Preparation And Modification Of Waterborne UV-curable Coatings Based On Epoxy Acrylate And Urethane Acrylate Prepolymer

Waterborne UV-curing coatings combined with the water-borne coatings and traditional uv-curable technology advantages, such as pollution-free, burning-free, no effect on human health. It has become the hotspot of coating industry and is oriented to green products of the 21 stcentury. But long curing time, poor water resistance and mechanical properties and low hardness exist in this kind of coating. Therefore, in this paper, waterborne epoxy acrylate and polyurethane-acrylate prepolymer as film substrates were synthesized to prepare waterborne uv-curing coating, and at the same time, films modified with different inorganic particles, and the structure and performance of the films were characterized. The concrete research content is as follows:1. Firstly, waterborne epoxy acrylate prepolymer as film substrates was synthesized and self-made benzyl triphenyl phosphorus chloride modified vermiculite(BTPC-VMT) as enhanced particle were used to prepare waterborne uv-curing coatings. The preparation technology of WEA was explored and the structure and properties of WEA and coatings were characterized. The results showed that: the appropriate reaction conditions of WEA were that the molar ratio of epoxy acrylate resin and methyl hexahydrophthalic anhydride was 2:1, catalyst content of 1% of DMBA, polymerization inhibitor content of 0.05~0.1 wt% of MEHQ, reaction temperature of 75 ℃-80 ℃, reaction time of 150-180 min. When the addition of BTPC-VMT ≤3.0wt%, BTPC-VMT can evenly dispersed in the composite films, the impact strength, pencil hardness, solvent resistance and thermal stability of composite films were improved significantly; the optimum addition of BTPC-VMT was 2.0wt%,The resulting composite films had the best comprehensive performance and were promising for a wide range of applications for surface protection on metal and wood.2. The waterborne polyurethane-acrylate(WPUA) and organosilicon modified polyurethane-acrylate(Wsi-PUA) oligomer as film substrates were synthesized by anionic self-emulsifying method, g-C3N4 as enhanced particle were used to preparewaterborne uv-curing coatings. The preparation technology of WPUA was explored and the structure and properties of oligomer and coatings were characterized. The results showed that: the appropriate reaction conditions of WPUA were that: catalyst content of 1.0% of DBTDL, polymerization retarder content of 0.05-0.1wt% of hydroquinone monomethyl ether, reaction temperature of 75℃-80℃, the first phase of the reaction time of 2.5-3h, the second phase of the reaction time of 2.5-3h.Compared with WPUA, the tensile strength and water resistance of films prepared by Wsi-PUA improved; When the addition of g-C3N4 ≤1.0wt%, with increasing volume fraction of filler, the hardness, tensile strength, gel content, water resistance and thermal stability of the composite films were significantly augmented; the optimum addition of g-C3N4 was 1.0wt%, The resulting composite films had the favorable comprehensive performance and were promising for a wide range of applications for surface protection on metal and wood.