Preparation And Properties Of The Acrylic Emulsion And Polyurethane Emulsion

The acrylic emulsion resins are low thermoplastic, high glass-transition temperatures, brittle and poor flexility of the coating in low-temperature, self-crosslinking study of technology at room temperature was a major hot spot in the research. Water-based polyurethane has good flexibility, incombustibility, corrosion resistance, weatherability, good adhesive force, etc, but because of the poor water resistance, solvent resistance, its application is limited. Its modification is necessary. In research, DAAM were used in self-crosslinking acrylic emulsion. Nano-silica and aqueous acrylic emulsion are opted as Modifiers to modify water-borne polyurethane. The main contents of the full text were as follows:1. The self-crosslinking acrylic emulsion was prepared, using DAAM as functional monomer, Adhesion, water resistance, hardness, solvent resistance has been significantly improved, water-resistance reached unchanged in water for 12 days, solvent resistance reached 14.8%, the hardness can be to 3H.2. The waterborne polyurethane emulsion modified by nano-silica was synthesized, using IPDI, PPG-2000 and nano-silica particles as raw materials for graft polymerization. The silica-PU particles were graft polymerized through a chemical bonding, so that nano-silica was dispersed in the polyurethane emulsion. Through measurement of water absorption test, solvent resistance, hardness and gel content, results, the results showed that the water-resistance reached 9.9%, solvent-resistance reached 15.1%, the hardness can be to 2H and gel content reached 79.4%. But the reaction conditions were not easy to control. When the amount of nano-silica was 0.3%, the reaction volume of slagging was as much as 10%, the stability of poor response.3. The PUA emulsion was synthesized in acrylic acid esters using DMPA, DAAM as functional monomer. The problem was successful solved,such as the high VOC content, Complex process and energy waste, caused by using acetone as the solvent.Through means of FT-IR, TEM and measurement of water absorption test, solvent resistance, hardness and gel content, we had studied the structure and properties of the PUA emulsion and coating. The results showed that the hardness of the PUA emulsion coating reached 3H, the gel content could reach 84.3% and water resistance, solvent resistance has been markedly improved.