Mechanism and chemical inhibition of the pentaborane oxidation reaction

✍ Scribed by A.D. Snyder; D.L. Zanders; G.B. Skinner

• Publisher: Elsevier Science
• Year: 1965
• Tongue: English
• Weight: 440 KB
• Volume: 9
• Category: Article
• ISSN: 0010-2180
• DOI: 10.1016/0010-2180(65)90090-8

✦ Synopsis

The objective of this work has been to learn how to inhibit chemically the pentaborane-oxygen reaction with a view to developing improved fire protection systems. Rates of pyrolysis of pentaborane and ignition induction times of pentaborane-oxygen-argon mixtures were measured in a shock tube at 520 ° to 860°K. The effects of pressure, mixture ratio and a variety of additives on the flame speed of the pentaborane-air system were studied employing a low-pressure burner. Pyrolysis of pentaborane was shown to be the rate-controlling step in the ignition process, since induction times were found to be independent of oxygen concentration. Butadiene, toluene and benzene were found to be most effective in reducing flame ,speed and in lengthening ignition induction times. The order of inhibitor effectiveness on the flame reaction bears a close resemblance to that of the hydrogen-air and diborane-air flame systems, indicating that flame propagation in the borane-air system proceeds by a mechanism resembling, to some extent, that of the hydrogen-oxygen reaction. It is proposed that the inhibitors ]unction by removal of hydrogen atoms from the pre-flame zone.