Synthesis Of Fluorine And Silicone Modified Acrylic Resin And Application In Waterborne Metal Coating

With the increasing awareness of environmental and the strict control of national policies,the traditional solvent based coating is gradually transforming to water based coating gradually.The performance of the product is improving gradually with the diversification of acrylic monomers and additives and the further improvement of the synthesis process.And the water based acrylic coating will develop toward of multi-function and high performance.The aim of this dissertation is to synthesize the water dispersed fluorosilicone modified acrylic coating by using the fluorosilicone monomer and acrylic monomer.The modified acrylic resin is physically doped or chemically grafted by preparing micro-nano composite structure SiO₂ particles to obtain a superhydrophobic coating with structural rigidity.Firstly,the water-dispersed fluorosilicone modified acrylic coating was prepared via the free radical polymerization.The effects of the amount of water-soluble monomer,the fluorine monomer and the silicon-containing monomer on the performance of hydrophobic coating was studied,and the weather resistance and physical properties of the coating were tested and analyzed.Secondly,based on the bionic“lotus leaf effect”,an ordered self-assembly strategy of micro-nano composite structure is proposed to construct SiO₂ micro-nano composite structure particles.The SiO₂ particles were chemically bonded with two kinds of SiO₂:one SiO₂ nanoparticles（10nm）with the amino-group and the other SiO₂ submicron particles（500nm）with the epoxy-group.Finally,through the chemical grafting between the micro-nano composite structure SiO₂ particles and the modified acrylic resin,the directional construction of the low surface energy micro-nano composite structure with rigid structure is realized.As a result,the superhydrophobic coating with structural rigidity,good wear resistance,excellent adhesion,and good mechanical propertie are prepared.The experimental results showed that the best experimental conditions for the preparation of the water dispersed fluorosilicone modified acrylic resin were as follows:the amount of water soluble monomer（MA）is 3 wt%,the amount of fluorine monomer（G06C）is 5 wt%,the amount of silicon monomer（DSi A）is 5 wt%,and the reaction temperature is 90℃.The hardness of the obtained resin coating is 3H,the impact strength is more than 50 cm,the cupping protrusion is more than 8.0 mm,the gloss（60°）is 106.3°,the water contact angle is97.2°,the test of butanone resistance is more than 100 times and weatherability is good.Also,the effect of reaction conditions on the size of the modified SiO₂ nanoparticles was researched,the best experimental conditions were as follows:the amount of TEOS is 3.8 wt%,the amount of catalyst is 2.0 wt%,the amount of water is 6.4 wt%,the reaction temperature is 90℃and the time of reaction is 6 hours.As a result,the average size of the organic modified SiO₂ nanoparticles is 10 nm,the particle size distribution is relatively uniform.When the mass ratio of acrylic resin and SiO₂ with micro-nano composite structure is 1:2,the contact angle of the coating by physical blend method is 150.6°,the superhydrophobic effect is achieved.Although the hydrophobic effect of the coating prepared by chemical modified method with the same mass ratio are slightly lower than those prepared by physical blend method,the result of friction test showed that its wear resistance is better,and the self-cleaning effect is excellent.A novel method to prepare waterborne fluorosilicone modified acrylic resin is proposed in this paper,which can achieve the superhydrophobic effect of the coating under the water-based condition,and also has strong wear resistance,adhesion,weather resistance and mechanical properties.It has a wide application prospect in high-end construction,rail transit,home furnishing,marine engineering and other fields.