Research On The Preparation Of Wear Resistant Superhydrophobic Coatings Based On Powder Paint

Powder coating has the advantages of high film forming rate,no organic solvent,excellent durability and low energy consumption,etc.It is widely used in many industrial fields such as furniture,home appliances and architecture.However,it is found that the surface of the coatings is difficult to be cleaned when the powder coating was contaminated by the outside in practical applications.Therefore,the development and preparation of powder coatings with self-cleaning effects on the surface has become an important research direction in this field.The superhydrophobic surface produced by the lotus leaf effect has the effect of water repellency and self-cleaning.If the superhydrophobic technology can be applied to the surface of the powder coating to make it self-cleaning in practical applications,it can provide people with a great value in practical applications.Powdered resin and modified superhydrophobic SiO₂ particles are used as raw materials to prepare powder super-hydrophobic coating by adding organic solvent and brushing it to substrates.The surface of the fabricated coatings could be superhydrophobic and they have a high wear resistance because of the molten resin.The superhydrophobic coating prepared from powdered polyester resin could withstand 1000 cycles of finger-abrasion,while the coatings prepared with TPU and PTFE resin are slightly less durable with a durability of 300⁴00 cycles.The superhydrophobic powders were prepared by a melt-crushing method,and the powder super-hydrophobic coatings were prepared by powder electrostatic spraying technology.The contact angle of the water droplet on the surface of the coating reached to 156±4.6°,while the rolling angle was about 1.0°.The morphology inside coatings showed a porous structure.The mechanical wear resistance of the surface of the coating was tested.The results showed that the coating prepared by PMMA resin had the best wear resistance.After 80 times of abrasion by the abrasion tester,the water droplets were difficult to desorb on the surface of the coating but the WCA was still remains at around145°.In addition,the coating also had a great chemical and UV radiation resistance.After soaking in acid-base solution with pH=1¹3 for 24 h,the contact angle of water droplets on the coating surface could maintain at about 150°.On the basis of powder electrostatic spraying technology,we took methods of doping particles,resin composite and spraying modified superhydrophobic nano-coating on surface to enhance the mechanical durability of the powder coating surface.The experimental results showed that the wear resistance of powder coating was not improved obviously after adding a certain amount of large particles.When the PMMA and epoxy resin were combined,the number of abrasion cycles that the powder coating could withstand increased from 80 to 300.Modified superhydrophobic nano-coating was sprayed on the surface of the powder coating and a certain of micro-rough structure is constructed on the inner wall of the resin.After 150 rounds of coating,the coating can withstand 150 cycles of abrasion of the grinding wheel,which improved the abrasion resistance compared with the original coating.In the experiment,it is found that the modified silica particles could be superoleophobic when a certain amount of TEOS was added in the process of modification.The fabricated superamphiphobic SiO₂ particles and resin powders were used as raw materials and through dry mixing method to prepare the powder coatings.After spraying the powder through electrostatic spraying technology on the conductive substrates,the contact angle of oil droplets was 154.7°and the rolling angle as low as 1.0°.The durability test of the prepared superamphiphobic powder coating shows that the surface could still maintain a certain degree of oleophobicity after 50 cycles of finger abrasion.Placed the coating in the soybean oil for 7 hours,the coating surface almost did not leave any oil stains and oil droplets on the coating surface still easily roll away.At the same time,during the progress of corrosion in acid and alkali solution for 24 h,the contact angle of oil droplets always remain above 150°while the sliding angle was under 20°.This result displayed the great durability for anti-oil.While spraying a certain amount of modified superamphiphobic nano-coating on the powder coating,the superamphiphobic nano silica contained in the coating adsorbed on the inner wall of the resin which constituted a certain structure roughness.The wear resistance and durability of the coating to oil droplets were significantly enhanced.After 700 times of finger abrasion or 72 hours of soya bean oil immersion,the coating surface still had certain oleophobic properties.