Mesophase pitch raw material used for preparing high-modulus high-thermal-conductivity carbon fiber, and preparation method thereof

Abstract

The invention relates to a mesophase pitch raw mateiral for preparing high-modulus high-thermal-conductivity carbon fiber, and a preparation method thereof. With a polarizing microscope measuring method, a mesophase content of the mesophase pitch raw material is 100%. With a capillary rheometer measuring method, a softening point of the mesophase pitch raw material is 220-260 DEG C. With an X-ray diffraction measuring method, an aromatic hydrocarbon macromolecule average sheet piling thickness Lc of the mesophase pitch raw material is larger than 8nm. According to the invention, a naphthalene series compound such as methylnaphthalene is adopted as a raw material; hydrogen fluoride-boron trifluoride is adopted as a catalyst; and through controlling a catalyst dose, polymerization conditions and low-boiling-point product separation conditions, the mesophase pitch is prepared. Compared with prior arts, the mesophase pitch provided by the invention has excellent spinnability, such that spinning process controlling and operation are facilitated. The mesophase pitch has good molecular orientation, such that high-modulus high-thermal-conductivity carbon fiber with high orientation degree can be prepared under a relatively low graphitization temperature. Therefore, the production cost of high-performance carbon fiber is greatly reduced.

Description

technical field [0001] The invention relates to the field of carbon industry, in particular to a mesophase pitch raw material required for the manufacture of high-modulus and high-thermal conductivity high-performance pitch-based carbon fibers and a preparation method. Background technique [0002] High-performance carbon fiber is light, has high strength and high elastic modulus, and plays a huge role as a high-value material in the fields of defense industry, aerospace, cutting-edge technology, pillar industry, and daily life. The demand for high-performance carbon fiber is increasing. The rate of greater than 10% has increased significantly year by year. [0003] According to the classification of raw materials used, carbon fiber can be divided into polyacrylonitrile-based (PAN) carbon fiber, pitch-based carbon fiber and viscose-based carbon fiber. At present, carbon fiber products are mainly the first two types, of which PAN-based carbon fiber accounts for about 70% and...

AI Technical Summary

Problems solved by technology

Solid catalysts such as aluminum trichloride and alumina are difficult to separate from the reaction system, so there is a disadvantage that the catalyst is difficult to recycle and reuse. This not only increases the cost of carbon fiber manufacturing, but the more fatal disadvantage is that even if only a small amount remains in the pitch fiber The catalyst will also lead to a serious decrease in fiber strength in the subsequent pre-oxidation, carbonization, and graphitization projects

However, this method cannot effectively improve the degree of orientation of mesophase pitch fibers, and the later graphitization treatment still needs to be operated above 3000 °C