Thermal Properties and Reliabilities of Lauric Acid-Based Binary Eutectic Fatty Acid as a Phase Change Material for Building Energy Conservation

Abstract

Thermal properties, stability, and reliability of lauric acid-based binary eutectic mixtures for building energy efficiency were studied. The eutectic points and phase change performance of these binary PCMs were obtained as follows: (1) For lauric acid–myristic acid, the mass eutectic point is 70 wt % LA/30 wt % MA. (2) For lauric acid–palmitic acid, the eutectic point is 79 wt % LA/21 wt % PA. (3) For lauric acid–stearic acid, the eutectic point is 82 wt % LA/18 wt % SA. The eutectic PCMs have a melting enthalpy of 166.18, 183.07, and 189.50 J·g –1 and a melting temperature of 35.10, 37.15, and 39.29 °C for lauric–myristic acid, lauric–palmitic acid, and lauric–stearic acid binary eutectic PCMs, respectively. The experimental results are very close to the theoretical results. Moreover, from FT-IR and XRD investigations, we realized that during the preparation of the lauric acid-based binary eutectic fatty acids, no new functional groups were produced. Besides, the TG illustrated that the LA–MA eutectic PCMs, LA–PA eutectic PCMs, and LA–SA eutectic PCMs exhibit excellent thermal stability below 126.51, 135.7, and 110.08 °C, respectively. Finally, lauric acid-based binary eutectic PCMs still show excellent thermal properties and chemical structure after 500 hot and cold cycles. All in all, as a novel material for building energy conservation, lauric acid-based binary eutectic PCMs have broad prospects and good practicability.

Preparation and characterization of lauric acid–stearic acid/expanded perlite as a composite phase change material

“…In our previous study, the eutectic mass ratio of L–S was determined to be 82 : 18 by step-cooling curve experiments and DSC analysis. 32 The LS/EP CPCMs were synthesized using the vacuum impregnation process shown in Fig. 1 .…”

Study on the Reliability and Stability of Fatty Acid‐Paraffin Ternary Phase Change Materials as Energy‐saving Materials

“…After analysing them through various tests it was concluded that both PCMs were suitable for self-compacting concrete mixtures used in buildings. Dai et al [27] prepared composite PCMs with good properties and suitable phase change temperatures by combining different fatty acids. They found that multiple PCMs can indeed extend the phase change temperature range.…”

A ultra‐low viscosity stearic acid emulsion prepared by lauric acid as waterproof agent for cement mortar

“…[34][35][36] Through eutectic behavior, it is possible to modify the crystallization temperature, particulate size, and enthalpy of binary or tribasic fatty acid complex systems. 35,37 Lauric acid is a type of "reactive emulsifier," because it could undergo a chelation reaction with calcium ions in cement due to its carboxylic acid groups. [38][39][40] The use of reactive emulsifier lauric acid for the preparation of low-viscosity stearic acid emulsion not only solves the problem of inadequate dispersion of stearic acid powder in cement, but also solves the problem of water absorption of residual emulsifier in mortar.…”

“…The fatty acids lauric acid, palmitic acid, and oleic acid exhibit eutectic behavior with stearic acid during melt merging, according to studies 34–36 . Through eutectic behavior, it is possible to modify the crystallization temperature, particulate size, and enthalpy of binary or tribasic fatty acid complex systems 35,37 . Lauric acid is a type of “reactive emulsifier,” because it could undergo a chelation reaction with calcium ions in cement due to its carboxylic acid groups 38–40 .…”