阅读说明：本技术 一种环氧琥珀酸-2-（羟基亚氨基）丙二酸钠共聚物的制备方法 (Preparation method of epoxysuccinic acid-2- (hydroxyimino) sodium malonate copolymer ) 是由 程终发 周响 于 2020-12-23 设计创作，主要内容包括：本发明公开了一种环氧琥珀酸-2-(羟基亚氨基)丙二酸钠共聚物的制备方法,属于精细化学品技术领域,以环氧琥珀酸和2-(羟基亚氨基)丙二酸二甲酯为单体,采用阴离子聚合生成共聚物,不含硫磷,具有生物降解性,绿色环保；环氧琥珀酸-2-(羟基亚氨基)丙二酸钠共聚物增加了单位质量中羧基含量,且引入羟基,不但提高吸附中心的单位含量,在不同基团的协同作用下,有效提高其阻垢缓蚀性能。(The invention discloses a preparation method of an epoxysuccinic acid-2- (hydroxyimino) sodium malonate copolymer, belonging to the technical field of fine chemicals, wherein epoxysuccinic acid and 2- (hydroxyimino) dimethyl malonate are used as monomers, and anion polymerization is adopted to generate the copolymer, so that the copolymer does not contain sulfur and phosphorus, has biodegradability and is green and environment-friendly; the epoxy succinic acid-2- (hydroxyimino) sodium malonate copolymer increases the carboxyl content in unit mass, and the hydroxyl is introduced, so that the unit content of an adsorption center is increased, and the scale and corrosion inhibition performance of the copolymer is effectively improved under the synergistic effect of different groups.)

1. A preparation method of an epoxysuccinic acid-2- (hydroxyimino) sodium malonate copolymer is characterized by comprising the following steps:

1) uniformly mixing 2- (hydroxyimino) malonic acid dimethyl ester, epoxy succinic acid and sodium hydroxide to obtain a monomer mixture;

2) adding ethylene glycol, potassium hydroxide and crown ether into a reaction kettle, heating to 110-120 ℃, stirring for 1h, and cooling to 70-80 ℃;

3) heating the reaction kettle to 100-110 ℃, starting stirring, adding the monomer mixture, keeping the temperature for 7-9 hours after the monomer mixture is added for 3-4 hours to obtain an epoxysuccinic acid-2- (hydroxyimino) malonic acid dimethyl ester copolymer, and hydrolyzing to obtain the epoxysuccinic acid-2- (hydroxyimino) sodium malonate copolymer.

2. The method according to claim 1, wherein the molar ratio of the dimethyl 2- (hydroxyimino) malonate to the epoxy succinic acid to the sodium hydroxide is 0.1-0.5: 1: 1 to 2.

3. The method according to claim 1, wherein the molar ratio of the ethylene glycol to the epoxy succinic acid is 3-5: 1.

4. the method according to claim 1, wherein the amount of the potassium hydroxide is 3-5% of the mass of the epoxy succinic acid; the crown ether is 18-crown-6; the molar ratio of the used amount of the crown ether to the potassium hydroxide is 1-1.2: 1.

5. the method as claimed in claim 1, wherein after the temperature reduction in the step (2), the water is pumped in vacuum for 1 hour, and the air in the system is replaced by nitrogen.

6. The method of claim 5, wherein the vacuum is at a pressure of-0.1 to-0.08 MPa.

7. The method according to claim 1, wherein the hydrolysis comprises the specific steps of hydrolyzing the epoxysuccinic acid-2- (hydroxyimino) malonic acid dimethyl ester copolymer, dropwise adding sodium hydroxide to adjust the pH of the system to 10-12, filtering after hydrolysis, externally distilling out ethylene glycol, methanol and water in vacuum, and diluting the residual polymer with water to obtain an epoxysuccinic acid-2- (hydroxyimino) malonic acid sodium copolymer solution with the mass fraction of 40%.

8. The method as claimed in claim 7, wherein the pressure of the vacuum external steaming is-0.1 to-0.095 MPa.

9. The method according to claim 1, wherein the monomer mixture in step (3) is fed in batch mode by a solid feeding device, the batch time is 5min, and the feeding amount and the feeding batch of each batch are determined by the total amount of the monomer mixture and the feeding time.

Technical Field

The invention relates to the technical field of fine chemicals, in particular to a preparation method of an epoxysuccinic acid-2- (hydroxyimino) sodium malonate copolymer.

Background

Polyepoxysuccinic acid is one kind of green water treating agent with the functions of both corrosion inhibiting and scale inhibiting, and owing to the characteristics of its non-phosphorus and non-nitrogen structure, it will not eutrophicate water body and can be degraded by microbes in nature.

The polyepoxysuccinic acid as scale inhibitor will not lose effectiveness under the conditions of high hardness, high alkalinity and high pH value due to the formation of scale inhibitor-calcium compound. When the polyepoxysuccinic acid is used as a scale inhibitor in water treatment, the amount of acid added in the process of adjusting the pH value can be reduced, and the polyepoxysuccinic acid can be used in a system with limited use of phosphate and is widely applied to various fields of industrial water treatment.

Due to the single polyepoxysuccinic acid functional group, the performance is single, and the inhibition capability on calcium phosphate scale and zinc scale and the performance on the stability of metal ions are not outstanding. Researches show that the polymer mainly has functional groups such as carboxylic acid group, amino group, sulfonic group, hydroxyl group and the like which play a role in scale inhibition and dispersion. Therefore, in the process of synthesizing the polymer, a functional group is introduced by a copolymerization or grafting method, so that the method becomes an effective way for improving the scale inhibition dispersion performance of the polymer. For example, in patent CN1557805A, maleic anhydride is hydrolyzed and then epoxidized, and then ionic polymerization is carried out in the presence of diethylenetriamine to generate amino polyepoxysuccinic acid. The polymer has good scale inhibition and dispersion capacity on various scales of systems such as circulating cooling water, boiler water, oil field water, seawater desalination and the like. Patent CN1319876C provides a preparation method of biodegradable water treatment agent polyepoxysulfocarboxylic acid, and the polyepoxysulfocarboxylic acid or salt prepared by the method has good scale inhibition and dispersion properties, and can be widely used for scale inhibition and corrosion inhibition treatment of industrial water.

Disclosure of Invention

Aiming at the problems of single polyepoxysuccinic acid functional group and single performance in the prior art, the invention provides a preparation method of an epoxysuccinic acid-2- (hydroxyimino) sodium malonate copolymer.

A method for preparing epoxy succinic acid-2- (hydroxyimino) sodium malonate copolymer takes epoxy succinic acid and 2- (hydroxyimino) malonic acid dimethyl ester as monomers, and anion polymerization is carried out to generate copolymer, which mainly comprises the following steps:

the method comprises the following steps: uniformly mixing 2- (hydroxyimino) malonic acid dimethyl ester, epoxy succinic acid and sodium hydroxide according to a certain proportion to obtain a monomer mixture;

step two: adding a certain amount of glycol, potassium hydroxide and crown ether into a reaction kettle, heating to 110-120 ℃, stirring for 1h, cooling to 70-80 ℃, pumping water in vacuum for 1h, and replacing air in the system with nitrogen;

step three: heating the reaction kettle to 100-110 ℃, starting stirring, adding a monomer mixture according to a certain flow, continuously preserving the temperature for 7-9 h after the monomer mixture is added for 3-4 h, hydrolyzing, dropwise adding sodium hydroxide with the mass fraction of 20% in the hydrolysis process to adjust the pH of the system to 10-12, filtering after hydrolysis, externally evaporating glycol, methanol, crown ether and water in vacuum, and diluting the residual polymer with water to obtain the epoxy succinic acid-2- (hydroxyimino) sodium malonate copolymer solution with the mass fraction of 40%.

Wherein the molar ratio of the dimethyl 2- (hydroxyimino) malonate, the epoxy succinic acid and the sodium hydroxide in the step 1 is (0.1-0.5) to 1: (1-2), preferably (0.1-0.2) 1: (1-1.5).

Wherein the molar ratio of the initiator ethylene glycol to the epoxy succinic acid in the step 2 is (3-5): 1, the using amount of the catalyst potassium hydroxide is 3-5% of the mass of the epoxy succinic acid, the complexing agent crown ether is 18-crown-6, and the molar ratio of the using amount to the catalyst potassium hydroxide is (1-1.2): 1.

wherein the pressure of the vacuum in the step 2 is-0.1 to-0.08 MPa, and the pressure of the vacuum in the step 3 is-0.1 to-0.095 MPa.

Wherein, the monomer mixture in the step 3 is added in batches and intermittently by using a solid feeding device, the intermittent time is 5min, and the adding amount and the adding batch of each batch are determined by the total amount of the monomer mixture and the adding time.

The invention has the beneficial effects that:

the invention takes ethylene glycol as an initiator, crown ether as a complexing agent and potassium ions as an initiator, and the anion copolymerizes epoxy succinic acid and 2- (hydroxyimino) malonic acid dimethyl ester. OH group^-Proton interference is shielded. The final product does not contain sulfur and phosphorus, has biodegradability and is green and environment-friendly; the epoxy succinic acid-2- (hydroxyimino) sodium malonate copolymer increases the carboxyl content in unit mass, and the hydroxyl is introduced, so that the unit content of an adsorption center is increased, and the scale and corrosion inhibition performance of the copolymer is effectively improved under the synergistic effect of different groups.

Detailed Description

The present invention is described in detail below by way of examples, which are intended to be illustrative only and not to be construed as limiting the scope of the invention, and one skilled in the art will be able to make variations within the scope of the invention based on the disclosure herein, in reagents, catalysts and reaction process conditions. All equivalent changes or modifications made according to the spirit of the present invention should be covered within the protection scope of the present invention.

Part of raw material specifications are as follows:

the purity of the epoxy succinic acid is 98.5 percent; the purity of the 2- (hydroxyimino) malonic acid dimethyl ester is 99 percent;

potassium hydroxide technical grade; sodium hydroxide technical grade;

the purity of the ethylene glycol is 98 percent.

Example 1

The method comprises the following steps: 16g of 2- (hydroxyimino) malonic acid dimethyl ester, 132g of epoxysuccinic acid and 40g of sodium hydroxide were mixed uniformly to give a monomer mixture, which was transferred to a solid feed apparatus in which air had been replaced with nitrogen.

Step two: adding 186g of ethylene glycol and 4g of potassium hydroxide into a reaction kettle, stirring and heating to 112 +/-2 ℃, preserving heat for 1h, cooling to 75 +/-5 ℃, externally steaming water at-0.1 MPa for 1.2h, closing the negative pressure, adding 19g of 18-crown-6, and replacing the air in the system with nitrogen for 20 min.

Step three: starting stirring, continuously heating the inside of the reaction kettle to 102 +/-2 ℃, adding a monomer mixture in a manner of 5g per batch at intervals of 5min, after 3.1h, continuously keeping the temperature for 7h, adding 50g of water, dropwise adding sodium hydroxide with the mass fraction of 20% for hydrolysis, adjusting the pH of the system to 10-12 through the dropping rate of the sodium hydroxide, filtering after 2h of hydrolysis, externally evaporating glycol, methanol, crown ether and water from the filtrate under-0.01 MPa, and diluting the residual polymer with water to obtain 418g of epoxy succinic acid-2- (hydroxyimino) sodium malonate copolymer aqueous solution with the mass fraction of 40.18%, which is recorded as R1.

Detecting the residual quantity of the monomer: 0.5 percent of 2- (hydroxyimino) malonic acid dimethyl ester, and no epoxy succinic acid residue.

Example 2

The method comprises the following steps: 32g of 2- (hydroxyimino) malonic acid dimethyl ester, 132g of epoxysuccinic acid and 60g of sodium hydroxide were mixed uniformly to give a monomer mixture, which was transferred to a solid feed apparatus in which air had been replaced with nitrogen.

Step two: adding 310g of ethylene glycol and 6.6g of potassium hydroxide into a reaction kettle, stirring and heating to 118 +/-2 ℃, preserving heat for 1h, cooling to 75 +/-5 ℃, externally steaming water at-0.08 MPa for 1.2h, closing the negative pressure, adding 31g of 18-crown-6, and replacing the air in the system with nitrogen for 20 min.

Step three: starting stirring, continuously heating the inside of the reaction kettle to 108 +/-2 ℃, adding a monomer mixture in a manner of 5g per batch at intervals of 5min, after 3.7h, continuously keeping the temperature for 9h, adding 50g of water, dropwise adding sodium hydroxide with the mass fraction of 20% for hydrolysis, adjusting the pH of the system to 10-12 through the dropwise adding rate of the sodium hydroxide, filtering after 2h of hydrolysis, evaporating ethylene glycol, methanol and water from the filtrate under the vacuum degree of-0.095 MPa, and diluting the residual polymer with water to obtain 476g of epoxy succinic acid-2- (hydroxyimino) sodium malonate copolymer aqueous solution with the mass fraction of 40.10%, which is marked as R2.

Detecting the residual quantity of the monomer: 0.4 percent of 2- (hydroxyimino) malonic acid dimethyl ester, and no epoxy succinic acid residue.

The above different batches of copolymer and polyepoxysuccinic acid were subjected to scale inhibition and degradation experiments, and the data are shown in tables 1 and 3 below. (conventional polyepoxysuccinic acid S1)

Table 1: results of scale inhibition performance test of different samples

The experiments show that compared with the traditional polyepoxysuccinic acid, the calcium scale inhibition performance of the copolymer provided by the invention is obviously enhanced.

Table 2: data of degradation experiment part of different samples

The experiments show that the copolymer provided by the invention has degradation capability equivalent to that of polyepoxysuccinic acid and can be biodegraded in a shorter time.