Ultrafast electrosynthesis of high hydrophobic polypyrrole coatings on a zinc electrode: Applications to the protection against corrosion

Hydrophobic polypyrrole (PPy) coatings on zinc electrodes were prepared by a one-step electrochemical method. The process is ultrafast; 2 urn of PPy can be deposited in less than 3 s. It is thus compatible with industrial requirements for the coating of large surfaces for various industries (automotive, buildings, ships). The coatings obtained have apparent contact angles as high as 125 degrees and can thus be used as cheap highly hydrophobic surfaces. They have been fully characterized using various physicochernical techniques (EQCM, XPS) and their anticorrosion properties have been tested. It is found that postpolymerization heat treatment makes it possible to reach a situation where 1 mu m of polypyrrole is equivalent to 1 mu m of a zinc coating for preventing the corrosion of mild steel.