Conformational reorganization viewed by the raman spectrum of aromatic polyesters

Abstract
Analysis is made of the asymmetry of the carbonyl stretching vibration of poly(ethylene terephthalate) and poly(propylene terephthalate) as a function of annealing frrom amorphous to crystalline polymer. An apparently anomalous behavior of carbonyl band half‐width as a function of density for PPT is shown to be due to this asymmetry. The results are interpreted in terms of the conformational redistribution which occurs upon annealing.