Comparative Study between ISO VG-46 and Biolubricants Synthesized from Neem (<i>Azadirachta indica)</i> and Calabash (<i>Lagenaria siceraria) </i>Seed Oils Using Calcium Oxide (CaO) Catalyst Obtained from Eggshells for Application as Hydraulic Fluids

Abstract

The research focused on the extraction of oil from Neem (Azadirachta indica) and Calabash (Lagenaria siceraria) seeds. The extracted oils were characterized to determine their physicochemical properties, which were assessed according to AOAC and ASTM methods. The percentage yields of Neem oil and Calabash oil were 34.50±0.25% and 31.00±0.20 %, respectively. The acid value of Neem and Calabash oils was 8.91±0.10 mg KOH/g and 3.23±0.15 mg KOH/g, respectively. Regarding percentage Free Fatty Acids (% FFA), Neem oil was determined to be 4.87±0.20 while Calabash oil had a value of 1.73±0.10. As for the saponification value, Neem oil had a value of 137.55±0.25 mg KOH/g, while calabash oil had a value of 238.84±0.30 mg KOH/g. The iodine values of neem and calabash oil were 68.00±0.20 and 66.20±0.15 g/100g, respectively. Also, the density for neem oil was determined to be 0.85±0.10 g/mL, while that of calabash oil was 0.90±0.10 g/mL. Furthermore, the extracted Neem and Calabash oils were used to synthesize biolubricants via esterification and transesterification processes using pentaerythritol and Calcium Oxide (CaO) obtained from eggshells, with yields of 60.80±0.15 % for the Neem biolubricant and 53.00±0.20 % for the Calabash biolubricant. The properties of the synthesized biolubricants were determined and compared with those of a mineral lubricant (ISO VG 46). Additionally, tribology studies showed that the COF for Neem and Calabash biolubricants is 0.041 and 0.054, respectively, at a 10N load. Compared with the COF of 0.086 for ISO VG 46 at 10N load, these biolubricants could provide better friction reduction than ISO VG 46; hence, they are suitable for possible application as hydraulic oil.