Preparation And Properties Of Water Borne Anti-corrosive Coating Resins For Coatings

Metal corrosion can cause huge economic losses and potential safety hazards.It is of great practical significance to study effective metal corrosion protection methods.There are many methods of metal anticorrosion,of which paint coating corrosion is the most economical,practical and effective method.The traditional anti-corrosion coating resins are mostly solvent-based.During production and use,volatile organic compounds(VOCs)are discharged,causing environmental pollution and damage to the constructors and users.With the increasing awareness of environmental protection and environmental protection requirements of people,reducing the content of VOC has become an urgent problem to be solved.Among the many solutions,water-based traditional solvent-based coatings is the most economical and practical method.Water-based coatings use water as a dispersion medium and can achieve basic zero-VOC emissions,thus not affecting the environment.Based on the performance requirements for water-based corrosion-resistant resins for coatings and combined with the performance characteristics of epoxy resins and polyurethane resins,the chemical structure of the target molecule was designed,and the synthetic design of the polyurethane-modified epoxy resin was designed accordingly.Water-based resin preparation process were optimized,and obtained a good stability of the self-emulsifying emulsion:the carboxylate and ether bond for the hydrophilic group and the polyurethane segements with the isophorone diisocyanate(IPDI)were introduced to the epoxy resin,and the epoxy resin chain segments were used fou curing and film formation.By analyzing the properties of emulsion stability,film flexibility,hardness,adhesion,thermal stability,water resistance,and resistance to acid and alkali salts,comprehensive consideration of performances leads to the best synthesis process plan:1)The DMBA with the molar ratio of IPDI 0.5 is added to a four-mouth bottle with a condenser tube,a thermometer,and a stirrer.The water bath is heated to 80°C,with the protection of nitrogen,and the catalyst DY-20 is added.2)Add PEG4000 and E-44.The molar ratio between PEG4000 and IPDI is 0.2,E-44 hydroxyl and IPDI molar ratio of 0.3.Heated to 85℃,the reaction 2.5h;3)Triethylamine is added at 100%neutralization to get salt;4)Cool down to 60°C,plus deionized water and high-speed stirring for emulsification;5)Cool to room temperature and discharge.The waterborne resin emulsion was characterized and tested by infrared spectroscopy(IR),thermogravimetric analyzer(TGA),transmission electron microscope(TEM),and Zata potential analyzer.The results show that:1)The synthesis scheme successfully introduces the desired groups in the molecular chain;2)The synthetic process scheme can obtain an aqueous resin system with an average particle size of 102.82 nm and excellent stability;3)The dispersed phase is formed into a regular Spherical;4)The modified resin has good thermal stability(5%weight loss rate corresponds to a temperature of 282℃).The prepared aqueous resin is cured by using TETA,GCA02,and amino resin as the curing agent,and the polarization curve of the film is analyzed,as well as flexibility,water resistance,thermal stability,acid and alkali salts,salt spray resistance and other performance analysis.And getting the best curing process:According to W(waterborne resin emulsion):W(triethylamine)is 8:1 uniform mixing,140℃ insulation 40min,180℃ for 20min to obtain a film forming material.The thermal stability of the film forming material is good,the corresponding weight loss rates of 5%and 10%are respectively 335°C and 360°C;hardness:4H;flexibility:2mm;excellent corrosion resistance:acid resistance 18d,alkali resistance 20d Salt-tolerance 18d,acid-resistant salt spray 240h.All of the above properties indicate that the above schemes for synthesizing waterborne resins have great potential for large-scale application.