Preparation of leafing Cu and its application in low infrared emissivity coatings

Leafing copper (Cu) powders with leafing degree from 20% to 67% were prepared by the ball milling method using raw non-leafing Cu, white spirit (WS) and stearic acid (SA) as precursor, slurry and lubricant, respectively. By optimizing the technical parameters, high leafing degree Cu powders were prepared and characterized by FTIR, XRD and SEM. Moreover, the infrared emissivity of Ethylene–Propylene–Diene Monomer (EPDM)/Cu coatings obtained by a simple preparation method using EPDM as organic binder and Cu with different leafing degrees as inorganic pigment was examined. It was demonstrated that the leafing degree of as prepared Cu plays an important role in decreasing the emissivity of EPDM based coatings, and the lowest emissivity value can be as low as 0.10. The study provides a simple effective way to greatly decrease the emissivity of coatings.