MEASUREMENTS OF THE THERMAL CONDUCTIVITY OF ORGANIC POLYMERS BY THE TRANSIENT HOT-STRIP METHOD
The transient, hot-strip method is applied to materials having a low thermal conductivity. In this procedure, the resistance vs time curve is measured of a strip that is embedded in the sample material and heated by an electric current. A function containing the conductivity as an adjustable parameter is fitted to the measured curve. Due to thermal conduction within the strip, the function as derived by Gustafsson must he modified for measurements with low-conductivity samples. A modified function was calculated numerically for a single, but convenient strip geometry. The strip resistance is measured in such a way that complications due to the temperature drop at the ends of the strip arc avoided. The measurements also yield the specific heat capacity, which is in good agreement with results obtained by differential scanning calorimetry.