Preparation and Properties of Aqueous

Waterborne polyurethane as a new polymer dispersion was synthesized by usingrelatively hydrophilic polyols. This polymer was prepared from polycaprolactonediol (Capa 225), toluene diisocyanate (TDI), 1,4-butane diol (BDO) as chain extender, and dibutyltin dilaurate catalyst. Grafted polyurethane was prepared with chlo-rinated poly(ethylene glycol monomethyl ether) (PEGMME) in the presence of sodium hydride (NaH). Chlorinated PEGMME was also prepared by reaction of PEGMME with thionyl chloride in dried toluene. FTIR and 1H NMR of the waterborne polyurethanes were used to characterize the grafted PU. The effects of various molecular weights of PEG-MME as non-ionic hydrophilic segments were studied. The particle size and viscosity of dispersions were systematically analyzed. It is found that by increasing the molecular weight of the grafted PEGMME, the particle size of dispersed polyurethane is decreased, and viscosity is increased