After the measurement of the residual antioxidants of the oxidized oil
samples, the oxidized oil samples were testing for their residual
initial oxidation temperature (IOT, shown in Table 2). It is easy to
find the residual IOT values decrease with decreasing residual
antioxidants for their antioxidation ability gradually decreased. At the
same time, the color number of the oxidized fully formulated aviation
oil samples (Figure 2s) dramatically increased for the rapidly
increasing color-related-oxidation-products shown in Table 1. As
discussed above, most color-related-oxidation-products are generated
from the reaction of antioxidants.
Table 3 The total acid number of the 928 and 50-1-4ะค aviation
lubrication oil samples oxidized for 2 hours (mgKOH/g)