The most efficient and economical method for synthesizing polyvinyl alcohol PVA from vinyl acetate monomer VAM is through a two-step process: polymerization of VAM to polyvinyl acetate PVAc followed by hydrolysis of PVAc to PVA.1. Polymerization of VAM to PVAc: The most common and efficient method for this step is the free radical polymerization process. This can be carried out using either a batch, semi-batch, or continuous process. The choice of process depends on the desired molecular weight and polydispersity of the resulting PVAc. Initiators, such as azo compounds or peroxides, are used to generate free radicals that initiate the polymerization reaction. The reaction is typically carried out in a solvent, such as water or an organic solvent, at temperatures between 50-80C.2. Hydrolysis of PVAc to PVA: The second step involves the hydrolysis of PVAc to PVA, which can be achieved using either an acidic or alkaline catalyst. The most common and economical method is alkaline hydrolysis using sodium hydroxide NaOH or potassium hydroxide KOH as the catalyst. The degree of hydrolysis can be controlled by adjusting the concentration of the catalyst and the reaction time. The reaction is typically carried out at temperatures between 60-90C.The purity, yield, and properties of the resulting PVA depend on the choice of polymerization and hydrolysis conditions, as well as the purification steps employed after each reaction. To obtain high-purity PVA, it is essential to remove any residual monomer, catalyst, and by-products. This can be achieved through techniques such as precipitation, filtration, and washing.In summary, the most efficient and economical method for synthesizing PVA from VAM is the two-step process involving free radical polymerization of VAM to PVAc and alkaline hydrolysis of PVAc to PVA. The choice of reaction conditions and purification steps will determine the purity, yield, and properties of the resulting PVA.