Wet-spinning preparation method for polyacrylonitrile-based carbon fiber precursor

Abstract

The invention relates to a preparation method of a carbon fiber precursor, and in particular to a wet-spinning preparation method for a polyacrylonitrile-based carbon fiber precursor. The preparation method comprises the following steps: 1) metering a spinning solution of polyacrylonitrile-based carbon fiber by using a metering pump, ejecting from a 12000 spinning nozzle to form fine yarns, and feeding the yarns into a coagulating bath, wherein the coagulating bath is a dimethyl sulfoxide solution of which the temperature is 60-80 DEG C, the concentration is 30-50% and the pH value is 7.0-9.0; 2) performing wet-spinning at minus drafting of minus 80% to minus 25% and coagulating bath circulation volume of 1000-2000L/h, and performing water washing, water holding, oiling, drying, steaming drafting, thermal molding, and winding, thereby obtaining the polyacrylonitrile-based carbon fiber precursor, wherein the final spinning speed is up to 120-150m/min. According to the preparation method, in the wet-spinning process, curing molding conditions of wet-spinning are improved, and a high-temperature and low-concentration coagulating bath molding method is provided, so that surface defects of the polyacrylonitrile-based carbon fiber can be reduced, and the spinning speed of the wet-spinning method can be increased.

Description

technical field [0001] The invention relates to a method for preparing carbon fiber precursors, in particular to a method for preparing polyacrylonitrile-based carbon fiber precursors by wet spinning. Background technique [0002] In the preparation process of polyacrylonitrile-based carbon fiber precursors, coagulation molding is a key link in production, so the molding quality of primary fibers directly affects the comprehensive performance of precursors and carbon filaments. In wet spinning, coagulation forming mainly relies on double diffusion as the forming power, so that the spinning fine flow reaches a critical concentration, coagulation and precipitation to form nascent fibers. This molding method will generate surface grooves. The presence of appropriate surface grooves can improve the fiber splitting between fiber filaments and increase the specific surface area of ​​fibers, which is beneficial to improve the shear strength of composite materials. If the groove is...

AI Technical Summary

Problems solved by technology

[0003] The present invention mainly overcomes the need to improve the coagulation and forming conditions of wet spinning in the wet spinning process, and provides a wet spinning method for reducing surface defects of polyacrylonitrile-based carbon fibers through a high-temperature, low-concentration coagulation bath forming method. Silk method, mainly by controlling higher coagulation bath concentration and lower coagulation bath temperature to improve the groove depth and straightness of the surface of polyacrylonitrile-based carbon fiber during coagulation molding, thereby improving the performance of carbon fiber