Method for preparing high uniformity para-aramid

A para-aramid and polar solvent technology, which is applied in the field of preparation of high-uniformity para-aramid, can solve problems such as fiber damage, achieve narrow molecular weight distribution, reduce the possibility of defect points, and improve overall uniformity and the effect on the mechanical properties

Inactive Publication Date: 2019-07-19
DONGHUA UNIV +1
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

However, the existence of low molecular weight PPTA may form defect points inside during use, thereby causing damage to the overall fiber

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0030] (1) PPTA resin raw material powder (4.9dL / g, 800 mesh) is added the CaCl that mass fraction is 15% 2 -in NMP solution, stirring and blending at 80° C. for 1 h, filtering, washing with water, and drying at 100° C. to obtain PPTA resin powder.

[0031] (2) Blend the PPTA resin powder obtained in step (1) with 99.5% concentrated sulfuric acid, wherein the PPTA mass fraction is 18%, and the blend is mixed, dissolved and defoamed by a twin-screw at 80° C. to obtain a spinning stock solution.

[0032] (3) Extrude the spinning stock solution obtained in step (2) from the spinneret, pass through an air layer with a height of 10mm, enter a coagulation bath with a temperature of 5°C, wash with water, dry at 100°C, and heat-set at 200°C to obtain the Aramid.

[0033] Carry out fiber mechanical property test to many in a bunch of fiber, different sections, the result shows: the para-aramid fiber strength obtained in this embodiment is 20.12cN / dtex, and relative average deviation v...

Embodiment 2

[0035] (1) Add PPTA resin raw material powder (5.5dL / g, 1500 mesh) to CaCl with a mass fraction of 20% 2 -NMP solution, stirring and blending at 100°C for 2h, filtering, washing with water, and drying at 100°C to obtain PPTA resin powder.

[0036] (2) Blend the PPTA resin powder obtained in step (1) with 99.9% concentrated sulfuric acid, wherein the PPTA mass fraction is 19.5%, and the blend is mixed, dissolved and defoamed by a twin-screw at 90° C. to obtain a spinning stock solution.

[0037] (3) Extrude the spinning stock solution obtained in step (2) from the spinneret, pass through an air layer with a height of 5mm, enter a coagulation bath with a temperature of 2°C, wash with water, dry at 100°C, and heat-set at 220°C to obtain the Aramid.

[0038] The fiber mechanical performance test is carried out on multiple fibers and different sections in a bundle of fibers. The results show that the strength of the para-aramid fiber obtained in this embodiment is 21.72cN / dtex, an...

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Abstract

The invention relates to a method for preparing high uniformity para-aramid. The method comprises the steps of adding a polyparaphenylene terephthalamide PPTA resin raw material into a polar solvent system, pretreating, filtering, water-washing and drying, and obtaining PPTA resin powder; dissolving the PPTA resin powder in concentrated sulfuric acid to obtain a PPTA-H2SO4 spinning stock, extruding from a spinneret, through an air layer, entering a coagulation bath, and then washing, drying and heat-setting to obtain the para-aramid. The method pretreats the PPTA resin raw material powder, reduces the existence of the low molecular weight PPTA in the raw material, weakens the possibility that the low molecular weight PPTA becomes a defect in the finished fiber, improves the uniform performance of the PPTA fiber as a whole, and has important significance on the industrial production of a polyparaphenylene terephthalamide fiber.

Description

technical field [0001] The invention belongs to the field of preparation of para-aramid fibers, in particular to a preparation method of para-aramid fibers with high uniformity. Background technique [0002] Poly(p-phenylene terephthalamide) (PPTA) fiber has excellent thermal properties, chemical stability, electrical insulation, excellent wear resistance, etc., and is currently widely used in aerospace, national defense, transportation, communications, Sports and leisure, rope optical cable and other fields. Due to the intense synthesis process of PPTA, it is difficult to control the overall uniformity of the synthesis, and the terminal group of the monomer is easily deactivated to form a capping agent, resulting in the presence of low molecular weight PPTA in the raw material powder of high molecular weight PPTA resin. The existence of low molecular weight PPTA usually easily leads to defective points in the finished para-aramid fiber, which affects the overall performanc...

Claims

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Application Information

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IPC IPC(8): D01F6/60
CPCD01F6/605
Inventor 胡祖明曹煜彤于俊荣张浩赵开荣宋数宾王彦
Owner DONGHUA UNIV
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