Encapsulated Fatty Acids in an Acrylic Resin as Shape-stabilized Phase Change Materials for Latent Heat Thermal Energy Storage

Abstract

This article aims to prepare novel shape-stabilized phase change materials (PCMs) by encapsulating fatty acids (stearic acid [SA], palmitic acid [PA], and myristic acid [MA]) as a PCM in an acrylic resin (Eudragit E) as supporting material and to determine latent heat thermal energy storage (LHTES) properties. The maximum percentage of all fatty acids in the shape-stabilized PCMs was found to be 70 wt% in which no fatty acid seepage was observed as the blends were heated over the melting points of the fatty acids. The optic microscope (OM) investigation demonstrated that fatty acid domains were coated by Eudragit E. Fourier transform infrared (FT-IR) results revealed that the interactions between Eudragit E and fatty acids were only adequate for adhesion of Eudragit E on fatty acid domains. Single phase was observed for the blends by OM, and interactions between the components were investigated by FT-IR spectroscopy. The melting and freezing temperatures and latent heats of the shape-stabilized PCMs were measured by the differential scanning calorimetry (DSC) method. Based on the results, it was concluded that Eudragit E/MA, Eudragit E/PA, and Eudragit E/SA blends (30/70 wt%) have good utility potential for LHTES purposes in terms of their satisfying thermal properties and advantages of easy preparation in desired dimensions, direct usefulness function in LHTES systems, and cost effectiveness.

Keywords:

• differential scanning calorimetry (DSC)
• Eudragit E
• fatty acids
• FT-IR
• thermal properties

Acknowledgment

The authors would like to acknowledge the financial support (Project No. 2003K120510) by the Turkish State Planning Organization.