Anionic polyurethane dispersants APUDs were used as dispersing agents in formulation of waterborne paints. The APUDs were synthesized by three steps. In the first step, macromonomer diisocyanate having carboxylic acid was prepared by isophorone diisocyanate IPDI, dimethylol propionic acid DMPA in presence of acetone as solvent and dibutyltin dilaurate DBTDL as catalyst. Then, carboxylic polyure...