A correction function to determine the beta-fusion heat in a mixture of alpha- and beta-PP

Blends of known amounts of alpha- and beta -PP crystals were prepared from pure alpha- and pure beta -PP samples. Their fusion behaviours were studied by differential scanning calorimetry (DSC). The fusion heats of the alpha- and beta -crystals were approximated from the DSC curves and compared with those calculated on the basis of the compositions of the blends. A correction function was found which improved the accuracy of the respective fusion heats significantly from the DSC analysis. The correction function can be used to determine the respective fusion heats of a PP sample which contains an unknown mixture of the alpha- and beta -crystals.