Preparation And Application Of Novel Antiglare Waterborne Polyurethane

When strong light hits a surface of glass or polymer,light will be reflected specularly to form a glare.Generally,glare can be reduced by promoting the roughness of the surface.However,the suppression of unwanted reflections can simultaneously sacrifice the clarity,contrast,and resolution of the transmitted image.In this research,we made use of the excellent properties of waterborne polyurethane（WPU）and adjusted the content of hydrophilic chain extenders to fabricate an antiglare coating with high transmittance and good diffusing performance.Considering the high cost and poor water resistance of WPU,polyurethane-acrylate hybrid emulsion（WPUA）was prepared by adding methyl methacrylate（MMA）.The effects of antiglare performance with different experimental formulars were discussed.Furthermore,stability,thermal performance,mechanical properties and medium resistance of WPU-And WPUA were investigated.Specific conclusions are as follows:（1）WPU-Antiglare resin was prepared by polytetrahydrofuran glycol（PTMG）,isophorone diisocyanate（IPDI）,dihydroxy methyl propionic acid（DMPA）as reaction monomers,2-[（2-aminoethyl）amino]ethyl sulfonic acid sodium（A95）and hydrazine hydrate as chain extender.The prereaction was taken at 60℃for 1.0 h,then at 80℃for2.0 h,neutralize at 50℃for 15 min,and emulsified under 35℃for 30 min.The chemical structure of the prepolymer and WPU films were characterized by FTIR,and thermal decomposition properties of WPU films were analyzed by TG.The surface topography of WPU-Anti-glare coating indicated that nano-spheres were formed by SEM.These nano-spheres makes coating equipped with low gloss and high light transmission properties.The effects of antiglare performance and water resistance property of different DMPA and A95 contents were studied,the desired antiglare coatings were achieved under the optimized condition(R(n _NCO/n_OH)=1.9,w_DMPA=2.6-3.0%,w_A95=48-58%).However,the water resistance was poor and the water absorption was up to 60%.（2）Preparation of antiglare waterborne polyurethane-acrylate core-shell resin was studied.The successful synthesis of the WPUA was proved by the FTIR spectra,and core-shell latexes with polyacrylate as core and polyurethane as shell were confired by TEM images.Effects of R value,DMPA content,ratio of HEA/NCO and MMA content on surface topography and antiglare performance were discussed.It was indicated that,with the increasing R value,w _DMPA,ratio of HEA/NCO and w_MMA,gloss and light transmittance of WPUA series showed different tendency.When R was 1.8,w_DMPA was2.6%,HEA/NCO was 1-1.5 and w_MMA was 30-40%,rugged surfaces with nano-spheres of 200nm were formed,obtaining the gloss of 32.2 and light transmittance of 95.1%,and the emulsions were stable.（3）Compared the WPUA and WPU-Antiglare coatings,and analyzed the difference in stability,thermal performance,mechanical properties and medium resistance.The results suggested that the core-shell WPUA achieved excellent properties,such as good stability,thermostability,adhesion,hardness due to the good compatibility between two polymer systems and expecially overcame the poor water resistance.But to some extent,tensile strength and elongation at break decreased.