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| Titel: |
PERCENTAGE AROMATIZATION AND CYCLIZATION MASS-LOSSES IN A PAN-PRECURSOR USED AS A HOLLOW-FIBER CARBON MEMBRANE-III |
| Auteur: |
Sanderson, R. D. Sadiku, E. R. |
| Verschenen in: |
International journal of polymeric materials |
| Paginering: | Jaargang 53 (2004) nr. 3 pagina's 261-281 |
| Jaar: |
2004-03 |
| Inhoud: |
Hollow-fiber carbon membranes were produced by the pyrolysis of acrylonitrile-based precursors that were spun using a wet phase-inversion technique. The fibers were used in the catalytic conversion of cyclohexane. Thermogravimetric (TGA) and variance analyses were carried out on the fibers produced. The TGA analyses involved the determination of the percentage aromatization and cyclization mass-losses as functions of process variables, such as polymerization temperature, monomer concentration, stirrer speed and initiator concentration. An empirical approach was adopted that employed statistical experimental designs that were used to recognize analytical and statistical methods that translated the process responses into comprehensible terms. A low methylcrylate (MA) concentration and a high azo-bis-isobutyronitrile (AIBN) concentration yielded a polymer that resulted in a precursor with low mass loss during carbonization. Both high AIBN concentration and low stirrer speed on the one hand and a high polymerization temperature at a low stirrer speed on the other hand yielded a low mass loss. The response plot function of the percentage mass loss indicated that a low MA concentration at a low polymerization temperature would give the lowest mass loss. Chemical shrinkage, corresponding to the cyclization process, started only at temperatures ≈200°C, while the aromatization process commenced above 350°C. |
| Uitgever: |
Taylor & Francis |
| Bronbestand: |
Elektronische Wetenschappelijke Tijdschriften |
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