Experimental analysis of tribological performance of base ficus carica vegetable oil with different polymers as additives using four ball tribometer

Abstract

The need to use vegetable lubricants has been driven by the widespread concern for environmental issues, especially in industries that overuse petroleum lubricants. This research examined the tribological characteristics of vegetable-based lubricants by adding additives such as ethylene–vinyl acetate (EVA) and Eichhornia crassipes carboxymethyl cellulose (EC-CMC) polymers to study the viscometric response of the lubricants. The test was conducted using four ball-tester, and analyzed in terms of coefficient of friction (COF), wear scar diameter (WSD), and wear scar rate, respectively. The results showed that with the addition of each additive enhanced the tribological properties significantly but yielded poor results with 0.5% additives for both samples. The characterization investigation showed that ficus carica (Fig) oil responded effectively to the addition of various additives when conducted thermogravimetric analysis (TGA) and Fourier transform infrared (FT-IR) spectroscopy. Under 100 kg load and speed of 1200 rpm, base Fig lubricant yielded a higher COF of 0.193, while blended EVA and EC-CMC gave lower COF of 0.161 and 0.171, while the lowest wear scar diameter was with 1.5 wt% EVA (0.39 mm) and 1 wt% EVA (0.41 mm), respectively. Comparing all the lubricants under 1500 rpm, the base Fig lubricant yielded 0.317, while 1.5 wt% EVA, 1.5 wt% EC-CMC, SEA 5W 30 gives COF of 0.287, 0.263, and 0.239, respectively. The study revealed that the reduction in the COF and wear scar diameter was due to the formation of the film by the included additive.