The Synthesis And Property Study Of A Novel UV-curable Prepolymer

Bisphenol-A epoxy acrylate is widely used as prepolymer with its high curing rate, high hardness of curing film, high gloss, thermal stability and excellent corrosion resistance, however, the current synthesis method of bisphenol-A epoxy acrylate is taking addition reaction of the raw material all at once that reaction temperature was105℃. The shortcoming of the current synthesis is unevenly of relative molecular weight distribution, high viscosity of resin, a less convenient and needing quite more reactive diluent during the mixture of coatings. Thus, the current synthesis will result in increased costs, on the other hand, the technology will become complex.Diethylene glycol diglycidyl ether is a kind of low viscosity epoxy compound which can lower the viscosity of the system, and improves the physical properties of resin when it was added to bisphenol-A epoxy acrylate. As a result, the thesis is put forward that a new kind of photosensitive prepolymers was synthesized with epoxy resin and Diethylene glycol. The details are as follows:A new kind of photosensitive prepolymers was synthesized with E-51/JX-023mixture and acrylic acid(AA) as raw materials with triphenylphosphine as the catalyst, and with4-methoxy phenol as the inhibitor. This thesis studied the effects of reaction temperature, the dosage of catalyst and inhibitor. Experimental results showed that the best reaction temperature was105℃, the best mass fraction of the catalyst and the inhibitor was0.80wt%and0.3wt%. When the substrates were mixed on the scale of2.5:1, the viscosity of the system was very low. So the UV-curing coating was prepared with adding photoinitiator to the new kind of photosensitive prepolymers, the UV-cured film has good properties.Furthermore, Nano-SiO2which was treated by surface modification with cetyl trimethyl ammonium bromide and coupling agent with KH-570and was filled into the new kind of photosensitive prepolymers, and adding photoinitiator to make of nanocomposite coatings, and investigated the dispersion of nano-SiO2in the resin by microscope. The results showed that the dispersion of nano-SiO2which was modified was good. And hardness and physical properties of its cured film was investigated, the results showed that the addition of nano-SiO2can enhance the hardness.