Physicochemical properties of Citrullus lanatus (Melon Seed) and Cocos nucifera (Coconut) Oil Blends and applications as cutting fluid

Abstract

This research focused on the physicochemical properties of blended vegetable oils using Citrullus lanatus oil (melon seed oil-MSO) and Cocos nucifera oil (coconut oil-CNO) as the case study for use as cutting fluid in machining operations. In the investigation carried out on the oils, physical properties such as viscosity, flashpoint, specific gravity, density, pour point, cloud point and thermal stability were determined through a conducted laboratory experiment. The study also involved the determination of chemical properties like iodine value, acidic value, saponification value, hydrogen peroxide value and free fatty acid value according to each testing standards. The oils were blended at ratios 20:80, 40:60, 60:40 and 80:20 to obtain suitable blending ratios. Based on the analysis, the physicochemical properties of oil blend at 60%:40% provides a suitable results for use as a cutting fluid in machining operations with the following properties: acidic value (1.683mgNaOH/g), free acid value (0.842mgNaOH/g), specific gravity (41.467g), density (1.658g/mL), viscosity at 40 0C (22.50pa.s), viscosity at 120 0C (4.00pa.s), iodine value (139 mgKOH/g), pour point (–10), flash point (284 0C), saponification value (121 mgKOH/g), Hydrogen peroxide value (4.91 mgKOH/g) and cloud point (10 0C). The thermal stability of this ratio is also appreciable for cutting fluid. Based on the above results, the research shows that blended vegetable oils can be adapted as a suitable substitute for mineral oil in machining operations due to their improved qualities and functionalities.