| It is well known that metal corrosion has been causing huge losses. To reduce the losses people have been trying hard to improve the corrosion resistance of coating. The emergence of nano-materials has brought new opportunities and challenges to the coating industry . Nano-ZnO is a new high-performance and fine inorganic materials, and has a lot of excellent performance. So far the reaserch of protective effect of nano-ZnO modified coating has been still at an exploratory stage inland and abroad. In particular, the influence of anti-infiltrate of media of the nano-ZnO modified coating remains at a simple qualitative stage. Addition, the systematic quantitative research is rare, and the anti-corrosion mechanism is not studied thoroughly. It is worth to study deeply.Here to solve the problems of the reunion of nano-ZnO and its poor combined ability with coating, we develop the study of related modification firstly, then the anti-corrosion and other performance of acrylic polyurethane coating adding modified nano-ZnO. The main conclusions of the work are as follows:1)The modification effect of titanate coupling agent KH201 is the best of the three kinds of coupling agents (titanate coupling agent KH201, silane coupling agents KH560 and KH550) by the analysis of FT-IR and SEM. The modified nano-ZnO was Nano-dispersed state uniformly in organic solvents. On this basis, we find optimum conditions of titanium coupling agent modification: the content of KH201 is 3.0wt% nano-ZnO , the content of isopropanol is 4 times quality of nano-ZnO, the reaction temperature is 30℃, stirring time is 60min.2)Through analysis and evaluation the anti-corrosion, anti-salt water, UV absorption capacity of the different contents(0.05wt%, 0.5wt%, 1.0wt%, 2.0wt%) of titanate modified nano-ZnO coating by EIS, salt test, ultraviolet spectrum, the result is the 0.5wt% content of nano-coating has the best performance. Thus we are sure that the best adding content of modified nano-ZnO is 0.5wt%.3) Compare three kinds of coatings' (the best modified nano-coating, the same proportion of the non-modified nano-ZnO composite coatings and acrylic polyurethane varnish ) corrosion resistance, heat resistance, mechanical properties, etc., the result is that modified nano-coating's corrosion resistance, heat resistance is superior to the other two coatings, but its mechanical properties aren't be improved. 4) The best conditions of macromolecule PMMA grafted nano-ZnO are: the content of KH570 is 4.0wt% nano-ZnO, the content of evocating agent-ammonium persulfate is 2.0wt% MMA monomer, the content of monomer is 3 times quality of nano-ZnO particles, the temperature is 75℃in oil bath, the experimental time is 5h. It has been proved that graft is successful by FT-IR, test of contact angle and SEM.5) Through testing and analysis the performance of acrylic polyurethane coating added the PMMA grafted nano-ZnO, the results show that the mechanical properties of composite coating have improved greatly, and its anti-corrosion performance is superior to the titanate modified nano- coating.
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