Synthesis and Frictional Characteristics of Bio-Based Lubricants Obtained from Fatty Acids of Castor Oil

• Published in: Lubricants 2023-01, Vol.11 (2), p.57
• Main Authors: Campos Flexa Ribeiro Filho, Paulo Roberto, Rocha do Nascimento, Matheus, Otaviano da Silva, Silvia Shelly, Tavares de Luna, Francisco Murilo, Rodríguez-Castellon, Enrique, Loureiro Cavalcante, Celio
• Format: Article
• Language: English
• Subjects: Biological products; biolubricant; Biomedical materials; Castor oil; Chemical properties; Coefficient of friction; Depletion; Environmental impact; Epoxidation; Esterification; Ethylene oxide; Fatty acids; Four ball testers; Friction; Hydrogenation; Lubricants; Lubricants & lubrication; Lubrication and lubricants; Mechanical properties; Mineral oils; NMR; Nuclear magnetic resonance; oxirane ring opening; Potassium; Production processes; Ring opening; Sodium; Spectrum analysis; Synthesis; Testing; Tribology; Vegetable oils; Viscosity; Wear rate
• ISSN: 2075-4442; 2075-4442
• DOI: 10.3390/lubricants11020057

The depletion of oil reserves and concerns about the environmental impact of the use and incorrect disposal of mineral lubricants have been promoting the development of bio-based lubricants. In this study, biolubricants obtained from fatty acids of castor oil were synthesized by esterification (>wt.%93), epoxidation (>wt.%92), and oxirane ring opening reactions using water (>wt.%92) or 2-ethylhexanol (>wt.%94) as nucleophilic agents. The frictional characteristics of the synthesized samples were obtained through tribological tests performed in a four-ball tester and compared with a commercial mineral oil. The sample obtained through oxirane ring opening with water showed the best frictional performance (FC = 0.0699 ± 0.0007) among the prepared samples, with equivalent wear rate (WSD = 281.2 ± 5.54 μm) and ca. 20% lower friction coefficient when compared to the commercial mineral oil, indicating its great potential for replacing mineral fossil oils.