A 1D model for polymer melting during modulated temperature differential scanning calorimetry

摘要

A 1D model for the melting of polymers, assuming the polymer crystals take the form of lamellæ or thin sheets of material, is discussed. The model is derived on the assumption that the melting point of a lamella depends upon its thickness, that a lamella melts the instant this temperature is exceeded and that lamellæ with higher melting points grow by accumulating surplus of melt. The model is analysed for a temperature control that is the sum of a linear and a sinusoidal function of time as in modulated temperature differential scanning calorimetry, which is a technique for measuring thermal properties of materials. This work is an extension of a previous paper, by the same authors, considering a homogeneous model, based on the same assumptions. Some predictions regarding the output of such calorimetry are made.