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

采用FT-IR、脉冲EPR、元素分析、核磁共振和粘度计等手段对碘处理后的沥青进行了精确的评价，以探讨碘对沥青的转化机理。PIT H的粘度提高了100。C碘处理和脱水反应发生在碘处理过程中。核磁共振分析表明，几乎碘以分子或离子的形式存在于沥青中。碘与稠合芳香族分子形成了约14个六元环的电荷转移络合物，并用脉冲电子顺磁共振等手段进行了分析，结果表明，碘处理后碳的产率增加，微观结构尺寸减小。使用软化点较低的沥青，可以在没有致密化过程的情况下，即在高压罐中生产C/C复合材料。复合材料经较高的热处理后仍保持其剪切强度。碳化过程中的气体分析表明，碘在聚合过程中起着重要的作用。结果表明：(1)碘在低温下与沥青中的分子形成电荷转移络合物，使沥青脱水。(2)沥青粘度增大，成型性好。(3)生成的碳的微观结构降低。

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.