Self‐healing waterborne fluorinated polyurethane‐acrylate based on photoreversible reaction and hydrogen bonds

Abstract

The development of self‐healing materials is an effective strategy to improve the service life of polymer materials. In this study, self‐healing waterborne fluorinated polyurethane‐acrylate (WFPUA) containing UV‐responsive coumarin groups was prepared by Pickering emulsion polymerization using modified cellulose nanocrystal as a stabilizer. The effect of double bond‐terminated waterborne polyurethane (WPU) content on emulsion polymerization and latex film properties was mainly studied. Due to the dynamic reversibility of the coumarin groups and the synergistic effect of hydrogen bonds, the optimized sample (WFPUA‐30) had excellent mechanical properties and self‐healing properties. The tensile strength was 5.24 MPa, and the elongation at break was 267%. The self‐healing efficiency of tensile strength and elongation at break after 6 h of repair were 86.52% and 93.20%, respectively. In addition, due to the presence of fluorine‐containing groups, the water and oil contact angles of the latex film could reach 101.7°and 82.1°, respectively. This work broadens the way to manufacture self‐healing and multifunctional waterborne polyurethane‐acrylates.