STRATEGY FOR THE EVALUATION AND COMPATIBILIZATION OF PARTICULATE INCLUSIONS FOR USE IN MOLECULAR AND MACROMOLECULAR MEDIA

The quality of the dispersion of particulate solids in low and high mo lecular weight media depends on the interfacial forces that govern the wetting and stabilization of the solids. An understanding of these fo rces enables rational selection of compatible powder-fluid systems, or signals the need to provide some compatibilizers to aid dispersion. I n this paper we present a strategy for evaluating particle-fluid inter actions based on assessing the stability of solids in a spectrum of lo w molecular weight fluids. For a coarse evaluation of the dispersibili ty tendencies, we show how these results can be visualized in terms of a three-dimensional graph in which partial solubility parameters are the coordinates. For a more refined evaluation of dispersibility, we e xtend the data analysis to two-dimensional dispersibility maps in whic h donor and acceptor numbers of the fluids are coordinates. To exempli fy the approach, experiments using three grades of titanium dioxide pa rticles are presented. The methods are also sensitive enough to quanti fy the effects of surfactants added to compatibilize the titania parti cles with polyethylene.