Hexamethylene dilauroyl, dimyristoyl, and dipalmytoyl amides as phase change materials for thermal energy storage

Hexamethylene dilauroyl, dimyristoyl, and dipalmytoyl amides have been produced as solid liquid phase change materials via condensation of hexamethylene diamine with the respective acyl chlorides (lauroyl chloride, myristoyl chloride, and palmytoyl chloride) and were characterized by FT-IR, NMR, DSC, and TG analysis. Hexamethylene dilauroyl, dimyristoyl, and dipalmytoyl amides crystallized due to structural symmetry and flexibility of long alkyl groups. They were characterized by DSC and FT-IR spectroscopy before and after thermal cycling to determine their thermal reliability. Phase change enthalpies were found 110.1 and -103.3 J g(-1) for hexamethylene dilauroyl amide (N,N'-hexamethylene didodecanamide), 116.9 and -110.4 J g for hexamethylene dimyristoyl amide (N,N'-hexamethylene ditetradecanamide), and 144.5 and -140.5 J g(-1) for hexamethylene dipalmytoyl amides (N,N'-hexamethylene dihexadecanamide) by DSC. The endurance of hexamethylene dilauroyl, dimyristoyl, and dipalmytoyl amides was studied by TG analysis. (C) 2010 Elsevier Ltd. All rights reserved.