Synthesis and Characterization of Fatty Acid Amides from Commercial Vegetable Oils and Primary Alkyl Amines for Phase Change Material Applications

The feasibility of synthesizing bio-based fatty acid amides for phase change material (PCM) applications was studied. Fatty acid amides (FAAms) were successfully synthesized from commercial vegetable oils and primary alkyl amines. The chemical structures of the samples were characterized through FTIR, 1 H-NMR, and 13 C-NMR, while their thermal properties were studied using DSC and TGA. Results show the potential of FAAms synthesized from corn and sunflower oils to be used as PCMs, which exhibited single transitions over narrow temperature ranges upon cooling/heating even when no fractionation or separation of the material was carried out. The melting temperature of the FAAms increased with the length of the precursor amine, and a similar trend was observed for latent heat except for FAAms from hexadecylamine. Latent heats of the synthesized materials were as high as 141 kJ/kg, and all the FAAms were thermally stable under 200 °C.