Decomposition products of N,NX-disalicylidene-1,2-propanediamine adsorbed on 304 stainless steel

The compound, N,NX-disalicylidene-1,2-propanediamine, is commonly added to jet fuels to counteract the catalysis of thermally induced autoxidation by certain dissolved metals. The behavior of the metal deactivator additive MDA.in thermally stressed jet fuel has raised questions on whether it decomposes after coming into contact with hot metal surfaces within the aircraft fuel system. Temperature programmed desorption TPD.was performed to detect decomposition products of MDA on the 304SS surface. A method of scanning a relatively large mass range during desorption was developed to acquire 3-dimensional contour TPD CTPD.plots of adsorbed species on the surface. Compounds with molecular masses of 107, 133, 232 and 290 were detected and their structures proposed. Conventional TPD spectra of selected molecular masses were then taken as a function of exposure. Mechanistic pathways for decomposition of MDA and formation of new compounds on the surfaces are proposed. q1999 Elsevier Science B.V. All rights reserved.