| Abstract: | A series of polyurethaneurea (PUU) aqueous dispersions were prepared via a prepolymer process from polyester polyol, α,ω‐dihydroxypoly[(3,3,3‐trifluoropropyl) methylsiloxane] (PTFPMS), dimethylolpropionic acid, isophorone diisocyanate, and ethylenediamine. These anionic‐type aqueous dispersions were stable at the ambient temperature for more than 6 months, with particle sizes ranging from 69 to 127 nm. For these aqueous dispersions, the surface tension decreased with increasing PTFPMS content, but the particle size increased with a maximum value. The film prepared from the PUU aqueous dispersion consisting of 5 wt % PTFPMS (APU‐FS‐5) exhibited excellent waterproof performance. Furthermore, the tensile strength of the APU‐FS‐5 film increased nearly 3 times compared with that of the PUU film without PTFPMS, whereas the elongation at break only decreased a little; this indicated that the water‐resistant and mechanical properties could be enhanced markedly and simultaneously for the PUU films containing both silicon and fluorine groups. The experimental results showed a high degree of hydrogen bonding for urea groups and an increased microphase‐separation degree between the hard and soft segments in the PTFPMS‐modified system, which resulted in the excellent mechanical properties of these films. © 2006 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 44: 3365–3373, 2006 |
