Synthesis and properties of polymers based on oligo(hexafluoropropene oxide) containing methacrylates and copolymers with methyl methacrylate

Three series of methacrylate homopolymers with oligo(hexafluoropropene oxide), (HFPO)(n), side groups and copolymers based on methyl methacrylate were prepared by free radical polymerization. Each series consisted of a polymethacrylate backbone with substituted HFPO side chains of different length ranging from the corresponding tri- and tetramers to a pentamer. In case of the (HFPO)(3)MA copolymers, glass transition temperatures decreased linearly with increasing (HFPO)(3)MA content over the entire composition range. In contrast, two different regimes were distinguished for (HFPO)(5)MA-containing copolymers, and also for the (HFPO)(4)MA homopolymer two T-g's were discerned. At low HFPO content the glass transition temperatures decreased with increasing (HFPO)SMA substitution. Above 50 mol % two glass transitions were observed, indicating microphase separation. Copolymers with only 10 mol % of(HFPO)(n)MA exhibited a low surface energy as is typical for highly fluorinated polymers. Dispersion force surface energies were determined by the Good-Girifalco-Fowkes-Young method and resulted in a minimum value of 11 +/- 1 mN/m.