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A method for removing hcl in the production process of para-aramid pulp

A para-aramid fiber pulp and production process technology, applied in the field of polymer synthesis, can solve the problems of low HCl removal efficiency, environmental pollution, and high price of acid binding agents, and achieves reduction of reinvestment costs, improvement of operating environment, The effect of promoting a positive reaction rate

Inactive Publication Date: 2015-08-12
BEIJING INSTITUTE OF TECHNOLOGYGY
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0008] The purpose of the present invention is to solve the problems of high price of acid-binding agent, serious environmental pollution, and low efficiency of removing HCl in the process of preparing para-aramid pulp by the existing low-temperature solution direct polycondensation method, and to provide a method for removing para-aramid pulp. Method of HCl in Aramid Pulp Production Process

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0024] Heat 100ml of NMP to 80°C; add 4.28g of CaCl activated at high temperature 2 , stir until completely dissolved; cool to room temperature, add 2.70g PPDA powder while stirring; after it is completely dissolved, add 2.80g powdered CaO, cool the reaction system to 0°C with an ice-salt bath, and add in two times TPC powder, after adding 2.54g of TPC powder for the first time, stir at a high speed at a stirring rate of 1000r / min; add the remaining 2.54g of TPC powder after 3 minutes; Add 14mg CaO and stir for 3min to obtain a light yellow PPTA slurry; the prepared PPTA slurry is diluted with 40ml NMP, and the slurry is sprayed into a coagulation solution composed of high-speed shear NMP (40ml) and water (10ml), and the stirring speed 3000r / min, cut for 10min to form chopped fiber-like pulp fibers, and after suction filtration, wash and dry to obtain PPTA pulp.

[0025] Dissolve 0.125g of completely dried para-aramid pulp sample in 25ml of concentrated sulfuric acid, and use...

Embodiment 2

[0027] Heat 100ml of NMP to 80°C; add 4.28g of CaCl activated at high temperature 2 , stir until completely dissolved; cool to room temperature, add 3.24g PPDA powder while stirring; after it is completely dissolved, add 3.36g powdered CaO, cool the reaction system to -5°C with an ice-salt bath, and divide it twice Add TPC powder, after adding 3.04g TPC powder for the first time, stir at a high speed at a stirring rate of 1500r / min; add the remaining 3.04g TPC powder after 2 minutes; 16.8mg CaO was added to the mixture, stirred for 3min to obtain a light yellow PPTA slurry; the prepared PPTA slurry was diluted with 60ml NMP, and the slurry was sprayed into a coagulation solution composed of high-speed shearing NMP (50ml) and water (10ml), The stirring speed is 2500r / min, shearing for 15min to form pulp fibers in the form of chopped fibers, and washing and drying after suction filtration to obtain PPTA pulp.

[0028] Dissolve 0.125g of completely dried para-aramid pulp sample ...

Embodiment 3

[0030] Heat 100ml of NMP to 70°C; add 5.40g of CaCl activated at high temperature 2 , stir until completely dissolved; cool to room temperature, add 4.33g PPDA powder while stirring; after it is completely dissolved, add 4.48g powdered CaO, cool the reaction system to -10°C with an ice-salt bath, and divide it twice Add TPC powder, after adding 4.06g TPC powder for the first time, stir at high speed, the stirring rate is 2000r / min; add the remaining 4.06g TPC powder after 4min; after reacting for 0.5h; Add 44.8mg CaO to the reaction system, stir for 5min to obtain a light yellow PPTA slurry; dilute the prepared PPTA slurry with 50ml NMP, and spray the slurry into a coagulation solution composed of high-speed shear NMP (60ml) and water (10ml) In the process, the stirring rate is 3000r / min, shearing for 20min to form chopped fiber-like pulp fibers, and washing and drying after suction filtration to obtain PPTA pulp.

[0031] Dissolve 0.125g of completely dried para-aramid pulp ...

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PUM

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Abstract

The invention discloses a method for removing HCl in a para-aramid fiber pulp production process, which belongs to the field of polymer synthesis. The method comprises the following steps: firstly, completely dissolving p-phenylenediamine powder in a solvent with calcium chloride, and further adding powder CaO, wherein the mole amount of CaO is two times of that of p-phenylenediamine; subsequently adding paraphthaloyl chloride at twice in the time interval of 2-5 minutes, and stirring at high speed to react for 0.5-3 hours; further adding the powder CaO into the reaction system, and stirring to react for 3-5 minutes so as to obtain faint yellow PPTA (Poly-p-Phenylene Terephthamide) pulp; finally diluting the prepared PPTA pulp, adding the PPTA pulp into a solidification liquid according to a volume ratio of (2:1)-(4:1), wherein the solidification liquid consists of N-methyl pyrrolidone and water; and shearing at high speed, performing suction filtration, and subsequently washing and drying so as to obtain the PPTA pulp. By adopting the method disclosed by the invention, a reaction byproduct HCl can be effectively removed, the molecular weight of the para-aramid fiber pulp is increased, and the corrosion of HCl on equipment and the pollution on the environment are reduced.

Description

technical field [0001] The invention relates to a method for removing HCl in the production process of para-aramid pulp, belonging to the field of polymer synthesis. Background technique [0002] Para-aramid (PPTA) pulp is polyparaphenylene terephthalamide pulp, also known as aramid 1414 pulp (PPTA-pulp) in my country. PPTA-pulp is a PPTA differentiated product developed in the past 20 years. PPTA pulp is rich in hairiness and has a needle-like tail; the surface is rough and has many branches and branches, and the specific surface area is large. Its emergence and rise is mainly as an ideal substitute fiber for asbestos and competes with glass fiber and carbon fiber in sealing materials, reinforcing materials and friction materials. In addition, the para-aramid paper prepared from PPTA pulp through the wet forming process of papermaking has light specific weight, high specific strength, high specific stiffness, impact resistance, outstanding corrosion resistance and self-ex...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): D01F6/90D01F1/10C08G69/32
Inventor 刘吉平刘珂嘉
Owner BEIJING INSTITUTE OF TECHNOLOGYGY