An NMR method for quantitative determination of the carbonaceous mesophase content of a petroleum pitch

✍ Scribed by T.J. Parks; L.F. Cross; L.J. Lynch

• Publisher: Elsevier Science
• Year: 1991
• Tongue: English
• Weight: 747 KB
• Volume: 29
• Category: Article
• ISSN: 0008-6223
• DOI: 10.1016/0008-6223(91)90170-n

✦ Synopsis

Quantitative measurements of the carbonaceous mesophase content of a petroleum pitch, Ashland 240, have been achieved using high-temperature pulsed proton nuclear magnetic resonance ('H NMR) spectroscopy. A simple signal analysis procedure allows the anisotropic (mesophase) and isotropic phases of the pitch to be distinguished quantitatively. When pitches containing various proportions of mesophase were analysed by the lH NMR method and by an optical point counting method, a one-to-one correspondance was observed between the mesophase contents obtained by the two methods. This one-to-one correspondance between determinations by optical and NMR methods confirms the results of preliminary studies with a coal-based pitch. The NMR technique is more rapid and convenient than currently used optical methods of mesophase determination for monitoring and analysing the progress of mesophase development in such pitches.