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

The thermal conductivities of neopentylglycol (NPG), 1,1,1-trihydroxymethyl propane (TMP), and their mixture (NPG + TMP, mole ratio 50:50) were measure d in the temperature range from 20 degreesC to their supermelting temperatu res, by means of a calorimeter equipped with a thermistor. The principles o f the calorimetry and the calibration of the calorimeter were described in detail. The solid-solid transition and melting temperatures were found to b e 40 degreesC and 133 degreesC for NPG and 40 degreesC and 120 degreesC for (NPG + TMP), and a melting temperature of 60 degreesC was found for TMP. T he measured thermal conductivities of these substances were fitted in the t emperature range from 20 degreesC to their supermelting temperatures to obt ain 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.