Study On UV-Curable Nano-Composite Coatings By Sol-Gel Method

UV-curable nano-hybrid coatings were prepared by sol-gel method in the research,and the coatings were modified by adding silane coupling agent, changing the structure of resin and adjusting the technic of sol-gel. We hope to get the nano-composite material whose performance is very well.Hybrid coatings with EA/SiO₂ and PUA/SiO₂ structure were synthesized,and the coatings' mechanical performance of the film were investigated. The effect of silane coupling agent dosages, catalyzer , pH value on the sol-gel process and the curing technic were studied.The silicon dioxide sizes of coatings were under 100nm and increased with the content of TEOS observed by TEM. It manifested that the nano silicon dioxide prepared by sol-gel technology can disperse well after it was modified by silane coupling agent.The results indicated that When the content of silane coupling agent is between 0.25—0.5, the coatings exhibit good mechanical performance such as pencilhardness, impact strenghth, especially the abrasion of the film for PUA/SiO₂ system is increased by 7 times. Moreover stability of the coatings was improved remarkably by adding silane coupling agent.It was shown that incorporation nano-particles of SiO₂ into PUA coating could much enhance hardness, impact strength, and wear resistance of the curing film. But there is an optimum content of SiO₂, beyond which these mechanic performance would reduce.The Tg can be heighten by adding nano-particles of SiO₂ and the heat resistance of the curing film was enhanced.The result of the investigation was shown that UV-curable nano-hybrid coatings with excellent wear resistance and stability can be gained through the technics.