Synthesis and characterization of polysulfone-g-poly(2-alkyl-2-oxazoline)s

Novel amphiphilic graft copolymers of polysulfone (PSU) possessing hydrophilic poly(2-oxazoline) (POx) side chains were synthesized via the 'grafting from' method. The cationic ring-opening polymerizations of 2-methyl-2-ozaxoline, 2-ethyl-2-ozaxoline, and 2-propyly-2-ozaxoline were initiated by chloromethylated polysulfone macroinitiator (with 15% benzylchloride content), synthesized by chloromethylation of PSU, in the presence of sodium iodide. The effects of reaction time and type of monomer on the yield, and degree of polymerization were investigated. The obtained polymers were characterized by proton nuclear magnetic resonance spectroscopy, Fourier transform infrared spectroscopy, and differential scanning calorimetry analyses. Thin films of graft copolymers were investigated by atomic force microscopy and contact angle measurements. The observed morphologies of thin films were consistent with the amphiphilic nature of the graft copolymers. The films showed temperature dependent surface hydrophobicity due to thermo responsiveness of POx.