Oxidative stabilisation of synthetic fluids and vegetable oils

The use of ashless antioxidants to increase the useful working life of synthetic fluids, such as polyalphaolefins, polyalkylene glycols and carboxylic acids, is discussed, and some general guidelines are proposed. The application of ashless antioxidants in controlling the oxidative degradation of several different types of biodegradable vegetable oil is illustrated. The action of the naturally occurring antioxidant, vitamin E, in some of these fluids has been examined and some preliminary results are reported.