Research On Systhesis And Performance Of UV/Moisture Dual Curing Resins

Light-curing coatings have received widespread commercial attentions arose from their competitive properties of fast curing,energy-saving,and environmental protective.However,UV curing cannot be completely achieved on complex three-dimensional surfaces,compound filling systems and thick films substrates,which limits the application in coating fields.Therefore,it is of great significance and practical value to develop a resin available for both ultraviolet radiation curing and dark reaction curing.In this work,γ-glycidylpropyltrimethoxysilane(KH-560),hexahydro-4-methylphalic anhydride(MTHPA),and three kinds of acrylic resin(hydroxyethyl acrylate(HEA),pentaerythritol triacrylate(PETA),and Pentaerythritol pentaacrylate(DPHPA))was used as raw materials for the synthesis of three functional dual-curing basic resins.Subsequently,photoinitiator type and content were explored by measuring the double-bond conversion rates to valuate curing efficiencies.Then the moisture curing rates were studied by analyzing the surface-drying time,and moisture curing rates were further improved by replenishing silane coupling agents and moisture curing catalysts.Infrared spectroscopy(FT-IR)and Hydrogen nuclear magnetic resonance spectroscopy(1H-NMR)were used for structure characterization,scratch adhesion test and thermogravimetric analysis(TGA),etc.were used to investigate the coating properties of three acrylic basic dual-curing resins.Characterization results indicate that the UV curing rate maximizes when the photoinitiator content is 5 wt% and the moisture curing speed maximizes when 3-Aminopropyltriethoxysilane(KH-550)content reaches 8 wt%.The optical catalyst content is 0.6 wt%.W100 exhibits the highest adhesive strength but poor thermal stability.Subsequently,the formulation and technological parameter of the composite dual-curing resin was determined.Firstly,the water contact angle and scratch adhesion test on various substrates were measured.The effect of volume shrinkage on adhesion strength was explored and adhesion promoter EM-39 was added to further improve the combining efficiency.Finally,the influences of the acrylic resin ratio on the stability of the composite dual-curing resin are compared.Results show that the composite dual-curing resin exhibits dual-curing abilities and when the content of EM-39 is 0.06～0.08 wt%,the adhesion levels of reach 1 grade entirely among five composite dual-curing resins.W120 is assigned as the matrix resin due to the optimal general performance.At last,we put forward three methods to improve the heat resistance of the resin substrate: increasing the crosslinking density,copolymerization with heat-resistant resins,blending with an inorganic filler,respectively.TGA analysis and scratch adhesion test were performed to measure the effect of deposition temperature.Moreover,water contact angle,light transmittance,haze,pencil hardness were discussed synergistically to confirm the appropriate modification route.Consequently,introduce of strong chemical bonds in the molecular chain and inorganic filler blending significantly improved the heat resistance of the resin.