Preparation method of polyacrylonitrile-based carbon fiber precursor

Abstract

The invention relates to a preparation method of a polyacrylonitrile-based carbon fiber precursor; after filament-out of a polyacrylonitrile spinning solution, the polyacrylonitrile spinning solution enters into a stage of non solidification bath, and then enters into a composite solidification molding process of a solidification bath. The preparation method specifically includes the following steps: after solidification molding of the polyacrylonitrile spinning solution by the composite solidification molding process, successive drafting, water washing, oiling, drying, steam drafting or boiling water drafting, heat setting, drying, and filament collection. The preparation method can overcome the shortcomings of a traditional wet and dry process and wet process, and is conducive to the control of raw filament cortex structure. By use of the process, a spinning speed more than 300m / min can be achieved, the obtained raw filament has a surface groove structure similar with that of a wet-method raw filament, is soft in hand feeling and good in splitting property, and the carbonized strength is higher than 5.8GPa. The preparation method belongs to the technical field of preparation methods of the polyacrylonitrile-based carbon fiber precursor.

Description

technical field [0001] The invention belongs to the technical field of preparation methods of polyacrylonitrile-based carbon fiber precursors, and in particular relates to a method for preparing high-performance carbon fiber precursors by using a non-coagulation bath and a coagulation bath combined coagulation molding process. Background technique [0002] At present, polyacrylonitrile (PAN)-based carbon fiber precursors mainly adopt two processes: wet process and dry-wet process. Because in the dry-wet process, the spinning dope flows out of the spinneret holes and passes through an air layer before entering the coagulation bath, the Burroughs effect of the dope trickle can be alleviated or even eliminated. In the wet process, the solidification process will occur from the surface to the inside when the fine stream of the stock solution flows out of the spinneret hole during the extrusion expansion stage. The higher the tension is, the more obvious it is, and the tension o...

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Problems solved by technology

[0005] Patent JP55-097199 proposes a method of changing the atmosphere in the dry section of the dry-wet process. The problem with this method is that the air flow will interfere with the fibers in the dry section. For spinning solutions with low viscosity, it will affect the stability of spinning nature, and also does not solve the problem of roaming

[0006] To sum up, the existing polyacrylonitrile-based carbon fiber precursor production process has the following disadvantages: 1. The spinning produced by the dry-wet method has a dense surface structure, which reduces the spinning performance; 2. The dry-wet process will occur Parallel phenomenon; 3. There is a problem of overflow in the dry-wet process that introduces the atmosphere in the dry section

4. The dry and wet process cannot form the groove surface like the raw silk of the wet process

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