Decomposition products of N,N '-disalicylidene-1,2-propanediamine adsorbedon 304 stainless steel

The compound, N,N'-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 (M DA) in thermally stressed jet fuel has raised questions on whether it decom poses after coming into contact with hot metal surfaces within the aircraft fuel system. Temperature programmed desorption (TPD) was performed to dete ct decomposition products of MDA on the 304SS surface. A method of scanning a relatively large mass range during desorption was developed to acquire S -dimensional contour TPD (CTPD) plots of adsorbed species on the surface. C ompounds with molecular masses of 107, 133, 232 and 290 were detected and t heir structures proposed. Conventional TPD spectra of selected molecular ma sses were then taken as a function of exposure. Mechanistic pathways for de composition of MDA and formation of new compounds on the surfaces are propo sed. (C) 1999 Elsevier Science B.V. All rights reserved.