CN101993210B - Prenyl polyether polycarboxylate water reducing agent and synthesis method thereof - Google Patents

Abstract

The present invention provides a kind of isoprenyl polyether polycarboxylate water reducer, which is isoprenyl polyoxyethylene ether or isoprenyl polyoxyethylene propylene ether (macromonomer A) The polymer with unsaturated carboxylic acid and its derivative (small monomer B) belongs to the field of concrete admixture. The synthesis method is that the large monomer A and the small monomer B are initiated by a redox initiation system at a relatively low temperature with water as a solvent, and are obtained through copolymerization under the action of a chain transfer agent. This kind of water reducing agent overcomes the disadvantages of low water reducing rate, poor slump retention, and long setting time of the water reducing agent synthesized by allyl polyoxyethylene ether. It has high slump retention, large water reduction, and little influence on the setting time of concrete. advantage.

Description

Isoprenyl polyether polycarboxylate water reducer and synthesis method thereof

technical field

The invention relates to a concrete water reducer, in particular to an isoprenyl polyether polycarboxylate water reducer and a synthesis method thereof.

Background technique

The water reducing agent is used in concrete, which can reduce the water required for cement hardening, has a strong dispersion effect on cement, makes the physical structure of concrete more uniform after solidification, and improves the strength of concrete. The development of water reducers mainly has three stages: the first generation is an ordinary water reducer represented by lignosulfonate; the second generation is a high-efficiency water reducer represented by naphthalene sulfonate; the third generation is a High-performance water reducer represented by polycarboxylate.

The polycarboxylate superplasticizer with polyether side chain is the latest research achievement at present, it has high dispersion performance and good slump retention performance at low dosage; in addition, its degree of freedom in molecular structure Large, diverse synthesis techniques, great potential for high performance.

At present, the patent documents of polycarboxylate high-performance water reducers at home and abroad are mainly polyether polycarboxylate water reducers of unsaturated alcohols. The esterification water reducer of (meth)acrylic acid has a high water reducing rate and good slump retention, but the polyester macromonomer must first undergo the esterification reaction of a macromolecular alcohol and a small molecule unsaturated acid, and this step is difficult to synthesize Large, the intermediate separation and purification process is relatively complicated, the raw material of the synthesized macromonomer is unstable, and the industrialization cost is relatively high. The synthesis process of polyether polycarboxylate superplasticizer of unsaturated alcohol is simple. The unsaturated polyether macromonomer is mainly carried out through industrial ethoxylation reaction equipment, and only one-step ring-opening polymerization is required without separation. , the product has high purity, and the follow-up polymerization process is simple. The products currently on the market are mainly allyl polyoxyethylene ethers. This type of polyether has low activity and can only be better copolymerized with maleic anhydride. The synthesized product The water-reducing rate is low, the slump-retaining performance is general, and due to the dicarboxylic groups of maleic anhydride, this type of polycarboxylate superplasticizer has a greater impact on the hydration of cement; the currently reported product is methallyl poly Oxyethylene ether, this type of polyether has high activity and can be well copolymerized with small acrylic monomers. The synthesized water reducer has a high water reducing rate, good slump retention performance, and good adaptability to various cements. However, the initiator used in its synthesis is methallyl alcohol, which has a complicated synthesis process and high price, and belongs to fine chemicals, which limits its large-scale promotion and use.

Contents of the invention

The object of the present invention is to provide a kind of isoprenyl polyether type polycarboxylate water reducer and its synthesis method, the macromonomer used in this water reducer not only has high activity, but also can carry out the reaction with acrylic small monomer Better copolymerization, the synthesized water reducing agent has higher water reducing rate, good slump retention performance, good adaptability to various cements, and the synthesis process of the initiator used in the synthesis of its macromonomer is simple and the price is low. Easy to promote.

A kind of isoprenyl polyether polycarboxylate water reducing agent provided by the present invention, it is isoprenyl polyoxyethylene ether or isoprenyl polyoxyethylene propylene ether (A) and unsaturated The polymkeric substance of carboxylic acid or derivative (B) thereof, represents macromonomer A with formula (1), represents small monomer B with formula (2) as follows:

Among them: R ₁ -hydrogen atom or an alkyl group with 1 to 5 C atoms

m-the number of repeating units is 5 to 200

n-the number of repeating units is 0 to 100,

Among them: R ₂ -hydrogen atom or an alkyl group with 1 to 5 C atoms

R ₃ -hydroxyl group, amino group or an alkyl group with 1 to 5 C atoms.

The synthesis of the above polycarboxylate high-performance water reducer is obtained by initiating the macromonomer A and small monomer B with a redox initiation system, and undergoing a copolymerization reaction under the action of a chain transfer agent.

The specific steps include: dissolving the macromonomer A in deionized water, heating up while stirring, when the temperature rises to 30-50°C, adding an oxidant, and when the temperature reaches 60-80°C, simultaneously dropwise adding the small monomer B aqueous solution and For the mixed aqueous solution of reducing agent and chain transfer agent, the time for adding the small monomer B aqueous solution is controlled within 2 to 4 hours, and the time for adding the mixed aqueous solution of reducing agent and chain transfer agent is controlled for 2.5 to 5 hours. After the addition is completed, continue Keep warm for 0.5-2 hours, then cool to below 40°C, add sodium hydroxide aqueous solution to neutralize, control the product concentration to 20-50%, pH=6-8, and finally obtain light yellow transparent mucus;

The molar ratio of the macromonomer A to the small monomer B is 1:1 to 5;

The total amount of the oxidizing agent and reducing agent accounts for 0.2-5% of the total weight of the macromonomer A and small monomer B;

The amount of the chain transfer agent accounts for 0.05-0.25% of the total weight of the macromonomer A and the small monomer B.

The chain transfer agent is mercaptoethanol, mercaptoacetic acid, mercaptopropionic acid or mercaptosuccinic acid.

The oxidizing agent can be one or more of ammonium persulfate, potassium persulfate, sodium persulfate and hydrogen peroxide.

The reducing agent can be one or more of vitamin C, sodium sulfite, oxalic acid and glucose.

Polycarboxylate superplasticizer performance test according to GB8076-2008 and GB8077-2000

The molecular weight of the polycarboxylate water reducer is detected by aqueous gel chromatography, and the molecular weight is 5,000-200,000.

Compared with the prior art, the advantages and effects of the present invention: the macromonomer used in the present invention is isoprenyl polyoxyethylene ether, which not only has high activity, but also can carry out better copolymerization with acrylic small monomers, and synthesizes The water-reducing agent has a high water-reducing rate, good slump-retaining performance, and good adaptability to various cements, and the initiator used in the synthesis of its macromonomer is isoprenyl alcohol, the synthesis process is simple, and the price is low , easy to promote. The present invention adopts a redox initiation system and synthesizes a high-efficiency polyether polycarboxylate superplasticizer with water as a solvent. The production process is simple, the polymerization temperature is low, and the obtained polycarboxylate superplasticizer has excellent performance superior.

Detailed ways

Macromonomer A used for the copolymerization of the following examples of the present invention:

IB-500: Isoprenyl polyoxyethylene ether, the average molecular weight is 500;

IB-1000: Isoprenyl polyoxyethylene ether, the average molecular weight is 1000;

IB-1500: Isoprenyl polyoxyethylene ether, the average molecular weight is 1500;

IB-2000: Isoprenyl polyoxyethylene ether, the average molecular weight is 2000;

IB-2500: Isoprenyl polyoxyethylene ether, the average molecular weight is 2500;

IB-3000: Isoprenyl polyoxyethylene ether, the average molecular weight is 3000;

IB-5000: Isoprenyl polyoxyethylene propylene ether, the average molecular weight is 4000;

The small monomer B used in the following examples is acrylic acid or methacrylic acid.

Example 1

Add 150g of IB-500 and 120g of deionized water into a 1000ml four-neck flask equipped with mechanical stirring, temperature controller, and dripping device, and heat up while stirring and dissolving. When the temperature rises to 50°C, add 1.1g of 30% Hydrogen peroxide, when the temperature reaches 60°C, start to drop acrylic acid solution (22g acrylic acid dissolved in 10g deionized water) and a mixed solution of vitamin C and thioglycolic acid (0.5g vitamin C, 0.3g thioglycolic acid dissolved in 60g deionized water) ), the dropping time of the acrylic acid solution was controlled at 2.5 hours, the dropping time of the vitamin C solution was controlled at 3 hours, and the reaction temperature was controlled at 60±2°C. After the dropwise addition, continue to insulate for 0.5 hours, then cool to below 40°C, add aqueous sodium hydroxide solution (6.9g sodium hydroxide is dissolved in 71.1g deionized water) to neutralize, and obtain a concentration of 40%, pH=7.5 Pale yellow transparent mucus. After testing, the average molecular weight is 40000, and the density is 1.07g/ml.

Example 2

Add 155g of IB-1000 and 120g of deionized water into a 1000ml four-necked flask equipped with mechanical stirring, temperature controller and dripping device, and heat up while stirring and dissolving. When the temperature rises to 50°C, add 1.0g of 30% Hydrogen peroxide, when the temperature reaches 60°C, start to drop acrylic acid solution (16g acrylic acid dissolved in 10g deionized water) and a mixed solution of sodium sulfite and thioglycolic acid (0.4g sodium sulfite, 0.2g mercaptopropionic acid dissolved in 60g deionized water) , the dropping time of the acrylic acid solution was controlled at 2.5 hours, the dropping time of the vitamin C solution was controlled at 3 hours, and the reaction temperature was controlled at 60±2°C. After the dropwise addition, continue to insulate for 0.5 hours, then cool to below 40°C, add aqueous sodium hydroxide solution (5.0g sodium hydroxide is dissolved in 68.6g deionized water) to neutralize, and obtain a concentration of 40%, pH=7.5 Pale yellow transparent mucus. After testing, the average molecular weight is 43000, and the density is 1.07g/ml.

Example 3

Add 156g of IB-1500 and 120g of deionized water into a 1000ml four-necked flask equipped with mechanical stirring, temperature controller, and dripping device, and heat up while stirring and dissolving. When the temperature rises to 50°C, add 1.1g of 30% Hydrogen peroxide, when the temperature reaches 60°C, start to drop methacrylic acid solution (17g methacrylic acid dissolved in 10g deionized water) and a mixed solution of vitamin C and thioglycolic acid (0.52g vitamin C, 0.26g thioglycolic acid dissolved in 60g deionized water), the dropping time of the acrylic acid solution was controlled at 2.5 hours, the dropping time of the vitamin C solution was controlled at 3 hours, and the reaction temperature was controlled at 60±2°C. After the dropwise addition, continue to insulate for 0.5 hours, then cool to below 40°C, add aqueous sodium hydroxide solution (5.3g sodium hydroxide is dissolved in 71.9g deionized water) to neutralize, and obtain a concentration of 40%, pH=7.5 Pale yellow transparent mucus. After testing, the average molecular weight is 44000, and the density is 1.07g/ml.

Example 4

Add 165g of IB-2000 and 120g of deionized water into a 1000ml four-necked flask equipped with mechanical stirring, temperature controller and dripping device, and heat up while stirring and dissolving. When the temperature rises to 50°C, add 1.3g of 30% Hydrogen peroxide, when the temperature reaches 60°C, start to drop acrylic acid solution (16.5g acrylic acid dissolved in 10g deionized water) and a mixed solution of vitamin C and thioglycolic acid (0.48g vitamin C, 0.18g mercaptopropionic acid dissolved in 60g deionized water) deionized water), the dropping time of the acrylic acid solution was controlled at 2.5 hours, the dropping time of the vitamin C solution was controlled at 3 hours, and the reaction temperature was controlled at 60±2°C. After the dropwise addition, continue to insulate for 0.5 hours, then cool to below 40°C, add aqueous sodium hydroxide solution (5.2g sodium hydroxide is dissolved in 84.2g deionized water) to neutralize, and obtain a concentration of 40%, pH=7.5 Pale yellow transparent mucus. After testing, the average molecular weight is 46000, and the density is 1.07g/ml.

Example 5

Add 178g of IB-2500 and 120g of deionized water into a 1000ml four-neck flask equipped with mechanical stirring, temperature controller and dripping device, and heat up while stirring and dissolving. When the temperature rises to 50°C, add 1.2g of 30% Hydrogen peroxide, when the temperature reaches 60°C, start to drop acrylic acid solution (16.7g acrylic acid dissolved in 10g deionized water) and a mixed solution of sodium sulfite and thioglycolic acid (0.53g sodium sulfite, 0.27g thioglycolic acid dissolved in 60g deionized water) , the dropping time of the acrylic acid solution was controlled at 2.5 hours, the dropping time of the vitamin C solution was controlled at 3 hours, and the reaction temperature was controlled at 60±2°C. After the dropwise addition, continue to insulate for 0.5 hours, then cool to below 40°C, add aqueous sodium hydroxide solution (5.2g sodium hydroxide is dissolved in 104.3g deionized water) to neutralize, and obtain a concentration of 40%, pH=7.5 Pale yellow transparent mucus. After testing, the average molecular weight is 49000, and the density is 1.07g/ml.

Example 6

Add 187g of IB-3000 and 120g of deionized water into a 1000ml four-neck flask equipped with mechanical stirring, temperature controller, and dripping device, and heat up while stirring and dissolving. When the temperature rises to 50°C, add 1.3g of 30% Hydrogen peroxide, when the temperature reaches 60°C, start to drop acrylic acid solution (21g acrylic acid dissolved in 10g deionized water) and a mixed solution of vitamin C and thioglycolic acid (0.45g vitamin C, 0.13g mercaptopropionic acid dissolved in 60g deionized water) water), the dropping time of the acrylic acid solution was controlled at 2.5 hours, the dropping time of the vitamin C solution was controlled at 3 hours, and the reaction temperature was controlled at 60±2°C. After the dropwise addition, continue to insulate for 0.5 hours, then cool to below 40°C, add aqueous sodium hydroxide solution (6.6g sodium hydroxide is dissolved in 124.5g deionized water) to neutralize, and obtain a concentration of 40%, pH=7.5 Pale yellow transparent mucus. After testing, the average molecular weight is 81000, and the density is 1.07g/ml.

Example 7

Add 300g of IB-5000 and 120g of deionized water into a 1000ml four-neck flask equipped with mechanical stirring, temperature controller and dripping device, and heat up while stirring and dissolving. When the temperature rises to 50°C, add 1.2g of 30% Hydrogen peroxide, when the temperature reaches 60°C, start to drop methacrylic acid solution (18g methacrylic acid dissolved in 10g deionized water) and a mixed solution of vitamin C and thioglycolic acid (0.52g vitamin C, 0.32g thioglycolic acid dissolved in 60g deionized water), the dropping time of the acrylic acid solution was controlled at 2.5 hours, the dropping time of the vitamin C solution was controlled at 3 hours, and the reaction temperature was controlled at 60±2°C. After the dropwise addition, continue to insulate for 0.5 hours, then cool to below 40°C, add aqueous sodium hydroxide solution (5.7g sodium hydroxide is dissolved in 289.5g deionized water) to neutralize, and obtain a concentration of 40%, pH=7.5 Pale yellow transparent mucus. The tested average molecular weight is 53000 and the density is 1.07g/ml.

The evaluation method of the water reducer of the present invention is evaluated according to the GB8076-2008 standard, and the results are shown in Table 1 and Table 2.

Table 1 Net pulp fluidity data

Example Dosage (%) Mobility/mm 30min fluidity/mm 60min fluidity/mm 1 0.30 250 245 255 2 0.25 255 250 260 3 0.25 265 265 270 4 0.20 270 266 265 5 0.15 275 270 266 6 0.15 280 275 275 7 0.15 270 265 265

It can be seen from Table 1 that the polycarboxylate water reducer of the present invention has better dispersibility and dispersion retention for cement than the traditional polyether-based polycarboxylate water reducer.

Table 2 Concrete slump data

Example Dosage (%) Initial slump/mm 30min slump/mm 60min slump/mm 1 0.55 180 180 176 2 0.50 183 180 175 3 0.55 186 185 180 4 0.55 195 190 190 5 0.45 200 196 193 6 0.40 215 200 195 7 0.40 205 202 200

It can be seen from Table 2 that the polycarboxylate water reducer of the present invention has better dispersibility and slump retention for concrete than the traditional polyether-based polycarboxylate water reducer.

Claims (2)

1. An isoprenyl polyether polycarboxylate water reducer, which is isoprenyl polyoxyethylene ether or isoprenyl polyoxyethylene propylene ether (A) and unsaturated carboxylic acid Or the polymkeric substance of derivative (B) thereof, represent macromonomer A with formula (1), represent small monomer B with formula (2): Among them: R ₁ -hydrogen atom or an alkyl group with 1 to 5 C atoms m-the number of repeating units is 5 to 200 n-the number of repeating units is 0 to 100,

Where: R ₂ -hydrogen atom or methyl R ₃ -hydroxyl. 2. The synthetic method of isoprenyl polyether polycarboxylate water reducer as claimed in claim 1, is characterized in that, step comprises: macromonomer A is dissolved in deionized water, heats up while stirring , when the temperature rises to 30-50°C, add an oxidizing agent, and when the temperature reaches 60-80°C, start to add the small monomer B aqueous solution and the mixed aqueous solution of the reducing agent and the chain transfer agent at the same time, and the small monomer B aqueous solution dripping time Control it within 2-4 hours, and control the dropwise addition time of the mixed aqueous solution of reducing agent and chain transfer agent within 2.5-5 hours. After the dropwise addition, continue to keep warm for 0.5-2 hours, then cool to below 40°C, and add sodium hydroxide aqueous solution Neutralize, control the product concentration to 20-50%, pH = 6-8, and finally obtain light yellow transparent mucus; The molar ratio of the macromonomer A to the small monomer B is 1:1 to 5; The total amount of the oxidizing agent and reducing agent accounts for 0.2-5% of the total weight of the macromonomer A and small monomer B; The amount of the chain transfer agent accounts for 0.05% to 0.25% of the total weight of the macromonomer A and the small monomer B; The chain transfer agent is mercaptoethanol, mercaptoacetic acid, mercaptopropionic acid or mercaptosuccinic acid; The oxidizing agent is one or more of ammonium persulfate, potassium persulfate, sodium persulfate and hydrogen peroxide; The reducing agent is one or more of vitamin C, sodium sulfite, oxalic acid and glucose.