- May 17, 2019-

The product of the polymerization process is unmodified PVC. Before PVC can be made into finished products, it always requires conversion into a compound by the incorporation of additives (but not necessarily all of the following) such as heat stabilizers, UV stabilizers, plasticizers, processing aids, impact modifiers, thermal modifiers, fillers, flame retardants, biocides, blowing agents and smoke suppressors, and, optionally, pigments. The choice of additives used for the PVC finished product is controlled by the cost performance requirements of the end use specification (underground pipe, window frames, intravenous tubing and flooring all have very different ingredients to suit their performance requirements). Previously, polychlorinated biphenyls (PCBs) were added to certain PVC products as flame retardants and stabilizers.