Aqueous dispersion of polyurethane anionomers from H₁₂MDI/IPDI, PCL, BD, and DMPA

Polyurethane anionomer dispersions were prepared from hydrogenated diphenylmethane diisocyanate (H 12 MDI) or isophorone diisocyanate (JPDI), poly(caprolactone) (PCL) diol, 1,4‐butane diol (BD), and dimethylolpropionic acid (DMPA). Upon neutralization of the DMPA with triethylamine (TEA), the NCO‐terminated polyurethane (PU) ionomers were self‐emulsified by adding water, followed by chain extension using triethylenetetramine (TETA) in aqueous media. Polyurethanes from H 12 MDI showed coarser dispersion and better tensile properties over those from IPDI. Polyurethanes prepared by the one‐shot method had better dispersion and tensile properties over those by the two‐shot method. When some of the PCL diol was replaced by DMPA or BD, tensile strength increased and ductility decreased due mainly to the increased chain rigidity and intermolecular forces.