Study on Synthesis of Environmental Waterborne Polyurethane

A MDI-based waterborne polyurethane emulsion(PU) was synthesized by the reaction of polyester glycol(PBA), di-methylol propionic acid(DMPA) with 4,4`-diphenylmethane diisocyanate (MDI) instead of toluene di-isocyanatotoluene(TDI) because of its low toxicity, low saturated vapor pressure. The factors influencing the properties of waterborne polyurethane emulsion were discussed. It was observed that the appearance and properties of the PU emulsion were nearly related with the ratio of NCO/OH(R) and the amount of DMPA.