CN112028536B

CN112028536B - Method for preparing environment-responsive polymer through composite assembly

Info

Publication number: CN112028536B
Application number: CN202010791462.5A
Authority: CN
Inventors: 王子明; 宋晓飞; 李婷; 宋作宝; 刘晓; 李晓宁; 曹虎; 赵攀
Original assignee: Cnbm Zhongyan Technology Co ltd; Shandong Zhongyan Building Materials Technology Co ltd; Beijing University of Technology
Current assignee: Cnbm Zhongyan Technology Co ltd; Shandong Zhongyan Building Materials Technology Co ltd; Beijing University of Technology
Priority date: 2020-08-07
Filing date: 2020-08-07
Publication date: 2022-02-08
Anticipated expiration: 2040-08-07
Also published as: CN112028536A

Abstract

The invention relates to a method for preparing an environment-responsive polymer by composite assembly. The invention adopts hydrophobic monomers, polysaccharide derivatives and the like as main reaction raw materials, and prepares a magnetic field response polymer by a method of graft polymerization, crosslinking reaction and composite assembly, namely, the hydrophobic monomers are graft polymerized firstly, then the polysaccharide derivatives and ferroferric oxide powder are crosslinked under the action of a crosslinking agent to obtain hydrogel, and finally the magnetic field response polymer is obtained by composite assembly. The method has the advantages of energy saving, high efficiency and simple operation, successfully prepares the magnetic field response polymer by the way of compositely assembling the branch structure polymer by the polysaccharide derivative hydrogel, shows multiple effects of excellent environmental response, maintaining the volume stability of concrete and the like, realizes the aim of improving the application performance of the concrete material by self-driving, and has good market competitiveness and application prospect.

Description

Method for preparing environment-responsive polymer through composite assembly

Technical Field

The invention relates to the technical field of magnetic field response polymers for cement concrete, in particular to a specific preparation method for synthesizing an environment response polymer by adopting hydrogel composite assembly of hydrophobic monomers which are firstly grafted and polymerized and then crosslinked with polysaccharide derivatives.

Background

Concrete is the building material with the largest application amount in modern building engineering, and is widely applied to engineering such as industry, water conservancy, agriculture, traffic, harbors and the like along with the needs of building engineering and the progress of scientific and technical development. However, due to factors such as concrete structure, material and environment, early cracking and shrinkage cracking of concrete are easily caused, which troubles concrete construction and influences concrete durability. Shrinkage is a key factor causing non-load cracks of a concrete structure, and is particularly large-fluidity concrete, pump concrete, high-strength concrete and the like doped with a high-efficiency water reducing agent and an ultrafine mineral admixture (ultrafine slag powder, silica fume and the like). Correspondingly, the cement specific surface area is greatly increased in the cement concrete industry to pursue early strength, high-activity ultrafine mineral admixtures are added, the water-cement ratio is reduced as far as possible, and the like, so that the internal relative humidity of the slurry after concrete pouring is rapidly reduced, the shrinkage is increased, the cracking problem is serious, and the stability and the safety of a concrete structure are threatened.

Smart materials and smart structural systems are one of the fastest growing areas in recent years, where stimulus-responsive polymer hydrogels have become a current research hotspot. Hydrogels can be classified into two categories according to their response to external stimuli: one is conventional hydrogel, which is not particularly sensitive to changes in the external environment; another class is environmentally sensitive hydrogels, which respond to stimuli caused by the environment to varying degrees and are intelligent. The intelligent environment-sensitive hydrogel comprises temperature-sensitive hydrogel, pH-sensitive hydrogel, magnetic-sensitive hydrogel, photosensitive hydrogel, pressure-sensitive hydrogel and the like, and is widely applied to actuators, valves, sensors, control release systems of medicines and other substances, artificial muscles of robot equipment, chemical storages, optical shutters, molecular separation systems and the like.

The continuous development of molecular structure design and synthesis methods in polymer disciplines provides theoretical basis for 'cutting' an ideal polymer structure. The development of polymers with characteristic structures and unique functions is favored by researchers more and more, so that hydrophobic monomers are introduced into the long chains of the carbohydrate derivatives, the characteristic hydrophobic polymers are designed and synthesized, and excellent anchoring adsorption and water absorption prevention behaviors are realized through the synergistic effect of the main side chains. The material with the structure has wide application prospect in polymer auxiliary agents such as adhesives, dispersing agents, solubilizing agents, surfactants and the like, green chemicals, biological medicine materials and electronic information materials.

Patent CN103819123A (published: 5/8/2014) reports a polymer with a rust-resistant function for mortar and concrete and a preparation method thereof, wherein the polymer comprises 5-20% of a shrinkage-reducing component and 5-20% of a water-soluble organic high-molecular rust-resistant component. The polymer can reduce the plastic shrinkage and the dry shrinkage of concrete, reduce the occurrence probability of dry shrinkage cracks of the concrete, thereby greatly reducing the risk of the shrinkage cracks of the concrete, preventing carbon steel from corroding and improving the durability of the concrete, and being nontoxic, tasteless, pollution-free to the environment, convenient to use and suitable for the concrete in various environments and conditions. However, the process of the invention is complicated, the shrinkage control effect of the concrete is not realized by using a hydrogel system, and the aim of spontaneously and intelligently controlling the concrete to reduce shrinkage cracking is achieved by using a magnetic response principle.

Patent CN107572859B (published: 2018, 01, 12) reports a polymer for recycled concrete, which is composed of the following raw materials in parts by weight: 3-6 parts of water glass, 0.5-2 parts of calcium oxide, 15-28 parts of polyacrylamide, 45-60 parts of fly ash, 0.1-0.8 part of potassium silicate, 2-8 parts of polyethylene glycol, 1-4 parts of polypropylene fiber, 2-5 parts of aloe, 3-12 parts of film forming aid and 50-70 parts of water. The product of the invention permeates into the interior of the recycled concrete, fills the micropores of the recycled concrete or has chemical reaction with substances in the recycled concrete to generate a substance with expansion compactness, can reduce the shrinkage of the recycled concrete, and simultaneously, the water glass and the film formation aiding substance form a layer of water retention film, which can prevent the evaporation of water and the volatilization of polymer components. The product is nontoxic, tasteless and pollution-free to the environment, is suitable for the surface layer of the recycled concrete in various environments and conditions, has good water retention capacity, can effectively control the shrinkage cracking of the recycled concrete, and has excellent application potential. However, the method only synthesizes the functional polymer through simple polymerization physical blending instead of a molecular structure design method, has higher production equipment requirement and energy consumption, increases the production cost, and is not widely applied to building engineering materials such as concrete and the like.

Patent CN107663036A (published: 2018, 2/6) reports a preparation method of an antifreezing concrete polymer, and belongs to the technical field of concrete materials. According to the invention, the hydrophobic groups in the polymer material are aggregated on the surface of an aqueous solution, so that the volatilization of water in a mortar pore solution is reduced, the surface tension in a capillary pore solution is effectively reduced, and the capillary pore pressure is reduced, thereby reducing the shrinkage and cracking phenomena of concrete, wherein the polymer can partially agglomerate to influence the functional effect due to excessively high doping amount. In addition, the calcium carbide particles are used as the air-entrapping modification main body, the contact between water and the calcium carbide is regulated and limited, the gas generation speed is reduced, a layer of hydrophobic film is wrapped outside the calcium carbide to block the contact between the hydrophobic film and the water, then the water slowly permeates into the calcium carbide under the swelling action of resin, and the gas is slowly released, so that the air-entrapping performance of the material is realized, and the frost resistance of the material is effectively improved. However, the invention only utilizes the hydrophobic group rather than the special molecular structure design of the hydrophobic polymer, and does not assemble with the modified hydrogel to realize intelligent controlled release, thereby having certain limitation and being difficult to implement and operate.

The polymer material for concrete described in the above patent has good application properties of suppressing shrinkage and resisting cracking. However, the products obtained by the above synthesis methods all have some disadvantages, and researchers mostly achieve the purpose of inhibiting the shrinkage cracking of concrete by the idea of reducing the surface tension or blending surface active substances, but rarely achieve the purpose by designing and synthesizing an environment-responsive polymer, and even do not utilize a hydrogel modified material to exert the effect of the environment responsiveness. The existing intelligent material action principle proves that the functional effect and the service performance of the polymer can be effectively regulated and controlled by assembling the adsorption polymer in the hydrogel modified by the environmental response. Therefore, an innovative molecular design synthetic route is utilized to obtain the environmental response polymer, so that the material has intelligent environmental response, has the characteristic performances of inhibiting concrete shrinkage and resisting water absorption, is beneficial to industrial production and popularization and application, and has no report on research at home and abroad.

Disclosure of Invention

The invention aims to provide a preparation process for preparing an environment-responsive polymer by composite assembly. The magnetic field response type polymer with excellent performance is obtained by grafting and polymerizing hydrophobic monomers to obtain an adsorption type hydrophobic polymer, performing crosslinking reaction modification on polysaccharide derivatives and ferroferric oxide powder under the action of a crosslinking agent to obtain hydrogel, and finally performing composite assembly. The invention is based on the advantage of intelligent hydrogel composite assembly, introduces ferroferric oxide powder with magnetic field responsiveness on the surface of hydrogel innovatively, and wraps the adsorption type hydrophobic polymer in the hydrogel, thereby ensuring that the hydrogel responds under the action of a magnetic field, realizing that the hydrophobic polymer is anchored on the surface of cement particles, inhibiting the shrinkage and cracking of cement concrete from the inside of the material better, and enriching the application of hydrogel chemical modification and composite assembly thereof in the field of cement concrete. The environment response type polymer synthesized by the method is different from the traditional hydrogel, the environment response release function of the polymer can realize intelligent regulation and control of polymer adsorption, and the polymer shows more excellent working characteristics and action effects than the polymer material for common cement concrete.

The invention provides a method for preparing an environment-responsive polymer by composite assembly, which is used for preparing a magnetic field-responsive polymer material by firstly carrying out graft polymerization on a hydrophobic monomer and then carrying out composite assembly on the hydrophobic monomer and hydrogel obtained by crosslinking a polysaccharide derivative and ferroferric oxide powder, and comprises the following conditions and steps:

(1) graft polymerization: adding a hydrophobic monomer and an organic solvent into a reactor, stirring and heating to 60-90 ℃, filling nitrogen, repeatedly deoxidizing for 10-30 minutes for 3-5 times, sealing, adding a molecular weight regulator, adding an acid solution of cerium ammonium salt with the mass fraction of 20-40%, stirring for 5-15 minutes, adding an aqueous solution of glucose derivatives with the mass fraction of 40-80%, reacting for 1-6 hours at a constant temperature, cooling to 20-40 ℃, adding an alkaline solution with the mass fraction of 10-50% to neutralize to a pH value of 6-8, removing the solvent by reduced pressure distillation, and adding an aqueous solution of an emulsifier with the mass fraction of 5-30%, thereby obtaining a polymer emulsion;

(2) and (3) crosslinking reaction: adding a polysaccharide derivative and deionized water into a reactor, stirring, heating to 50-80 ℃, introducing nitrogen to purge for 5-20 minutes, adding ferroferric oxide powder, ultrasonically and mechanically stirring, adding a cross-linking agent, stirring to react for 1-2 hours, pouring the mixed solution into a mold, cooling to 20-40 ℃, carrying out cross-linking reaction for 24-60 hours, demolding, and washing for 3-5 times by using deionized water to obtain hydrogel;

(3) and (3) composite assembly: adding the product hydrogel obtained in the step (2) into the product polymer emulsion obtained in the step (1), soaking for 6-12 hours, adding a flocculant aqueous solution with the mass fraction of 10% -40%, stirring for 20-50 minutes, washing with deionized water for 5-8 times, and then drying in vacuum to obtain the magnetic field response type polymer;

(4) and (3) response process: and (4) doping the magnetic field response type polymer obtained in the step (3) into fresh concrete, uniformly stirring, adding a magnetic field device after 0.5-24 hours, and applying a magnetic field for 24-60 hours to generate magnetic field response and generate a corresponding application performance effect.

The hydrophobic monomer in the step (1) is one or more of styrene, phenylisopropylene, vinyl toluene, phenylpropylene, methyl methacrylate, ethyl methacrylate and butyl methacrylate; the organic solvent in the step (1) is dimethyl sulfoxide, 1, 4-dioxane or dimethylformamide, and the mass ratio of the dosage to the hydrophobic monomer in the step (1) is 3-10: 1; the molecular weight regulator in the step (1) is isopropanol, n-dodecyl mercaptan or isooctyl 3-mercaptopropionate, and the molar ratio of the dosage of the molecular weight regulator to the hydrophobic monomer in the step (1) is 0.1-0.5: 1; the acid solution of cerium ammonium salt in the step (1) is nitric acid solution of cerium ammonium nitrate or sulfuric acid solution of cerium ammonium sulfate, and the molar ratio of the dosage of cerium ammonium salt to the hydrophobic monomer in the step (1) is 0.005-0.15: 1; the glucose derivative in the step (1) is one or more of gluconic acid, sodium gluconate, potassium gluconate, glucaric acid and D-glucuronic acid, and the molar ratio of the dosage to the hydrophobic monomer in the step (1) is 0.2-1: 1; the solute of the alkaline solution in the step (1) is sodium hydroxide, potassium hydroxide, ethylenediamine or triethylamine; the emulsifier in the step (1) is sodium dodecyl sulfate, sodium dodecyl benzene sulfonate, sodium stearate or sodium dodecyl diphenyl ether disulfonate, and the mass ratio of the dosage of the emulsifier to the hydrophobic monomer in the step (1) is 0.03-0.08: 1; the polysaccharide derivative in the step (2) is sodium alginate or hyaluronic acid, and the mass ratio of the use amount of the polysaccharide derivative to the deionized water in the step (2) is 1: 2.5-4; the mass ratio of the ferroferric oxide in the step (2) to the polysaccharide derivative in the step (2) is 0.2-0.8: 1; the cross-linking agent in the step (2) is glutaraldehyde, boric acid, epichlorohydrin or terephthalaldehyde, and the mass ratio of the dosage of the cross-linking agent to the polysaccharide derivative in the step (2) is 0.02-0.05: 1; the mass ratio of the hydrogel to the polymer emulsion in the step (3) is 1: 10-20; the flocculating agent in the step (3) is ferric sulfate, aluminum sulfate, sodium chloride or calcium chloride, and the mass ratio of the dosage to the hydrophobic monomer in the step (1) is 0.1-0.3: 1; the mass ratio of the magnetic field response type polymer in the step (4) to the cementing material in the fresh concrete is 0.01-0.1: 1; the magnetic field intensity in the step (4) is-500 KOe-500 KOe.

The molecular structural formula of the polymer obtained in step (1) in the method of the present invention is as follows:

wherein R is₁Is carboxyl, aldehyde or methylene hydroxyl; r₂Hydrogen, sodium or potassium; r₃Is hydrogen or methyl; r₄Is phenyl, carbomethoxy, carbethoxy, carbomethoxy, benzyl or o-tolyl;

wherein n is a positive integer representing the number of repeating units of each branch in the polymer, and n is in the range of 15 to 120.

Compared with the prior art, the method of the invention has the following beneficial effects:

1. based on the advantages of intelligent hydrogel composite assembly, the adsorption type hydrophobic polymer is obtained through hydrophobic monomer graft polymerization, the polysaccharide derivative and ferroferric oxide powder are subjected to crosslinking reaction modification under the action of a crosslinking agent to obtain hydrogel, and finally the magnetic field response type polymer is obtained through composite assembly.

2. The intelligent hydrogel is a material capable of making corresponding intelligent response by contacting with the stimulation of an external environment, can change the property of the structure or swelling property of the hydrogel by inducing the change of external temperature, illumination, magnetic field, electric field, pH value and the like or contacting with specific micromolecules, thereby playing a required function, innovatively introducing the hydrogel into the field of cement concrete, realizing a multifunctional effect by combining a molecular structure design principle, playing a unique response property of the hydrogel, having a wide application prospect and being a novel functional polymer for the concrete.

3. The invention designs and synthesizes the adsorption type hydrophobic polymer, innovatively realizes the composite assembly of the environment-responsive modified hydrogel in situ, the three-dimensional network structure of the adsorption type hydrophobic polymer can spontaneously generate gap change and release internal substances under the action of an external magnetic field, and the adsorption type hydrophobic polymer is not layered and phase-separated in the concrete, can be quickly anchored on the surface of cement particles in concrete slurry to form a compact polymer adsorption layer, realizes the hydrophobic water retention effect, and has remarkable technical advantages.

4. The preparation process of the invention has low energy consumption, safety, environmental protection, mild condition, cleanness, no pollution, simple and easy synthesis method, the used steps of graft copolymerization, crosslinking reaction, composite assembly and the like belong to common preparation processes, the preparation method does not depend on flammable and explosive chemical raw materials or complex catalytic systems, has no special requirements on equipment, enriches the preparation method of the functional polymer for synthesizing concrete, and shows excellent market potential and popularization value.

5. The environment response polymer synthesized by the invention can intelligently play a role under the action of a magnetic field, can enable the concrete material to show good effects of inhibiting shrinkage and resisting water absorption under a lower mixing amount, and shows consistent regularity at different ages. In addition, the synthetic method has the advantages of intelligence and high efficiency, the synthetic environment response polymer system is stable in state, strong in adaptability and excellent in performance indexes, technical innovation is facilitated, optimization and upgrading are facilitated, and the synthetic method has good economic benefits and application prospects.

Drawings

Fig. 1 is a graph showing the change in the encapsulation efficiency of examples 1 to 6.

Fig. 2 is a graph showing the change in the amount of the carrier in examples 1 to 6.

Fig. 3 is a graph showing the transmittance change before and after application of a magnetic field in examples 1 to 6.

FIG. 4 is a graph showing the change in water absorption of concrete in comparative example and examples 1 to 6.

Detailed Description

The present invention will be described in further detail with reference to examples, but the practice of the present invention is not limited thereto.

Example 1

Firstly, adding 30g of phenylpropylene and 90g of dimethylformamide into a reactor, stirring and heating to 90 ℃, filling nitrogen, repeatedly deoxidizing for 30 minutes for 5 times, sealing, adding 11.08g of isooctyl 3-mercaptopropionate, adding 17.8g of sulfuric acid solution of 25 mass percent of ammonium cerium sulfate, stirring for 15 minutes, adding 53.39g of aqueous solution of glucaric acid with the mass percent of 80 percent, reacting for 3 hours at constant temperature, cooling to 30 ℃, adding 25 mass percent of triethylamine solution, neutralizing until the pH value is 7, removing the solvent by reduced pressure distillation, and adding 30g of aqueous solution of 5 mass percent of sodium dodecyl diphenyl ether disulfonate to obtain polymer emulsion; adding 40g of sodium alginate and 160g of deionized water into a reactor, stirring and heating to 80 ℃, introducing nitrogen for purging for 10 minutes, adding 20g of ferroferric oxide powder, performing ultrasonic mechanical stirring, adding 0.8g of glutaraldehyde, performing stirring reaction for 2 hours, pouring the mixed solution into a mold, cooling to 30 ℃, performing crosslinking reaction for 48 hours, demolding, and washing for 3 times by using deionized water to obtain hydrogel; adding 5g of hydrogel into 50g of polymer emulsion, soaking for 10 hours, adding 90g of aqueous solution of calcium chloride with the mass fraction of 10%, stirring for 35 minutes, washing with deionized water for 8 times, and drying in vacuum to obtain a magnetic field response type polymer; 1196.3g of magnetic field response type polymer is mixed into 23926g of fresh concrete and evenly stirred, a magnetic field device is added after 10 hours, and a magnetic field intensity is applied for 200KOe for 24 hours, so that magnetic field response can be generated and a corresponding application performance effect can be generated.

Example 2

Firstly, adding 30g of vinyl toluene and 150g of dimethylformamide into a reactor, stirring and heating to 80 ℃, filling nitrogen, repeatedly deoxidizing for 20 minutes, sealing, adding 27.71g of isooctyl 3-mercaptopropionate, adding 6.98g of nitric acid solution of ammonium ceric nitrate with the mass fraction of 20%, stirring for 5 minutes, adding 104.1g of gluconic acid aqueous solution with the mass fraction of 40%, reacting for 6 hours at constant temperature, cooling to 40 ℃, adding ethylenediamine solution with the mass fraction of 30% to neutralize until the pH value is 6, removing the solvent by reduced pressure distillation, and adding 12g of sodium stearate aqueous solution with the mass fraction of 20%, thereby obtaining a polymer emulsion; adding 40g of hyaluronic acid and 120g of deionized water into a reactor, stirring and heating to 60 ℃, introducing nitrogen for purging for 20 minutes, adding 8g of ferroferric oxide powder, performing ultrasonic mechanical stirring, adding 2g of boric acid, performing stirring reaction for 1 hour, pouring the mixed solution into a mold, cooling to 40 ℃, performing crosslinking reaction for 24 hours, demolding, and washing for 5 times with deionized water to obtain hydrogel; adding 5g of hydrogel into 50g of polymer emulsion, soaking for 12 hours, adding 30g of aqueous solution of sodium chloride with the mass fraction of 20%, stirring for 20 minutes, washing with deionized water for 8 times, and drying in vacuum to obtain a magnetic field response type polymer; 1206g of magnetic field response type polymer is mixed into 24120g of fresh concrete and uniformly stirred, a magnetic field device is added after 20 hours, and magnetic field intensity is applied for 30 hours at-300 KOe, so that magnetic field response can be generated and corresponding application performance effects can be generated.

Example 3

Firstly, adding 30g of ethyl methacrylate and 210g of dimethyl sulfoxide into a reactor, stirring and heating to 80 ℃, filling nitrogen for repeatedly removing oxygen for 10 minutes, sealing, adding 6.32g of isopropanol, then adding 28.85g of nitric acid solution of ammonium ceric nitrate with the mass fraction of 40%, stirring for 12 minutes, then adding 51.58g of gluconic acid aqueous solution with the mass fraction of 50%, reacting for 6 hours at constant temperature, cooling to 35 ℃, adding 10% of potassium hydroxide solution with the mass fraction of 10% for neutralizing until the pH value is 7, removing the solvent by reduced pressure distillation, and then adding 10.5g of aqueous solution of sodium stearate with the mass fraction of 20% to obtain polymer emulsion; adding 40g of hyaluronic acid and 100g of deionized water into a reactor, stirring and heating to 50 ℃, introducing nitrogen for purging for 20 minutes, adding 32g of ferroferric oxide powder, performing ultrasonic mechanical stirring, adding 1.2g of epoxy chloropropane, performing stirring reaction for 2 hours, pouring the mixed solution into a mold, cooling to 35 ℃, performing crosslinking reaction for 60 hours, demolding, and washing for 5 times by using deionized water to obtain hydrogel; adding 5g of hydrogel into 75g of polymer emulsion, soaking for 12 hours, adding 15g of aqueous solution of sodium chloride with the mass fraction of 20%, stirring for 30 minutes, washing with deionized water for 8 times, and drying in vacuum to obtain a magnetic field response type polymer; 1215.6g of magnetic field response type polymer is mixed into 24312g of fresh concrete and evenly stirred, a magnetic field device is added after 12 hours, and a magnetic field intensity is applied for 500KOe24 hours, so that magnetic field response can be generated and a corresponding application performance effect can be generated.

Example 4

Firstly, adding 30g of methyl methacrylate and 300g of 1, 4-dioxane into a reactor, stirring and heating to 60 ℃, filling nitrogen, repeatedly deoxidizing for 20 minutes, sealing, adding 18.18g of isooctyl 3-mercaptopropionate, adding 2.74g of nitric acid solution of 30 mass percent of ammonium ceric nitrate, stirring for 10 minutes, adding 19.4g of D-glucuronic acid aqueous solution with 60 mass percent, reacting for 4 hours at constant temperature, cooling to 20 ℃, adding 10 mass percent of sodium hydroxide solution to neutralize to pH 7, removing the solvent by reduced pressure distillation, and adding 4g of 30 mass percent of sodium dodecyl sulfate aqueous solution to obtain polymer emulsion; adding 40g of sodium alginate and 160g of deionized water into a reactor, stirring, heating to 80 ℃, introducing nitrogen for purging for 5 minutes, adding 12g of ferroferric oxide powder, performing ultrasonic mechanical stirring, adding 1.6g of terephthalaldehyde, performing stirring reaction for 2 hours, pouring the mixed solution into a mold, cooling to 20 ℃, performing crosslinking reaction for 48 hours, demolding, and washing for 4 times by using deionized water to obtain hydrogel; adding 5g of hydrogel into 100g of polymer emulsion, soaking for 6 hours, adding 15g of aqueous solution of ferric sulfate with the mass fraction of 20%, stirring for 45 minutes, washing with deionized water for 7 times, and drying in vacuum to obtain a magnetic field response type polymer; 1192.1g of magnetic field response type polymer is mixed into 23842g of fresh concrete and evenly stirred, a magnetic field device is added after 24 hours, and magnetic field intensity is applied for 48 hours at-500 KOe, thus generating magnetic field response and generating corresponding application performance effect.

Example 5

Firstly, adding 30g of styrene and 90g of dimethyl sulfoxide into a reactor, stirring and heating to 70 ℃, filling nitrogen for 3 times, deoxidizing for 30 minutes, sealing, adding 5.19g of isopropanol, then adding 79.05g of nitric acid solution of ammonium ceric nitrate with the mass fraction of 20%, stirring for 12 minutes, then adding 24.23g of gluconic acid aqueous solution with the mass fraction of 70%, reacting for 2 hours at constant temperature, cooling to 20 ℃, adding 50% of sodium hydroxide solution with the mass fraction, neutralizing until the pH value is 7, removing the solvent by reduced pressure distillation, and then adding 9g of aqueous solution of sodium dodecyl sulfate with the mass fraction of 10%, thus obtaining polymer emulsion; adding 40g of hyaluronic acid and 100g of deionized water into a reactor, stirring and heating to 70 ℃, introducing nitrogen for purging for 12 minutes, adding 24g of ferroferric oxide powder, performing ultrasonic mechanical stirring, adding 2g of glutaraldehyde, performing stirring reaction for 2 hours, pouring the mixed solution into a mold, cooling to 20 ℃, performing crosslinking reaction for 60 hours, demolding, and washing for 5 times with deionized water to obtain hydrogel; adding 5g of hydrogel into 100g of polymer emulsion, soaking for 10 hours, adding 10g of aqueous solution of ferric sulfate with the mass fraction of 30%, stirring for 50 minutes, washing for 6 times by using deionized water, and then drying in vacuum to obtain the magnetic field response type polymer; 1181g of magnetic field response type polymer is mixed into 23620g of fresh concrete and evenly stirred, a magnetic field device is added after 2 hours, and magnetic field intensity is applied for 60 hours at-300 KOe, so that magnetic field response can be generated and corresponding application performance effects can be generated.

Example 6

Firstly, adding 30g of phenylisopropylene and 240g of 1, 4-dioxane into a reactor, stirring and heating to 60 ℃, filling nitrogen, repeatedly deoxidizing for 10 minutes for 5 times, sealing, adding 5.14g of n-dodecyl mercaptan, adding 5.93g of nitric acid solution of 30 mass percent of ammonium ceric nitrate, stirring for 8 minutes, adding 55.42g of 50 mass percent sodium gluconate aqueous solution, reacting for 5 hours at constant temperature, cooling to 35 ℃, adding 20 mass percent potassium hydroxide solution, neutralizing to pH 8, removing the solvent by reduced pressure distillation, and adding 6g of 25 mass percent sodium dodecyl benzene sulfonate aqueous solution to obtain polymer emulsion; adding 40g of sodium alginate and 160g of deionized water into a reactor, stirring and heating to 60 ℃, introducing nitrogen to purge for 15 minutes, adding 32g of ferroferric oxide powder, performing ultrasonic mechanical stirring, adding 0.8g of terephthalaldehyde, performing stirring reaction for 1 hour, pouring the mixed solution into a mold, cooling to 35 ℃, performing crosslinking reaction for 24 hours, demolding, and washing for 5 times by using deionized water to obtain hydrogel; adding 5g of hydrogel into 75g of polymer emulsion, soaking for 6 hours, adding 22.5g of an aqueous solution of aluminum sulfate with the mass fraction of 40%, stirring for 30 minutes, washing with deionized water for 5 times, and then drying in vacuum to obtain a magnetic field response type polymer; 1204.4g of magnetic field response type polymer is mixed into 24088g of fresh concrete and evenly stirred, a magnetic field device is added after 10 hours, and a magnetic field intensity is applied for 24 hours at 500KOe, so that magnetic field response can be generated and a corresponding application performance effect can be generated.

The implementation effect is as follows:

the encapsulation efficiency is shown in fig. 1, the amount of carrier is shown in fig. 2, and the magnetic field response of the transmittance is shown in fig. 3. As can be seen from FIG. 3, the transmittance is significantly reduced after the application of the magnetic field, which indicates that the environment-responsive polymer can generate the environment response in the presence of the magnetic field, and the released adsorptive hydrophobic polymer shows stronger hydrophobicity.

1. Water absorption of concrete

The concrete material composition ratio is shown in table 1, and the flexural anchoring content for fixing the synthesized environment responsive polymer of the present invention is 5% of the cement amount. The comparative example used was concrete without the addition of the environmentally responsive polymer, with the remaining component ratios unchanged.

TABLE 1 concrete mix proportion (kg/m)³)

Cement

Fly ash

Mineral powder

Sand

Stone

Water (W)

Water reducing agent

Ambient response aggregationArticle (A)

223

72

65

845

1050

162

0.6％

5％

As can be seen from fig. 4, the environmental response polymer can generate environmental response in the presence of a magnetic field, and the released adsorption-type hydrophobic polymer significantly reduces the water absorption rate, effectively reduces the entry of external moisture, and is beneficial to improving the durability of concrete.

2. Shrinkage reducing effect of concrete

The shrinkage test results of the concrete prepared according to table 1 are shown in table 2, the anchoring amount of the environmental responsive polymer synthesized according to the present invention was fixed to 5% of the amount of cement, the comparative example used was the concrete to which the environmental responsive polymer was not added, and the proportions of the remaining components were not changed.

TABLE 2 concrete shrinkage test results

Polymer and method of making same	The blending amount is%	1d[×10^-4]	7d[×10^-4]	14d[×10^-4]	28d[×10^-4]
						Comparative example	0	-1.32	-4.20	-6.03	-8.91
Example 1	5	-0.62	-3.81	-5.07	-6.20
						Example 2	5	-0.46	-3.50	-4.10	-6.05
Example 3	5	-0.93	-3.92	-5.54	-7.12
						Example 4	5	-0.52	-3.69	-4.57	-6.70
Example 5	5	-0.08	-2.29	-3.20	-4.68
						Example 6	5	-0.15	-2.78	-3.79	-5.62

As can be seen from table 2, the environmental response polymer synthesized by the example of the present invention can significantly inhibit the shrinkage of concrete, and the environmental response polymer achieves the shrinkage reduction effect by releasing the adsorptive hydrophobic polymer under the action of an applied magnetic field, which is different from the action mechanism of a typical concrete polymer. As can be seen from the shrinkage results in Table 2, the environmentally responsive polymers synthesized in the examples of the present invention can effectively reduce the drying shrinkage of concrete, and the shrinkage of 1d, 7d, 14d and 28d is better than that of the comparative examples.

Claims

1. The method for preparing the environment-responsive polymer by composite assembly is characterized by comprising the following steps:

wherein, the hydrophobic monomer in the step (1) is one or more of styrene, phenylisopropylene, vinyl toluene, phenylpropylene, methyl methacrylate, ethyl methacrylate and butyl methacrylate; the organic solvent in the step (1) is dimethyl sulfoxide, 1, 4-dioxane or dimethylformamide, and the mass ratio of the dosage to the hydrophobic monomer in the step (1) is 3-10: 1; the molecular weight regulator in the step (1) is isopropanol, n-dodecyl mercaptan or isooctyl 3-mercaptopropionate, and the molar ratio of the dosage of the molecular weight regulator to the hydrophobic monomer in the step (1) is 0.1-0.5: 1; the acid solution of cerium ammonium salt in the step (1) is nitric acid solution of cerium ammonium nitrate or sulfuric acid solution of cerium ammonium sulfate, and the molar ratio of the dosage of cerium ammonium salt to the hydrophobic monomer in the step (1) is 0.005-0.15: 1; the glucose derivative in the step (1) is one or more of gluconic acid, sodium gluconate, potassium gluconate, glucaric acid and D-glucuronic acid, and the molar ratio of the dosage to the hydrophobic monomer in the step (1) is 0.2-1: 1; the solute of the alkaline solution in the step (1) is sodium hydroxide, potassium hydroxide, ethylenediamine or triethylamine; the emulsifier in the step (1) is sodium dodecyl sulfate, sodium dodecyl benzene sulfonate, sodium stearate or sodium dodecyl diphenyl ether disulfonate, and the mass ratio of the dosage of the emulsifier to the hydrophobic monomer in the step (1) is 0.03-0.08: 1; the polysaccharide derivative in the step (2) is sodium alginate or hyaluronic acid, and the mass ratio of the use amount of the polysaccharide derivative to the deionized water in the step (2) is 1: 2.5-4; the mass ratio of the ferroferric oxide in the step (2) to the polysaccharide derivative in the step (2) is 0.2-0.8: 1; the cross-linking agent in the step (2) is glutaraldehyde, boric acid, epichlorohydrin or terephthalaldehyde, and the mass ratio of the dosage of the cross-linking agent to the polysaccharide derivative in the step (2) is 0.02-0.05: 1; the mass ratio of the hydrogel to the polymer emulsion in the step (3) is 1: 10-20; the flocculating agent in the step (3) is ferric sulfate, aluminum sulfate, sodium chloride or calcium chloride, and the mass ratio of the dosage to the hydrophobic monomer in the step (1) is 0.1-0.3: 1.

2. The method of claim 1, wherein the polymer of step (1) has the following molecular formula:

3. Use of a magnetic field-responsive polymer obtainable by the process of claim 1, wherein: the magnetic field response type polymer obtained in the step (3) is mixed into fresh concrete and stirred uniformly, a magnetic field device is added after 0.5 to 24 hours, and a magnetic field is applied for 24 to 60 hours, so that magnetic field response can be generated; the mass ratio of the magnetic field response type polymer to the cementing material in the fresh concrete is 0.01-0.1: 1; the magnetic field intensity is-500 KOe-500 KOe.