Investigations on the cross-linking of binder pitch matrix of carbon bodies with molecular oxygen — Part I. Chemistry of reactions between pitch and oxygen

✍ Scribed by Th. Metzinger; K.J. Hüttinger

• Publisher: Elsevier Science
• Year: 1997
• Tongue: English
• Weight: 862 KB
• Volume: 35
• Category: Article
• ISSN: 0008-6223
• DOI: 10.1016/s0008-6223(97)00038-9

✦ Synopsis

The reactivity between a petroleum pitch (Ashland A 240) and oxygen was studied at 1 MPa oxygen pressure and temperatures between 200 and 280°C using thin pitch films. After oxidation the pitch was analyzed by FT-IR and XPS with respect to the formation of oxygen-containing functional groups. A green mix shaped into cylindrical bodies was treated with oxygen for various times for the determination of oxygen-containing functional groups by pyrolysis gas analysis. These and some additional results by DSC and ESR were used to develop reaction schemes. We have distinguished between ( 1) the formation of oxygen-containing functional groups (hydroxyl, carbonyl, carboxyl);

(2) cross-linking reactions between oxygen-containing functional groups, both occurring with liberation of water only, and ( ) cross-linking reactions by formation of C-C bonds induced by decomposition of oxygen-containing functional groups and typically accompanied by formation of CO2 and CO. The latter result indicates that oxygen-containing functional groups only affect an intermediate stability of volatile Ditch molecules UD to temoeratures at which C-C bonds can be formed in the pyrolysis.