Study On Preparation And Performance Of Two-Component Normal Temperature Curing Waterborne Epoxy Anti-Corrosion Coatings

Epoxy resin has a compact molecular structure and contains highly active groups such as hydroxyl,ether bond and epoxy group,which has excellent physical and chemical properties.Epoxy resin and curing agent can form polymer materials with a network structure,which are widely used in fields such as structural materials,corrosion-resistant materials,and electrical insulation materials.At present,bisphenol A type epoxy resin is the largest and most widely used among many resins,but this type of resin generally has high viscosity,most of which are solid or high viscosity liquids at room temperature.When used,diluents such as toluene,xylene,and butyl glycidyl ether need to be added.Therefore,solvent based epoxy resins are prone to pose hazards to the environment and human health during their application.Waterborne epoxy resin uses water as the dispersion medium,which contains less volatile organic compounds（VOCs）and has the advantage of green environmental protection.By modifying it,excellent performance waterborne epoxy anti-corrosion coatings can be prepared.Two-component waterborne epoxy coatings mainly use waterborne epoxy resin as the film-forming material,and form an excellent curing film through cross-linking reaction with the specific curing agent.This article explores two key components of two-component waterborne epoxy coatings,which two types of two-component waterborne epoxy anti-corrosion systems that can cure at normal temperature and have better performance were investigated.Two kinds of two-component waterborne epoxy anti-corrosion coatings were prepared in parallel by adding appropriate inorganic fillers and additives to the two systems,and the correlation between the coatings was systematically tested.The main research content is as follows:（1）A non-ionic self-emulsifying waterborne epoxy curing agent（CA₁）was synthesized using m-Xylylenediamine（MXDA）as the base amine and modified with epoxy resin E20 and polyethylene glycol（PEG）,which has excellent comprehensive performance,and can cure at normal temperature.The CA₁-E44 coating was prepared using CA₁ emulsified and solidified of E44.The synthesis experimental conditions were compared and explored.The synthesis experimental conditions were compared and explored.The performances of the CA₁ and CA₁-E44 were tested and characterized through methods such as Fourier transform infrared（FTIR）testing,viscosity testing,stability testing,scanning electron microscopy（SEM）testing,and mechanical properties testing.（2）Through ring-opening polymerization and free radical graft polymerization,a modified epoxy resin emulsion with better comprehensive performance was synthesized by introducing hydrophilic monomer and acrylate polymer chain into epoxy resin E20,and the coating was prepared by combining existing waterborne fatty amine curing agent（CA₂）in the laboratory.The effects of raw material dosage,initiator type,neutralizer type,reaction temperature and time on the performance of modified epoxy resin emulsion and coating were compared and explored.The properties of modified epoxy resin emulsion and coating were tested and characterized by FTIR,SEM,stability test,differential scanning calorimetry（DSC）and other methods.（3）Preparation of two-component waterborne epoxy anti-corrosion coatings:an appropriate amount of precipitated BaSO₄ was added to the CA₁-E44 system and CA₂-modified epoxy resin system selected in the above experiments,respectively,to prepare two types of two component waterborne epoxy anti-corrosion coatings that can cure at normal temperature.The effect of the amount of precipitated BaSO₄ on the coating performance was investigated.The results showed that the coating surface was smooth and uniform,with good mechanical properties,corrosion resistance,and aging resistance when precipitated BaSO₄ was used as a filler and 5 wt%and 10 wt%were respectively added to the CA₁-E44 system and the CA₂-modified epoxy resin system.