Polyvinyl Alcohol - China

Brief Overview
Polyvinyl alcohols, also known as Polyethanol or PVA, are polymers from its monomer vinyl alcohol. Polyvinyl alcohol is physically odorless and tasteless, translucent, non- toxic, white or cream colored granular powder. The specific functional and physical characteristics of polyvinyl alcohol will depend on the degree of hydrolysis and the degree of polymerization. Because of that, polyvinyl alcohol is classified into two classes namely: partially hydrolyzed and fully hydrolyzed. Partially hydrolyzed PVA is usually applied in the food industry.

Manufacturing Process
The primary raw material used in the manufacture of polyvinyl alcohol is a vinyl acetate monomer. It is manufactured by the polymerization of vinyl acetate followed by partial hydrolysis. The process of hydrolysis is based on the partial replacement of the ester group in vinyl acetate with the hydroxyl group and is completed in the presence of aqueous sodium hydroxide. Following gradual addition of the aqueous saponification agent. Polyvinyl alcohol is precipitated, washed, and dried. The degree of hydrolysis is determined by the time point at which the saponification reaction is stopped.