Preparation and properties of polyamido-amine dendrimer/polyurushiol composite coatings by stepwise electrophoresis deposition

The dendritic polyamido-amine/urushiol composite coatings were prepared by an efficient, controllable, green and convenient method via two steps of electrophoresis deposition. Under optimal mass concentration (6.8 wt%), the urushiol particles in the electrophoretic solution remained excellent dispersion state and uniform size distribution. In the first-step of electrooxidation polymerization of urushiol, the unsaturated side chains were successfully crosslinked and deposited on the surface of the anode to form a coating. In the second-step of the electrophoresis deposition, polyamido-amine dendrimers were crosslinked with urushiol molecules to produce the urushiol Schiff base compounds. Composite coatings contained compact and uniform structure and showed better thermal stability compared with unmodified urushiol coatings. In addition, the hardness, impact resistance, flexibility and adhesion were remarkably strengthened. Moreover, the medium resistance was also significantly improved.