title: Synthesis, characterization, and evaluation of 10-undecenoic acid-based epithio derivatives as multifunctional additives.
abstract: Novel epithio compounds from alkyl epoxy undecanoates (n-alkyl, C1, C4, and C6; isoalkyl, C3, C4, and C8) were synthesized using an ammonium thiocyanate in ionic liquid 1-methylimidazolium tetrafluoroborate/H2O (2:1) solvent system in 85-90% yields by gas chromatographic (GC) analysis. The synthesized products were characterized by (1)H and (13)C nuclear magnetic resonance spectroscopy, Fourier transform infrared spectroscopy (FTIR), gas chromatography, and GC mass spectral (GC-MS) analyses and evaluated for their antioxidant, extreme pressure (EP), and antiwear (AW) properties in three different base oils, namely, epoxy jatropha fatty acid n-butyl esters (EJB), di-2-ethylhexyl sebacate (DOS), and mineral oil (S-105). Among the synthesized products, n-butyl epithio undecanoate exhibited superior antioxidant property (229.2 °C) compared to butylated hydroxytoluene (BHT, 193.8 °C) in base oil DOS and comparable performance in EJB and S-105 base oils. All of the epithio derivatives exhibited significantly enhanced weld point for the base oils EJB and DOS at 2 wt % level and displayed moderate enhancement in S-105 base oil. Methyl epithio undecanoate at 0.6% concentration exhibited considerable improvement in the wear scar of DOS base oil. The synthesized epithio derivatives have potential as multifunctional additives in lubricant formulations.
authors.affiliation: Centre for Lipid Research, CSIR-Indian Institute of Chemical Technology , Hyderabad 500 007, Andhra Pradesh, India.
authors.forename: Gorla
authors.initials: G
authors.lastname: Geethanjali
authors.forename: Korlipara V
authors.initials: KV
authors.lastname: Padmaja
authors.forename: Arukali
authors.initials: A
authors.lastname: Sammaiah
authors.forename: Rachapudi B N
authors.initials: RB
authors.lastname: Prasad
mesh_terms: D000975:Antioxidants / Q000737:chemistry; D002084:Butylated Hydroxytoluene / Q000737:chemistry; D003652:Decanoic Acids / Q000737:chemistry; D005227:Fatty Acids / Q000737:chemistry; D008401:Gas Chromatography-Mass Spectrometry; D031286:Jatropha / Q000737:chemistry; D009682:Magnetic Resonance Spectroscopy; D010938:Plant Oils / Q000737:chemistry; D017550:Spectroscopy, Fourier Transform Infrared; D014476:Undecylenic Acids / Q000138:chemical synthesis*
chemical_list: D000975:Antioxidants; D003652:Decanoic Acids; D005227:Fatty Acids; D010938:Plant Oils; D014476:Undecylenic Acids; D002084:Butylated Hydroxytoluene; C538763:undecylenic acid; C037634:di-2-ethylhexyl sebacate
keywords: 10-undecenoic acid; antioxidant; antiwear; biolubricant; epithio derivatives; extreme pressure additive; ionic liquid; mineral oil; synthetic ester