Sains Malaysiana 44(3)(2015): 405–412

Lubricity and Tribological Properties of Dicarboxylic Acid and Oleyl Alcohol Based Esters

(Sifat Pelinciran dan Tribologi Ester Berasaskan Asid Dikarboksilik dan Alkohol Oleil)

JUMAT SALIMON*, WALED ABDO AHMED, NADIA SALIH, MOHD AMBAR YARMO

& DARFIZZI DERAWI

School of Chemical Sciences and Food Technology, Faculty of Science and Technology

Universiti Kebangsaan Malaysia, 43600 Bangi, Selangor Darul Ehsan, Malaysia

Received: 23 April 2014/Accepted: 26 September 2014

ABSTRACT

Synthesis of new lubricants nowadays is increasing to improve the lubricity properties and the quality of lubricant. In the current study, eight diesters with different chemical structures were tested in terms of their suitability as lubricants. The esterification reaction was carried out using Dean-Stark distillation method with some modification. Fourier transformation infra-red (FTIR), proton and carbon nuclear magnetic resonance (1H-NMR and 13C-NMR), were used to verify the chemical structure of the diesters. The results showed that the dioleyl pimelate (DOlP), dioleyl adipate (DOlA), dioleyl glutarate (DOlG), and dioleyl succinate (DOlSuc) showed good low temperature properties with pour point values at -10, -12, -16 and -20°C, respectively. The dioleyl dodecanedioate (DOlD) indicated remarkable flash point value at 305°C and had slightly high oxidative stability temperature (OT) at 183°C. The flash point increased with the number of carbons for dicarboxylic acid used, while oxidative stability was affected by the unsaturated of oleyl alcohol. Tribological study showed that the diesters were non-Newtonian except DOlD, which was Newtonian fluid. All the diesters were found to be boundary lubricants with low coefficients of friction (COF). Overall, the results indicated that all the diesters studied can be used as lubricating base oils.

Keywords: Coefficients of friction; flash point; oxidative stability; pour point; tribological properties

ABSTRAK

Sintesis pelincir pada masa ini telah meningkat untuk menambahbaik sifat pelinciran dan kualiti sesuatu minyak pelincir. Dalam kajian ini, lapan jenis ester berlainan struktur kimia telah diuji kesetabilannya untuk kegunaan pelincir. Tindak balas pengesteran telah dilakukkan dengan menggunakan penyulingan Dean-Stark dengan sedikit pengubahsuian. Struktur kimia diester terhasil dibuktikan dengan menggunakan transformasi Fourier inframerah (FTIR), nuklear magnetik resonan proton dan karbon (1H-NMR dan 13C-NMR). Hasil kajian menunjukkan dioleil pimelat (DOlP), dioleil adipat (DOlA), dioleil glutarat (DOlG) dan dioleil suksinat (DOlSuc) mempunyai sifat suhu rendah yang baik dengan nilai takat tuang masing-masing pada -10, -12, -16 dan -20°C. Dioleil dodekanedioat (DOlD) pula menunjukkan nilai takat kilat yang tinggi pada 305°C dan mempunyai kestabilan oksidatif (OT) yang agak tinggi pada 183°C. Takat kilat ester meningkat dengan peningkatan bilangan karbon asid dikarboksilik yang digunakan, sementara kestabilan oksidatif dipengaruhi oleh ketaktepuan alkohol oleil. Kajian tribologi menunjukkan diester yang terhasil bersifat bukan-Newtonian kecuali DOlD, yang bersifat bendalir Newtonian. Kesemua diester menunjukkan sifat pelincir sempadan dengan pekali geseran (COF) yang rendah. Secara keseluruhannya, hasil kajian menunjukkan kesemua diester kajian boleh digunakan sebagai minyak asas pelincir.

Kata kunci: Kestabilan oksidatif; pekali geseran; sifat tribologi; takat kilat; takat tuang

REFERENCES

Adhvaryu, A., Erhan, S.Z., Liu, Z.S. & Perez, J.M. 2000. Oxidation kinetics studies of unmodified and genetically modified vegetable oils using pressurised differential scanning calorimetry and nuclear magnetic resonance spectroscopy. Thermochimica Acta 364(1): 87-97.

Aigbodion, A.I. & Bakare, I.O. 2005. Rubber seed oil quality assessment and authentication. Journal of American Oil Chemical Society 82: 465-469.

ASTM 2011. Standard Test Method for Wear Preventive Characteristics of Lubricating Fluid (Four-ball Method). West Conshohocken, PA (USA): ASTM.

Bair, S. 2000. Pressure-viscosity behavior of lubricants to 1.4GPa and its relation to EHD traction. Tribology Transaction 43(1): 91-99.

Batchelor, G. 2000. An Introduction to Fluid Mechanics. Cambridge: Cambridge University Press.

Bhushan, B. 2013. Boundary Lubrication and Lubricants. In Principles and Applications of Tribology. New York: John Wiley & Sons, Ltd.

Bloch, H.P. 2009. Practical Lubrication for Industrial Facilities. Georgia: The Fairmont Press Inc.

Boyde, S. 2005. Hydrolytic stability of synthetic ester lubricants. Lubrication Sciences 16(4): 297-312.

Buenemann, T.F., Boyde, S., Randles, S. & Thompson, I. 2003. Synthetic lubricants non aqueous. Fuels and Lubricants Handbook: Technology, Properties, Performance, and Testing., West Conshohocken, PA: ASTM International. Chapter 10, pp. 249-266.

Bushan, B. 2002. Introduction to Tribology. New York: John Wiley & Sons Inc. p 533.

Coussot, P., Tocquer, L., Lanos, C. & Ovarlez, G. 2009. Macroscopic vs local rheology of yield stress fluids. Journal of Non-Newtonian Fluid Mechanics 158: 85-90.

Durak, E., Çetinkaya, M., Yeinigün, B. & Karaosmanoǧlu, F. 2004. Effects of sunflower oil added to base oil on the friction coefficient of statically loaded journal bearings. Journal of Synthetic Lubrication 21(3): 207-222.

El-Magly, L.A., Nasr, E.S. & El-Samonoudy, M.S. 1990. Optimal preparation conditions for some diester-based synthetic lubricants. Journal of Synthetic Lubrication 7(2): 89-103.

Fatemi, S.H. & Hammond, E.G. 1980. Analysis of oleate, linoleate and linoleate hydroperoxides in oxidised ester mixtures. Lipids 15: 379-385.

Kalin, M., Velkavrh, I. & Vizintin, J. 2009. The Stribeck curve and lubrication design for non-fully wetted surfaces. Wear 267: 1232-1240.

Kubouchi, H., Kai, H., Miyashita, K. & Matsuda, K. 2002. Effects of emulsifiers on the oxidative stability of soybean oil TAG in emulsions. Journal of American Oil Chemical Society 79: 567-570.

Lawate, S.S. & Lal, K. 1998. High oleic polyol esters, compositions and lubricants, functional fluids and greases containing the same. U.S. Patent 5773391.

Lee, P.J., Robert, L. & Prasad, S.V. 2003. Novel microemulsion enhancer formulation for simultaneous transdermal delivery of hydrophilic and hydrophobic drugs. Pharmaceutical Research 20(2): 264-269.

Moser, B.R. 2009. Comparative oxidative stability of fatty acid alkyl esters by accelerated methods. Journal of the American Oil Chemists' Society 86: 699-706.

Murrenhoff, H.R.A. 2003. Environmentally friendly oils. Fuels and Lubricants Handbook: Technology, Properties, Performance, and Testing, edited by Totten, G.E., West Conshohocken, PA: ASTM International. Chapter 11. pp. 267-295.

Pavia, D.L., Lampman, G.M., Kriz, G.S. & Vyvyan, J.R. 2008. Introduction to Spectroscopy 4th ed. Belmont: Brooks/Cole, Cengage Learning.

Romero, M.D., Gomez, J.M. & Diaz-suelto, B.G. 2011. A study of the influence of alcohols in the synthesis of short chain esters. Chemical Engineering Transactions 24: 37-42.

Rudnick, L.R. 2006. Synthetics, Mineral Oils, and Bio-based Lubricants: Chemistry and Technology. New York: CRC/ Taylor & Francis Group. Chapter 21. pp. 22-31.

Salimon, J., Salih, N. & Yousif, E. 2012. Triester derivatives of oleic acid: The effect of chemical structure on low temperature, thermo-oxidation and tribological properties. Industrial Crops and Products 38: 107-114.

Salimon, J., Salih, N. & Yousif, E. 2011. Synthetic biolubricant basestocks from epoxidised ricinoleic acid: Improved low temperature properties. Chemistry in Industry 60(3): 127-134.

Salimon, J., Salih, N. & Yousif, E. 2010. Chemically modified biolubricant basestocks from epoxidised oleic acid: Improved low temperature properties and oxidative stability. Journal of Saudi Chemical Society 15: 195-201.

Sudimack, J.J., Wenjin, G., Werner, T. & Robert, J.L. 2002. A novel pH-sensitive liposome formulation containing oleyl alcohol. Biochimica et Biophysica Acta (BBA)-Biomembranes 1564(1): 31-37.

*Corresponding author; email: jumat@ukm.edu.my