Abstract: Fluorinated polyurethane prepolymer(FPU) was synthesized using 2,4-toluene diisocyanate(TDI), poly(ethylene glycol) adipate(PEA), dimethylol propionic acid(DMPA), fluoride monohydric alcohol(F-OH). FPUSi was then synthesized by the in situ acylation reaction of isocyanatopropyltriethoxysilane(Si-NCO) with FPU forming a polymer bearing triethoxysilyl groups. The structures of polymers and self-assembled fluorocarbon films were characterized by FT-IR. The surface properties of self-assembled films were tested by atomic force microscopy et al. FPU and FPUSi showed thermal stability with 5% mass loss at 178 ℃ by thermal gravimetric analysis in nitrogen. The contact angle of the obtained FPUSi self-assembled film was improved to 81°. The tribological experiment showed that the self-assembled films had a very low friction coefficient(about 0.09) and good anti-wear properties under a load of 400 mN. The improved tribological properties of the modified substrate were attributed to the good adherence of FPUSi self-assembled films on the substrate and synergy of FPUSi matrix.

Key words: friction, fluorine and silicon modified polyurethane, self-assembly films