Yozo Korai

Isotropic Carbon and Graphite Fibers from Chemically Modified Coal-Tar Pitch

A precursor for a general purpose carbon fiber was prepared from coal tar pitch (CP) modified with 10 % p-benzoquinone (BQ) at 380 ‡C for 3 hours. Such a modification raised the softening of the pitch from 85 ‡C to 271 ‡C at a yield of 43 %. The modified pitch was spun smoothly at a rate of 480 m/min into a fiber of 20 Μm diameter. The fiber was stepwise stabilized at 236 ‡C (5 ‡C/min) and 312 ‡C (1 ‡C/min) for 3 hours at each temperature. Successively,carbonization and graphitization were performed at 1,000 ‡C and 2,400 ‡C, respectively, for one hour. Both the carbonized and graphitized fibers exhibited tensile strength of 570 MPa. The structural parameters of carbon and graphite fibers were their orientation values of 56.2 and 58.1 %, relatively low Lc(002) of 11.24 and 25 å, and large interlayer spacing (d002) of 3.86 and 3.49 å, respectively.

Molecular Alignment and Domain Assembles in the Uni-chromic Mesophase Spherules Prepared from Synthetic Naphthalene Isotropic Pitch

TitleMolecular Alignment and Domain Assembles in the Uni-chromicMesophase Spherules Prepared from Synthetic Naphthalene Isotropic PitchAuthor(s)Chang, Young-Chul; Sohn, Hun-Joon; Wang, Yong-Gang; Korai, Yozo;Nakagawa, Yoshiteru; Mochida, IsaoCitation九州大学大学院総合理工学研究科報告 ¦¦ 21(2) ¦¦ p161-165; Engineeringsciences reports, Kyushu University ¦¦ 21(2) ¦¦ p161-165Issue Date 1999-09URL http://hdl.handle.net/2324/16557Right