Study On The Synthesis And Performance Of Water-Borne Acrylic Modified Alkyd Resin Coating

Alkyd resin coatings are widely used for many advantages, such as low cost, good adhesion, gloss, full of color, good wetting properties and good application property. But traditional alkyd resin coatings are solvent-based, with the organic solvent as thinner, which adversely affect the environment and human body. With the increased awareness of environmental protection, countries began to limit VOC (Volatile Organic Compound) and HAPS (Hazardous Air Pollutants). The Kyoto Protocol Clearly stated the VOC emission limits in industrial materials. Therefore, research on the environment-friendly water-borne alkyd resin coatings can reduce solvent usage amount and pollution, but also bring great economic and social benefits.This paper, water-borne acrylic modified alkyd resin coatings were synthesized form the reaction between monoglycerides prepared from vegetable oil and acrylic copolymer prepared form maleic anhydride (MA) and acrylic monomer. Factors affecting the film properties were analyzed to improve the over-all properties of the coating. The central contents are as follows: 1, Monoglycerides were synthesized form the alcholysis reaction between vegetable oil and trimethylolpropane (TMP) with sodium hydroxide (NaOH) as catalyst under 230℃, improved the efficiency of alcholysis reaction. Acrylic copolymer was prepared by radical copolymerization of MA and acrylic monomers with benzoyl peroxide (BPO) as initiator, the yield reached to 97.69%.2, The synthesis conditions were investigated. By analyzing the process conditions, the optimum reaction conditions were determined. Water-borne acrylic modified alkyd resin was synthesized with 14-20% xylene as solvent which control the reaction temperature at 180℃for about 2.5 hours. Made the acid value fell to 50-70 mg KOH·g-1, neutralized with triethylamine (TEA) at a level of 65-75% can obtained clear and transparent emulsion with good stability.3, Discussed a variety of factors on the emulsion stability, drying rate and film properties. Clear and transparent emulsion with small particle size and good stability were prepared after neutralizing with TEA at a level of 65-75%, when the acid value fell to 50-70 mg KOH·g-1. The dry rate of the film can be increased by selecting an appropriate drying agent, or choosing appropriate baking temperature.4, Compared the film properties of different water-borne acrylic modified alkyd resin coating prepared form different acrylic monomer and vegetable oil. Confirmed that the film scratch hardness, acid and alkali resistance of the coating prepared form dehydration of castor oil (DCO) is much better than that form soybean oil (SO), and the over-all properties of the coating prepared form i-BMA copolymer is better than that form n-BMA copolymer.5, i-BMA modified water-borne alkyd resin coatings prepared form DCO had good emulsion stability. The scratch hardness, impact resistance, water, acid, alkali resistance and other over-all properties of the film were improved.