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

PEG 6000 can exist in an once folded and in an extended modification. The s mall difference in the melting temperatures of the two forms results in a s ignificant 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. There fore it is possible to separate overlapping melting peaks by means of the s tandardised relaxation function of the DSC system. This approach was used t o separate the overlapping melting peaks of the two PEG modifications. The partial heats of fusion as well as the peak maxima characterising the indiv idual melting processes were determined from the separated peaks. Furthermo re, this technique enables an observation of changes in the modifications o f PEG and could possibly be a useful tool for investigations of other polym ers which show similar characteristics. (C) 2000 Elsevier Science B.V. All rights reserved.