A high-performance water-retaining and thickening material for dry-mixed building mortar and its preparation method

Abstract

This invention discloses a high-performance water-retaining and thickening material for dry-mixed building mortar and its preparation method, relating to the field of thickening material technology. The high-performance water-retaining and thickening material for dry-mixed building mortar comprises the following raw materials in parts by weight: high-titanium heavy slag: 40-60 parts, fly ash: 20-40 parts, bentonite: 10-30 parts, water-reducing agent: 6-8 parts, thickener: 0.5-1.5 parts, early-strength agent: 3-6 parts, and cellulose ether: 1-3 parts. The high-performance water-retaining and thickening material for dry-mixed building mortar prepared by this invention exhibits good compressive strength, water retention rate, and low consistency loss rate.

Description

Technical Field

[0001] This invention relates to the field of thickening materials technology, specifically to a high-performance water-retaining thickening material for dry-mixed building mortar and its preparation method. Background Technology

[0002] In the construction industry, dry-mixed mortar is an important building material, and its performance is crucial to ensuring the quality of construction projects. Water-retaining and thickening materials, as key components of dry-mixed mortar, play an indispensable role.

[0003] Traditional water-retaining and thickening materials for dry-mix mortar have some limitations. On the one hand, some water-retaining and thickening materials fail to achieve the desired thickening effect, which can worsen the workability of dry-mix mortar. For example, excessive or insufficient flowability can hinder plastering, masonry, and other operations, affecting construction efficiency and quality. On the other hand, some materials have poor water retention, leading to rapid moisture loss during construction. This can cause shrinkage and cracking during the hardening process, affecting the bond strength between the mortar and the substrate and reducing the overall structural stability of the building.

[0004] Chinese invention patent CN104003646A discloses a water-retaining and thickening material for dry-mixed mortar and its application. This material utilizes ultrafine slag powder as the main raw material and is composed of ultrafine slag powder, palygorskite, desulfurized gypsum, and hydroxypropyl starch ether. The water-retaining and thickening material prepared by this invention can significantly reduce the segregation of ordinary dry-mixed mortar, improve the uniformity, stability, and workability of the mixture, and enhance the strength and durability of ordinary dry-mixed mortar. However, it has a relatively large consistency loss rate. Summary of the Invention

[0005] To address the shortcomings of existing technologies, the purpose of this invention is to provide a high-performance water-retaining and thickening material for dry-mixed mortar in construction and its preparation method.

[0006] To achieve the above objectives, the present invention provides the following technical solution:

[0007] A high-performance water-retaining and thickening material for dry-mixed building mortar comprises the following raw materials in parts by weight:

[0008] High-titanium heavy slag: 40-60 parts, fly ash: 20-40 parts, bentonite: 10-30 parts, water-reducing agent: 6-8 parts, thickener: 0.5-1.5 parts, early strength agent: 3-6 parts, cellulose ether: 1-3 parts;

[0009] The thickener is prepared by the following method:

[0010] S1: ε-caprolactone reacts with 12-hydroxystearic acid to form a copolymer;

[0011] S2: Guar gum reacts with copolymers to produce modified guar gum;

[0012] S3: Modified guar gum reacts with borax to produce a thickener.

[0013] In step S1, the mass ratio of ε-caprolactone to 12-hydroxystearic acid is (5-8):2.

[0014] In step S2, the mass ratio of guar gum to copolymer is 10:(1-2).

[0015] In step S3, the mass ratio of modified guar gum to borax is 10:(0.5-1).

[0016] The water-reducing agent is prepared by the following method:

[0017] A1: Sulfonated lignin reacts with acryloyl chloride to produce modified lignin;

[0018] A2: Modified lignin reacts with acrylic acid and ethylene glycol monovinyl polyethylene glycol ether to produce a water-reducing agent.

[0019] In step A1, the mass ratio of sulfonated lignin to acryloyl chloride is 1:0.1.

[0020] In step A2, the mass ratio of modified lignin to acrylic acid and ethylene glycol monovinyl polyethylene glycol ether is 10:1.5:1.5.

[0021] The early strength agent is a mixture of triisopropanolamine, anhydrous calcium sulfoaluminate, and aluminum sulfate.

[0022] The mass ratio of the triisopropanolamine, anhydrous calcium sulfoaluminate and aluminum sulfate is 1:(1-2):(1-3).

[0023] A method for preparing a high-performance water-retaining and thickening material for dry-mixed building mortar includes the following steps:

[0024] (1) Weigh out the following by weight: high titanium heavy slag: 40-60 parts, fly ash: 20-40 parts, bentonite: 10-30 parts, water reducing agent: 6-8 parts, thickener: 0.5-1.5 parts, early strength agent: 3-6 parts, cellulose ether: 1-3 parts;

[0025] (2) The high-titanium heavy slag is crushed, dried and ultra-fine ground to obtain high-titanium heavy slag powder; the high-titanium heavy slag powder is mixed with fly ash at high speed to obtain ultra-fine mixed powder.

[0026] (3) Mix the ultrafine mixed powder with bentonite, water-reducing agent, thickener, early strength agent and cellulose ether evenly to obtain a high-performance water-retaining and thickening material for dry-mixed mortar.

[0027] Due to the adoption of the above technical solutions, the beneficial effects of the present invention include:

[0028] The water-retaining and thickening material prepared in this application, after adding novel thickeners and water-reducing agents, is applied to mortar, which significantly improves the compressive strength and water retention of the mortar and reduces the consistency loss rate. Detailed Implementation

[0029] The following description, in conjunction with specific embodiments, provides further details, but the present invention is not limited to these embodiments.

[0030] Example 1: Preparation of thickener:

[0031] S1: Add 300 ml of anhydrous toluene and 20 g of 12-hydroxystearic acid to the reactor, stir, purge with nitrogen, and circulate under vacuum three times (10 min each time). Stir for 20 min, add 0.1 g of catalyst stannous octoate, then heat to 80 °C, slowly add 50 g of ε-caprolactone dropwise over 1 h, maintain the temperature for 5 h, then heat to 85 °C and react for 6 h. Cool to room temperature, distill under reduced pressure at 60 °C for 3 h, then add 200 ml of DCM, stir to dissolve, slowly add 500 ml of cold diethyl ether, stir, precipitate, filter, and dry under vacuum at 50 °C for 8 h to obtain the copolymer with a number-average molecular weight of 1030 (theoretical value 1050). The reaction equation is shown below:

[0032]

[0033] S2: Under nitrogen protection, 500 ml of anhydrous dichloromethane, 100 g of copolymer, 0.11 mol of trimethylchlorosilane and 0.16 mol of imidazole were added to the reactor in an ice bath. The mixture was stirred for 2 h, then the reaction was continued at room temperature for 4 h. The reaction was quenched by adding 150 ml of saturated NaHCO3 solution. The organic phase was separated, and the aqueous phase was back-extracted with 100 ml of dichloromethane. The organic phases were combined, washed with 150 ml of saturated brine, dried with 50 g of anhydrous Na2SO4, and distilled under reduced pressure at 35 °C for 3 h to obtain the hydroxyl-protected copolymer.

[0034] The hydroxyl-protected copolymer obtained above was added to a reactor containing 400 ml of anhydrous THF, followed by the addition of 22.7 g DCC and 1.2 g DMAP. The carboxyl groups were activated at 50 °C for 2 h. Then, 1000 g of guar gum was slowly added to 10 LDMSO and stirred at high speed to swell, resulting in a guar gum solution. The guar gum solution was slowly added to the reactor and stirred at high speed. The reaction was carried out at 55 °C for 24 h. After the reaction was completed, 0.12 mol of tetrabutylammonium fluoride was added and stirred at room temperature for 3 h to remove the protecting groups. The reaction solution was dialyzed with deionized water (MWCO = 8000 Da) for 72 h and then freeze-dried at -50 °C for 24 h to obtain modified guar gum. During this reaction, the carboxyl groups in the copolymer underwent an esterification reaction with some of the hydroxyl groups in the guar gum.

[0035] S3: Add 400ml DMSO and 100g modified guar gum to the reactor and stir for 2h. Then slowly add borax aqueous solution (5g borax dissolved in 25ml 50℃ deionized water) dropwise over 20min. After the addition is complete, raise the temperature to 50℃ and continue the reaction for 4h. Add 5mL 1M HCl to adjust the pH to 7.0 and distill under reduced pressure at 50℃ for 5h to obtain the thickener. During this reaction, some hydroxyl groups in the modified guar gum react with B-OH in the borax to form borate ester bonds.

[0036] Example 2: Preparation of thickener:

[0037] S1: Add 300 ml of anhydrous toluene and 20 g of 12-hydroxystearic acid to the reactor, stir, purge with nitrogen, and circulate under vacuum three times (10 min each time). Stir for 20 min, add 0.1 g of catalyst stannous octoate, then heat to 80 °C, slowly add 60 g of ε-caprolactone dropwise for 1 h, and react at a constant temperature for 5 h. Then heat to 85 °C and react for 6 h, cool to room temperature, and distill under reduced pressure at 60 °C for 3 h. Then add 200 ml of DCM, stir to dissolve, slowly add 500 ml of cold diethyl ether and stir to precipitate, filter, and dry under vacuum at 50 °C for 8 h to obtain the copolymer with a number average molecular weight of 1280 (theoretical value 1200).

[0038] S2: Under nitrogen protection, 500 ml of anhydrous dichloromethane, 150 g of copolymer, 0.15 mol of trimethylchlorosilane and 0.2 mol of imidazole were added to the reactor in an ice bath. The mixture was stirred for 2 h, then the reaction was continued at room temperature for 4 h. The reaction was quenched by adding 150 ml of saturated NaHCO3 solution. The organic phase was separated, and the aqueous phase was back-extracted with 100 ml of dichloromethane. The organic phases were combined, washed with 150 ml of saturated brine, dried with 50 g of anhydrous Na2SO4, and distilled under reduced pressure at 35 °C for 3 h to obtain the hydroxyl-protected copolymer.

[0039] All of the hydroxyl-protected copolymers prepared above were added to a reactor containing 500 ml of anhydrous THF, followed by the addition of 34 g DCC and 1.8 g DMAP. The carboxyl groups were activated at 50 °C for 2 h. Then, 1000 g of guar gum was slowly added to 10 LDMSO and stirred at high speed to swell, resulting in a guar gum solution system. The guar gum solution system was slowly added to the reactor and stirred at high speed, reacting at 55 °C for 24 h. After the reaction was completed, 0.16 mol of tetrabutylammonium fluoride was added and stirred at room temperature for 3 h to remove the protecting groups. The reaction solution was dialyzed with deionized water (MWCO = 8000 Da) for 72 h and then freeze-dried at -50 °C for 24 h to obtain modified guar gum.

[0040] S3: Add 400ml DMSO and 100g modified guar gum to the reactor and stir for 2h. Then slowly add borax aqueous solution (8g borax dissolved in 35ml 50℃ deionized water) dropwise over 20min. After the addition is complete, raise the temperature to 55℃ and continue the reaction for 3h. Add 5mL 1M HCl to adjust the pH to 7.0 and distill under reduced pressure at 50℃ for 5h to obtain the thickener.

[0041] Example 3: Preparation of thickener:

[0042] S1: Add 300 ml of anhydrous toluene and 20 g of 12-hydroxystearic acid to the reactor, stir, purge with nitrogen, and circulate under vacuum three times (10 min each time). Stir for 20 min, add 0.1 g of catalyst stannous octoate, then heat to 80 °C, slowly add 80 g of ε-caprolactone dropwise for 1 h, and react at a constant temperature for 5 h. Then heat to 90 °C and react for 4 h, cool to room temperature, and distill under reduced pressure at 60 °C for 3 h. Then add 200 ml of DCM, stir to dissolve, slowly add 500 ml of cold diethyl ether and stir to precipitate, filter, and dry under vacuum at 50 °C for 8 h to obtain the copolymer with a number average molecular weight of 1690 (theoretical value 1500).

[0043] S2: Under nitrogen protection, 600 ml of anhydrous dichloromethane, 200 g of copolymer, 0.16 mol of trimethylchlorosilane and 0.24 mol of imidazole were added to the reactor in an ice bath. The mixture was stirred for 2 h, then the reaction was continued at room temperature for 4 h. The reaction was quenched by adding 150 ml of saturated NaHCO3 solution. The organic phase was separated, and the aqueous phase was back-extracted with 100 ml of dichloromethane. The organic phases were combined, washed with 150 ml of saturated brine, dried with 50 g of anhydrous Na2SO4, and distilled under reduced pressure at 35 °C for 3 h to obtain the hydroxyl-protected copolymer.

[0044] All of the hydroxyl-protected copolymers prepared above were added to a reactor containing 600 ml of anhydrous THF, followed by the addition of 45 g DCC and 2.4 g DMAP. The carboxyl groups were activated at 50 °C for 2 h. Then, 1000 g of guar gum was slowly added to 10 LDMSO and stirred at high speed to swell, resulting in a guar gum solution. The guar gum solution was slowly added to the reactor and stirred at high speed for 24 h at 55 °C. After the reaction was completed, 0.16 mol of tetrabutylammonium fluoride was added and stirred at room temperature for 3 h to remove the protecting groups. The reaction solution was dialyzed with deionized water (MWCO = 8000 Da) for 72 h and then freeze-dried at -50 °C for 24 h to obtain modified guar gum.

[0045] S3: Add 400ml DMSO and 100g modified guar gum to the reactor and stir for 2h. Then slowly add borax aqueous solution (10g borax dissolved in 50ml 50℃ deionized water) dropwise over 20min. After the addition is complete, raise the temperature to 55℃ and continue the reaction for 2h. Add 5mL 1M HCl to adjust the pH to 7.0 and distill under reduced pressure at 50℃ for 5h to obtain the thickener.

[0046] Example 4: Preparation of water-reducing agent:

[0047] A1: Under nitrogen protection, 400 ml DMSO, 100 g sulfonated lignin, 2 g DMAP catalyst, and 0.8 mol triethylamine were added to the reactor. Under ice bath conditions, 10 g acryloyl chloride was slowly added dropwise over 20 min. After the addition was complete, the temperature was raised to 40 °C, and the reaction was carried out for 8 h. Then, the mixture was distilled under reduced pressure at 50 °C for 3 h, followed by washing three times with 200 ml of saturated sodium chloride solution each time. The mixture was then dried under vacuum at 60 °C for 3 h to obtain modified lignin. The reaction equation is shown below:

[0048]

[0049] A2: Add 800ml DMSO, 100g modified lignin, 15g ethylene glycol monovinyl polyethylene glycol ether (EPEG-3000), and 15g acrylic acid to the reactor, stir and mix well, then add 2g initiator benzoyl peroxide and 1.5g chain transfer agent 3-mercaptopropionic acid. Heat to 70℃ and react for 5 hours, then cool to room temperature. Adjust the pH to 7 with 30wt% NaOH solution, and distill under reduced pressure at 60℃ for 4 hours to obtain the water-reducing agent. The reaction equation is shown below:

[0050]

[0051] Example 5: Preparation of high-performance water-retaining and thickening material for dry-mixed building mortar:

[0052] (1) Weigh: 400g of high-titanium heavy slag, 200g of fly ash, 100g of bentonite, 60g of water-reducing agent (prepared in Example 4), 5g of thickener (prepared in Example 1), 30g of early strength agent (10g of triisopropanolamine, 10g of anhydrous calcium sulfoaluminate and 10g of aluminum sulfate), and 10g of cellulose ether;

[0053] (2) Add the high-titanium heavy slag to a jaw crusher for crushing for 20 minutes, dry it at 100°C for 40 minutes using a rotary dryer, then add it to a vertical roller mill for grinding, and pass it through a 10-mesh sieve to obtain high-titanium heavy slag micro powder; mix the high-titanium heavy slag micro powder with fly ash at high speed, stir at 1500 rpm for 45 minutes to obtain ultrafine mixed micro powder.

[0054] (3) Mix the ultrafine mixed powder with bentonite, water-reducing agent, thickener, early strength agent and cellulose ether evenly, with a speed of 5000 r / min and a mixing time of 30 min, to obtain a high-performance water-retaining and thickening material for dry-mixed mortar.

[0055] Example 6: Preparation of high-performance water-retaining and thickening material for dry-mixed building mortar:

[0056] (1) Weigh: 500g of high-titanium heavy slag, 300g of fly ash, 200g of bentonite, 70g of water-reducing agent (prepared in Example 4), 10g of thickener (prepared in Example 2), 45g of early strength agent (10g of triisopropanolamine, 15g of anhydrous calcium sulfoaluminate and 20g of aluminum sulfate), and 20g of cellulose ether;

[0057] (2) Add the high-titanium heavy slag to a jaw crusher for crushing for 20 minutes, dry it at 100°C for 40 minutes using a rotary dryer, then add it to a vertical roller mill for grinding, and pass it through a 10-mesh sieve to obtain high-titanium heavy slag micro powder; mix the high-titanium heavy slag micro powder with fly ash at high speed, stir at 1500 rpm for 45 minutes to obtain ultrafine mixed micro powder.

[0058] (3) Mix the ultrafine mixed powder with bentonite, water-reducing agent, thickener, early strength agent and cellulose ether evenly, with a speed of 5000 r / min and a mixing time of 30 min, to obtain a high-performance water-retaining and thickening material for dry-mixed mortar.

[0059] Example 7: Preparation of high-performance water-retaining and thickening material for dry-mixed building mortar:

[0060] (1) High-titanium heavy slag: 600g, fly ash: 400g, bentonite: 300g, water-reducing agent (prepared in Example 4): 80g, thickener (prepared in Example 3): 15g, early strength agent (10g triisopropanolamine, 20g anhydrous calcium sulfoaluminate and 30g aluminum sulfate): 60g, cellulose ether: 30g;

[0061] (2) Add the high-titanium heavy slag to a jaw crusher for crushing for 20 minutes, dry it at 100°C for 40 minutes using a rotary dryer, then add it to a vertical roller mill for grinding, and pass it through a 10-mesh sieve to obtain high-titanium heavy slag micro powder; mix the high-titanium heavy slag micro powder with fly ash at high speed, stir at 1500 rpm for 45 minutes to obtain ultrafine mixed micro powder.

[0062] (3) Mix the ultrafine mixed powder with bentonite, water-reducing agent, thickener, early strength agent and cellulose ether evenly, with a speed of 5000 r / min and a mixing time of 30 min, to obtain a high-performance water-retaining and thickening material for dry-mixed mortar.

[0063] Comparative Example 1

[0064] The raw material composition and process of the high-performance water-retaining and thickening material for dry-mixed building mortar are basically the same as those in Example 6, except that the thickener is replaced with an equal weight of a thickener prepared by the following method:

[0065] The preparation method of the thickener is basically the same as that in Example 2, except that the 12-hydroxystearic acid in step S1 is replaced with an equimolar amount of 3-hydroxypropionic acid.

[0066] Comparative Example 2

[0067] The raw material composition and process of the high-performance water-retaining and thickening material for dry-mixed mortar are basically the same as those in Example 6. The difference is that the thickener is replaced with an equal weight of the modified guar gum prepared by step S2 of Example 2.

[0068] Comparative Example 3

[0069] The raw material composition and process of the high-performance water-retaining and thickening material for dry-mixed building mortar are basically the same as those in Example 6, except that the thickener is replaced with an equal weight of a thickener prepared by the following method:

[0070] Add 400 ml DMSO and 100 g guar gum to the reactor and stir for 2 h. Then slowly add 20 ml borax aqueous solution (8 g borax dissolved in 35 ml deionized water) dropwise over 20 min. After the addition is complete, raise the temperature to 50 °C and continue the reaction for 4 h. Add 5 mL 1 M HCl to adjust the pH to 7.0 and distill under reduced pressure at 50 °C for 5 h to obtain the thickener.

[0071] Comparative Example 4

[0072] The raw material composition and process of the high-performance water-retaining and thickening material for dry-mixed building mortar are basically the same as those in Example 6, except that the water-reducing agent is replaced with an equal weight of water-reducing agent prepared by the following method:

[0073] The preparation method of the water-reducing agent is basically the same as that in Example 4, except that the ethylene glycol monovinyl polyethylene glycol ether in step A2 is replaced with an equal weight of 2-ethyleneoxyethanol.

[0074] Comparative Example 5

[0075] The raw material composition and process of the high-performance water-retaining and thickening material for dry-mixed building mortar are basically the same as those in Example 6, except that the water-reducing agent is replaced with an equal weight of water-reducing agent prepared by the following method:

[0076] The preparation method of the water-reducing agent is basically the same as that in Example 4, except that the ethylene glycol monovinyl polyethylene glycol ether (EPEG-3000) in step A2 is replaced with an equal weight of ethylene glycol monovinyl polyethylene glycol ether (EPEG-2000).

[0077] Comparative Example 6

[0078] The raw material composition and process of the high-performance water-retaining and thickening material for dry-mixed building mortar are basically the same as those in Example 6, except that the water-reducing agent is replaced with an equal weight of water-reducing agent prepared by the following method:

[0079] Add 800 ml DMSO, 100 g methyl acrylate, 20 g ethylene glycol monovinyl polyethylene glycol ether and 50 g acrylic acid to the reactor, stir and mix well, then add 5 g initiator benzoyl peroxide and 3 g chain transfer agent 3-mercaptopropionic acid, heat to 70 °C and react for 5 h, then cool to room temperature, adjust pH to 7 with 30 wt% NaOH solution, and distill under reduced pressure at 60 °C for 2 h to obtain the water-reducing agent.

[0080] Application example: The high-performance water-retaining and thickening material for dry-mixed mortar prepared in the examples and comparative examples is applied to the mortar. The mortar mix proportions are shown in Table 1.

[0081] Table 1 Mortar Mix Proportion Table (kg / m³) 3 )

[0082]

[0083] The materials used in the embodiments and comparative examples of this application are as follows:

[0084] The cement is P.042.5 cement, produced by Lijiang Ancient City Southwest Cement Co., Ltd.

[0085] The main components (by weight) of the high-titanium heavy slag include: 7.67% MgO, 16.7% Al2O3, 24.88% SiO2, 27% CaO, 21.74% TiO2, and 0.34% Fe2O3. It is produced by Panzhihua Huanye Metallurgical Slag Development Co., Ltd.

[0086] The sand used is manufactured sand (medium sand) produced by the Heni Township sand and gravel quarry.

[0087] The main components of fly ash are silicon dioxide (54.9 wt%), aluminum oxide (26.4 wt%), ferric oxide (11.2 wt%), calcium oxide (5.8 wt%), etc., with a particle size uniformly distributed between 0.45-0.85 mm;

[0088] The cellulose ether is hydroxyethyl methyl cellulose, HPMC-2906 type;

[0089] The guar gum, model CMG-5000 (viscosity 5000cps), was purchased from Shanghai Aladdin Biochemical Technology Co., Ltd.

[0090] The sulfonated lignin is designated Borresperse NA with a molecular weight of 8000; the borax is borax pentahydrate.

[0091] The high-performance water-retaining and thickening materials for dry-mixed mortars in the examples and comparative examples were applied to the mortars according to the proportions in Table 1, and the performance of the mortars was tested. The results are shown in Table 2.

[0092] The compressive strength, water retention rate, and consistency loss rate were tested according to the performance indicators of M10 ordinary plastering mortar in GB / T 25181-2019 "Premixed Mortar". The test results are shown in Table 2.

[0093] Table 2 Mortar Performance Indicators

[0094]

[0095] As can be seen from Table 1, the high-performance water-retaining and thickening material for dry-mixed mortar prepared in this application has excellent compressive strength, water retention rate and low consistency loss rate.

[0096] The thickener prepared in this application significantly optimizes the mechanical properties of cement mortar through the synergistic effect of hydrophobic-hydrophilic block copolymers (polycaprolactone (PCL) segments) grafted onto the guar gum backbone and the dynamic crosslinking network of borax. On the one hand, the three-dimensional crosslinking network formed by the hydroxyl groups of guar gum and borax can lock in moisture, ensuring continuous and sufficient hydration of cement particles, reducing unhydrated particles and pores, thereby improving the density of the hardened body. On the other hand, the long-chain alkyl groups in the hydrophobic blocks suppress shrinkage stress by reducing the surface tension of capillary pores, while their micro-regions induce the refinement of ettringite crystals, optimizing pore distribution and reducing structural defects. In addition, the dynamic borax ester bonds provide rigid support in the early stages of hardening, limiting the propagation of microcracks, and ultimately giving the mortar higher compressive strength. The mannose units of the guar gum backbone and the hydroxyl groups at the ends of the graft copolymers strongly bind water molecules through hydrogen bonds, forming a stable hydration layer; at the same time, the micro-regions formed by the hydrophobic segments further delay the moisture loss path by reducing the moisture diffusion rate and increasing the volume occupied by the molecular chains, thereby extending the workability of the mortar and maintaining the fluidity of the slurry. The dynamic reversibility of borate ester bonds allows them to partially break and absorb energy under shear force (shear thinning), and after standing, the bonds recombine and restore viscosity (thixotropic thickening), thus maintaining stable consistency during application.

[0097] The water-reducing agent prepared in this application is based on the synergistic mechanism of sulfonated lignin-grafted polyethylene glycol ether (EPEG-3000)-acrylic acid copolymer, comprehensively optimizing the performance of cement mortar. Its sulfonic acid and carboxyl groups are strongly electronegatively adsorbed onto the surface of cement particles. Through electrostatic repulsion combined with the steric hindrance effect of the long chain of EPEG-3000 (as shown in Table 2, the space available for EPEG-2000 is clearly insufficient), efficient dispersion of cement particles is achieved, reducing the water-cement ratio and promoting hydration, reducing porosity to improve 28-day compressive strength. The polyoxyethylene chain is tightly bound to free water through hydrogen bonds, and the ionization of the carboxyl groups maintains osmotic pressure. Combined with the physical barrier effect of the hydrophobic aromatic ring of sulfonated lignin, a dynamic water-retaining system of "hydrophilic water-locking and hydrophobic slow-release" is constructed, effectively inhibiting water migration to the substrate and environmental evaporation, significantly improving water retention and reducing bleeding. Furthermore, the sulfonic acid groups exhibit salt resistance to Ca2+. 2+ The EPEG side chain provides a continuous steric barrier, and the carboxyl groups dynamically ionize with hydration to compensate for charge decay, which, together with the thickener, helps to maintain the consistency for a long time during application.

[0098] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. However, any modifications, alterations, and variations made by those skilled in the art without departing from the scope of the present invention based on the disclosed technical content are equivalent embodiments of the present invention. Furthermore, any modifications, alterations, and variations made to the above embodiments based on the essential technology of the present invention are still within the protection scope of the present invention.

Claims

1. A high-performance water-retaining and thickening material for dry-mixed building mortar, characterized in that, The ingredients include the following parts by weight: High-titanium heavy slag: 40-60 parts, fly ash: 20-40 parts, bentonite: 10-30 parts, water-reducing agent: 6-8 parts, thickener: 0.5-1.5 parts, early strength agent: 3-6 parts, cellulose ether: 1-3 parts; The thickener is prepared by the following method: S1: ε-caprolactone reacts with 12-hydroxystearic acid to form a copolymer; S2: Guar gum reacts with copolymers to produce modified guar gum; S3: Modified guar gum reacts with borax to produce a thickener; The water-reducing agent is prepared by the following method: A1: Sulfonated lignin reacts with acryloyl chloride to produce modified lignin; A2: Modified lignin reacts with acrylic acid and ethylene glycol monovinyl polyethylene glycol ether to produce a water-reducing agent.

2. The high-performance water-retaining and thickening material for dry-mixed building mortar according to claim 1, characterized in that, In step S1, the mass ratio of ε-caprolactone to 12-hydroxystearic acid is (5-8):

2.

3. The high-performance water-retaining and thickening material for dry-mixed building mortar according to claim 1, characterized in that, In step S2, the mass ratio of guar gum to copolymer is 10:(1-2).

4. The high-performance water-retaining and thickening material for dry-mixed building mortar according to claim 1, characterized in that, In step S3, the mass ratio of modified guar gum to borax is 10:(0.5-1).

5. The high-performance water-retaining and thickening material for dry-mixed building mortar according to claim 1, characterized in that, In step A1, the mass ratio of sulfonated lignin to acryloyl chloride is 1:0.

1.

6. The high-performance water-retaining and thickening material for dry-mixed building mortar according to claim 1, characterized in that, In step A2, the mass ratio of modified lignin to acrylic acid and ethylene glycol monovinyl polyethylene glycol ether is 10:1.5:1.

5.

7. The high-performance water-retaining and thickening material for dry-mixed building mortar according to claim 1, characterized in that, The early strength agent is a mixture of triisopropanolamine, anhydrous calcium sulfoaluminate, and aluminum sulfate.

8. A high-performance water-retaining and thickening material for dry-mixed building mortar according to claim 7, characterized in that, The mass ratio of the triisopropanolamine, anhydrous calcium sulfoaluminate and aluminum sulfate is 1:(1-2):(1-3).

9. A method for preparing a high-performance water-retaining and thickening material for dry-mixed building mortar according to any one of claims 1-8, characterized in that, Includes the following steps: (1) Weigh out the following by weight: high titanium heavy slag: 40-60 parts, fly ash: 20-40 parts, bentonite: 10-30 parts, water reducing agent: 6-8 parts, thickener: 0.5-1.5 parts, early strength agent: 3-6 parts, cellulose ether: 1-3 parts; (2) The high-titanium heavy slag is crushed, dried and ultra-fine ground to obtain high-titanium heavy slag powder; the high-titanium heavy slag powder is mixed with fly ash at high speed to obtain ultra-fine mixed powder. (3) Mix the ultrafine mixed powder with bentonite, water-reducing agent, thickener, early strength agent and cellulose ether evenly to obtain a high-performance water-retaining and thickening material for dry-mixed mortar.

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