Synthesis and characterization of a polystyrene-type polymer bearing a cyclic perfluoroalkylene group

Abstract

Perfluoroalkyl-containing aromatic compounds are predicted to have fascinating material properties. In this work, a styrene derivative bearing a cyclic perfluoroalkylene group, –(CF2)4–, was synthesized and polymerized to afford the corresponding polymer. The styrene derivative was obtained via the Ullmann coupling of I–(CF2)4–I with 3′-bromo-4′-iodoacetophenone, NaBH4 reduction of the ketone moiety, and dehydration using P4O10. Free-radical polymerization (FRP) of the styrene derivative afforded polymer with number-average molecular weight (Mn) and dispersity index (DI) of 1.1 × 104 and 3.1, respectively. The thermal stability of the synthesized polymer (Td10% 359 °C, Tg 149 °C) was greater than the previously reported n-C4F9-substituted polystyrene (Td10% 296 °C, Tg 19 °C). The increased thermal stability of the newly synthesized polymer is hypothesized to arise from the lack of terminal CF3 moieties. The cyclic perfluoroalkylene-substituted polystyrene exhibited hydro- and oleo-phobicities comparable to those of the n-C4F9-substituted polystyrene, suggesting that the introduction of cyclic perfluoroalkylene groups instead of the commonly used Rf groups may have the potential to develop thermo-resistant polymers with hydro- and lipo-phobicity. Thew newly synthesized polymer is suitable for a variety of applications requiring high-Tg optical polymeric materials.