Korlipara V. Padmaja

Synthesis and evaluation of novel acyl derivatives from jatropha oil as potential lubricant basestocks.

A novel class of jatropha oil-based acylated derivatives from hydroxy alkyl esters of jatropha fatty acids (C1, C3, C4, and C8) and various anhydrides (C2, C3, C4, and C6) were synthesized and their physicochemical and lubricant properties reported. Jatropha fatty acid alkyl esters were dihydroxylated using the in situ performic acid method and further acylated with different anhydrides to produce acylated derivatives. Acylated derivatives of dihydroxy jatropha fatty acid alkyl esters were charaterized by NMR, FTIR, GC, and GC-MS analysis and were evaluated for their viscosity, viscosity index, pour and flash points, and oxidation stability. Most of the derivatives are either in ISO VG 22 or 32 viscosity grade with good viscosity index. It was observed that increase in acyl chain length and branching in the end-chain ester improved the pour point of the diacyl derivatives. All of the hexanoylated esters exhibited better oxidation stability compared to other acylated products, and their pour points are comparable to those of synthetic esters such as TMP trioleates. In general, isoalcohol esters with longer acyl chains showed promise as potential candidates for hydraulic fluids and metal-working fluids in ISO VG 22 and 32 viscosity range.

Multifunctional lubricant additives derived from natural amino acids and methyl oleate

Novel multifunctional additives were synthesized from methyl oleate via thioglycolic acid addition followed by condensation with different amino acid methyl esters. Seven additives were synthesized and the structures of all the additives were fully characterized by mass, IR and NMR spectral studies. The tribological properties were evaluated using laboratory tribotests in biolubricant base oil, which suggest that all the prepared compounds act as antiwear and extreme pressure additives. Among the synthesized additives, heterocyclic containing compounds exhibited superior performance compared to others. Antioxidant properties evaluated using differential scanning calorimetry reveal that all the additives improved the oxidation stability of base oil with heterocyclic based additives exhibiting better performance compared to commercial antioxidant BHT. The synthesized amino acid-based derivatives have potential as biodegradable multifunctional additives in biolubricant formulations.

Synthesis, Characterization, and Evaluation of 10-Undecenoic Acid-Based Epithio Derivatives as Multifunctional Additives

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.

Tribological studies of α-lipoic acid esters as effective environmentally friendly multifunctional lubricant additives

ABSTRACT Enzymatic synthesis of six esters of α-lipoic acid with different fatty alcohols and diols was carried out to produce novel compounds with lubricant additive properties. The synthetic route was mild and efficient with good yields. The synthesized compounds were characterized by IR, NMR, and mass spectral studies and screened for their thermal stability, antiwear (AW), extreme pressure (EP), and antioxidant (AO) properties. The tribo tests in a synthetic base fluid indicated that all the synthesized compounds act as antiwear and extreme pressure additives. All the prepared esters exhibited very good thermal stability and excellent antioxidant properties with better performance compared to commercial antioxidant BHT as determined by differential scanning calorimetry.

Catalytic Cracking of Pinus roxburghii Resin for Liquid Fuels

The development of alternative sources for energy and chemicals, particularly the use of plant biomass as a renewable resource for fuel or chemical feed stocks, has received much recent attention. The resin (biocrude) obtained from Pinus roxburghii, a resinous tree, was investigated as a potential source for liquid fuels in a fluidized bed reactor. The feed was studied for yield conversion data under different catalysts to feed ratio at different temperatures. High conversions of biocrude to liquid fuels were observed with maximum middle distillates selectivity at a catalyst/oil ratio of 1.8 and reaction temperature of 460°C. Gas chromatography analysis results indicated that the middle distillates obtained by catalytic cracking of P. roxburghii biocrude has a normal distribution of carbon number with high values from C10–C18 carbon atoms.

Resinous Species as Source of Biofuels

Biofuels are non-polluting, locally available, and reliable fuels obtained from renewable sources. The rising cost of petroleum-based liquid fuels, due to the depletion of oil sources, has brought biofuels back into focus. Laticiferous and resinous plants can be used for the production of biofuels by catalytic cracking of their non-polar extracts (biocrude). In the present work six resinous species belonging to the families Rubiaceae, Simaroubaceae, Leguminoseae, Dipterocarpaceae, Pinaceae, and Compositae were selected and studied for their potential to yield biocrude, which can be processed into biofuels. Results of studies carried out on upgrading the biocrudes by catalytic cracking using a commercial catalyst are presented.

Catalytic Cracking of Euphorbia Species: Analysis of the Naphtha Fractions

The development of alternate sources of energy, particularly the use of plants as renewable sources for fuel, has received much attention recently. The potential of two indigenous arid land petrocrops, E. royleana and E. neriifolia, as a source of hydrocarbon fuels was explored. Biocrudes extracted from these plant species were catalytically upgraded to liquid fuels using fluidized catalytic cracking. Naphtha fractions obtained by cracking of biocrudes were analyzed to give the detailed and group-wise distribution of paraffinic, isoparaffinic, oleofinic, naphthenic, and aromatic components. These naphtha fractions are similar in composition to the naphtha obtained from petroleum crudes.