Synthesis, Curing Kinetics And Properties Of UV-Cured Polyurethane-Acrylate Nanocomposites Coatings

In order to obtain UV-curable polyurethane-acrylate (PUA) coating with more excellentperformance, in this paper, the methylacryloylpropyl polyhedral oligomeric silsesquioxanes(MAP-POSS), polyhedral oligomeric silsesquioxane containing vinyl group (V-POSS) andnano-SiO2were synthesized, and were used to modify polyurethane-acrylate coating. Therelationships of cure kinetics and thermal properties of system were investigated. The mainwork as follow:(1) Syntheais of UV-curable epoxy-acrylate/polyurethane-acrylate coating modified withV-POSS, cured process and kinetics were investigated by FTIR, DSC, and dynamicmechanical analysis (DMA). The results show that this coating has a good UV-curableproperty, and the two components have very good compatibility and can co-cure in freeradical polymerization. The curing reaction can be described by a two-parameter autocatalytic esták-Berggren (S-B) model. The modified UV-curable coating has good adhesive strengthfor steel and hardness. The mechanical loss peak temperature Tpis highest when the contentof V-POSS is60%, which is increased by5.2oC than the pure system.(2) UV-curable bi-component coating of glycidyl methacrylate (GMA)/PUA modifiedwith MAP-POSS were prepared. The dynamic mechanical properties and thermal behavior ofnano-hybrid coating (GMA/PUA/MAP-POSS) were characterized with DMA,thermogravimetric analysis (TGA) and the FTIR. The results indicate that the threecomponents have well compatibility and can co-cure in UV-radialization by a free radicalpolymerization. The addition of MAP-POSS enhanced the thermal properties, the mechanicalloss peak temperature Tpis85.5oC when the amount of MAP-POSS is10wt%, which isincreased by12.6oC than the pure system. When the content of MAP-POSS is20wt%,thermal decomposition temperature in the initial stages was increased by7oC than that of thepure GMA/PUA.(3) UV-curable coating of GMA/PUA/nano-SiO2was prepared and UV-cured process andkinetics were investigated by FTIR, DSC, and DMA. The results indicate that the threecomponents have well compatibility. The curing reaction can be described by a two-parameterautocatalytic esták-Berggren (S-B) model. When the content of nano-SiO2is10%, themechanical loss peak temperature Tpis highest, which is increased by7.3oC than the puresystem.