Electrophoretic deposition of waterborne ultraviolet (UV)-curable coatings based on microgels

Microgels are novel functional polymers with an intramolecular crosslinked structure that can significantly improve the mechanical properties of coatings. We demonstrate herein for the first time successful fabrication of microgels based on branched poly(ethylenimine) (PEI) and their incorporation into water-soluble polyacrylate (WPA), with subsequent preparation of compact coatings via electrophoretic deposition (EPD) and ultraviolet (UV) radiation. The films including the microgels exhibited tensile strength and elongation at breakage values above 6.82 MPa and 72.09%, respectively. The coatings showed good thermal stability, decreased water absorption, outstanding durability, and rust resistance after immersion in 5 wt% NaCl solution for 7 days at 40°C. This work provides a new strategy that can be readily applied to a variety of conductive substrates.