Synthesis And Characteristic Of UV Curable Hyperbranched Polyurethane Acrylate For Coatings

Due to the rapid solidification, ultra violet curing technology has attracted more and more attention in the field of polyurethane coatings. Hyperbranched polymer has unique spherical structure, whose spherical appearance is connected to a large number of active groups, reducing the entwining between molecule chains, thus possessing low viscosity and high active. And acrylate material has good properties which provide a successful complement to polyurethane. The organic combination of ultra violet curing coating,hyperbranched polymer and acrylate materials reflects the advantages of all three.This paper synthesized excellent coatings with hyperbranched polyurethane oligomer as matrix resin, polymethyl acrylate synthesized by living polymerization as assistant resin,and other aids. It’s performance was researched basically.1. Hyperbranched polyurethane oligomer was synthesized using pentaerythritol triacrylate as the core, modified by 2-hydroxy-2-methylpropiophenone and hydroxyethyl acrylate. The structure of hyperbranched polyurethane acrylate was analyzed and characterized by Fourier Infrared Spectrometer, Nuclear Magnetic Resonance Spectrometer, Ultraviolet spectrometer and Thermogravimetric analyzer. The results showed that the prepolymer was consistent with the expected structure and had good thermal stability.2. Polymethyl acrylate has been synthesized with toluene as solvent,CuBr/CuBr2/tri(2-dimethylaminoethyl) amine as catalyst, 2,2’-azobis-bis[4-methoxy-2,4-dimethyl]pentanenitrile as radical initiator and ethyl 2-bromo-2-methylpropionate as atom transfer radical polymerization initiator. The kinetics of polymerization were studied by Gel Permeation Chromatography and Gas chromatograph. The results showed that the reaction was characterized by first order kinetics and has characteristics of living radical polymerization.3. This paper discussed and analyze the effect of hyperbranched photoinitiator on migration, yellowness, the effect of NCO/OH on water absorption, the effect of polymethyl acrylate content on flexibility, curing time, gloss, hardness and adhesion.4. Polyurethane acrylate coating were synthesized by traditional methods. Its prepolymer and films were analyzed on a series of characterization and performance. The results showed that hyperbranched coatings had better thermal stability, higher surface defense, better corrosion resistance and so on.