PVC Suspension Polymerization

METHOCEL™ cellulose ethers are time tested suspending agents for vinyl chloride polymerization providing particle size control, uniform particle size distribution, and porosity. A suspension agent that provides consistent performance during the polymerization process yielding PVC with a tailored specification.

An important characteristic of polyvinylchloride (PVC) is its ability to absorb additives, such as plasticizers, stabilizers, and pigments, quickly and in sufficient quantities. To achieve this goal a defined level of porosity is required which is often obtained at the expense of bulk density. The balance of porosity and bulk density is a constant issue for the suspension PVC producer, who is striving for the best compromise.

The particle morphology of PVC is partly influenced by polymerization conditions (temperature, reactor size, stirring conditions, etc.). The largest influencer is the selection of the surface-active suspending agent. Suspending agents reduce interfacial tension and facilitate the dispersion of vinyl chloride monomer droplets. The suspending agent also reduces droplet size and encapsulates them in a protective film, preventing the droplets from coalescing during polymerization.