A Water-soluble UV Curable Epoxy Pre-Ploymer Prepartionand Studing

The birth and development of UV-curing technology provide exciting opportunitiesand expansive potential application for the coating industry. With the development ofscience and technology, people pay more attention to UV waterborne coating because of itssuperior performance, environment friendly and low cost.The waterborne UV-curable coating was prepared from waterborne UV-curableoligomer, photoinitiators, polymerization inhibitor, water and other additives. Thewaterborne UV-curable oligomer is the most important component, which decides theproperty of curing film such as hardness, flexibility, adhension, etc.In this study, the preparation of the waterborne UV-curable oligomer was researchedthroughout the following two aspects:An UV-curable epoxy prepolymer (EA) containing more hydrophilic groups wassynthesized with DMPA, acrylic acid (AA) and epoxy resin (E-51). The anhydride modifiedepoxy prepolymer (M-EA) was prepared from the reaction of EA with maleic anhydride(MA), and neutralized with alkali. The reaction conditions such as reaction temperature,catalyst content and the amount of DMPA were investigated. The results show that theoptimum reaction conditions of EA were as follows: DMPA:AA in the mole ratio was3:7;reaction temperature was100℃; BDMA content was1.0wt.%, reacting time was210min.The optimum reaction temperature of M-EA was90℃, reacting for150min. And finallypre-polymer’s water-solubility reached16.2wt.%; The film curing time is37s, and thehardness is2H, the comprehensive performance is better.An UV-curable epoxy prepolymer (EA) was prepared by E-51and AA. The anhydridemodified epoxy prepolymer (TM-EA) was prepared from the reaction of EA with MA andTMA, and neutralized with alkali. The reaction conditions such as reaction temperature,catalyst content and the amount of TMA were investigated. The results show that theoptimum reaction conditions of EA were as follows: reaction temperature was100℃;reaction time was240min, BDMAcontent was1.0wt.%. The optimum reaction temperatureof TM-EAwas85℃, When the amount of anhydride (n(MA):n(TMA)=8:2) is90wt.%, andfinally pre-polymer’s water-solubility reached20.16wt.%; the film curing time is41s, andthe hardness is2H, the comprehensive performance is better.