The Synthesis Of A Novel UV-curable Prepolymer And Its Modification By Nano-SiO₂

Firstly, CHDMGE was synthesized with CHDM and ECH as raw materials, boron trifluoride ether complex was used as the catalyst and sodium hydroxide as the closing ring agent for the ring formation. The effects of catalyst amount, reaction temperature and the ratio of the raw materials on the yield and the epoxy value were studied, which showed that the optimal conditions were the ratio of boron trifluoride ether complex0.4wt%, n(ECH):(CHDM)=2.4:1.0, n(NaOH):n(CHDM)=2.2:1.0, the temperature of cyclical reaction was30℃.Secondly, a novel UV-curable prepolymer CHDMGEA was synthesized with CHDMGE and AA as raw material. Triphenyl phosphine was used as catalyst and4-methoxyphenol as polymerization retarder. The reaction time, the reaction temperature and the reactant ratio were studied, which showed that the best synthetic reaction conditions were the reaction temperature90-110℃, ratio of triphenyl phosphine0.90%, ratio of4-methoxyphenol0.20%, n(CHDMGE):n(AA)=1.00:2.20. The UV-curable coating was synthesized with the photosensitive prepolymer and photoinitiator. The test results showed that the performance of the coating was good.The modification of UV-curable coating by nano-SiO2was also studied. Nano-SiO2was treated by surfactant and coupling agent and filled into the UV-curable coating. Viscosity measurement and SEM observation showed that the nano-SiO2was well dispersed in the coating after modification. The hardness and tensile properties of the coating were measured and the results indicated that the hardness of the coating increased greatly after filling into nano-SiO2, and the tensile properties of the coating were also increased.