Studies on several mixtures of PEG based phase change materials for heat transfer Applications: An experimental approach

• New PEG 400 + PEG 200 mixtures were manufactured. • DSC, TG and DTG analysis were performed for all the fluids. • Thermal conductivity and isobaric heat capacity were experimentally determined. • Thermal stability and thermophysical properties of all mixtures and pure fluids were debated comparatively. This article discusses the properties of two polyethylene glycols (i.e. PEG 400 and PEG 200) together with several mixtures and their appropriateness as heat transfer fluids. The idea of the research stands on this research group previous studies on PEG 400 as heat transfer fluid and PEG 200 as a possible candidate for heat exchange processes. As far as these authors are aware, this approach of mixing PEGs for creating an improved heat transfer fluid is a complete novelty. The study compares the properties of six fluids in terms of differential thermal analysis, thermogravimetry, derivative thermogravimetry and differential scanning calorimetry. Plus, the thermal conductivity and the isobaric heat capacity were experimentally measured, while viscosity was estimated as an indication for the change in thermal transport. Experimental data were analyzed comparatively and were discussed in the context of the state of the art. Results indicated that mixtures between PEG 400 and PEG 200 can be a viable solution for heat transfer fluids, combining the advantages of the two polyethylene glycols and minimizing each PEG drawbacks.