ABSTRACT
The softeners most widely used by compounders are undoubtedly petroleum oils. Fundamentally, rubber processing oils are high boiling fractions obtained in refining after gasoline, fuel oil, and other low boilers are removed by distillation. Since the composition of an oil has an effect on the properties of the rubber compound in which it is included, various identification methods have been developed. Two major analytical methods are used: molecular and carbon-type analysis. There are two main considerations in choosing a petroleum oil as a softener or plasticizer: its effect on processing behavior and its effect on vulcanizate properties. The viscosity of an oil is of concern to the compounder with respect to handling and the properties it imparts. Pour point values of petroleum oils are most often considered in relation to an oil's ability to lubricate well under low temperature conditions.
