Comparative assessment of chemically modified Terminalia catappa L. kernel oil samples – A promising ecofriendly transformer fluid

•Esterification-transesterification (MTCKOt) and epoxidation-esterification (MTCKOe) methods were used to modify Terminalia catappa kernel oil (TCKO).•Sample obtained by MTCKOe method gave better transformer oil properties than MTCKOt.•Physicochemical properties like dielectric strength and pour point of MTCKOt and MTCKOe, were (48.55 KV and ̶ 5) and (50.05 KV and ̶ 8), respectively.•There was improvement in the percentage saturated fatty acid composition of TCKO after the modification. This work is centered on the chemical modification and characterization of Terminalia catappa kernel oil (TCKO) for possible use as replacement for mineral transformer fluid. Solvent extraction method was used for the extraction of TCKO. Transesterification and epoxidation-esterification methods were used for the modification of the TCKO. The physicochemical characteristics of the TCKO and Modified Terminalia catappa kernel oil (MTCKO) were determined using standard methods. Fourier Transform Infrared (FTIR) spectrometry, Scanning Electron Microscope (SEM) and Differential Scanning Calorimetric (DSC), were respectively, used to determine the functional groups, surface morphology and oxidative stability of TCKO and MTCKO samples. At 55 °C, 150 min and 0.5 mm particle size, kernel oil yield was 60.45% (by weight). The dielectric strength of MTCKO obtained by transesterification and epoxidation-esterification methods were 48.55 KV and 50.05 KV, respectively. The ANOVA and the Tukey’s post hoc analyses indicated that time, mole ratio and temperature effects were significant for the transesterification process; while time, molar ratio of H2O2 and temperature effects were significant for the epoxidation process. Physicochemical properties of TCKO and MTCKO samples indicated their potential for use as transformer fluid.