Preparation And Properties Of Long-lasting Protective Composite Organosilicon Materials

Coating polymer resin coatings with high mechanical properties and low surface energy on the metal surface can reduce the surface fouling and corrosion of metal substrate.Such metal protection methods have the characteristics of high protection efficiency and simple operation.However,the existing resin materials which can achieve efficient antifouling and long-term anti-corrosion at the same time have the following shortcomings:Firstly,some materials use fluoropolymer components to reduce the surface tension of the coating so as to achieve excellent antifouling and anti-corrosion effects.However,fluorine-containing materials have obvious defects that are expensive and harmful to the environment.Secondly,the existing anti-fouling and anti-corrosion coatings need to add components containing biological activity to achieve the effect of anti-biological adhesion,and to improve the anti-permeability of resin matrix by adding graphene,boron nitride and other nanomaterials to obtain better barrier and anti-corrosion function.However,these technologies involve complex chemical modification to enhance the stability of functional filler materials in anti-corrosion coatings,which leads to high cost and complex preparation process of such technologies,thereby reducing the value of its industrial application.Third,the traditional epoxy resin,polyurethane and other mainstream metal protection materials have the problems of high brittleness and poor weather resistance,and because of its relatively high surface energy and poor surface antifouling effect,it is necessary to cooperate with toxic components to enhance its anti-biological adhesion function,which requires the use of a large number of toxic metal materials to produce risks and hazards that are difficult to ignore to the ecological environment.Silicone resin is a kind of composite material with many advantages,such as low surface energy,high thermal stability,high weather resistance and so on.It can realize efficient antifouling and anticorrosion on metal surface at the same time.It has great potential and prospect in the field of metal protection.However,the bonding force between the silicone resin and the substrate is relatively limited.The existing silicone metal protection technologies are mostly bonded to the metal surface by silanol polycondensation or hydrosilylation.This method has the disadvantages of harsh reaction conditions and low reaction efficiency.Based on the above problems,in this paper,a series of composite silicone protective coatings with high hydrophobicity,anti-fouling and anti-corrosion properties were prepared by copolymerization of silicone prepolymer(PDMS~V)and various acrylate monomers through high-efficiency free radical polymerization.The main research contents of this paper are as follows:(1)A composite silicone resin protective coating was prepared based on PDMS~Vmodification.The curing time of the resin coating is short,and the fastest drying time at room temperature is only a few seconds to several minutes,which is beneficial to the application of the resin coating on the surface of thermal sensitive substrates such as plastics.The composite coating has good transparency and hydrophobicity,the highest transparency is more than 90%,and the surface water droplet lag angle and sliding angle can be as low as 1°and 2°,respectively.AFM images show that the non-uniform distribution of PDMS components with high mobility in the composite coating can make the coating surface present typical micro-nano rough structure,which can effectively improve the hydrophobicity of the coating surface.The results of differential scanning calorimetry(DSC)and thermogravimetric analysis(TGA)of the coating samples show that the composite coating has good thermal stability.The surface properties of the coatings were tested by friction,bending and scratch treatment.The results show that the composite coating has excellent damage resistance.(2)In the study on the antifouling and anti-corrosion properties of the silicone composite resin,it was found that the resin coating had broad-spectrum antifouling applicability,and it could achieve surface self-cleaning effect on various substrates such as glass,metal,wood,cotton fabric and plastic.Moreover,different water and oil liquids such as water,hexadecane,glycerol,peanut oil,milk and coffee could slide on the surface without leaving traces,showing excellent antifouling properties.Moreover,the coating showed great potential in anti-biosorption and anti-corrosion in bacterial adsorption experiments and marine hanging plate experiments,which could effectively reduce the adhesion of organisms on the coating surface.The corrosion solution immersion test,salt spray test and electrochemical impedance test results show that the composite coating can achieve long-term corrosion protection on the metal surface.(3)The waterborne silicone composite resin emulsion with antifouling and anti-corrosion properties was further prepared to achieve the environmental friendliness of the composite resin.By investigating the effect of emulsifier system and organic silicon content on the properties of emulsion and composite resin film,the emulsifier system was determined to be sodium dodecyl benzene sulfonate(SDBS)and methyl glucoside sesquistearic acid ester(SS)with mass ratio of 1:2.The best emulsifier dosage is 2 wt%;the best organic silicon content is 9 wt%.Under the optimal conditions,the coating showed good hydrophobic properties,and the acid and alkali solution immersion test results showed that the waterborne resin coating had certain corrosion resistance.