Synthesis and characterization of polyurethane anionomer

An isocyanate-terminated prepolymer prepared from 1,1'-methylenebis (4-isocyanatobenzene) (MDI) and alpha-hydro-omega-hydroxypoly (oxytetramethylene) (PTMG) was chain extended with 2,2-bis (hydroxymethyl) propionic acid (DMPA). The resulting carboxy group-containing polyurethane was converted into a polyurethane anionomer by treatment with potassium acetate, magnesium acetate, or N,N-dimethylpiperazine. The chemical structure of the polyurethane anionomer was characterized with respect to its mechanical, dynamic viscoelastic and thermal properties.