Water-based polyurethane-water-based epoxy resin composite modified cement-based grouting material with high impermeability and preparation process thereof

Abstract

The application discloses a water-based polyurethane-water-based epoxy resin composite modified cement-based grouting material with high anti-permeability and a preparation process thereof. Firstly, the water-based polyurethane and the water-based epoxy resin are premixed and homogenized; when the mass ratio of the two is 2:1, the best synergistic effect can be generated, and the slurry particle size is refined through electrostatic repulsion and steric hindrance effect; then, the composite emulsion is heat-activated and functional group-modified based on a curing agent, a defoaming agent and ammonia water; during the process, a dynamic dropping strategy considering rheological thermokinetics coupling is adopted to adapt to the change of reaction viscosity and eliminate bubbles; then, an interface coupling system is constructed based on a silane coupling agent, and the cement is subjected to high-speed shearing mixing and degassing treatment; finally, a dense organic-inorganic interpenetrating network structure is formed through curing. In this way, through the synergy of component proportion optimization and preparation process control, the problem of bubble residue caused by sudden increase of viscosity is solved, and the micro-density and interface bonding strength of the grouting material are improved.

Description

Technical Field

[0001] This application relates to the field of modified cement grout preparation, and more specifically, to a waterborne polyurethane-waterborne epoxy resin composite modified cement-based grouting material with high impermeability and its preparation process. Background Technology

[0002] In underground engineering, tunnel excavation, and nuclear waste disposal, the performance of grouting materials directly affects the safety and stability of projects facing complex hydrogeological conditions, especially in aquifers with well-developed microfractures. While traditional ordinary cement-based grouting materials are inexpensive and technologically mature, their ability to penetrate and diffuse in microfractures is limited by the coarse crystal size and porous structure of hardened cement. Furthermore, their impermeability coefficient after curing often fails to meet the sealing requirements under high water head pressure. In addition, the bonding force between ordinary cement grout and the bedrock interface is weak, and a loose, porous interface exists between cement hydration products and the bedrock, making it prone to debonding under long-term groundwater erosion, leading to leakage recurrence and sealing failure.

[0003] To overcome the shortcomings of single inorganic materials, introducing polymers to construct organic-inorganic interpenetrating networks is an effective technical approach. This structure, through the interpenetration and cross-linking of polymer segments within high-strength cement hydration products, significantly refines the pore structure. The flexibility and adhesiveness of the polymer synergistically enhance the material's density, impermeability, and interfacial bonding strength, thereby achieving efficient and durable sealing of micro-cracks. Waterborne polyurethane (WPU) possesses excellent flexibility and adhesiveness, but its strength is relatively low; waterborne epoxy resin (WEP) has high strength and corrosion resistance, but is relatively brittle. Modification with a single polymer cannot simultaneously meet the requirements of deep penetration, high-strength impermeability, and interfacial durability. Therefore, exploring the composite modification of WPU and WEP, especially investigating the microscopic synergistic mechanism of the two in the cement matrix at different mass ratios, is of great significance for the development of high-performance grouting materials. While existing research has touched upon this topic, it often lacks a systematic optimization of the relationship between the ratio of the two and the performance (such as the degree of particle size refinement, the rigid-flexible balance point, and the interfacial anchoring mechanism), resulting in the material performance failing to reach the theoretical optimal value. For example, it is impossible to accurately achieve the ultrafine particle size (such as 5μm) required for the diffusion of microcracks by adjusting the ratio.

[0004] Furthermore, even if the optimal blending ratio of WPU and WEP is determined, successfully constructing a dense organic-inorganic interpenetrating network structure still highly depends on the refinement of the preparation process. Existing simplified mixing processes often neglect the activation of polymer precursors and the construction of the interfacial chemical environment, resulting in poor compatibility between the organic and inorganic phases. Conventional static feeding methods often fail to adapt to changes in reaction viscosity, leading to residual bubbles. These crude process practices ultimately result in microscopic defects in the otherwise dense interpenetrating network, severely limiting the achievement of high impermeability of the optimized formulation in practical engineering applications.

[0005] Therefore, an optimized preparation process for modified cement-based grouting materials is desired. Summary of the Invention

[0006] To address the aforementioned technical problems, this application is proposed. Embodiments of this application provide a waterborne polyurethane-waterborne epoxy resin composite modified cement-based grouting material with high impermeability and its preparation process.

[0007] According to one aspect of this application, a process for preparing a waterborne polyurethane-waterborne epoxy resin composite modified cementitious grouting material with high impermeability is provided, comprising:

[0008] Waterborne polyurethane and waterborne epoxy resin are premixed and homogenized to obtain a composite emulsion.

[0009] Based on curing agent, defoamer and ammonia, the composite emulsion is thermally activated and functional group modified to obtain activated polymer precursor;

[0010] An improved aqueous solution was obtained by constructing an interfacial coupling system for activated polymer precursors based on deionized water and silane coupling agents.

[0011] A fresh composite modified slurry was obtained by solid-liquid mixing, high-speed shearing, and homogenization dispersion of an improved aqueous solution and ordinary silicate cement.

[0012] Fresh composite modified grout is densified and cured to obtain a waterborne polyurethane-waterborne epoxy resin composite modified cement-based grouting material with high impermeability.

[0013] According to another aspect of this application, a waterborne polyurethane-waterborne epoxy resin composite modified cement-based grouting material with high impermeability is provided, wherein the waterborne polyurethane-waterborne epoxy resin composite modified cement-based grouting material with high impermeability is prepared by a process for preparing waterborne polyurethane-waterborne epoxy resin composite modified cement-based grouting materials with high impermeability.

[0014] Compared with existing technologies, this application provides a waterborne polyurethane-waterborne epoxy resin composite modified cement-based grouting material with high impermeability and its preparation process. Firstly, through systematic research, the optimal synergistic effect of waterborne polyurethane and waterborne epoxy resin at a mass ratio of 2:1 was determined, clarifying the technical path to achieve ultrafine particle size and a balance between rigidity and flexibility by utilizing the advantages of this formulation. To ensure that the theoretical performance of this optimized formulation is realized in actual preparation, this process constructs a full-process control scheme from precursor activation to interface system construction: in the thermal activation stage, an adaptive dripping mechanism is introduced to eliminate bubble defects by addressing the viscosity coupling effect; in the precursor treatment stage, a silane coupling agent is used to graft pre-set molecular bridges to solve compatibility issues; finally, high-speed shearing and negative pressure degassing achieve highly dense curing and molding. This scheme integrates the material science optimization of component ratios with the process science precision control of the preparation process from the source, effectively solving the problems of poor permeability, weak interfacial bonding, and insufficient impermeability caused by imprecise formulations and rough processes in traditional schemes. Attached Figure Description

[0015] The above and other objects, features, and advantages of this application will become more apparent from the more detailed description of the embodiments of this application in conjunction with the accompanying drawings. The drawings are provided to further illustrate the embodiments of this application and form part of the specification. They are used together with the embodiments of this application to explain this application and do not constitute a limitation thereof. In the drawings, the same reference numerals generally represent the same components or steps.

[0016] Figure 1 This is a flowchart illustrating the preparation process of a waterborne polyurethane-waterborne epoxy resin composite modified cementitious grouting material with high impermeability according to embodiments of this application.

[0017] Figure 2 This is a flowchart illustrating the process of preparing a waterborne polyurethane-waterborne epoxy resin composite modified cementitious grouting material with high impermeability according to an embodiment of this application, which involves thermally activating and functionalizing a composite emulsion with a curing agent, defoamer, and ammonia to obtain an activated polymer precursor.

[0018] Figure 3 The flowchart illustrates the process of preparing a waterborne polyurethane-waterborne epoxy resin composite modified cementitious grouting material with high impermeability according to embodiments of this application. It describes the process of adding curing agent and defoamer to the reaction container using a dropper to ensure uniform dispersion of the curing agent to initiate the ring-opening reaction of the epoxy functional groups in the waterborne epoxy resin, while the defoamer inhibits the generation of bubbles during the process.

[0019] Figure 4This is a data flow diagram illustrating the process of preparing a waterborne polyurethane-waterborne epoxy resin composite modified cement-based grouting material with high impermeability according to an embodiment of this application. The process involves using a dropper to add curing agent and defoamer to a reaction vessel to ensure uniform dispersion of the curing agent to initiate the ring-opening reaction of the epoxy functional groups in the waterborne epoxy resin, while the defoamer inhibits the generation of bubbles during the process.

[0020] Figure 5 This is a flowchart illustrating the process of densifying and curing a fresh composite modified grout to obtain a waterborne polyurethane-waterborne epoxy resin composite modified cementitious grouting material with high impermeability according to embodiments of this application.

[0021] Figure 6 This is a microstructure diagram of polymer-modified hardened cement slurry.

[0022] Figure 7 This is a diagram showing the pore structure and impermeability coefficient of polymer-modified materials.

[0023] Figure 8 This is a diagram illustrating the chemical and physical modification mechanisms of WPU-WEP composite materials. Detailed Implementation

[0024] Hereinafter, exemplary embodiments according to this application will be described in detail with reference to the accompanying drawings. Obviously, the described embodiments are merely some embodiments of this application, and not all embodiments of this application. It should be understood that this application is not limited to the exemplary embodiments described herein.

[0025] As indicated in this application and claims, unless the context clearly indicates otherwise, the words "a," "an," "an," and / or "the" are not specifically singular and may include plural forms. Generally speaking, the terms "comprising" and "including" only indicate the inclusion of explicitly identified steps and elements, which do not constitute an exclusive list, and the method or apparatus may also include other steps or elements.

[0026] While this application makes various references to certain modules of the systems according to embodiments of this application, any number of different modules can be used and run on user terminals and / or servers. The modules described are merely illustrative, and different aspects of the systems and methods may use different modules.

[0027] Flowcharts are used in this application to illustrate the operations performed by the system according to embodiments of this application. It should be understood that the preceding or following operations are not necessarily performed in exact order. Instead, various steps can be processed in reverse order or simultaneously as needed. Furthermore, other operations can be added to these processes, or one or more steps can be removed from them.

[0028] Hereinafter, exemplary embodiments according to this application will be described in detail with reference to the accompanying drawings. Obviously, the described embodiments are merely some embodiments of this application, and not all embodiments of this application. It should be understood that this application is not limited to the exemplary embodiments described herein.

[0029] To address the issues of microcrack sealing failure caused by coarse particle size and weak interfacial bonding in traditional cement grouting materials, and the limited material performance due to insufficient proportion optimization and crude preparation processes (such as insufficient activation and residual bubbles) in existing WPU-WEP modification schemes, this application proposes a preparation process for a waterborne polyurethane-waterborne epoxy resin composite modified cement-based grouting material with high impermeability. This scheme first utilizes the synergistic effect of waterborne polyurethane and waterborne epoxy resin at a specific mass ratio (2:1) to achieve micron-level refinement of slurry particle size through electrostatic repulsion and steric hindrance mechanisms. Subsequently, in the preparation process, the composite emulsion undergoes precise thermal activation and functional group modification. During this process, rheological thermodynamics feedback is used to dynamically control the feeding to eliminate microbubbles, and further, an organic-inorganic interface chemical bonding system is constructed using a silane coupling agent. Finally, through high-speed shear dispersion and structural densification treatment, the modified components and cement hydration products form a defect-free, highly dense interpenetrating network structure in situ, thereby obtaining a grouting material with superior impermeability and interfacial bonding properties. Notably, current grouting material design standards typically require a permeability coefficient of less than 1 x 10⁻⁶. -9 A permeability coefficient of m / s is generally considered to indicate impermeability. In this design, however, high impermeability refers to a permeability coefficient reduced to 10. -11 m / s.

[0030] Figure 1 This is a flowchart illustrating the preparation process of a waterborne polyurethane-waterborne epoxy resin composite modified cementitious grouting material with high impermeability according to embodiments of this application. Figure 1As shown, the preparation process of the waterborne polyurethane-waterborne epoxy resin composite modified cement-based grouting material with high impermeability according to an embodiment of this application includes the following steps: S100, premixing and homogenizing waterborne polyurethane and waterborne epoxy resin to obtain a composite emulsion; S200, thermally activating and functionalizing the composite emulsion based on a curing agent, defoamer, and ammonia to obtain an activated polymer precursor; S300, constructing an interfacial coupling system for the activated polymer precursor based on deionized water and a silane coupling agent to obtain an improved aqueous solution; S400, mixing the improved aqueous solution and ordinary silicate cement in a solid-liquid manner, performing high-speed shearing, and homogenizing dispersion to obtain a fresh composite modified slurry; S500, densifying and curing the fresh composite modified slurry to obtain the waterborne polyurethane-waterborne epoxy resin composite modified cement-based grouting material with high impermeability.

[0031] Specifically, in step S100, waterborne polyurethane and waterborne epoxy resin are premixed and homogenized to obtain a composite emulsion. It should be understood that since waterborne polyurethane and waterborne epoxy resin are polymer dispersions with different properties, if they are not uniformly blended at the microscale before entering the subsequent chemical reaction stage, phase separation or uneven distribution of reactive centers can easily occur due to differences in interfacial tension, severely damaging the structural integrity of the organic-inorganic interpenetrating network. Therefore, in the technical solution of this application, by premixing and homogenizing waterborne polyurethane and waterborne epoxy resin to obtain a composite emulsion, the agglomeration state of the original dispersion units is broken through physical shearing, promoting the molecular or colloidal interpenetration and fusion of the two polymer particles in the liquid phase. This constructs a thermodynamically stable and uniformly composed reaction matrix, effectively eliminating local concentration gradients and providing a consistent material basis for subsequent ring-opening polymerization and in-situ crosslinking with cement hydration products, thereby ensuring that the final cured slurry possesses excellent mechanical properties and durability.

[0032] More specifically, in this embodiment, the premixing and homogenization of waterborne polyurethane and waterborne epoxy resin to obtain a composite emulsion includes: injecting waterborne polyurethane and waterborne epoxy resin into a mixing container according to a preset mass ratio; placing the mixing container at ambient temperature and starting a stirring device to continuously stir for 5 minutes to obtain the composite emulsion. More specifically, in a specific example of this application, the premixing and homogenization step follows a strict physical blending process. First, the operator accurately weighs the waterborne polyurethane emulsion and the waterborne epoxy resin emulsion according to a pre-set process formula, and injects them sequentially into a clean mixing container according to a predetermined mass ratio (e.g., 2:1) to ensure the accuracy of the initial material ratio. It is worth mentioning that the ratio of waterborne polyurethane (WPU) to waterborne epoxy resin (WEP) is chosen here because at a 2:1 ratio, the flexible segments of WPU and the rigid network of WEP achieve optimal performance synergy. On the one hand, the complementary steric hindrance and electrostatic repulsion effects of the two components refine the slurry particle size to a minimum (5.12 μm), greatly enhancing the material's ability to penetrate microcracks. On the other hand, the organic-inorganic interpenetrating network structure formed at this ratio is the densest and achieves a balance between rigidity and flexibility. While improving compressive strength, it significantly enhances interfacial bonding through a dual mechanism of chemical anchoring and stress buffering. Subsequently, the mixing container was placed under controlled ambient temperature conditions (e.g., 25 degrees Celsius) to maintain the rheological stability of the emulsion system and avoid the impact of temperature fluctuations on the emulsion particle size. Finally, a stirring device equipped with a mechanical stirring paddle was started, a constant stirring rate (e.g., 300 rpm) was set, and stirring was continued for 5 minutes. The shear force field generated by mechanical energy forced the two-phase fluids to undergo convective and diffusion mixing until the mixture reached a homogeneous state, thus obtaining a composite emulsion that meets the requirements of subsequent reactions.

[0033] Specifically, in step S200, the composite emulsion is thermally activated and functionalized using a curing agent, defoamer, and ammonia to obtain an activated polymer precursor. It should be understood that since the polymer molecular chains in the mixed composite emulsion are still in a relatively inert physical stacking state, and the epoxy functional groups in the waterborne epoxy resin, without chemical activation, are difficult to form efficient chemical covalent bonds with the cement matrix during subsequent hydration, thus preventing molecular-level interpenetration between the organic and inorganic phases. Therefore, in the technical solution of this application, the composite emulsion is further thermally activated and functionalized using a curing agent, defoamer, and ammonia to obtain an activated polymer precursor. This allows for the activation of reactant molecules through thermal kinetic energy and the forced ring-opening of epoxy groups initiated by the curing agent, thereby pre-constructing preliminary crosslinking sites and active reactive groups in the liquid phase system. This significantly enhances the chemical integration capability of polymer segments, while utilizing the pH adjustment effect of ammonia to maintain the colloidal stability of the emulsion system during the reaction process. In addition, the defoamer eliminates structural internal stress defects caused by viscosity climb, providing highly reactive in-situ modification units for the subsequent formation of a crack-free, highly dense organic-inorganic interpenetrating network structure.

[0034] Figure 2 This is a flowchart illustrating the preparation process of a waterborne polyurethane-waterborne epoxy resin composite modified cementitious grouting material with high impermeability according to embodiments of this application. The process involves thermal activation and functional group modification of the composite emulsion using a curing agent, defoamer, and ammonia to obtain an activated polymer precursor. Figure 2 As shown, step S200 includes: S210, transferring the composite emulsion to the reaction vessel and then turning on the water bath for heating; S220, using a dropper to add curing agent and defoamer to the reaction vessel, ensuring that the curing agent is evenly dispersed to initiate the ring-opening reaction of the epoxy functional groups in the waterborne epoxy resin, while the defoamer inhibits the generation of bubbles during the process; S230, gradually adding ammonia water during the reaction until the pH value stabilizes at around 7.

[0035] In step S210, the composite emulsion is transferred to the reaction vessel and then heated in a water bath. It should be understood that, due to the low kinetic potential energy of polymer molecular chain segments at room temperature, and the need to overcome a specific activation energy barrier for the subsequent ring-opening reaction of epoxy groups initiated by the curing agent to be effectively started, the chemical modification process will be extremely slow or even difficult to occur without a uniform external heat supply. Therefore, in the technical solution of this application, the composite emulsion is further transferred to the reaction vessel and then heated in a water bath to create a constant and mild thermal reaction environment for the emulsion system. This utilizes heat conduction to increase the intensity of Brownian motion of reactant molecules and provides the thermodynamic conditions required to overcome the reaction energy barrier. This ensures that the subsequent functional group modification reaction is initiated efficiently and stably within a preset temperature window. Simultaneously, the water bath heating mode effectively avoids the risks of localized overheating and demulsification or polymer charring that may result from direct heating, ensuring the thermal stability of the precursor preparation process.

[0036] In a specific example of this application, firstly, the operator uses a liquid transfer device to transfer the composite emulsion prepared in the upstream process non-destructively into the clean interior of a three-necked glass reaction vessel, ensuring complete material transfer without residue. Subsequently, the reaction vessel is securely placed in the heating bath of a constant-temperature water bath, and the immersion depth is adjusted so that the liquid level inside the vessel is lower than the water bath medium level to maximize the heat exchange area. Finally, the heating control unit of the water bath is activated, and the target process temperature is set to 50 degrees Celsius. The water bath medium is gradually heated and heat is transferred to the composite emulsion through the vessel walls until the system temperature inside the reaction vessel reaches and stabilizes at the set reaction temperature, preparing the thermodynamics for subsequent reagent addition.

[0037] Specifically, in thermally activated systems, the curing agent is a key reactant initiating the ring-opening reaction of epoxy functional groups in waterborne epoxy resins. Its addition method directly determines the polymerization rate, exothermic intensity, and viscosity evolution curve of the system. Simultaneously, mechanical stirring and chemical reactions inevitably introduce or generate bubbles. If not eliminated promptly, these bubbles will be permanently sealed by the cured, high-viscosity matrix, forming microstructural defects. Therefore, in step S220, a dripper is used to add the curing agent and defoamer to the reaction vessel, ensuring uniform dispersion of the curing agent to initiate the ring-opening reaction of epoxy functional groups in the waterborne epoxy resin, while the defoamer suppresses bubble formation during the process. By using a slow and continuous feeding method, the reaction process is smoothly controlled, avoiding localized instantaneous gelation and hot spot runaway caused by excessively rapid feeding, and simultaneously breaking dynamically generated bubbles in situ. This ensures that the polymerization reaction proceeds homogeneously and controllably throughout the entire liquid phase volume, providing a process guarantee for preparing activated polymer precursors without internal defects and with uniform structure.

[0038] In a specific example of this application, the operator first loads the measured curing agent and defoamer into separate constant-pressure dropping funnels or feed lines driven by peristaltic pumps, precisely targeting the feed inlets of the reaction vessel. Then, a fixed, empirically based dropping rate is set according to the process specifications, for example, 2 ml per minute, and the dropping program for both the curing agent and defoamer is simultaneously initiated. Throughout the dropping process, this dropping rate remains constant and is not adjusted based on the actual state of the system within the reaction vessel (such as changes in viscosity, temperature, or foam volume). The operator continuously stirs the mixture to assist in the mechanical diffusion of the reagents within the composite emulsion until the predetermined total amount of curing agent and defoamer has been added, thus completing this step.

[0039] It is understandable that in the preparation process of waterborne polymer composite modified cement paste, the thermal activation and functional group modification process in the above embodiments adopts an open-ring, static droplet control method, that is, adding curing agent and defoamer at a fixed, slow rate. This method ignores the complex and dynamic coupling relationship between rheology, thermodynamics, and mass transfer within the reaction system. Specifically, the addition of the curing agent triggers the ring-opening polymerization of the waterborne epoxy resin, which is an exothermic process accompanied by a rapid, nonlinear increase in the system viscosity. The increase in viscosity significantly enhances the strength and surface tension of the bubble liquid film, making the foam more stable and difficult to break. At this point, if the defoamer is still added at the initial constant rate, its diffusion and migration ability in the viscous medium will decrease significantly, resulting in a sharp reduction in defoaming efficiency. At the same time, the stirring paddle operates in a system transitioning from a Newtonian fluid to a non-Newtonian fluid, and its shear stress field will change, thereby altering the bubble formation mode and rate, which the fixed droplet strategy cannot dynamically match. This mismatch between the reaction state and the control method ultimately leads to a large number of microbubbles remaining inside the slurry, damaging the density and integrity of the organic-inorganic interpenetrating network structure, thereby affecting the macroscopic properties of the final material. Based on this, a preferred embodiment of this application proposes an adaptive dripping control mechanism based on rheological-thermodynamic coupling. The core of this mechanism lies in changing open-loop control to closed-loop feedback control. By sensing the multidimensional state of the reaction system in real time and using a data model to calculate the optimal dripping strategy, precise and dynamic control of the flow rates of the curing agent and defoamer can be achieved.

[0040] Specifically, in another specific example of this application, Figure 3 This document describes a process for preparing a waterborne polyurethane-waterborne epoxy resin composite modified cementitious grouting material with high impermeability according to embodiments of this application. The process involves using a dropper to add a curing agent and a defoamer to a reaction vessel, ensuring uniform dispersion of the curing agent to initiate the ring-opening reaction of the epoxy functional groups in the waterborne epoxy resin, while simultaneously using the defoamer to suppress bubble formation during the process. Figure 4This diagram illustrates the data flow of a process for preparing a waterborne polyurethane-waterborne epoxy resin composite modified cementitious grouting material with high impermeability according to an embodiment of this application. It shows the use of a dropper to add a curing agent and a defoamer to a reaction vessel, ensuring uniform dispersion of the curing agent to initiate the ring-opening reaction of the epoxy functional groups in the waterborne epoxy resin, while simultaneously using the defoamer to suppress bubble formation during the process. Figure 3 and Figure 4 As shown, step S220 includes: S221, acquiring real-time stirring torque, real-time system temperature, and emulsion level; S222, performing multi-dimensional sensing of the reaction rheological state and foam characteristics of the real-time stirring torque, real-time system temperature, and emulsion level to obtain reaction kinetic indices and foam retention indices; S223, performing a dripping strategy calculation based on viscosity coupling compensation on the reaction kinetic indices and foam retention indices to obtain the target flow rate of the curing agent and the target flow rate of the defoamer; S224, performing pulse width modulation control of the actuators on the target flow rates of the curing agent and the defoamer to obtain the control signals for the curing agent pump and the defoamer pump. In this way, by intelligently controlling the curing agent flow rate, the problems of localized gelation and uneven curing caused by reaction runaway can be effectively avoided. Furthermore, by introducing an innovative viscosity coupling compensation model, the persistent problem of low defoaming efficiency caused by increased viscosity in the later stages of the reaction in traditional processes is fundamentally solved, ensuring the complete elimination of microbubbles inside the slurry.

[0041] Accordingly, in steps S221 and S222, real-time stirring torque, real-time system temperature, and emulsion level are acquired, and the reaction rheological state and foam characteristics of the real-time stirring torque, real-time system temperature, and emulsion level are multi-dimensionally perceived to obtain reaction kinetic indices and foam retention indices. It should be understood that to achieve intelligent control of complex chemical reactions, it is necessary to first establish a real-time, quantitative understanding of the internal state of the reaction process to replace fuzzy judgments relying on experience. Traditional open-loop control is completely blind to this process and cannot perceive the dynamic evolution of viscosity, temperature, and foam. Therefore, in the technical solution of this application, by acquiring real-time stirring torque, real-time system temperature, and emulsion level, and performing multi-dimensional perception of the reaction rheological state and foam characteristics of the real-time stirring torque, real-time system temperature, and emulsion level to obtain reaction kinetic indices and foam retention indices, a digital twin model that can accurately map the internal physicochemical changes of the reaction is constructed through the fusion of multi-source heterogeneous data streams. In this way, the ambiguous production process can be digitized and made transparent, providing accurate and reliable decision-making basis for subsequent closed-loop feedback control. Among them, the reaction kinetic index can serve as the system's early warning radar, capturing the precursors of the gelation point in advance, while the foam retention index provides the system with an objective basis for judging the severity of the foam crisis.

[0042] Specifically, in one particular example of this application, the multidimensional sensing process is implemented through an integrated sensing and computing system. First, a high-precision torque sensor is integrated onto the drive shaft of the agitator in the reaction vessel, a thermocouple temperature sensor is immersed inside the vessel, and a non-contact liquid level sensor is deployed directly above the top of the vessel. These sensors continuously collect three types of key data streams: real-time stirring torque characterizing changes in system viscosity, real-time system temperature reflecting the exothermic polymerization reaction, and emulsion level height quantifying the foam formation volume. The collected raw data is then fed into a data processing module, which transforms it into more informative higher-order state indices. This module first calculates reaction kinetic indices. This calculation incorporates the rate of change of torque and temperature to characterize the intensity of the current polymerization reaction and the rate of viscosity rise, as shown below:

[0043]

[0044] in, The reaction kinetic index at time t; For real-time stirring torque; This refers to the real-time system temperature. and This is an adjustable weighting factor. It quantifies the instantaneous rate of the polymerization reaction by weighted summation of the first derivatives of torque and temperature with respect to time, a rapidly increasing [factor / value]. The value indicates that the reaction is approaching runaway or is about to enter the gelation stage, providing a window for early intervention by the control system.

[0045] At the same time, this module calculates the foam retention index. By normalizing the difference between the current liquid level and the theoretical liquid level, a quantitative assessment of the severity of foaming is achieved, as shown below:

[0046]

[0047] in, Let be the bubble retention index at time t; Let be the emulsion level height at time t; The theoretical liquid level at time t, based on the amount of material added, is the ideal, foam-free liquid level calculated in real time based on the initial liquid volume and the volumes of curing agent and defoamer added up to time t. This formula transforms the absolute change in foam volume into a relative indicator, eliminating the influence of the material addition process on the liquid level baseline. This accurately reflects the net generation and retention of foam, providing a direct quantitative input for defoamer dosing strategies.

[0048] Accordingly, in step S223, a dripping strategy based on viscosity coupling compensation is performed on the reaction kinetic index and the foam retention index to obtain the target flow rates of the curing agent and the defoamer. It should be understood that simple linear feedback control cannot resolve the conflicting objectives of reaction promotion and foam suppression, especially since the attenuation effect of increased viscosity on defoaming efficiency must be considered in the algorithm. Otherwise, in the later stages of the reaction, the fixed control strategy will fail because it cannot compensate for the loss of diffusion efficiency of the defoamer. Therefore, in the technical solution of this application, a dripping strategy based on viscosity coupling compensation is further performed on the reaction kinetic index and the foam retention index to obtain the target flow rates of the curing agent and the defoamer, thereby constructing a nonlinear, multivariable control model. This model can dynamically balance the relationship between the reaction rate and foam generation based on the real-time state of the reaction and actively compensate for the mismatch of control parameters caused by changes in rheological properties. In this way, a dynamic and optimal feeding curve can be generated through the algorithm, which fundamentally solves the quality defects caused by control lag and model lack in traditional processes, ensures that the polymerization reaction proceeds smoothly and uniformly, and maintains efficient foam breaking ability, thus providing the possibility of preparing materials with dense and flawless microstructure.

[0049] Specifically, in a concrete example of this application, the solution for the dropping strategy is executed within a strategy solution engine. The reaction kinetics indicators output from the previous step... Foam retention index and real-time torque as a viscosity proxy value These values ​​are input into the engine. The engine calculates the optimal target flow rates for the curing agent and defoamer using the following two core formulas. Curing agent target flow rate The calculation employs reverse inhibition logic, which automatically reduces the feeding rate when the reaction becomes too vigorous, as shown below:

[0050]

[0051] in, Let be the target flow rate of the curing agent at time t; Based on the flow rate; It is an inhibitory factor; This is a preset kinetic index threshold. The formula acts like a reaction brake, adjusting the kinetic index accordingly. Exceeding the preset threshold At this time, the exponential term in the denominator will increase sharply, causing the target flow rate of the curing agent to decrease. Rapid decay allows for proactive intervention to slow the reaction rate, ensuring that the polymerization reaction proceeds smoothly and uniformly within a controllable range, preventing localized overheating or instantaneous gelation.

[0052] The target flow rate of the defoamer The calculation introduces a viscosity compensation term, which uses an exponential function to simulate and compensate for the loss of defoaming efficiency caused by the increase in viscosity, as follows:

[0053]

[0054] in, Let be the target flow rate of the defoamer at time t; Basic response coefficient; This is the viscosity compensation coefficient; This is the viscosity proxy value, i.e., the real-time stirring torque. This formula directly addresses the technical pain point, as its defoamer flow rate is not only related to the foam retention index... Proportional, and further compensated by an exponential term driven by real-time torque. This means that as the system becomes viscous (torque increases), the amount of defoamer added increases exponentially. By increasing the penetration of the defoamer, the diffusion resistance caused by the high viscosity medium is offset, thus maintaining a high level of foam breaking ability even when the system becomes viscous in the later stages of the reaction.

[0055] Accordingly, in step S224, the target flow rates of the curing agent and defoamer are subjected to pulse width modulation (PWM) control of the actuator to obtain the curing agent pump control signal and the defoamer pump control signal. It should be understood that since the fine control strategy generated by the algorithm must be translated into reality through high-precision physical execution, the target flow rates of the curing agent and defoamer calculated in the previous step are continuous digital signals, while the actuator responsible for transporting the liquid, such as a peristaltic pump, is controlled by discrete electrical signals. If the continuous intent of the algorithm cannot be accurately translated into physical execution, the superiority of the algorithm will not be realized. Therefore, in the technical solution of this application, the target flow rates of the curing agent and defoamer are further subjected to PWM control of the actuator to obtain the curing agent pump control signal and the defoamer pump control signal, thereby establishing a precise mapping from the digital domain to the physical domain, transforming the abstract flow rate command into a specific PWM duty cycle that can be recognized and executed by the motor. This ensures that the physical execution layer can faithfully reproduce the nonlinear control intent of the algorithm. Through high-precision execution capabilities, the entire adaptive control strategy is implemented, ensuring the integrity and effectiveness of the entire closed-loop control chain from perception and decision-making to execution. Ultimately, the algorithm's advantages are transformed into product quality advantages.

[0056] Specifically, in one particular example of this application, the control execution process is performed by a microcontroller unit. The continuous target flow velocity signal calculated in the previous policy calculation engine... and It is converted in real time into a pulse width modulation duty cycle signal to drive precision metering equipment such as peristaltic pumps. , means as follows:

[0057]

[0058] in, Let t be the pump's output duty cycle. The target flow velocity at time t (corresponding to) or ); This is the pump's displacement per revolution, a calibrated inherent parameter of the equipment. This is the pump's maximum rotational speed. The core of this formula lies in converting a physical quantity (target flow velocity) into the pump's maximum rotational speed. ) and the pump's theoretical maximum delivery capacity ( The comparison is performed, and the ratio is directly mapped to the duty cycle of the PWM signal. For example, when the algorithm requires a maximum flow rate of 50%, the controller outputs a square wave signal with a 50% duty cycle, driving the pump motor to operate for half the time, thus accurately achieving the target flow rate. The min function ensures that the calculated duty cycle does not exceed 100%, acting as hardware protection. Finally, the microcontroller generates two independent PWM signals, which serve as the control signals for the curing agent pump and the defoamer pump, respectively, and send them to the drive circuits of their respective pumps, thereby faithfully executing every dynamic feeding command issued by the upper-level algorithm with extremely high resolution and response speed.

[0059] Through the above preferred embodiments, this adaptive control mechanism upgrades the static dripping process, which originally relied on manual experience, into an intelligent, closed-loop feedback control system based on multi-source data fusion and model prediction. Its core technical objective is to precisely regulate the microenvironment of the organic-inorganic interpenetrating network during its formation process through real-time sensing and dynamic response, thereby obtaining a denser, more uniform, and defect-free material microstructure. The mechanism's technical effects are significant. It not only effectively avoids localized gelation and uneven curing caused by reaction runaway by intelligently controlling the curing agent flow rate, but more importantly, by introducing a viscosity coupling compensation model, it fundamentally solves the persistent problem of low defoaming efficiency caused by increased viscosity in the later stages of the reaction in traditional processes. Ultimately, this refined process control ensures the complete elimination of microbubbles within the slurry, significantly improving the microscopic integrity and batch stability of the final cured product, and thus enhancing the material's key macroscopic properties such as impermeability and compressive strength.

[0060] In step S230, ammonia is gradually added during the reaction until the pH value stabilizes at around 7. It should be understood that, since the composite emulsion is essentially a thermodynamically unstable colloidal dispersion system, its stability is highly dependent on the charge balance on the surface of the polymer particles. During thermal activation and functional group modification, the addition of the curing agent and the proceeding of the chemical reaction inevitably alter the ionic strength and acid-base environment of the system, easily causing an imbalance in the surface charge of the polymer particles, leading to irreversible aggregation or demulsification. Therefore, in the technical solution of this application, ammonia is further gradually added during the reaction until the pH value stabilizes at around 7, thereby dynamically neutralizing any acidic or alkaline substances that may be generated during the reaction, precisely anchoring the chemical environment of the entire reaction system in the neutral region. This effectively maintains the electrostatic repulsion between the polymer colloidal particles, ensuring the dispersion stability of the composite emulsion throughout the chemical modification process, preventing the formation of macroscopic polymer gel blocks due to local pH abrupt changes, and thus ensuring that the final activated polymer precursor has high homogeneity.

[0061] In a specific example of this application, the pH adjustment process is performed simultaneously with the thermal activation reaction. First, the operator places a calibrated online pH electrode probe below the liquid surface in the reaction vessel and connects it to a digital display instrument to continuously or periodically monitor the pH of the composite emulsion. Starting with the addition of the curing agent and defoamer, pH readings are recorded every 20 minutes. If the pH value deviates from the neutral range (e.g., below 6.5 or above 7.5), a suitable amount of ammonia solution is drawn using a precision pipette and slowly added dropwise to the composite emulsion through the feed port of the reaction vessel, while stirring is maintained to ensure rapid and uniform mixing. This monitoring-addition-mixing cycle is repeated until the pH value stabilizes at approximately 7 for two consecutive measurements. At this point, the addition of ammonia is stopped, completing the pH adjustment, and the reaction continues until the predetermined time is reached.

[0062] Specifically, in step S300, an improved aqueous solution is obtained by constructing an interfacial coupling system for the activated polymer precursor based on deionized water and a silane coupling agent. It should be understood that due to the inherent chemical incompatibility and significant interfacial energy difference between the organic phase of the activated polymer precursor and the inorganic phase of the cement matrix, direct blending would only result in weak van der Waals forces or physical adsorption at the interface, easily forming a weak interfacial transition zone with poor adhesion. This severely restricts the load transfer efficiency and long-term durability of the final organic-inorganic interpenetrating network. Therefore, in the technical solution of this application, an improved aqueous solution is further constructed by constructing an interfacial coupling system for the activated polymer precursor based on deionized water and a silane coupling agent. This utilizes the bifunctional characteristics of the silane coupling agent, allowing the organic functional group at one end to chemically bond with the polymer chain segment in the precursor, while the siloxane group at the other end hydrolyzes under the action of deionized water to generate highly active silanol groups. In this way, the silanol groups prepared to react with inorganic substances can be pre-grafted onto the polymer backbone, thereby pre-establishing a molecular bridge between the organic and inorganic phases. This bridge will form a stable chemical covalent bond with the hydroxyl groups on the surface of cement hydration products in the subsequent mixing stage, fundamentally improving the interfacial bonding strength between the organic and inorganic phases.

[0063] More specifically, in the embodiments of this application, an improved aqueous solution is obtained by constructing an interfacial coupling system for an activated polymer precursor based on deionized water and a silane coupling agent. This includes: adding deionized water to the activated polymer precursor to adjust the liquid phase concentration of the system; and after adding the silane coupling agent, maintaining stirring at 50°C to allow the silane coupling agent to fully hydrolyze in the system and bind with polymer segments to obtain the improved aqueous solution. More specifically, in a specific example of this application, firstly, the required volume of deionized water to be added is calculated according to the process formulation (subtracting the water content carried by the activated polymer precursor itself), and added to a reaction vessel containing the activated polymer precursor to adjust the liquid phase concentration of the system to a preset process window, ensuring that the concentration of subsequent reactants is appropriate and the system has good fluidity. Subsequently, a specified amount of silane coupling agent (e.g., 1% of the total mass of the polymer solids) is accurately weighed and added to the diluted precursor solution under continuous stirring. Finally, the system temperature of the reaction vessel is maintained at 50°C, and constant stirring is maintained. Under these conditions, the silane coupling agent undergoes complete hydrolysis in a hydrothermal environment. Its hydrolysis products (silanol groups) undergo grafting reactions with the active functional groups on the polymer chain segments until the reaction is complete. Finally, an improved aqueous solution with interfacial coupling groups successfully anchored on the molecular chain is obtained. This solution provides sufficient interfacial chemical preparation for subsequent mixing with ordinary silicate cement.

[0064] Specifically, in step S400, the modified aqueous solution and ordinary silicate cement are subjected to solid-liquid mixing, high-speed shearing, and homogenization dispersion to obtain a fresh composite modified slurry. It should be understood that because ordinary silicate cement particles have strong surface energy in the liquid phase and are prone to agglomeration, simple low-speed stirring alone cannot effectively wet and penetrate the interior of the cement particle clusters, resulting in a highly uneven distribution of the polymer and inorganic phases. Ultimately, after solidification, this leads to a heterogeneous structure containing numerous weak interfaces. Therefore, in the technical solution of this application, the modified aqueous solution and ordinary silicate cement are further subjected to solid-liquid mixing, high-speed shearing, and homogenization dispersion to obtain a fresh composite modified slurry. This utilizes the strong shear stress field generated by high-speed rotation to forcibly break the initial agglomeration structure of the cement particles and promote the micronization of polymer droplets carrying interfacial coupling groups, thereby uniformly coating the surface of individual cement particles. In this way, a highly homogeneous organic-inorganic composite system can be constructed at the microscale, providing an ideal material and spatial basis for the subsequent cement hydration and in-situ polymer curing to form a dense and continuous interpenetrating network structure, thereby ensuring the stability and superiority of the macroscopic properties of the final cured slurry.

[0065] More specifically, in the embodiments of this application, the modified aqueous solution and ordinary Portland cement are subjected to solid-liquid mixing, high-speed shearing, and homogenization dispersion to obtain a fresh composite modified slurry. This includes: mixing the modified aqueous solution and ordinary Portland cement; increasing the stirring speed to 500 rpm and continuously stirring for 3 minutes to utilize high-speed shearing force to uniformly adsorb droplets of the modified aqueous solution onto the particle surface of the ordinary Portland cement, while simultaneously promoting the dispersion of the ordinary Portland cement particles. More specifically, in a specific example of this application, firstly, the modified aqueous solution prepared in the upstream process is placed in a dedicated slurry mixing container, and the low-speed stirring mode of the stirring device is started. Subsequently, accurately weighed ordinary Portland cement powder is added in batches and evenly to the stirring modified aqueous solution to ensure initial wetting of the cement particles and to avoid dust raising and clumping. After all the cement powder has been added, the speed of the stirring device is immediately increased to the high-speed shearing setting, i.e., 500 rpm, and precise timing begins from this moment. At this high speed, the stirring blades apply strong shearing, impact, and dispersing forces to the solid-liquid mixture, forcibly breaking up the agglomerates between cement particles and atomizing the modified aqueous solution droplets, which are then uniformly adsorbed onto the surface of each fine cement particle. This high-speed shearing and homogenization dispersion process continues for 3 minutes before stirring is stopped. At this point, a macroscopically uniform, agglomerated slurry with microscopically close contact between the polymer and cement particles has formed in the container, yielding a fresh composite modified slurry for subsequent processes.

[0066] Specifically, in step S500, the fresh composite modified slurry is subjected to structural densification and curing to obtain a waterborne polyurethane-waterborne epoxy resin composite modified cement-based grouting material with high impermeability. It should be understood that during the initial high-speed shear mixing process, trace amounts of air inevitably become trapped within the fresh composite modified slurry. If these residual air bubbles are not removed, they will form microscopic pore defects after curing. Simultaneously, the formation of the organic-inorganic interpenetrating network structure is a complex process dependent on the synergistic reaction of cement hydration and polymer crosslinking, and its reaction kinetics are extremely sensitive to environmental conditions such as temperature and humidity. Therefore, in the technical solution of this application, the fresh composite modified slurry is further subjected to structural densification and curing to obtain a waterborne polyurethane-waterborne epoxy resin composite modified cement-based grouting material with high impermeability. This is done by forcibly expelling free and bound gases from the slurry through negative pressure to improve the physical density of the matrix and provide a stable and controlled curing environment for subsequent chemical reactions. This ensures that the continuous growth of cement hydration products and the in-situ crosslinking of polymer segments can proceed simultaneously and fully in a matrix free of macroscopic defects, ultimately resulting in an ideal organic-inorganic interpenetrating network structure with a complete microstructure and tight bonding between the two phases.

[0067] Figure 5 This is a flowchart illustrating the process of densifying and curing a fresh composite modified grout to obtain a waterborne polyurethane-waterborne epoxy resin composite modified cementitious grouting material with high impermeability according to embodiments of this application. Figure 5 As shown, step S500 includes: S510, degassing the fresh composite modified slurry under negative pressure to obtain the degassed slurry; S520, after the degassed slurry is injected into a preset mold, it is cured under constant temperature and humidity conditions, wherein the cement hydration products and polymer chains undergo a synergistic reaction to form an organic-inorganic interpenetrating network structure in situ.

[0068] More specifically, in one particular example of this application, the densification and curing process first involves negative pressure degassing. Operators transfer fresh composite modified slurry into a vacuum container such as a Buchner funnel and connect a vacuum pump system. The vacuum pump is activated, reducing the pressure inside the container to a preset negative pressure value and maintaining this pressure for 2 minutes. The pressure difference causes the tiny air bubbles trapped within the slurry to expand and escape to the slurry surface, resulting in a degassed slurry. Subsequently, the degassed slurry is immediately poured or injected evenly into a pre-prepared standard mold, and then vibrated or leveled to ensure a dense filling. After molding, the mold carrying the slurry is moved entirely into a constant temperature and humidity standard curing chamber, where the curing temperature is set to 20 degrees Celsius and the relative humidity to be above 95%, and cured for a specified period. During this period, the cement particles undergo full hydration, and the resulting hydration products undergo a synergistic cross-linking reaction with the polymer segments in the modified aqueous solution. They also form chemical bonds at the interface between the two phases through a silane coupling agent, and finally solidify in situ within the mold to obtain a modified cement paste product with a preset shape and a dense organic-inorganic interpenetrating network structure.

[0069] The following is a comparison of experimental data between the traditional static dripping control method and the preferred adaptive dripping control method based on rheological-thermodynamic coupling:

[0070] The experimental data for the first group using the traditional static dripping control method are shown in the table below:

[0071]

[0072] The experimental data for the second group, based on the adaptive dropping control method of rheological-thermodynamic coupling, are shown in the table below:

[0073]

[0074] The above experimental results show that:

[0075] 1. The residual bubble volume percentage of the activated precursor directly reflects the defoaming efficiency during the dropping process. Traditional static dropping methods cannot cope with the decrease in defoamer efficiency caused by the increase in viscosity in the later stages of the reaction, resulting in a large number of microbubbles remaining in the precursor (average 1.89%). However, the adaptive dropping control method used in the preferred embodiment, through real-time sensing and viscosity compensation, can maintain a high defoaming capacity even at high viscosity, significantly reducing the residual bubble volume percentage in the precursor to an average of 0.20%, laying the foundation for the formation of a dense microstructure.

[0076] 2. The porosity of the sample after 28 days of curing is a key indicator for measuring the density of the material. In the preferred embodiment, the adaptive drop-addition control effectively eliminates the initial defect source of microbubbles during the precursor preparation stage, resulting in a more dense and complete organic-inorganic interpenetrating network structure after curing. Its porosity (average 12.2%) is significantly lower than that of the comparative example (average 18.5%). This confirms the decisive role of adaptive drop-addition control in optimizing the final material microstructure.

[0077] 3. The compressive strength of the sample after 28 days of curing is directly related to the macroscopic mechanical properties of the material and the integrity of its microstructure. Pores, as stress concentration points, severely weaken the load-bearing capacity of the material. In the preferred embodiment, the adaptive drop-feed control method, due to its lower porosity, shows that its compressive strength (average 25.1 MPa) is increased by approximately 54.0% compared to the comparative example (average 16.3 MPa), indicating that the denser microstructure brings about a significant enhancement in mechanical properties.

[0078] 4. The impermeability coefficient of the sample after 28 days of curing is a core indicator for evaluating the effectiveness of the sealing material. Pores are the main channels for fluid permeation; the lower the porosity, the smaller the pore size, and the worse the connectivity, the better the impermeability. In the preferred embodiment, the sample using the adaptive dripping control method exhibits a significantly reduced impermeability coefficient, reaching 8.7 x 10⁻⁶, due to its highly dense microstructure. -12 The m / s level is far superior to the comparative example of 6.1 x 10 in the traditional static dropping method. -10 m / s. This fully demonstrates the significant advantages of the technical solution in this application in improving the waterproofing and sealing capabilities of materials.

[0079] The experimental data comparison table clearly shows that, compared with the traditional static dripping method, the adaptive dripping control mechanism based on rheological thermodynamic coupling proposed in this application significantly improves the microstructural integrity of the final cured product by eliminating microbubble defects from the source, thereby enhancing the compressive strength and impermeability of the modified cement paste.

[0080] In particular, Figure 6 This is a microstructure diagram of polymer-modified hardened cement paste. (Example:) Figure 6 As shown, where, Figure 6 (a) shows the microstructure of ordinary cement, which is characterized by loose and porous structure and well-developed cracks. Figure 6 (b) and (c) in the figure show the effect of single polymer (WPU or WEP) modification. Although there is some improvement, obvious pores and cracks are still visible, indicating that the effect of single modification is limited. Figure 6 Images (d), (e), and (f) show the microstructure of modified cement with different WPU-WEP ratios at 5000x magnification. Figure 6(d) and (e) in the figure show the microstructure of the composite modification of WPU:WEP = 3:1 and 2:1. There are almost no obvious cracks or pores between the hydration products, which shows a continuous, uniform and dense structure. Figure 6 Figure (f) shows the microstructure of the WPU:WEP composite modification at a ratio of 1:1. A small number of sparse pores can be observed, but the overall density is significantly better than that of single polymer (WPU or WEP) modification. This indicates that WPU-WEP jointly participate in pore filling and interface reconstruction during the hydration reaction, forming an interpenetrating network (IPN) spatial structure composed of organic phase and hydration products. This reduces the formation of interconnected pores and microcracks, and promotes the formation and uniform distribution of hydration products.

[0081] Figure 7 This is a diagram showing the pore structure and impermeability coefficient of polymer-modified materials. (Example:) Figure 7 As shown, where, Figure 7 Figure (a) shows the pore size distribution. The pore size of ordinary cement is mainly distributed in the coarser mesopore range. However, the pore size of the composite modified sample is significantly reduced, and most of the pores are concentrated in the micropore region below micrometers. This indicates that the IPN structure formed by this scheme effectively fills and refines the pores, transforming harmful macropores into harmless or less harmful micropores. Figure 7 (b) directly relates to the pore structure and the impermeability coefficient. The figure shows that the impermeability coefficient of the composite modified sample is reduced by two orders of magnitude compared to ordinary cement, reaching an extremely low level. This strongly demonstrates that the modified cement paste prepared in this scheme possesses superior impermeability, a property stemming from its dense microporous structure.

[0082] Figure 8 This diagram illustrates the chemical and physical modification mechanisms of WPU-WEP composite materials. Figure 8 As shown in the figure, this diagram explains at the molecular level how waterborne polyurethane (WPU) and waterborne epoxy resin (WEP) interact with cement hydration products (Ca). 2+ This explains the theoretical basis for the chemical cross-linking of WPU, forming an organic-inorganic interpenetrating network. In other words, it explains the hydrolysis of WPU, the ring-opening of WEP, and the interaction between the two via Ca... 2+ The process of ion bridging to form a co-crosslinked network. This explains why thermal activation and functional group modification of WPU and WEP are necessary (i.e., initiating ring-opening, hydrolysis, and other reactions), and why interfacial coupling systems need to be constructed (e.g., introducing silane coupling agents).

[0083] In summary, the preparation process of the waterborne polyurethane-waterborne epoxy resin composite modified cement-based grouting material with high impermeability according to the embodiments of this application has been clarified. Firstly, through systematic research, the optimal synergistic effect of waterborne polyurethane and waterborne epoxy resin at a mass ratio of 2:1 was determined, and the technical path to achieve ultrafine particle size and a balance between rigidity and flexibility by utilizing the advantages of this formulation was identified. To ensure that the theoretical performance of this optimized formulation is realized in actual preparation, this process constructs a full-process control scheme from precursor activation to interface system construction: in the thermal activation stage, an adaptive dripping mechanism is introduced to eliminate bubble defects in response to the viscosity coupling effect; in the precursor treatment stage, a silane coupling agent is used to graft pre-set molecular bridges to solve compatibility issues; finally, high-speed shearing and negative pressure degassing achieve highly dense curing and molding. This scheme integrates the material science optimization of component ratios with the process science precision control of the preparation process from the source, effectively solving the problems of poor permeability, weak interfacial bonding, and insufficient impermeability caused by imprecise formulations and rough processes in traditional schemes.

[0084] Furthermore, a waterborne polyurethane-waterborne epoxy resin composite modified cement-based grouting material with high impermeability is also provided, which is prepared by the above-mentioned preparation process of the waterborne polyurethane-waterborne epoxy resin composite modified cement-based grouting material with high impermeability.

[0085] The various embodiments of this disclosure have been described above. These descriptions are exemplary and not exhaustive, nor are they limited to the disclosed embodiments. Many modifications and variations will be apparent to those skilled in the art without departing from the scope and spirit of the described embodiments. The terminology used herein is chosen to best explain the principles, practical application, or improvement of the technology in the market, or to enable others skilled in the art to understand the embodiments disclosed herein.

Claims

1. A preparation process for a waterborne polyurethane-waterborne epoxy resin composite modified cement-based grouting material with high impermeability, characterized in that, include: Waterborne polyurethane and waterborne epoxy resin are premixed and homogenized to obtain a composite emulsion. Based on curing agents, defoamers, and ammonia, composite emulsions are thermally activated and functionalized to obtain activated polymer precursors, including: After transferring the composite emulsion to the reaction vessel, turn on the water bath for heating; The curing agent and defoamer are added dropwise to the reaction vessel using a dropper to ensure uniform dispersion of the curing agent to initiate the ring-opening reaction of the epoxy functional groups in the waterborne epoxy resin. Simultaneously, the defoamer suppresses bubble formation during the process. This includes: acquiring real-time stirring torque, real-time system temperature, and emulsion level; and performing multi-dimensional sensing of the reaction rheological state and foam characteristics based on the real-time stirring torque, real-time system temperature, and emulsion level to obtain reaction kinetic indices and a foam retention index. The calculation formula for the reaction kinetic indices is as follows: in, The reaction kinetic index at time t. For real-time stirring torque; For real-time system temperature, and It is an adjustable weighting factor; The formula for calculating the foam retention index is as follows: in, Let be the bubble retention index at time t. Let be the emulsion level height at time t. The theoretical liquid level height at time t based on the feed rate; The reaction kinetics and foam retention index were calculated using a viscosity-coupled compensation-based dropping strategy to obtain the target flow rates of the curing agent and defoamer. The formula for calculating the target flow rate of the curing agent is as follows: in, Let be the target flow rate of the curing agent at time t. Based on the flow rate, It is an inhibitory factor; The preset dynamic index threshold; The formula for calculating the target flow rate of the defoamer is as follows: in, Let t be the target flow rate of the defoamer. Basic response coefficient, This is the viscosity compensation coefficient. For real-time stirring torque; The actuator performs pulse width modulation (PWM) control on the target flow rates of the curing agent and defoamer to obtain the curing agent pump control signal and the defoamer pump control signal, respectively. The curing agent pump control signal and the defoamer pump control signal are PWM duty cycle signals obtained by calculating the target flow rates of the curing agent and defoamer, respectively. The calculation formula for the PWM duty cycle signal is as follows: in, Let t be the pump's output duty cycle. Let be the target flow velocity at time t, corresponding to or , This refers to the pump's displacement per revolution. This refers to the pump's maximum speed. Ammonia was gradually added during the reaction until the pH value stabilized at 7; An improved aqueous solution was obtained by constructing an interfacial coupling system for activated polymer precursors based on deionized water and silane coupling agents. A fresh composite modified slurry was obtained by solid-liquid mixing, high-speed shearing, and homogenization dispersion of an improved aqueous solution and ordinary silicate cement. Fresh composite modified grout is densified and cured to obtain a waterborne polyurethane-waterborne epoxy resin composite modified cement-based grouting material with high impermeability.

2. The preparation process of the waterborne polyurethane-waterborne epoxy resin composite modified cement-based grouting material with high impermeability according to claim 1, characterized in that, Premixing and homogenizing waterborne polyurethane and waterborne epoxy resin to obtain a composite emulsion includes: Waterborne polyurethane and waterborne epoxy resin are injected into a mixing container according to a preset mass ratio; Place the mixing container at ambient temperature and start the stirring device to stir continuously for 5 minutes to obtain a composite emulsion.

3. The preparation process of the waterborne polyurethane-waterborne epoxy resin composite modified cement-based grouting material with high impermeability according to claim 1, characterized in that, An improved aqueous solution was obtained by constructing an interfacial coupling system for activated polymer precursors based on deionized water and silane coupling agents, including: Deionized water was added to the activated polymer precursor to adjust the liquid phase concentration of the system; After adding the silane coupling agent, stirring is maintained at 50°C to allow the silane coupling agent to be fully hydrolyzed in the system and combined with polymer segments to obtain an improved aqueous solution.

4. The preparation process of the waterborne polyurethane-waterborne epoxy resin composite modified cement-based grouting material with high impermeability according to claim 1, characterized in that, The process involves solid-liquid mixing, high-speed shearing, and homogenization dispersion of an improved aqueous solution and ordinary silicate cement to obtain a fresh composite modified paste, including: The improved aqueous solution and ordinary silicate cement were mixed; Increase the stirring speed to 500 rpm and continue stirring for 3 minutes to utilize high-speed shear force to uniformly adsorb the droplets of the improved aqueous solution onto the particle surface of ordinary silicate cement, while promoting the dispersion of ordinary silicate cement particles.

5. The preparation process of the waterborne polyurethane-waterborne epoxy resin composite modified cement-based grouting material with high impermeability according to claim 1, characterized in that, A waterborne polyurethane-waterborne epoxy resin composite modified cementitious grouting material with high impermeability is obtained by structural densification and curing of fresh composite modified grout, including: Fresh composite modified slurry was degassed under negative pressure to obtain degassed slurry; After the degassed slurry is injected into a pre-set mold, it is cured under constant temperature and humidity conditions. During this process, cement hydration products and polymer chains undergo a synergistic reaction to form an organic-inorganic interpenetrating network structure in situ.

6. A waterborne polyurethane-waterborne epoxy resin composite modified cement-based grouting material with high impermeability, characterized in that, The waterborne polyurethane-waterborne epoxy resin composite modified cement-based grouting material with high impermeability is prepared by the preparation process of the waterborne polyurethane-waterborne epoxy resin composite modified cement-based grouting material with high impermeability as described in any one of claims 1-5.

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