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Metallurgical and Materials Transactions B-Process Metallurgy and Materials Processing Science


The chemistry surrounding the pyrolysis of N,N'-ethylenebisstearimide (EBS) compacted with iron powder is described for the first time. Heat treatment is carried out in a 5 vol pct hydrogen atmosphere (balance nitrogen) over the 100°C to 850°C range. The exhaust from the furnace is monitored by Fourier transform infrared and dispersive ultraviolet absorption spectroscopy; condensable materials are analyzed by gas chromatography/mass spectrometry (GC/MS). A wide range of analytes emitted from the preceding process were characterized. The aliphatic CH stretch in the 3000 to 2700 cm-1 range and the asymmetric CO stretch in gaseous CO2 at 2350 cm-1 are excellent indicators of the extent of delubrication. A bimodal CO emission phase is observed in the temperature window between delubrication and sintering. Three major large molecule reaction products, along with five minor compounds, are identified by GC/MS. A preliminary reaction mechanism is inferred based on product analysis and known organic chemistry. It appears that hydrolysis of EBS competes with γ-H abstraction yielding an N-vinyl amide and stearamide, which undergoes further reaction. Hydrolysis affords stearic acid, which decarboxylates. to heptadecane, and 2-heptadecyl-4,5-dihydroimidazole via ring closure of the corresponding amino-amide.





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Copyright 2004, ASM International. This paper was published in Metallurgical and Materials Transactions B-Process Metallurgy and Materials Processing Science Vol. 35 Iss. 2 pp. 381-392 and is made available as an electronic reprint with the permission of, ASM International. One print or electronic copy may be made for personal use only. Systematic or multiple reproduction, distribution to multiple locations via electronic or other means, duplications of any material in this paper for a fee or for commercial purposes, or modification of the content of this paper are prohibited.