Preparation And Performance Study Of Waterborne Phosphate Ester Modified Acrylic Alkyd Resin Coatings For Steel Structures

Alkyd resins are widely used for the protection and decoration of large outdoor steel structures because of their flexibility,good wettability of the filler,easy availability of synthetic raw materials and simple processes.However,traditional alkyd resins still suffer from slow drying,low hardness,poor weatherability and the production of large amounts of volatile organic compounds when cured,which limit their development.Therefore,it is necessary to modify and waterborne alkyd resins by acrylic resins for extending the application range of alkyd resins.The main research content of this article is following.(1)Synthesis and performance study of waterborne alkyd resins.Waterborne alkyd resins were synthesized with linoleic acid,phthalic anhydride,trimethylolpropane and tri-mellitic anhydride,and the effects of oiliness,alcohol excess and hydrophilic monomer dosage(mass fraction)on the resin properties were investigated.The results show that when the oil content is 50%,the alcohol excess is 1.15 and the amount of hydrophilic monomer is 7%,the performance of the emulsion and the adhesive film is the best,the appearance of the emulsion is milky white with blue light,the water solubility is good,the drying time of the adhesive film is less than 24 h and the hardness is B.(2)Synthesis and performance study of waterborne acrylic modified alkyd resins.The effects of the addition of(meth)acrylate monomer(mass fraction),glass transition temperature and acrylic acid grafting(mass fraction)on the resin properties were investigated.The results show that when the addition of(meth)acrylate monomer is 83.33%,the glass transition temperature is 40℃ and the grafting amount of acrylic acid is 6%,the performance of the emulsion and adhesive film is the best,the storage stability of the emulsion is more than 6 months,which has a good water solubility,and the surface drying time of the adhesive film is 30 min,the hardness reaches H,the corrosion potential is-0.399 V,the corrosion current density is 6.21 × 10-6 mA·cm-2,which has good water and corrosion resistance.(3)Preparation and performance study of acrylic alkyd resin coatings modified with waterborne phosphate.The effect of the addition amount(mass fraction)of HEMAP on the properties of acrylic alkyd resins modified with waterborne phosphate was investigated.The results show that when the addition of HEMAP is 2%,the best performance of the adhesive film is achieved,with a corrosion potential of-0.318 V and a corrosion current density of 3.59×10-6 mA·cm-2,and the adhesive film has good water and corrosion resistance.The formulation optimized emulsions were formulated with face fillers and additives to form coatings,which were coated on tinplate sheets using the spraying method.The performance of the coatings was discuss and found to be superior to waterborne alkyd coatings through the modification of acrylic resins and phosphate esters.