Preparation method of polyvinylamine

A technology of polyvinylamine and polyacrylamide, which is applied in the field of preparation of polyvinylamine, can solve the problems of small molecular weight, waste, and low concentration of reactants, and achieve the effects of reducing surface tension, reducing waste liquid discharge, and improving quality indicators

Inactive Publication Date: 2012-08-22
HEFEI UNIV OF TECH
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0007] The first is that this method generally uses water or methanol as a solvent, and the polyacrylamide input has a small molecular weight and a mass fraction of about 5%, and the reactant concentration is low, resulting in low industrial production capacity.
The second is the intermediate product of isocyanate generated during the Hofmann reaction, which will condense with amino and amide groups to form acyl uric by-products, which will reduce the yield of polyvinylamine products and affect product quality.
Fourth, post-treatment after the Hofmann rearrangement reaction needs to consume a large amount of lye, which not only wastes but also increases the cost of wastewater treatment

Method used

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  • Preparation method of polyvinylamine
  • Preparation method of polyvinylamine

Examples

Experimental program
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Effect test

Embodiment 1

[0024] Add 26ml of 15% NaOH solution into a 250mL three-necked flask and cool to -5°C, then add 56mL of 12.6% NaClO solution, add 0.25g of non-ionic surface-active nonylphenol polyoxyethylene ether and stir. At -5°C, add 7.1 g of polyacrylamide with a molecular weight of 600,000 to 1,000,000 in small amounts in 5 times, and stir while adding. Continue stirring for 1.5 h after the material dissolves to obtain a chlorinated amide solution.

[0025] Prepare 300 mL of sodium hydroxide solution with a concentration of 40%, and slowly add the obtained chlorinated intermediate solution at 30 mL / min under stirring at -5°C, and continue stirring for 6 h after the addition is complete. After the reaction was completed, the liquid phase was put into 4 times the volume of methanol to precipitate a solid, which was rinsed with methanol for suction filtration, and the filter cake was dried. Alkali-containing reaction mother liquor is distilled to recover methanol, and then after concentrat...

Embodiment 2

[0028] Add 26ml of 15% NaOH solution into a 250mL three-necked flask and cool to -5°C, then add 56mL of 12.6% NaClO solution, add 0.3g of polyoxyethylene lauryl ether and stir. At -5°C, add 7.1 g of polyacrylamide with a molecular weight of 600,000 to 1,000,000 in batches, and stir while adding. After the material was dissolved, the stirring was continued for 1 h to obtain a chlorinated amide solution.

[0029] After analyzing the sodium hydroxide recovered in Example 1, add sodium hydroxide so that the concentration reaches 40%, and under stirring at -5°C, slowly add the obtained chlorinated intermediate reaction solution at 30mL / min, after adding The stirring reaction was continued for 6h. After the reaction was completed, the liquid phase was put into 4 times the volume of methanol to precipitate a solid, which was rinsed with methanol for suction filtration, and the filter cake was dried. The reaction mother liquor containing alkali and methanol is recovered and recycled. ...

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Abstract

The invention discloses a preparation method of polyvinylamine. In the method, degradation reactions including chlorination, a rearrangement reaction, separation and purification are undergone on polyacrylamide serving as a raw material. In the chlorination, a nonionic surfactant is added into a mixed solution of sodium hydroxide and sodium hypochlorite, polyacrylamide serving as the raw materialis added in batches at the temperature between 10 DEG C below zero and 0 DEG C for reacting for 1 hour by stirring, and the dosage of the surfactant is 3-5 percent by weight of the weight of the raw material. In the rearrangement reaction, chlorination mixed liquor is slowly added into a sodium hydroxide solution with the concentration of 20-50 percent by mass at the temperature between 10 DEG C below zero and 0 DEG C at the speed between 15 millimeters per minute and 35 millimeters per minute for reacting for 5-8 hours by stirring, and at least 5 times of excessive alkali liquor is used according to the mass of polyvinylamine serving as the raw material. By adopting the nonionic surfactant in the method, the surface tension of the solution is lowered, stretching of a main chain is promoted, an amido group is fully shown and is fully chlorinated in time, and hydrolysis is reduced. Meanwhile, an alkali-containing mother liquor can be recovered and reused.

Description

1. Technical field [0001] The invention relates to a preparation method of polyvinylamine. 2. Background technology [0002] Polyvinylamine (PVAm) is a chain-like, multi-amino water-soluble new polymer material. Because the side functional amino group is very active, PVAm can perform most of the characteristic reactions of amino groups, thereby obtaining many special new functions. PVAm and its derivatives are used as flocculants, water-retaining agents, sizing agents, and reinforcing agents in papermaking in industries such as textiles, medicine, petroleum extraction and processing, and construction. At present, the synthesis methods of polyvinylamine mainly include Hofmann degradation method, poly N-vinyl formylated polymer hydrolysis method, and polyvinyl chloride digestion method. [0003] Hofmann downgrading polyacrylamide is the main method reported at present to synthesize PVAm, that is, in sodium hypohalite and sodium hydroxide aqueous solution, polyacrylamide under...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): C08F120/56C08F8/00C08F8/20
Inventor 冯乙巳叶加久王除非
Owner HEFEI UNIV OF TECH
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