The hot wire parallel technique standardized for determining thermal conductivity of ceramic materials was employed in the determination of thermal properties of polymers. Samples were prepared in shape of rectangular parallelepipeds. In this work the thermal conductivity and the specific heat were simultaneously determined from the same experimental thermal transient, and the thermal diffusivity is derived from these properties. Five different polymers with different structures at room temperature were selected and measurements were carried out at room temperature. A non-linear least squares fitting method was employed in the calculations, so that all the experimental points obtained are considered in the thermal properties calculations. The apparatus used in this work is fully automatic. The reproducibility is very good with respect to thermal conductivity, even with a defective experimental arrangement with respect to the theoretical model. However, deviations from the theoretical model causes severe influence on the specific heat values and consequently in the thermal diffusivity. Experimental results were compared with those available in literature, showing the applicability of this technique in the determination of thermal properties of polymers.
Polymer; thermal conductivity; specific heat; thermal diffusivity; thermal properties; hot wire technique
