Study On Preparation And Properties Of Low-temperature Curing Polyethersulfone Coatings

Nowadays,metal corrosion is an unavoidable topic in the era when metal is widely used.Metal corrosion brings huge loss to the national economy,and it is easy to cause safety hazards,endangering people's safety..An anti-corrosive coating is one of the most widely used methods to prevent metal corrosion at present.Its anti-corrosive effect is good,cost performance is high,and operation is simple.Anti-corrosive coatings are usually made of common polymer resin,such as epoxy resin,acrylic resin,alkyd resin,etc.With the development of science and technology,the types of anti-corrosive coatings are becoming more and more abundant,and the choice of film-forming materials is not only limited to common materials.In recent years,more and more people in the field of coatings have turned their attention to special engineering plastic.The coatings prepared with polyethersulfone(PES)as the film-forming matter and polytetrafluoroethylene(PTFE)as the filler,not only possess excellent corrosion protection and mechanical properties,but also exhibit non-adhesion and hydrophobic properties.But PES is a kind of thermoplastic resin with high processing temperature,in general,PES/PTFE coatings need to be treated at high temperature(350-450?).However,the high temperature processing step has undoubtedly brought the deficiencies,such as energy waste,inconvenience in operation,cost increase,difficulty in equipment transformation and so on,which greatly limits application of the coatings.Therefore,it is of practical significance to reduce PES/PTFE curing temperature while maintaining or even improving properties for its application and promotion.In this paper,a series of low-temperature curing PES/PTFE coatings were prepared by introducing epoxy resin and appropriate curing agent as low-temperature crosslinking agent,designing the formula,and optimizing the preparation and coating technologies.First of all,the effect of curing temperature and curing time on the properties of the coatings was studied,and the optimal curing condition of PES/PTFE coatings(170?/ 2 h)was determined.Secondly,a series of coatings(44-X)with different crosslinking agent contents were prepared,and the influence of the amount of crosslinking agent on the coatings performance was investigated.The results showed that the addition of crosslinking agent greatly improved the anti-corrosion performance of the coatings.The addition of crosslinking agent had reduced the obvious defects inside the coatings,and the crosslinking structure of the crosslinking agent itself also acted as a barrier.These all had improved the shielding performance of the coatings and better prevent the infiltration of corrosive media.The anti-corrosion performance of 44-6 coatings was the best,and the comprehensive performance of 44-2 coatings was the best.In order to further improve the shielding effect of the coating and thus improve the performance of the coatings,graphene(graphene)or modified graphene(m-graphene)with lamellar structure was introduced into the 44-2 coatings to prepare a series of low-temperature curing PES/PTFE+graphene coatings(SFg C or SFmg C),and the influence of the amount of graphene on the performance of coatings was investigated.The test results showed that the anti-corrosion performance of the coatings was improved after the incorporation of graphene,among which the formulas with the best performance were SFg3 C and SFmg1 C.In addition,polyaniline(PAN)with excellent corrosion resistance was considered as fillers to be added to the coatings to improve the performance of coatings.At the same time,considering that PAN more contact with the metal substrate is conducive to give full play to its corrosion resistance,a low-temperature curing PES/PAN prime coating was formed by introducing PAN to replace PTFE of the low-temperature curing PES/PTFE coatings.In combination with a low-temperature curing PES/PTFE surface coating with better hydrophobicity(the formulation with the optimal amount of crosslinking agent),a series of low-temperature curing "PES/PAN prime coating +PES/PTFE surface coating" double-layer coating(SF-PC)was prepared,and the influence of the amount of graphene on the performance of coatings was investigated.Results showed that the anti-corrosion performance of the double-layer coatings was improved as compared to 44-2 coatings,and the optimum formula was SF-P2C.