Anionic polymerizations of perfluoroalkyl methacrylates and synthesis of well-defined ABC triblock copolymers of methacrylates containing hydrophilic, hydrophobic, and perfluoroalkyl groups

Anionic polymerizations of three perfluoroalkyl methacrylates, 2,2,2-triflu oroethyl- (1), 2-(perfluorobutyl)ethyl- (2), and 2-(perfluorooctyl)ethyl me thacrylates (3), were carried out in THF at -78 degrees C for 1 h with 1,1- diphenyl-3-methylpentyllithium in the presence of 5-fold lithium chloride. Poly(1) and poly(2) were obtained in quantitative yields and those possesse d predicted molecular weights based on the molar ratios of monomers and ini tiator and narrow molecular weight distributions (MWD, M-w/M-n < 1.15). Pol ymerization of 3 also proceeded quantitatively to give poly(3) showing very limited solubility. Sequential anionic copolymerizations of 2, tert-butyl methacrylate (tBMA), and 2(trimethylsilyloxy)ethyl methacrylate and the sub sequent deprotection of trimethylsilyl group afforded a series of well-defi ned ABC triblock copolymers by changing the additional order of three comon omers. H-1 NMR spectra of the resulting triblock copolymers suggested the f ormation of their micelles in the selective solvents. contact angle and X-r ay photoelectron spectroscopic measurements of the triblock copolymer films confirmed the enrichment of the poly(2) segment at the film surface in dry state and the surface rearrangement in respect to changing the environment al conditions. It was suggested that segmental sequence in the triblock cop olymers affected the structure in solution and at surface.