Development of Fully Bio‐Based Lubricants from Agro‐Industrial Residues under Environmentally Friendly Processes

Abstract

Biolubricants are becoming interesting alternatives to mineral lubricants. Despite their advantages, development of lubricants from vegetable oils may compete with food production, turning their use impractical due to socio-economic aspects. Here, cardanol is used as raw material in the synthesis of novel biolubricants under environmentally friendly conditions. These compounds are characterized by NMR and Fourier transform infrared spectroscopy. Thermal-oxidative studies show the elevated stability and higher onset oxidative temperatures. Tribological analyses performed under high-frequency linear-oscillation motion indicate lower coefficients of friction and wear rates compared to a synthetic oil. Therefore, cardanol, under simple, fast, and sustainable processes can be transformed into valuable alternatives for petroleum-based lubricants. Practical Applications: The novel cardanol-based biolubricants presented in this work show interesting chemical and lubricity properties superior to standard synthetic oils, which make them potential substitutes for the current oil-based products used as lubricants. Additionally, the ecofriendly methodologies employed reduce significantly the reaction time as well as eliminating the need for catalysts or solvents, making these processes viable alternatives for the traditional methods reported in literature for the synthesis of this class of compounds.

Synthesis of Emulsion by Using Vegetable Oil Modified by Titanium Dioxide (TiO2) Nanoparticles: A Peculiar Source for Synthesis of Bio‐Based Lubricant and Novel Approach to Enhance the Efficiency of Emulsion

“…On the bases of previously reported preparative approaches of emulsions, [1][2][3]13,15] the present study emphasizes that the TiO 2 NPs enhanced the inhibition efficiency of emulsion and sustained the characteristic properties of VONE. The characteristic results infer that the Tergitol Np-7 was recommended as a fine surfactant that best matched with base oil for the synthesis of vegetable O/W nanoemulsions and synthesized emulsion characterized by different techniques like DLS, zeta potential, oil concentration, ESI, conductivity, pH, KV, and results compared with reference emulsion.…”

“…The cold rolling process is an important industrial process of cold rolling industries, during this process thickness of metal sheet reduces by applying a huge force through work rolls and chances of friction and heat losses are possible. So in the cold rolling process, it is a challenge to overcome frictional parameters [1,2] between work roll and strip for a better surface quality of the strips and heat losses by the usage of the emulsion as an interface between the metal sheet and work roll. The adequate formation of the emulsion with advanced efficiency is very essential to run an industrial process smoothly because the imbalance formation of emulsion affects the cooling capabilities and low oil contents or the percentage of oil in emulsion will reduce the lubricant film at the interface as well as a rise in the temperature.…”

Synthesis and Physicochemical Properties of Low Viscosity 2‐Ethylhexyl Alkyl Ethers Made from Palm‐Based Esters as Potential Biolubricant

“…[31] A higher OOT indicates higher oxidation stability of the material. [24,30] Referring to OOT values in Table 1, the EHAE (1-3) with saturated alkyl chain exhibited high OOT in the range of 181-184 °C with negligible effect from the increment of alkyl chain length from C12:0 to C18:0. On the other hand, EHO ether (4) with an alkene moiety is more susceptible toward oxidation and thus showed lower OOT (165 °C) than saturated EHAE (1-3).…”

“…Thermal stability was determined by the onset temperature (T onset ) which is the starting or initial temperature of the weight loss of the sample. [24] Thus, a higher T onset implies higher thermal stability of a material. [25] For EHAE with saturated alkyl chain, a trend of higher T onset ranging from 200 to 249 °C was observed with the increment of alkyl chain length from C12:0 to C18:0 (1-3) (Figure 5b and Table 1), attributable to the lower volatility of EHAE with increasing molecular weight.…”

“…Evaluation of the oxidative stability of lubricant was conducted using PDSC through measuring the OOT of a sample, which is commonly used in the lubricant industry. [4,24,30] The OOT is the temperature at which a rapid increase in the rate of oxidation is observed. It is determined by extrapolating a tangent drawn on the steepest slope of exotherm to the baseline.…”