An approximative method for the evaluation of the partial heats of fusion of the once folded and extended modification of poly(ethylene oxide) 6000

Abstract PEG 6000 can exist in an once folded and in an extended modification. The small difference in the melting temperatures of the two forms results in a significant overlap of the corresponding melting peaks. After completion of the phase transition the shape of a melting peak (second branch) registered by DSC is determined by the relaxation of the measuring system only. Therefore it is possible to separate overlapping melting peaks by means of the standardised relaxation function of the DSC system. This approach was used to separate the overlapping melting peaks of the two PEG modifications. The partial heats of fusion as well as the peak maxima characterising the individual melting processes were determined from the separated peaks. Furthermore, this technique enables an observation of changes in the modifications of PEG and could possibly be a useful tool for investigations of other polymers which show similar characteristics.