Pyrotechnie reaction of boron and lead monoxide: heats of reaction and differential scanning calorimetry studies

✍ Scribed by Jonathan A.C. Goodfield; Gwilym J. Rees

• Publisher: Elsevier Science
• Year: 1982
• Tongue: English
• Weight: 589 KB
• Volume: 61
• Category: Article
• ISSN: 0016-2361
• DOI: 10.1016/0016-2361(82)90313-1

✦ Synopsis

Differential scanning calorimetry (DSC) has been applied to the study of the fast reaction of boron with lead monoxide, and bomb calorimetry has been utilized to compare experimental and theoretical heats of reaction. DSC traces were obtained for PbO/B compositions (80/20,50/50 and 9713 wt?&) and also for PbO/BzOs (1 :I ) mixtures, utilizing scan rates of 5,10 and 20" min-' and conducting the measurements under an atmosphere of argon (20 ml min-'). Two well-defined exothermic peaks were obtained in the DSC traces and analysis of the data, together with examination of infrared spectra, indicated the presence of BzOs and Pb in the reaction products. The excess heat outputs, at PbO levels above the stoichiometric level, are explained by the exothermic reaction of PbO with BzOs to form clear, slightly yellow glasses. The formation of a surface-coating of BzOs on the boron particles has an important effect on the rate of the main PbO-B reaction.