Synthesis and characterisation of palm oil-based biolubricant for application as cutting fluid

Growing environmental concerns over the use of mineral-based lubricants have accelerated research into eco-friendly alternatives such as biolubricants. This study aims to synthesise and characterise biolubricants formulated from palm oil methyl ester (POME) and Aloe vera (AVE). Several formulations with different POME:AVE volume ratios (100:0, 80:20, 70:30 and 60:40) were evaluated for their viscosity (ASTM D445), density (pycnometer), pour point (ASTM D97), flash point (ASTM D92), thermal stability (15 minutes examinations while sample is heated) and cooling efficiency during CNC lathe machining. The results show that the 60:40 POME:AVE ratio demonstrated the best overall performance, with the highest viscosity, lowest pour point and notable thermal stability. These improved properties are believed to result from the presence of bioactive compounds in Aloe vera, particularly acemannan, polysaccharides and natural antioxidants, which enhance molecular cohesion, thermal resistance and oxidative stability. Additionally, cooling tests showed that the 60:40 biolubricant formulation significantly reduced cutting temperatures compared to commercial and dry machining conditions. These findings suggest that biolubricants formulated from POME and AVE have strong potential as sustainable and high-performance alternatives in metalworking applications.