Synthesis of a New Diffusion Pump Oil from Diphenyl and α-Olefin

Abstract

A mixture of diphenyl and a-olefin (C₁₁-C₁₅ mixture) in the presence of anhydrous aluminium chloride was heated at 150°C to give a pale yellow oil boiling at 180-200°C/10^-4 Torr. This oil has an excellent properties for a diffusion pump oil, for instance, the ultimate pressure was measured by Hickman type glass diffusion pump, and we certified the order of 10^-7 Torr, as showed in Table 4, and thermal decomposition rate was also measured as shown in Table 5. which we realized this rate is comparably low.