Research On The Synthesis Method Of Pua And Its Coating Performance

The coatings obtained from methyl methacrylate(MMA) activemonomer reacting with urethane acrylate(PUA) resin by free radicalpolymerization solidification with initiating system has excellentphysical-mechanical properties, especially the property of weatherresistance. In this paper, the synthesis conditions of PUA resin wasstudied and the optimal synthesis conditions was obtained byoptimization of the synthesis's technology and monomer's selection.For the synthesis of PUAresin, the selection and pretreatment of rawmaterials, the selection of synthesis's methods and the control ofsynthesis's conditions were researched in detail. The PUA prepolymerwith good flexibility and yellowing resistance property was prepared byusing the IPDI, polyester diol and HEA by the method of masspolymerization including two step reaction and made a summary fromconsidering catalyzer, reaction temperature etc. which affect synthesis'sprocesses and product's properties. Subsequently, the optimaltechnological conditions applied in synthesizing PUA were obtained: first,polyalcohol reacts with IPDI to form prepolymer with NCO functionalgroup at 50℃; second, adding HEA at constant rate until the reaction'sterminal at 60℃using thedibutyltin dilaurate as catalyzer with the totalcontent of 0.08%.Many properties of the coating solidification film, such as hardness,adhesive force, solidification rate, flexibility etc., were studied. The resultshowed that: 1) the main factors which affect coatings film hardness andflexibility were chain's length and molecular weight of long chaindihydricalcohol used in synthesizing PUA resin and glass transitiontemperature of active monomer; 2) the main factors which affectsolidification rate were initiating agent content , temperature andhumidity.