acrylic emulsion with the solid content of30%and polyaniline to blend mechanically to prepare polyaniline/water-based acrylic emulsion complexes. When the amount of additive polyaniline is20%to25%, the hardness of the composites improve significantly and the amount of additive polyaniline is25%, the performance of adhesion to the substrate is best.