Molecular interactions of carboxylated urethane acrylate ionomers in low-polarity and polar solvents

Carboxylated urethane acrylate ionomers that have a small number of ionic g roups per chain were synthesized with varying the molecular weight of soft segment, the degree of ionization, and the sort of diisocyanate. The effect of intra- and intermolecular interactions on solution properties was studi ed by viscosity measurements in low-polarity and polar solvents. In a low-p olarity solvent (1,4-dioxane), ionomers showed almost no intramolecular int eraction at dilute concentration and a small degree of intermolecular inter action at high concentrations, resulting from a small number of ionic group s per chain. In a polar solvent (dimethylacetamide, DMAc), ionomers showed typical polyelectrolyte behavior, even though ionomers have a small number of ionic groups per chain. Intermolecular interaction caused by polyether s oft segment, phenyl group, and hydrogen bond between urethane acrylate iono mer chains contributed to the increase of reduced viscosity at low concentr ation.