Synthesis And Properties Of UV-heat Hybrid Cured Epoxy Resin-polyurethane Acrylate Nanocomposites Coating

In order increasing properties of polyurethane acrylate (PUA) coating, in this paper,methylacryloylpropyl-trimethoxysilane (MAPTMS) were added in the system. At the sametime, the methylacryloylpropyl polyhedral oligomeric silsesquioxanes (MAP-POSS) andnano-SiO2were synthesized, they were all used to modify polyurethane-acrylate coating.The diphenyliodonium salt was synthesizedas as photoinitiator, making the systemradical-cationic curing and UV-heat curing. The curing raction, dynamic mechanical andthermal degradation of coating were investigated. The main work as follow:1. The dual curing reaction and kinetics of UV and thermal was investigated byUV-radiation and DSC, and the influence of the methylacryloylpropyl-trimethoxysilane(MAPTMS) content on the properties of coating was determined by DMA and other physicalmethods. The results show that, When the content of KH-570reach12wt%, the Tgis thehighest, which is8.2℃higher than the before; The thermal curing reaction has morecompletely reaction than the light curing. In the thermal curing, the reaction could bedescribed by autocatalytic esták-Berggre model and kinetic equations of curing reactionwere obtained. The average activation energy Eais70.55kJ/mol.2. The UV-heat curing with the methylacryloylpropyl polyhedral oligomericsils-esquioxanes (MAP-POSS) were modified epoxy resin (ER)/polyurethane acrylate (PUA)coating was prepared. DPI·PF6was used as photoinitiator, the curing raction, dynamicmechanical and thermal degradation of coating were investigated. The results showed that thesystem had better UV curing properties, but the rigidity of material could be futhur improvedby UV-heat curing. As the same time, the UV-heat curing could increase the glass transitiontemperature (Tg), which the Tgwas about50℃higher. When the content of the MAP-POSSreached12wt%, the highest Tgof the systen was98.5℃. The degradation activation energiesEawas calculated by Friedman method, as could be seen, the Easignificantly improved withthe increase of β in the different content of the MAP-POSS.3. The UV-heat curing nano-SiO2modified epoxy resin (ER)/polyurethane acrylate(PUA) coating was prepared. With the Friedman method and the Flynn-Wall-Ozawa method, we could see, The degradation activation energies Eaimproved with the increase of thecontent of the nano-SiO2, about30kJ/mol. When the content of the nano-SiO2reached4wt%,the was the higtest. The reaction order n also improved with the increase of the content of thenano-SiO2,the Eaand the n in the UV-heat curing both higher than the UV curing. Moreover,the UV curing and UV-heat curing could make a good film-forming, the hardness and impactstrength increased with the adding of the nano-SiO2.