Synthesis And Characterization Of Uv-initiated Waterborne Polyurethane Acrylate

In recent years, with people increasingly attach importance to environmental protection and environmental regulations have been gradually strengthened, the emission of volatile organic compounds (VOC) from traditional solvent-based paints has been limited in the world. Therefore, the development of low pollution and even non-polluting paint become one of the main direction of coating developed.UV-initiated waterborne coatings combine the advantages of waterborne technology and UV technology. Owing to fast curing speed, environmental friendliness, energy saving and excellent film properties, UV response waterborne coatings has been developing rapidly in the last20years and become a new generation of green chemicalproducts.The main content of this thesis is to synthesize and modify UV-initiated waterborne polyurethane with KH550, epoxy resin, acrylate, and get environment friendly paint with good film properties.(1) A series of ultraviolet curable waterborne polyurethane acrylate resins (UV-WPUA) had been synthesized from isophorone diisocyanate (IPDI), poly (ethylene oxide) glycol (PEG), dimethylol propionic acid (DMPA), pentatry thritol triacrylate (PETA). The effects of the different conditions on resin water-soluble and performance of the film was investigated. The results showed that when the content of DMPA, double bond, photoinitiator and n(-NCO)/n(-HO) were6-8%,0.873-1.558mmol/g and3%(mass ratio) and1.3-1.4respectively, the UV-WPUA exhibited good properties.(2) We used3-aminpropyltriethoxysilane (APTES) to open the epoxy ring of bisphenol-A-based epoxy resin (APTES-E51) and incorporated it into the chains of polyurethane to synthesize a series of multiple cross-linking UV-curable waterborne polyurethane dispersions (UV-PUDs). The average particle size increased with increasing the APTES-E51content and the stability of the UV-PUD storage became poor when the content of APTES-E51was10.0%. After modification with APTES-E51, the water resistance, thermal stability and tensile strength of films were all raised. We can obtain good storage stability, satisfied water resistance, high thermal stability and tensile strength when the APTES-E51content is9.1%.(3) A series of polyurethane (PU)/fluorine-containing polyacrylate (PA) latex interpenetrating networks (LIPNs) were synthesized in two stages. Firstly PU dispersion was synthesized by self-emulsification polymerization. Then the PU/fluorine-containing PA LIPNs using PU dispersion as a seed were prepared by ultraviolet (UV)-initiated soap free emulsion polymerization. Compared to the corresponding thermal-initiated polymerization, UV-initiated polymerization could be accomplished at a higher speed and a lower temperature. The incorporation of fluorine-containing groups markedly improved the water resistance and the thermal stability of the LIPN film. We could obtain satisfied water resistance, high thermal stability and mechanical property when the PU/fluorine-containing PA weight ratio reached1/1.