Comparative X-ray analysis of the crystalline structure of polyglycolide and polycondensate of sodium monochloroacetate

he crystalline structures of two aliphatic polyesters with identical chemical structures were examined by means of X-ray analysis. Polyesters were prepared by cationic polymerization of glycolide and by polycondensation of sodium salt of monochloracetic acid. The principal parameters of the crystalline structure (interplanar distances) in both polyesters were shown to coincide. In the polycondensation polymer, the crystallites of highly disperse sodium chloride were shown to produce an individual phase (∼ 50 wt %). In this polymer, the end groups of macromolecules containing sodium and chlorine atoms should concentrate, with high probability, in the amorphous regions of polymer. In this case, sodium chloride performs as a filler.