AQUEOUS DISPERSION OF POLYURETHANE IONOMERS FROM HEXAMETHYLENE DIISOCYANATE AND TRIMELLITIC ANHYDRIDE

Polyurethane (PU) ionomers were prepared from trimellitic anhydride (TMA), poly(tetramethylene adipate) glycol (PTAd), and hexamethylene diisocyanate (HDI) in acetone. Upon neutralizing the carboxylic groups with a tertiary amine (TEA), and adding water to PU ionomer solution, followed by removing the acetone, stable aqueous PU dispersions were obtained. Effects of interionic molecular weight and nonionic hydrophilic segment, viz. monofunctional ethylene-propylene oxide ether on particle size, emulsion viscosity, mechanical, and viscoelastic properties of the emulsion cast films were examined.