Akademik Veri Yönetim Sistemi
ENERGY & FUELS, cilt.13, sa.5, ss.1030-1036, 1999 (SCI-Expanded)
This paper describes different procedures applied for the preparation of stabilized fibers from Avgamasya asphaltite products. Three different methods of solvent extraction, vacuum distillation of fluidized bed pyrolysis tar, and air blowing of the vacuum distilled products were used in this study. The asphaltite pitches obtained by different methods are characterized by various techniques such as elemental analysis, thermogravimetric analysis (TGA and DTG), softening point (SP), Fourier transform infrared spectroscopy (FT-IR), and solution H-1 and C-13 nuclear magnetic resonance (NMR) spectroscopy. Structural characterization by elemental analysis, FTIR, and nuclear magnetic resonance spectroscopy on both vacuum-distilled and air-blown pitches showed that distillation of lighter fractions, reduction of atomic WC ratio, and dehydrogenation raised their softening points. Structural analysis by NMR showed that asphaltite pitches consist of condensed aromatic rings combined with methylene bridges and heterocyclic groups, and substituted with alkyl and naphthenic groups. Asphaltite pitches which were prepared by solvent extraction (HI-BS) and vacuum distillation (AVD3) resulted in very good and medium spinnable green fibers, respectively. On the other hand, air-blown pitches could not be spun. The morphology of the stabilized fibers was studied by scanning electron microscopy (SEM).