Comparative study of the chemical structure of the disk-like components in the quinoline insolubles

Microstructural Characterization of Next Generation Nuclear Graphites

“…QI particles are basically solid particles similar to carbon black, composed of high-molecular-weight hydrocarbons (Mochida et al, 1978; Peaden et al, 1980). These are formed either during the decomposition of coal or through the condensation of small aromatic molecules on the walls of the cracking chamber.…”

Disclination Structures in the Carbonaceous Mesophase

“…There is no point-to-point registry between adjacent molecules. This model suggests the stacking, size, and possible shapes of the disklike molecules, which may be quite irregular and contain vacant sites or holes [6], The symmetry elements of the carbonaceous mesophase are (1) any translation, (2) any rotation about an axis normal to the molecules, and (3) a rotation of π about any axis parallel to the plane of the molecules.…”

“…Mochida et al [6] analyzed mesophase spherules prepared by pyrolysis of the quinoline-soluble fraction of a petroleum pitch; the weights of the constituent molecules ranged from 400 to 3000, with a number-average molecular weight near 1400. Infrared spectroscopy, nuclear magnetic resonance spectroscopy, and vapor-pressure osmometry can be used to estimate the structural configuration of the disklike aromatic molecules in the carbonaceous mesophase.…”

“…At 22°C, χ,, = -0.50 X 10^6 emu/g χ ± = -1.19 X 10~6 emu/g Xa = X± ~ Χ» = -0.69 X 10" 6 emu/g where χ ± and %| are the diamagnetic susceptibilities measured with the magnetic field perpendicular and parallel to the aromatic molecules, respectively, and Xa is the diamagnetic anisotropy. Delhaes et al concluded that for disklike molecules with a molecular weight about 1000 and a carbon-to-hydrogen atomic ratio of 1.6, the molecules must be open structures, i.e., large molecules with smaller aromatic regions as proposed by Mochida et al [6] (Fig. Delhaes et al concluded that for disklike molecules with a molecular weight about 1000 and a carbon-to-hydrogen atomic ratio of 1.6, the molecules must be open structures, i.e., large molecules with smaller aromatic regions as proposed by Mochida et al [6] (Fig.…”

Modification of isotropic carbon fibre precursor with PVC using tetraline as a solvent

“…The principal constituent molecules of precursor pitch for carbon fibre are disc-like aromatic compounds, since it is usually prepared from aromatic pitch materials by heat treatment [1,2]. Such a structural characteristic causes several problems in the production of pitch-based carbon fibre.…”