Grasas y Aceites (Mar 2015)

Thumba (Citrullus colocynthis L.) seed oil: a potential bio-lubricant base-stock

  • K. Kamalakar,
  • G. N.V.T. Sai Manoj,
  • R. B.N. Prasad,
  • M. S.L. Karuna

DOI
https://doi.org/10.3989/gya.0576141
Journal volume & issue
Vol. 66, no. 1
pp. e055 – e055

Abstract

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Thumba seed oil, a minor, renewable tree borne oil, was exploited for the preparation of biolubricant base-stocks. The different base-stocks prepared were epoxy thumba oil (ETO), branched, 2-ethylhexyl ester (T2-EtHE), and polyol esters, namely, neopentyl glycol (TNPGE), trimethylolpropane (TTMPE) and pentaerythritol (TPEE) esters of thumba fatty acids. All the base-stocks were thoroughly characterized using spectral techniques. When evaluated for lubricant properties, ETO showed much higher viscosity (216.9 cSt), good oxidative stability (RBOT Method, ASTM D 2272) (20 min) and weld load (ASTM IP 239) (180 kg) behavior when compared to the branched and polyol esters. Polyol esters, T2-EtHE, TNPGE and TTMPE (−9 to −18 °C) showed low pour points compared to ETO and TPEE. The thermal stabilities (Thermo gravimetric analysis, TGA) of ETO and TPEE (425 °C) were higher compared to other base-stocks. The lubricant properties of ETO matched well with ISO VG 220 and Aviation Grade 100 lubricant specifications, while polyol esters can be well exploited for hydraulic and metal working fluid applications.

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