Study On The Synthesis Of Carboxylate/Sulfonate UV-curing Waterborne Polyurethanes

UV-WPU had a fast curing speed,high hardness,high gloss,excellent water/solvent resistance,and so on.Could be widely used in metal anti-corrosion,leather finishing agents,wood coatings and fiber surface treatment agents.There were a wide variety of synthetic raw materials and a variety of synthetic process routes.The development potential in the future water-based coating industry was good.In this study,a photo-activated macromonomer,UVPE,was prepared from a dimer acid ring-opened GMA and using it as raw material to synthesize new UV-WPU process.It was first necessary to determine the UVPE synthesis process,including the control of the reaction temperature and the acid endpoint.After that,the influence of the kind and amount of raw materials on the performance of UVPE was studied.Using homemade UVPE,using polyester as the soft segment;IPDI as the hard segment;DMPA and BY-3306 D as the hydrophilic chain extenders of carboxylic acid and sulfonate type;and TMP or CHDM as the small molecule chain extender to successfully prepared UV-WPU.To made it looking good and had excellent performance after UV-curing,the synthesis process was first determined,including the determination of the charging sequence,the reaction temperature at each stage,and the control of the reaction endpoint.After that,the influence of the kind and amount of raw materials on the state of the product and the properties of the paint film after UV curing were studied.These effects included the hardness,gloss,and water/solvent resistance of the paint film.The improvement of the film performance by UV-curing was studied,including the amount of2959 and the influence of the UV curing time.Through experiments,it had been found that the type and amount of polyester were the key factors affecting the appearance and alcohol resistance of the product.Therefore,the most suitable polyester diol T5651 was determined through continuous adjustment and screening.When T5651 was a soft segment,and IPDI was a hard segment,the UVPE content was 11%-17%,the DMPA content was 3%,the BY-3306 D content was 5%,and the CHDM content was 6.5%.The prepared UV-WPU product was resistant to storage,had afine particle size,had excellent paint film performance after light curing,and had a solid content of more than 40%.The synthesized product was added with a photoinitiator 2959 with a solid content of 4%,and the control of the illumination time was best after the UV curing for about 30 s.The FTIR was used to analyze the photocuring pre/post film with the corresponding groups,which was by the expected structure.The TGA/DSC was used to verify that the UV-WPU resin film had good thermal stability;TEM observed the resin particles.The size was uniform and evenly distributed.In this topic,a suitable amount of related additives was added to the synthesized UV-WPU resin,and a UV-WPU water-based white paint was successfully prepared,which could be used to produce a metal finish or a primer.When the amount of BYK028 was0.5%;the amount of RM2020 was 1.2%;the amount of TEGO-270 was 0.3%;the amount of TEGO-740 W was 0.7%;and the amount of 2959 was 6% of the solid content of the resin.The prepared water-based white paint had strong hiding power after the photocuring and had no unpleasant phenomenon such as missed bottom.Through the performance test,the hardness reached 2H,the water/solvent resistance was excellent,and the adhesion was good.The prepared white paint meets the metal finish and Primer use standard.