The Effects of Partial Acetylation on the Mechanical Properties of Poly(vinyl alcohol)

Abstract

The mechanical properties of partially acetylated poly (vinyl alcohol) were studied by dynamic measurements over a wide temperature range. After partial acetylation, the αc-loss peak disappeared and the βc-, αa-, and βa-loss peaks shifted to lower temperatures and showed an increase in their peak heights. The αc-loss peak of the highly acetylated samples merged into the αa-loss peak. There was also a linear relation between the density and the temperature of the βa-loss peak for the partially acetylated samples. These results are discussed in terms of the disordering of the crystalline structure, breakdown of the hydrogen bonds, and increase in the local mobility of the chain segments by partial acetylation.