Study On Synthesis And Properties Of Phosphate/Acrylate Modified Waterborne Alkyd Resin

With the continuous improvement of environmental regulations and increasing awareness of environmental protection, water-borne coatings have attracted great attentions in recent years. Waterborne alkyd resin is an environmentally friendly coating with low cost, whose development and application is of enormous economic and social benefits. This dissertation includes the synthesis of phosphate/acrylic modified water-borne alkyd resin and the application properties as coatings. The main achievements of this thesis are summarized as follows.Monoglyceride method was adopted to synthesize the water-borne alkyd resin. First, alcoholysis reaction was applied to improve the compatibility of different reactants. Then a new modified prepolymer was synthesized by the copolymerization of maleic anhydride, acrylic ester and phosphate ester, whose structure was characterized by FTIR,GPC and DSC. Using the anhydride groups in the prepolymer, we synthesized a waterborne acrylic modified alkyd resin by esterification. The advantage of this design is that the consumption of double bonds is avoided which is determined by iodometric method and FTIR.The influence of the resin variables in the synthesis of the waterborne alkyl resin on the performance of the modified resin was studied in detail. The synthetic formulation and process is optimized. By adjusting the structure of the acrylic monomer used in the synthesis of the prepolymer, the molecular weight and the glass transition of the prepolymer is improved, which results in the improvement on the hardness and resistance to hydrolysis of the coating film prepared by the final resin. In addition, a variety of cross-linkable groups have be introduced in the alkyd, which can react with the residual hydroxyl groups in the resin. The multiple cross-linked structure produced in these reactions further enhanced the drying rate and chemical resistance of the waterborne alkyd coatings.