The synthesis of polyvinyl alcohol PVA from vinyl acetate monomer VAM involves a two-step process: the polymerization of VAM to polyvinyl acetate PVAc and the hydrolysis of PVAc to PVA.1. Polymerization of Vinyl Acetate Monomer VAM to Polyvinyl Acetate PVAc :Solvent: The reaction can be carried out in bulk no solvent or in a solvent like methanol, ethanol, or water. The choice of solvent depends on the desired properties of the final PVA product and the ease of processing.Catalyst: Free-radical initiators like azobisisobutyronitrile AIBN or benzoyl peroxide BPO are commonly used as catalysts for the polymerization of VAM. The concentration of the initiator is typically in the range of 0.1-1 wt% based on the VAM.Temperature: The polymerization temperature depends on the initiator used. For AIBN, the temperature is usually around 60-70C, while for BPO, it is around 80-90C.Time: The reaction time depends on the desired molecular weight of the PVAc and the reaction conditions. Generally, the reaction is allowed to proceed for several hours to achieve a high conversion of VAM to PVAc.2. Hydrolysis of Polyvinyl Acetate PVAc to Polyvinyl Alcohol PVA :Solvent: Water is used as the solvent for the hydrolysis reaction.Catalyst: An alkaline catalyst, such as sodium hydroxide NaOH or potassium hydroxide KOH , is used for the hydrolysis of PVAc. The concentration of the catalyst is typically in the range of 1-5 wt% based on the PVAc.Temperature: The hydrolysis reaction is usually carried out at an elevated temperature, typically in the range of 60-90C, to accelerate the reaction rate.Time: The reaction time depends on the desired degree of hydrolysis and the reaction conditions. Generally, the hydrolysis reaction is allowed to proceed for several hours to achieve a high degree of hydrolysis above 90% .In summary, the optimal reaction conditions for synthesizing PVA from VAM include:1. Polymerization of VAM to PVAc: - Solvent: Bulk or methanol, ethanol, or water - Catalyst: AIBN or BPO 0.1-1 wt% based on VAM - Temperature: 60-70C AIBN or 80-90C BPO - Time: Several hours2. Hydrolysis of PVAc to PVA: - Solvent: Water - Catalyst: NaOH or KOH 1-5 wt% based on PVAc - Temperature: 60-90C - Time: Several hours