| Polyurethane dispersions had received considerable attention in the past decade due totheir merits in not easy to burn up and environmental protection and lower energyconsumption. But traditional polyurethane dispersions had some defects in a long dry time,low heat-resistance and water-resistance, etc, which result in a limited application scale. Anovel waterborne polyurethane-acrylate for aqueous dispersions (PUAs) based on4-(4-hydroxypheny)-2,3-phthalazin-1-one (DHPZ), polyethylene glycol (PEG), dimethylolpropionic acid (DMPA), 2,4-toluene dissocyanate (TDI) and 2-hydroxyethyl acrylate (HEA)is investigated. The product of the synthesize process was recorded by FTIR and the spectrahad been studied by following the disappearance of the isocyanate vibrational band found at2270cm-1. The expansion vibrate peak at 3300cm-1, the benzene peak at 1605～1591cm-1 andthe appearance of the peak at 812cm-1 also had been found and it can identified that thepolyurethane-acrylate dispersion had been made. The effects of the ratio of NCO and OH andthe content of hydrophilic group (DMPA) had been studied by the particle sizes. The resultsof the particle sizes revealed that when the ratio of NCO and OH is below 1.4 and the contentof DMPA was about 6%, the average particle size of the dispersions was about 200nm. Thedegree of neutralization had been studied, and the result showed that when the degree ofneutralization was 100%, the dispersion was not easy to deposit and the storage could keepthree month.The coating based on the resin mentioned above was made after some assistant agentwas added. And the UV-cured PUA films were formed under a UV high pressure mercurylamp and a part of them had been heated. The curing process is identified by the FTIRspectroscopy monitoring the changes of the IR band at 812 cm-1 assigned to the acrylatedouble bond vibrations. The effect of the curing time, the ratio of NCO and OH and the hardsegment on gel fraction had been studied. The result showed that the films reached a highergel fraction of 81% after casting under the UV lamp 30sec. When the ratio of NCO and OHwas 1.2, a better coating sample was obtained and the gel fraction is 87%. It was observedthat an increase in hard segment content decreased the content of gel fraction. The effect ofheat treatment on water swelling and mechanical performance had been studied. The resultshowed that the water-resistant had been greatly improved after heated treatment, the water swelling was below 1%. The mechanism properties of the membranes were well after curing.The pencil hardness was 5H and the adhesion power (grade 1), impact strength(50 cm). Theproperties were keeping after heated at 100℃for 30min.The thermogravimetirc analysis(TGA) had been studied because of the aim of the experiment. The weight loss of 5% wasabove 200℃which identified that the films had more resistant to heat. The highesttemperature of the 5% weight loss of the films was 219℃.
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