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ISSN Online: 2377-424X

International Heat Transfer Conference 12
August, 18-23, 2002, Grenoble, France

Transient Cooling Analysis Of Semi-Crystalline Polymers

Get access (open in a dialog) DOI: 10.1615/IHTC12.2160
6 pages

Resumo

The paper presents a mathematical model, solved with a numerical finite-difference implicit scheme, used to analyze the effects of local thermal history on the crystallization process of semi-crystalline polymers during cooling and transient solidification. The simple models of Avrami-Kolmogoroff-Evans, able to quantitatively describe the progress of crystallisation in isothermal conditions, are properly embedded in the heat transfer equations and used to calculate the crystallization rate in actual thermal transients. Temperature and absolutecrystallinity-degree dependent thermophysical properties are considered. The possibility to use such an approach in a transient, strongly non-isothermal field is proved by comparing numerical data to literature-available experimental results, related to polyethylene oxide samples. Proper actual values of four empirical constants are calculated in order to minimise the mean square errors between experimental and theoretical data. To simulate correctly the polymer crystallisation behaviour in non-isothermal experiments, the thermal effects of the confining material are taken into account. The effects of the rate of imposed transient cooling on temperature profiles and crystallization process in the sample bulk are outlined.