Novel cationic polyurethane-fluorinated acrylate hybrid dispersion was prepared with the copolymerization of styrene, butyl acrylate and fluorinated acrylate in the medium of crosslinked polyurethane by the initiation of benzoyl peroxide via phase inversion polymerization in order to increase the liquid resistance of general polyurethane-acrylate hybrid dispersions. The said polyurethane was synthesized in acetone from toluene-2,4-diisocyanate, N-methyldiethanolamine (MDEA) as a hydrophilic chain-extender, trimethylolpropane as a crosslinker, and soft polyester diol (PE1000) block. The influences of MDEA on particle diameter and Zeta potential of dispersions and surface properties of dispersion films were investigated. FTIR and TEM were used respectively to characterize the structure and the particle morphology of the resultant dispersions. The results show that the addition of MDEA will decrease the particle diameters of dispersions and hydrophobic properties of the dispersion films. With the MDEA content of about 13.15%, the morphology of the dispersion particle is sphericity and the diameter is about 253 nm. The surface free energy of the film is less than 25.1 mJ/m², and the attenuation rate of contact angle is about 0.38 (°)/min. At the same time, the treatment of the films with high temperature can decrease the surface free energy by more than 11.5%.

Key words: cationic polyurethane-fluorinated acrylate, hydrophilic monomer, surface free energy, immersion behavior