Liquid soil stabilizer as well as preparation method and application thereof

Abstract

The invention provides a liquid soil stabilizer as well as a preparation method and application thereof, and belongs to the field of soil stabilizers. Hydroxypropyl starch ether is introduced, and maleic anhydride and 2-acrylic acid are used for modification, so that crosslinking sites and a side chain network structure are increased, and the water resistance is improved; secondly, the dispersity of the nano titanium dioxide is improved through phosphate modification, the nano titanium dioxide grows on the surface of the graphene oxide in situ, and the interface bonding force is enhanced; ionic bond binding sites are increased through quaternization of polyacrylamide, and the biocompatibility and durability of the hydrogel are improved through chitosan grafting; in addition, a C-F bond is introduced into the fluorinated modified bisphenol A epoxy resin, the acid and alkali resistance is improved, the fluorinated modified bisphenol A epoxy resin is blended with SBS to form a microphase separation structure, and the toughness is enhanced. Through the synergistic effect of multiple components, the mechanical property, durability, corrosion resistance and environmental adaptability of a curing system are remarkably improved, and the long-term stability and reliability of the material under complex conditions are ensured.

Description

Technical Field

[0001] The invention belongs to the technical field of soil solidifiers and relates to a liquid soil solidifier and a preparation method and application thereof. Background Art

[0002] Traditional soil stabilizers are usually based on inorganic materials such as cement, lime, and soil binders. Their solidification effect mainly relies on chemical reactions and physical adsorption. For example, cement and lime combine with particles in the soil 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 specific soil types, and dependence on construction conditions. Therefore, with the advancement of technology and the enhancement of environmental awareness, researchers have begun to explore more advanced and environmentally friendly liquid soil stabilizers to overcome the shortcomings of these traditional methods.

[0003] As an innovative soil improvement material, liquid soil stabilizers 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 is that they can cross-link with soil particles through chemical reactions to improve the compressive strength and stability of the soil; at the same time, they usually have good permeability and fluidity, allowing the stabilizer to be evenly distributed in the soil, thereby achieving a more effective curing effect. In recent years, with the increasing demand for environmentally friendly materials, liquid soil stabilizers based on natural polymer materials have gradually become a research focus. These materials can not only effectively improve soil properties, but also reduce negative impacts on the environment.

[0004] However, existing liquid soil stabilizers still have shortcomings in terms of durability and adaptability to different soil types: some stabilizers cannot maintain their strength stably after curing and will decay over time, making it difficult to meet engineering requirements. In addition, many liquid soil stabilizers are highly selective in terms of soil when applied and cannot be widely adapted to different soil conditions, which limits their scope of application. Summary of the invention

[0005] In view of the above problems, the purpose of the present invention is to provide a liquid soil curing agent and its preparation method and application. Hydroxypropyl starch ether is introduced in the present invention and modified by maleic anhydride and 2-acrylic acid. Maleic anhydride grafting modification introduces carboxyl groups and increases cross-linking sites. 2-acrylic acid modification forms a side chain network structure through free radical polymerization, thereby improving its water resistance. By phosphate modification of the surface of nano-titanium dioxide, the dispersibility of titanium dioxide is improved and phosphate groups are introduced. In situ growth on graphene oxide enhances dispersibility and interfacial bonding through π-π stacking. Quaternization of polyacrylamide can increase ionic bond binding sites, and grafting of chitosan improves its biocompatibility and durability. Fluorination modification of bisphenol A epoxy resin can introduce CF bonds to improve acid and alkali resistance, and blending with SBS block copolymers forms a microphase separation structure to improve the toughness of the material. Through the synergistic enhancement 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 object, the present invention adopts the following technical solutions:

[0007] In a first aspect, the present invention provides a method for preparing a liquid soil solidifier, the method for preparing the liquid soil solidifier comprising:

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

[0009] S2: modifying nano-titanium dioxide with phosphate and then compounding it with graphene oxide to obtain modified nano-titanium dioxide;

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

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

[0012] 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.

[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 the pH with a 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 dropping 2-acrylic acid under stirring to obtain a reaction solution B, reacting at a constant temperature, performing reduced pressure distillation, and freeze-drying to obtain a modified hydroxypropyl starch ether;

[0014] S2: 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;

[0015] S3: 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 a 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 solution C, preparing a quaternary ammonium 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 a modified polyacrylamide;

[0016] S4: preparing a xylene solution of bisphenol A epoxy resin, adding 1H,1H,2H,2H-perfluorooctyltriethoxysilane, refluxing at a constant temperature and then distilling under reduced pressure to obtain a fluorinated epoxy resin; melting the fluorinated epoxy resin and adding the SBS block copolymer, mechanically stirring under nitrogen protection, cooling and then crushing to obtain a double-modified epoxy resin;

[0017] S5: 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.

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

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

[0020] In some optional embodiments, the feeding amount of maleic anhydride is 3-8% of the mass of 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 unlisted values ​​within the numerical range are also applicable.

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

[0022] In some optional embodiments, the pH is adjusted to 5-6 using sodium hydroxide solution, for example, 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 unlisted values ​​within the numerical range are also applicable.

[0023] In some optional embodiments, the vacuum drying temperature 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 unlisted values ​​within the numerical range are also applicable.

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

[0025] In some optional embodiments, the dosage 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 unlisted values ​​within the numerical range are also applicable.

[0026] In some optional embodiments, the feeding amount of 2-acrylic 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 unlisted values ​​within the numerical range are also applicable.

[0027] In some optional embodiments, the temperature of the constant temperature reaction of the reaction liquid 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 unlisted values ​​within the numerical range are also applicable.

[0028] In some optional embodiments, the constant temperature reaction time of the reaction liquid 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 unlisted values ​​within the numerical range are also applicable.

[0029] As a preferred technical solution of the present invention, in step S2, the mass fraction of the nano-titanium dioxide dispersion 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 unlisted values ​​within the numerical range are also applicable.

[0030] In some optional embodiments, the feeding amount of the 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 unlisted values ​​within the numerical range are also applicable.

[0031] In some optional embodiments, the temperature of the isothermal 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 unlisted values ​​within the numerical range are also applicable.

[0032] In some optional embodiments, the isothermal 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 is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0033] In some optional embodiments, the mass fraction of the graphene oxide dispersion 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 is not limited to the listed values, and other unlisted values ​​within the numerical 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 is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

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

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

[0038] In some optional embodiments, the feeding amount of the 3-chloro-2-hydroxypropyltrimethylammonium chloride is 15-20% of the 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 unlisted values ​​within the numerical range are also applicable.

[0039] In some optional embodiments, the temperature of 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 unlisted values ​​within the numerical range are also applicable.

[0040] In some optional embodiments, the time for 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 unlisted values ​​within the numerical range are also applicable.

[0041] In some optional embodiments, the mass fraction of 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 unlisted values ​​within the numerical range are also applicable.

[0042] In some optional embodiments, the mass ratio of 1-ethyl-(3-dimethylaminopropyl)carbodiimide hydrochloride to 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 unlisted values ​​within the numerical range are also applicable.

[0043] In some optional embodiments, the mass ratio of N-hydroxysuccinimide to 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 unlisted values ​​within the numerical 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 is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0045] In some optional embodiments, the mass fraction of the quaternized 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 is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0046] In some optional embodiments, the amount of chitosan added is 3-6% of the mass of quaternized polyacrylamide, for example, 3%, 3.3%, 3.6%, 3.9%, 4.2%, 4.5%, 4.8%, 5%, 5.3%, 5.6% or 6%, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0047] In some optional embodiments, the temperature of the constant temperature reaction of the reaction liquid D is 35-45°C, for example, it can be 35°C, 36°C, 37°C, 38°C, 39°C, 40°C, 41°C, 42°C, 43°C, 44°C or 45°C, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

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

[0049] As a preferred technical solution of the present invention, in step S4, the mass fraction of the bisphenol A 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 is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0050] In some optional embodiments, the feeding amount of the 1H,1H,2H,2H-perfluorooctyltriethoxysilane is 5-6% of the mass of the bisphenol A epoxy resin, for example, it can be 5%, 5.1%, 5.2%, 5.3%, 5.4%, 5.5%, 5.6%, 5.7%, 5.8%, 5.9% or 6%, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0051] In some optional embodiments, the temperature of the constant temperature reflux reaction 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 unlisted values ​​within the numerical range are also applicable.

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

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

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

[0055] In some optional embodiments, the time of mechanical stirring under nitrogen protection 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 is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

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

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

[0058] In some optional embodiments, the feeding amount of OP-10 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 is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0059] The dosage of the curing agent 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 is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0060] In some optional embodiments, the rotation speed of the high-speed shear of the pretreated soil solidifier is 3000-5000rpm, for example, it can be 3000rpm, 3200rpm, 3400rpm, 3600rpm, 3800rpm, 4000rpm, 4200rpm, 4400rpm, 4600rpm, 4800rpm or 5000rpm, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0061] In some optional embodiments, the high-speed shear time of the pretreated soil solidifier 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 is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0062] In some optional embodiments, the vacuum degassing time 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 is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0063] In a second aspect, the present invention provides a liquid soil solidifier, wherein the liquid soil solidifier comprises the following components in parts by weight:

[0064]

[0065] In some optional embodiments, the mass parts of the modified hydroxypropyl starch ether are 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 it is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

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

[0067] In some optional embodiments, the mass parts of the modified polyacrylamide are 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 it is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0068] In some optional embodiments, the mass parts of the double-modified epoxy resin are 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 it is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0069] Hydroxypropyl starch ether is introduced in the present invention. Hydroxypropyl starch ether is a polysaccharide derivative obtained by hydroxypropylating natural starch. Its molecular structure contains a large number of hydroxyl groups and ether groups. These polar groups give hydroxypropyl starch ether excellent hydrophilicity and water solubility. Specifically, the hydroxyl groups in the molecule can interact with water molecules through hydrogen bonds, thereby enhancing its solubility and dispersibility in water. This property enables hydroxypropyl starch ether to be evenly distributed in an aqueous solution to form a stable solution, which is crucial for the subsequent application in the preparation of a soil solidifying agent.

[0070] In addition, the introduction of hydroxypropyl substituent groups destroys some of the intermolecular and intramolecular hydrogen bonds in the natural starch molecular chain. This characteristic leads to a significant improvement in its dispersibility in water, enabling it to form a uniform dispersion system, which is of great significance for improving the effect of the curing agent. Especially in soil curing applications, hydroxypropyl starch ether can form an adhesive polymer network through its good thickening and film-forming properties, thereby enhancing the binding force of soil particles. The stretching effect of the molecular chain in the aqueous solution enables it to form a polymer viscosity network, which plays a preliminary physical cross-linking role, improves the initial coagulation ability of the soil curing agent, and thus provides a basis for subsequent curing and reinforcement.

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

[0072] Through the introduction of maleic anhydride, the newly added double bond structure and carboxyl group on the molecular chain of the modified hydroxypropyl starch ether can significantly improve its chemical stability, especially under different environmental conditions (such as acid and alkali 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 an active site in the subsequent free radical polymerization reaction to undergo chain growth reaction with monomers (such as 2-acrylic acid), thereby forming a three-dimensional cross-linked network structure. The formation of this network further enhances the water resistance and mechanical properties of the curing agent.

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

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

[0075] Nano titanium dioxide is introduced as a filler in the present invention. 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 show excellent reactivity and high adsorption at the nanometer size, which makes nano titanium dioxide an ideal filler. Its surface contains a certain number of hydroxyl groups, which can not only enhance its hydrophilicity, but also provide abundant active sites, which help to form stronger chemical bonds with other organic components. In this way, nano titanium dioxide can effectively combine with the organic polymer network to play a reinforcing role, thereby significantly improving the compressive strength, durability and mechanical properties of the curing agent.

[0076] As an inorganic filler, nano-titanium dioxide can be evenly embedded in the three-dimensional network structure of organic polymers to enhance 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 between the curing agent and soil particles, thereby improving the overall structure and strength of the soil, making it show more excellent performance in the soil curing process. The use of nano-titanium dioxide filler in the curing agent can effectively improve the physical properties of the soil, improve its compression and tensile resistance, and enhance the durability of the curing agent.

[0077] In order to further improve the performance of nano titanium dioxide, the present invention uses phosphate to modify it. By introducing trisodium phosphate, phosphate reacts chemically with the hydroxyl groups on the surface of nano titanium dioxide to form a phosphate layer, and at the same time partially forms a Ti-OP coordination bond structure. This reaction significantly improves the surface energy and chemical stability of nano titanium dioxide; the introduction of the phosphate layer not only enhances the hydrophilicity of its surface, but also improves its compatibility with other components, so that the modified nano titanium dioxide has better durability and chemical stability in a variety of 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 the application of soil stabilizers, phosphate groups can have an affinity with these components, promote the interaction between particles, and enhance their physical cross-linking and chemical bonding. This phosphate modification not only improves the chemical stability of the material, but also makes it exhibit stronger corrosion resistance and long-term stability in acidic and alkaline environments, thereby greatly improving the adaptability and reliability of soil stabilizers in complex environments.

[0079] Furthermore, the surface of phosphate-modified nano-titanium dioxide is in situ grown on graphene oxide. Graphene oxide has a unique two-dimensional flaky structure, which provides a larger specific surface area, allowing it to be more evenly dispersed 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 curing agent. The rich oxygen-containing functional groups on the surface of graphene oxide enable it to form a variety of interactions with phosphoric acid-modified titanium dioxide and other polar or charged components (such as quaternized polyacrylamide), such as hydrogen bonds, electrostatic effects or coordination effects. These interactions not only significantly improve the interfacial bonding force of the material, but also enhance the mechanical properties and chemical stability of the material.

[0080] The π-π stacking effect and surface chemical reaction between graphene oxide and nano-titanium dioxide also help to form a tight interface bond, which provides a guarantee for 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 compressive resistance of composite materials. At the same time, the introduction of graphene oxide also enables the modified curing agent to maintain good structural stability and long-term performance in the face of extreme environments.

[0081] Cationic polyacrylamide is a polymer material formed by copolymerization of acrylamide and cationic monomers, and its molecular chain contains positively charged cationic functional groups. Due to the presence of these cationic functional groups, cationic polyacrylamide can bind to the surface of negatively charged soil particles through electrostatic adsorption, thereby significantly improving its adsorption capacity and binding strength to soil particles. This characteristic makes cationic polyacrylamide have very important application potential in soil solidification and improvement of soil structure.

[0082] The molecular chain of cationic polyacrylamide has strong tensile properties and high chemical stability. It can form a three-dimensional network structure through cross-linking or hydrogen bonding. This feature further enhances its physical bonding with soil particles. Due to the flexibility and hydrophilicity of its molecular chain, cationic polyacrylamide can not only improve the rheological properties of the curing agent, making it more soluble and fluid in aqueous solution, but also promote the uniform dispersion and deep penetration of the curing agent in the soil. This feature is crucial to the construction process of the soil curing agent, helping to ensure that the curing agent can effectively cover the soil surface and form a stronger bond with the soil particles, thereby improving the curing effect.

[0083] By introducing 3-chloro-2-hydroxypropyltrimethylammonium chloride to modify cationic polyacrylamide, its cationic density and interaction with soil particles can be significantly enhanced. 3-Chloro-2-hydroxypropyltrimethylammonium chloride is a cationic chemical reagent. Through nucleophilic substitution reaction, the chlorine atoms in the halogenated hydrocarbon react with the amine groups in the polyacrylamide molecular chain to form a quaternary ammonium salt structure. The quaternized polyacrylamide molecular chain has a higher cationic density, so it can form a stable composite interface with negatively charged soil particles, graphene oxide, phosphate groups and other polar components through electrostatic action. The introduction of the quaternary ammonium salt structure also makes polyacrylamide have stronger antibacterial properties, which can effectively inhibit the growth of microorganisms, thereby extending the service life of the soil stabilizer.

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

[0085] In order to further improve the performance of cationic polyacrylamide, the present invention introduces chitosan for modification. As a natural polysaccharide, chitosan has good biocompatibility and antibacterial properties. Its molecules contain abundant 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 protection 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 curing agent.

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

[0087] The present invention introduces bisphenol A epoxy resin, which contains epoxy groups and benzene ring structures in the epoxy resin molecules, giving it unique properties. The epoxy group is a functional group with high reactivity, which can react chemically with other reactive groups to form a cross-linked structure, thereby improving the overall strength and durability of the material. The high reactivity of the epoxy group 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 the benzene ring structure enhances the rigidity and chemical stability of the epoxy resin, so that it still maintains good heat resistance and anti-aging ability under high temperature and extreme environmental conditions. These characteristics make the bisphenol A epoxy resin have a wide range of applicability in the application fields requiring high strength, corrosion resistance and high temperature resistance.

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

[0089] In order to further enhance the acid and alkali resistance and durability of epoxy resin, the present invention introduces 1H, 1H, 2H, 2H-perfluorooctyl triethoxysilane to modify bisphenol A epoxy resin. The introduction of this chemical modifier introduces a CF bond structure into the epoxy resin molecule. The CF bond is a chemical bond with extremely high bond energy and very strong chemical stability, which enables the epoxy resin to exhibit excellent corrosion resistance when facing harsh environments such as acid and alkali media, oxidants, and solvents. The CF bond can not only significantly improve the acid and alkali resistance of the epoxy resin, but also enhance its aging resistance and high temperature resistance. In particular, the modified epoxy resin can maintain a longer service life when used for a long time or exposed to extreme conditions.

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

[0091] By blending with SBS block copolymers, the modified epoxy resin forms a microphase separation structure. The SBS block copolymer contains flexible polymer segments 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 maintains its rigidity and strength. This microphase separation structure gives the material excellent comprehensive properties, that is, the material has both good toughness and sufficient mechanical strength. The presence of the flexible phase enhances the ductility of the material, making it less likely to crack when impacted by external forces, while the hard phase provides higher compressive strength and tensile strength, allowing the material to withstand larger loads.

[0092] This microphase separation structure enables the modified epoxy resin to have excellent mechanical properties while maintaining flexibility and impact resistance, making it particularly suitable for use in complex soil curing environments. In these environments, soil curing agents need to simultaneously cope with multiple challenges such as geological vibrations, water penetration, and temperature fluctuations. 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 enhancement between these components effectively solves the problem of curing strength attenuation: 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. This cross-linked network significantly enhances the mechanical strength and durability of the curing system. The formation of ionic bonds not only increases the interaction between molecular chains, but also effectively improves the overall structure of the material, making it more stable under external forces; the active side chains formed by free radical polymerization during the acrylic acid grafting modification process can react with the epoxy groups in the epoxy resin to generate a stronger covalent cross-linked network. This covalent cross-linked structure greatly enhances the strength and chemical resistance of the curing system. During the cross-linking process, the active side chains can form strong chemical bonds with the epoxy groups, thereby improving the durability and crack resistance of the material.

[0094] Chitosan further strengthens the cross-linking degree of the network through the reaction of its amino group with the epoxy group in the epoxy resin molecule, forming a three-dimensional interpenetrating structure. This multiple cross-linked network structure can provide more stress transfer pathways for the material. Under stress conditions, the stress of the material can be shared among multiple cross-linked networks, thereby improving the toughness and impact resistance of its structure. When a part of the cross-linking bonds is broken, other cross-linked networks can take over the function of the broken part to ensure the overall strength and stability of the material, thereby significantly improving the stability and durability of the curing system under long-term load.

[0095] The phosphate group combines with the hydroxyl group in the starch ether molecule through hydrogen bonding, which enhances the interfacial compatibility between the two and improves the interfacial bonding force, thereby improving the structural stability and long-term durability of the curing system. The hydrogen bonding between the phosphate group and the hydroxyl group not only enhances the mutual adsorption between the two, but also makes the system show better corrosion resistance in a humid environment, further improving the adaptability of the material in a complex environment.

[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 reinforcing role in composite materials, especially in applications that require high structural stability.

[0097] The organic silicon group interacts with 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 affinity of the interface, but also enhances the water vapor barrier capacity of the material, which helps to improve the environmental resistance of the composite material.

[0098] The block copolymer forms a microphase separation structure of 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 strength required by the material; the high specific surface area and uniform distribution of nano-titanium dioxide can prevent crack propagation and provide an effective stress dispersion path, while also improving the mechanical properties of the material, enhancing its wear resistance and crack resistance; graphene oxide and polyacrylamide molecules form a conductive network, which helps to improve the mechanical properties and dispersion toughness of the material, thereby effectively extending the service life of the material. This optimized microstructure prevents crack propagation by providing a stress dispersion mechanism, improves the toughness of the material, and ensures the stability and reliability of the composite material in long-term use.

[0099] At the same time, there is also a synergistic enhancement effect to solve the poor acid and alkali resistance of the curing agent: after fluorination modification of bisphenol A epoxy resin, the CF bond introduced into the molecule has a higher bond energy and chemical stability, which makes the material show excellent corrosion resistance in acid and alkali media and reduces the damage of the acid and alkali environment to the material structure. The high chemical stability of the CF bond makes the modified epoxy resin extremely resistant to acid and alkali media, significantly improving the stability of the material in acidic or alkaline environments.

[0100] The silicone group reduces the affinity of the surface to acid and alkali solutions by increasing the hydrophobicity of the material surface, thereby reducing the penetration of acid and alkali solutions and improving the acid and alkali resistance of the material. The introduction of the silicone 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 solutions, further enhancing the durability and stability of the material.

[0101] The photocatalytic properties of titanium dioxide can decompose harmful substances in the air under ultraviolet light, and help decompose corrosive organic substances in acid-base environments, further protecting the material structure from chemical corrosion. Titanium dioxide not only has the ability to catalytically degrade harmful substances under ultraviolet light, but can also decompose corrosive substances through redox reactions in acid-base environments, reducing acid-base damage to materials and extending their service life.

[0102] The cationic groups in the quaternized polyacrylamide molecules can adjust the local pH value by interacting with the hydrogen ions or hydroxide ions in the acid-base medium, thereby maintaining the acid-base stability of the system. This regulatory effect enables the material to maintain a relatively stable internal environment in an acid-base environment, avoiding excessive interference of acid and alkali on the material properties, and improving the corrosion resistance and durability of the material.

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

[0104] The amino groups in chitosan can provide proton buffering by reacting with hydrogen ions or hydroxide ions in external acid-base media, thereby stabilizing the pH of the system and preventing excessive acid-base effects from damaging the material structure. The amino groups in chitosan react with external acid-base substances in an acid-base environment to provide proton buffering function, ensuring that the material can maintain good chemical stability under the action of external acid-base substances, further enhancing the durability of the material.

[0105] In a third aspect, the present invention provides a use of a liquid soil solidifier in a building foundation.

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

[0107] (1) The present invention introduces maleic anhydride-modified hydroxypropyl starch ether, whose polar groups and chemical activity enhance the binding force with soil particles, and introduces 2-acrylic acid to form a three-dimensional cross-linked network to significantly improve the water resistance, mechanical properties and environmental adaptability of the soil solidifier, thereby optimizing the soil solidification effect;

[0108] (2) Phosphate-modified nano-titanium dioxide and in-situ growth of graphene oxide on its surface significantly enhanced the material's dispersibility, interfacial bonding strength, and chemical stability, thereby optimizing the soil stabilizer's mechanical properties, durability, and adaptability and reliability in complex environments;

[0109] (3) The present invention modifies cationic polyacrylamide with 3-chloro-2-hydroxypropyltrimethylammonium chloride and chitosan to significantly improve its cationic density, antibacterial properties and durability, form an enhanced network structure and binding force with soil particles, thereby optimizing the compressive strength, durability, stability and adaptability of the soil solidifier in complex environments;

[0110] (4) The present invention introduces bisphenol A epoxy resin and performs fluorination modification on it and blends it with SBS to form a microphase 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 enhancement of multiple components, the present invention combines multiple cross-linked networks, interface enhancement mechanisms and acid and alkali resistance modification to significantly improve the mechanical properties, durability, corrosion resistance and environmental adaptability of the curing system, ensuring the long-term stability and reliability of the material under complex conditions;

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

[0113] Figure 1 A high-resolution transmission electron microscopy image of the modified nano-titanium dioxide provided in Example 1 of the present invention (scale: 50 nm);

[0114] Figure 2 This is a high-resolution transmission electron microscopy image of the modified nano-titanium dioxide provided in Example 1 of the present invention (scale: 20 nm). DETAILED DESCRIPTION

[0115] The technical solution of the present invention is described in detail below in conjunction with specific embodiments and their accompanying drawings. The embodiments recorded herein are specific embodiments of the present invention, which are used to illustrate the concept of the present invention; these descriptions are explanatory and exemplary and should not be construed as limitations on the embodiments of the present invention and the scope of protection of the present invention. In addition to the embodiments recorded herein, those skilled in the art can also adopt other obvious technical solutions based on the contents disclosed in the claims of this application and its specification, including technical solutions that adopt any obvious replacements and modifications to the embodiments recorded herein.

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

[0117] Example 1

[0118] This embodiment provides a liquid soil solidifier and a preparation method thereof, wherein the liquid soil solidifier comprises the following components in parts by weight:

[0119]

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

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

[0122] Specifically, 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.%, maleic anhydride in an amount of 5% of the mass of the hydroxypropyl starch ether is added under stirring, and the pH is adjusted to 5 with a 2M sodium hydroxide solution to obtain a reaction solution A, and the reaction solution A is poured into anhydrous ethanol for stirring and precipitation, suction filtration, and vacuum drying at 72°C to obtain maleic anhydride-modified hydroxypropyl starch ether; a maleic anhydride-modified hydroxypropyl starch ether solution with a mass fraction of 25wt.% is prepared, ammonium persulfate in an amount of 0.75% of the mass of the maleic anhydride-modified hydroxypropyl starch ether is added, and 2-acrylic acid in an amount of 5% of the mass of the maleic anhydride-modified hydroxypropyl starch ether is added dropwise under stirring to obtain a reaction solution B, and after constant temperature reaction at 50°C for 4h, reduced pressure distillation and freeze drying are performed to obtain modified hydroxypropyl starch ether;

[0123] S2: modifying nano-titanium dioxide with phosphate and then compounding it with graphene oxide to obtain modified nano-titanium dioxide;

[0124] Specifically, a nano titanium dioxide dispersion with a mass fraction of 8wt.% is prepared, and trisodium phosphate dodecahydrate is added in an amount of 5% of the mass of the nano titanium dioxide, and the mixture is reacted at a constant temperature of 45°C for 8 hours, followed by centrifugation, washing, and vacuum drying to obtain phosphate-modified titanium dioxide; a graphene oxide dispersion with a mass fraction of 0.5wt.% is prepared, and phosphate-modified titanium dioxide is added, wherein the amount of graphene oxide is 2.3% of the mass of the phosphate-modified titanium dioxide, and the mixture is stirred at 64°C for 13 hours, centrifuged, and vacuum dried to obtain modified nano titanium dioxide; Figure 1 , Figure 2 High-resolution transmission electron microscopy images of modified nano-titanium dioxide at different scales show that titanium dioxide grows in situ on the surface of graphene oxide.

[0125] S3: The polyacrylamide is modified by quaternization and then grafted with chitosan to obtain modified polyacrylamide;

[0126] Specifically, a cationic polyacrylamide dispersion with a mass fraction of 10wt.% is prepared, 3-chloro-2-hydroxypropyltrimethylammonium chloride is added in an amount of 15% of the mass of the cationic polyacrylamide, stirred at a constant temperature of 55°C for 10 hours under nitrogen protection, dialyzed, and freeze-dried 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 1.2wt.%, and 1-ethyl-(3-dimethylaminopropyl)carbodiimide hydrochloride is added Salt and N-hydroxysuccinimide are activated for 2 hours 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, a quaternized polyacrylamide solution is prepared and mixed with the reaction solution C to obtain reaction solution D, wherein the amount of chitosan added is 6% of the mass of the quaternized polyacrylamide, and the reaction is carried out at a constant temperature of 35° C. for 14 hours, dialyzed, and freeze-dried to obtain modified polyacrylamide;

[0127] S4: Compound-modifying bisphenol A epoxy resin with perfluoroalkyl silane and SBS block copolymer in sequence to obtain double-modified epoxy resin;

[0128] Specifically, a xylene solution of bisphenol A epoxy resin with a mass fraction of 35wt.% is prepared, 1H,1H,2H,2H-perfluorooctyltriethoxysilane in an amount of 5.6% of the mass of the bisphenol A epoxy resin is added, and refluxed at a constant temperature of 80°C for 4 hours and then distilled under reduced pressure to obtain a fluorinated epoxy resin; after the fluorinated epoxy resin is melted, an SBS block copolymer in an amount of 6% of the mass of the fluorinated epoxy resin is added, mechanically stirred at a speed of 500rpm for 2 hours under nitrogen protection, and crushed after cooling to obtain a double-modified epoxy resin;

[0129] 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.

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

[0131] Example 2

[0132] This embodiment provides a liquid soil solidifier and a preparation method thereof, wherein the liquid soil solidifier comprises the following components in parts by weight:

[0133]

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

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

[0136] Specifically, 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 with a mass fraction of 12wt.%, 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 solution A, and the reaction solution A is poured into anhydrous ethanol for stirring and precipitation, suction filtration, and vacuum drying at 78°C to obtain maleic anhydride-modified hydroxypropyl starch ether; a maleic anhydride-modified hydroxypropyl starch ether solution with a mass fraction of 28wt.% is prepared, ammonium persulfate in an amount of 0.5% of the mass of the maleic anhydride-modified hydroxypropyl starch ether is added, and 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 solution B, and after constant temperature reaction at 55°C for 3h, reduced pressure distillation and freeze drying are performed to obtain modified hydroxypropyl starch ether;

[0137] S2: modifying nano-titanium dioxide with phosphate and then compounding it with graphene oxide to obtain modified nano-titanium dioxide;

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

[0139] S3: The 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 12wt.% is prepared, 3-chloro-2-hydroxypropyltrimethylammonium chloride is added in an amount of 17% of the mass of the cationic polyacrylamide, stirred at a constant temperature of 58°C for 11 hours under nitrogen protection, dialyzed, and freeze-dried 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 1.5wt.%, and 1-ethyl-(3-dimethylaminopropyl)carbodiimide hydrochloride is 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, a quaternized polyacrylamide solution is prepared and mixed with the reaction solution C to obtain reaction solution D, wherein the amount of chitosan added is 5% of the mass of the quaternized polyacrylamide, and the reaction is carried out at a constant temperature of 40° C. for 16 hours, dialyzed, and freeze-dried to obtain modified polyacrylamide;

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

[0142] Specifically, a 32wt.% xylene solution of bisphenol A epoxy resin is prepared, 1H,1H,2H,2H-perfluorooctyltriethoxysilane is added in an amount of 5% of the mass of the bisphenol A epoxy resin, and the solution is refluxed at a constant temperature of 70°C for 3 hours and then distilled under reduced pressure to obtain a fluorinated epoxy resin; after the fluorinated epoxy resin is melted, an SBS block copolymer is added in an amount of 8% of the mass of the fluorinated epoxy resin, and the solution is mechanically stirred at a speed of 600 rpm for 3 hours under nitrogen protection, and then crushed after cooling 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 to anhydrous ethanol to obtain a mixture E with a solid content of 27wt.%, and modified nano titanium dioxide is added and ultrasonically dispersed to obtain a mixture F; after preheating the double-modified epoxy resin at 46°C, OP-10 with a feed amount of 3% of the mass of the epoxy resin and T31 curing agent with a feed amount of 12.5% ​​of the mass of the epoxy resin are added, and the mixture G is stirred to obtain a pretreated soil curing agent, and the mixture is added to the mixture F to obtain a pretreated soil curing agent, and high-speed shearing is carried out at a rotation speed of 5000rpm for 18min and vacuum degassing is carried out for 20min to obtain the liquid soil curing agent.

[0145] Example 3

[0146] This embodiment provides a liquid soil solidifier and a preparation method thereof, wherein the liquid soil solidifier comprises the following components in parts by weight:

[0147]

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

[0149] S1: modifying hydroxypropyl starch ether 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 with a mass fraction of 15wt.%, maleic anhydride in an amount of 7% of the mass of the hydroxypropyl starch ether is added under stirring, and the pH is adjusted to 6 with a sodium hydroxide solution with a concentration of 2.7M to obtain a reaction solution A, and the reaction solution A is poured into anhydrous ethanol for stirring and precipitation, suction filtration, and vacuum drying at 80°C to obtain maleic anhydride-modified hydroxypropyl starch ether; a maleic anhydride-modified hydroxypropyl starch ether solution with a mass fraction of 20wt.% is prepared, ammonium persulfate in an amount of 1% of the mass of the maleic anhydride-modified hydroxypropyl starch ether is added, and 2-acrylic acid in an amount of 10% of the mass of the maleic anhydride-modified hydroxypropyl starch ether is added dropwise under stirring to obtain a reaction solution B, and after constant temperature reaction at 45°C for 4.4h, reduced pressure distillation and freeze drying are performed to obtain modified hydroxypropyl starch ether;

[0151] S2: modifying nano-titanium dioxide with phosphate and then compounding it with graphene oxide to obtain modified nano-titanium dioxide;

[0152] Specifically, a nano titanium dioxide dispersion with a mass fraction of 10 wt.% is prepared, and trisodium phosphate dodecahydrate is added in an amount of 9% of the mass of the nano titanium dioxide, and the mixture is reacted at a constant temperature of 40°C for 7 hours, followed by centrifugation, washing, and vacuum drying to obtain phosphate-modified titanium dioxide; a graphene oxide dispersion with a mass fraction of 0.8 wt.% is prepared, and phosphate-modified titanium dioxide is added, wherein the amount of graphene oxide is 1% of the mass of the phosphate-modified titanium dioxide, and the mixture is stirred at 60°C for 14 hours, centrifuged, and vacuum dried to obtain modified nano titanium dioxide;

[0153] S3: The polyacrylamide is modified by quaternization and then grafted with chitosan to obtain modified polyacrylamide;

[0154] Specifically, a cationic polyacrylamide dispersion with a mass fraction of 14wt.% is prepared, 3-chloro-2-hydroxypropyltrimethylammonium chloride is added in an amount of 18% of the mass of the cationic polyacrylamide, stirred at a constant temperature of 60°C for 12h under nitrogen protection, dialyzed, and freeze-dried 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 1.3wt.%, and 1-ethyl-(3-dimethylaminopropyl)carbodiimide hydrochloride and N-hydroxysuccinimide and activated for 2.9 hours 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 quaternized polyacrylamide solution is prepared and mixed with reaction solution C to obtain reaction solution D, wherein the amount of chitosan is 4% of the mass of the quaternized polyacrylamide, and the reaction is carried out at a constant temperature of 45° C. for 12 hours, dialyzed, and freeze-dried to obtain modified polyacrylamide;

[0155] S4: Compound-modifying bisphenol A epoxy resin with perfluoroalkyl silane and SBS block copolymer in sequence to obtain double-modified epoxy resin;

[0156] Specifically, a 30wt.% xylene solution of bisphenol A epoxy resin is prepared, 1H,1H,2H,2H-perfluorooctyltriethoxysilane is added in an amount of 6% of the mass of the bisphenol A epoxy resin, and the solution is refluxed at a constant temperature of 75°C for 3.4 hours, and then distilled under reduced pressure to obtain a fluorinated epoxy resin; after the fluorinated epoxy resin is melted, an SBS block copolymer is added in an amount of 5% of the mass of the fluorinated epoxy resin, and the solution is mechanically stirred at a speed of 550rpm for 2.5 hours under nitrogen protection, and then crushed after cooling to obtain a double-modified epoxy resin;

[0157] 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.

[0158] Specifically, modified hydroxypropyl starch ether and modified polyacrylamide are added to anhydrous ethanol to obtain a mixture E with a solid content of 30wt.%, and modified nano titanium dioxide is added, and ultrasonic dispersion is performed to obtain a mixture F; after preheating the double-modified epoxy resin at 48°C, OP-10 in an amount of 5% of the mass of the epoxy resin and polyamide curing agent 650 in an amount of 15% of the mass of the epoxy resin are added, and the mixture G is stirred to obtain a pretreated soil curing agent, and the mixture is added to the mixture F to obtain a pretreated soil curing agent, and high-speed shearing is performed at a rotation speed of 3000rpm for 10min and vacuum degassing is performed for 25min to obtain the liquid soil curing agent.

[0159] Example 4

[0160] This embodiment provides a liquid soil solidifier and a preparation method thereof, wherein the liquid soil solidifier comprises the following components in parts by weight:

[0161]

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

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

[0164] Specifically, 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 14wt.%, maleic anhydride in an 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 sodium hydroxide solution with a concentration of 3M to obtain a reaction solution A, and the reaction solution A is poured into anhydrous ethanol for stirring and precipitation, suction filtration, and vacuum drying at 70°C to obtain maleic anhydride-modified hydroxypropyl starch ether; a maleic anhydride-modified hydroxypropyl starch ether solution with a mass fraction of 30wt.% is prepared, ammonium persulfate in an amount of 0.88% of the mass of the maleic anhydride-modified hydroxypropyl starch ether is added, and 2-acrylic acid in an amount of 7% of the mass of the maleic anhydride-modified hydroxypropyl starch ether is added dropwise under stirring to obtain a reaction solution B, and after constant temperature reaction at 52°C for 5h, reduced pressure distillation and freeze drying are performed to obtain modified hydroxypropyl starch ether;

[0165] S2: modifying nano-titanium dioxide with phosphate and then compounding it with graphene oxide to obtain modified nano-titanium dioxide;

[0166] Specifically, a nano titanium dioxide dispersion with a mass fraction of 7wt.% is prepared, and trisodium phosphate dodecahydrate is added in an amount of 10% of the mass of the nano titanium dioxide, and the mixture is reacted at a constant temperature of 50°C for 7.8h, centrifuged, washed, and vacuum dried to obtain phosphate-modified titanium dioxide; a graphene oxide dispersion with a mass fraction of 1wt.% is prepared, and phosphate-modified titanium dioxide is added, wherein the amount of graphene oxide is 2% of the mass of the phosphate-modified titanium dioxide, stirred at 70°C for 13.5h, centrifuged, and vacuum dried to obtain modified nano titanium dioxide;

[0167] S3: The polyacrylamide is modified by quaternization and then grafted with chitosan to obtain modified polyacrylamide;

[0168] Specifically, a cationic polyacrylamide dispersion with a mass fraction of 15wt.% is prepared, 3-chloro-2-hydroxypropyltrimethylammonium chloride is added in an amount of 20% of the mass of the cationic polyacrylamide, stirred at a constant temperature of 50°C for 11.5h under nitrogen protection, dialyzed, and freeze-dried 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 1wt.%, and 1-ethyl-(3-dimethylaminopropyl)carbodiimide hydrochloride is added and N-hydroxysuccinimide and activated for 3 hours to obtain reaction solution C, wherein 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 quaternized polyacrylamide solution is prepared and mixed with the reaction solution C to obtain a reaction solution D, wherein the amount of chitosan added is 3% of the mass of the quaternized polyacrylamide, and the reaction is carried out at a constant temperature of 42° C. for 15 hours, dialyzed, and freeze-dried to obtain modified polyacrylamide;

[0169] S4: Compound-modifying bisphenol A epoxy resin with perfluoroalkyl silane and SBS block copolymer in sequence to obtain double-modified epoxy resin;

[0170] Specifically, a 25wt.% xylene solution of bisphenol A epoxy resin was prepared, 1H,1H,2H,2H-perfluorooctyltriethoxysilane in an amount of 5.3% of the mass of the bisphenol A epoxy resin was added, and the solution was refluxed at a constant temperature of 76°C for 3.7 hours, and then distilled under reduced pressure to obtain a fluorinated epoxy resin; after the fluorinated epoxy resin was melted, an SBS block copolymer in an amount of 7% of the mass of the fluorinated epoxy resin was added, and the solution was mechanically stirred at a speed of 570rpm for 2.8 hours under nitrogen protection, and then crushed after cooling to obtain a double-modified epoxy resin;

[0171] 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.

[0172] Specifically, modified hydroxypropyl starch ether and modified polyacrylamide are added to anhydrous ethanol to obtain a mixture E with a solid content of 25wt.%, and modified nano titanium dioxide is added, and ultrasonic dispersion is performed to obtain a mixture F; after preheating the double-modified epoxy resin at 50°C, OP-10 with a feed amount of 4.2% of the mass of the epoxy resin and T31 curing agent with a feed amount of 14% of the mass of the epoxy resin are added, and the mixture G is stirred to obtain a pretreated soil curing agent, and the mixture is added to the mixture F to obtain a pretreated soil curing agent, and high-speed shearing is performed at a rotation speed of 4600rpm for 20min and vacuum degassing is performed for 28min to obtain the liquid soil curing agent.

[0173] Comparative Example 1

[0174] This comparative example provides a liquid soil solidifier, which is different from Example 1 in that, in step S1, the feeding amount of maleic anhydride is 15% of the mass of hydroxypropyl starch ether, and the other operating steps and process parameters are exactly the same as those in Example 1.

[0175] Comparative Example 2

[0176] This comparative example provides a liquid soil solidifier, which is different from Example 1 in that, in step S1, the feeding amount of maleic anhydride is 1% of the mass of hydroxypropyl starch ether, and the other operating steps and process parameters are exactly the same as those in Example 1.

[0177] Comparative Example 3

[0178] This comparative example provides a liquid soil curing agent, which is different from Example 1 in that, in step S4, the feeding amount of the 1H,1H,2H,2H-perfluorooctyltriethoxysilane is 10% of the mass of the bisphenol A epoxy resin, and the other operating steps and process parameters are exactly the same as those in Example 1.

[0179] Comparative Example 4

[0180] This comparative example provides a liquid soil curing agent, which is different from Example 1 in that, in step S4, the feeding amount of the 1H,1H,2H,2H-perfluorooctyltriethoxysilane is 1% of the mass of the bisphenol A epoxy resin, and the other operating steps and process parameters are exactly the same as those in Example 1.

[0181] The performance test of the liquid soil solidifiers of the above-mentioned Examples 1-4 and Comparative Examples 1-4 was carried out, and the specific process is as follows:

[0182] According to CJ / T 486-2015 "Soil Solidification Admixtures", the 7-day acid-alkali immersion and non-acid-alkali immersion unconfined compressive strength and the 28-day acid-alkali immersion and non-acid-alkali immersion unconfined compressive strength of the liquid soil solidifier obtained in Examples 1-4 and Comparative Examples 1-4 were tested;

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

[0184] Table 1: Performance test results of liquid soil solidifiers of Examples 1-4 and Comparative Examples 1-4

[0185]

[0186] It can be seen from Table 1 that the liquid soil solidifiers prepared in Examples 1-4 provided by the present invention have good unconfined compressive strength and acid and alkali resistance.

[0187] From the test results of Example 1 and Comparative Examples 1 and 2, it can be seen that 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 may lead to excessive cross-linking, making the material too brittle and reducing its ductility and flexibility; too little maleic anhydride cannot be fully cross-linked, resulting in an incomplete network structure of the modified product and insufficient performance.

[0188] From the test results of Example 1 and Comparative Examples 3 and 4, it can be seen that the appropriate dosage of 1H, 1H, 2H, 2H-perfluorooctyl triethoxysilane can improve the corrosion resistance and environmental adaptability of epoxy resin, which is very important for the long-term stability and durability of soil curing agent. When the dosage is too much, the epoxy resin is over-modified, so that the degree of fluorination of the resin is too high, resulting in reduced mechanical properties of the resin and increased brittleness; when the dosage is too little, the degree of fluorination of the epoxy resin is insufficient, resulting in incomplete fluorination modification effect, 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 curing agent in a complex environment.

[0189] The above description is only a specific implementation mode of the present invention, but the protection scope of the present invention is not limited thereto. Those skilled in the art should understand that any changes or substitutions that can be easily thought of by those skilled in the art within the technical scope disclosed by the present invention are within the protection scope and disclosure scope of the present invention.

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; S2: modifying nano-titanium dioxide with phosphate and then compounding it with graphene oxide to obtain modified nano-titanium dioxide; S3: The polyacrylamide is modified by quaternization and then grafted with chitosan to obtain modified polyacrylamide; S4: Compound-modifying bisphenol A epoxy resin with perfluoroalkyl silane and SBS block copolymer in sequence to obtain 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 curing agent and mixing evenly to obtain the liquid soil curing agent.

2. The method for preparing a liquid soil solidifier according to claim 1, characterized in that: In S1: The specific preparation method of the modified hydroxypropyl starch ether is as follows: dispersing hydroxypropyl starch ether in a methanol aqueous solution to obtain a hydroxypropyl starch ether dispersion, adding maleic anhydride under stirring and adjusting the pH with a sodium hydroxide solution to obtain a reaction solution A, pouring the reaction solution A into anhydrous ethanol to stir and 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 dropping 2-acrylic acid under stirring to obtain a reaction solution B, reacting at a constant temperature, performing reduced pressure distillation, and freeze drying to obtain the modified hydroxypropyl starch ether; 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 feeding amount of maleic anhydride is 3-8% of the mass of hydroxypropyl starch ether; 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 2, characterized in that: 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, characterized in that: In S2: The specific preparation method of modified nano titanium dioxide is as follows: prepare nano titanium dioxide dispersion, add trisodium phosphate dodecahydrate, react at constant temperature, centrifuge, wash, and vacuum dry to obtain phosphate-modified titanium dioxide; prepare graphene oxide dispersion, add phosphate-modified titanium dioxide, stir, centrifuge, and vacuum dry to obtain modified nano titanium dioxide; 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 6-8h.

5. The method for preparing a liquid soil solidifier according to claim 4, 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 specific preparation method of the modified polyacrylamide is as follows: 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 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 solution C, preparing a quaternary ammonium 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; 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 1-1.5wt.%; 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 quaternary ammonium polyacrylamide.

7. The method for preparing a liquid soil solidifier according to claim 1, characterized in that: In S4: The specific preparation method of the double-modified epoxy resin is as follows: prepare a bisphenol A type epoxy resin xylene solution, add 1H,1H,2H,2H-perfluorooctyltriethoxysilane, reflux at a constant temperature and then perform reduced pressure distillation to obtain a fluorinated epoxy resin; melt the fluorinated epoxy resin and then add the SBS block copolymer, mechanically stir under nitrogen protection, and crush after cooling to obtain a double-modified epoxy resin; The mass fraction of the bisphenol A epoxy resin acetone solution is 25-35wt.%; The feeding amount of the 1H,1H,2H,2H-perfluorooctyltriethoxysilane is 5-6% of the mass of the bisphenol A epoxy resin; 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: Specifically, the method comprises: 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 a 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, and high-speed shearing and vacuum degassing to obtain the liquid soil curing agent; The solid content of the mixture E is 20-30wt.%; The curing agent is polyamide curing agent 650 or T31 curing agent; The preheating temperature of the double-modified epoxy resin is 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 shearing is 3000-5000rpm; The high-speed shearing time of the pretreated 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 weight:

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

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