A Research On Waterborne Acrylic Resin Coatings Resistant To Chloride Ion Corrosion

Chloride ion corrosion is a serious hidden danger for the industrial production and human life because of its universal existence and high harmfulness. The traditional way of preventing chloride ion corrosion is protective coating, but there are disadvantages such as environmental unfriendly, poor thermal stability, poor mechanical properties and so on. Therefore, the development of an efficient and environmental friendly anticorrosive coating is of very important significance.Using aqueous solution containing chloride ion, the corrosion behavior of different chloride ion concentration, temperature, time, pressure was studied. The weightlessness method was used to measure the corrosion rate, and XRD, EDS analysis was used to study corrosion products. Results showed that:with the increase of chloride ion concentration (mass fraction from 1% to 3%), and temperature (30? to 80?) and pressure (1 MPa to 6 Mpa), the corrosion rate increased from 0.2265 g/(m2·h) to 2.3353 g/(m2·h), but decreased with time (1d to 7d). The corrosion current density showed the same and the order of the factors that influencing the corrosion rate of chloride ion was followed by pressure, concentration, temperature and time. The corrosion type of P110 steel under the above conditions was pitting, and chloride ion corrosion product was mainly FeCxOy and chloride ion played a catalytic role in the corrosion process.The acrylic resin, high etherified melamine formaldehyde resin and graphene were used to prepare graphene modified acrylic resin coating. The five factors and four levels orthogonal experiment was used to select the optimum formulation of coating. The volatile organic compounds and formaldehyde (HCHO and TVOC) detection, chemical immersion test, FTIR, TGA and electrochemical experiments were used to test the coating environmental performance, chemical corrosion performance, functional stability, thermal property and electrochemical properties. The results showed that:when the mass fraction of acrylic resin was 50%, etherified melamine formaldehyde resin was 10%, graphene was 0.1%, ZnO and Zn3(PO4)2 had the mass ratio of 1:1, the mass fraction of 0.1%, and other filler 14.9%, water 15%, additives (ethylene glycol, pH regulator, dispersant, emulsifier, defoaming agent, reactive diluent, film-forming agent) 2.5%, and the paint had no agglomeration, no crack, the adhesion was to level 1, the pencil hardness 6H, the impact strength 47cm, the mass of the wear 0.0004g, the wear and hardness and other mechanical properties increased 1.5 times than the acrylic resin coating without graphene modification. The release amount of TVOC and HCHO was 1/5 and 1/40 of the national limit after curing. The coating still had good surfacial stability and functional stability in acid, alkali and chloride solution. The heat performance improved by more than 63% than conventional modified acrylic resin coating. Self corrosion potential increased with the concentration of chloride ion (mass concentration from 1%to 3%), and temperature (30? to 70?) and time (1 d to 5 d) from -0.684 V to -0.3986 V, and coating self corrosion current density showed the same with the aforementioned self corrosion potential. The property improvement of the paint and coating may be related to the polar bonds in modified graphene.