Preparation and properties of waterborne polyurethane-urea anionomers. I. The influence of the degree of neutralization and counterion

Two series of waterborne polyurethane-urea anionomers were prepared by a polyaddition reaction with isophorone diisocyanate, poly(tetramethylene oxide) glycol (weight-average molecular weight = 1000), dimethylol propionic acid (DMPA), and ethylene diamine as chain extenders. Triethylamine (TEA) or 28:1 mol/mol ammonium hydroxide (NH4OH)/cupric hydroxide [Cu(OH)2] was used as a neutralization agent [NH(C2H5)3+ or NH4+/Cu2+ counterion] for the pendant COOH group of DMPA. The effects of the degree of neutralization and counterion on the particle size of the dispersion, the conductivity, and the antibacterial and mechanical properties of polyurethane-urea anionomer films were investigated. The particle sizes of the two sample series dispersion decreased with an increasing degree of neutralization. Aqueous dispersions of polyurethane-urea anionomers with particle sizes of 30-120 nm were stable for about 3 months. By infrared spectroscopy, it was found that TEA-based samples (T series) had higher fractions of hydrogen-bonded carbonyl groups in the ordered region than NH4OH/Cu(OH)2-based samples (S series). However, the fractions of hydrogen-bonded carbonyl groups in the disordered region of the S-series samples were higher than those of the T-series samples. The conductivities of the S-series film samples were higher than those of the T-series samples. However, the T-series film samples commonly had higher tensile strengths and initial moduli than the S-series samples.