Preparation method of phosphate-based polyether type viscosity reducer and phosphate-based polyether type viscosity reducer

Abstract

The present invention provides a preparation method of a phosphate-based polyether type viscosity reducer and a phosphate-based polyether type viscosity reducer, and the preparation method of the phosphate-based polyether type viscosity reducer comprises the following steps: a hypochlorite aqueous solution is mixed with a polyether macromonomer aqueous solution, phosphorous acid is added, and heating is performed. After the reaction is completed, the phosphate-based polyether type viscosity reducer is obtained. The phosphate-based polyether type viscosity reducer preparation method of the present invention is subjected to an addition reaction of a polyether macromonomer, and a terminal chlorinated polyether is obtained with high efficiency, and then a phosphorylation reaction is performed, and a phosphorus atom of phosphorous acid with a lone electron pair reacts with an electrophilic chlorinated carbon atom, and trivalent phosphorus is changed to pentavalent phosphorus, and a carbon-phosphorus bond is directly formed, and the reaction efficiency is relatively high. In addition, the carbon-phosphorus bond has hydrolysis resistance, and compared with the phosphoric acid group formed by esterification, the chemical property is more stable. Compared with the Mannich reaction, it has the advantage of simple process.

Description

Technical Field

[0001] The invention relates to the field of building materials, in particular to a method for preparing a phosphate-based polyether type viscosity reducer. The invention also relates to the phosphate-based polyether type viscosity reducer prepared by the method. Background Art

[0002] With the continuous development of contemporary civil engineering and construction industry, more and more challenging engineering goals have been achieved, among which the application of high-strength concrete has played an important role. At present, high-grade concrete is increasingly used in infrastructure construction at home and abroad. The primary way to achieve high strength is to reduce the water-binder ratio. Due to the reduction of the water-binder ratio, the aggregate is more densely packed, so it has higher strength. However, the low water-binder ratio brings about an increase in the viscosity of the concrete, which reduces the workability and workability of the concrete, making it more difficult to apply in engineering. At the same time, the high viscosity leads to slow discharge of bubbles, which is not conducive to improving the strength and durability of concrete.

[0003] Literature research shows that single-chain polyether molecules terminated with bisphosphonic acid groups can be adsorbed on the surface of calcium carbonate powder, improving the dispersibility of calcium carbonate particles. Rheometer tests have shown that single-chain polyether dispersants can significantly reduce the shear viscosity of lime slurry.

[0004] CN110734244A discloses a method for preparing a polyphosphonic acid-based single-chain polyethylene glycol. First, polyethylene glycol monomethyl ether is halogenated with dithionyl chloride, and then reacted with ethylene polyamine to prepare polyether polyamine. Next, the polyether polyamine is subjected to a Mannich reaction with formaldehyde and phosphorous acid to synthesize polyether polyphosphonic acid. This single-chain molecule has a good anti-slump effect, can reduce the amount of polycarboxylic acid water-reducing agent, and can also improve the workability and compressive strength of concrete.

[0005] In addition, CN111378114A and CN111377645A also use the Mannich reaction to prepare single-chain polyether phosphonic acid molecules, which also have the characteristics of resisting mud collapse and improving concrete fluidity and workability.

[0006] CN106008853A discloses a method for preparing a polycarboxylic acid water reducer containing a phosphate group and having an anti-mud collapse protection function by using an Arbuzov reaction. First, a vinyl monomer containing a haloalkyl group is copolymerized with acrylic acid and a polyether macromonomer to obtain a polycarboxylic acid macromolecule modified with a halo group, and then a phosphite is reacted with the halo group to obtain a polycarboxylic acid water reducer modified with a phosphonate. Due to the strong adsorption of the phosphonic acid group, the water reducer has the characteristics of a high water reduction rate. At the same time, the phosphonic acid group has anti-mud collapse protection performance. Compared with the Mannich reaction, the introduction of the phosphonic acid group by the Arbuzov reaction has the characteristics of a relatively simple process and low production cost.

[0007] CN108129625B discloses a technical route for introducing phosphonic acid groups by esterification reaction. Azeotropic distillation is used in the esterification reaction to remove the water generated by the reaction with the aid of a water-carrying agent, so the process is relatively complicated and the conditions are difficult to master. In addition, the phosphate group and carbon generated by esterification are easily hydrolyzed and have poor stability. Summary of the invention

[0008] The invention provides a phosphate-based polyether viscosity reducer to enable concrete to have excellent early strength and viscosity reduction effects.

[0009] A method for preparing a phosphate-based polyether type viscosity reducer comprises the following steps: mixing a hypochlorite aqueous solution with a polyether macromonomer aqueous solution for reaction, adding phosphorous acid, heating, and obtaining the phosphate-based polyether type viscosity reducer after the reaction is completed.

[0010] Furthermore, the polyether macromonomer includes at least one of allyl polyoxyethylene ether, methyl allyl alcohol polyoxyethylene ether, and isopentanol polyoxyethylene ether.

[0011] Furthermore, the molecular weight of the polyether macromonomer is 500-5000.

[0012] Furthermore, the effective chlorine content of the hypochlorite aqueous solution is 5-15%.

[0013] Furthermore, the mass ratio of the polyether macromonomer to water in the polyether macromonomer aqueous solution is greater than 1:2.

[0014] Furthermore, the heating temperature is 50-90 degrees Celsius.

[0015] The present invention also provides a phosphate-based polyether type viscosity reducer, which is prepared by the above method.

[0016] The preparation method of the phosphate-based polyether type viscosity reducer of the present invention is to subject a polyether macromonomer to an addition reaction, to obtain a terminal chlorinated polyether with high efficiency, and then to carry out a phosphorylation reaction, wherein the phosphorus atom of phosphorous acid with a lone electron pair reacts with an electrophilic chlorinated carbon atom, and trivalent phosphorus is converted into pentavalent phosphorus, and a carbon-phosphorus bond is directly formed, and the reaction efficiency is high. In addition, the carbon-phosphorus bond is resistant to hydrolysis, and has a more stable chemical property than the phosphoric acid group formed by esterification. Compared with the Mannich reaction, it has the advantage of a simple process. DETAILED DESCRIPTION

[0017] It should be noted that, in the absence of conflict, the embodiments of the present invention and the features in the embodiments may be combined with each other.

[0018] The experimental methods in the following examples are conventional methods unless otherwise specified. The experimental materials used in the following examples are purchased from conventional biochemical reagent stores unless otherwise specified. In addition, except for special instructions in this example, the terms and processes involved in this example are understood according to the general knowledge and conventional methods in the prior art.

[0019] A method for preparing a phosphate-based polyether viscosity reducer, the method specifically comprising the following steps: mixing an aqueous hypochlorite solution with an aqueous polyether macromonomer solution to allow an unsaturated double bond of the polyether macromonomer to undergo an addition reaction with hypochlorite, then adding phosphorous acid, heating to 50-90 degrees Celsius, and obtaining the phosphate-based polyether viscosity reducer after the reaction is completed.

[0020] For the dosage of the above raw materials, when the unsaturated double bond content of the polyether macromonomer is known, the dosage of the chlorate solution can be calculated according to the chlorine content of the hypochlorite solution, so that the molar ratio of the unsaturated double bond to the hypochlorite is about 1:1. In addition, in order to increase the reaction rate of the addition chlorination group, the hypochlorite solution is added at 1.02 times the calculated equivalent. After the hypochlorite aqueous solution and the polyether macromonomer aqueous solution are mixed, 0.02 equivalents of the reducing agent sodium sulfite can be used to neutralize the remaining active chlorine, and the chlorine test paper is used for monitoring to ensure that there is no residual chlorine in the reaction system to prevent the excess hypochlorite in the hypochlorite aqueous solution from oxidizing the subsequently added phosphorous acid. Of course, the dosage of the hypochlorite solution can also be added in 1 times the equivalent number to balance the reaction ratio. Therefore, whether to add a reducing agent depends on the dosage of the hypochlorite solution, and the present invention does not limit this.

[0021] The preparation method of the present invention is to transform the alkenyl group of the polyether macromonomer, utilize the addition reaction of unsaturated double bond and hypochlorite, convert the alkenyl group into chloro group, simply and efficiently prepare the polyether containing halide group, adopt hypochlorous acid to add chloro group reaction, have the characteristics of good economy, and do not need auxiliary catalyst, and have few by-products. Then the polyether containing chloro group is further reacted with phosphorous acid, and the phosphorus atom of phosphorous acid with lone electron pair reacts with electrophilic chlorinated carbon atom, so that trivalent phosphorus becomes pentavalent phosphorus, phosphoric acid replaces chlorine, directly forms carbon-phosphorus bond, has high reaction efficiency, carbon-phosphorus bond has hydrolysis resistance, and compared with the phosphoric acid group formed by esterification, chemical property is more stable. Compared with Mannich reaction, it has the advantage of simple process.

[0022] The polyether macromonomer preferably includes at least one of allyl polyoxyethylene ether (APEG), methyl allyl alcohol polyoxyethylene ether (HPEG), and isopentanol polyoxyethylene ether (TPEG). The molecular weight of the polyether macromonomer is preferably 500-5000. The effective chlorine content of the hypochlorite solution is 5-15%. The mass ratio of the polyether macromonomer to water in the polyether macromonomer aqueous solution is greater than 1:2, so that it can be fully dissolved and the concentration is high. If necessary, it can be heated to increase the solubility, preferably 3:2.

[0023] The present invention also provides a phosphate-based polyether type viscosity reducer, which is prepared by the above method.

[0024] The phosphate polyether viscosity reducer of the present invention is a single-chain type, and the adsorption group is composed of a phosphate group, has a strong adsorption capacity, a small molecular weight, and a fast moving speed in the cement slurry solution. Especially in the case of a low water-cement ratio, very little free water is easily wrapped by the cementitious material. The addition of this dispersant can quickly disperse the cementitious material particles and reduce the probability of their agglomeration. The phosphate polyether viscosity reducer and the water reducer mother liquor are used in combination. Initially, the viscosity reducer quickly disperses the cement particles at a micro-distance, and then the water reducer mother liquor uses the long side chain and strong steric hindrance to continuously disperse the cement particles, with a high water reduction rate, better effects of reducing viscosity and enhancing workability, and better uniformity and mixing properties of the concrete, and lower plastic viscosity.

[0025] All of the above raw materials can be purchased from the market.

[0026] As follows, the technical solution of the present invention is described in detail through specific embodiments:

[0027] Example 1

[0028] Mix 18g of polyether macromonomer APEG 1200 and 12g of water at 60 degrees. Add about 6ml of sodium hypochlorite solution containing 14% chlorine at room temperature. After 30 minutes, add sodium sulfite solution dropwise to the mixture until the chlorine test paper just fails to detect residual chlorine. Add 1.23g of phosphorous acid to the mixture and heat to 70 degrees Celsius for 3 hours.

[0029] Example 2

[0030] Mix 18g of polyether macromonomer HPEG 2000 and 12g of water at 65 degrees. Add about 3.6ml of sodium hypochlorite solution containing 14% chlorine at room temperature, react for 30 minutes, and then add sodium sulfite solution dropwise to the mixture until the chlorine test paper just fails to detect residual chlorine. Add 0.74g of phosphorous acid to the mixture and heat to 60°C for 2 hours.

[0031] Example 3

[0032] Mix 12g of polyether macromonomer TPEG 2400 and 8g of water at 50 degrees. Add about 2ml of sodium hypochlorite solution containing 14% chlorine at room temperature, react for 30 minutes, and then add sodium sulfite solution to the mixture until the chlorine test paper just fails to detect residual chlorine. Add 0.41g of phosphorous acid to the mixed solution and heat to 80°C for 4 hours.

[0033] Comparative Example 1

[0034] This comparative example adopts Example 1 of the anti-mud and collapse-preserving phosphate-based polycarboxylate water-reducing agent of patent CN110734244A.

[0035] Comparative Example 2

[0036] This comparative example adopts sample 1 of the slow-setting small-molecule phosphate-based superplasticizer of patent CN108129625B.

[0037] The following is the performance test of the present invention:

[0038] Taking the commercially available water reducing agent product: GK-3000 of Shijiazhuang Changan Yucai Building Materials Co., Ltd. as the benchmark, the embodiments and comparative examples with 10% of the GK-3000 water reducing agent content were tested, and the cement concrete working performance test was carried out according to JGJ / T283-2012 "Technical Application Specifications for Self-compacting Concrete", wherein the water-binder ratio was 0.27 and the initial expansion of the concrete was controlled to 650±10mm. The concrete mix ratio is shown in Table 1, and the concrete performance test results are shown in Table 2.

[0039] Table 1 Concrete mix ratio

[0040] W C SF F S G5-10mm G10-20 150 470 40 40 832 658 285

[0041] Table 2 Concrete test results

[0042]

[0043]

[0044] It can be seen from the concrete evaluation data that when the concrete expansion is close, compared with the water reducer without the viscosity reducer of the present invention, the water reducer containing 10% of the embodiment is added to the self-compacting concrete, and the pouring time is significantly faster, the V-shaped groove does not have a stone-blocking phenomenon relative to the benchmark water reducer, and the flow rate is significantly reduced. This shows that after adding the phosphate-based polyether viscosity reducer, the uniformity and mixing properties of the concrete are better, the plastic viscosity is lower, and the 3d, 7d and 28d strengths of the concrete do not decrease. Therefore, the phosphate-based polyether viscosity reducer of the present invention has excellent effects of reducing viscosity and enhancing workability.

[0045] The preferred embodiments of the present invention are described in detail above. However, the present invention is not limited to the specific details in the above embodiments. Within the technical concept of the present invention, a variety of simple modifications can be made to the technical solution of the present invention, and these simple modifications all belong to the protection scope of the present invention.

[0046] It should also be noted that the various specific technical features described in the above specific embodiments can be combined in any suitable manner without contradiction. In order to avoid unnecessary repetition, the present invention will not further describe various possible combinations.

Claims

1. A method for preparing a phosphate-based polyether viscosity reducer, characterized in that: The preparation method of the phosphate polyether type viscosity reducer comprises the following steps: The hypochlorite aqueous solution and the polyether macromonomer aqueous solution are mixed for reaction, phosphorous acid is added, and heating is performed. After the reaction is completed, the phosphate-based polyether viscosity reducer is obtained; The polyether macromonomer includes at least one of allyl polyoxyethylene ether, methyl allyl alcohol polyoxyethylene ether and isopentanol polyoxyethylene ether.

2. The method for preparing the phosphate-based polyether viscosity reducer according to claim 1, characterized in that: The molecular weight of the polyether macromonomer is 500-5000.

3. The method for preparing the phosphate-based polyether viscosity reducer according to claim 1, characterized in that: The effective chlorine content of the hypochlorite aqueous solution is 5-15%.

4. The method for preparing the phosphate-based polyether viscosity reducer according to claim 1, characterized in that: The mass ratio of polyether macromonomer to water in the polyether macromonomer aqueous solution is greater than 1:

2.

5. The method for preparing the phosphate-based polyether viscosity reducer according to any one of claims 1 to 4, characterized in that: The heating temperature is 50-90 degrees Celsius.

6. A phosphate-based polyether viscosity reducer, characterized in that: The phosphate-based polyether viscosity reducer is prepared by the preparation method of the phosphate-based polyether viscosity reducer according to any one of claims 1 to 5.

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