3.3.2. Viscosities of the synthesized PKO biolubricants samples at 40 °C and at 100 °C
The viscosities of PKO biolubricants synthesized by transesterification with TMP PKBLT were 42.53 cSt at 40 °C and 10.65 cSt at 100 °C, respectively. Similarly, the viscosities of PKO biolubricants synthesized by epoxidation-esterification PKBLE were 44.69 cSt at 40 °C and 11.42 cSt at 100 °C, respectively. From the values in Table 1, it could be seen that viscosities values of the PKBLE sample were comparatively higher than those of the PKBLT sample. For the PKO sample, its viscosity was lower than the values reported for PKO and palm oil, by Alang et al. [1] and Reddy et al. [43], respectively. However, the PKO sample viscosity was lower than the value reported for Jatropha oil by Menkiti et al. [4]. These values for PKO biolubricant samples were less than those of biolubricant from PKO reported as 480.63 cSt at 40 °C and 20.54 cSt at 100 °C, by Alang et al. [1]. Also, the values of the viscosities of PKO biolubricants in this work were lower, when compared to Jatropha bio-lubricants with values of 55.17 cSt at 40 °C and 10.96 cSt at 100 °C, as reported by Bilal et al. [44]. The values for PKO biolubricant are comparable with those of petroleum lubricants which were evaluated to be 46.476 cSt and 6.940 cSt, at 40 °C and 100 °C, respectively. However, it is vital to state that the viscosities at 100 °C of the PKO bio-lubricants samples obtained in this work were greater than that of the petroleum lubricants. As such, the synthesized PKO biolubricants exhibits greater thermal stability and can endure greater mechanical stress than petroleum lubricants.