Study On Synthesis Of Hyperbranched Waterborne Polyurethane Acrylate Dispersion

The UV curable waterborne polyurethane acrylate(WPUA) has the advantages of energy saving, environmental friendly, efficient, economical, enabling. Because of the ammonia ester bond in molecular chain, WPUA has multiple hydrogen bonds, which make the coating has good impact resistance and adhesion etc.. However, WPUA is lack of cross-linking structure,and weak in heat resistance, hardness etc..In this paper, hyperbranched waterborne polyurethane acrylate(HBPUA) was prepared.Hydrophilic chain extender, soft segment types and other factors on the effect of HBPUA was studied. Also, the synthesis process was adjusted to optimize synthetic route. In addition, for improving the properties of HBPUA, series of WPUA was prepared, and blending with HBPUA. The effect of the type and amount of WPUA on the blends was studied.The optimum condition of HBPUA synthesis: IPDI/HEA synthesis in 75℃, about 90 min,with the hydroxy anisole as polymerization inhibitor; Hyperbranched polyester(HBP) was one-time added into the reaction system in 75℃. When used PPG1000 as material, the dosage of DMPA was7.75 wt.%, R was 2.2, the grafting degree is 100%, study can obtain the good properties of emulsion and coating.When used PPG1000 as material, the dosage of DMPA was 4~6wt.%, R was 1.2~1.6,WPUA had good emulsion and film properties. The different kinds and dosage of WPUA was blending with HBPUA, which made HBPUA has the storage stability, chemicals resistance etc..