A method for preparing polyacrylonitrile-based carbon fiber precursors by dry-wet method

Abstract

The invention particularly relates to a method of preparing polyacrylonitrile-based carbon raw fibers by a dry-wet method. Firstly, dimethyl sulfoxide is used as a solvent, a spinning dope of an acrylonitrile binary or ternary copolymer is prepared, and then oblique spinning, solidification, water washing and hot drawing, air drying, oiling and drying, steam drawing, and relaxation and setting areconducted to prepare the polyacrylonitrile-based carbon raw fibers. By adopting the method of preparing the polyacrylonitrile-based carbon raw fibers by the dry-wet method, a control method of a drysection is simplified, the uniformity of the fibers is improved, the problem of sticking is overcome, and the uniformity of oiling is improved by air-drying. The method of preparing the polyacrylonitrile-based carbon raw fibers by the dry-wet method has a simple process, easy process control and high production efficiency, and can be used for continuously preparing uniform and stable high-performance polyacrylonitrile-based carbon raw fibers. The general formula of the copolymer adopted by the method of preparing the polyacrylonitrile-based carbon raw fibers by the dry-wet method is shown as follows.

Description

technical field [0001] The invention belongs to the technical field of carbon fiber preparation, and in particular relates to a method for preparing polyacrylonitrile-based carbon fiber precursors by a dry-wet method. Background technique [0002] Polyacrylonitrile-based carbon fiber has a series of excellent properties such as high specific strength, high specific modulus, high temperature resistance, corrosion resistance, fatigue resistance, electrical conductivity, and heat transfer. Equipment and other military and civilian industries have a wide range of applications. [0003] The dry-wet spinning is characterized by high-speed spinning, improving equipment utilization efficiency and reducing costs, and the carbon fiber produced by dry-wet spinning has fewer surface defects, which is conducive to the preparation of high-performance carbon fibers, and is an important direction for the development of carbon fiber preparation technology. . [0004] The preparation of hig...

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Problems solved by technology

[0010] The above patented methods and the actual production process still have the following common problems: (1) After spinning, the filaments enter the coagulation bath vertically, and after being bundled by the steering roller, they turn and pull out of the coagulation bath

[0011] This makes the filaments at the edge of the spinneret and the filaments at the center inconsistent due to the inconsistency of the residence time of the convergence in the dry section, and the resulting raw filaments are not uniform; and the convergence speed is fast, and the filaments are not solidified enough during bundling, which is easy to cause The adhesion between monofilaments affects the performance of the final carbon fiber; (2) The atmosphere in the dry section is high, which makes it difficult to implement the process or easily disturbs the level of the coagulation bath, which is not conducive to the preparation of stable raw silk; (3) Washing heat The thread after being drawn enters the oil tank for oiling directly or after being rolled. The large amount of hot water entrained in the thread will cause the oil to be unstable, making the oiling of the thread uneven

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