Determination of Polymer Type and Comonomer Content in Polyethylenes by Pyrolysis−Photoionization Mass Spectrometry

Zoller, David L.; Sum, Stephen T.; Johnston, Murray V.; Hatfield, Galen R.; Qian, Kuangnan

doi:10.1021/ac9807159

Cited by 31 publications

(31 citation statements)

References 25 publications

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“…Each graph in these figures is a plot of signal intensity of the m/z of interest normalized by the total intensity of all ions in the spectrum versus HAB. Normalized intensities are highly reproducible with the photoionization technique [38][39][40]. Representative aliphatic peaks corresponding to methyl (CH 3 , 15 m/z), ethyl (C 2 H 5 , 29 m/z), butadiene (C 4 H 6 , 54 m/z), and octene (C 8 H 16 , 112 m/z) are shown in Fig.…”

Section: Mass Spectramentioning

confidence: 96%

Chemical species associated with the early stage of soot growth in a laminar premixed ethylene–oxygen–argon flame

Öktem

Tolocka

Zhao

et al. 2005

Combustion and Flame

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175

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Section: Mass Spectramentioning

confidence: 96%

Chemical species associated with the early stage of soot growth in a laminar premixed ethylene–oxygen–argon flame

Öktem

Tolocka

Zhao

et al. 2005

Combustion and Flame

Self Cite

175

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“…VUV-SPI is a soft ionization technique that can be adjusted to be nearly fragmentation free. Thus, recently VUV-SPI-TOFMS has been applied to diagnose several systems such as automobile exhaust gas, [3][4][5][6] pyrolysis of polymers [7][8][9][10][11] and coals, 12 flue gas, 13,14 cigarette smoke, 11,[15][16][17] silicon chemical vapor deposition, [18][19][20][21][22] and aerosol particles. 23 A coherent VUV laser light at 10.5 eV (118 nm) generated by a frequency tripling of the third harmonics (355 nm) of a Nd:YAG laser is a good photoionization light source due to the easy generation and high intensity.…”

Section: Introductionmentioning

confidence: 99%

Vacuum Ultraviolet Photoionization Mass Spectra and Cross-Sections for Volatile Organic Compounds at 10.5 eV

Kanno

Tonokura

2007

Appl Spectrosc

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Vacuum ultraviolet single-photon ionization time-of-flight mass spectrometry (VUV-SPI-TOFMS) has been applied to the detection of volatile organic compounds (VOCs), including aromatic, chlorinated, and oxygenated compounds. Photoionization mass spectra of 23 VOCs were measured using SPI-TOFMS at 10.5 eV (118 nm). The limits of detection of VOCs using SPI-TOFMS at 10.5 eV were estimated to be a few ppbv. The mass spectra of 20 VOCs exhibit only the parent ion and its isotopes' signals. The ionization processes of the VOCs were discussed on the basis of the reaction enthalpies predicted by the quantum chemical calculations. Absolute photoionization cross-sections for 23 VOCs, including 12 newly measured VOCs, at 10.5 eV were determined in comparison to the reported absolute photoionization cross-section of NO.

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“…Gorin postulated (6) that the catalyst is participating in the hydrogenation of naphthalene produced from the tetralin and reports in the literature have shown that in catalytic liquefaction the amount of naphthalene produced from tetralin decreases compared with the liquefaction in the absence of catalyst (14)(15)(16). From Table 2, we can see the amounts of tetralin and naphthalene in the liquid product from catalytic and noncatalytic liquefaction and we do not observe the decrease in naphthalene in the product for catalytic liquefaction.…”

Section: Resultsmentioning

confidence: 56%

Study of Solvent and Catalyst Interactions in Direct Coal Liquefaction

Klein¹

2000

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Executive SummaryTo provide a better understanding of the roles of a solid catalyst and the solvent in Direct Coal Liquefaction, a small reactor was equipped with a porous-walled basket which was permeable to the solvent but was not permeable to the cod or solid catalyst.With this equipment and a high volatile bituminous coal it was found that direct contact between the catalyst in the basket and the coal outside the basket is not required for catalyzed coal liquefaction. The character of the solvent in this system makes a significant difference in the conversion of the coal, the better solvents being strong donor solvents.Because of the extensive use of thermogravimetric analysis in this laboratory, it was noted that the peak temperature for volatiles evolution from coal was a reliable measure of coal rank. Because of this observation, a variety of coals of a range of ranks was investigated. It was shown in this work that measuring the peak temperature for volatiles evolution was a quite precise indicator of rank and correlated closely with the rank value obtained by measuring vitrirlite reflectance, a more difficuit measurement to make.This prompted the desire to know the composition of the volatile material evolved as a function of coal rank. This was then measured by coupling a TGA to a mass spectrometer using laser activation and photoionization detection TG-PI-MS. The predominant species in volatiles of low rank coal turned out to be phenols with some alkenes. As the rank increases. the relative amounts of alkene and aromatic hydrocarbons increases and the oxyge actually pyrolytic products and not volatilization products of the cod. d species decrease. It was shown that se volatiles were Solvent extraction experiments coupled with Thennogravimetric-photoionizationmass sp+ctrometry (TG-PI-MS) indicated that the low boiling and more extractable material w essentially similar in chemical types to the non-extractable portions but apparently higher molecular weight and therefore less extractable. IntroductionDespite many years of research on Direct Coal Liquefaction, there are still some aspects of the process which are not fully understood and yet could have important implications for process improvement. Among these questions are the roles of the solid catalyst and the solvent. Seavel(1) showed that hydroaromatic solvents in direct liquefaction in the absence of a catalyst act primarily as a donor of hydrogen atoms to the free radicals formed as the coal is broken down thermally under coal liquefaction conditions. This minimizes degradative reactions of these radicals which otherwise form insoluble and unreactive products. Much emphasis in modem coal liquefaction studies however has been on liquefaction in the presence of both a donor solvent and a solid catalyst such as nickeUmoiybdenum or cobaitlmolybdenum on an alumina support.Tomlison (2) and others (3.4) have shown that adding a solid catalyst'in coal liquefaction produced higher conversion and oil yields of higher quality. Weller and Pelipetz ( 5 ) als...

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Determination of Polymer Type and Comonomer Content in Polyethylenes by Pyrolysis−Photoionization Mass Spectrometry

Cited by 31 publications

References 25 publications

Chemical species associated with the early stage of soot growth in a laminar premixed ethylene–oxygen–argon flame

Chemical species associated with the early stage of soot growth in a laminar premixed ethylene–oxygen–argon flame

Vacuum Ultraviolet Photoionization Mass Spectra and Cross-Sections for Volatile Organic Compounds at 10.5 eV

Study of Solvent and Catalyst Interactions in Direct Coal Liquefaction

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