Method for preparing urea formaldehyde fiber through circulating acid-alkali process

An acid-alkali method and urea-formaldehyde technology, which is applied in the fields of fiber chemical characteristics, wet spinning, textiles and papermaking, etc., can solve the problems that there are no related reports on fiber application, and achieve simple curing and crosslinking, improve spinnability, The effect of mild reaction conditions

Active Publication Date: 2019-10-22
ZHONGYUAN ENGINEERING COLLEGE
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0005] As urea-formaldehyde plastics and wood adhesives, urea-formaldehyde resin is widely used in the manufacture of furniture, household appliances, mechanical parts, electrical accessories, various buttons and cover plates, etc. It has developed rapidly due to its low price and good flame retardancy. There is no relevant report on the application of fiber

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0024] The method for preparing urea-formaldehyde fiber by the circulating acid-base method of the present embodiment, the steps are as follows:

[0025] (1) Dissolve PVA in water to obtain 1wt% PVA aqueous solution, add urea and formaldehyde (molar ratio is 1:0.4), the mass ratio of PVA to urea is 1:0.2, then add sodium hydroxide aqueous solution, adjust the pH value to 7.5 , react at 45°C for 0.5h; then add hydrochloric acid to adjust the pH value to 4.0, add the second batch of formaldehyde (the molar ratio of urea to it is 1:0.4), and react at 40°C for 0.1h;

[0026] (2) Add calcium hydroxide aqueous solution again, adjust the pH value to 7.4, then add paraformaldehyde (the ratio of urea and paraformaldehyde added in step (1) is 1:0.2), and react at 35°C for 0.4h; Finally, add hydrochloric acid to adjust the pH value to 3, and react at 40°C for 1 hour to obtain a spinning solution;

[0027] (3) The resulting spinning solution is wet-spun, using saturated sodium sulfate aq...

Embodiment 2

[0030] A method for preparing urea-formaldehyde fiber by circulating acid-base method, its steps are as follows:

[0031] (1) Dissolve PEG in water to obtain 30wt% PEG aqueous solution, add urea and paraformaldehyde (molar ratio is 1:1.5), the mass ratio of PEG to urea is 1:10, then add potassium hydroxide aqueous solution to adjust the pH value To 10.5, react at 95°C for 8h; then add sulfuric acid to adjust the pH to 6.9, add the second batch of formaldehyde (the molar ratio of urea to it is 1:1.5), and react at 95°C for 7h;

[0032] (2) Add sodium hydroxide aqueous solution again to adjust the pH value to 10.5, then add formaldehyde (the ratio of urea and formaldehyde added in step (1) is 1:2), react at 95°C for 8 hours; finally add sulfuric acid to adjust the pH When the value reaches 6, react at 85°C for 5 hours to obtain a spinning solution;

[0033] (3) The resulting spinning solution is wet-spun, using saturated sodium sulfate aqueous solution with a weight content of ...

Embodiment 3

[0036] A method for preparing urea-formaldehyde fiber by circulating acid-base method, its steps are as follows:

[0037] (1) Dissolve polyvinyl formal in water to obtain 20wt% polyvinyl formal aqueous solution, add urea and glutaraldehyde (molar ratio is 1:1.1), the mass ratio of polyvinyl formal to urea is 1: 3. Then add triethanolamine, adjust the pH value to 8.5, and react at 90°C for 3h; then add phosphoric acid to adjust the pH value to 5, add the second batch of formaldehyde (the molar ratio of urea to it is 1:0.9), and react at 85°C for 2h;

[0038](2) Add potassium hydroxide aqueous solution again, adjust the pH value to 8.5, then add acetaldehyde (the ratio of urea and acetaldehyde added in step (1) is 1:0.5), react at 75°C for 4 hours; finally add phosphoric acid Adjust the pH value to 4, and react at 80°C for 5 hours to obtain a spinning solution;

[0039] (3) The resulting spinning solution was wet-spun, using saturated sodium sulfate aqueous solution with a weig...

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Abstract

The invention discloses a method for preparing urea formaldehyde fiber through a circulating acid-alkali process. The method includes: adding urea, aldehyde and alkaline catalyst into a high molecularwater solution for reaction, sequentially adding aldehyde and acidic catalyst, adding alkaline catalyst and remaining aldehyde compound, adjusting to be acidic, finishing reaction, and subjecting a solution to spinning and thermosetting to obtain the urea formaldehyde fiber. By reasonably designing reaction process, molecular weight and structural controllability are improved, and spinnability and stability of the spinning solution are improved; the fiber serving as three-dimensional crosslinked fiber has the advantages of being low in cost, flame-retardant, heat-insulating, free of melting drop and nontoxic in burning and has wide application prospect.

Description

technical field [0001] The invention belongs to the field of preparation of special fibers, and in particular relates to a method for obtaining functional urea-formaldehyde fibers by preparing a urea-formaldehyde spinning solution through a cyclic acid-base method, wet spinning and thermal curing. Background technique [0002] The three-dimensional cross-linked fiber has the characteristics of flame retardancy, heat insulation and high carbonization yield, and has potential application value in the fields of functional textiles, carbon fiber and activated carbon fiber. However, due to the different preparation methods and structural characteristics of cross-linked fibers and oriented fibers, the development of cross-linked fibers is extremely slow. The existing cross-linked fibers are only phenolic fibers and melamine fibers. [0003] Phenolic fiber is the first three-dimensional cross-linked organic fiber. In 1968, J. Economy first applied for a related patent [Economy J, ...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): D01F6/78D01D5/06C08G12/12
CPCC08G12/12D01D5/06D01F6/78
Inventor 焦明立杨凯刁泉张啸梅贾万顺殷玉娜席艳君
Owner ZHONGYUAN ENGINEERING COLLEGE
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