Abstract
Molecular beam mass-spectrometry was used to study the structure of a premixed H2/O2/Ar (0.26/0.13/0.61) flame with and without additives (0.1–1.1% DMMP) stabilized on a flat-flame burner at 43–80 Torr(burner temperature 95°C). The behavior of DMMP in the flame has been studied. Mass spectra of samples taken from flames, and intensity profiles of peaks 18 (H20), 32(O2),40(Ar),47(PO), 63(PO2), 647(HOPO), 80,94, 110, 124(DMMP) amu have been measured as a function of the distance from the burner surface to the sampling probe using a quadrupole mass-spectrometer and electron impact ionization at 12.1–21.6 eV with a spread of electron energy ±0.25 eV. Intensity profiles of masses 110,94,80 pass through a maximum. This shows that the species responsible for these masses are intermediates. PO(CH3)(OCH)(OH), P2(OCH3) are possible intermediates. The profile of the temperature in the flame has been determined by using a Pt-PtRh(1O%) thermocouple covered by Ceramobond 569. The effect of promotion on the H2/O2//Ar flame by the additive DMMP has been observed. The possible detailed chemical mechanism of the destruction of DMMP is presented.