Studies Of Preparation And Properties Of Vinyl Acrylic Polyurethane Hydrophobic Anticorrosive Coatings

Fluorinated acrylic polyurethane coatings have excellent corrosion resistance, long-lasting durability and good hydrophobicity as well. It is widely used in automobiles, home appliances, petrochemical and many other industries and It also presents a rapid development trend in the world. In this work, the fluorinated acrylic resin were synthesised by the solution polymerization using fluorinated acrylate monomer and Acrylic monomers; and making the obtained acrylic resin and polyurethane curing agent crosslinked to prepare coatings which have a good performance in anti-corrosion and hydrophobicity. Also, the corrosion diffusion process of water in organic film in salt solution was studied by EIS.Methacrylate monomers and G04 were used as raw materials to prepare fluorine-containing acrylic resin. The optimized parameters are as follows: Mass ratio between xylene and butyl acetate is 1:1.4. And solvent and benzoyl peroxide (BPO) as initiator is added 0.55%; the insulation time is 175min after an hour reaction of polymerization under 125℃. The obtained fluorine resin has a Excellent overall performance. Fluorine resin's viscosity is about 30pa.s and its solid is over 66%. Fluoride content of Fluorinated resin film is about 8%. The max contact angle between film surface and water is about 103°.The preparation technology of fluorocarbon varnish is as follows: The weight ratio of fluorinated resin and curing agent is 6:1. The max contact angle between fluorocarbon lacquer coating and water is 111.2°. The preparation technology of hydrophobic anti-corrosion coating is as follows: Defoamer addition is 0.15%, film-forming agent addition is 16%, and leveling agent addition is 0.3%. The prepared hydrophobic coating has corrosion resistance in 10% hydrochloric acid more than 120h. In 3% saline it has corrosion resistance up to 300h, and the same long anti-corrosion in 10% alkali soltuon. Paint viscosity is 40 pa.s and solid is 60%.Adhesion level is 1 and its impact strength is 90kg.cm. The corrosion current density of coating is 2.64×10-8 A/cm2. The actual glass transition temperature of polymer is between 50℃and 54℃temperature. This result has a difference of 5℃or less with the designed glass transition temperature of the fluorinated polymer, which is in line with the expected design goals.The Resistance of hydrophobic coatings immersed in 3.5% saline for 24h was increased and the changing tredns of its capacitance is opposite and after 24h, the resistance is down to 104 ohm. Beiseds, the higher the temperature of salt water immersion, the bigger the diffusion coefficient in the coating. The diffusion activation energy of salt water in the coating is 70.52kJ/mol.