Acetals, such as polyvinyl butyral, are formed by the
well-known reaction between aldehydes and alcohols.The
addition of one molecule of an alcohol to one molecule of
an aldehyde produces a hemiacetal. Hemiacetals are rarely
isolated because of their inherent instability but, rather, are
further reacted with another molecule of alcohol to form a
stable acetal.
Polyvinyl acetals are prepared from aldehydes and polyvinyl
alcohols. Polyvinyl alcohols are high molecular weight resins
containing various percentages of hydroxyl and acetate
groups produced by hydrolysis of polyvinyl acetate