The most effective reaction conditions for the synthesis of high molecular weight polyvinyl alcohol PVA from vinyl acetate monomer VAM involve a two-step process: the polymerization of VAM to polyvinyl acetate PVAc and the hydrolysis of PVAc to PVA.1. Polymerization of VAM to PVAc:- Temperature: The optimal temperature range for this reaction is between 50-70C.- Pressure: The reaction is typically carried out under atmospheric pressure.- Catalyst: Free-radical initiators, such as azobisisobutyronitrile AIBN or benzoyl peroxide, are used as catalysts for this reaction. The concentration of the initiator should be around 0.1-1.0 mol% relative to the VAM.- Solvent: The reaction can be performed in bulk or in a solvent, such as methanol or water, to control the molecular weight and dispersity of the resulting polymer.2. Hydrolysis of PVAc to PVA:- Temperature: The optimal temperature range for this reaction is between 60-90C.- Pressure: The reaction is typically carried out under atmospheric pressure.- Catalyst: Alkaline catalysts, such as sodium hydroxide NaOH or potassium hydroxide KOH , are used for the hydrolysis reaction. The concentration of the catalyst should be around 1-5 mol% relative to the PVAc.- Solvent: The reaction is usually performed in water, as it is the most suitable solvent for the hydrolysis of PVAc to PVA.To obtain high molecular weight PVA, it is essential to control the reaction conditions, such as temperature, catalyst concentration, and reaction time, to achieve a high degree of polymerization and hydrolysis. Additionally, the choice of initiator and catalyst, as well as the solvent, can significantly influence the molecular weight and properties of the resulting PVA.