Frequency dependence of the dynamic heat capacity at the melting temperature of polyethylene crystals

The dynamic heat capacity of polyethylene was measured in the heating proce ss over two decades of the modulating frequency using the light heating mod ulated temperature DSC. The dynamic heat capacity exhibited clear frequency dependence from 95 degrees C to the end of the melting of the crystals. Fr equency dependence of this work was compared with that of the quasi-isother mal measurement. The relaxation time estimated in this work was much shorte r than that of the quasi-isothermal measurement. It was found that notable heat exchange between the sample and reference sides occurred between 120 a nd 135 degrees C. Frequency dependence of the heat exchange was studied.