CN100509867C - Preparation method for oxygen-containing nitrolic acid structure polyalcohol inphase opposition emulsions - Google Patents

Abstract

The invention relates to a preparation method for polymeric reverse emulsion with hydroxamic acid structure, belonging to the water-soluble polymer synthesis technical field. The method copolymerizes AA-Na and AM in the reverse emulsion with KPS-TMEDA as the oxidation-reduction initiating system, leading to the smooth polymerization at normal temperature, and obtaining the water-soluble polymer with high molecular weight, and then under the strong alkalic condition, the method modifies the polymer with the hydroxylamine in the reverse emulsion, introduces the hydroxamic acid group and obtains a new polymer with good water solubility and temperature-resistance and salt-resistance. The latex is conveniently and high efficiently applied in the flocculation field as aluminium melting, waste water treatment, etc. and the powder products can be obtained after ethanol precipitation, drying and smashing, so the preparation method has broad application prospect in daily chemicals, oil field development and water treatment, etc.

Description

A kind of preparation method of polymer inverse emulsion containing hydroxamic acid structure

technical field

The invention relates to a method for preparing a polymer inverse emulsion containing a hydroxamic acid structure, and belongs to the technical field of water-soluble polymer synthesis.

Background technique

In alumina production, whether it is Bayer method, sintering method, or combined method, a large amount of red mud will be produced, and the sedimentation and separation of red mud is a very important link in the aluminum industry. If conventional anionic, cationic and non-ionic polyacrylamides are used for treatment, they all have disadvantages such as large dosage, small flocs, and poor mud-water separation effect. It is known that the hydroxamic acid functional group has a strong affinity for transition metal elements, especially iron, and iron is ubiquitous on the surface of most mineral particles in red mud, so the polyacrylamide modified product can be quickly absorbed by the hydroxamic acid group. And firmly adhere to the red mud particles to form larger flocs. These flocs are stronger and will not be broken by general agitation, which is beneficial to reduce the turbidity of the supernatant. For this special adsorption , even if it is stirred again, it will not break the flocs and affect the turbidity.

The traditional preparation method of polymers containing hydroxamic acid structure usually adopts solution polymerization and uses conventional initiators. This preparation method has many disadvantages, such as low solid content of the obtained product, slow polymerization rate, poor solubility, no Suitable for low temperature use and difficult industrial implementation.

Contents of the invention

Aiming at the deficiencies in the prior art, the present invention provides a method for preparing an inverse emulsion of a polymer containing a hydroxamic acid structure. By adopting a novel oxidation-reduction initiation system, a high-molecular-weight polymer containing Hydroxamic acid structure polymer latex products can be obtained into powder products after simple treatment.

Technical scheme of the present invention is as follows:

A method for preparing a polymer inverse emulsion containing a hydroxamic acid structure, using a redox initiation system, selecting acrylamide (AM) and sodium acrylate (AA-Na) to copolymerize in an inverse emulsion, aviation kerosene as the continuous phase, and emulsifying The agent is a mixture of octylphenol polyoxyethylene ether (OP 10) and sorbitan oleate (Span 80), water is the dispersed phase, and the reducing agent in the initiation system is tetramethylethylenediamine (TMEDA). The oxidizing agent is potassium persulfate (KPS), and the molar ratio of the oxidizing agent (KPS) to the reducing agent (TMEDA) is 1:0.7-1:1.3. The obtained polymer latex is reacted with hydroxylamine under alkaline conditions, and modified to introduce hydroxamic acid groups. Proceed as follows:

1. Polymerization

(1) Oil phase

Dissolve emulsifiers OP 10 and Span 80 in kerosene, the mass ratio of OP 10 and Span 80 is 1:(6~11), and pass N ₂ under stirring for half an hour to remove oxygen. The volume ratio of kerosene to water is 3:2~1:2, and the amount of Span 80 added is 1.5~4.0g·dL ^-1 relative to the total volume of the system

(2) Water phase

Acrylamide (AM) and sodium acrylate (AA-Na) are mixed and dissolved in water according to the mass ratio (11-8): 1, and the mass ratio of acrylamide (AM) and sodium acrylate (AA-Na) to water is 1 : (4～1), adjust the pH value of the system to 6.5～9, add a reducing agent, and pass _N2 to remove oxygen for half an hour.

(3) According to the oil-water phase volume ratio of 3:2 to 1:2, slowly drop the above water phase into the oil phase, and stir rapidly while dropping to facilitate the emulsification of the system.

(4) Add oxidant potassium persulfate (KPS) after the emulsification of the above system is completed. Relative to the total volume of the system, the amount of KPS added is 1.5-6.5 mmol·L ^-1 , the temperature is 15-60°C, and the pH value of the polymerization system is 6.5 ～12, the polymerization reaction time is 1～20h, the reaction is terminated, and a uniform viscous milky white stable glue is obtained.

2. Modification

The uniform viscous milky white stable glue prepared in the above step 1 is processed, and the steps are as follows:

(1) Oil phase

Dissolve emulsifiers OP 10 and Span 80 in kerosene, the mass ratio of OP 10 to Span 80 is 1:(6~11), and the amount of Span 80 added is 16.0~35.0g·dL ^-1 relative to kerosene.

(2) Water phase

Dissolve hydroxylamine hydrochloride in water (mass ratio of hydroxylamine hydrochloride to water is 1-1:2), dissolve sodium hydroxide in water (mass ratio of sodium hydroxide to water is 1-1:2), and then slowly mix the two solutions ( The mass ratio of the two solutions is 1:0.5 to 1:1.5), to ensure that the exotherm is not too violent, and to control the reaction temperature below 60°C.

(3) The volume ratio of the homogeneous viscous milky white stable glue obtained in the polymerization step and the modified step (1) is 1:1 to 4:1, and the above oil phase is slowly added dropwise to the stable glue, Then slowly add the water phase prepared in the above modification step (2) into the stable glue solution, and stir rapidly while adding, so as to facilitate the emulsification of the system.

(4) After the emulsification of the above system is complete, reduce the stirring speed, control the reaction temperature to 50-90°C, the pH value to 8-14, the modification reaction time to 2-20 hours, and stop the reaction to obtain a uniform viscous milk with a slightly yellowish stable emulsion.

The latex product of the above-mentioned hydroxamic acid type polymer can be directly applied, and the solid can also be precipitated with ethanol, dried, and pulverized to obtain a powder product of the hydroxamic acid type polymer.

In the above inverse emulsion polymerization system, the total monomer concentration (relative to the total volume of the system) is 20-50 g·dL ^-1 , preferably 27-35 g·dL ^-1 . Relative to the total mass number of the two monomers, the mass feed ratio of monomer sodium acrylate (AA-Na) is 1-50%, the best is 5-25%; the monomer acrylamide (AM) mass feed ratio is 1-50%. 99%, the best is 80-95%.

The molar ratio of reducing agent tetramethylethylenediamine (TMEDA) and oxidizing agent potassium persulfate (KPS) in the above-mentioned polymerization initiation system is optimally 1: (0.9～1.1);

The optimum addition amount of the above-mentioned polymerization oxidant potassium persulfate (KPS) relative to the total volume of the system is 1.5-6.5 mmol·L ^-1 .

The optimal volume ratio of kerosene and water in the above polymeric emulsion system is 1:1-2:3; relative to the total volume of the system, the optimal addition amount of emulsifier Span 80 is 1.8-2.3 g·dL ^-1 ; OP 10 and The best mass ratio of Span 80 is 1:(9～11).

The optimum temperature in the above polymerization step (4) is 20-35° C., that is, the polymerization can be successfully initiated at room temperature.

The time in the above-mentioned polymerization step (4) is different according to the monomer ratio and concentration in the polymer system, the concentration of the initiator, the polymer temperature and other conditions, and the time required for the complete polymerization is also different, which can be 1 to 20 hours. Feed under the best conditions, and the best polymerization time is 3 to 6 hours.

The optimum pH value of the above polymerization system is 6.5-8.

In the above modified system, the concentration of hydroxylamine (relative to the total volume of the system) is 7-25 g·dL ^-1 , the best is 10-15 g·dL ^-1 ; the optimum mass ratio of sodium hydroxide/hydroxylamine hydrochloride is (0.85- 1.1): 1.

The volume ratio of kerosene and emulsion in the above modification system is optimally 1:(2~3); relative to kerosene, the optimal addition amount of emulsifier Span 80 is 18.0~25.0g·dL ^-1 , and the optimal amount of OP10 and Span 80 is The best mass ratio is 1:(9~11).

The optimum temperature in the modification step (4) is 65-80°C.

The time in the above-mentioned modification step (4) is different according to the molecular weight of the polymer obtained by polymerization, the degree of hydrolysis, the polymer structure and other conditions, and the time required for the modification is also different completely, which can be 2～20h. Conditional feeding, the best modification time is 4 ~ 7h.

The optimum pH value of the above modification system is 11-13.

The kerosene and sodium acrylate selected in the preparation method of the polymer containing hydroxamic acid structure of the present invention are preferably as follows:

(1) Treatment of kerosene

Adsorb aviation kerosene with activated carbon for more than 4 hours, filter, wash with NaOH aqueous solution, and then wash with distilled water.

(2) Preparation of AA-Na

Adsorb acrylic acid with activated carbon for more than 4 hours, filter; dissolve NaOH in methanol until saturated; slowly add acrylic acid into the methanol solution of NaOH, and keep stirring to fully neutralize the acid and alkali, and react at a low temperature of -4~4 It is carried out at ℃, and the mass ratio of acid to base is 0.9 to 1.0. After the reaction is completed, the reaction solution is filtered with suction, and the obtained solid is the primary product of AA-Na, and then these primary products are washed twice with methanol to obtain the AA-Na raw material that meets the production requirements.

The excellent effects of the present invention are as follows:

1. The raw material is easy to get and the price is cheap.

2. The synthesized polymer has a hydroxamic acid structure, has good salt resistance, and can be used in various flocculation sites.

3. Inverse emulsion polymerization, the polymerization rate is fast, and the prepared polymer has high molecular weight.

4. Due to the use of a new multi-component oxidation-reduction initiation system, the polymerization can be successfully initiated at room temperature to obtain a high molecular weight water-soluble polymer, and the monomer conversion rate is high.

5. The prepared latex can be used directly, which is convenient and efficient; it can also be precipitated with absolute ethanol, dried and pulverized to obtain a powder product, and the organic solvent can be recycled and reused.

The above features indicate that the present invention is suitable for industrial production and has broad application prospects.

Detailed ways

The present invention will be further described below in conjunction with specific examples, but the protection scope of the present invention is not limited thereto.

The monomer used in the following examples and modified feed: acrylamide (AM), analytically pure, Tianjin Kemiou Chemical Reagent Development Center; Acrylic acid (AA), chemically pure, Tianjin Kemiou Chemical Reagent Development Center; Sodium hydroxide, analytically pure, Tianjin Guangcheng Chemical Reagent Co., Ltd.; hydroxylamine hydrochloride, industrial grade.

In the multiple redox initiation system used in the following examples: Potassium persulfate (KPS, oxidizing agent), analytically pure, Tianjin Sitong Chemical Plant; Tetramethylethylenediamine (TMEDA, reducing agent), analytically pure, Shanghai Advance Reagent factory.

Emulsifiers used in the following examples: Span 80, chemically pure, Tianjin Guangcheng Chemical Reagent Co., Ltd.; OP 10, chemically pure, Tianjin Guangcheng Chemical Reagent Co., Ltd.

Other raw materials used in the following examples: aviation kerosene; activated carbon, Tianjin Kemeng Chemical Industry and Trade Co., Ltd.; anhydrous methanol, analytically pure, Tianjin Bodi Chemical Co., Ltd.; absolute ethanol, analytically pure, Jinan Juye, Shandong chemical co., ltd.

The preparation of embodiment 1. sodium acrylate (AA-Na)

Weigh 23.7g of sodium hydroxide, pour it into a 400mL three-neck flask equipped with a condenser, a constant pressure dropping funnel, and an electric stirrer, then put it into a constant temperature ice-water bath at 0°C, add 100g of anhydrous methanol, and start stirring. Adsorb acrylic acid with activated carbon for more than 4 hours, filter, and after the sodium hydroxide in methanol is completely dissolved, weigh 41.4g of filtered acrylic acid and pour it into a constant pressure dropping funnel, slowly drop it into a three-necked bottle, and drop it in 0.5 hours. After the reaction was completed, it was poured into a Buchner funnel to filter, rinsed three times with anhydrous methanol, and dried in a vacuum oven at 50° C. for 24 hours to obtain 50.3 g of a white powder product with a yield of ≥93.1%.

Embodiment 2. the preparation that contains hydroxamic acid structure polymer

Polymerization part: oil phase: Measure 40mL kerosene, weigh 2.0g Span 80 and 0.2g OP10 to dissolve, add to a four-neck flask equipped with stirring, condenser, nitrogen pipe and dropping funnel, and pass _N2 under stirring Deoxygenation for half an hour. Water phase: Weigh 27.0g AM and 3.3g AA-Na and dissolve in 60mL water, then add 0.6mL (0.15mol·L ^-1 ) of TMEDA, and deoxygenate with N ₂ for half an hour. In the case of high-speed stirring (speed ≥ 1100r/min), slowly add the water phase to the oil phase dropwise, 30 ~ 60min dropwise, and finally add KPS 0.033g (dissolved in 2mL water), stir quickly for 20min and then reduce the stirring speed Adjust to about 300r/min, and at the same time transfer to 30°C constant temperature water bath to react for 5h to obtain uniform viscous milky white latex.

Modified part: Oil phase: Measure 40mL kerosene, weigh 10.0g Span 80 and 1.2g OP10 to dissolve and add to the dropping funnel, under the condition of high-speed stirring (speed ≥ 1100r/min), slowly put the oil phase Add it dropwise into the emulsion, and complete the dropwise addition in 30 minutes. Water phase: Weigh 20g of hydroxylamine hydrochloride and dissolve in 30g of water, 20g of sodium hydroxide in 30g of water, slowly mix the two solutions, stir continuously, add to the dropping funnel after the precipitate is dissolved, and stir at a high speed (rotating speed ≥1100r/min), slowly drop the water phase into the emulsion, and finish adding in 30 minutes. After stirring rapidly for 20 minutes, adjust the stirring speed to about 300r/min, and at the same time transfer to a constant temperature water bath at 70°C to react for 5 hours to obtain a uniform, viscous, slightly yellow latex. Precipitate with absolute ethanol, wash, dry, pulverize to obtain amphoteric copolymer powdery product 25.3g, intrinsic viscosity 8.4dL·g ^-1 , settling time 31.7s (the measurement of intrinsic viscosity is carried out according to the regulation of 8.1 in GB 12005.1; intrinsic viscosity The results are indicated according to the provisions of 9.1 in GB 12005.1).

Determination of settling time: Prepare a sample with a mass ratio of 0.1%; add 8g of red mud to 110mL of mine simulation liquid, and stir at 90°C for 0.5h; Mix for 1min at a frequency of 30 times (one upside down and one upside down) for 1min, then add 2.2mL sample, after upside down 30 times, stand still and start the stopwatch at the same time, record the time when the flocs fall to the 60mL scale, which is the sedimentation time.

Example 3. As described in Example 2, the difference is that the monomer feed ratio is changed to AM 30.0g, AA-Na 4.0g, hydroxylamine hydrochloride 22.5g, sodium hydroxide 23.0g, to obtain 26.1g of amphoteric copolymer powder product , the intrinsic viscosity is 8.7dL·g ^-1 , and the settling time is 29.5s.

Example 4. As described in Example 2, the difference is that the monomer feed ratio is changed to AM 30.0g, AA-Na 4.0g, hydroxylamine hydrochloride 22.5g, sodium hydroxide 24.0g, to obtain 26.3g of amphoteric copolymer powder product , the intrinsic viscosity is 9.8dL·g ^-1 , and the settling time is 27.3s.

Example 5. As described in Example 2, the difference is that the monomer feed ratio is changed to AM 27.0g, AA-Na 8.0g, and the amphoteric copolymer powder product 23.7g is obtained, and the intrinsic viscosity is 6.2dL g ^-1 , settling time 37.6s.

Claims (6)

1. the preparation method of an oxygen-containing nitrolic acid structure polyalcohol inphase opposition emulsions, it is characterized in that, adopt redox initiation system, select sodium acrylate and acrylamide monomer copolymerization in reversed-phase emulsion, kerosene is external phase, and sorbitan monooleate and polyoxyethylene octylphenol ether are compound emulsifying agent, water is disperse phase, reductive agent in the initiator system is a Tetramethyl Ethylene Diamine, and oxygenant is a Potassium Persulphate, and oxygenant and reductive agent mol ratio are 1:0.7～1:1.3; Step is as follows:

One, polymerization

(1) oil phase

Emulsifying agent polyoxyethylene octylphenol ether and sorbitan monooleate are dissolved in the kerosene, and polyoxyethylene octylphenol ether and sorbitan monooleate mass ratio are 1:6～1:11, under agitation logical N ₂Deoxygenation half an hour, with respect to the system cumulative volume, the dosage of sorbitan monooleate is 1.5～4.0gdL ^-1

(2) water

Acrylamide and sodium acrylate are dissolved in the water gaging that feeds intake by mass ratio 11:1～8:1 mixing, and the gross weight of acrylamide and sodium acrylate and the mass ratio of water are 1:4～1:1, and pH value to 6.5～9 of regulation system add reductive agent, logical N ₂Deoxygenation half an hour;

(3) press profit phase volume ratio 3:2～1:2, above-mentioned water is added dropwise in the oil phase slowly, stir fast, be convenient to system emulsification while dripping;

(4) treat that above-mentioned system emulsification adds the oxygenant Potassium Persulphate in the back well, with respect to the system cumulative volume, the Potassium Persulphate dosage is 1.5～6.5mmolL ^-1, 15～60 ℃ of temperature, the pH value of polymerization system is 6.5～12, polymerization reaction time 1～20h, the stopping of reaction gets homogeneous thickness oyster white and stablizes glue;

Two, modification

The homogeneous thickness oyster white that above-mentioned steps one is made is stablized glue and is carried out modification and handle, and step is as follows:

(1) oil phase

Emulsifying agent polyoxyethylene octylphenol ether and sorbitan monooleate are dissolved in the kerosene, and polyoxyethylene octylphenol ether and sorbitan monooleate mass ratio are 1:6～1:11, and with respect to kerosene, the dosage of sorbitan monooleate is 16.0～35.0gdL ^-1

(2) water

Oxammonium hydrochloride is water-soluble, and oxammonium hydrochloride is 1:1～1:2 with the quality ratio, and sodium hydroxide is water-soluble, sodium hydroxide is 1:1～1:2 with the quality ratio, two solution are slowly mixed, two solution qualities are than being 1:0.5～1:1.5 again, and control reaction temperature is below 60 ℃;

(3) the homogeneous thickness oyster white that makes by polymerization procedure is stablized the oil phase volume ratio 1:1～4:1 that makes in glue and the modification procedure (1), above-mentioned oil phase is added dropwise to slowly stablizes in the glue, again the water that makes in the above-mentioned modification procedure (2) is added dropwise to slowly and stablizes in the glue, stir fast while dripping, be convenient to system emulsification;

(4) treat that above-mentioned system emulsification is good after, reduce stirring velocity, 50～90 ℃ of control reaction temperature, pH value 8～14, modified-reaction time 2～20h, the stopping of reaction, must homogeneous thickness breast stable yellow emulsion slightly.

2. the preparation method of oxygen-containing nitrolic acid structure polyalcohol inphase opposition emulsions as claimed in claim 1 is characterized in that, in the polymerization system, with respect to the system cumulative volume, total monomer is 20～50gdL in the reversed-phase emulsion copolymerization ^-1Relative two kinds of monomeric total mass numbers, wherein monomer sodium acrylate quality feed ratio is 1～50%, monomer acrylamide quality feed ratio is 1～99%; In the modified system, with respect to the system cumulative volume, azanol concentration is for being 7～25gdL ^-1, sodium hydroxide and quality of oxammonium hydrochloride feed ratio are 0.85:1～1.1:1.

3. the preparation method of oxygen-containing nitrolic acid structure polyalcohol inphase opposition emulsions as claimed in claim 1 is characterized in that, in the described polymerization system, the volume ratio of kerosene and water is 1:1～2:3; With respect to the system cumulative volume, the add-on of emulsifying agent sorbitan monooleate is 1.8～2.3gdL ^-1Polyoxyethylene octylphenol ether and sorbitan monooleate mass ratio are 1:9～1:11.

4. the preparation method of oxygen-containing nitrolic acid structure polyalcohol inphase opposition emulsions as claimed in claim 1 is characterized in that, in the described modified system, the volume ratio of kerosene and emulsion is 1:2～1:3; With respect to kerosene, the add-on of emulsifying agent sorbitan monooleate is 18.0～25.0gdL-1, and polyoxyethylene octylphenol ether and sorbitan monooleate mass ratio are 1:9～1:11.

5. the preparation method of oxygen-containing nitrolic acid structure polyalcohol inphase opposition emulsions as claimed in claim 1 is characterized in that, temperature is 20～35 ℃ in the described polymerization procedure (4); Temperature is 65～80 ℃ in the modification procedure (4).

6. the preparation method of oxygen-containing nitrolic acid structure polyalcohol inphase opposition emulsions as claimed in claim 1 is characterized in that, the pH value of described polymerization system is 6.5～8; The pH value of modified system is 11～13.