A kind of preparation method of triangular section polyacrylonitrile carbon fiber

Abstract

The invention belongs to the field of polyacrylonitrile carbon fibers, and in particular relates to a polyacrylonitrile carbon fiber preparation method. The method comprises following steps of: with dimethyl sulfoxide as a solvent, performing polymerization reaction on polymerized monomer acrylonitrile and itaconic acid in the solvent, removing the monomer, defoaming and filtering so as to obtain a spinning solution; designing a triangular hole spinneret plate, installing the triangular hole spinneret plate at an outlet of a metering pump, extruding the spinning solution out through the metering pump so as to pass through an air layer and then enter a coagulation bath for solidification forming, and stretching so as to obtain a triangular-cross-section polyacrylonitrile nascent fiber; washing, drafting with hot water, oiling, drying and densifying, drafting with saturated steam, forming with steam heat and drying the polyacrylonitrile nascent fiber so as to obtain a triangular-cross-section polyacrylonitrile precursor; and pre-oxidizing and carbonizing the polyacrylonitrile precursor so as to obtain the triangular-cross-section polyacrylonitrile carbon fiber. The prepared polyacrylonitrile carbon fiber has a regular cross sections shape, uniform size, smooth surface and a small amount of defects.

Description

technical field [0001] The invention belongs to the field of polyacrylonitrile carbon fiber, in particular to a preparation method of triangular section polyacrylonitrile carbon fiber. Background technique [0002] Polyacrylonitrile carbon fiber and its composite materials have a series of excellent properties such as high specific strength, high specific modulus, high temperature resistance, corrosion resistance, fatigue resistance, creep resistance, electrical conductivity, heat transfer and small thermal expansion coefficient, and are widely used For aerospace and civil industries. Special-shaped cross-section carbon fiber is a special member of the carbon fiber family. In addition to having a series of excellent properties of circular cross-section carbon fibers, some carbon fibers with special cross-section shapes also have very high dielectric loss and magnetic loss. Functional materials with dual effects of structural enhancement and radar stealth. This kind of spec...

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Problems solved by technology

[0004] The prior art discloses a method for preparing a trefoil-shaped PAN-based carbon fiber precursor. It can be known from the disclosed content that the cross-sectional size of the trefoil-shaped fiber is uneven, resulting in uneven thickness of the fiber. When the external force acts, the thinner part of the fiber is more likely to break, which has an impact on the strength and elongation at break of the product. At the same time, the drying time disclosed in the prior art is 1-3 hours, which takes more time. The productivity of the product is low, which cannot meet the needs of mass production. At the same time, in the prior art, only carbon fiber precursors are prepared, and corresponding carbon fibers are not prepared. It is difficult to know the actual production operations.

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