No abstract

No abstract

No abstract

Vegetable oils are regarded as renewable energy for future generations due to its biodegradability, high thermal properties, and good lubricity. Some of the disadvantages of vegetable oil are high pour point, low oxidative stability, and limited viscosity range. In this paper, we evaluate and compare the rheological properties of rice bran oil (RBO) with various proportions of low-density polyethylene (LDPE) and ethyl vinyl acetate (EVA) separately. The thermal stability also has been tested in this paper. Both the polymers have different mode of improving the viscosity and LDPE is found to be a viscosity index booster. The percentage improvement in viscosity for various proportions of polymers has been evaluated at various temperatures. It is seen that LDPE is more suited for engine oil applications since the high temperature rheology is more important in the selection of these lubricants. The viscosity variation of biolubricant formulations with temperature were validated with Walther equation. The biodegradability of both the polymers was estimated and compared with a commercially available mineral oil. The addition of EVA and LDPE in RBO reduces the biodegradability to a smaller extent but it is better than commercially available mineral oil SAE20W40.

Mineral oils, which are mainly used as lubricant base oils in industries and automobiles, are non-bio degradable, toxic and cause harm to our environment. A large quantity of the lubricants, approximately 150 million barrels are used per year. In order to tackle the adverse effects of mineral oils on the environment, an idea emerged to replace mineral oils with an environmentally friendly bio lubricant. Vegetable oils having good lubricating properties, biodegradability and non-toxicity became the forerunners in these new bio lubricant formulation methods. In this paper, physical, chemical, tribological properties and oxidative stability of rice bran oil with two non-toxic additives, namely turmeric oil and halloysite nano clay, were evaluated. The gas chromatography method was used for structure elucidation. The tribological properties were evaluated by a four-ball apparatus as per ASTM D4172-94. Rice bran oil with 0.1% halloysite nano clay and 1.5% turmeric oil has shown 16.1% and 13.4% reduction in coefficient of friction and wear scar diameter, respectively, whereas the acid and peroxide value has reduced to 49% and 52%, respectively, when compared with the pure rice bran oil. The effect of turmeric oil in rice bran oil was evaluated using DFT-based quantum chemical studies using Gaussian 09, and it was found that the curcumin, which is the major component of turmeric oil, has shown good anti-oxidant behaviour. The properties of rice bran oil were observed to increase at a synergic combination of turmeric oil and halloysite nano clay.