Preparation Of Polyaniline-graphene Oxide Composite And Its Application In Anti-corrosion Coatings

In the field of anti-corrosion coatings,conductive polyaniline has attracted widespread attention because of its advantages of environmental friendliness,easy preparation,chemical stability,and the formation of a passivation layer on the metal surface.Graphene based two-dimensional materials make coatings good corrosion resistance and mechanical properties due to the large specific surface area and high Young’s modulus.In this paper,polyaniline-graphene oxide composite materials were successfully prepared and used in self-healing coatings,water-based epoxy coatings,and water-based acrylic coatings,respectively.The prepared supramolecular elastomer poly(urea-urethane)-polyaniline-graphene oxide(PUU-PAGO)self-healing material has good mechanical properties,room temperature self-healing ability and potential anti-corrosion properties.With polyaniline-graphene oxide composite as additives,the physical properties and anti-corrosion performance of waterborne epoxy coatings and waterborne acrylic coatings have been significantly improved.This paper explores the effect of adding different amounts of graphene oxide(GO)on the impedance value of poly(urea-urethane)-graphene oxide(PUU-GO).It is found that when the amount of GO added is 2 wt%,the coating The electrochemical impedance value is the largest,and when the addition amount of PAGO is 2 wt%,the performance is better than PUU-GO.It can be seen that the introduction of polyaniline has played a certain role in the improvement of the coating impedance value.Through the tensile test,it is found that the addition of 2 wt% PAGO significantly improves the tensile strength of the material,which is 3.35 times that of the material without PAGO.By cutting the spline and stretching at different healing times,it was found that with the increase of the healing time,the tensile strength and elongation at break of the spline also increased significantly.After 1 minute of healing,the reconnected joints It can be bent at will,and the strength is enough to withstand a certain tensile force;after 48 hours of healing,the tensile strength of the sample reached about 4.17 MPa,and the elongation at break was about 723.0 %,respectively reaching 88.35 % and 84.97 % when not sheared.After adding PANI,GO and PAGO to the waterborne epoxy coating,the adhesion is improved from grade 2 to grade 1.The film hardness level of the waterborne epoxy coating and PANI-waterborne epoxy coating is 4H,GO-waterborne epoxy coating and PAGO-The film hardness of the water-based epoxy coating is 5H,and the film hardness level is significantly improved.The impact strength of GO-water-based epoxy coating and PAGO-water-based epoxy coating is 50 cm and above.The impact strength of waterborne epoxy coatings and PANI-waterborne epoxy coatings is only 40 cm.This article also discusses the principle of corrosion at the scratches of the paint film.Through the salt spray corrosion experiment,it was found that the composite material additive after grafting polyaniline on the surface of graphene oxide has a significant improvement in the corrosion resistance of the water-based epoxy coating,which is superior to the single polyaniline or graphene oxide additive,and at the same time improves the water-based Anti-corrosion performance of oxygen paint.Through the scratched salt spray corrosion experiment,it was found that compared with water-based epoxy coatings,the corrosion of GO-water-based epoxy coatings has improved significantly after 480 hours of corrosion.The overall anti-corrosion effect of PAGO-water-based epoxy coating has been further improved compared to GO-water-based epoxy coating.The adhesion of water-based epoxy acrylic coatings and coatings with PANI,GO,PAGO are all grade 1,the film hardness level of water-based acrylic coatings and PANI-water-based acrylic coatings is 2H,while the film hardness of GO-water-based acrylic paint and PAGO-water-based acrylic paint is 3H,and the film hardness level is significantly improved.The impact strength of GO-waterborne acrylic paint and PAGO-waterborne acrylic paint is 50 cm and above,while the impact strength of waterborne acrylic paint and PANI-waterborne acrylic paint is only 40 cm.Through the salt spray corrosion experiment,it was found that the anticorrosion performance of the composite material additive after grafting polyaniline on the surface of graphene oxide to waterborne acrylic paint was significantly better than that of single polyaniline or graphene oxide additive,which improved the anticorrosive performance of waterborne acrylic paint.Through the scratched salt spray corrosion test,after corrosion for 480 hours,GO-water-based epoxy acrylic coating is better than water-based epoxy-acrylic coating.PAGO-water-based epoxy acrylic coating effectively prevents corrosion.