Fluorocarbon‐ containing hydrophobically modified poly( N‐isopropylacrylamide)

Abstract

Abstract A fluorocarbon‐modified ply( N ‐isopropylacrylamide) has been synthesized by copolymerization of N ‐isopropyl acrylamide with a small amount of acrylate or methacrylate containing a perfluoroalkyl group. It was found that the hydrophilicity of macromolecular backbone is an important factor to the solution properties of the copolymers and that hydrophobic association between fluorocarbon group is stronger than that between the corresponding hydrocarbon analogies. The viscosity of some of the copolymer solutions was very sensitive to temperature. It was dilatant at higher fluorocarbon comonomer content ( 0. 20–1.0 mol%) and was Newtonian at very low fluorocarbon comonomer content (0.03–0.2 mol%). Evidence for hydrophobic association of the fluorocarbon groups was obtained from the effects of adding NaCl and surfactants on the solution viscosity. The LC‐ST properties of these copolymers were studied by DSC method and this was also found to be consistent with hydrophobic association between the fluorocarbons.