Polyhydroxyethers. III. Ester derivatives

The esterification of high molecular weight hydroxyether polymers, derived from dihydric phenols and epichlorohydrin, has been studied. The esters of an assortment of monobasic acids, both organic and inorganic, were prepared by reaction of acid halides, anhydrides, esters or free acids with the secondary hydroxyl group in the polymer repeating unit. The effects of the structure of the acid radical and the degree of esterification on polymer properties were determined. In general, esterification resulted in a lowering of the major glass transition temperature of the polymer. This was true at all levels of esterification. Decreased chain symmetry and decreased hydrogen bonding appeared to be the major causes of the observed effect. Permeability of the polymers to oxygen and water vapor was increased by esterification. The increases was found to correlate well with the size and polarity of the acid radical. Some additional properties of the ester derivatives were examined in less detail.