Low Voc Single-component Waterborne Polyurethane Dispersions

The research results of one-pack crosslinkable water-bore polyurethane oligomer having low viscosity are reported. A series of water-bore polyurethane dispersion (PUD) were synthesized with bulk polymerization by use of (meta) aliphatic isocyanate (TMXDI), dimethylolpropionic acid (DMPA), trimethyiolpropane (TMP) and low viscosity polyester made by us as primary material. In the synthesis of PU oligomer, two kind of different synthetic processes were researched, the effects of molecular weight of polyester, ratio of reactants, synthetic dispersion process and reaction conditions on dispersiablity of PU oligomers were furtherly investigated. To improve the properties of coatings formed from those PUD, different chemical crossfinkers and additives were used.