Microstructural Control of Laminated Compounds by the Modification of Pitches at Low Temperatures

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Precise evaluation on iodine-treated pitch has been carried out using FT-IR, pulsed-EPR, elemental analysis, ^<127>I-MR and viscometer for considering the reforming mechanism of pitch by iodine. Viscosity of pit h increased by 100。C iodine-treatment and de-hydration reaction took place during the iodine treatment. ^<127>I-NMR analysis reveled that almost iodine existed in pitch in a form of molecule or ion. Iodine made charge-transfer complexes with condensed aromatic molecules having ca.14 number of six-member-rings ; which was analyzed using pulsed-EPR etc.Carbon yield increased and the size in microstructure of produced carbon decreased by iodine treatment. C/C composites could be produced without densification process, i.e. in autoclave, using pitches having low softening point. The composites maintained its shear strength after higher heat-treatment. Gas analysis during carbonization revealed that iodine played an important role on polymerization during the process.Above the all results conclude as follows ; (1) iodine makes charge-transfer complex with molecules in pitch at low temperature and proceed de-hydration of the pitch. (2) Viscosity of the pitch increases, which results in good formability. (3) The microstructure of the produced carbon decreases.