Chapter 26, Problem 26.60P

Interpretation Introduction

Interpretation:

$\text{Poly}\left(\text{vinyl alcohol}\right)\text{, PVA}$, is produced from $\text{poly}\left(\text{vinyl acetate}\right)$ by converting the acetate groups into hydroxyl groups ($\text{Section 26}\text{.6a}\text{.1}$). As the number of hydroxyl groups in $\text{PVA}$ increases, the solubility of the polymer in water decreases. The reason for this behavior is to be explained.

Concept introduction:

When the intermolecular interactions involving the solvent molecules are similar to those involving the polymer molecules, the polymer tends to dissolve. Non polar aromatic polymers dissolve in a nonpolar aromatic solvent. A polymer with OH group dissolves in water because its hydroxyl groups can form hydrogen bond with water. Polymers with ionic side groups dissolve even more readily in water due to ion-dipole interactions. Any factors that limit the interactions between the solvent molecules and polymer will decrease solubility.