Thermal Behavior and Fluidity of Biolubricant Synthesized from Mango (Mangifera indica L.) Kernel Oil Blended With Cold Flow Property Improvers

Abstract

Fossil fuel and conventional lubricant are not environmentally friendly, non-biodegradable, toxic, and non-renewable. Therefore, the objective of this paper is to evaluate the thermal and fluidity of the biolubricant synthesized from Mango (Mangifera indica L.) kernel oil (MKO) blended with cold flow property improvers using standard techniques. A twostep process of esterification and transesterification was employed to produce fatty acid methyl ester (FAME) from MKO mentioned as Mango kernel methyl ester (MKME). Double transesterification of the MKME with trimethylolpropane (TMP) in the presence of sodium methoxide yielded 95 % Mango oil based trimethylolpropane ester (MOTE). Anotherof the MKME was used to synthesize biolubricant using the conventional epoxidation which yielded 70 % Mango oil based epoxidised biolubricant (MEB-L). A simultaneous SDT 2960 TG/DTA from TA instrument analysis reveals MOTE to present higher thermal stability (302 °C) with 5 % weight loss compared to MEB-L (250.5 °C) with similar 5 % weight loss. Degradation was endothermic for both MOTE and MEB-L and predominantly followed a single step of weight lost. Degradation becomes rapid at temperature above 300 °C for MOTE while for MEB-L degradation started at temperature above 250 °C. At about the temperature range of 850 - 900 °C, 95 % of MEB-L and 77 % of MOTE were lost respectively. The relative thermal stability of MOTE would be attributed to the alcohol substitution of the branch chain Trimethylolpropane (TMP) resulting into a more thermally stable Triester (MOTE). The results of the analysis of the cold flow properties reveal that various blend of MEB-L with n-BE portrays better pour and cloud point as they are lower than their counterpart (blends of MOTE with n-BE) and (blends of even MOTE & MEB-L with EAA for both cloud/pour points).