Primary particle stability in bulk polymerization of vinyl chloride at high ion strength

Abstract

Tetrabutyl ammonium tetrafluoroborate and tetrabutyl ammonium chloride dissociate completely in vinyl chloride (VCM). These salts, when added to colloidal dispersions of PVC primary particles in VCM prepared by bulk polymerization, cause the particles to flocculate, showing that the primary particles were electrostatically stabilized. When bulk polymerizations were carried out in the presence of the same quarternary ammonium salts, smaller primary particles were obtained than in additive-free polymerizations. Addition of tetrabutylammonium tetrafluoroborate to a suspension polymerization increased the porosity of the resin.