Studies On Synthesis And Characterization Of Water-borne Polyurethane Dispersions For Coating

With the further development of people's consciousness of environment in recent years, people pay more attention to environmental protection.An intense popular interest in "green revolution" was formed in coatings' circle to fit in with the need of this development,and main stress in coatings research is placed on developing environmental friendly coatings such as waterborne coatings,high solid coatings,radiation-curable coatings and powder coatings.Based on this tendency,the paper summarized the synthetic chemistry,synthetic method and its principle,and the researching situation of waterborne polyurethane-acrylate(WPUA) coatings. Then the paper put forward the guiding ideology of the research in this paper.Detailed and extensive studies on the syntheses and properties of WPUA coatings were conducted as follows:1.The polyurethane-acrylate was synthesized through the copolymerization between prepolymer of polyurethane and acrylic monomer.First the prepolymer of polyurethane was synthesized,then the prepolymer reacted with HEMA.After that a macro-monomer could be gotten.The macro-monomer was polymerized with acrylate,and the polyurethane-acrylate(PUA) was obtained.2.The synthetic methods of waterborne polyurethane and polyacrylate were investigated and several sorts of WPUA coatings were synthesized.The effects of many factors such as reaction temperature,sort of neutralizer,proportion of monomer,solid of emulsion on syntheses and properties of WPUA coatings were studied,and some useful results had been obtained simutaneously.3.The techniques of the structure and properties of the emulsion and film of WPUA coatings were characterized and studied.The relations between the rate of water adding,the content of-COOH and its degree of neutralization,the molecule weight of polyetherdiol, NCO/OH molar ratio and properties of WPUA coatings were investigated extensively as well.