A liquid soil stabilizer and its preparation method and application

Abstract

The present invention provides a liquid soil curing agent and its preparation method and application, belonging to the field of soil curing agents. Hydroxypropyl starch ether is introduced and modified with maleic anhydride and 2-acrylic acid, which increases cross-linking sites and side chain network structure, and improves water resistance; secondly, the dispersibility of nano-titanium dioxide is improved by phosphate modification, and in-situ growth is carried out on the surface of graphene oxide, thereby enhancing interfacial binding force; quaternization of polyacrylamide increases ionic bond binding sites, and chitosan grafting improves its biocompatibility and durability; in addition, fluorinated modified bisphenol A epoxy resin introduces C-F bonds, improves acid and alkali resistance, and is blended with SBS to form a microphase separation structure, thereby enhancing toughness. Through the synergistic effect of multiple components, the mechanical properties, durability, corrosion resistance and environmental adaptability of the curing system are significantly improved, ensuring the long-term stability and reliability of the material under complex conditions.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of soil stabilizer, and relates to a liquid soil stabilizer as well as a preparation method and application thereof. BACKGROUND

[0002] Traditional soil stabilizers are usually based on inorganic materials such as cement, lime, and soil binders. Their stabilizing effect mainly relies on chemical reactions and physical adsorption. For example, cement and lime bind to soil particles through hydration reactions, thereby improving the strength and stability of the soil. However, traditional soil stabilizers also have some shortcomings, including environmental impact, brittleness after solidification, limited applicability in certain soil types, and dependence on construction conditions. Therefore, with the advancement of technology and the increasing awareness of environmental protection, researchers have begun to explore more advanced and environmentally friendly liquid soil stabilizers to overcome the shortcomings of traditional methods.

[0003] Liquid soil stabilizers, as an innovative soil improvement material, have received increasing attention in recent years, especially in the fields of urban construction, infrastructure maintenance, and environmental remediation. The core advantage of liquid soil stabilizers lies in their ability to cross-link with soil particles through chemical reactions, thereby improving the compressive strength and stability of the soil. At the same time, they usually have good permeability and fluidity, allowing the stabilizer to be uniformly distributed in the soil, thereby achieving more effective solidification results. In recent years, with the increasing demand for environmentally friendly materials, liquid soil stabilizers based on natural polymer materials have gradually become the focus of research. These materials not only effectively improve soil properties but also reduce negative environmental impacts.

[0004] However, existing liquid soil stabilizers still have shortcomings in terms of durability and adaptability to different soil types. Some stabilizers cannot maintain stable strength after solidification and will decay over time, making it difficult to meet engineering requirements. In addition, many liquid soil stabilizers have strong selectivity for soil when applied, which limits their application range. SUMMARY

[0005] In order to solve the above problems, the present application aims to provide a liquid soil stabilizer and its preparation method and application. In the present application, hydroxypropyl starch ether is introduced and modified with maleic anhydride and 2-acrylic acid. The graft modification of maleic anhydride introduces carboxyl groups and increases crosslinking sites, and the modification of 2-acrylic acid forms a side chain network structure through free radical polymerization to improve its water resistance; the surface of nano titanium dioxide is modified with phosphate to improve the dispersibility of titanium dioxide and introduce phosphate groups, and the in-situ growth on graphene oxide enhances the dispersibility through π-π stacking and enhances the interfacial bonding force; the quaternization of polyacrylamide can increase the ionic bonding sites, and the grafting of chitosan can improve its biocompatibility and durability; and the fluorination modification of bisphenol A epoxy resin can introduce C-F bonds to improve the acid and alkali resistance, and the blending of SBS block copolymer can form a microphase separation structure to improve the toughness of the material. Through the synergistic effect of multiple components, the mechanical properties, durability, corrosion resistance and environmental adaptability of the curing system are significantly improved, ensuring the long-term stability and reliability of the material under complex conditions.

[0006] To achieve this purpose, the present application adopts the following technical solutions:

[0007] In a first aspect, the present application provides a preparation method of a liquid soil stabilizer, which comprises:

[0008] S1: hydroxypropyl starch ether is modified with maleic anhydride and 2-acrylic acid in sequence to obtain modified hydroxypropyl starch ether;

[0009] S2: nano titanium dioxide is modified with phosphate and then compounded with graphene oxide to obtain modified nano titanium dioxide;

[0010] S3: polyacrylamide is modified by quaternization and then grafted with chitosan to obtain modified polyacrylamide;

[0011] S4: bisphenol A type epoxy resin is modified with perfluoroalkyl silane and SBS block copolymer in sequence to obtain a double-modified epoxy resin;

[0012] S5: the modified hydroxypropyl starch ether and the modified polyacrylamide are dispersed in anhydrous ethanol to obtain a mixture E, and the modified nano titanium dioxide, the double-modified epoxy resin and the curing agent are added and uniformly mixed to obtain the liquid soil stabilizer.

[0013] Specifically, S1: dispersing hydroxypropyl starch ether in a methanol aqueous solution to obtain a hydroxypropyl starch ether dispersion, adding maleic anhydride under stirring and adjusting pH with a sodium hydroxide solution to obtain a reaction liquid A, pouring the reaction liquid A into anhydrous ethanol, stirring to precipitate, suction filtering, and vacuum drying to obtain maleic anhydride modified hydroxypropyl starch ether; preparing a maleic anhydride modified hydroxypropyl starch ether solution, adding ammonium persulfate, and adding 2-propenoic acid dropwise under stirring to obtain a reaction liquid B, performing constant temperature reaction, performing vacuum distillation, and performing freeze drying to obtain the modified hydroxypropyl starch ether;

[0014] S2: preparing a nanometer titanium dioxide dispersion, adding trisodium phosphate dodecahydrate, performing constant temperature reaction, centrifuging, washing, and vacuum drying to obtain phosphate modified titanium dioxide; preparing a graphene oxide dispersion, adding phosphate modified titanium dioxide, stirring, centrifuging, and vacuum drying to obtain modified nanometer titanium dioxide;

[0015] S3: preparing a cationic polyacrylamide dispersion, adding 3-chloro-2-hydroxypropyl trimethylammonium chloride, performing constant temperature stirring under nitrogen protection, dialysis, and freeze drying to obtain quaternary ammonium polyacrylamide; dissolving chitosan in a 1% acetic acid solution, adding 1-ethyl-(3-dimethylaminopropyl) carbodiimide hydrochloride and N-hydroxysuccinimide, and activating to obtain a reaction liquid C, preparing a quaternary ammonium polyacrylamide solution, and mixing the quaternary ammonium polyacrylamide solution with the reaction liquid C to obtain a reaction liquid D, performing constant temperature reaction, dialysis, and freeze drying to obtain modified polyacrylamide;

[0016] S4: preparing a bisphenol A type epoxy resin xylene solution, adding 1H, 1H, 2H, 2H-perfluorooctyl triethoxysilane, performing constant temperature reflux, and performing vacuum distillation to obtain fluorinated epoxy resin; melting the fluorinated epoxy resin, adding SBS block copolymer, performing mechanical stirring under nitrogen protection, cooling, and crushing to obtain a double modified epoxy resin;

[0017] S5: adding the modified hydroxypropyl starch ether and the modified polyacrylamide into anhydrous ethanol to obtain a mixture E, adding the modified nanometer titanium dioxide, and ultrasonic dispersing to obtain a mixture F; preheating the double modified epoxy resin, adding OP-10 and a curing agent, stirring to obtain a mixture G, and adding the mixture G into the mixture F to obtain a pretreated soil curing agent, and performing high speed shearing and vacuum degassing to obtain the liquid soil curing agent.

[0018] As a preferred technical solution of the present application, in step S1, the volume ratio of methanol to water in the methanol aqueous solution is 7:3-9:1, for example, can be 7:3, 8:2 or 9:1, but is not limited to the listed values, and other values not listed in the range are also applicable.

[0019] In some alternative embodiments, the mass fraction of the hydroxypropyl starch ether dispersion is 10-15 wt.%, for example, it can be 10 wt.%, 10.5 wt.%, 11 wt.%, 11.5 wt.%, 12 wt.%, 12.5 wt.%, 13 wt.%, 13.5 wt.%, 14 wt.%, or 15 wt.%, but is not limited to the listed values, and other values not listed in the range are also applicable.

[0020] In some alternative embodiments, the amount of maleic anhydride is 3-8% of the mass of the hydroxypropyl starch ether, for example, it can be 3%, 3.5%, 4%, 4.5%, 5%, 5.5%, 6%, 6.5%, 7%, 7.5%, or 8%, but is not limited to the listed values, and other values not listed in the range are also applicable.

[0021] In some alternative embodiments, the concentration of the sodium hydroxide solution is 2-3 M, for example, it can be 2 M, 2.1 M, 2.2 M, 2.3 M, 2.4 M, 2.5 M, 2.6 M, 2.7 M, 2.8 M, 2.9 M, or 3 M, but is not limited to the listed values, and other values not listed in the range are also applicable.

[0022] In some alternative embodiments, the pH is adjusted to 5-6 using a sodium hydroxide solution, for example, it can be 5.0, 5.1, 5.2, 5.3, 5.4, 5.5, 5.6, 5.7, 5.8, 5.9, or 6.0, but is not limited to the listed values, and other values not listed in the range are also applicable.

[0023] In some alternative embodiments, the temperature of the vacuum drying is 70-80°C, for example, it can be 70°C, 71°C, 72°C, 73°C, 74°C, 75°C, 76°C, 77°C, 78°C, 79°C, or 80°C, but is not limited to the listed values, and other values not listed in the range are also applicable.

[0024] In some alternative embodiments, the mass fraction of the maleic anhydride modified hydroxypropyl starch ether solution is 20-30 wt.%, for example, it can be 20 wt.%, 21 wt.%, 22 wt.%, 23 wt.%, 24 wt.%, 25 wt.%, 26 wt.%, 27 wt.%, 28 wt.%, 29 wt.%, or 30 wt.%, but is not limited to the listed values, and other values not listed in the range are also applicable.

[0025] In some optional embodiments, the feeding amount of ammonium persulfate is 0.5-1%, for example, it can be 0.5%, 0.55%, 0.6%, 0.65%, 0.7%, 0.75%, 0.8%, 0.85%, 0.9%, 0.95% or 1%, but is not limited to the listed values, and other values not listed in the range are also applicable.

[0026] In some optional embodiments, the feeding amount of 2-propenoic acid is 5-10%, for example, it can be 5%, 5.5%, 6%, 6.5%, 7%, 7.5%, 8%, 8.5%, 9% or 10%, but is not limited to the listed values, and other values not listed in the range are also applicable.

[0027] In some optional embodiments, the temperature of the constant temperature reaction of the reaction solution B is 45-55°C, for example, it can be 45°C, 46°C, 47°C, 48°C, 49°C, 50°C, 51°C, 52°C, 53°C, 54°C or 55°C, but is not limited to the listed values, and other values not listed in the range are also applicable.

[0028] In some optional embodiments, the time of the constant temperature reaction of the reaction solution B is 3-5h, for example, it can be 3h, 3.2h, 3.4h, 3.6h, 3.8h, 4h, 4.2h, 4.4h, 4.6h, 4.8h or 5h, but is not limited to the listed values, and other values not listed in the range are also applicable.

[0029] As a preferred technical solution of the present application, in step S2, the mass fraction of the nano-titanium dioxide dispersion liquid is 5-10wt.%, for example, it can be 5wt.%, 5.5wt.%, 6wt.%, 6.5wt.%, 7wt.%, 7.5wt.%, 8wt.%, 8.5wt.%, 9wt.% or 10wt.%, but is not limited to the listed values, and other values not listed in the range are also applicable.

[0030] In some optional embodiments, the feeding amount of trisodium phosphate dodecahydrate is 5-10% of the mass of nano-titanium dioxide, for example, it can be 5%, 5.5%, 6%, 6.5%, 7%, 7.5%, 8%, 8.5%, 9% or 10%, but is not limited to the listed values, and other values not listed in the range are also applicable.

[0031] In some optional embodiments, the temperature of the constant temperature reaction is 40-50°C, for example, it can be 40°C, 41°C, 42°C, 43°C, 44°C, 45°C, 46°C, 47°C, 48°C, 49°C or 50°C, but is not limited to the listed values, and other values not listed in the range are also applicable.

[0032] In some optional embodiments, the constant temperature reaction time is 6-8h, for example, it can be 6h, 6.2h, 6.4h, 6.6h, 6.8h, 7h, 7.2h, 7.4h, 7.6h, 7.8h or 8h, but not limited to the listed values, other values not listed in the range are also applicable.

[0033] In some optional embodiments, the mass fraction of the graphene oxide dispersion solution is 0.5-1wt.%, for example, it can be 0.5wt.%, 0.55wt.%, 0.6wt.%, 0.65wt.%, 0.7wt.%, 0.75wt.%, 0.8wt.%, 0.85wt.%, 0.9wt.%, 0.95wt.% or 1wt.%, but not limited to the listed values, other values not listed in the range are also applicable.

[0034] In some optional embodiments, the feeding amount of the graphene oxide is 1-3%, for example, it can be 1%, 1.2%, 1.4%, 1.6%, 1.8%, 2%, 2.2%, 2.4%, 2.6%, 2.8% or 3%, but not limited to the listed values, other values not listed in the range are also applicable.

[0035] In some optional embodiments, the stirring temperature is 60-70℃, for example, it can be 60℃, 61℃, 62℃, 63℃, 64℃, 65℃, 66℃, 67℃, 68℃, 69℃ or 70℃, but not limited to the listed values, other values not listed in the range are also applicable.

[0036] In some optional embodiments, the stirring time is 12-14h, for example, it can be 12h, 12.2h, 12.4h, 12.6h, 12.8h, 13h, 13.2h, 13.4h, 13.6h, 13.8h or 14h, but not limited to the listed values, other values not listed in the range are also applicable.

[0037] As a preferred technical solution of the present application, in step S3, the mass fraction of the cationic polyacrylamide dispersion solution is 10-15wt.%, for example, it can be 10wt.%, 10.5wt.%, 11wt.%, 11.5wt.%, 12wt.%, 12.5wt.%, 13wt.%, 13.5wt.%, 14wt.% or 15wt.%, but not limited to the listed values, other values not listed in the range are also applicable.

[0038] In some optional embodiments, the 3-chloro-2-hydroxypropyltrimethylammonium chloride is fed in an amount of 15-20% by mass of the cationic polyacrylamide, for example, it can be 15%, 15.5%, 16%, 16.5%, 17%, 17.5%, 18%, 18.5%, 19%, or 20%, but is not limited to the listed values, and other values not listed in the range are also applicable.

[0039] In some optional embodiments, the temperature of the constant temperature stirring under nitrogen protection is 50-60°C, for example, it can be 50°C, 51°C, 52°C, 53°C, 54°C, 55°C, 56°C, 57°C, 58°C, 59°C, or 60°C, but is not limited to the listed values, and other values not listed in the range are also applicable.

[0040] In some optional embodiments, the time of the constant temperature stirring under nitrogen protection is 10-12h, for example, it can be 10h, 10.2h, 10.4h, 10.6h, 10.8h, 11h, 11.2h, 11.4h, 11.6h, 11.8h, or 12h, but is not limited to the listed values, and other values not listed in the range are also applicable.

[0041] In some optional embodiments, the mass fraction of the chitosan in the acetic acid solution is 1-1.5wt.%, for example, it can be 1wt.%, 1.05wt.%, 1.1wt.%, 1.15wt.%, 1.2wt.%, 1.25wt.%, 1.3wt.%, 1.35wt.%, 1.4wt.%, 1.45wt.%, or 1.5wt.%, but is not limited to the listed values, and other values not listed in the range are also applicable.

[0042] In some optional embodiments, the mass ratio of the 1-ethyl-(3-dimethylaminopropyl) carbodiimide hydrochloride to the chitosan is 1-1.5:1, for example, it can be 1:1, 1.05:1, 1.1:1, 1.15:1, 1.2:1, 1.25:1, 1.3:1, 1.35:1, 1.4:1, 1.45:1, or 1.5:1, but is not limited to the listed values, and other values not listed in the range are also applicable.

[0043] In some optional embodiments, the mass ratio of the N-hydroxysuccinimide to the chitosan is 1-1.5:1, for example, it can be 1:1, 1.05:1, 1.1:1, 1.15:1, 1.2:1, 1.25:1, 1.3:1, 1.35:1, 1.4:1, 1.45:1, or 1.5:1, but is not limited to the listed values, and other values not listed in the range are also applicable.

[0044] In some optional embodiments, the activation time is 2-3h, for example, it can be 2h, 2.1h, 2.2h, 2.3h, 2.4h, 2.5h, 2.6h, 2.7h, 2.8h, 2.9h or 3h, but not only limited to the listed values, other values not listed in the range are also applicable.

[0045] In some optional embodiments, the mass fraction of the quaternary ammonium polyacrylamide dispersion is 15-20wt.%, for example, it can be 15wt.%, 15.5wt.%, 16wt.%, 16.5wt.%, 17wt.%, 17.5wt.%, 18wt.%, 18.5wt.%, 19wt.%, 19.5wt.% or 20wt.%, but not only limited to the listed values, other values not listed in the range are also applicable.

[0046] In some optional embodiments, the amount of chitosan is 3-6% of the mass of quaternary ammonium polyacrylamide, for example, it can be 3%, 3.3%, 3.6%, 3.9%, 4.2%, 4.5%, 4.8%, 5%, 5.3%, 5.6% or 6%, but not only limited to the listed values, other values not listed in the range are also applicable.

[0047] In some optional embodiments, the temperature of the constant temperature reaction of the reaction solution D is 35-45℃, for example, it can be 35℃, 36℃, 37℃, 38℃, 39℃, 40℃, 41℃, 42℃, 43℃, 44℃ or 45℃, but not only limited to the listed values, other values not listed in the range are also applicable.

[0048] In some optional embodiments, the time of the constant temperature reaction of the reaction solution D is 12-16h, for example, it can be 12h, 12.4h, 12.8h, 13.2h, 13.6h, 14h, 14.4h, 14.8h, 15.2h, 15.6h or 16h, but not only limited to the listed values, other values not listed in the range are also applicable.

[0049] As a preferred technical solution of the present application, in step S4, the mass fraction of the bisphenol A type epoxy resin xylene solution is 25-35wt.%, for example, it can be 25wt.%, 26wt.%, 27wt.%, 28wt.%, 29wt.%, 30wt.%, 31wt.%, 32wt.%, 33wt.%, 34wt.% or 35wt.%, but not only limited to the listed values, other values not listed in the range are also applicable.

[0050] In some optional embodiments, the 1H, 1H, 2H, 2H-perfluorooctyltriethoxysilane is used in an amount of 5-6% by mass of the bisphenol A type epoxy resin, for example, can be 5%, 5.1%, 5.2%, 5.3%, 5.4%, 5.5%, 5.6%, 5.7%, 5.8%, 5.9% or 6%, but not only limited to the listed values, other values not listed in the range of values are also applicable.

[0051] In some optional embodiments, the temperature of the constant temperature reflux reaction is 70-80℃, for example, can be 70℃, 71℃, 72℃, 73℃, 74℃, 75℃, 76℃, 77℃, 78℃, 79℃ or 80℃, but not only limited to the listed values, other values not listed in the range of values are also applicable.

[0052] In some optional embodiments, the time of the constant temperature reflux reaction is 3-4h, for example, can be 3h, 3.1h, 3.2h, 3.3h, 3.4h, 3.5h, 3.6h, 3.7h, 3.8h, 3.9h or 4h, but not only limited to the listed values, other values not listed in the range of values are also applicable.

[0053] In some optional embodiments, the SBS block copolymer is used in an amount of 5-8% by mass of the fluorinated epoxy resin, for example, can be 5%, 5.3%, 5.6%, 5.9%, 6.2%, 6.5%, 6.8%, 7.1%, 7.4%, 7.7% or 8%, but not only limited to the listed values, other values not listed in the range of values are also applicable.

[0054] In some optional embodiments, the rotation speed of the mechanical stirring under nitrogen protection is 500-600rpm, for example, can be 500rpm, 510rpm, 520rpm, 530rpm, 540rpm, 550rpm, 560rpm, 570rpm, 580rpm, 590rpm or 600rpm, but not only limited to the listed values, other values not listed in the range of values are also applicable.

[0055] In some optional embodiments, the time of the mechanical stirring under nitrogen protection is 2-3h, for example, can be 2h, 2.1h, 2.2h, 2.3h, 2.4h, 2.5h, 2.6h, 2.7h, 2.8h, 2.9h or 3h, but not only limited to the listed values, other values not listed in the range of values are also applicable.

[0056] As a preferred technical solution of the present application, in step S5, in some optional embodiments, the total solid content of the mixture E is 20-30 wt.%, for example, it can be 20 wt.%, 21 wt.%, 22 wt.%, 23 wt.%, 24 wt.%, 25 wt.%, 26 wt.%, 27 wt.%, 28 wt.%, 29 wt.%, or 30 wt.%, but not limited to the listed values, other values not listed in this range are also applicable.

[0057] In some optional embodiments, the preheating temperature of the double-modified epoxy resin is 45-50℃, for example, it can be 45℃, 45.5℃, 46℃, 46.5℃, 47℃, 47.5℃, 48℃, 48.5℃, 49℃, or 50℃, but not limited to the listed values, other values not listed in this range are also applicable.

[0058] In some optional embodiments, the amount of OP-10 added is 3-5% of the mass of the epoxy resin, for example, it can be 3%, 3.2%, 3.4%, 3.6%, 3.8%, 4%, 4.2%, 4.4%, 4.6%, 4.8%, or 5%, but not limited to the listed values, other values not listed in this range are also applicable.

[0059] The amount of curing agent added is 10-15% of the mass of the epoxy resin, for example, it can be 10%, 10.5%, 11%, 11.5%, 12%, 12.5%, 13%, 13.5%, 14%, 14.5%, or 15%, but not limited to the listed values, other values not listed in this range are also applicable.

[0060] In some optional embodiments, the rotational speed of the high-speed shearing of the pretreated soil curing agent is 3000-5000 rpm, for example, it can be 3000 rpm, 3200 rpm, 3400 rpm, 3600 rpm, 3800 rpm, 4000 rpm, 4200 rpm, 4400 rpm, 4600 rpm, 4800 rpm, or 5000 rpm, but not limited to the listed values, other values not listed in this range are also applicable.

[0061] In some optional embodiments, the time of high-speed shearing of the pretreated soil curing agent is 10-20 min, for example, it can be 10 min, 11 min, 12 min, 13 min, 14 min, 15 min, 16 min, 17 min, 18 min, 19 min, or 20 min, but not limited to the listed values, other values not listed in this range are also applicable.

[0062] In some optional embodiments, the time for vacuum degassing is 20-30 min, for example, it can be 20 min, 21 min, 22 min, 23 min, 24 min, 25 min, 26 min, 27 min, 28 min, 29 min or 30 min, but not limited to the listed values, and other values not listed in the range are also applicable.

[0063] In a second aspect, the present application provides a liquid soil stabilizer, which comprises the following components by mass fraction:

[0064]

[0065] In some optional embodiments, the mass fraction of the modified hydroxypropyl starch ether is 40-45 parts, for example, it can be 40 parts, 40.5 parts, 41 parts, 41.5 parts, 42 parts, 42.5 parts, 43 parts, 43.5 parts, 44 parts or 45 parts, but not limited to the listed values, and other values not listed in the range are also applicable.

[0066] In some optional embodiments, the mass fraction of the modified nano-titanium dioxide is 2-5 parts, for example, it can be 2 parts, 2.5 parts, 3 parts, 3.5 parts, 4 parts or 5 parts, but not limited to the listed values, and other values not listed in the range are also applicable.

[0067] In some optional embodiments, the mass fraction of the modified polyacrylamide is 20-25 parts, for example, it can be 20 parts, 20.5 parts, 21 parts, 21.5 parts, 22 parts, 22.5 parts, 23 parts, 23.5 parts, 24 parts or 25 parts, but not limited to the listed values, and other values not listed in the range are also applicable.

[0068] In some optional embodiments, the mass fraction of the double-modified epoxy resin is 30-35 parts, for example, it can be 30 parts, 30.5 parts, 31 parts, 31.5 parts, 32 parts, 32.5 parts, 33 parts, 33.5 parts, 34 parts or 35 parts, but not limited to the listed values, and other values not listed in the range are also applicable.

[0069] In the present application, hydroxypropyl starch ether is introduced, which is a polysaccharide derivative obtained by hydroxypropylation modification of natural starch. Its molecular structure contains a large number of hydroxyl and ether groups, which endow hydroxypropyl starch ether with excellent hydrophilicity and water solubility. Specifically, the hydroxyl groups in the molecule can interact with water molecules through hydrogen bonds, thereby enhancing their solubility and dispersibility in water. This property enables hydroxypropyl starch ether to be uniformly distributed in aqueous solution, forming a stable solution, which is crucial for subsequent application in the preparation of soil stabilizer.

[0070] Furthermore, the introduction of hydroxypropyl substituent groups disrupts some of the intermolecular and intramolecular hydrogen bonding in the native starch molecule chain. This property results in a significant improvement in its dispersibility in water, enabling it to form a uniform dispersion system, which is of great significance to improving the effect of the solidifying agent. In particular, in soil solidification applications, hydroxypropyl starch ether can form a high-molecular polymer network with adhesion through its good thickening and film-forming properties, thereby enhancing the binding force of soil particles. The stretching of the molecular chain in aqueous solution enables it to form a high-molecular viscous network, playing a preliminary physical crosslinking role, improving the initial coagulation ability of the soil solidifying agent, and thus providing a basis for subsequent solidification and reinforcement.

[0071] Maleic anhydride-modified hydroxypropyl starch ether is introduced. The anhydride group in the maleic anhydride molecule is a highly active functional group that can undergo esterification or ring-opening addition reactions with the hydroxyl groups in the hydroxypropyl starch ether molecule, forming a chemical structure containing double bonds and carboxyl groups. This reaction not only enhances the chemical reactivity of the modified starch ether, but also imparts it with stronger polarity. This structural change enables the modified hydroxypropyl starch ether to have more reaction sites, providing a more stable interfacial action for binding with soil particles.

[0072] Through the introduction of maleic anhydride, the newly added double bond structure and carboxyl groups on the molecular chain of the modified hydroxypropyl starch ether can significantly improve its chemical stability, especially in different environmental conditions (such as in acidic or alkaline environments). These structures not only enhance the chemical activity of the material, but also enable it to maintain better stability in extreme soil environments. Due to the introduction of double bonds, the modified starch ether can act as active sites in subsequent free radical polymerization reactions with monomers such as 2-acrylic acid, thereby forming a three-dimensional crosslinked network structure. The formation of this network further improves the water resistance and mechanical properties of the solidifying agent.

[0073] Under the initiation of ammonium persulfate, 2-acrylic acid undergoes chain growth reactions with the double bonds in the maleic anhydride-modified hydroxypropyl starch ether through free radical polymerization, forming a three-dimensional crosslinked network containing side chain structures. This crosslinked network not only improves the water resistance, mechanical properties, and chemical stability of the modified starch ether, but also significantly improves its compatibility and dispersion performance with other components. Through structural modification of the crosslinked network, the modified starch ether can better adapt to complex soil solidification environments and enhance the overall effect of the soil solidifying agent.

[0074] In addition, the carboxyl groups provided by the acrylic monomers in the polymerization reaction can form hydrogen bonds or electrostatic interactions with the polar or charged groups in the soil particles, further enhancing the polarity and interfacial binding capacity of the solidifying agent. Through this interaction, the modified starch ether can be firmly attached to the surface of the soil particles, improving the dispersibility and binding force of the solidifying agent in the soil. This makes the soil solidifying agent exhibit better durability, stability and adaptability in complex soil environments, especially in environments with large changes in acidity and alkalinity.

[0075] In the present application, nano-titanium dioxide is introduced as a filler. Nano-titanium dioxide has a unique crystal structure and significantly enhanced physical and chemical properties at the nanoscale. In particular, its high specific surface area and surface energy exhibit excellent reactivity and high adsorption at the nanoscale, making nano-titanium dioxide an ideal filler. Its surface contains a certain amount of hydroxyl groups, which not only enhance its hydrophilicity but also provide abundant active sites, helping to form stronger chemical bonds with other organic components. In this way, nano-titanium dioxide can effectively bind with the organic polymer network, enhancing its performance and significantly improving the compressive strength, durability and mechanical properties of the solidifying agent.

[0076] As an inorganic filler, nano-titanium dioxide can uniformly embed in the three-dimensional network structure of organic polymers, enhancing the mechanical strength and chemical corrosion resistance of the material. In addition, its high specific surface area and excellent adsorption capacity can also enhance the binding force of the solidifying agent with soil particles, thereby improving the overall structure and strength of the soil, making it exhibit more excellent performance in the soil solidification process. The use of nano-titanium dioxide filler in the solidifying agent can effectively improve the physical properties of the soil, increase its compressive and tensile strength, and enhance the durability of the solidifying agent.

[0077] To further enhance the performance of nano-titanium dioxide, the present application uses phosphate to modify it. By introducing trisodium phosphate, the phosphate group reacts with the hydroxyl groups on the surface of nano-titanium dioxide to form a phosphate layer, and part of the Ti-O-P coordination bond structure is formed. This reaction significantly improves the surface energy and chemical stability of nano-titanium dioxide; the introduction of the phosphate layer not only enhances its surface hydrophilicity but also improves its compatibility with other components, making the modified nano-titanium dioxide have better durability and chemical stability in various complex environments.

[0078] The introduction of phosphate groups further improves the interfacial bonding ability of nano-titanium dioxide with other organic components such as hydroxypropyl starch ether, polyacrylamide, etc. In soil stabilizer applications, phosphate groups can interact with these components, promoting inter-particle interactions, enhancing their physical cross-linking and chemical bonding strength. This phosphate modification not only improves the chemical stability of the material, but also makes it more resistant to corrosion and stable in acidic and alkaline environments, greatly improving the adaptability and reliability of the soil stabilizer in complex environments.

[0079] Furthermore, the phosphate-modified nano-titanium dioxide grows in situ on graphene oxide. Graphene oxide has a unique two-dimensional sheet structure, providing a larger specific surface area, allowing it to disperse more uniformly in the matrix. The introduction of graphene oxide can further improve the dispersibility of nano-titanium dioxide in the polymer matrix, thereby optimizing the mechanical properties and thermal stability of the stabilizer. The abundant oxygen-containing functional groups on the surface of graphene oxide enable it to form various interactions with phosphate-modified titanium dioxide and other components with polarity or charge, such as quaternary ammonium polyacrylamide, such as hydrogen bonding, electrostatic interaction or coordination. These interactions not only significantly improve the interfacial bonding strength of the material, but also enhance the mechanical properties and chemical stability of the material.

[0080] The π-π stacking interaction and surface chemical reaction between graphene oxide and nano-titanium dioxide also contribute to the formation of a tight interfacial bond, which ensures the formation of a more stable composite material. As a two-dimensional material, graphene oxide plays an important role in enhancing the mechanical properties, thermal stability and compression resistance of the composite material. At the same time, the introduction of graphene oxide also enables the modified stabilizer to maintain good structural stability and long-term performance when faced with extreme environments.

[0081] Cationic polyacrylamide is a high molecular weight material copolymerized from acrylamide and cationic monomers, containing positively charged cationic functional groups in its molecular chain. Due to the presence of these cationic functional groups, cationic polyacrylamide can bind to the surface of negatively charged soil particles through electrostatic adsorption, significantly improving its adsorption capacity and binding strength to soil particles. This property makes cationic polyacrylamide have very important application potential in soil stabilization and improvement of soil structure.

[0082] The molecular chain of cationic polyacrylamide has strong tensile properties and high chemical stability, and can form a three-dimensional network structure through cross-linking or hydrogen bonding, which further enhances its physical binding force with soil particles. Due to its flexibility and hydrophilicity, cationic polyacrylamide not only improves the rheological properties of the solidifying agent, making it have better solubility and fluidity in aqueous solution, but also promotes the uniform dispersion and deep penetration of the solidifying agent in the soil. This feature is crucial for the construction process of soil solidifying agent, which helps to ensure that the solidifying agent can effectively cover the soil surface and have stronger combination with soil particles, thereby improving the solidifying effect.

[0083] By introducing 3-chloro-2-hydroxypropyl trimethyl ammonium chloride to modify cationic polyacrylamide, the cationic density and interaction with soil particles can be significantly enhanced. 3-chloro-2-hydroxypropyl trimethyl ammonium chloride is a cationic chemical reagent, which reacts with the amine group in the polyacrylamide molecular chain through nucleophilic substitution reaction to form a quaternary ammonium salt structure. The quaternized polyacrylamide molecular chain has higher cationic density, which can form a stable complex interface with negatively charged soil particles, graphene oxide, phosphate groups and other polar components through electrostatic interaction. The introduction of quaternary ammonium salt structure also makes polyacrylamide have stronger antibacterial performance, which can effectively inhibit the growth of microorganisms, thereby prolonging the service life of soil solidifying agent.

[0084] In addition, the electrostatic interaction in the quaternized polyacrylamide molecular chain is also enhanced, which helps to improve its durability and anti-aging performance. In soil solidifying agent application, this enhanced electrostatic interaction not only improves the binding strength between the soil solidifying agent and the soil particles, but also enhances the stability and reliability of the soil solidifying agent in harsh environments. Therefore, the performance of cationic polyacrylamide modified by quaternization is significantly improved in soil solidifying agent, showing better durability, antibacterial property and stability in complex soil environment.

[0085] In order to further improve the performance of cationic polyacrylamide, the present application introduces chitosan for modification. As a natural polysaccharide, chitosan has good biocompatibility and antibacterial property, and its molecule contains rich amino groups which can react with the functional groups in the quaternized polyacrylamide molecular chain to form a covalently bonded network structure. The introduction of chitosan not only enhances the biodegradability and environmental friendliness of polyacrylamide, but also improves the mechanical properties of the system through interaction with the polyacrylamide molecular chain. Through this covalently bonded network structure, chitosan can effectively enhance the structural stability of cationic polyacrylamide, thereby improving the compressive strength and durability of the solidifying agent.

[0086] Chitosan not only improves the mechanical properties of polyacrylamide, but also enhances its adaptability in complex soil environments. Due to the introduction of chitosan, the modified cationic polyacrylamide can provide better particle bonding force during soil solidification, making the soil more compact and enhancing its compression and tensile resistance. In addition, the biocompatibility and antibacterial properties of chitosan can effectively inhibit the growth of harmful microorganisms during long-term application, further improving the durability and stability of soil solidifying agent.

[0087] In the present invention, bisphenol A type epoxy resin is introduced, which contains epoxy groups and benzene ring structure in its molecule, giving it unique properties. Epoxy groups are a kind of functional group with high reactivity, which can react with other reactive groups to form cross-linked structure, improving the overall strength and durability of the material. The high reactivity of epoxy groups not only increases the bonding force between the resin and other components, but also promotes the cross-linking degree of the resin, thereby improving the mechanical properties, thermal stability and chemical resistance of the cured material. On the other hand, the introduction of benzene ring structure enhances the rigidity and chemical stability of epoxy resin, making it maintain good heat resistance and anti-aging ability under high temperature and extreme environmental conditions. These characteristics make bisphenol A type epoxy resin have wide applicability in application fields requiring high strength, corrosion resistance and high temperature resistance.

[0088] The high cross-linking density structure formed after the reaction of epoxy resin makes the material have excellent chemical corrosion resistance and mechanical properties. Through cross-linking reaction, the structure between molecular chains is more compact, forming a stable network structure. This high cross-linking degree structure not only improves the mechanical properties such as impact resistance, shear resistance, pressure resistance of the material, but also effectively enhances its resistance to external chemicals. For example, when epoxy resin contacts acid or alkali solution, its cross-linked network can effectively prevent the penetration of corrosive substances, thereby prolonging the service life of the material.

[0089] In order to further enhance the acid and alkali resistance and durability of epoxy resin, 1H, 1H, 2H, 2H-perfluorooctyltriethoxysilane is introduced to modify bisphenol A type epoxy resin. The introduction of this chemical modifier introduces C-F bond structure into the epoxy resin molecule. C-F bond is a chemical bond with very high bond energy, which has very strong chemical stability, so that the epoxy resin shows excellent corrosion resistance when it faces acid and alkali medium, oxidizing agent, solvent and other harsh environments. C-F bond not only can significantly improve the acid and alkali resistance of epoxy resin, but also can enhance its aging resistance and high temperature resistance, especially in long-term use or exposure to extreme conditions, the modified epoxy resin can maintain longer service life.

[0090] In addition, the fluorination modification also greatly reduces the surface energy of the material, making it exhibit excellent water resistance and stain resistance. This reduction in surface energy makes the modified epoxy resin surface hydrophobic, effectively preventing the penetration or adhesion of liquids such as water and oil, thereby further improving its reliability in humid environments. Whether exposed to a humid environment for a long time or used in waterproof and moisture-proof applications, fluorinated modified epoxy resin can provide better protection.

[0091] Through blending with SBS block copolymer, the modified epoxy resin forms a microphase separation structure. The SBS block copolymer contains flexible and hard polymer segments, which undergo phase separation in the epoxy resin matrix to form a microstructure with independent phases. Specifically, the flexible polymer segments in SBS form an independent flexible phase in the epoxy resin matrix, while the hard epoxy resin retains its rigidity and strength. This microphase separation structure endows the material with excellent comprehensive performance, i.e., the material has both good toughness and sufficient mechanical strength. The presence of flexible phase enhances the ductility of the material, making it less prone to cracking under external force impact, while the hard phase provides higher compressive and tensile strength, enabling the material to withstand greater loads.

[0092] This microphase separation structure makes the modified epoxy resin have excellent mechanical properties while maintaining flexibility and impact resistance, making it particularly suitable for complex soil solidification environments. In these environments, soil solidification agents need to cope with geological vibrations, water penetration, temperature fluctuations, and other challenges. The modified epoxy resin, through its special microphase separation structure, not only improves the durability of the material, but also enhances its stability and reliability under different environmental conditions.

[0093] The synergistic effect between these components effectively solves the problem of strength decay: the carboxyl groups in the maleic anhydride modified starch ether molecules and the quaternary ammonium groups in the quaternized PAM molecules form a stable ionic bond network through ion exchange reaction, which significantly enhances the mechanical strength and durability of the solidification system. The formation of ionic bonds not only increases the interaction force between molecular chains, but also effectively improves the overall structure of the material, making it more stable under external force; the active side chains formed by free radical polymerization during acrylic acid graft modification can react with epoxy groups in epoxy resin to form a covalent crosslinking network with higher strength. This covalent crosslinking structure greatly enhances the strength and chemical resistance of the solidification system. During crosslinking, active side chains can form strong chemical bonds with epoxy groups, thereby improving the durability and crack resistance of the material.

[0094] The chitosan reacts with the epoxy groups in the epoxy resin molecules through its amino groups, further strengthening the cross-linking degree of the network and forming a three-dimensional interpenetrating structure. This multiple cross-linking network structure can provide more stress transfer paths for the material. Under stress conditions, the stress of the material can be shared in multiple cross-linking networks, thereby improving the toughness and impact resistance of the structure. When some of the cross-linking bonds break, other cross-linking networks can take over the function of the broken part, ensuring the overall strength and stability of the material, thereby significantly improving the stability and durability of the cured system under long-term load.

[0095] The phosphoric acid groups bind with the hydroxyl groups in the starch ether molecules through hydrogen bonding, enhancing the interfacial compatibility between the two and improving the interfacial bonding force, thereby improving the structural stability and long-term durability of the cured system. The hydrogen bonding between the phosphoric acid groups and the hydroxyl groups not only enhances their mutual adsorption, but also makes the system exhibit better corrosion resistance in a humid environment, further improving the adaptability of the material in complex environments.

[0096] The two-dimensional structure of graphene oxide enables it to form strong interfacial interactions with surrounding organic molecules through π-π stacking, which significantly enhances the interfacial bonding force, prevents interfacial peeling, and improves the overall mechanical properties and durability of the composite material. The unique structure and chemical properties of graphene oxide make it play an important role in enhancing the composite material, especially in applications requiring high structural stability.

[0097] The organic silicon groups interact with the starch ether, polyacrylamide, and epoxy resin molecules through chemical bonds, further enhancing the interfacial bonding strength and improving the interfacial stability of the composite material. The introduction of organic silicon groups not only improves the interfacial affinity but also enhances the water vapor barrier ability of the material, which helps to improve the environmental resistance of the composite material.

[0098] The block copolymer forms a microphase separation structure with alternating flexible and rigid phases in the curing agent, which effectively optimizes the stress dispersion performance. The flexible phase can absorb and relieve external stress, while the rigid phase provides the required strength of the material; the high specific surface area and uniform distribution of nano-titanium dioxide can prevent crack propagation and provide effective stress dispersion paths, while also improving the mechanical properties of the material and enhancing its wear resistance and crack resistance; the conductive network formed by graphene oxide and polyacrylamide molecules helps to improve the mechanical properties and dispersion toughness of the material, thereby effectively extending the service life of the material. This optimized microstructure provides a stress dispersion mechanism, prevents crack propagation, improves the toughness of the material, and ensures the stability and reliability of the composite material during long-term use.

[0099] At the same time, there is also a synergistic effect of solving the poor acid and alkali resistance of the curing agent: after fluorinated modification of bisphenol A type epoxy resin, the C-F bond introduced in the molecule has high bond energy and chemical stability, so that the material exhibits excellent corrosion resistance in acid and alkali medium, reducing the damage of acid and alkali environment to the material structure. The high chemical stability of C-F bond makes the modified epoxy resin have strong resistance to acid and alkali medium, significantly improving the stability of the material in acidic or alkaline environment.

[0100] The organic silicon group improves the hydrophobicity of the material surface, reduces the affinity of the surface to acid and alkali solution, thereby reducing the penetration of acid and alkali solution and improving the acid and alkali resistance of the material. The introduction of organic silicon group forms a hydrophobic protective layer on the surface of the material, which not only effectively prevents the penetration of water, but also reduces the penetration rate of acid and alkali solution, further enhancing the durability and stability of the material.

[0101] The photocatalytic performance of titanium dioxide can decompose harmful substances in the air under ultraviolet light irradiation, and help to decompose erosive organic substances in acid and alkali environment, further protecting the material structure from chemical corrosion. Titanium dioxide not only has the ability to catalytically degrade harmful substances under ultraviolet light irradiation, but also can decompose erosive substances through redox reaction in acid and alkali environment, reduce the damage of acid and alkali to the material and prolong its service life.

[0102] The cationic group in the quaternary ammonium polyacrylamide molecule can interact with hydrogen ions or hydroxide ions in the acid and alkali medium to adjust the local pH value, thereby maintaining the acid and alkali stability of the system. This adjustment enables the material to maintain a relatively stable internal environment in acid and alkali environment, avoiding excessive interference of acid and alkali on the performance of the material, and improving the corrosion resistance and durability of the material.

[0103] The phosphate groups in the phosphate modified layer can react with hydrogen ions or hydroxide ions in the external acid and alkali substances, thereby effectively neutralizing the external acid and alkali substances. The phosphate groups react with the ions in the acid and alkali substances to play a buffering and neutralizing role, helping the material resist the erosion of acid and alkali and maintaining the chemical stability and structural integrity of the material.

[0104] The amino group in chitosan can react with hydrogen ions or hydroxide ions in the external acid and alkali medium to provide proton buffering effect, thereby stabilizing the pH of the system and avoiding excessive acid and alkali effect to damage the material structure. The amino group of chitosan reacts with external acid and alkali substances in acid and alkali environment to provide proton buffering function, ensuring that the material can maintain good chemical stability under the action of external acid and alkali substances, further enhancing the durability of the material.

[0105] In a third aspect, the application provides a liquid soil stabilizer for use in building foundation.

[0106] Compared with the prior art, the application has the following beneficial effects:

[0107] (1) The application introduces maleic anhydride modified hydroxypropyl starch ether, the polarity group and chemical activity of which enhances the binding force with soil particles, and the introduction of 2-acrylic acid forms a three-dimensional cross-linked network, which significantly improves the water resistance, mechanical properties and environmental adaptability of the soil stabilizer, thereby optimizing the soil stabilization effect;

[0108] (2) The modification of nano-titanium dioxide by phosphate and the in-situ growth of graphene oxide on the surface of the nano-titanium dioxide significantly enhance the dispersibility, interfacial binding force and chemical stability of the material, thereby optimizing the mechanical properties, durability, adaptability and reliability of the soil stabilizer in complex environments;

[0109] (3) The application modifies cationic polyacrylamide by 3-chloro-2-hydroxypropyl trimethyl ammonium chloride and chitosan, which significantly improves the cationic density, antibacterial property and durability of the cationic polyacrylamide, forms an enhanced network structure and binding force with soil particles, thereby optimizing the compressive strength, durability, stability and adaptability of the soil stabilizer in complex environments;

[0110] (4) The application introduces bisphenol A type epoxy resin and performs fluorination modification and SBS blending to form a micro-phase separation structure, which significantly improves the mechanical properties, corrosion resistance, high temperature resistance and impact resistance of the material, and is particularly suitable for high-strength applications in complex environments;

[0111] (5) Through the synergistic effect of multiple components, the application combines multiple cross-linked networks, interfacial reinforcement mechanisms and acid and alkali resistance modifications, which significantly improves the mechanical properties, durability, corrosion resistance and environmental adaptability of the stabilization system, and ensures the long-term stability and reliability of the material in complex conditions;

[0112] (6) The use of renewable bio-based materials and low-toxicity inorganic fillers reduces the dependence on non-renewable resources. Secondly, the modification process mostly uses low-pollution green chemical processes, which reduces the environmental burden. At the same time, the stabilizer can be gradually degraded after application, and its products are non-toxic and harmless, avoiding adverse effects on the soil ecology. BRIEF DESCRIPTION OF DRAWINGS

[0113] Figure 1 The high-resolution transmission electron microscope image of the modified nano-titanium dioxide provided for Example 1 of the application (scale: 50 nm);

[0114] Figure 2 The high-resolution transmission electron microscope image of the modified nano-titanium dioxide provided for Example 1 of the application (scale: 20 nm). DETAILED DESCRIPTION

[0115] The technical solutions of the present application will be described in detail below with reference to specific embodiments and drawings. The embodiments described herein are specific embodiments of the present application, which are used to illustrate the concept of the present application; these descriptions are all explanatory and exemplary, and should not be understood as limiting the embodiments of the present application and the protection scope of the present application. In addition to the embodiments described herein, those skilled in the art can also employ other technical solutions that are obvious based on the content disclosed in the claims and the description of the present application, which include technical solutions that make any obvious substitutions and modifications to the embodiments described herein.

[0116] The chemical reagents used in the embodiments and comparative examples of the present application are all commercially available products without further purification or treatment.

[0117] Embodiment 1

[0118] The present embodiment provides a liquid soil stabilizer and a preparation method thereof, wherein the liquid soil stabilizer comprises the following components by mass fraction:

[0119]

[0120] The preparation method specifically comprises the following steps:

[0121] S1: The hydroxypropyl starch ether is modified with maleic anhydride and 2-acrylic acid in sequence to obtain a modified hydroxypropyl starch ether;

[0122] Specifically, the hydroxypropyl starch ether is dispersed in a methanol aqueous solution with a volume ratio of methanol to water of 7:3 to obtain a hydroxypropyl starch ether dispersion with a mass fraction of 10wt.%, and under stirring, maleic anhydride with a dosage of 5% of the mass of the hydroxypropyl starch ether is added and the pH is adjusted to 5 with a 2M sodium hydroxide solution to obtain a reaction liquid A, the reaction liquid A is poured into anhydrous ethanol, stirred and precipitated, filtered, and vacuum dried at 72℃ to obtain a maleic anhydride modified hydroxypropyl starch ether; a 25wt.% maleic anhydride modified hydroxypropyl starch ether solution is prepared, and ammonium persulfate with a dosage of 0.75% of the mass of the maleic anhydride modified hydroxypropyl starch ether is added, and 2-acrylic acid with a dosage of 5% of the mass of the maleic anhydride modified hydroxypropyl starch ether is added dropwise under stirring to obtain a reaction liquid B, which is reacted at 50℃ for 4h, then distilled under reduced pressure and freeze-dried to obtain a modified hydroxypropyl starch ether;

[0123] S2: The nano-titanium dioxide is modified with phosphates and then compounded with graphene oxide to obtain a modified nano-titanium dioxide;

[0124] Specifically, a nano-titanium dioxide dispersion solution with a mass fraction of 8wt.% is prepared, 5% of the mass of the nano-titanium dioxide is added as trisodium phosphate dodecahydrate, and after reaction at a constant temperature of 45°C for 8h, centrifugal separation, washing, and vacuum drying, phosphate-modified titanium dioxide is obtained; a graphene oxide dispersion solution with a mass fraction of 0.5wt.% is prepared, and the phosphate-modified titanium dioxide is added, wherein the amount of graphene oxide added is 2.3% of the mass of the phosphate-modified titanium dioxide, and after stirring at 64°C for 13h, centrifugal separation, and vacuum drying, modified nano-titanium dioxide is obtained; Figure 1 、 Figure 2 For the high-resolution transmission electron microscopy images of the modified nano-titanium dioxide at different scales, it can be observed that the titanium dioxide is in situ grown on the surface of the graphene oxide.

[0125] S3: After the polyacrylamide is modified by quaternization, graft copolymerization is performed with chitosan to obtain modified polyacrylamide;

[0126] Specifically, a cationic polyacrylamide dispersion solution with a mass fraction of 10wt.% is prepared, 15% of the mass of the cationic polyacrylamide is added as 3-chloro-2-hydroxypropyltrimethylammonium chloride, and after stirring at a constant temperature of 55°C for 10h under nitrogen protection, dialysis, and freeze-drying, quaternary ammonium polyacrylamide is obtained; chitosan is dissolved in a 1% acetic acid solution, the mass fraction of chitosan in the acetic acid solution is 1.2wt.%, and 1-ethyl-(3-dimethylaminopropyl) carbodiimide hydrochloride and N-hydroxysuccinimide are added and activated for 2h to obtain reaction solution C, wherein the mass ratio of 1-ethyl-(3-dimethylaminopropyl) carbodiimide hydrochloride to chitosan is 1:1, and the mass ratio of N-hydroxysuccinimide to chitosan is 1.5:1; quaternary ammonium polyacrylamide solution is prepared and mixed with reaction solution C to obtain reaction solution D, wherein the amount of chitosan added is 6% of the mass of the quaternary ammonium polyacrylamide, and after reaction at a constant temperature of 35°C for 14h, dialysis, and freeze-drying, modified polyacrylamide is obtained;

[0127] S4: Bisphenol A type epoxy resin is sequentially modified by compounding with perfluoroalkyl silane and SBS block copolymer to obtain double-modified epoxy resin;

[0128] Specifically, a bisphenol A type epoxy resin xylene solution with a mass fraction of 35wt.% is prepared, 5.6% of the mass of the bisphenol A type epoxy resin is added as 1H,1H,2H,2H-perfluorooctyltriethoxysilane, and after refluxing at a constant temperature of 80°C for 4h, vacuum distillation is performed to obtain fluorinated epoxy resin; after the fluorinated epoxy resin is melted, 6% of the mass of the fluorinated epoxy resin is added as SBS block copolymer, mechanical stirring is performed at a rotation speed of 500rpm under nitrogen protection for 2h, and after cooling, the product is pulverized to obtain double-modified epoxy resin;

[0129] S5: dispersing the modified hydroxypropyl starch ether and the modified polyacrylamide in anhydrous ethanol to obtain a mixture E, adding the modified nanometer titanium dioxide, the double modified epoxy resin and the curing agent and mixing uniformly to obtain the liquid soil solidifying agent.

[0130] Specifically, the modified hydroxypropyl starch ether and the modified polyacrylamide are added into anhydrous ethanol to obtain a mixture E with a solid content of 20 wt.%, the modified nanometer titanium dioxide is added and ultrasonic dispersion is performed to obtain a mixture F; the double modified epoxy resin is preheated at 45℃, OP-10 in an amount of 4% of the mass of the epoxy resin and polyamide curing agent 650 in an amount of 10% of the mass of the epoxy resin are added, stirring is performed to obtain a mixture G which is added to the mixture F to obtain a pretreated soil solidifying agent, high-speed shearing at a rotation speed of 4000 rpm for 15 min and vacuum degassing for 30 min are performed to obtain the liquid soil solidifying agent.

[0131] Example 2

[0132] The present embodiment provides a liquid soil solidifying agent and a preparation method thereof, wherein the liquid soil solidifying agent comprises the following components in mass parts:

[0133]

[0134] The preparation method specifically comprises the following steps:

[0135] S1: modifying the hydroxypropyl starch ether with maleic anhydride and 2-acrylic acid in sequence to obtain a modified hydroxypropyl starch ether;

[0136] Specifically, the hydroxypropyl starch ether is dispersed in a methanol aqueous solution with a volume ratio of methanol to water of 8:2 to obtain a hydroxypropyl starch ether dispersion liquid with a mass fraction of 12 wt.%, maleic anhydride in an amount of 3% of the mass of the hydroxypropyl starch ether is added under stirring and the pH is adjusted to 5.5 with a sodium hydroxide solution with a concentration of 2.4M to obtain a reaction liquid A, the reaction liquid A is poured into anhydrous ethanol, stirring and precipitation, suction filtration and vacuum drying at 78℃ are performed to obtain a maleic anhydride modified hydroxypropyl starch ether; a maleic anhydride modified hydroxypropyl starch ether solution with a mass fraction of 28 wt.% is prepared, ammonium persulfate in an amount of 0.5% of the mass of the maleic anhydride modified hydroxypropyl starch ether is added, 2-acrylic acid in an amount of 8% of the mass of the maleic anhydride modified hydroxypropyl starch ether is added dropwise under stirring to obtain a reaction liquid B, vacuum distillation and freeze-drying are performed after constant temperature reaction at 55℃ for 3h to obtain the modified hydroxypropyl starch ether;

[0137] S2: modifying the nanometer titanium dioxide with a phosphate and compounding the modified nanometer titanium dioxide with graphene oxide to obtain a modified nanometer titanium dioxide;

[0138] Specifically, a nano-titanium dioxide dispersion with a mass fraction of 5 wt.% was prepared, trisodium phosphate dodecahydrate was added in an amount of 6% of the mass of the nano-titanium dioxide, the mixture was reacted at a constant temperature of 47°C for 6 hours, centrifuged, washed, and vacuum dried to obtain phosphate-modified titanium dioxide; a graphene oxide dispersion with a mass fraction of 0.7 wt.% was prepared, phosphate-modified titanium dioxide was added, wherein the amount of graphene oxide was 3% of the mass of the phosphate-modified titanium dioxide, the mixture was stirred at 67°C for 12 hours, centrifuged, and vacuum dried to obtain modified nano-titanium dioxide;

[0139] S3: polyacrylamide is modified by quaternization and then grafted with chitosan to obtain modified polyacrylamide;

[0140] Specifically, a cationic polyacrylamide dispersion with a mass fraction of 12 wt.% was prepared, 3-chloro-2-hydroxypropyltrimethylammonium chloride was added in an amount of 17% of the mass of the cationic polyacrylamide, and the mixture was stirred at a constant temperature of 58°C for 11 hours under nitrogen protection, dialyzed, and freeze-dried to obtain quaternized polyacrylamide; chitosan was dissolved in a 1% acetic acid solution, the mass fraction of chitosan in the acetic acid solution was 1.5 wt.%, and 1-ethyl-(3-dimethylaminopropyl)carbodiimide hydrochloride was added. and N-hydroxysuccinimide and activated for 2.6 hours to obtain reaction solution C, wherein the mass ratio of 1-ethyl-(3-dimethylaminopropyl)carbodiimide hydrochloride to chitosan is 1.4:1, and the mass ratio of N-hydroxysuccinimide to chitosan is 1:1, preparing a quaternized polyacrylamide solution and mixing it with reaction solution C to obtain reaction solution D, wherein the amount of chitosan added is 5% of the mass of the quaternized polyacrylamide, isothermally reacted at 40° C. for 16 hours, dialyzed, and freeze-dried to obtain modified polyacrylamide;

[0141] S4: Compound-modifying bisphenol A epoxy resin with perfluoroalkylsilane and SBS block copolymer in sequence to obtain a double-modified epoxy resin;

[0142] Specifically, a xylene solution of bisphenol A epoxy resin with a mass fraction of 32 wt.% was prepared, 1H,1H,2H,2H-perfluorooctyltriethoxysilane was added in an amount of 5% by mass of the bisphenol A epoxy resin, and the mixture was refluxed at a constant temperature of 70°C for 3 hours, followed by reduced pressure distillation to obtain a fluorinated epoxy resin; the fluorinated epoxy resin was melted, and an SBS block copolymer was added in an amount of 8% by mass of the fluorinated epoxy resin, and the mixture was mechanically stirred at a speed of 600 rpm under nitrogen protection for 3 hours, cooled, and then crushed to obtain a double-modified epoxy resin;

[0143] S5: dispersing modified hydroxypropyl starch ether and modified polyacrylamide in anhydrous ethanol to obtain a mixture E, adding modified nano titanium dioxide, double-modified epoxy resin and curing agent and mixing evenly to obtain the liquid soil curing agent.

[0144] Specifically, modified hydroxypropyl starch ether and modified polyacrylamide are added into anhydrous ethanol to obtain a mixture E with a solid content of 27 wt.%, modified nano-titanium dioxide is added and ultrasonic dispersion is performed to obtain a mixture F; a double-modified epoxy resin is preheated at 46℃, OP-10 with a dosage of 3% of the mass of the epoxy resin and T31 curing agent with a dosage of 12.5% of the mass of the epoxy resin are added, stirring is performed to obtain a mixture G, which is added to the mixture F to obtain a pretreated soil curing agent, high-speed shearing at a speed of 5000 rpm for 18 min and vacuum degassing for 20 min are performed to obtain the liquid soil curing agent.

[0145] Example 3

[0146] The present embodiment provides a liquid soil curing agent and a preparation method thereof, wherein the liquid soil curing agent comprises the following components in mass parts:

[0147]

[0148] The preparation method specifically comprises the following steps:

[0149] S1: hydroxypropyl starch ether is modified with maleic anhydride and 2-acrylic acid in sequence to obtain modified hydroxypropyl starch ether;

[0150] Specifically, hydroxypropyl starch ether is dispersed in a methanol aqueous solution with a volume ratio of methanol to water of 9:1 to obtain a hydroxypropyl starch ether dispersion liquid with a mass fraction of 15 wt.%, maleic anhydride with a dosage of 7% of the mass of the hydroxypropyl starch ether is added under stirring and the pH is adjusted to 6 with a 2.7M sodium hydroxide solution to obtain a reaction liquid A, the reaction liquid A is poured into anhydrous ethanol, stirring and precipitation are performed, suction filtration is performed, and vacuum drying is performed at 80℃ to obtain maleic anhydride modified hydroxypropyl starch ether; a maleic anhydride modified hydroxypropyl starch ether solution with a mass fraction of 20 wt.% is prepared, ammonium persulfate with a dosage of 1% of the mass of the maleic anhydride modified hydroxypropyl starch ether is added, and 2-acrylic acid with a dosage of 10% of the mass of the maleic anhydride modified hydroxypropyl starch ether is added dropwise under stirring to obtain a reaction liquid B, vacuum distillation and freeze-drying are performed after constant temperature reaction at 45℃ for 4.4h to obtain modified hydroxypropyl starch ether;

[0151] S2: nano-titanium dioxide is modified by phosphate and is compounded with graphene oxide to obtain modified nano-titanium dioxide;

[0152] Specifically, a nano-titanium dioxide dispersion solution with a mass fraction of 10 wt.% is prepared, 9% of the mass of the nano-titanium dioxide is added as trisodium phosphate dodecahydrate, and after reaction at a constant temperature of 40℃ for 7h, centrifugal separation, washing, and vacuum drying are performed to obtain phosphate-modified titanium dioxide; a graphene oxide dispersion solution with a mass fraction of 0.8 wt.% is prepared, and the phosphate-modified titanium dioxide is added, wherein the mass of graphene oxide is 1% of the mass of the phosphate-modified titanium dioxide, and after stirring at 60℃ for 14h, centrifugal separation, and vacuum drying, modified nano-titanium dioxide is obtained;

[0153] S3: After the polyacrylamide is modified by quaternary ammonium, graft copolymerization is performed with chitosan to obtain modified polyacrylamide;

[0154] Specifically, a cationic polyacrylamide dispersion solution with a mass fraction of 14 wt.% is prepared, 18% of the mass of the cationic polyacrylamide is added as 3-chloro-2-hydroxypropyl trimethylammonium chloride, stirring is performed under nitrogen protection at a constant temperature of 60℃ for 12h, dialysis is performed, and freeze-drying is performed to obtain quaternary ammonium polyacrylamide; chitosan is dissolved in a 1% acetic acid solution, the mass fraction of chitosan in the acetic acid solution is 1.3 wt.%, and 1-ethyl-(3-dimethylaminopropyl) carbodiimide hydrochloride and N-hydroxysuccinimide are added and activated for 2.9h to obtain reaction solution C, wherein the mass ratio of 1-ethyl-(3-dimethylaminopropyl) carbodiimide hydrochloride to chitosan is 1.2:1, and the mass ratio of N-hydroxysuccinimide to chitosan is 1.2:1; a quaternary ammonium polyacrylamide solution is prepared and mixed with reaction solution C to obtain reaction solution D, wherein the mass of chitosan is 4% of the mass of the quaternary ammonium polyacrylamide, and after reaction at a constant temperature of 45℃ for 12h, dialysis, and freeze-drying, modified polyacrylamide is obtained;

[0155] S4: Bisphenol A type epoxy resin is sequentially modified by complex modification with perfluoroalkyl silane and SBS block copolymer to obtain a double-modified epoxy resin;

[0156] Specifically, a bisphenol A type epoxy resin xylene solution with a mass fraction of 30 wt.% is prepared, 6% of the mass of the bisphenol A type epoxy resin is added as 1H,1H,2H,2H-perfluorooctyl triethoxysilane, vacuum distillation is performed after refluxing at a constant temperature of 75℃ for 3.4h to obtain fluorinated epoxy resin; after the fluorinated epoxy resin is melted, 5% of the mass of the fluorinated epoxy resin is added as SBS block copolymer, mechanical stirring is performed under nitrogen protection at a rotation speed of 550 rpm for 2.5h, and after cooling, the product is pulverized to obtain a double-modified epoxy resin;

[0157] S5: Modified hydroxypropyl starch ether and modified polyacrylamide are dispersed in anhydrous ethanol to obtain mixture E, and modified nano-titanium dioxide, double-modified epoxy resin, and curing agent are uniformly mixed to obtain the liquid soil curing agent.

[0158] Specifically, the modified hydroxypropyl starch ether and the modified polyacrylamide are added into anhydrous ethanol to obtain a mixture E with a solid content of 30 wt.%, the modified nanometer titanium dioxide is added and ultrasonic dispersed to obtain a mixture F; the double modified epoxy resin is preheated at 48℃, then OP-10 with a feeding amount of 5% of the mass of the epoxy resin and polyamide curing agent 650 with a feeding amount of 15% of the mass of the epoxy resin are added, the mixture G is stirred to obtain a pretreated soil curing agent, which is high-speed sheared at a rotating speed of 3000 rpm for 10 min and vacuum degassed for 25 min to obtain the liquid soil curing agent.

[0159] Example 4

[0160] The present embodiment provides a liquid soil curing agent and a preparation method thereof, wherein the liquid soil curing agent comprises the following components by mass:

[0161]

[0162] The preparation method specifically comprises the following steps:

[0163] S1: the hydroxypropyl starch ether is modified with maleic anhydride and 2-acrylic acid in sequence to obtain a modified hydroxypropyl starch ether;

[0164] Specifically, the hydroxypropyl starch ether is dispersed in a methanol aqueous solution with a volume ratio of methanol to water of 7:3 to obtain a hydroxypropyl starch ether dispersion liquid with a mass fraction of 14 wt.%, maleic anhydride with a feeding amount of 8% of the mass of the hydroxypropyl starch ether is added under stirring and the pH is adjusted to 6.8 with a 3M sodium hydroxide solution to obtain a reaction liquid A, the reaction liquid A is poured into anhydrous ethanol and stirred to precipitate, then suction filtered and vacuum dried at 70℃ to obtain a maleic anhydride modified hydroxypropyl starch ether; a maleic anhydride modified hydroxypropyl starch ether solution with a mass fraction of 30 wt.% is prepared, ammonium persulfate with a feeding amount of 0.88% of the mass of the maleic anhydride modified hydroxypropyl starch ether is added, and 2-acrylic acid with a feeding amount of 7% of the mass of the maleic anhydride modified hydroxypropyl starch ether is added dropwise under stirring to obtain a reaction liquid B, which is reacted at a constant temperature of 52℃ for 5h, then distilled under reduced pressure and freeze-dried to obtain the modified hydroxypropyl starch ether;

[0165] S2: the nanometer titanium dioxide is modified by phosphate and compounded with graphene oxide to obtain a modified nanometer titanium dioxide;

[0166] Specifically, a nano-titania dispersion solution with a mass fraction of 7wt.% is prepared, 10% of the mass of the nano-titania by mass of trisodium phosphate dodecahydrate is added, and after reaction at a constant temperature of 50℃ for 7.8h, centrifugal separation, washing, and vacuum drying are performed to obtain phosphate-modified titania; a graphene oxide dispersion solution with a mass fraction of 1wt.% is prepared, the phosphate-modified titania is added, the mass of the graphene oxide is 2% of the mass of the phosphate-modified titania, stirring is performed at 70℃ for 13.5h, centrifugal separation, and vacuum drying are performed to obtain modified nano-titania;

[0167] S3: After the polyacrylamide is modified by quaternary ammonium, graft copolymerization is performed with chitosan to obtain modified polyacrylamide;

[0168] Specifically, a cationic polyacrylamide dispersion solution with a mass fraction of 15wt.% is prepared, 20% of the mass of the cationic polyacrylamide by mass of 3-chloro-2-hydroxypropyl trimethylammonium chloride is added, stirring is performed at a constant temperature of 50℃ for 11.5h under nitrogen protection, dialysis, and freeze-drying are performed to obtain quaternary ammonium polyacrylamide; chitosan is dissolved in a 1% acetic acid solution, the mass fraction of the chitosan in the acetic acid solution is 1wt.%, 1-ethyl-(3-dimethylaminopropyl) carbodiimide hydrochloride and N-hydroxysuccinimide are added and activated for 3h to obtain reaction solution C, the mass ratio of 1-ethyl-(3-dimethylaminopropyl) carbodiimide hydrochloride to chitosan is 1.5:1, and the mass ratio of N-hydroxysuccinimide to chitosan is 1.3:1, a quaternary ammonium polyacrylamide solution is prepared and mixed with reaction solution C to obtain reaction solution D, the mass of the chitosan is 3% of the mass of the quaternary ammonium polyacrylamide, and reaction is performed at a constant temperature of 42℃ for 15h, dialysis, and freeze-drying are performed to obtain modified polyacrylamide;

[0169] S4: Bisphenol A type epoxy resin is sequentially modified by complexing with perfluoroalkyl silane and SBS block copolymer to obtain a double-modified epoxy resin;

[0170] Specifically, a bisphenol A type epoxy resin xylene solution with a mass fraction of 25wt.% is prepared, 5.3% of the mass of the bisphenol A type epoxy resin by mass of 1H,1H,2H,2H-perfluorooctyl triethoxysilane is added, vacuum distillation is performed after refluxing at a constant temperature of 76℃ for 3.7h to obtain fluorinated epoxy resin; the fluorinated epoxy resin is melted, 7% of the mass of the fluorinated epoxy resin by mass of SBS block copolymer is added, mechanical stirring is performed at a rotation speed of 570rpm under nitrogen protection for 2.8h, and after cooling, the product is pulverized to obtain a double-modified epoxy resin;

[0171] S5: Modified hydroxypropyl starch ether and modified polyacrylamide are dispersed in anhydrous ethanol to obtain mixture E, modified nano-titania, double-modified epoxy resin, and curing agent are added and uniformly mixed to obtain the liquid soil curing agent.

[0172] Specifically, modified hydroxypropyl starch ether and modified polyacrylamide were added into anhydrous ethanol to obtain a mixture E with a solid content of 25 wt.%, modified nano-titanium dioxide was added and ultrasonic dispersion was performed to obtain mixture F; after preheating, 4.2% of OP-10 by mass of the epoxy resin and 14% of T31 curing agent by mass of the epoxy resin were added to mixture F, stirring was performed to obtain mixture G, and mixture G was added to mixture F to obtain a pretreated soil curing agent, which was subjected to high-speed shearing at a rotation speed of 4600 rpm for 20 min and vacuum degassing for 28 min to obtain the liquid soil curing agent.

[0173] Comparative Example 1

[0174] The present comparative example provides a liquid soil curing agent, which is different from Example 1 in that in step S1, the feeding amount of maleic anhydride is 15% by mass of the hydroxypropyl starch ether, and other operation steps and process parameters are completely the same as those of Example 1.

[0175] Comparative Example 2

[0176] The present comparative example provides a liquid soil curing agent, which is different from Example 1 in that in step S1, the feeding amount of maleic anhydride is 1% by mass of the hydroxypropyl starch ether, and other operation steps and process parameters are completely the same as those of Example 1.

[0177] Comparative Example 3

[0178] The present comparative example provides a liquid soil curing agent, which is different from Example 1 in that in step S4, the feeding amount of 1H, 1H, 2H, 2H-perfluorooctyl triethoxysilane is 10% by mass of the bisphenol A type epoxy resin, and other operation steps and process parameters are completely the same as those of Example 1.

[0179] Comparative Example 4

[0180] The present comparative example provides a liquid soil curing agent, which is different from Example 1 in that in step S4, the feeding amount of 1H, 1H, 2H, 2H-perfluorooctyl triethoxysilane is 1% by mass of the bisphenol A type epoxy resin, and other operation steps and process parameters are completely the same as those of Example 1.

[0181] The liquid soil curing agents of Examples 1-4 and Comparative Examples 1-4 were subjected to performance tests, and the specific process was as follows:

[0182] According to CJ / T 486-2015 “Soil Curing Additive”, the 7d acid immersion and non-acid immersion unconfined compressive strengths and the 28d acid immersion and non-acid immersion unconfined compressive strengths of the liquid soil curing agents obtained in Examples 1-4 and Comparative Examples 1-4 were detected;

[0183] The test results are shown in Table 1.

[0184] Table 1: Liquid soil stabilizer performance test results of Examples 1-4 and Comparative Examples 1-4

[0185]

[0186] As shown in Table 1, the liquid soil stabilizer prepared by Examples 1-4 has good unconfined compressive strength and acid and alkali resistance.

[0187] As shown by the test results of Example 1 and Comparative Examples 1 and 2, the acyl group in maleic anhydride reacts with the hydroxyl group in the hydroxypropyl starch ether molecule to form a cross-linked structure. Too much maleic anhydride can cause excessive cross-linking, making the material too brittle, reducing its ductility and flexibility; too little maleic anhydride cannot fully cross-link, resulting in an incomplete network structure of the modified product and insufficient performance.

[0188] As shown by the test results of Example 1 and Comparative Examples 3 and 4, a suitable amount of 1H, 1H, 2H, 2H-perfluorooctyltriethoxysilane can improve the corrosion resistance and environmental adaptability of the epoxy resin, which is very important for the long-term stability and durability of the soil stabilizer. Too much material will cause excessive modification of the epoxy resin, making the fluorination degree of the resin too high, resulting in a decrease in the mechanical properties of the resin and an increase in brittleness; too little material will result in insufficient fluorination of the epoxy resin, resulting in incomplete fluorination modification, so that the acid and alkali resistance, chemical corrosion resistance and other properties of the epoxy resin cannot be significantly improved, thereby affecting the stability of the final stabilizer in complex environments.

[0189] The above is merely a specific implementation of the present application, but the protection scope of the present application is not limited thereto. It should be understood by those skilled in the art that any changes or replacements within the technical scope disclosed by the present application can be easily conceived by those skilled in the art, and all such changes or replacements fall within the protection scope and disclosure scope of the present application.

Claims

1. A method for preparing a liquid soil solidifier, characterized in that: The preparation method comprises: S1: Modifying hydroxypropyl starch ether with maleic anhydride and 2-acrylic acid in sequence to obtain modified hydroxypropyl starch ether; specifically, dispersing hydroxypropyl starch ether in a methanol-water solution to obtain a hydroxypropyl starch ether dispersion, adding maleic anhydride while stirring, and adjusting the pH with sodium hydroxide solution to obtain a reaction solution A, pouring the reaction solution A into anhydrous ethanol, stirring and precipitating, filtering, and vacuum drying to obtain maleic anhydride-modified hydroxypropyl starch ether; preparing a maleic anhydride-modified hydroxypropyl starch ether solution, adding ammonium persulfate, and adding 2-acrylic acid dropwise while stirring to obtain a reaction solution B, reacting at a constant temperature, and then distilling under reduced pressure and freeze-drying to obtain the modified hydroxypropyl starch ether; the amount of maleic anhydride added is 3-8% of the mass of the hydroxypropyl starch ether; S2: Compounding nano-titanium dioxide with graphene oxide after phosphate modification to obtain modified nano-titanium dioxide; specifically, preparing a nano-titanium dioxide dispersion, adding trisodium phosphate dodecahydrate, reacting at a constant temperature, centrifuging, washing, and vacuum drying to obtain phosphate-modified titanium dioxide; preparing a graphene oxide dispersion, adding phosphate-modified titanium dioxide, stirring, centrifuging, and vacuum drying to obtain modified nano-titanium dioxide; S3: quaternizing polyacrylamide and grafting it with chitosan to obtain modified polyacrylamide; specifically, preparing a cationic polyacrylamide dispersion, adding 3-chloro-2-hydroxypropyltrimethylammonium chloride, stirring at a constant temperature under nitrogen protection, dialyzing, and freeze-drying to obtain quaternized polyacrylamide; dissolving chitosan in a 1% acetic acid solution, adding 1-ethyl-(3-dimethylaminopropyl)carbodiimide hydrochloride and N-hydroxysuccinimide and activating the mixture to obtain a reaction solution C, preparing a quaternized polyacrylamide solution and mixing it with the reaction solution C to obtain a reaction solution D, reacting at a constant temperature, dialyzing, and freeze-drying to obtain the modified polyacrylamide; S4: Compound-modifying bisphenol A epoxy resin with perfluoroalkylsilane and SBS block copolymer in sequence to obtain a double-modified epoxy resin; specifically, preparing a xylene solution of bisphenol A epoxy resin, adding 1H,1H,2H,2H-perfluorooctyltriethoxysilane, wherein the amount of 1H,1H,2H,2H-perfluorooctyltriethoxysilane is 5-6% of the mass of the bisphenol A epoxy resin; performing reduced pressure distillation after constant temperature reflux to obtain a fluorinated epoxy resin; melting the fluorinated epoxy resin, adding the SBS block copolymer, mechanically stirring under nitrogen protection, cooling, and then crushing to obtain a double-modified epoxy resin; S5: dispersing modified hydroxypropyl starch ether and modified polyacrylamide in anhydrous ethanol to obtain a mixture E, adding modified nano titanium dioxide, double-modified epoxy resin and a curing agent and mixing evenly to obtain the liquid soil curing agent; specifically comprising: adding modified hydroxypropyl starch ether and modified polyacrylamide to anhydrous ethanol to obtain a mixture E, adding modified nano titanium dioxide, and ultrasonically dispersing to obtain a mixture F; preheating the double-modified epoxy resin, adding OP-10 and a curing agent, stirring to obtain a mixture G, and adding the mixture to the mixture F to obtain a pretreated soil curing agent, high-speed shearing, and vacuum degassing to obtain the liquid soil curing agent.

2. The method for preparing a liquid soil solidifier according to claim 1, wherein: In S1: The volume ratio of methanol to water in the methanol-water solution is 7:3-9:1; The mass fraction of the hydroxypropyl starch ether dispersion is 10-15wt.%; The concentration of the sodium hydroxide solution is 2-3M; The pH value is adjusted to 5-6 using sodium hydroxide solution; The vacuum drying temperature is 70-80°C.

3. The method for preparing a liquid soil solidifier according to claim 1, wherein: In S1: The mass fraction of the maleic anhydride modified hydroxypropyl starch ether solution is 20-30wt.%; The amount of ammonium persulfate added is 0.5-1% of the mass of maleic anhydride modified hydroxypropyl starch ether; The feeding amount of the 2-acrylic acid is 5-10% of the mass of the maleic anhydride modified hydroxypropyl starch ether; The temperature of the constant temperature reaction of the reaction solution B is 45-55°C; The constant temperature reaction time of the reaction solution B is 3-5 hours.

4. The method for preparing a liquid soil solidifier according to claim 1, wherein: In S2: The mass fraction of the nano-titanium dioxide dispersion is 5-10wt.%; The feeding amount of the trisodium phosphate dodecahydrate is 5-10% of the mass of the nano-titanium dioxide; The temperature of the isothermal reaction is 40-50°C; The isothermal reaction time is 6-8 hours.

5. The method for preparing a liquid soil solidifier according to claim 1, characterized in that: In S2: The mass fraction of the graphene oxide dispersion is 0.5-1wt.%; The feeding amount of the graphene oxide is 1-3% of the mass of the phosphate-modified titanium dioxide.

6. The method for preparing a liquid soil solidifier according to claim 1, characterized in that: In S3: The feeding amount of the 3-chloro-2-hydroxypropyltrimethylammonium chloride is 15-20% of the mass of the cationic polyacrylamide; The temperature of the constant temperature stirring under nitrogen protection is 50-60°C; The time of constant temperature stirring under nitrogen protection is 10-12h; The mass fraction of the chitosan in the acetic acid solution is 1-1.5 wt.%; The mass ratio of 1-ethyl-(3-dimethylaminopropyl)carbodiimide hydrochloride to chitosan is 1-1.5:1; The mass ratio of N-hydroxysuccinimide to chitosan is 1-1.5:1; The activation time is 2-3h; The mass fraction of the quaternized polyacrylamide dispersion is 15-20wt.%; The feeding amount of the chitosan is 3-6% of the mass of the quaternized polyacrylamide.

7. The method for preparing a liquid soil solidifier according to claim 1, characterized in that: In S4: The mass fraction of the bisphenol A epoxy resin acetone solution is 25-35wt.%; The temperature of the constant temperature reflux reaction is 70-80°C; The constant temperature reflux reaction time is 3-4h; The feeding amount of the SBS block copolymer is 5-8% of the mass of the fluorinated epoxy resin.

8. The method for preparing a liquid soil solidifier according to claim 1, characterized in that: In S5: The solid content of the mixture E is 20-30 wt.%; The curing agent is polyamide curing agent 650 or T31 curing agent; The double-modified epoxy resin is preheated to a temperature of 45-50° C. The feeding amount of OP-10 is 3-5% of the mass of epoxy resin; The rotation speed of the pre-treated soil solidifying agent high-speed shear is 3000-5000rpm; The high-speed shearing time of the pre-treated soil solidifying agent is 10-20 minutes; The vacuum degassing time is 20-30 minutes.

9. A liquid soil solidifying agent prepared by the preparation method according to any one of claims 1 to 8, characterized in that: The liquid soil solidifier comprises the following components in parts by mass:

10. Use of a liquid soil solidifying agent prepared by the preparation method according to any one of claims 1 to 8 in a building foundation.

Images