STUDY OF ANIONIC POLYURETHANE IONOMER DISPERSANT

Anionic polyurethane ionomers designed for use as dispersants in water -soluble acrylic baking enamels were synthesized, and their structures were confirmed by infrared analysis, in on aqueous media, the surface tension of the polyurethane ionomers with different ionic or mixed io nic groups was found to increase with increased concentration of ionic groups, because of the orientation of hydrophobic groups at the air-w ater interface. ii was also found that viscosity in water is higher fo r a polyurethane ionomer with L-2,5 diaminovaleric acid hydrochloride than for a polyurethane ionomer with dimethylol propionic acid. Polyur ethane ionomers with dimethylol propionic acid, p-amino benzoic acid, and mixed dimethylol propionic acid/p-amino benzoic acid were better d ispersants for the wetability and dispersion of titanium dioxide in th e water-soluble acrylic enamels. The degree of dispersion of titanium dioxide was Found to improve with increased agitation time and anionic polyurethane ionomer concentration. in addition, polyurethanes with d imethylol propionic acid or p-amino benzoic acid or mixtures of these acids improved titanium dioxide dispersion.