Mesophase pitch and preparation method thereof

Abstract

The invention provides a method for preparing mesophase pitch from direct coal liquefaction residues. The method mainly comprises the following steps: 1, extracting the direct coal liquefaction residues by using an organic solvent I to obtain extracted pitch; 2, dissolving the extracted pitch by using a polar organic solvent II, and carrying out solvent recovery on the soluble part to obtain refined pitch; 3, carrying out thermal polycondensation on the obtained refined pitch at a high temperature to obtain a thermal polycondensation product; and 4, carrying out reduced pressure flash evaporation on the thermal polycondensation product to obtain the mesophase pitch. The invention also provides the mesophase pitch. The spinnable indexes of the mesophase pitch are characterized in that the softening point, the aromatic carbon rate and the quinoline insoluble substance content of the mesophase pitch are 250-280DEG C, not lower than 0.9 and 35-45% respectively.

Description

technical field [0001] The invention relates to a mesophase pitch and a preparation method thereof, more specifically, to a method for preparing mesophase pitch by using coal direct liquefaction residue as a raw material and the mesophase pitch obtained therefrom. Background technique [0002] Pitch-based carbon fibers have attracted widespread attention due to their wide source of raw materials, low production cost, high carbon yield, and high modulus, and their applications are becoming more and more extensive. Anisotropic high-quality mesophase pitch is the precursor for preparing high-performance carbon fibers; only general-purpose carbon fibers can be obtained without isotropic pitch in the mesophase stage. Therefore, the modulation of mesophase pitch [0003] It is a key link in the preparation process of high-performance pitch fibers. [0004] Mesophase pitch for spinning requires ideal molecular composition and structure to make it suitable for subsequent applicati...

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Problems solved by technology

[0011] In order to solve the problems faced in the above-mentioned prior art, the present invention provides a mesophase pitch prepared from direct coal liquefaction residue and a method for preparing mesophase pitch from direct coal liquefaction residue. The present invention prepares mesophase pitch from direct coal liquefaction residue The method of mesophase pitch, under the premise of neither catalytic hydrogenation treatment nor addition of catalyst, the obtained coal direct liquefaction residue pitch is directly subjected to thermal polycondensation to prepare mesophase pitch for spinning, thus avoiding hydrogenation treatment and addition of catalyst Some problems brought about, such as increased process complexity, increased operating costs, worsened risk, difficulty in catalyst removal and recovery, etc.

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