Carbon fibers from mixtures of AR and supercritically extracted mesophases

Beauharnois, Mark E.; Edie, D.D.; Thies, Mark C.

doi:10.1016/s0008-6223(01)00045-8

Cited by 35 publications

(26 citation statements)

References 9 publications

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“…Furthermore, over the entire range of measured pressures, yields with a +DT are in the 5-25 % range, i.e. conditions that produce bottom products with softening points desired for processing into carbon materials [2,4].…”

Section: Effect Of Solvent Power On Yield and Compositionmentioning

confidence: 99%

“…Potential and existing uses for these materials include activated carbon fibers and high thermal conductivity carboncarbon composites [1,2]. Petroleum pitches are produced by the thermal polymerization of an aromatic oil feedstock; thus, they are oligomeric in nature and consist of a molecular weight distribution (MWD) of polycyclic aromatic hydrocarbons, with methyl and naphthenic substitution commonly occurring [3,4].…”

Section: Introductionmentioning

confidence: 99%

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Control of the Molecular Weight Distribution of Petroleum Pitches via Dense‐Gas Extraction

Cervo

Thies

2007

Chem Eng & Technol

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Dense-gas extraction (DGE) was used to fractionate an isotropic petroleum pitch (number-average molecular weight M n = 516) into oligomeric cuts. A countercurrent-flow packed column was used to effect the separation, with supercritical toluene being used as the dense-gas solvent and commercially available M-50 or A-240 pitch being used as the feed. Isothermal operation at 330, 350, and 380°C was investigated, as well as operation with a linear positive temperature gradient (+DT), with the bottom of the column at 330 and the top at 380°C. For isothermal operation, the molecular weight distribution of the bottom products consisted primarily of dimer (M n = 508) and trimer (M n = 759) species, with pressure changes of as little as 5 bar producing significant changes in their relative distribution, as observed by MALDI mass spectrometry. On the other hand, by operating with a +DT, we could produce a bottom product consisting primarily of trimers and tetramers (M n = 997).

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Section: Effect Of Solvent Power On Yield and Compositionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Control of the Molecular Weight Distribution of Petroleum Pitches via Dense‐Gas Extraction

Cervo

Thies

2007

Chem Eng & Technol

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“…Such pitches can serve as raw materials for a wide range of carbon products, including carbon electrodes, carbon fibers for fuel cell substrates, high thermal conductivity carbon fibers, and the matrix phase of carbon-carbon composites [3][4][5]. Researchers have long recognized the important role that mol wt and structure play in the suitability of a given pitch for a particular application [1,3,5], but to date this understanding is primarily qualitative because of an inability to isolate and properly characterize the constituents of pitch.…”

Section: Introductionmentioning

confidence: 99%

The Molecular Design of High-Performance Carbon Materials

Thies¹

2008

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“…These pitches can serve as precursors for a wide variety of carbon products, including carbon electrodes, [5] high thermal conductivity carbon fibers, [6] and carbon-based composites. [7] Control of the MWD of pitches is desirable, as it can induce significant changes in their bulk properties and performance characteristics.…”

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confidence: 99%

Quantitative analysis of polydisperse systems via solvent‐free matrix‐assisted laser desorption/ionization time‐of‐flight mass spectrometry

Kulkarni

Thies

2012

Rapid Comm Mass Spectrometry

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Quantitative analysis of partially soluble and insoluble polydisperse materials is challenging due to the lack of both appropriate standards and reliable analytical techniques. To this end, matrix-assisted laser desorption/ionization mass spectrometry (MALDI-MS) incorporating a solvent-free sample preparation technique was investigated for the quantitative analysis of partially soluble, polydisperse, polycyclic aromatic hydrocarbon (PAH) oligomers. Molecular weight standards consisting of narrow molecular weight dimer and trimer oligomers of the starting M-50 petroleum pitch were produced using both dense-gas/supercritical extraction (DGE/SCE) and preparative-scale, gel permeation chromatography (GPC). The validity of a MALDI-based, quantitative analysis technique using solvent-free sample preparation was first demonstrated by applying the method of standard addition to a pitch of known composition. The standard addition method was then applied to the quantitative analysis of two insoluble petroleum pitch fractions of unknown oligomeric compositions, with both the dimer and trimer compositions of these fractions being accurately determined. To our knowledge, this study represents the first successful MALDI application of solvent-free quantitative analysis to insoluble, polydisperse materials.

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Carbon fibers from mixtures of AR and supercritically extracted mesophases

Cited by 35 publications

References 9 publications

Control of the Molecular Weight Distribution of Petroleum Pitches via Dense‐Gas Extraction

Control of the Molecular Weight Distribution of Petroleum Pitches via Dense‐Gas Extraction

The Molecular Design of High-Performance Carbon Materials

Quantitative analysis of polydisperse systems via solvent‐free matrix‐assisted laser desorption/ionization time‐of‐flight mass spectrometry

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