Intermediate-phase pitch

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Intermediate-phase asphalt is an optically anisotropic spherical polymer with a diameter of 5 micrometers to 100 micrometers, formed when aromatic hydrocarbon compounds belonging to the asphalt category are heat-treated at 350°C in an inert atmosphere. Through a series of chemical reactions such as polycondensation, highly planar and thermodynamically stable condensed polycyclic aromatics are generated, which then arrange themselves in an orderly manner under the influence of surface tension. The so-called carbon intermediate phase refers to the intermediate liquid crystal state during the transition of asphaltic organic compounds into solid carbon materials; hence it is called a carbon intermediate phase or carbon liquid crystal. During further heat treatment, the microspheres gradually grow and merge to form an intermediate phase within the asphalt as a whole. They have been widely studied and used as raw materials for high-performance intermediate-phase asphalt-based carbon fibers, acicular coke, and advanced binders. Depending on the content of mesophase in the asphalt, various types of mesophase asphalt suitable for different applications can be obtained through treatment. An index for mesophase pitch: ash content < 350 ppm  ； Coking value: ≥90% ； Intermediate phase content: ≥95% ； Softening point: 260–280°C. Application areas: high-performance carbon/carbon composite materials, activated carbon microspheres with extremely high specific surface area, anode materials for lithium-ion batteries, catalyst carriers, carbon films, foam carbon, etc.; it has wide practical value in the aviation, aerospace, and industrial sectors.