Urea formaldehyde preparation method adopting batch adding

A technology of adding urea-formaldehyde in stages, applied to the chemical characteristics of fibers, single-component synthetic polymer rayon, textiles and papermaking, etc., can solve the problems of fiber applications that have not been reported, and achieve simple curing and crosslinking, The effect of high limiting oxygen index and high flame retardant safety

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, wood adhesives, etc., urea-formaldehyde resin is widely used in the manufacture of furniture, household appliances, mechanical parts, electrical

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0024] The method for preparing urea-formaldehyde fiber by adding in stages 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 to obtain spinning solution;

[0027] (3) The resulting spinning solution is wet-spun, using saturated sodium sulfate aqueous solution with a weight content of 0.1% boric acid as a coagulation bath, and the winding speed is 10m / ...

Embodiment 2

[0030] The method for preparing urea-formaldehyde fiber by adding in stages of the present embodiment, the 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, adjust the pH value to 10.5, then add formaldehyde (the ratio of urea and formaldehyde in step (1) is 1:2), and react at 95°C for 8 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 5% boric acid as a coagulation bath, and the winding speed is 500m / min at a temperatu...

Embodiment 3

[0036] The method for preparing urea-formaldehyde fiber by adding in stages of the present embodiment, the 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), and react at 75°C for 4 hours to obtain a spinning solution ;

[0039] (3) The resulting spinning solution was wet-spun, using saturated sodium sulfate aqueous solution with a weight content of 3% boric acid as a coagulation bath, and the wind...

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Abstract

The invention discloses a urea formaldehyde preparation method adopting batch adding. The method includes: adding urea, aldehydes and an alkaline catalyst into a macromolecule aqueous solution to perform reaction, sequentially adding aldehydes, an acidic catalyst, an alkaline catalyst and the rest of aldehyde compounds, spinning with a wet spinning frame after the reaction, heating and curing theas-spun fibers subjected to coagulating bath winding in a drying oven, naturally cooling, and taking out to obtain the urea formaldehyde fibers. The method has the advantages that the spinnability andstability of the spinning solution are increased by reasonably designing the reaction process, and the fibers serving as three-dimensional crosslinked fibers are low in cost, flame-retardant, thermal-insulation, free of melting drops, nontoxic when being combusted, promising in application prospect and the like.

Description

technical field [0001] The invention belongs to the field of preparation of special fibers, and specifically relates to a method for obtaining functional urea-formaldehyde fibers by adding aldehyde compounds in stages, preparing urea-formaldehyde spinning solution, 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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IPC IPC(8): D01F6/76C08G12/12
CPCD01F6/76C08G12/12
Inventor 焦明立杨凯曹健曾灏宪张啸梅贾万顺刘英席艳君
Owner ZHONGYUAN ENGINEERING COLLEGE
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