Polymerization pilot plants
Each of the systems that we have designed and built under this category of projects can be described by reference to one of the following polymerization processes:
Bulk or block polymerization
This process is the simplest in terms of formulation, and is conducted in the absence of any solvent or dispersant. A monomer, polymer and initiator are the only components. Applications include most step-growth and many chain-growth polymers.
Solution polymerization
Involves a liquid monomer in the presence of a solvent and catalyst. The solvent absorbs the heat of polymerization by a rise in temperature or vaporization. The monomer, solvent, initiator and polymer can exist in a soluble or insoluble phase.
Condensation polymerization
A process in which water or some other substance separates from two or more of the polymer molecules as a result of their combination.
Suspension polymerization
If the monomer is insoluble in water, bulk polymerization can be carried out in suspended droplets. The water phase serves as the heat transfer medium. In the continuous phase, conversion does not affect viscosity thus enabling efficient heat transfer to the reactor walls.
Emulsion polymerization
Droplets of monomer are emulsified in a continuous phase with water using a surfactant. Free-radical initiators migrate into the stabilized monomer droplets (known as micelles) to initiate polymerization.
Slurry phase polymerization
A process in which an olefin monomer and optional comonomer are polymerized in the presence of a catalyst in a diluent. The solid polymer product is suspended and transported in this slurry.
Gas phase polymerization
This method is used with gaseous monomers such as ethylene, tetrafluoroethylene and vinyl chloride. The monomer is introduced under pressure into a reaction vessel containing a polymerization initiator. Once polymerization begins, monomer molecules diffuse to the growing polymer chains. The resulting polymer is obtained as a granular solid.