阅读说明：本技术 一种谷氨酰胺接枝改性聚环氧琥珀酸及其制备方法和应用 (Glutamine graft modified polyepoxysuccinic acid and preparation method and application thereof ) 是由 杨玉华 刘皓伟 刘潘勤 尹召龙 杨志涛 张庚 李一正 苗长瑞 马全兴 袁倍倍 黄 于 2020-07-30 设计创作，主要内容包括：本发明公开了一种谷氨酰胺接枝改性聚环氧琥珀酸,该谷氨酰胺接枝改性聚环氧琥珀酸是通过谷氨酰胺与聚环氧琥珀酸发生接枝反应得到。与现有Lcys-PESA相比,在同等浓度下(10mg/L),本发明的谷氨酰胺接枝改性聚环氧琥珀酸对碳酸钙的阻垢率达100％,可降低水处理的成本。(The invention discloses glutamine grafting modified polyepoxysuccinic acid which is obtained by the grafting reaction of glutamine and polyepoxysuccinic acid. Compared with the existing Lcys-PESA, under the same concentration (10mg/L), the scale inhibition rate of the glutamine grafted modified poly-epoxy succinic acid of the invention to calcium carbonate reaches 100 percent, and the cost of water treatment can be reduced.)

1. The glutamine grafting modified polyepoxysuccinic acid is characterized in that: the glutamine grafting modified polyepoxy succinic acid is obtained by the grafting reaction of glutamine and polyepoxy succinic acid;

preferably, the molar ratio of the polyepoxysuccinic acid to the glutamine is 1: 0.6-1.0.

2. The glutamine graft-modified polyepoxysuccinic acid according to claim 1, characterized in that: the number average molecular weight of the glutamine grafting modified polyepoxysuccinic acid is not less than 3000, and preferably the number average molecular weight is 3500-3000.

3. The glutamine graft-modified polyepoxysuccinic acid according to claim 1 or 2, characterized in that: the ratio of the weight average molecular weight to the number average molecular weight of the glutamine grafting modified polyepoxysuccinic acid is 1.0-1.5, and more preferably 1.2.

4. The method for synthesizing the glutamine grafted modified polyepoxysuccinic acid according to any one of claims 1 to 3, comprising: mixing glutamine and polyepoxysuccinic acid, and heating and reacting under an acidic condition to obtain the glutamine grafted modified polyepoxysuccinic acid.

5. The method of synthesis according to claim 4, characterized in that: the molar ratio of the polyepoxysuccinic acid to the glutamine is 1: 0.6-1.0, and preferably the molar ratio of the polyepoxysuccinic acid to the glutamine is 1: 0.625.

6. The method of synthesis according to claim 5, characterized in that: the reaction temperature is 90-100 ℃, the reaction time is 1.5-2.5 hours, and the pH value is 5.1-5.5.

7. The synthesis method according to claim 4 or 5, characterized in that: the polyepoxysuccinic acid is prepared by the method comprising the following steps:

(1) dissolving maleic anhydride and sodium hydroxide in water, and heating for hydrolysis reaction;

(2) after the hydrolysis reaction is finished, adding sodium tungstate and hydrogen peroxide, and heating for epoxidation reaction;

(3) after the epoxidation reaction is finished, adding calcium hydroxide, and heating for polymerization reaction;

(4) washing a product obtained by the polymerization reaction with acidified methanol to obtain polyepoxysuccinic acid;

preferably, in the step (1), the molar ratio of the maleic anhydride to the sodium hydroxide is 1: 1.50-2.20, the temperature of the hydrolysis reaction is 50-55 ℃, and the time is 0.25-0.5 h;

preferably, in the step (2), the molar ratio of the maleic anhydride to the sodium tungstate to the hydrogen peroxide is 1: 0.018-0.025: 0.99-1.20, the reaction temperature is 65-70 ℃, the reaction time is 1.5-2.0 h, and the pH value is 6.0-7.0;

preferably, in the step (3), the molar ratio of the maleic anhydride to the calcium hydroxide is 1: 0.20-0.22, the reaction temperature is 85-90 ℃, the reaction time is 2.5-3.0 h, and the pH value is 12.0-13.0;

preferably, the pH value of the acidified methanol is 2.0-3.0.

8. The use of the glutamine grafted modified polyepoxysuccinic acid according to any one of claims 1 to 3 for scale inhibition and/or corrosion inhibition in water treatment; preferably, during water treatment, the glutamine grafting modified polyepoxysuccinic acid is added into the water sample to be treated according to the concentration of 5-10 mg/L.

9. A scale inhibitor for water treatment, characterized in that: the scale inhibitor contains the glutamine graft-modified polyepoxysuccinic acid according to any one of claims 1 to 3.

10. A scale and corrosion inhibitor for water treatment is characterized in that: the scale and corrosion inhibitor comprises the glutamine grafted modified polyepoxysuccinic acid, hydroxyethylidene diphosphonic acid, sodium molybdate and zinc salt according to any one of claims 1 to 3, and the components in percentage by weight are as follows: 14-15% of glutamine grafted modified polyepoxysuccinic acid, 27-38% of sodium molybdate, 7-13% of hydroxyethylidene diphosphonic acid and zinc salt for supplementing to 100%;

preferably, the components are as follows by weight percent: 14.6 percent of glutamine graft modified polyepoxysuccinic acid, 31.7 percent of sodium molybdate, 7.3 percent of hydroxyethylidene diphosphonic acid and zinc salt for supplementing to 100 percent;

preferably, the zinc salt is zinc sulfate or zinc chloride.

Technical Field

The invention belongs to the field of water treatment additives, and particularly relates to a glutamine grafting modified polyepoxysuccinic acid for water treatment and a preparation method thereof.

Background

Polyepoxysuccinic acid (PESA) is a green water treatment agent which is developed by Betz laboratories in the beginning of the 90 s of the 20 th century, has no nitrogen and phosphorus, has double effects of scale inhibition and corrosion inhibition and has good biodegradability. However, when the concentration of calcium and magnesium ions is higher, the scale inhibition rate of single use of PESA is lower than that of a phosphorus-containing scale inhibitor, the cost of a water treatment medicament is increased when the use concentration is increased, and the scale inhibition rate is only limited when the concentration is continuously increased after a certain threshold value is reached. In order to improve the scale inhibition efficiency of polyepoxysuccinic acid, the prior art approaches generally compound or modify the polyepoxysuccinic acid with other medicaments.

Chinese patent CN102993431A discloses a preparation and application method of polyepoxysuccinic acid derivative scale inhibitor. In particular discloses L-cysteine modified polyepoxysuccinic acid (Lcys-PESA), the scale inhibition rate of calcium carbonate under the concentration of 10mg/L reaches 94.2%, but the scale inhibition performance is still to be improved.

Disclosure of Invention

The invention aims to solve the problem of low scale inhibition rate of the existing polyepoxysuccinic acid and provides the glutamine grafting modified polyepoxysuccinic acid with higher scale inhibition rate.

In order to achieve the purpose, the technical scheme adopted by the invention is as follows:

the glutamine grafting modified polyepoxysuccinic acid is obtained through the grafting reaction of glutamine and polyepoxysuccinic acid.

Preferably, the molar ratio of polyepoxysuccinic acid to glutamine is 1:0.6 to 1.0, such as 1:0.6, 1:0.7, 1:0.8, 1:0.9, 1:1.0, 1:0.6 to 0.7, 1:0.7 to 0.8, 1:0.8 to 0.9, 1:0.9 to 1.0, 1:0.6 to 0.9, 1:0.6 to 0.8, most preferably 1: 0.625.

The glutamine is grafted to the polyepoxysuccinic acid by the condensation of the amino group on the glutamine and the carboxyl group on the polyepoxysuccinic acid.

Preferably, the number average molecular weight of the glutamine grafting modified polyepoxysuccinic acid is more than or equal to 3000, and more preferably, the number average molecular weight is 3500-3000.

Preferably, the ratio of the weight average molecular weight to the number average molecular weight of the glutamine grafting modified polyepoxy succinic acid is 1.0-1.5, and more preferably 1.2.

The synthesis method of the glutamine grafting modified polyepoxysuccinic acid comprises the following steps: mixing glutamine and polyepoxysuccinic acid, and heating and reacting under an acidic condition to obtain the glutamine grafted modified polyepoxysuccinic acid.

Preferably, the molar ratio of the polyepoxysuccinic acid to the glutamine is 1: 0.6-1.0.

Preferably, the reaction temperature is 90-100 ℃, the reaction time is 1.5-2.5 hours, and the pH value is 5.1-5.5.

Preferably, the polyepoxysuccinic acid is prepared by a method comprising the following steps:

(1) dissolving maleic anhydride and sodium hydroxide in water, and heating for hydrolysis reaction;

(2) after the hydrolysis reaction is finished, adding sodium tungstate and hydrogen peroxide, and heating for epoxidation reaction;

(3) after the epoxidation reaction is finished, adding calcium hydroxide, and heating for polymerization reaction;

(4) and washing a product obtained by the polymerization reaction with acidified methanol to obtain polyepoxysuccinic acid.

Preferably, in the step (1), the molar ratio of the maleic anhydride to the sodium hydroxide is 1: 1.50-2.20, the temperature of the hydrolysis reaction is 50-55 ℃, and the time is 0.25-0.5 h.

Preferably, in the step (2), the molar ratio of the maleic anhydride to the sodium tungstate and the hydrogen peroxide is 1: 0.018-0.025: 0.99-1.20, the reaction temperature is 65-70 ℃, the reaction time is 1.5-2.0 h, and the pH value is 6.0-7.0.

Preferably, in the step (3), the molar ratio of the maleic anhydride to the calcium hydroxide is 1: 0.20-0.22, the reaction temperature is 85-90 ℃, the reaction time is 2.5-3.0 h, and the pH value is 12.0-13.0.

Preferably, the pH value of the acidified methanol is 2.0-3.0.

The scale and corrosion inhibitor for water treatment comprises the glutamine grafted modified polyepoxysuccinic acid, hydroxyethylidene diphosphonic acid, sodium molybdate and zinc salt, and the components in percentage by weight are as follows: 14-15% of glutamine grafted modified polyepoxysuccinic acid, 27-38% of sodium molybdate, 7-13% of hydroxyethylidene diphosphonic acid and zinc salt for supplementing to 100%.

Preferably, the components are as follows by weight percent: 14.6 percent of glutamine graft modified polyepoxy succinic acid, 31.7 percent of sodium molybdate, 7.3 percent of hydroxyethylidene diphosphonic acid and zinc salt for supplementing to 100 percent.

Preferably, the zinc salt is zinc sulfate or zinc chloride.

The scale inhibition and corrosion inhibitor adopting the formula has the scale inhibition rate of 100% on calcium carbonate, the corrosion rate of 0.004122-0.0230 mm/a on A3 carbon steel and the corrosion inhibition rate of 96.7-98.8%.

When water is treated, the glutamine grafting modified polyepoxysuccinic acid is added into the water sample to be treated according to the concentration of 5-10mg/L, specifically 5, 6, 7, 8, 9 or 10 mg/L.

The water treatment means that a certain amount of medicament is added into water running in equipment or a pipeline so as to prevent or reduce the precipitation and the scaling of insoluble salt in the water on the surface of the equipment or the pipeline and reduce the corrosion to the equipment or the pipeline.

Compared with the existing Lcys-PESA, under the same concentration (10mg/L), the scale inhibition rate of the glutamine grafted modified polyepoxysuccinic acid to calcium carbonate reaches 100 percent.

Drawings

FIG. 1 is a nuclear magnetic hydrogen spectrum of polyepoxysuccinic acid;

FIG. 2 is a nuclear magnetic hydrogen spectrum of glutamine grafted modified polyepoxysuccinic acid (GIN-PESA);

FIG. 3 is an infrared spectrum of polyepoxysuccinic acid and glutamine graft-modified polyepoxysuccinic acid;

FIG. 4 is a GPC test curve of polyepoxysuccinic acid and glutamine graft-modified polyepoxysuccinic acid;

FIG. 5 is an infrared spectrum of a scale sample to which GIN-PESA was added and a scale sample of a blank test;

FIG. 6 is an XRD spectrum of a blank test scale sample;

FIG. 7 is an XRD spectrum of a soil sample with GIN-PESA added;

FIG. 8 is an SEM image of a blank test (a) scale sample and a scale sample to which GIN-PESA (b) is added;

FIG. 9 is SEM images of surfaces of fresh A3 carbon steel coupons (a), blank (b), with GIN-PESA (c) added, and A3 carbon steel coupons with formulation (d) added after cleaning at 5000 times;

FIG. 10 is an EDS chart showing the specimens of GIN-PESA compound drug before surface washing.

Detailed Description

The technical solution of the present invention will be described in further detail with reference to the following embodiments and accompanying drawings.