Ashraf M Ashmawy, El- Sayed M Elnaggara, Doaa I Osmanb, Maher I Nessimb
Two novel azo phenols mesogenic group namely 2-sec-butyl-4-(p-tolyldiazenyl)phenyl 4-(dodecyloxy) benzoate I12a,and 4-((4-bromophenyl)diazenyl)-2-sec-butylphenyl 4-(dodecyloxy) benzoate I12b were synthesized .The prepared compound were characterized using FT-IR, 1H-NMR, Mass Spectroscopy and Elemental Analysis. Their mesophase was investigated by Differential Scanning Calorimetry (DSC). Their antioxidant efficiency for Egyptian lubricating base oil was tested via monitoring the oxidation reaction through the change in total acid number (TAN) and viscosity. The obtained results showed that, the efficiency of these compounds was ranked as follows I12a > I12b.