22.5 Polymerization Procedures

Bulk Polymerization

  • Bulk polymerization are those in which only the monomer (or reactants) plus possibly an initiator or a catalyst are added to a reactor vessel.

  • In other types of polymerization, a solvent or water is also added.

  • Bulk polymerization often produce higher purity polymers and in general require simpler separation procedures.

  • e.g: for the production of polystyrene, polyethylene, polypropylene, polyethylene terephthalate (PET) and nylon.

Solution or Solvent Polymerization

  • Solution polymerization is often used for those applications in which the polymer is required in solution form.

  • Surface coatings and impregnated compositions are among the commonest examples where the polymer is applied in solution.

Emulsion Polymerization

  • Emulsion polymerizations generally produce polymers with very high molecular weights. As a consequence, emulsion processes are often used for the production of polymers requiring high molecular weights such as Styrene-Butadiene elastomer (SBR) and Teflon.

Suspension Polymerization

  • Suspension polymerization processes are used for about 90% of all PVC produced. In addition, major amounts of polymers are produced using other olefins, including styrene and methyl methacrylate.