Abstract:A short-segment fluorinated chain extender (HFIP-IPDI-TMP) was synthesized and applied to an aqueous UV-curing system to prepare a UV-curable waterborne fluorinated polyurethane (UV-WFPU) emulsion. The structure of HFIP-IPDI-TMP was characterized by FT-IR and 1H-NMR. The effect of the fluorine chain extender on the emulsion particle size, mechanical stability of the emulsion, dynamic mechanical properties, water contact angle, surface morphology and mechanical properties were investigated. The results show that the emergence of HFIP-IPDI-TMP effectively improves the hydrophobicity and surface roughness of UV-WFPU films. Due to the increase of HFIP-IPDI-TMP content, the emulsion particle size, glass transition temperature and damping factor are gradually increased, and the elongation at break is decreased. When the fluorine content of organic fluorine is 3.5%, the UV-WFPU3 has the best hydrophobic property, and the water contact angle of the film is 96°, the particle size of the emulsion is 52.3 nm, and the tensile strength of the cured product is 12.31 MPa, and the elongation at break is 213%.