Method for preparing aromatic polysulphonamide fibers

Abstract

The invention relates to a method for preparing aromatic polysulphonamide fibers. The method comprises the following steps of: extruding a solution of aromatic polysulfonamide with the apparent viscosity of 20-200Pa.s at the temperature of between 60 and 160DEG C by using spinneret orifices, and making the extruded silk pass through an air layer and enter a coagulating bath, wherein a ratio of a drawing rate for coagulating bath outlet to a spinneret orifice extrusion rate is 1.2-5; and performing at least two stages of plasticizing draw and wash draw, and performing dry draw and further high temperature hot draw to obtain aromatic polysulphonamide fibers with the filament number of 1.0-5.0dtex and the breaking strength of more than 3.8cN / dtex. In the method for preparing the aromatic polysulphonamide fibers, a dry jet wet spinning process is adopted, the height orientation of as-spun fibers is ensured through the forward draw of a spinning jet and the drawing process in the plasticizing, washing and drying stage by stage, macromolecular orientation and crystallization are improved by high temperature draw with lower draw multiple, and the strength of the fibers is improved.

Description

technical field [0001] The invention relates to a preparation method of polyaryl sulfone amide fibers. Background technique [0002] Polyarylene sulfone amide fiber is a kind of heat-resistant fiber mainly for industrial use and special protection. It is a kind of fiber that can be used for a long time above 250 ℃, or can be used instantly at a higher temperature. [0003] Polyaryl sulfone amide fiber has excellent heat resistance, good electrical insulation, good dimensional stability and chemical corrosion resistance, and can still maintain good physical properties when exposed to high temperatures. Fireproof clothing and F.H grade electrical insulating paper and some other industrial applications. [0004] The existing polyaryl sulfone amide fiber is prepared by using N,N-dimethylacetamide (DMAc) as a solvent wet spinning method. The steps are as follows: First, 4,4'-diaminodiphenylsulfone (4,4'-DDS), 3,3'-diaminodiphenylsulfone (3,3'-DDS) and the like in different prop...

AI Technical Summary

Problems solved by technology

[0008] For wet spinning, the viscosity of the solution is low, and the negative drawing of the spinneret is adopted, and the spinning solution is sprayed from the spinneret and directly enters the coagulation bath, and the outlet swells, which is not conducive to the orientation of the filaments in the coagulation bath. The formation of the structure makes it difficult for the as-spun silk to withstand a large stretch in the plasticizing stretching process, and there is almost no stretching in the process of washing and drying, and the plasticizing stretching of the as-spun silk cannot compensate for its orientation in the coagulation bath defect

The mechanical properties of the final fiber are not high, and the strength is lower than 3.2cN / dtex, so the application in occasions with high strength requirements is limited

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