Method for preparing polyacrylonitrile-based carbon nanofiber precursor

Abstract

The invention relates to a method for preparing a polyacrylonitrile-based carbon nanofiber precursor, which comprises the following steps of: (1) mixing polyacrylonitrile and a solvent in a mass ratio of 1:(7-16), stirring at the temperature of between 50 and 100 DEG C until the polyacrylonitrile is completely dissolved, and performing dry-jet wet electrostatic spinning to obtain fibers; (2) adding the fibers into a coagulating bath, and winding the fibers at the linear speed of 1 to 300m / min to obtain 1 to 200 nanofiber bundles; and (3) stranding and twisting the nanofiber bundles to obtain yarns, drawing, washing, and drying by using a hot roller to obtain the carbon nanofiber precursor. By the method, strands with indefinite length can be obtained, have high fiber orientation degree which cannot be changed with the spinning process, and have high stability; and the prepared nanofiber precursor has high mechanical property when used for next-step carbonization, tension can be applied in the carbonization process and carbon nanofibers with high mechanical property can be obtained through carbonization, and the nanofiber precursor has a good application prospect.

Description

technical field [0001] The invention belongs to the field of preparation of nano-carbon fiber precursors, in particular to a preparation method of polyacrylonitrile-based nano-carbon fiber precursors. Background technique [0002] Carbon fiber is a large-scale high-performance fiber used in industry, sports and civil use. The quality of its precursor has a crucial impact on the performance of carbon fiber. At present, the most important carbon fiber product is obtained by carbonizing the raw silk obtained by conventional spinning methods such as polyacrylonitrile, phenolic resin, cellulose and pitch. [0003] With the upsurge of nanotechnology in recent years, carbon nanofibers have also received attention. The methods commonly used to prepare carbon nanofibers include vapor deposition and electrospinning. Although the vapor deposition method can produce carbon nanotubes and nano-carbon fibers on a certain scale, the obtained carbon fibers cannot be theoretically infinitel...

AI Technical Summary

Problems solved by technology

Although the vapor deposition method can produce carbon nanotubes and nano-carbon fibers on a certain scale, the obtained carbon fibers cannot be theoretically infinitely long, while electrospinning can obtain nano-carbon fibers by spinning different nano-carbon fiber precursors and then carbonizing them. Theoretically, infinitely long

[0004] However, electrospinning usually obtains a non-woven fabric structure of nanofibers. Since the fibers are extremely thin and have not been stretched orientated, the fiber film obtained is usually of poor strength, and electrospinning cannot obtain continuous fibers like conventional spinning. fiber, the strength of the fiber cannot be improved by the usual post-treatment process

These all limit the application of electrospinning products, especially in the fields that have certain requirements on mechanical properties

At present, there are also some methods to prepare highly oriented electrospun fibers, but some of these methods are too restrictive and not universal, and others can only obtain small-scale highly oriented fibers, which cannot be scaled up.

[0005] In the published literature on electrospun carbon nanofibers, due to the poor mechanical properties of the precursors and the inability to apply tension during the carbonization process, the electrospun carbon fibers have almost no strength.

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