Micellar and rheological properties of some sodium deoxycholate-based poly(ester ether)urethane ionomer biomaterials in N,N-dimethylformamide solutions

Abstract In this work new sodium deoxycholate-based poly(ester ether)urethane ionomers are prepared. The micellar and rheological behaviour of these polyurethanes in N,N-dimethylformamide solutions are studied by means of transmission electron microscopy, dynamic light scattering, steady state fluorescence measurements and rheological oscillatory tests. For poly(ethylene oxide)- and poly(propylene oxide)-based polyurethanes spherical core-shell micellar morphology was obtained, whereas for pluronic-based polyurethanes micellar aggregate morphology was obtained. Increased values of critical micelle concentration were determined for the polyurethanes containing more solvophilic poly(ethylene oxide) segments as found for Pluronic block copolymer surfactants. It was found that the type of polyether macrodiol influences the micellar morphology and rheological behaviour. Viscosity of the polyurethane solutions is influenced by their concentration, micellar network, molecular weight and hard segment content of polyurethane. Shear thinning (pseudoplastic) behaviour of the polyurethane solutions was revealed. Gel-sol transitions and liquid-like behaviour were revealed by amplitude sweep tests. Gel-like behaviour and gel-sol transitions were revealed by frequency sweep tests.