Journal of the American Oil Chemists' Society

, Volume 86, Issue 9, pp 843–856 | Cite as

A Comprehensive Evaluation of the Melting Points of Fatty Acids and Esters Determined by Differential Scanning Calorimetry

Original Paper

Abstract

The melting point is one of the most important physical properties of a chemical compound and it plays a significant role in determining possible applications. For fatty acid esters the melting point is essential for a variety of food and non-food applications, the latter including biodiesel and its cold-flow properties. In this work, the melting points of fatty acids and esters (methyl, ethyl, propyl, butyl) in the C8–C24 range were determined by differential scanning calorimetry (DSC), many of which for the first time. Data for triacylglycerols as well as ricinoleic acid and its methyl and ethyl esters were also acquired. For some compounds whose melting points have been previously reported, data discrepancies exist and a comprehensive determination by DSC has not been available. Variations in the present data up to several °C compared to data in prior literature were observed. The melting points of some methyl-branched iso- and anteiso-acids and esters were also determined. Previously unreported systematic effects of compound structure on melting point are presented, including those for ω-9 monounsaturated fatty acids and esters as well as for methyl-branched iso and anteiso fatty acids and esters. The melting point of a pure fatty acid or ester as determined by DSC can vary up to approximately 1 °C. Other thermal data, including heat flow and melting onset temperatures are briefly discussed.

Keywords

Fatty acids Differential scanning calorimetry Butyl esters Ethyl esters Melting point Methyl esters Propyl esters 

References

  1. 1.
    Weast RC (1985) Handbook of chemistry and physics, 66th edn. CRC Press, Boca RatonGoogle Scholar
  2. 2.
    Lide DR (1999) Handbook of chemistry and physics, 80th edn. CRC Press, Boca RatonGoogle Scholar
  3. 3.
    Lide DR (2007) Handbook of chemistry and physics, 88th edn. CRC Press, Boca Raton, FLGoogle Scholar
  4. 4.
    Gunstone FD, Harwood JL, Dijkstra AJ (eds) (2007) The lipid handbook, 3rd edn. CRC Press, Boca RatonGoogle Scholar
  5. 5.
    Doss MP (1952) Properties of the principal fats, fatty oils, waxes, fatty acids and their salts. Texas, New YorkGoogle Scholar
  6. 6.
    Gunstone FD, Ismail IA (1967) Fatty acids part 14. The conversion of the cis octadecenoic acids to their trans isomers. Chem Phys Lipids 1:264–269CrossRefGoogle Scholar
  7. 7.
    Schlenk W Jr (1969) Long-chain carboxylic esters: melting points, rules for occurrence of vertical type crystals, and atomic distances in long spacings (Langkettige Carbonsäureester: Schmelzpunkte, Regeln für das Auftreten des Vertikaltyps der Kristallstruktur, Inkremente des grossen Netzebenenabstandes). Liebigs Ann Chem 727:1–9CrossRefGoogle Scholar
  8. 8.
    Barve JA, Gunstone FD (1971) Fatty acids, part 33. The synthesis of all the octadecynoic acids and all the trans-octadecenoic acids. Chem Phys Lipids 7:311–323CrossRefGoogle Scholar
  9. 9.
    Marosi L, Schlenk W Jr (1973) Melting points in homologous series of long-chain compounds (Schmelzpunkte in einigen homologen Reihen langkettiger Verbindungen). Liebigs Ann Chem 4:584–598Google Scholar
  10. 10.
    Jalal IM, Zografi G, Rakshit AK, Gunstone FD (1982) Thermal analysis of fatty acids. Chem Phys Lipids 31:395–404CrossRefGoogle Scholar
  11. 11.
    Dadarlat D, Bicanic D, Gibkes J, Kloek W, van den Dries I, Gerkema E (1996) Study of melting processes in fatty acids and oil mixtures: a comparison of photopyroelectric (PPE) and differential scanning calorimetry (DSC). Chem Phys Lipids 82:15–23CrossRefGoogle Scholar
  12. 12.
    Levene PA, West CJ (1914) Purification and melting points of saturated aliphatic acids. J Biol Chem 18:463–467Google Scholar
  13. 13.
    Howton DR (1970) Empirical melting point-structure relationships in the normal acetylenic carboxylic acids. J Chem Soc B 18:4–188Google Scholar
  14. 14.
    Gunstone FD, Jacobsberg FR (1972) Fatty acids, part 35. The preparation and properties of the complete series of methyl epoxyoctadecanoates. Chem Phys Lipids 9:26–34CrossRefGoogle Scholar
  15. 15.
    Weitzel G, Wojahn J (1951) Biochemical branched-chain carboxylic acids. VI. Preparation of the racemic monomethylstearic acids. Hoppe-Seyler’s Z Physiol Chem 287:296–310Google Scholar
  16. 16.
    Seher A (1956) Synthesis and properties of vinyl fatty acids. (Synthese und Eigenschaften von Vinyl-Fettsäuren). Fette Seifen Anstrichmittel 58:1077–1080CrossRefGoogle Scholar
  17. 17.
    Iyengar BTR, Schlenk H (1969) Melting points of synthetic wax esters. Lipids 4:28–30CrossRefGoogle Scholar
  18. 18.
    Yao L, Hammond EG (2006) Isolation and melting properties of branched-chain esters from lanolin. J Am Oil Chem Soc 83:547–552CrossRefGoogle Scholar
  19. 19.
    Yao L, Hammond E, Wang T (2008) Melting points and viscosities of fatty acid esters that are potential targets for engineered oilseed. J Am Oil Chem Soc 85:77–82CrossRefGoogle Scholar
  20. 20.
    Knothe G, Van Gerpen J, Krahl J (eds) (2005) The biodiesel handbook. AOCS Press, ChampaignGoogle Scholar
  21. 21.
    Mittelbach M, Remschmidt C (2004) Biodiesel—the comprehensive handbook publ. M Mittelbach, GrazGoogle Scholar
  22. 22.
    Dunn RO, Bagby MO (1995) Low-temperature properties of triglyceride-based diesel fuels: transesterified methyl esters and petroleum middle distillate/ester blends. J Am Oil Chem Soc 72:895–904CrossRefGoogle Scholar
  23. 23.
    Dunn RO (1999) Thermal analysis of alternative diesel fuels from vegetable oils. J Am Oil Chem Soc 76:109–115CrossRefGoogle Scholar
  24. 24.
    Lee I, Johnson LA, Hammond EG (1995) Use of branched-chain esters to reduce the crystallization temperature of biodiesel. J Am Oil Chem Soc 72:1155–1160CrossRefGoogle Scholar
  25. 25.
    Foglia TA, Nelson LA, Dunn RO, Marmer WN (1997) Low-temperature properties of alkyl esters of tallow and grease. J Am Oil Chem Soc 74:951–955CrossRefGoogle Scholar
  26. 26.
    Wu W-H, Foglia TA, Marmer WN, Dunn RO, Goering CE, Briggs TE (1998) Low temperature property and engine performance evaluation of ethyl and isopropyl esters of tallow and grease. J Am Oil Chem Soc 75:1173–1178Google Scholar
  27. 27.
    Knothe G (2008) “Designer” biodiesel: optimizing fatty ester composition to improve fuel properties. Energy Fuels 22:1358–1364CrossRefGoogle Scholar
  28. 28.
    Warabi Y, Kusdiana D, Saka S (2004) Biodiesel from vegetable oil by various supercritical alcohols. Appl Biochem Biotechnol 113–116:793–801CrossRefGoogle Scholar
  29. 29.
    Zhang Y, Van Gerpen JH (1996) Combustion analysis of esters of soybean oil in a diesel engine. SAE Spec Publ SP-1160 (performance of alternative fuels for SI and CI engines). Society of Automotive Engineers, Warrendale, paper no. 960765Google Scholar
  30. 30.
    Lang X, Dalai AK, Bakhshi NN, Reaney MJ, Hertz PB (2001) Preparation and characterization of bio-diesels from various bio-oils. Bioresour Technol 80:53–62CrossRefGoogle Scholar
  31. 31.
    Knothe G, Bagby MO (1995) 13C NMR spectroscopy of unsaturated long chain compounds: an evaluation of the unsaturated carbon signals as rational functions. J Chem Soc Perkin Trans 2:615–620Google Scholar
  32. 32.
    American Oil Chemists’ Society, method Cj 1-94. AOCS, ChampaignGoogle Scholar
  33. 33.
    Cedeño FO, Prieto MM, Espina A, García JR (2001) Measurements of temperature and melting heat of some pure fatty acids and their binary and ternary mixtures by differential scanning calorimetry. Thermochim Acta 369:39–50CrossRefGoogle Scholar
  34. 34.
    Soriano NU Jr, Migo VP, Sato K, Matsumura M (2005) Crystallization behavior of neat biodiesel and biodiesel treated with ozonized vegetable oil. Eur J Lipid Sci Technol 107:689–695CrossRefGoogle Scholar
  35. 35.
    de Rodrigues JA Jr, de Cardoso FP, Lachter ER, Estevão LRM, Lima E, Nascimento RSV (2006) Correlating chemical structure and physical properties of vegetable oil esters. J Am Oil Chem Soc 83:353–357CrossRefGoogle Scholar
  36. 36.
    Imahara H, Minami E, Saka S (2006) Thermodynamic study on cloud point of biodiesel with its fatty acid composition. Fuel 85:1666–1670CrossRefGoogle Scholar
  37. 37.
    Dunn RO (2008) Crystallization behavior of fatty acid methyl esters. J Am Oil Chem Soc 85:961–972CrossRefGoogle Scholar
  38. 38.
    Knothe G, Steidley KR (2005) Kinematic viscosity of biodiesel fuel components and related compounds. Influence of compound structure and comparison to petrodiesel fuel components. Fuel 84:1059–1065CrossRefGoogle Scholar
  39. 39.
    Kotrba R (2006) Bound by determination. Biodiesel Mag 3:42–50Google Scholar
  40. 40.
    Van Gerpen JH, Hammond EG, Johnson LA, Marley SJ, Yu L, Lee I, Monyem A (1996) Determining the influence of contaminants on biodiesel properties. In: Report prepared for the Iowa Soybean Promotion Board. http://www.biodiesel.org/resources/reportsdatabase/reports/gen/19960731_gen014.pdf (accessed 11/21/2008)
  41. 41.
    Pfalzgraf L, Lee I, Foster J, Poppe G (2007) Effect of minor components in soy biodiesel on cloud point and filterability inform supplement no. 4: biorenewable resources. AOCS Press, Champaign, pp 17–21Google Scholar
  42. 42.
    Yu L, Lee I, Hammond EG, Johnson LA, Van Gerpen JH (1998) The influence of trace components on the melting point of methyl soyate. J Am Oil Chem Soc 75:1821–1824CrossRefGoogle Scholar
  43. 43.
    Lee I, Pfalzgraf LM, Poppe GB, Powers E, Haines T (2007) The role of sterol glucosides on filter plugging. Biodiesel Mag 4:105–112Google Scholar
  44. 44.
    Benjumea P, Agudelo J, Agudelo A (2008) Basic properties of palm oil based biodiesel–diesel blends. Fuel 87:2069–2073CrossRefGoogle Scholar
  45. 45.
    Rashid U, Anwar F (2008) Production of biodiesel through optimized alkaline-catalyzed transesterification of rapeseed oil. Fuel 87:265–273CrossRefGoogle Scholar
  46. 46.
    Lutton ES, Fehl AJ (1970) The polymorphism of odd and even saturated single acid triglycerides, C8–C22. Lipids 5:90–99CrossRefGoogle Scholar
  47. 47.
    Hagemann JW, Tallent WH, Kolb KE (1972) Differential scanning calorimetry of single acid triglycerides: effect of chain length and unsaturation. J Am Oil Chem Soc 49:118–123CrossRefGoogle Scholar
  48. 48.
    Hagemann JW, Tallent WH, Barve JA, Ismail IA, Gunstone GD (1975) Polymorphism in single-acid triglycerides of positional and geometric isomers of octadecenoic acid. J Am Oil Chem Soc 52:204–207CrossRefGoogle Scholar

Copyright information

© AOCS 2009

Authors and Affiliations

  1. 1.US Department of Agriculture, Agricultural Research ServiceNational Center for Agricultural Utilization ResearchPeoriaUSA

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