Development of corrosion protection performance electrochemical exfoliating graphene – polymer composite coatings

• Main Authors: Andita Nataria Fitri Ganda, 納塔莉亞
• Other Authors: Ching-Yuan Su
• Format: Others
• Language: en_US
• Published: 2017
• Online Access: http://ndltd.ncl.edu.tw/handle/q48f25

碩士 === 國立中央大學 === 機械工程學系 === 105 === Nanocomposite coatings with electrochemical exfoliating graphene as a filler are developed to enhance the corrosion protection on metal substrates. Polyurethane and epoxy were used in this study. Using simple method to produce electrochemical exfoliating graphene (EC-Graphene) into polymer matrix. EC-Graphene was used because it has a low production cost, easy to produce and environmentally friendly. Large and small flake size graphene were explored to improve the corrosion resistance of composites. EC-Graphene flakes of two different average sizes (large: 13.35 µm2 and small: 2.87µm2) were prepared by a probe tip sonicator. The composites were prepared with varying content of graphene and the electrochemical measurement was conducted in sodium chloride solution. The results show that EC-Graphene has a good dispersion either in polyurethane or epoxy matrix. And also it can be coated on the metal surfaces such as copper and carbon steel. All filler could enhance the corrosion resistance of the composites. Hence we found that EC-Graphene with a large flakes size superior to EC-Graphene with a small flakes size. In low concentration of sodium chloride (0.1 M), adding 0.5 wt% large EC-Graphene into polyurethane can lower the corrosion rate to 4.0×10-4mm/year which is much better than the pure polyurethane. While for epoxy, the lowest corrosion rate was achieved within adding 0.75 wt% of large graphene with the value 2.3×10-5 mm/year. For the application of coating system, we also tested stacking Epoxy/Polyurethane/ EC-Graphene composite coatings in 3.5 wt% NaCl. Coating used layer by layer system with Epoxy/ EC-Graphene as base coat or primer coat and Polyurethane/ EC-Graphene as outer coat coated on carbon steel. We could obtain the corrosion value up to 1.81×10-5 mm/year. Furthermore, the facile and ecofriendly method would be promising process fabricating graphene-based nanocomposites and develop their application in the anticorrosion field.