CN103030730B - Preparation method of dispersing agent containing sulfo polycarboxylate - Google Patents

Abstract

The invention relates to a preparation method of a dispersing agent containing sulfo polycarboxylate. The method comprises the steps that acrylamide-2-methyl propanesulfonic acid, acrylic acid, and 2-acryamide-2-methyl propanesulfonic acid are copolymerized in an aqueous solution; persulfate serves as an initiating system; and the water-soluble polymer dispersing agent is formed. The polymer dispersing agent contains sulfonic groups, and has good heat resistance, salt tolerance and environmental adaptability. The method is simple and practicable, short in production cycle, safe and environment-friendly; and the prepared dispersing agent is used for dispersing iron oxide, titanium dioxide, and atrazine in circulating water.

Description

A kind of preparation method of polycarboxylate dispersant containing sulfonic acid group

technical field

The method relates to an inorganic powder and a pesticide dispersant and a preparation method thereof, in particular to a preparation method of a sulfonic acid group-containing polycarboxylate dispersant.

Background technique

Dispersants are widely used in paints, printing inks, rubber, coal water slurry, cement, papermaking, pesticides and the preparation of nanoparticles, etc., but the existing small molecule dispersants and homopolymer dispersants (such as sodium polyacrylate, molecular weight -6000) The dispersion performance is not very ideal, and it is impossible to obtain a suspension with a high suspension ratio, but the multi-component copolymerization polymer dispersant can combine the characteristics of various monomers, and significantly improve the dispersion performance of the polymer.

CN101475671A provides a comb-shaped copolymer cement dispersant, which has the advantages of low dosage and strong adaptability. The preparation step of the comb copolymer cement dispersant comprises: monomer A represented by general formula (1) and monomer B represented by general formula (2) undergo free radical copolymerization in aqueous medium, wherein A and B The molar ratio is 1:2 to 1:10. The present invention reduces the sensitivity of the graft copolymer adsorption characteristics to ion species and content in the cement slurry by introducing sulfonic acid groups into the main chain of the graft copolymer and using the sulfonic acid groups as the adsorption group. Sensitivity to sulfate ions, thereby improving the adaptability of graft copolymer dispersants in construction projects. The invention has simple preparation process, low product dosage and strong cement adaptability, but the raw materials methoxypolyethylene glycol monomethacrylate and methoxypolyethylene glycol monoacrylate are relatively high and expensive, and The holding time in the polymerization reaction is longer. However, the dispersion effect of copolymer dispersants on pesticides, pigments, dyes and coal water slurry is not ideal.

Contents of the invention

The invention provides a preparation method of a sulfonic acid group-containing polycarboxylate dispersant. The polymer dispersant is used as a dispersant in inorganic powders and pesticides, and can effectively improve the uniformity and stability of the system. And the raw material is simple and easy to get, and the price is low.

Technical scheme of the present invention is as follows:

A preparation method of polycarboxylate dispersant containing sulfonic acid groups, the mass fraction of monomers consists of: 30-55% acrylic acid, 15-40% 1-hydroxypropyl acrylate, 2-acrylamide-2-methyl Propanesulfonic acid 15-50%, the total mass fraction of the three monomers is 100%; the steps are as follows:

(1) Add 2-acrylamido-2-methylpropanesulfonic acid (AMPS) into water, add chain transfer agent, stir while heating, control the temperature at 55-60°C, and remove oxygen in the system by blowing nitrogen.

(2) When the temperature is raised to 62-68°C, add dropwise the mixed monomer aqueous solution A and initiator aqueous solution B of acrylate-1-hydroxypropyl acrylate and acrylic acid;

(3) After the dropwise addition, the temperature is raised to 70-90° C., and the reaction is kept for 1-3 hours.

(4) Cool naturally to below 30°C, adjust the pH of the reaction solution to 7-8 with sodium hydroxide solution; obtain a polymer solution, which is a dispersant. It can be used as a dispersant for direct industrial application.

Preferably according to the present invention, also comprise the following steps:

(5) Drop the polymer solution obtained in step (4) into acetone drop by drop, and replace the acetone every 3-4 hours after soaking for a total of 4-6 times; at this time, the polymer hardens into a solid; break the solid polymer , put it into a constant temperature vacuum drying oven, and dry it at a temperature of 35-45°C to obtain a dispersant powder.

Preferably according to the present invention, the chain transfer agent is isopropanol, and the added amount is 3-20% of the total mass of the monomers.

Preferably according to the present invention, the mass ratio of step (1) 2-acrylamido-2-methylpropanesulfonic acid (AMPS) to water is 1:6-12.

Preferably according to the present invention, in step (1), nitrogen gas is passed for 30-40 minutes.

Preferably according to the present invention, the water in steps (1) and (2) are both tertiary water.

Preferably according to the present invention, the initiator in step (2) is ammonium persulfate, potassium persulfate or sodium persulfate, and the amount added is 3-20% of the total mass of the monomers. Among them, ammonium persulfate is particularly preferred.

Preferably according to the present invention, the mass concentration of 1-hydroxypropyl acrylate and acrylic acid in the mixed monomer aqueous solution A of 1-hydroxypropyl acrylate and acrylic acid in step (2) is 30-60%. The initiator mass fraction in the initiator aqueous solution B is 8-10%.

Preferably according to the present invention, the sodium hydroxide solution in step (4) is a sodium hydroxide solution with a mass fraction of 34-36%.

Preferably according to the present invention, in step (2), the time for adding the mixed monomer aqueous solution A is 0.5-1 h, and the time for adding the initiator solution is 1-2 h.

The present invention selects 2-acrylamido-2-methylpropanesulfonic acid monomer, which has high reactivity, and the molecular weight of the dispersant is easy to regulate, and the prepared ternary polymer dispersant has good adaptability, and is resistant to iron oxide, titanium dioxide, pesticides Atrazine has good dispersibility and can be widely used in industrial circulating water, papermaking, pesticides and other fields.

Compared with the existing production technology, the synthesis process has the following significant advantages:

1) The raw material of the polymer dispersant is easy to obtain, the price is low, and the monomers are all soluble in water, and the polymer also has good water solubility, which is especially suitable for dispersing the system under the water environment.

2) The polymer dispersant contains sulfonic acid groups, so it has good temperature and salt resistance, good effect on acid-base system, and good environmental adaptability.

3) The production of the polymer dispersant requires simple equipment, and the production process is simple and easy; the production cycle is short; no three wastes are generated, which is safe and environmentally friendly; the reaction solution can be used directly, and the product is safe and stable.

detailed description

Reagents, materials, etc. used in the following examples, if no special instructions, can be obtained from commercial sources

The actual source of raw materials, acrylic acid was purchased from Tianjin Damao Chemical Reagent Factory; 2-acrylamido-2-methylpropanesulfonic acid AMPS was purchased from Weifang Quanxin Chemical Factory; 1-hydroxypropyl acrylate was purchased from West Asia Reagent; Ammonium was purchased from Sinopharm Chemical Reagent Co., Ltd.; sodium hydroxide was purchased from Sinopharm Chemical Reagent Co., Ltd.; titanium dioxide was purchased from Sinopharm Chemical Reagent Co., Ltd.; ferrous sulfate heptahydrate was purchased from Tianjin Guangcheng Chemical Reagent Co., Ltd. from Beijing Chemical Plant; isopropanol was purchased from Tianjin Dengke Chemical Reagent Co., Ltd.; tertiary water: self-made in the laboratory (Youpu ultrapure water manufacturing system).

Example 1

One, the preparation of dispersant, the steps are as follows:

Preparation of solution A: Add 4.3236g of acrylic acid and 2.6028g of 1-hydroxypropyl acrylate into 17.5mL of water three times, and record it as solution A);

Preparation of solution A: Add 0.5130g of ammonium persulfate into 5.13mL of water, stir to dissolve, and record it as solution B.

Add 3.3158g AMPS to a four-neck flask equipped with a thermometer, stirrer, nitrogen tube, Y-shaped tube, and constant pressure dropping funnel, add 29mL three times of water, and then add 1.305mL isopropanol, heat up to 60°C, stir and pass Nitrogen for 30min. The temperature was raised to 65°C, and solution A and solution B were added drop by drop. Solution A was dropped in about 1 hour, and solution B was dropped in about 1.5 hours. The temperature was raised to 70° C., and the reaction was kept for 2.5 hours. After the solution is cooled below 30°C, add dropwise a 35% sodium hydroxide solution to adjust the pH to 7-8. The obtained polymer solution can be used as a dispersant.

Drop the obtained polymer solution into acetone drop by drop, soak for 4 hours and change the acetone once, after changing 6 times, the polymer becomes hard, crush it, put it into a constant temperature vacuum drying oven (temperature is 40°C) and dry to obtain a dispersant powder.

Two, the dispersant obtained in embodiment 1 is to the dispersibility test of inorganic powders such as titanium dioxide

Add 0.4g of dispersant powder and 50mL of water three times into a 100mL beaker, stir to dissolve, and then add 0.1mol/L sodium hydroxide solution and 0.1mol/L hydrochloric acid solution drop by drop to adjust the pH of the solution to 7. Then add 1.0000g of dried and ground TiO ₂ , shear and emulsify at a rate of 5kr/min for 15min, then transfer to a 100mL stoppered measuring cylinder, add water three times to 100mL, and turn it upside down 30 times (180° upside down is 1 time), put the measuring cylinder vertically in a 30°C water bath (no vibration, no direct sunlight), transfer the upper 90mL suspension with the pipette, and transfer the remaining suspension and sediment to the cuvette (the cuvette has been weighed as M ₁ ). Dry the watch glass in an oven, weigh the mass as M ₂ , and calculate the mass of insoluble matter M=M ₂ -M ₁ .

In the formula, 1.4000g is the mass of the dispersant and _TiO2 particles in the stoppered measuring cylinder.

According to the suspension rate test method, the suspension rate of the dispersant in Example 1 to the titanium dioxide suspension is 65.29%.

Three, embodiment 1 gained dispersant is to the dispersibility determination of ferric oxide in cooling circulating water

The light transmittance reflects the turbidity of the solution, and the performance of the polymer dispersed iron oxide is evaluated by the light transmittance.

FeSO ₄ 7H ₂ O generates Fe(OH) ₂ in alkaline solution, and Fe(OH) ₂ is oxidized to eventually generate Fe ₂ O ₃ , if the dispersion performance of the polymer is poor, the oxide will precipitate, and the light transmittance of the solution Just big. Conversely, the smaller the light transmittance, the better the dispersion performance of the polymer.

Test steps:

Prepare 50 mL of solution: p(Ca ²⁺ )=150 mg/L, p(Fe ²⁺ )=10 mg/L, pH=9.0, a certain amount of polymer. Stir magnetically for 15 minutes, let stand, keep the temperature at 50°C for 5 hours, and cool. Take the upper layer solution, and measure the light transmittance T of the solution with a spectrophotometer at 420 nm and a 3 cm colorimetric cell.

The light transmittance of the iron oxide suspension in Example 1 was measured as 36.55% according to the above light transmittance measurement method.

Four, embodiment 1 dispersant measures the dispersibility of pesticide Atrazine

Dissolve 0.1000g of dispersant powder and 0.0500g of sodium lauryl sulfate in 50mL of water three times. After fully dissolving, add 1.0000g of the original pesticide. The whole system was emulsified in a high-shear dispersing emulsifier for 15 minutes (speed 5kr/min). After emulsification, the whole system was transferred into a 100mL measuring cylinder with a stopper, and water was added three times to 100mL, and turned upside down 30 times, (upside down 180 °Return to the original position for 1 time). Place the graduated cylinder vertically in a water bath at 30°C without vibration or direct sunlight. After 30 minutes, remove the upper 90mL suspension with a straw, and transfer the remaining 10mL suspension and sediment to _a weighed M1 Wash the graduated cylinder with distilled water to ensure that all the sediment in the graduated cylinder is transferred to the watch glass, put the watch glass into a vacuum drying oven (the temperature is controlled at 60°C) to dry, and weigh M ₂ to calculate the insoluble The mass M of the substance, M=M ₂ -M ₁ , is used to determine its suspension rate.

According to the above formula for determining the suspension rate, the suspension rate of the self-made dispersant to the atrazine suspension was measured to be 90.49%.

Example 2

Add 4.3236 g of acrylic acid and 2.6028 g of 1-hydroxypropyl acrylate into 11.5 mL of three times of water, add 1.025 g of ammonium persulfate into 10.25 mL of three times of water, stir and dissolve to obtain a mixed monomer solution.

Add 0.5130g of ammonium persulfate into 5.13mL of water, stir and dissolve to obtain an initiator solution.

Add 3.3158g AMPS to a four-necked flask equipped with a thermometer, stirrer, nitrogen tube, Y-shaped tube, and constant pressure dropping funnel, add 29.5mL of water for three times, then add 1.305mL of isopropanol, heat up to 58°C, and pass Nitrogen for 30min. Raise the temperature to 68°C, add the mixed monomer solution and initiator solution drop by drop, the mixed monomer solution drops in about 1 hour, and the initiator solution drops in about 1.5 hours. The temperature was raised to 80° C., and the reaction was kept for 2.5 hours. After the solution is cooled below 30°C, add dropwise a 35% sodium hydroxide solution to adjust the pH of the solution to 7-8. Drop the obtained solution into acetone, soak for 4 hours and replace the acetone once, and replace it 5 times After the polymer becomes hard, smash it into pieces, put it into a constant temperature vacuum drying oven (at a temperature of 40°C) and dry it to obtain a dispersant powder.

According to embodiment 1 dispersibility test method, the light transmittance of the dispersant to the iron oxide suspension is 30.08%, the suspension rate of the _TiO suspension is 80.53%, and the suspension rate of the atrazine suspension is 89.06%. %.

Example 3

Add 4.3236 g of acrylic acid and 2.6028 g of 1-hydroxypropyl acrylate into 11.5 mL of water three times to obtain a mixed monomer solution; add 1.190 g of ammonium persulfate into 11.90 mL of water, stir and dissolve to obtain an initiator solution.

Add 4.974g AMPS to a four-necked flask equipped with a thermometer, stirrer, nitrogen tube, Y-shaped tube, and constant pressure dropping funnel, add 46.5mL of water for three times, then add 2.271mL of isopropanol, raise the temperature to 60°C, and blow nitrogen 30min. Raise the temperature to 67°C, add the mixed monomer solution and initiator solution drop by drop, the mixed monomer solution will be dropped in about 1 hour, and the initiator solution will be dropped in about 1.5 hours. The temperature was raised to 70° C., and the reaction was kept for 2.5 hours. After the solution is cooled below 30°C, add dropwise a 35% sodium hydroxide solution to adjust the pH to 7-8. The obtained solution was dropped into acetone drop by drop, soaked for 4 hours and replaced with acetone once, and the polymer hardened after 6 times of replacement, crushed, put into a constant temperature vacuum drying oven (temperature 40°C) and dried to obtain a dispersant.

According to embodiment 1 dispersibility testing method, the dispersant is 28.36% to the light transmittance of iron oxide suspension, to _TiO The suspension rate of suspension is 77.33%, to the suspension rate of Atrazine suspension is 89.79% %.

Example 4

Add 4.3236g of acrylic acid and 2.6028g of 1-hydroxypropyl acrylate into 11.5mL of water three times to obtain a mixed monomer solution; add 1.356g of ammonium persulfate into 13.56mL of water, stir and dissolve to obtain an initiator solution.

Add 6.632g AMPS to a four-neck flask equipped with a thermometer, stirrer, nitrogen tube, Y-shaped tube, and constant pressure dropping funnel, add 43mL of water for three times, then add 0.863mL of isopropanol, raise the temperature to 58°C, and blow nitrogen After 30 minutes, the temperature was raised to 68°C, and the mixed monomer solution and initiator solution were added drop by drop. The mixed monomer solution was dropped in about 1 hour, and the initiator solution was dropped in about 1.5 hours. The temperature was raised to 90° C., and the reaction was kept for 2 hours. After the solution is cooled below 30°C, add dropwise a 35% sodium hydroxide solution to adjust the pH to 7-8. Drop the obtained solution into acetone drop by drop, soak for 4 hours and change the acetone once, after changing 4-6 times, the polymer becomes hard, crush it, put it into a constant temperature vacuum drying oven (temperature is 40°C) and dry it, and the obtained the dispersant.

According to embodiment 1 dispersibility test method, the light transmittance of the dispersant to the iron oxide suspension is 27.72%, the suspension rate of _TiO2 suspension is 76.10%, and the suspension rate of Atrazine suspension is 91.80%. %.

Example 5

Add 4.3236g of acrylic acid and 2.6028g of 1-hydroxypropyl acrylate into 11.5mL of water three times to obtain a mixed monomer solution; add 1.356g of ammonium persulfate into 13.56mL of water, stir and dissolve to obtain an initiator solution.

Add 6.632g AMPS to a four-necked flask equipped with a thermometer, stirrer, nitrogen tube, Y-shaped tube, and constant pressure dropping funnel, add 36mL of water for three times, then add 2.587mL of isopropanol, heat up to 55°C, and blow nitrogen for 30min . , the temperature was raised to 65°C, and the mixed monomer solution and initiator solution were added dropwise. The mixed monomer solution was dropped in about 1 hour, and the initiator solution was dropped in about 1.5 hours. The temperature was raised to 80° C., and the reaction was kept for 2.5 hours. After the solution is cooled below 30°C, add dropwise a 35% sodium hydroxide solution to adjust the pH to 7-8. Drop the obtained solution into acetone drop by drop, soak for 4 hours and change the acetone once, after changing 4-6 times, the polymer becomes hard, crush it, put it in a constant temperature vacuum drying oven (temperature is 40°C) and dry it to get the dispersant .

According to embodiment 1 dispersibility test method, record this dispersant to the light transmittance of ferric oxide suspension 35.54%, to _TiO The suspension rate of suspension 93.24%, to the suspension rate of atrazine suspension 84.36% %.

Example 6

Add 4.3236g of acrylic acid and 2.6028g of 1-hydroxypropyl acrylate into 11.5mL of water three times to obtain a mixed monomer solution; add 2.034g of ammonium persulfate into 20.34mL of water, stir and dissolve to obtain an initiator solution.

Add 6.632g AMPS to a four-neck flask equipped with a thermometer, a stirrer, a nitrogen tube, a Y-shaped tube, and a constant pressure dropping funnel, add 36mL of three times water, and then add 1.726mL of isopropanol, raise the temperature to 56°C and pass nitrogen gas for 30min. Raise the temperature to 68°C, add the mixed monomer solution and initiator solution drop by drop, the mixed monomer solution drops in about 1 hour, and the initiator solution drops in about 1.5 hours. The temperature was raised to 75° C., and the reaction was kept for 2.5 hours. After the solution is cooled below 30°C, add dropwise a 35% sodium hydroxide solution to adjust the pH to 7-8. Drop the obtained solution into acetone drop by drop, soak for 4 hours and change the acetone once, after changing 4-6 times, the polymer becomes hard, crush it, put it into a constant temperature vacuum drying oven (temperature is 40°C) and dry it, and the obtained the dispersant.

According to embodiment 1 dispersibility test method, record this dispersant to the light transmittance of ferric oxide suspension 94.70%, to TiO _2The suspension rate of suspension is 82.27%, to the suspension rate of Atrazine suspension 86.43% %.

Claims (5)

1. A method for preparing a sulfonic acid group-containing polycarboxylate dispersant for inorganic powder iron oxide, titanium dioxide and the pesticide atrazine. The monomer mass fraction is composed of: acrylic acid 30-55%, acrylic acid-1 -Hydroxypropyl ester 15-40%, 2-acrylamido-2-methylpropanesulfonic acid 15-50%, the total mass fraction of the three monomers is 100%; the steps are as follows: (1) Add 2-acrylamido-2-methylpropanesulfonic acid (AMPS) into water three times, add chain transfer agent, stir while heating, control the temperature at 55-60°C, and remove oxygen in the system by blowing nitrogen; The mass ratio of the 2-acrylamido-2-methylpropanesulfonic acid (AMPS) to tertiary water is 1:6-12; Described chain transfer agent is Virahol, and addition is the 3-20% of monomer mass summation; (2) When the temperature is raised to 62-68°C, add dropwise the mixed monomer aqueous solution A and initiator aqueous solution B of 1-hydroxypropyl acrylate and acrylic acid; Initiator mass fraction in described initiator aqueous solution B is 8-10%; The dropping time of the mixed monomer aqueous solution A is 0.5-1h, and the dropping time of the initiator solution B is 1-2h; (3) After the dropwise addition, the temperature is raised to 70-90° C., and the heat preservation reaction is performed for 1-3 hours; (4) Cool naturally to below 30°C, adjust the pH of the reaction solution to 7-8 with sodium hydroxide solution; obtain a polymer solution, which is a dispersant; (5) Drop the polymer solution obtained in step (4) into acetone drop by drop, and replace the acetone every 3-4 hours after soaking for a total of 4-6 times; at this time, the polymer hardens into a solid; break the solid polymer , put it into a constant temperature vacuum drying oven, and dry it at a temperature of 35-45°C to obtain a dispersant powder. 2. The preparation method of the dispersant as claimed in claim 1, characterized in that, in step (2), the initiator is ammonium persulfate, potassium persulfate or sodium persulfate, and the addition amount is 3-20% of the total mass of monomers. %. 3. the preparation method of dispersant as claimed in claim 1 is characterized in that, in step (2) in the mixed monomer aqueous solution A of -1-hydroxypropyl acrylate and acrylic acid, the mixture of -1-hydroxypropyl acrylate and acrylic acid The mass concentration is 30-60%. 4. The method for preparing a dispersant according to claim 1, wherein the sodium hydroxide solution in step (4) is a sodium hydroxide solution with a mass fraction of 34-36%. 5. the preparation method of dispersant as claimed in claim 1, is characterized in that, step is as follows: Add 4.3236g of acrylic acid and 2.6028g of 1-hydroxypropyl acrylate into 17.5mL of water three times, and record it as solution A; Add 0.5130g of ammonium persulfate into 5.13mL of water, stir to dissolve, and record it as solution B; Add 3.3158g of 2-acrylamido-2-methylpropanesulfonic acid (AMPS) into a four-neck flask equipped with a thermometer, a stirrer, a nitrogen tube, a Y-shaped tube, and a constant pressure dropping funnel, add 29 mL of water three times, and then Add 1.305mL of isopropanol, raise the temperature to 60°C, stir and blow nitrogen for 30min; raise the temperature to 65°C, add solution A and solution B drop by drop, solution A takes 1 hour to finish, solution B takes 1.5 hours to finish dropping; heat up To 70°C, keep warm for 2.5 hours; after the solution is cooled below 30°C, add dropwise a 35% sodium hydroxide solution to adjust the pH to 7-8; obtain a polymer solution, which can be used as a dispersant; Drop the obtained polymer solution into acetone drop by drop, soak for 4 hours and change the acetone once, after changing 6 times, the polymer becomes hard, crush it, put it in a constant temperature vacuum drying oven, and dry it at 40°C to get a dispersant powder .