Sugar alcohols and other organic compounds as phase change materials

Abstract

The objective of this thesis was the synthesis and modification of novel phase-change materials (PCMs) which are able to absorb a high amount of energy at the time of melting and release it upon recrystallization. Organic compounds as PCMs are very interesting as a result of their high storage capacity, safety and low cost. Additionally, they are able to cover an interesting range of melting temperatures. There is a large number of PCMs that change their phase in a range of 80 oC to 200 oC. Thus, the use of latent heat storage systems using organic PCMs has a promising future for industrial applications at medium temperatures. It was possible to obtain better organic materials for thermal storage devices and improve their melting energy and thermal stability among other properties by studying and comparing their structures and identifying trends. This resulted in an efficient design of a new class of organic Phase-change materials (PCMs) which are able to store up to 375.6 kJ/kg in the predefined temperature range of 80 °C to 200 °C. Beyond their relatively high storage capacity, these materials display advantages regarding safety and low-cost production. Within this thesis, the melting enthalpy and melting temperature for different groups of organic PCMs was compared based on their structure. Additionally, DSC measurements combined with thermal stability TGA analysis of these compounds was carried out.