2 Experimental Section
Poly-α-olefin (PAO, 3 cSt at 100 oC) and Di-iso-octyl sebacate (DIOS, 3 cSt at 100 oC) base oils are purchased from Shanghai Foxsyn Chemical Science and Technology Co. Ltd. and Shanghai Aladdin Biochemical Technology Co. Ltd., respectively. The 928 and 50-1-4Φ aviation lubrication oils are commercially available in the Henan Hangcai Science and Technology Co. Ltd. Antioxidants, including 2,6-butylated hydroxytoluene (T501), N-phenyl-1-naphthylamine (T531) and 4,4-diisooctanyldiphenylamine (Tz516) is purchased from Shanghai Kaiyin Chemicals Co. Ltd. A lab-designed aviation lubrication oil comparative oxidation appliance is made for the oxidation reactions of the oil samples in this paper. The base oils (PAO, DIOS) and aviation lubrication oils (928 and 50-1-4Φ) are oxidized in the designed appliance shown in Figure 1 (The detailed information of the appliance is shown in Figure 1s in SI). The experiment conditions including metal sheet, oxidation time and oxidation temperature are adjusted in oxidation reactions to produce the oil specimens with different color numbers.