Preparation and Characterization of Aqueous Polyurethane Polyol Used in Waterbore Two-Component Polyurethane Coating

Aqueous polyurethane(PU) polyols were synthesized from polyester polyol, toluene diisocyanate(TDI), dimethylolbutyric acid (DMBA) and diethanolamine(DEA). The structure of PU polyol and resulting polyurethane film were confirmed by the Fourier Transform Infrared Spectroscopy (FT-IR). The effects of NCO/OH and DMBA content on the particle size of PU polyol and resulting polyurethane films, which formed by the mixture of PU polyol and water-dispersible polyisocyanate, was investigated by dynamic light scattering analysis, dynamic mechanical analysis and measurement of the mechanical properties.The results show the increase in DMBA content or NCO:OH ratio may be used to decrease the particle size of aqueous polyurethane polyol, increase the Tg for two-component aqueous PU film and maybe adjust the mechanical properties of resulting film.