surface control of thermosetting fluorinated polyurethane

In this paper, thermosetting fluorine-containing polyurethane (S-FPU) was synthesized through a novel method with two-step process and its surface properties was studied. Firstly, fluorine-containing epoxy compound (FO) was obtained by epichlorohydrin (ECH) and tetrafluoropropanol (TFP). Further, the fluorinated polyether polyols (FPO) was synthesized by cationic copolymerization of tetrahydrofuran (THF) with the FO, the fluorine was located on the side chains of the FPO and the molecular weight of FPO was controllable, besides, the molecular weight distribution of FPO was narrow. Finally, the S-FPU was prepared by FPO as soft segment, MDI as a hard segment and TEA as chain extender. The influence of fluorine enrichment on the surface properties of S-FPU was studied by controlling curing temperature, curing time and structure of FPO. In addition, the surface fluorine content of S-FPU and the surface hydrophobicity were studied in detail. The results showed that with the curing temperature decreased, the surface fluorine content of S-FPU increased, and when the curing time was more than 10 hours, the fluorine element did not migrate to the surface. What’s more, with the molecular weight of FPO increased, the surface fluorine content of S-FPU increased.