Synthesis of a Waterborne Polyurethane-Fluorinated Emulsion and Its Hydrophobic Properties of Coating Films

In this study, a novel waterborne polyurethane-fluorinated acrylic (WFPU) hybrid emulsion was synthesized and introduced. The cross-linker aziridine was used to enhance the film-forming capacity and mechanical property of WFPU. FTIR and XPS results confirmed that WFPU latex was successfully prepared. WFPU has an excellent hydrophobicity, resulting in an obvious increasing of water contact angle from 58.5° to 92.5°. AFM measurements observed that a continuous polymer film was formed after adding the cross-linker, indicating an excellent film-forming capacity of the cross-linked WFPU. The influence of the amount of the cross-linker on the hydrophobicity and mechanical properties was also studied. Cotton coating experiments visually approved that the cotton hydrophobicity is effectively enhanced by WFPU and the cross-linked WFPU. These results indicated that the cross-linked WFPU containing 30 wt % of fluorinated acrylate and 2.93 wt % of cross-linker has a potential as a coating material for water repellent applications due to providing fantastic hydrophobicity, excellent film-forming capacity, and outstanding mechanical properties.