Pyrolytic degradation

M. L. Bernard et al, CRAcadSci, Ser C, 272 (26), 2112-15 (1972) CA.75, 101675 (1971) A generalization of the previously described (Bernard et al, 1971) ablation theory (for AP) combustion to include AP-based solid propints provides satisfactory fits to the exptl data of M. Summerfield et al (1960), with reproduction of the two distinct pressure regimes observed in the combustion of AP-based powders between 0 and 100 bars. The solid binding agent is assumed to be easily pyrolyzable, with each mol producing several combustible gaseous mols, as in the case of pyrolytically degrading polymers... 

From the CGC and CGC/MS analysis of the thermally initiated reactions of HDPE and PP with DBDPO and a variety of other components reported here, it has been shown that attack of polymer chain radicals on the DBDPO is the most probable first mechanistic step in the ternary mixture pyrolytic degradation of DBDPO. 

Demirbas, A. 2005a. Hydrogen production via pyrolytic degradation of agricultural residues. Energy Sources 27 769-775. 

Finally, a few miscellaneous compounds which were identified in the Delaware River and which have not been previously reported as water contaminants will be discussed Chloro (trifluoromethyl) aniline and chloro (trifluoromethyl) nitrobenzene (no. 55 and 56) were identified in the water, they had maximum concentrations at river mile 78. Both compounds represent common sub-structures in various pesticide and dye molecules, and several of the companies located along the river have patents using these compounds (30-32j. It is possible that these compounds are actually present in the river water as such, but it is also possible that they are formed in the GC injection port by pyrolytic degradation of larger pesticide or dye molecules (see above). All three binaphthyl-sulfone isomers (no. 92) were identified in the river water near Philadelphia. Product literature for one of the companies in the area indicates production of condensed sulfonated polymers derived from naphthalene sulfonic acid and maleic anhydride. It seems likely that the binaphthylsulfones are formed as by-products during preparation of this commercial product. 

The majority of heterocyclic compounds are formed through thermal interactions of reducing sugars and amino acids, known as Maillard reactions. Other thermal reactions such as hydrolytic and pyrolytic degradation of food components (e.g. sugars, amino acids and vitamins) and the oxidation of lipids also contribute to the formation of heterocyclic compounds responsible for the complex flavor of many foodstuffs. 

By way of an early example, the effect of calcium carbonate, ATH, and MH fillers on smoke production from styrene butadiene (SBR) foams has been reported.47 It was evident that all the fillers reduced soot formation relative to unfilled foam with the hydrated fillers being more effective than the calcium carbonate, which was considered to act merely as matrix diluent. ATH and MH were found to give enhanced char formation with the promotion of solid-state cross-linking as opposed to pyrolytic degradation. An afterglow effect, occurring after the extinction of the flame, was noted with MH and attributed to the slow combustion of carbon residues. 

M. Bisi, C. Nicolella, E. Palazzi, M. Rovatti and G. Ferraiolo HCl formation via pyrolytic degradation of polyvinyl chloride (PVC) an empirical approach to kinetic modeling, Chem. Engng. Technol, 17, 67-72 (1994). 

This book provides an overview of the science and technology of pyrolysis of waste plastics. The book will describe the types of plastics that are suitable for pyrolysis recycling, the mechanism of pyrolytic degradation of various plastics, characterization of the pyrolysis products and details of commercially mature pyrolysis technologies. 

Snitable polymers (snitable in this regard means that the polymer exhibits adjnstable rheology, latent reactivity, and controllable pyrolytic degradation) are synthesized according to well-developed procedures from appropriate monomers... 

Pyrolytic degradation of esters in the vapour phase [36] occurs by a first-order unimolecular reaction... 

In this article, we summarize the basic kinetic observations and principles involved in pyrolytic degradations and present some selected and partially solved problems on reactions based on chain breakdown of vinyl-type polymers. 

In 1851, A.W. Hofmann discovered that when trimethylpropylammonium hydroxide is heated, it decomposes to form a tertiary amine (trimethylamine), an olefin (propene), and water. Widespread use of this transformation did not occur until 1881, when Hofmann applied this method to the study of the structure of piperidines and nitrogen-containing natural products (e.g., alkaloids). " The pyrolytic degradation of quaternary ammonium hydroxides to give a tertiary amine, an olefin and water is known as the Hofmann elimination. The process involves three steps 1) exhaustive methylation of the primary, secondary or tertiary amine with excess methyl iodide to yield the... 

On pyrolytic degradation, when the individual D-glucose residues are completely degraded to water, carbon dioxide, and minor volatile products to the first approximation, the reaction is... 

A study of the cumulative yields of volatile products at various temperatures showed that, after pyrolysis for 18 hours at 156 and 188°, although water was the main product from the starches, carbon dioxide and carbon monoxide were also formed. Limited, pyrolytic degradation must, therefore, have occurred at these temperatures. There was a large increase in all three products at 218.6°, indicating that major decomposition occurs near this temperature. In contrast, cellulose did not form comparable quantities of carbon dioxide and carbon monoxide until temperatures of 260-270° were reached. 

Quinoline is a high-boiling liquid isoquinoUne is a low-melting solid each has a sweetish odour. Both bases have been known for a long time quinoline was first isolated from coal tar in 1834, isoquinoUne from the same source in 1885. Shortly after the isolation of quinoline from coal tar, it was also recognised as a pyrolytic degradation product of cinchonamine, an alkaloid closely related to quinine, from which the name quinoline is derived the word quinine, in turn, derives from quina, a Spanish version of a local South American name for the bark of quinine-containing Cinchona species. 

Tab. 2 Summary of selected anthropogenic contaminants identified in the extracts of the Teltow Canal sediments as published previously (Schwarzbauer et al. 2001 Ricking et al. 2003). Compounds not identified in the non-extractable residue after application of chemical or pyrolytic degradation procedures are given in italics.

Song, C., S. Eser, H.H. Schobert, and P.G. Hatcher. Pyrolytic Degradation Studies of a Coal-Derived and a Petroleum-Derived Aviation Jet Fuel. Energy Fuels, 1993, 7 (2), 234-243. 

Balasubrahmanyam, S.N. and L.D. Quin Thermal degradation of nomicotine 15th Tobacco Chemists Research Conference, Program Booklet and Abstracts, Vol. 15, Paper No. 17, 1961, p. 9 Pyrolytic degradation of nomicotine and myosmine Tob. Sci. 6 (1962) 133-136. 

A useful SiC fiber forming precursor must offer controllable rheology, latent reactivity, controllable pyrolytic degradation, high ceramic yield, high... 

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