Measurement of the thermal conductivities of neopentylglycol, 1,1,1-trihydroxymethylpropane, and their mixture in the temperature range from 20 °C to their supermelting temperatures

The thermal conductivities of neopentylglycol (NPG), 1,1,1-trihydroxymethylpropane (TMP), and their mixture (NPG + TMP, mole ratio 50:50) were measured in the temperature range from 20 °C to their supermelting temperatures, by means of a calorimeter equipped with a thermistor. The principles of the calorimetry and the calibration of the calorimeter were described in detail. The solid-solid transition and melting temperatures were found to be 40 °C and 133 °C for NPG and 40 °C and 120 °C for (NPG + TMP), and a melting temperature of 60 °C was found for TMP. The measured thermal conductivities of these substances were fitted in the temperature range from 20 °C to their supermelting temperatures to obtain the smoothed best-fit values. The uncertainties of the measured thermal conductivities were evaluated to be ±3.5, ±2.1, and ±2.4% for NPG, TMP, and (NPG + TMP), respectively.