EFFECT OF SURFACTANT TREATMENT ON THE FORMATION OF BOUND POLYMER ON TITANIUM-DIOXIDE POWDERS

The dispersibility of agglomerates into polymeric media is affected by the interactions between the medium and the particles and between the particles themselves. In this work, we have used the amount of bound polymer as a measure of interfacial interactions between the particles and the medium. Titanium dioxide powders with surfaces modified with silica and/or alumina were analyzed for their interactions with various liquid media by suspending them in different solvents and monitoring dispersion stability for given periods of time. Applying the concept that materials which have cohesive energy densities in close range are compatible, data for the solubility parameters of liquids have been used to characterize the pigment surface. The adsorption of surfactants onto the particle surface will modify its characteristics, and consequently, the interfacial interactions with various media. Determination of the bound polymer in dispersions of different coated titania particles in linear low density poly(ethylene) showed better interactions between the polymer and the filler particles for surfactant treated powders.