High-temperature heating processes for coal-tar-derived pitch (pitch A), petroleum-derived pitch (pitch B), and hydrogenated petroleum-derived pitch (pitch C) have been studied by in-situ hightemperature '"C-NMR. Mesophase formation processes have been successfully monitored for all three kinds of p
Structural analysis of mesophase pitch with high-resolution, high-temperature 13C-NMR
β Scribed by Kazuyuki Murakami; Mitsuru Okumura; Masaharu Yamamoto; Yuzo Sanada
- Publisher
- Elsevier Science
- Year
- 1996
- Tongue
- English
- Weight
- 487 KB
- Volume
- 34
- Category
- Article
- ISSN
- 0008-6223
No coin nor oath required. For personal study only.
β¦ Synopsis
The structural parameters of mesophase pitch with optical anisotropy have been successfully obtained by using high-temperature 13C-NMR spectroscopy.
Well-resolved spectra were obtained from the mesophase pitch with the addition of pyrene, which played the role of solvent for a quinolineinsoluble rich mesophase pitch during NMR measurement at 573 K. The resolution of NMR spectra was improved due to the decline in viscosity, without any influence on the chemical shift for aliphatic carbons. Hydrogen distribution has been converted from the intensities of aliphatic carbon obtained by a high-temperature 13C-NMR spectrum. Average structural parameters of whole mesophase pitch were calculated with the distribution of hydrogen by using Brown-Ladner equations. Structural characteristics of the benzene-insoluble fraction in two kinds of mesophase pitch have been discussed as well as that of the benzene-soluble fraction and whole pitch.
π SIMILAR VOLUMES
## Abstract Magic angle spinning (MAS) ^13^C NMR was employed to investigate seeds. By combining single pulse excitation (SP) and crossβpolarization (CP) experiments, we showed that both liquid and solid domains of plant seeds (__Arabidopsis thaliana, Lactuca sativa__ and __Pisum sativum__) can be