The synthesis of polyvinyl chloride PVC from vinyl chloride monomer VCM involves a polymerization reaction, specifically a free radical chain polymerization. Here is the step-by-step mechanism for this process:1. Initiation:A free radical initiator, such as benzoyl peroxide or azobisisobutyronitrile AIBN , is added to the reaction mixture containing vinyl chloride monomer. The initiator is heated and decomposes into free radicals.Initiator 2 Free Radicals2. Propagation:The free radicals generated in the initiation step react with the vinyl chloride monomer, forming a new radical that can react with another vinyl chloride monomer. This process continues, creating a growing polymer chain.Free Radical + VCM VCM RadicalVCM Radical + VCM VCM-VCM RadicalVCM-VCM Radical + VCM VCM-VCM-VCM Radical...and so on3. Chain Transfer:During the polymerization process, chain transfer reactions can occur, which involve the transfer of the growing polymer chain's radical to another molecule, such as a solvent or another monomer. This results in the termination of the original chain and the initiation of a new chain.VCM-VCM-VCM Radical + Molecule VCM-VCM-VCM + New Radical4. Termination:The polymerization reaction is terminated when two radicals react with each other, forming a covalent bond and ending the growth of the polymer chain.VCM-VCM-VCM Radical + VCM-VCM Radical VCM-VCM-VCM-VCM-VCMConditions and reagents necessary for the synthesis of PVC from VCM:- Vinyl chloride monomer VCM as the starting material- A free radical initiator, such as benzoyl peroxide or azobisisobutyronitrile AIBN - A solvent, such as water or an organic solvent, to dissolve the initiator and control the reaction rate- Temperature control: The reaction is typically carried out at elevated temperatures 40-60C to facilitate the decomposition of the initiator and the polymerization process- Pressure control: The reaction is often performed under pressure to maintain the vinyl chloride monomer in the liquid phase and to control the reaction rate- In some cases, a chain transfer agent may be added to control the molecular weight of the resulting PVC polymerAfter the polymerization reaction is complete, the resulting PVC polymer is isolated, purified, and dried before being processed into various products.