Study On Preparation And Performance Of Grapheme/TiO₂Modified Water Borne Polyurethane Composite Coatings

Environmental issues gradually become the concern focuses of every person. Environmental friendly marine coatings gradually become a research focus. Cuprous oxide as the main composition of marine antifouling due to it polluted the marine environment, would be banned from use in the future. In recent years, many countries are moving research and development centers to environmentally friendly coatings to replace toxic antifouling coatings. And because of waterborne polyurethane with water as solvent, it was widely promoted as good environmentally friendly coating.But compared with the solvent-based polyurethane, the antibacterial action, surface property, mechanical property and water resistance of waterborne polyurethane are needs to improve. Nano-TiO2as one of photocatalytic nanomaterials is a hotspot of marine antifouling materials. It is widely used in the antibacterial coatings, this is due to the nano-TiO2has a good mechanical strength, conductivity and antibacterial properties. However, the nano-TiO2is very high surface energy, so particles tend to gather. And because the band gap width of nano-TiO2is wider, developing visible-light responsive photocatalysts is becoming a promising and challenging research area at the present time. The graphene can effectively prevent nano-TiO2gathered themselves together, and improve the visible the rate of light absorption, and enhanced photocatalytic antibacterial properties, electrical conductivity, and surface properties. The modification of waterborne polyurethane in marine antifouling comprehensive performance has greatly improved.In this dissertation, the authors obtain an efficient photocatalysts nano-TiO2by grapheme hybridization, under the hydrazine hydrate and ammonia solution. Then composite the waterborne polyurethane and graphene/TiO2photocatalysts in different graphen contents with ultrasonic method to get the modified waterborne polyurethane composite coating. The characterizations of the composite materials were systematically studied to get the suitable graphene content of the composite materials.When the graphene content is5%, the bacteriostasis of the graphene/TiO2modified waterborne polyurethane coating attain the best performance, and at the same time, has a good surface performance, water resistance and mechanical properties.