Pyrolysis characterization

Pyrolysis results are summarized in Table I, parts a, b, and c of which respectively concern substrate characterization, pyrolysis conditions, and product yields. 

HPSEC may be used to characterize pyrolysis oils obtained from different sources, and comparisons may be drawn regarding their... 

HPSEC has been shown to be a useful method of characterizing pyrolysis oils because it examines the whole of the oil. When... 

Analytical investigations may be undertaken to identify the presence of an ABS polymer, characterize the polymer, or identify nonpolymeric ingredients. Fourier transform infrared (ftir) spectroscopy is the method of choice to identify the presence of an ABS polymer and determine the acrylonitrile—butadiene—styrene ratio of the composite polymer (89,90). Confirmation of the presence of mbber domains is achieved by electron microscopy. Comparison with available physical property data serves to increase confidence in the identification or indicate the presence of unexpected stmctural features. Identification of ABS via pyrolysis gas chromatography (91) and dsc ((92) has also been reported. 

Oxychlorination of Ethylene. When compared with direct chlorination, the oxychlorination process is characterized by higher capital investment, higher operating costs, and slightly less pure EDC product. However, use of the oxychlorination process is dictated by the need to consume the HCl generated in EDC pyrolysis. 

Flash vacuum pyrolysis of 2-methoxycarbonylpyrrole (11) gives the ketene (12), characterized by IR absorption at 2110 cm. On warming to -100 to -90 °C the dimer (13) is formed (82CC360). Flash vacuum pyrolysis of indole-2-carboxylic acid (14) results in loss of water and the formation of a ketene (15) showing absorption at 2106 cm (82CC360). 

Figure 12.8 Mia ocolumn size exclusion chromatogram of a styrene-aaylonitrile copolymer sample fractions ti ansfeired to the pyrolysis system are indicated 1-6. Conditions fused-silica column (50 cm X 250 p.m i.d.) packed with Zorbax PSM-1000 (7p.m 4f) eluent, THF flow rate, 2.0 p.L/min detector, Jasco Uvidec V at 220 nm injection size, 20 nL. Reprinted from Analytical Chemistry, 61, H. J. Cortes et al, Multidimensional chromatography using on-line microcolumn liquid chromatography and pyrolysis gas chromatography for polymer characterization , pp. 961 -965, copyright 1989, with peimission from the American Chemical Society.

Figure 12.9 Typical pyrolysis chromatogram of fraction from a styrene-acTylonitiile copolymer sample obtained from a miciocolumn SEC system 1, acrylonitrile 2, styrene. Conditions 5 % Phenylmetliylsilicone (0.33 p.m df) column (50 m X 0.2 mm i.d.) oven temperature, 50 to 240 °C at 10 °C/min carrier, gas, helium at 60 cm/s flame-ionization detection at 320 °C make-up gas, nitrogen at a rate of 20 mL/min. P indicates tlie point at which pyrolysis was made. Reprinted from Analytical Chemistry, 61, H. J. Cortes et ai, Multidimensional cliromatography using on-line microcolumn liquid cliromatography and pyrolysis gas cliromatography for polymer characterization , pp. 961-965, copyright 1989, with permission from tlie American Chemical Society.

H. J. Goites, G. L. Jewett, G. D. Pfeiffer, S. Martin and G. Smith, Multidimensional cliromatography using on-line microcolumn liquid cliromatography and pyrolysis gas cliromatography for polymer characterization . Awn/. Chem. 61 961-965 (1989). 

The combination of the flash vacuum pyrolysis (FVP) technique169 with mass spectrometry proved to be particularly useful in identification and characterization of both the fragmentation/rearrangement patterns, intermediates and/or final products formed (see Section IV.E.l). Usually, no structures are indicated in the mass spectra, although ionization and appearance potential can, in principle, provide structural information. 

Isotropic carbon is obtained by the pyrolysis of a hydrocarbon, usually methane, at high temperature (1200-1500°C) in a fluidized bed on a graphite substrate.Under these conditions, a turbostratic structure is obtained which is characterized by very little ordering and an essentially random orientation of small crystallites. In contrast to graphite which is highly anisotropic, such a structure has isotropic properties (see Ch. 7). Isotropic carbon is completely inert biologically. Its properties are compared to alumina, another common implant material, in Table 17.8. Notable is its high strain to failure. 

MacKay, J. J. Dimmel, D. R. Boon, J. J. Pyrolysis MS characterization of wood from CAD-deficient pine. J. Wood Chem. Technol. 2001, 21, 19-29. 

Mass Spectrometry. Mass spectrometric (MS) analysis has been utilized for polymer and copolymer structural identification. Recently Dussel et al. utilized pyrolysis-MS to characterize... 

Eudy, L. W. Analytical pyrolysis and derivatization methods combined with gas chromatography-mass spectrometry for the characterization of bacteria and other nonvolatile materials. Univ. South Carolina, Columbia, SC, USA (1983), 197 pp. From Diss. Abstr. Int. B 1984, 45(1), 171. 

Smith, P B. Snyder, A. E Characterization of bacteria by quartz tube pyrolysis-gas chromatography/ion trap mass spectrometry. J. Anal. Appl. Pyrolysis 1992, 24, 23-38. 

METHOD REPRODUCIBILITY AND SPECTRAL LIBRARY ASSEMBLY FOR RAPID BACTERIAL CHARACTERIZATION BY METASTABLE ATOM BOMBARDMENT PYROLYSIS MASS SPECTROMETRY... 

Goodcare, R. Characterization and quantification of microbial systems using pyrolysis mass spectrometry Introducing neural networks to analytical pyrolysis. Microbiol. Europe 1994, 2,16-22. 

Wilkes, J. G. Rushing, L. Nayak, R. Buzatu, D. A. Sutherland, J. B. Rapid phenotypic characterization of Salmonella enterica strains by pyrolysis metastable atom bombardment mass spectrometry with multivariate statistical and artificial neural network pattern recognition. J. Microbiol. Meth. submitted for publication. 

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