Chemistry Reference
In-Depth Information
Table 11.5 HFRR data showing the average ball wear scar diameter, the disk wear
scar width and length on the x-axis, the film percentage, and the
coecient of friction (COF) for moringa and other vegetable oils.
(Reproduced with kind permission from Springer Science and
Business Media from Springer / Journal of Thermal Analysis and
Calorimetry, 96(3), 2009, 999-1008. Lubricant properties of Moringa oil
using thermal and tribological techniques. B.K. Sharma, U. Rashid,
F. Anwar, and S.Z. Erhan, Table 5.)
Disk wear scar
width on the
x-axis/mm
Disk wear scar
length on the
x-axis/mm
Ball wear scar
diameter/mm
Sample
Film/% COF
Moringa oil
156
217
1144
97
0.092
Jatropha oil
146
204
1168
97
0.096
Cottonseed oil
202
253
1142
95
0.097
Canola oil
149
173
1202
94
0.076
Sunflower oil
151
192
1134
95
0.069
moringa and other vegetable oils are shown in Table 11.5. With moringa oil,
the ball scar diameter was 156 mm, which is similar to other vegetable oils.
This high wear scar diameter for cottonseed oil may be due to the low
amount of free fatty acids (FFAs) present in it. Jatropha oil provided the
lowest wear scar diameter, which may be due to the presence of a higher
amount of FFAs present in it. The disk x-scar results were also similar, with
the biggest scar width being for cottonseed oil. The average COF was higher
(0.09) for moringa, jatropha and cottonseed oils, followed by canola oil
(0.076) and was the least for sunflower oil (0.07). The lower COFs in sun-
flower and canola oil may be due to their higher viscosities compared to
other oils. Despite the higher COF for moringa oil, no decrease was observed
in the average lubricant film percentage. An attempt was made to see the
effect of various groups of FAs, i.e., SFAs, UFAs, MUFAs, and PUFAs on the
lubricity properties of these oils. The COF was found to have a good cor-
relation with the amount of SFA (R
2
¼
0.85) and UFA (R
2
¼
0.89). This cor-
relation shows that a low amount of SFAs and high amount of UFAs results
in a low COF. A high amount of UFAs and a low amount of SFAs may be the
reason for the lower COFs in the case of canola and sunflower oil. More
studies are needed to confirm this observation. These results show that the
lubricity properties of moringa oil are on a par with those of other
vegetable oils.
11.4 Conclusions
In this chapter we have discussed the properties of soybean oil and how its
oxidative stability and cold-flow properties can be improved either using
genetically modified oils (HOSBO), or chemically modifying soybean oils to
ESO and CMSBOs and then using these as basestocks for lubricant formu-
lations. Use of chemical additives made further improvements in important
