Temperature dependence of the melting enthalpy

This study addresses the question of the crys- tallinity determination of PA6 by means of DSC in the case when structural changes occur over a very large tem- perature domain during the heating scan. The temperature dependence of the melting enthalpy is then of crucial im- portance for determining the amount of crystalline phase involved in the various processes, and thus the initial crystallinity. Both DSC and WAXS measurements have been carried out of a PA6 sample submitted to various thermal treatments in order to identify the crystalline forms and the temperature-induced structural changes. The melting enthalpy dependence on temperature of PA6 was computed from heat capacity data of the solid and liquid borrowed from literature data tables. Similar computations were performed for PA66 which is likely to exhibit ana- logous structural changes during DSC analysis.