SYNTHESIS
PVC macromolecules i.e. long chains are made by joining vinyl chloride through the process of polymerization. The monomers are in a solid, chemically stable form and therefore do not pose a threat to humans as compared to other monomers which exists in gaseous state. Vinyl chloride is a gas at room temperature and pressure but it is usually stored as a liquid by applying pressure.

Making the Monomer:
Initially the Vinyl Chloride was produced by reacting acetylene with hydrochloric acid catalyzed by mercuric chloride. However this has become obsolete now and the monomer is more popularly produced from Ethylene and Chlorine. The ethylene is obtained from the thermal cracking of Naphtha in the basic petrochemical industries while chlorine is …show more content…
Suspension Polymerisation
2. Emulsion Polymerisation
3. Bulk polymerization
All these processes follow the same procedure but yields different resin sizes. The Vinyl chloride along with water is introduced in the reactor along with an initiator and required additives. The reaction vessel is continuous stirred to maintain a uniform suspension composition. Water is continuously added as the PVC formed is denser than its monomer. The reaction vessel is water-cooled for the reaction is exothermic.
The PVC resins produced through suspension polymerization is usually granular in nature with some degree of porosity whereas emulsion polymerization yields small particle powders. In bulk polymerization, the degree of porosity in the resins is generally higher.
The initiators break down to start radical polymerization in which the monomers are continuously added to the chains by radical formation. The monomers are usually arranged in such a way that the chloride groups are attached to alternative carbon atoms which usually generates an atactic stereochemistry. Once complete, the PVC slurry is treated to remove the unpolymerised monomers left. The polymer is then dried to remove water and the powder is shaped into