A 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 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 new experimental technique for measuring thermal properties of materials. Some predictions regarding the output of such calorimetry for polymer melting are made.
- Differential scanning calorimetry
- Polymer melting