Method for synthesizing polyaspartic acid by maleic anhydride and ammonia gas

A technology of polyaspartic acid and maleic anhydride, which is applied in the field of high molecular polymer preparation, can solve the problems of high viscosity of intermediates and low utilization rate of ammonia, and achieve the effects of low production cost and avoiding waste gas

Active Publication Date: 2015-06-24
HEBEI XIETONG ENVIRONMENTAL PROTECTION TECH CO LTD
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0008] The technical problem that the present invention needs to solve is to provide a kind of method that adopts maleic anhydride and ammonia to synthesize polyaspartic acid, to solve the intermediate viscosity that exist

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0030] 1) Put 97kg of maleic anhydride into the closed reactor connected with the tail gas absorption device, close the tail gas absorption device, start stirring, heat up to make it melt, and after the maleic anhydride is completely melted, slowly feed it into the reactor 17kg of ammonia gas, control the pressure in the reactor to 0.15Mpa~0.2Mpa, control the reaction temperature at 100°C to carry out the substitution reaction, stop the substitution reaction when the pressure in the reactor no longer drops, and open the tail gas absorption device to absorb the remaining gas; Adding 15kg mass fraction is 30% sodium hydroxide solution for neutralization reaction, controlling the reaction temperature to be 100°C, and after reacting for 0.5 hours, a mixture of sodium maleamate and ammonium maleamate is obtained;

[0031] 2) The temperature of the product in step 1) was directly raised to 200°C, and the polycondensation reaction was carried out under stirring. The polyco...

Embodiment 2

[0035] 1) Put 97kg of maleic anhydride into the closed reactor connected with the tail gas absorption device, close the tail gas absorption device, start stirring, heat up to make it melt, and after the maleic anhydride is completely melted, slowly feed it into the reactor 17kg of ammonia gas, control the pressure in the reactor to 0.15Mpa~0.2Mpa, control the reaction temperature at 100°C to carry out the substitution reaction, stop the substitution reaction when the pressure in the reactor no longer drops, and open the tail gas absorption device to absorb the remaining gas; Adding 33kg mass fraction is 30% sodium hydroxide solution to carry out neutralization reaction, control reaction temperature is 100 ℃, after reacting for 1 hour, obtain the mixture of sodium maleamate and ammonium maleamate;

[0036] 2) The temperature of the product in step 1) is directly raised to 220°C, and the polycondensation reaction is carried out under stirring. The polycondensation reaction t...

Embodiment 3

[0040] 1) Put 97kg of maleic anhydride into the closed reactor connected with the tail gas absorption device, close the tail gas absorption device, start stirring, heat up to make it melt, and after the maleic anhydride is completely melted, slowly feed it into the reactor 17kg of ammonia gas, control the pressure in the reactor to 0.15Mpa~0.2Mpa, control the reaction temperature at 100°C to carry out the substitution reaction, stop the substitution reaction when the pressure in the reactor no longer drops, and open the tail gas absorption device to absorb the remaining gas; Adding 48kg mass fraction is 30% sodium hydroxide solution to carry out neutralization reaction, control reaction temperature is 100 ℃, after reacting for 1 hour, obtain the mixture of sodium maleamate and ammonium maleamate;

[0041] 2) The temperature of the product in step 1) was directly raised to 240°C, and the polycondensation reaction was carried out under stirring. The polycondensation reaction time...

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PUM

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Abstract

The invention relates to a method for synthesizing polyaspartic acid by maleic anhydride and ammonia gas. The method comprises the following steps: performing substitution reaction of molten maleic anhydride and ammonia gas in a closed reactor and absorbing the residual gas after the completion of the substitution reaction; adding sodium hydrate solution into the reacted maleic anhydride and ammonia gas to perform neutrallzation reaction, so as to obtain a mixture of maleamic acid sodium and maleamic acid ammonium; directly heating the product in the closed reactor and performing condensation polymerization by stirring; steaming and drying the moisture after the completion of the condensation polymerization, so as to obtain the polysuccinimide solid; adding water in another reaction kettle and starting stirring; then adding the polysuccinimide solid into the reaction kettle and slowly adding sodium hydrate solution and heating to perform hydrolysis reaction, so as to obtain the polyaspartic acid solution. According to the method for synthesizing polyaspartic acid by maleic anhydride and ammonia gas, the production process is simplified and the polyaspartic acid prepared according to the method has a weight-average molecular weight of 2000-15000 and a molecular weight distribution index of 1.5-1.65, so that molecular weight requirements of various application domains are met and environment-friendly production process is realized.

Description

technical field [0001] The invention belongs to the field of high molecular polymer preparation, in particular to a method for synthesizing polyaspartic acid with different molecular weights by using maleic anhydride and ammonia. Background technique [0002] Polyaspartic acid (PASP) is a kind of amino acid with a linear polyamide structure and molecular chains of α and β types. Because the molecular chain contains peptide bonds, it is easily degraded into CO by microorganisms and bacteria. 2 and H 2 O, so it has good biocompatibility, and has properties such as scale inhibition, corrosion inhibition, chelation, adsorption, dispersion and moisture retention. The molecular chain structure of PASP is as follows: [0003] . [0004] The process of synthesizing PASP is mainly to prepare the intermediate polysuccinimide (PSI), then hydrolyze the PSI to generate the crude product PASP, and finally obtain PASP through separation and purification. According to the raw materials...

Claims

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Application Information

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IPC IPC(8): C08G73/10
Inventor 唐量
Owner HEBEI XIETONG ENVIRONMENTAL PROTECTION TECH CO LTD
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