Flocculation studies of non-aqueous sterically stabilized dispersions of polymer

Abstract

The incipient instability of non-aqueous sterically stabilized dispersions of polymer particles has been investigated. Flocculation was induced by decreasing the solvency of the dispersion medium for the stabilizing moieties, either by non-solvent addition or by cooling. The influence of such factors as the nature of the dispersion medium, the temperature, the non-solvent, the stabilizing moieties, the anchor polymer, the disperse phase, the particle size and the surface coverage has been examined.

Flocculation occurs in dispersion media which are of better solvency for the stabilizing moieties, in free solution, than the corresponding theta-solvents. It is apparently governed by the component of the soluble moieties for which the given flocculating dispersion medium is of least solvency. The results support Fischer' s general approach to steric stabilization.