MOLECULAR INTERACTIONS OF CARBOXYLATED URETHANE ACRYLATE IONOMERS IN LOW-POLARITY AND POLAR SOLVENTS

Abstract

Carboxylated urethane acrylate ionomers that have a small number of ionic groups 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 studied by viscosity measurements in low-polarity and polar solvents. In a low-polarity solvent (1,4-dioxane), ionomers showed almost no intramolecular interaction at dilute concentration and a small degree of intermolecular interaction at high concentrations, resulting from a small number of ionic groups 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 soft segment, phenyl group, and hydrogen bond between urethane acrylate ionomer chains contributed to the increase of reduced viscosity at low concentration.