Preparation Of Nano-slurry And Its Application In Water-based Anti-corrosion Coatings

In this paper,the dispersion of nano-powder in waterborne system and its application in waterborne anticorrosion coatings. The whole paper includes three parts as follows:The first part is mainly study the stability of water-based nano-slurry.The modified nano-TiO2 infrared spectroscopy showed that Al3+ have been deposited to the surface of nano-titanium dioxide particles and the SDS was adsorbed to the surface of nanoparticles. Nano-particle size distribution chart showed that the prepared slurry has reached to nanoscale dispersion,and TEM photo revealed that nanoparticles are evenly dispersed in the water,and storage stability can reach 60 days at room temperature. Then factors affect the stability of two nano-slurry were full studyed.Both of the two kinds of nano-sLurry's best dispersion methods are high-speed stirring for 40 minutes and plus ultrasonic ultrasound for 10 minutes, and the ultrasound frequency is 5 second per time.731A is the best dispersant for two kinds of nano-slurry,and optimum dosage is 0.3%.X-405 is the best wetting agent for nano TiO2 slurry,and the optimum dosage is 0.2%,while wetting agent 875 is the best for nano-SiO2 slurry, and the optimum dosage is 0.15%.The best pH value of nano TiO2 slurry is 10,while the best pH value of nano SiO2 slurry is 11.The optimum dosage of bentonite as anti-sedimentation agent for two kinds of slurry is 0.2%.The second part is mainly study application of two kinds of nano-slurrys in the water-based anticorrosion coatings.Two kinds of nano-slurrys were added to coatings, and a variety of performance tests showed thatthe nano-SiO2 and nano-TiO2 were added to the water-based acrylic anticorrosion paint,their respectively optimum dosage were 4%o and 2%o,and 2%o of the nano-TiO2 was add to the paint to improve various properties was better than 4%o of nano-SiO2.If they were added to paint with mixtured in different proportions,the results showed that their optimum proportion is 2:1 and the optimum dosage was 5%o,and the improvement of water-based acrylic anticorrosion paint is between adding 2%o of nano-TiO2 and 4%o of nano-SiO2,and that means the order of improvement for variety of solvent resistance and aging resistance is:nano TiO2>nano-SiO2 compounded with nano-TiO2(which mSiO2: mTiO2=2:l)>nano-SiO2.The nano-SiO2 and nano-TiO2 were added to the water-based epoxy anticorrosion paint,their optimal dosage were 3%o. Added mixtures to paint which they were mixtured in different proportions, the results showed that their optimum proportion is 1:2 and the optimum dosage was 3%o.The order of a variety of solvent resistance and aging resistance for water-based epoxy anticorrosive paint was the same as acrylic paint.Because of nano-SiO2 three-dimensional network structure characteristics,added it to water-based acrylic and epoxy anticorrosion primer in order to improve their density and variety of solvent resistance,and the respectively optimal amount were 4%o and 3%o.The third part is study the use of matching top paint and primer.Through supporting the use of various primer and paint,drew the conclusion that the coating worked best which added nano slurry both in its paint and primer,and its various properties have different degrees of increase compared with blank samples.Through comparison of coating that compose of blank primer matched with top paint which added nano slurry and another coating that compose of blank top paint matched with primer which added nano slurry,and result showed that nano slurry on relatively large range of performance improvement on a variety of properties of top paint.