Effect of the Phase Ratio on the Particle Properties of Poly(vinyl chloride) Resins Produced by Suspension Polymerization

The effects of the dispersed phase to continuous phase ratio (weight of VCM (gr)/weight of water (gr) (phi = gVCM/gwater)) on the particle properties of a poly(vinyl chloride) (PVC) suspension were investigated experimentally. A series of experiments were performed with different phi values in a pilot-scale reactor. The cold plasticizer absorption of the resin decreased with phi. Scanning electron micrographs showed that by the reduction of y, many of the produced particles had a regular shape, a smooth surface, and greater porosity. An increase in phi caused a wider and multimodal particle size distribution of the produced PVC particles. The mean particle size and bulk density also increased with D, whereas the molecular weight and polydispersity index did not change. (C) 2008 Wiley Periodicals, Inc. J Appl Polym Sci 110: 2748-2755, 2008