Synthesis and solution properties of telechelic poly(2-isopropyl-2-oxazoline) bearing perfluoro end groups

Abstract

Amphiphilic telechelic poly(2-isopropyl-2-oxazoline) (M_n = 7.7 kg mol⁻¹) end-capped with 1H,1H,2H,2H-perfluoro-1-decanyl end groups (FPIPOZ) was prepared through cationic ring-opening polymerization followed by the ligation of alkyne–azide cycloaddition. At room temperature, FPIPOZ self-assembled into flower-like micelles in water above cac (0.35 g L⁻¹). In comparison with its precursor polymer N₃PIPOZ, the FPIPOZ aqueous solution had a lower T_c, a reduced phase transition enthalpy, and a much lower degree of crystallization. When exposed to THF vapor, an initially smooth FPIPOZ film reassembled into discs comprised of multiple lamella layers on silicon wafers, according to a THF vapor annealing experiment. This is the first observation of such an assembly pattern for PIPOZ. The N₃PIPOZ films, on the other hand, generated fibers on the surface upon exposure to THF vapor. The distinct surface assembly behaviors of FPIPOZ and its precursor N₃PIPOZ during solvent annealing added to our knowledge of polyoxazoline phase behaviors.