Action mechanism of antioxidation and anticorrosion and molecular design for perfluoropolyether fluid additives (I)

Abstract

Three kinds of the antioxidation and anticorrosion additives from the N-substituted perfluoropolyalkylether phenylamide (PFPEA) were selected and synthesized. UV and IR spectral analyses were carried out, and strong absorption peaks of UV from benzene ring are about 240.7, 215.4 and 230.1 nm, respectively. The characteristic peaks of IR from the C=O are about 1713.9, 1712.2 and 1710.8 cm-1, respectively. The antioxidant and anticorrosive property was tested for the three synthesized additives. The results show that the weight loss of lubrication oil can decrease by 1/7, 1/9 and 1/25 respectively after adding synthesized additives. The thermal decomposition temperature(TD) in the presence of Al2O3 can increase by 19–22°C. From theoretic and experimental study it indicates that the PFPEAs with nitrogen heteroatom not only accepts electron from perfluoropolyalkylether oxygen radical (RfO.) to form a stable adduct and to prevent RfO. decomposing further, but also donates electron to form chemical adsorption film and to protect metal from corrosion. These additives have shown the better property of the antioxidation and anticorrosion. An electron-releasing group, or phenyl group, introduced to the N-atom of this kind of compound can improve the antioxidant and anticorrosive efficiency of the additives.