Estimation of thermal endurance of multicomponent sugar alcohols as phase change materials

This study investigates the thermal endurance of sugar alcohols and their eutectic mixtures as phase-change materials (PCMs). Three sugar alcohols (mannitol, dulcitol, and inositol) and their eutectic mixtures were selected as the PCM candidates. First, the thermophysical properties of the single- and multicomponent sugar alcohols were characterized using differential scanning calorimetry. Second, the thermal endurance of the PCM candidates was estimated by constant-temperature kinetics based on the degradation of the latent heat of the PCM candidates. The results showed that mannitol, dulcitol, inositol, and their eutectic mixtures had melting points and latent heats of over 423 K and 200 kJ/kg, respectively. The kinetic analysis of the PCM candidates showed that the first-order reaction rate equation was suitable for analyzing the degradation of the latent heat of the sugar alcohols. The degradation periods increased with decrease of melting temperatures of each sugar alcohol. In particular, the dulcitol/mannitol eutectic mixture showed the longest degradation periods of 9817 ks, which is 5.68 and 6.85 times greater than those of pure mannitol and dulcitol, respectively. These observations indicated that eutectic mixtures of sugar alcohols were promising and alternative PCM candidates in the 373–473 K temperature range.