On the solid-liquid equilibrium of binary mixtures of fatty alcohols and fatty acids

Autor(es)

Maximo, Guilherme J. ^[1] ; Carareto, Natalia D. D. ^[1] ; Costa, Mariana C. ^[2] ; dos Santos, Adenilson O. ^[3] ; Cardoso, Lisandro P. ^[4] ; Kraehenbahl, Maria A. ^[5] ; Meirelles, Antonio J. A. ^[1]

Afiliação do(s) autor(es)

^[1] Univ Estadual Campinas, UNICAMP, Sch Food Engn, Lab Extract Appl Thermodynam & Equilibrium, BR-13083862 Campinas, SP - Brazil

^[2] Univ Estadual Campinas, Sch Appl Sci, BR-13484350 Limeira, SP - Brazil

^[3] Univ Maranhao, Social Sci Hlth & Technol Ctr, BR-65900410 Imperatriz, Maranhao - Brazil

^[4] Univ Estadual Campinas, Inst Phys Gleb Wataghin IFGW, BR-13083859 Campinas, SP - Brazil

^[5] Univ Estadual Campinas, Sch Chem Engn, DDPP, BR-13083970 Campinas, SP - Brazil

• Tipo de documento: Artigo Científico
• Fonte: Fluid Phase Equilibria; v. 366, p. 88-98, MAR 25 2014.
• Citações Web of Science: 29

Resumo

Fatty alcohols and fatty acids are used in the cosmetic, pharmaceutical and food industries as surfactants. They are also considered phase change materials for thermal storage processes. Information on their thermal properties is required for optimizing production processes as well as for improving their industrial and home use. In the present study, the solid-liquid phase diagrams of three binary systems of 1-tetradecanol + dodecanoic acid, 1-hexadecanol + tetradecanoic acid and 1-octadecanol + hexadecanoic acid were determined by differential scanning calorimetry. The phase-transition phenomena were further investigated by optical micrographs and X-ray diffraction patterns. The experimental data showed that the systems present eutectic transitions and some of them exhibit partial solid phase miscibility. The liquid phase activity coefficients were calculated by Margules 2 and 3-suffix and by UNIFAC and UNIFAC-Dortmund methods. The modeling approach resulted in an accurate prediction, with average absolute deviations from experimental data lower than 1.16 K. The values of excess Gibbs free energy present an unusual behavior, with positive deviations at very low alcohol concentrations and negative ones at high concentrations of this component. This occurs due to changes in the H-bonding interactions along the concentration range of the mixture. (C) 2014 Elsevier B.V. All rights reserved. (AU)

• Processo FAPESP: 09/54137-1 - EMUS: aquisição de um analisador de distribuição de tamanho de partículas, um medidor de potencial zeta, um spray dryer e um sistema de cromatografia líquida de ultra alta pressão / espectrômetro de massa
• Beneficiário: Miriam Dupas Hubinger
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• Processo FAPESP: 12/05027-1 - Equilíbrio sólido-líquido de compostos graxos e ponto de fulgor de biodiesel
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• Processo FAPESP: 08/56258-8 - Phase equilibrium and purification processes in the production of biofuels and biocompounds
• Beneficiário: Antonio José de Almeida Meirelles
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