The purpose of this paper is to investigate some cheap and highly stable additives to improve the quality of lubricating oil.
The study was performed using phenol, p‐cresol and pyrogallol as antioxidants. The concentration of each antioxidant was varied between 0 and 1 per cent. Sample (50 ml) blended with the antioxidant was taken in the same trap. The trap was placed on water both maintained at a temperature of 50°C. Air was bubbled for the time duration of 6 h. After 6 h, the contents of the trap were carefully collected and characterized. The oxidation was performed in a specially designed glass made U‐shaped trap in the absence and presence of antioxidants. The trap containing sample was tied with an iron stand. Air was bubbled through the sample. The bubbling was assisted by the suction pump at room temperate (24°C). The sample was aerated for time duration of 6 h. After 6 h, the contents of the trap were carefully collected in a dried bottle for physicochemical tests.
The results indicate that phenol is the best antioxidant in concentration of 0.5 per cent amongst the three antioxidants used at room temperature as well as at 50°C. Amongst the antioxidants used, the order of suitability is phenol > pyrogallol > p‐creosol.
The antioxidants studied will help increase the service time of the lubricant to save money and to avoid environmental problems arising from careless disposal of used lubricating oils.
