Anionic polyurethane emulsion were synthesized by reacting hexamethylene diisocyanate with polyester prepolymer composed of poly (tetramethylene adipate) glycol and trimellitic anhydride.
The effect of ionic group content, 1.4 butanediol content, NCO/OH index on the properties of polyurethane ionomer were evaluated. With increasing ionic group content, the glass transition temperature increased, but the ionic group content had little effect on the melting temperature and the crystalline melting enotherm. The crystallinity was found to decrease with the increase in 1.4 butanediol content and NCO/OH index.
Change in glass transition temperature, crystalline melting endotherm and crystalline melting temperature were examined by differential scanning calorimetry. Also mechanical properties were tested by tensile test.
The viscosity of emulsion with changing ionic group content and solid percent was also examined.