Synthesis and surface property of aqueous fluorine-containing polyurethane

A novel aqueous fluorine-containing polyurethane was prepared with a hydrop hobic macromonomer of a perfluoroalkyl group. Two representative properties of the polyurethane, initial particle diameter dispersed in water and surf ace free energy of coating films, were investigated. The macromonomer was s ynthesized by radical copolymerization of perfluoroalkylethyl acrylate and methyl methacrylate with a diol of chain-transfer agent in order to attenua te solubility and hydrophobic property. Anionic aqueous polyurethane was ob tained with a good hydrophobic film property by one-step condensation polym erization of the macromonomer with hydrophilic comonomers and successive io nization. The polyurethane showed an initial average diameter of less than 1100 nm in water and surface free energies of less than 19 dyn/cm. The wate r dispersion property and hydrophobic surface property of the polyurethane can be controlled by controlling the content and hydrophobic property of th e macromonomer. The incorporation of the macromonomer in the polyurethane b ackbone did not show a significant effect on the glass transition temperatu re, or the softness, of the polyurethane. (C) 2001 Academic Press.