阅读说明：本技术 一种稳定泵送混凝土用聚合物及其制备方法 (Polymer for stabilizing pumped concrete and preparation method thereof ) 是由 李相国 傅秋艳 柯凯 吕阳 蹇守卫 许金生 于 2021-01-29 设计创作，主要内容包括：本发明公开了一种稳定泵送混凝土用聚合物及其制备方法,所述聚合物主要由以下几种材料制备而成：醇类单体20-25份、环氧化物380-450份、磺酸类单体13-17份、催化剂a0.13-0.20份、催化剂b 0.10-0.14份、酸类小单体30-35份、氧化剂1.1-3.0份、还原剂3.3-5.5份、链转移剂1.0-2.2份、中和剂4.6-8.5份,其余为去离子水。通过合成400-600左右分子质量的不饱和中间体,进一步与一定摩尔质量比的酸类小单体在恒温条件下,经过引发剂与链转移剂进行调控,制备一种分子量分布范围窄的高缓凝性聚合物。所述高缓凝性聚合物,减水能力强,并且在多种情况下都具有良好的分散性,制备方法简单,值得推广应用。(The invention discloses a polymer for stabilizing pumped concrete and a preparation method thereof, wherein the polymer is mainly prepared from the following materials: 20-25 parts of alcohol monomer, 450 parts of epoxide 380-one, 13-17 parts of sulfonic acid monomer, 0.13-0.20 part of catalyst a, 0.10-0.14 part of catalyst b, 30-35 parts of acid small monomer, 1.1-3.0 parts of oxidant, 3.3-5.5 parts of reducing agent, 1.0-2.2 parts of chain transfer agent, 4.6-8.5 parts of neutralizing agent and the balance of deionized water. The unsaturated intermediate with molecular mass of about 400-600 is synthesized and further regulated and controlled with acid small monomer with a certain molar mass ratio through an initiator and a chain transfer agent under the constant temperature condition to prepare the high-retarding polymer with narrow molecular weight distribution range. The high-retarding polymer has strong water reducing capacity, good dispersibility under various conditions, simple preparation method and worth of popularization and application.)

1. The preparation method of the polymer for stabilizing the pump concrete is characterized by sequentially comprising the following operation steps of:

the method comprises the following steps: preparation of unsaturated intermediates

Adding 20-25 parts of alcohol monomer as an initiator and 0.13-0.20 part of catalyst a into a high-pressure reaction kettle with a stirring device and a temperature control device, then carrying out nitrogen replacement for 4 times under stirring, starting heating, raising the temperature to about 110-150 ℃, then slowly introducing 90-120 parts of epoxide into the reactor for induction reaction, gradually raising the temperature to about 110-125 ℃ in the induction process, maintaining the constant temperature state, maintaining the pressure at 0.15-0.60MPaG, keeping the temperature for about 2-2.5 hours, adding 0.10-0.14 part of catalyst b again when the pressure of the reactor is not reduced, slowly introducing 270-340 parts of epoxide into the container for induction reaction with 13-17 parts of sulfonic acid monomer, maintaining the temperature at 150 ℃ under 125-, vacuumizing and degassing, and discharging to obtain an unsaturated intermediate with the molecular weight of about 400-;

step two: polymer preparation

Adding 380-450 parts of the unsaturated intermediate prepared in the first step and 200 parts of deionized water into a four-neck flask as a bottom material, adding 120 parts of deionized water into 30-35 parts of acid small monomer as a material A, adding 1.0-2.2 parts of chain transfer agent, 3.3-5.5 parts of reducing agent and 50 parts of deionized water to prepare a material B, adding 60 parts of deionized water into 1.1-3.0 parts of oxidant to prepare a material C, heating a water bath to 35-45 ℃, placing the four-neck flask filled with the bottom material into the water bath, adding 1/3C at a constant speed, dropwise adding the material A and the material B for 3 hours, dropwise adding the material B for 3 hours and 10 minutes, adjusting the pH in the reaction kettle to 4-5 by using dilute sulfuric acid after the reaction is carried out for 1.2 hours, then adding the rest material C at a time, adding alkali for neutralization, supplementing water to the required solid content after the material A and the material B are dropwise added, naturally cooling to the room temperature after 1 hour, and obtaining a polymer solution, namely the polymer for the stable pumping concrete.

2. The method of claim 1 for preparing a polymer for stabilizing pumped concrete, wherein the polymer comprises: the alcohol monomer is poly 1, 2 propylene glycol, and the epoxide is propylene oxide.

3. The method of claim 1 for preparing a polymer for stabilizing pumped concrete, wherein the polymer comprises: the sulfonic acid monomer is 2-propane sodium sulfonate.

4. The method of claim 1 for preparing a polymer for stabilizing pumped concrete, wherein the polymer comprises: the catalyst a is lithium aluminum hydride, and the catalyst b is any one or a combination of sodium hydroxide, potassium hydroxide and boron trifluoride vinyl ether.

5. The method of claim 1 for preparing a polymer for stabilizing pumped concrete, wherein the polymer comprises: the acid small monomer is any one or combination of acrylic acid, fumaric acid, maleic anhydride, acrylic acid-2-ethylhexyl ester and methacryloyloxyethyl phthalic monoester.

6. The method of claim 1 for preparing a polymer for stabilizing pumped concrete, wherein the polymer comprises: the oxidant is any one or combination of azodiisobutyronitrile, 2' -azobis- (2, 4-dimethylvaleronitrile), benzoyl peroxide and ammonium persulfate.

7. The method of claim 1 for preparing a polymer for stabilizing pumped concrete, wherein the polymer comprises: the reducing agent is any one or combination of sodium hydrosulfite, ascorbic acid, sodium formaldehyde sulfoxylate, maltodextrin, sodium hydrosulfite and sodium metabisulfite.

8. The method of claim 1 for preparing a polymer for stabilizing pumped concrete, wherein the polymer comprises: the chain transfer agent is any one or combination of sodium hypophosphite, mercaptopropionic acid, thioglycolic acid and sodium methallyl sulfonate.

9. The method of claim 1 for preparing a polymer for stabilizing pumped concrete, wherein the polymer comprises: the neutralizing agent is any one or a combination of several of sodium hydroxide solution, potassium hydroxide, sodium carbonate, sodium bicarbonate, potassium carbonate, sodium methoxide, sodium ethoxide, ethanolamine, diethanolamine, triethanolamine and triisopropanolamine.

10. A polymer for stabilizing pumped concrete, characterized by: prepared by the preparation method of any of claims 1 to 9.

Technical Field

The invention belongs to the field of additives, relates to a synthesis technology of a polycarboxylic acid polymer, and provides a polymer for stabilizing pump concrete and a preparation method thereof.

Background

The quality of the concrete is the key for ensuring the quality of construction engineering, and from the perspective of engineering practice, the concrete has excellent mixture performance, mechanical property, durability and the like, but with increasingly deficient resource materials such as high-quality sand stones and the like, the available high-quality raw materials are less and less. With the market change and the aggravation of industry competition, the application of inferior materials is in an increasing trend, and how to use inferior raw materials to mix high-performance and high-quality concrete is the central importance of the research on concrete admixtures. The polycarboxylic acid polymer is a cement polymer widely used in the concrete industry, and can reduce the use amount of water in the concrete mixing process and improve various properties of concrete. Meanwhile, the strength of concrete depends on the ratio of water to cement (water cement ratio), and the smaller the water cement ratio, the higher the strength of the concrete material. The polycarboxylic acid polymer can also remarkably improve the strength of concrete. In a sense, the main gap in concrete technology in various countries at present is the level of the admixture, especially the development level of the high-retarding concrete polymer. Therefore, the development of highly adaptable polycarboxylic acid polymers is imminent.

The invention provides an antifreezing polycarboxylic acid composite pumping slump retaining agent, which comprises, by weight, 8-12% of a polycarboxylic acid efficient slump retaining agent, 0.5-1% of a plasticizing component, 0.05-0.1% of an air entraining agent, 0.8-1.5% of triethanolamine, 8-15% of an inorganic early strength component, 8-15% of an organic antifreezing component, and the balance of water. The anti-freezing polycarboxylic acid composite pumping slump retaining agent has the advantages that various organic and inorganic components are combined with the polycarboxylic acid slump retaining agent mother solution, the effect is good, the product is uniform and stable, and the phenomenon of layering is avoided.

Patent CN201710971195.8 discloses a composite type retarding slump retaining agent for long-distance pumped concrete, which relates to the technical field of concrete additives and is prepared from the following raw materials in parts by weight: 35-45 parts of naphthalene slump retaining agent, 10-5 parts of soil-grade polyglutamic acid, 5-10 parts of nano rubber powder, 5-10 parts of superfine wollastonite powder, 1-5 parts of cross-linked povidone, 1-5 parts of poly-dipentaerythritol hexa-diethyl acrylate, 1-5 parts of trimethylolpropane triglycidyl ether, 0.5-2 parts of sodium gluconate and 0.5-2 parts of diphenylphosphinic chloride. The retarding slump retaining agent prepared by the invention has good water reducing effect, good water retention, small bleeding rate and low gas content; and the hydration process of cement can be effectively delayed, and the setting time is adjusted, so that the initial setting time is about 8 hours, and the final setting time is about 10 hours.

Patent CN202010226607.7 discloses a super slow-release polycarboxylic acid pumping agent, which is composed of the following components in percentage by weight: 60% -80% of high-efficiency slump retaining agent; 0.5% -1% of fullerene suspension subjected to surface modification; 6% -8% of aliphatic compounds; 1% -5% of sodium gluconate; 1% -5% of carboxylic acid graft copolymer; 0.1-0.5% of cellulose and the balance of water, firstly adding water into a stirrer, and then adding the fullerene suspension subjected to surface modification; high-efficiency slump retaining agent; an aliphatic compound; sodium gluconate; carboxylic acid-based graft copolymers; and sequentially adding the cellulose into the mixer, and stirring for 7-10 hours. The ultra-slow release type polycarboxylic acid pumping agent can improve the impermeability, frost resistance and durability of concrete, can reduce the slump loss of the concrete, is suitable for long-distance transportation and pumping construction, has wide application range, is convenient to purchase raw materials, has lower cost and has obvious economic value.

Different from the patents, the invention uses the poly-1, 2-propylene glycol head to self-prepare a polyether macromonomer to carry out polymerization reaction with acrylic acid, carries out reasonable modification according to the performance of the water reducing agent, prepares the concrete admixture for the slow-setting pumping with short and moderate main chain length and proper acid-ether ratio by a simple free radical polymerization method, not only has adsorption slow-setting function, but also has excellent lubricating and air-entraining effects, and is very suitable for the concrete for the long-distance transportation high-rise pumping.

Disclosure of Invention

Aiming at the defects in the prior art, the invention aims to provide the high-efficiency polymer for concrete, and the polymer prepared by the scheme has the advantages of simple preparation process, excellent product performance, good stability, wide adaptability and environmental protection.

The invention concept of the invention is as follows: the high-performance polycarboxylic acid polymer with high retardation prepared by the method has the advantages of maintaining good dispersion on cement under different cement conditions, and has the advantages of simple process, controllable process, energy conservation and environmental protection, realizes cationization substitution of the conventional polyether side chain, and has better application potential and development prospect.

In order to solve the above problems, the technical scheme of the invention is as follows:

the preparation method of the polymer for stabilizing the pump concrete is characterized by sequentially comprising the following operation steps of:

the method comprises the following steps: preparation of unsaturated intermediates

Adding 20-25 parts of alcohol monomer as an initiator and 0.13-0.20 part of catalyst a into a high-pressure reaction kettle with a stirring device and a temperature control device, then carrying out nitrogen replacement for 4 times under stirring, starting heating, raising the temperature to about 110-150 ℃, then slowly introducing 90-120 parts of epoxide into the reactor for induction reaction, gradually raising the temperature to about 110-125 ℃ in the induction process, maintaining the constant temperature state, maintaining the pressure at 0.15-0.60MPaG, keeping the temperature for about 2-2.5 hours, adding 0.10-0.14 part of catalyst b again when the pressure of the reactor is not reduced, slowly introducing 270-340 parts of epoxide into the container for induction reaction with 13-17 parts of sulfonic acid monomer, maintaining the temperature at 150 ℃ under 125-, vacuumizing and degassing, and discharging to obtain an unsaturated intermediate with the molecular weight of about 400-;

step two: polymer preparation

Adding 380-450 parts of the unsaturated intermediate prepared in the first step and 200 parts of deionized water into a four-neck flask as a bottom material, adding 120 parts of deionized water into 30-35 parts of acid small monomer as a material A, adding 1.0-2.2 parts of chain transfer agent, 3.3-5.5 parts of reducing agent and 50 parts of deionized water to prepare a material B, adding 60 parts of deionized water into 1.1-3.0 parts of oxidant to prepare a material C, heating a water bath to 35-45 ℃, placing the four-neck flask filled with the bottom material into the water bath, adding 1/3C at a constant speed, dropwise adding the material A and the material B for 3 hours, dropwise adding the material B for 3 hours and 10 minutes, adjusting the pH in the reaction kettle to 4-5 by using dilute sulfuric acid after the reaction is carried out for 1.2 hours, then adding the rest material C at a time, adding alkali for neutralization, supplementing water to the required solid content after the material A and the material B are dropwise added, naturally cooling to the room temperature after 1 hour, and obtaining a polymer solution, namely the polymer for the stable pumping concrete.

Further, the solid content of the polymer for the stable pump concrete is 30-45%, and the optimal solid content is 40%;

furthermore, the total mass part of the raw materials for preparing the polymer for the stable pump concrete is 1000 parts, namely 1 part, namely 1 g.

Preferably, the alcohol monomer is poly-1, 2-propylene glycol.

Preferably, the epoxide is propylene oxide.

Preferably, the sulfonic acid monomer is sodium 2-propane sulfonate.

Preferably, the molar ratio of the alcohol monomer to epoxide charge is 1 (15.1-18.3), most preferably 1: 17.

preferably, the catalyst a is lithium aluminum hydride, and the dosage is 0.1-0.75 per mill, and most preferably 0.45 per mill based on the total mass fraction of the alcohol monomer and the epoxide.

Preferably, the catalyst b is any one or combination of sodium hydroxide, potassium hydroxide and boron trifluoride vinyl ether, and most preferably the mass ratio of potassium hydroxide to boron trifluoride vinyl ether is 1:3.

Preferably, the acid small monomer is any one or combination of acrylic acid, fumaric acid, maleic anhydride, acrylic acid-2-ethylhexyl ester and methacryloyloxyethyl phthalic monoester, and most preferably the mass ratio of acrylic acid to methacryloyloxyethyl phthalic monoester is 1: 2.3.

Preferably, the molar ratio of the acid small monomer to the unsaturated intermediate is 1 (3.1-5.5), and most preferably 1: 4.2.

Preferably, the oxidant is any one or combination of 2, 2' -azobis- (2, 4-dimethylvaleronitrile), Benzoyl Peroxide (BPO) and Ammonium Persulfate (APS), and most preferably Ammonium Persulfate (APS).

Preferably, the amount of the oxidizing agent is 2.1% to 2.7%, most preferably 2.32%, based on the acid small monomer.

Preferably, the reducing agent is any one or combination of sodium hydrosulfite, ascorbic acid, sodium formaldehyde sulfoxylate, maltodextrin, sodium hydrosulfite and sodium metabisulfite, and most preferably the ascorbic acid and the sodium hydrosulfite in a mass ratio of 1: 3.6.

Preferably, the chain transfer agent is any one or combination of sodium hypophosphite, mercaptopropionic acid, thioglycolic acid and sodium methallyl sulfonate, and the mass ratio of the mercaptopropionic acid to the thioglycolic acid is 1: 4.2.

Preferably, the neutralizer is any one or combination of several of sodium hydroxide solution with 30% solubility, potassium hydroxide, sodium carbonate, sodium bicarbonate, potassium carbonate, sodium methoxide, sodium ethoxide, ethanolamine, diethanolamine, triethanolamine and triisopropanolamine, and most preferably the sodium methoxide and sodium ethoxide in a mass ratio of 1:3.

The polymer for the stable pump concrete is prepared from the following raw materials in parts by weight:

alcohol monomer: 20-25 parts;

epoxide: 380-450 parts;

sulfonic acid monomer: 13-17 parts;

catalyst a: 0.13-0.20 part;

catalyst b: 0.10-0.14 part;

acid small monomer: 30-35 parts;

oxidizing agent: 1.1-3.0 parts;

reducing agent: 3.3-5.5 parts;

chain transfer agent: 1.0-2.2 parts;

neutralizing agent: 4.6-8.5 parts;

the balance of deionized water, the total mass is 1000 parts, and the solid content is about 40%.

Compared with the prior art, the invention has the advantages and beneficial effects that:

1. has good salt resistance and can keep good dispersibility under various conditions.

2. The synthesis process is simple, the controllability is good, the polymerization rate change in the whole reaction process is controlled by adjusting factors such as temperature, pressure, PH and the like in the reaction process, the molecular structure and the functional design are carried out, and the polymer with ideal performance is prepared.

Drawings

FIG. 1 SEM image of 1d concrete sample with BS-2017-A concrete addition.

FIG. 2 SEM image of 1d concrete sample with addition of polymer prepared in example 1.

Detailed Description

The applicant will make further detailed descriptions of technical solutions and advantages of the present invention with reference to specific examples, but it should be understood that the following examples should not be construed as limiting the scope of the claims of the present application in any way.

Example 1

The total mass parts of the raw materials for preparing the polymer for the stable pump concrete are 1000 parts, each mass part in the embodiment is 1g, and the mass parts of the raw materials are as follows:

alcohol monomer: 25 parts of poly (1, 2-propylene glycol);

epoxide: 380 parts of propylene oxide;

sulfonic acid monomer: 14 parts of 2-propane sodium sulfonate;

catalyst a: 0.13 part of lithium aluminum hydride;

catalyst b: 0.11 part of potassium hydroxide;

acid small monomer: 35 parts of acrylic acid;

oxidizing agent: 2.2 parts of ammonium persulfate;

reducing agent: 4.5 parts of ascorbic acid;

chain transfer agent: 1.2 parts of mercaptopropionic acid and mercaptoacetic acid in a mass ratio of 1: 2;

neutralizing agent: 5.4 parts of sodium hydroxide;

the balance of deionized water.

The preparation method comprises the following specific operation steps:

the method comprises the following steps: preparation of unsaturated intermediates

Adding 25 parts of poly (1, 2-propylene glycol) into a high-pressure reaction kettle with a stirring device and a temperature control device, adding 0.13 part of lithium aluminum hydride, stirring, performing nitrogen replacement for 4 times, starting heating, raising the temperature to about 120 ℃, then slowly introducing 90 parts of propylene oxide into the reactor for an induction reaction, gradually raising the temperature to about 110-150 ℃ in the induction process, maintaining the constant temperature at 130 ℃, maintaining the pressure at 0.25MPaG relatively constant, and keeping the temperature for about 2 hours, when the pressure of the reactor does not decrease (the propylene oxide is gaseous at the temperature, the pressure of the reactor does not decrease, indicating that the propylene oxide basically reacts completely), adding 0.11 part of potassium hydroxide again, slowly introducing 290 parts of propylene oxide into the container for an induction reaction with 14 parts of sodium 2-propanesulfonate, maintaining the temperature at 135 ℃, when the pressure of the reactor does not decrease again, reducing the temperature to 110 ℃, vacuumizing and degassing, and discharging to obtain an unsaturated intermediate with the molecular weight of about 400-.

Step two: polymer preparation

Adding the unsaturated intermediate prepared in the step one and 220 parts of deionized water into a four-neck flask to serve as a bottom material, adding 35 parts of acrylic acid and 120 parts of deionized water to serve as a material A, preparing 1.2 parts of mercaptopropionic acid and thioglycollic acid in a mass ratio of 1:2, 4.5 parts of ascorbic acid and 50 parts of deionized water into a material B, and adding 2.2 parts of ammonium persulfate and 60 parts of deionized water into a material C. Heating a water bath kettle to 35 ℃, placing a four-neck flask filled with base materials into the water bath kettle, adding 1/3C materials into the water bath kettle once, then dropwise adding A materials and B materials at a constant speed, dropwise adding the A materials for 3 hours, dropwise adding the B materials for 3 hours and 10 minutes, after the reaction is carried out for 1.2 hours, adjusting the pH in the reaction kettle to be 5 by using dilute sulfuric acid, then adding the rest C materials once, adding alkali to neutralize and supplement water until the total mass is 1000 parts after the dropwise adding of the A materials and the B materials is finished, then curing for 1 hour, naturally cooling to room temperature, and obtaining a polymer solution with the mass fraction of about 40%, namely the polymer for the stable pumping concrete.

The specific raw materials and the specific parameters of the preparation methods (the steps are the same) of examples 2 to 6 are different from those of example 1, and are specifically shown in the following tables 1 and 2 (table 1 is the raw material, table 2 is the parameter of the preparation method), and the representations not shown in table 2 are the same as those of example 1:

table 1 is a raw material composition comparison table of examples 1 to 6 of the present invention

Table 2 is a comparative table of reaction parameters for examples 1 to 6 of the present invention

The products prepared in the embodiments 1-6 of the invention and Qingdao Dingchang BS-2017-A concrete small materials are prepared into C50 concrete samples, and the following table is obtained through detection. (the gas content is tested according to the GB/T50080-2002 standard)

Table 3 shows the comparative table of the small concrete pumping performance of the concrete of examples 1 to 6 and Qingdao Dingchang BS-2017-A of the present invention

Table 4 shows the mechanical property comparison table of the concrete small materials of examples 1-6 and Qingdao Dingchang BS-2017-A of the present invention

From the table, it can be found that the fluidity of the cement paste detected by the test is very excellent, and the synthesis steps are simple and are favorable for popularization.

The BS-2017-A concrete small material and the 1d concrete sample of the example 1 are sampled for SEM test, and the results are shown in figure 1 and figure 2. In FIG. 1, it is evident that some short rods of ettringite and doughy gels, the hydration product is more compact; FIG. 2 shows that the hydration product is uniformly and densely distributed and has high compactness, which shows that the embodiment of the invention has good retardation and enhances the stable pumping performance of the cement paste.

The above embodiments are merely illustrative of the present invention and are not to be construed as limiting the invention. Although the present invention has been described in detail with reference to the embodiments, it should be understood by those skilled in the art that various combinations, modifications or equivalents may be made to the technical solution of the present invention without departing from the spirit and scope of the technical solution of the present invention, and the technical solution of the present invention is covered by the claims of the present invention.