Abstract
Although petroleum oils continue to be the dominant type of base stock for the formulation of vaporizable quenchants, there is increasing pressure to identify an alternative. Petroleum oils are not a renewable base stock, and they possess generally poor toxicity and biodegradability properties. Currently, the most often cited alternative base stocks are those based on seed oils since they are renewable and are readily biodegradable, and usually non-toxic. However, they suffer a critically important deficiency in that they are also typically much less stable to thermal-oxidative degradation than petroleum oils. Various studies have addressed the effect of vegetable oil structure on oxidation and on the use of oxidation inhibitors to provide the necessary stabilization. However, most of these reports do not address the relative effects of specific antioxidant structures on inhibiting oxidation and on quenching performance. This paper describes the use of certain antioxidant structures on inhibition of thermal-oxidation and on the effect of the presence of antioxidants on quenching performance.
