Preparation process of non-combustible anti-leakage building material

Abstract

The application relates to the field of building material processing and discloses a preparation process of a non-combustible anti-leakage building material, which comprises the following steps: proportioning a polyurethane composition with an excess of isocyanate groups to make free sites remain on the surface of a foaming matrix; coating inorganic slurry containing an amino silane coupling agent on the surface of the matrix during the foaming reaction of the matrix to release heat and make the surface be at 45 DEG C to 55 DEG C; driving the addition reaction of the amino group at the end of the coupling agent and the free sites to generate an in-situ covalent urea bond anchoring structure at the interface between the organic and inorganic phases by using the reaction residual heat; and constructing a chemical bonding interface by the dehydration and polycondensation of the silanol end of the coupling agent and the inorganic network, the application uses cross-phase state chemical bonding to replace physical adsorption, eliminates the peeling risk caused by the difference in thermal expansion coefficients at the interface between two phases, and maintains the structural integrity of the composite material under the thermal shock working condition.

Description

Technical Field

[0001] This invention belongs to the field of building material processing technology, and in particular relates to a preparation process for a non-combustible and leak-proof building material. Background Technology

[0002] Polyurethane materials, with their closed-cell structure and low thermal conductivity, are widely used in leak-proofing and insulation of building components. Coating polyurethane surfaces with inorganic silicate slurry is a common technique to improve the fire resistance of organic-inorganic composite systems. However, the coefficients of thermal expansion of the organic polyurethane matrix and the inorganic silicate coating differ by orders of magnitude. Conventional processes require coating after the polyurethane matrix has fully matured and released its foaming stress. At this point, the chemically active groups on the matrix surface have largely completed cross-linking, resulting in the bonding between the coating and the matrix relying mainly on mechanical interlocking and van der Waals forces. Under the thermal shock conditions of the initial stage of a fire, thermal stress accumulates at the interface between the two phases, causing brittle cracking and large-area peeling of the inorganic layer, leading to the failure of the fire barrier and exposing the internal flammable matrix. Increasing the coating thickness or roughening the surface increases the weight of the composite system and cannot eliminate the interfacial stress concentration caused by the difference in physical properties.

[0003] Besides structural limitations, the control methods also have shortcomings. For example, Chinese invention patent application CN120988569A discloses an inorganic silicon hybrid polyurethane primer, its preparation method, and its application. It uses silane hydrolysis to form a Si-O-Si network that bonds with concrete and utilizes isocyanate groups to react with water to generate urea bonds for enhanced anchoring. This type of solution is designed for hardened concrete substrates. The chemical bond formation kinetics depend on environmental moisture, and the reaction rate is slow. It cannot match the thermodynamic characteristics of the polyurethane foaming process. When faced with a 600°C thermal shock, it lacks the ability to capture residual heat from foaming and utilize the interfacial activity window. This makes it difficult for the covalent bond anchoring density at the organic-inorganic interface to reach the threshold required to resist thermal stress. Under the action of thermo-mechanical coupling, toughness loss and interfacial failure occur.

[0004] Therefore, how to determine the interfacial activity window during the polyurethane foaming process and drive the residual isocyanate groups on the matrix surface to chemically crosslink with the slurry components in order to improve the interfacial stability of the composite material under thermal shock conditions has become the technical problem to be solved by this invention. Summary of the Invention

[0005] This invention proposes a preparation process for a non-combustible, leak-proof building material, which includes the following steps: Step S1: Prepare a polyurethane composition. The polyurethane composition includes polyphenyl polymethylene polyisocyanate, combined polyether, and a composite flame retardant system composed of ammonium polyphosphate, melamine, and expanded graphite. The excess isocyanate groups in the polyphenyl polymethylene polyisocyanate are controlled so that free isocyanate groups remain on the surface of the polyurethane foam matrix during the foaming stage. Step S2: Initiate the foaming reaction of the polyurethane composition and use the heat of reaction released by the foaming reaction to keep the surface temperature of the polyurethane foam matrix at 45°C to 55°C. Step S3, while the surface temperature of the polyurethane foam matrix is ​​between 45°C and 55°C, the product containing... An inorganic slurry of -aminopropyltriethoxysilane coupling agent is coated on the surface of a polyurethane foam matrix. The inorganic slurry includes a sodium silicate solution with a modulus of 2.8 to 3.2, aluminum hydroxide powder, and talc powder. Step S4, driven by the heat of reaction - The terminal amino group of the aminopropyltriethoxysilane coupling agent undergoes an addition reaction with the free isocyanate group, forming a covalent urea bond anchoring structure in situ at the interface between the organic and inorganic phases. Step S5, through - The silanol end of the aminopropyltriethoxysilane coupling agent undergoes dehydration and polycondensation with the sodium silicate network in the inorganic slurry, forming a chemically bonded interface between the polyurethane foam matrix and the inorganic coating.

[0006] Preferably, step S2 further includes: step S21: by controlling the molding thickness of the polyurethane foam matrix and the starting temperature of the foaming reaction, the effective reaction heat time domain formed on the surface of the polyurethane foam matrix is ​​made to last for 120s to 300s, and the temperature fluctuation range within the effective reaction heat time domain is within ±2℃, so that the addition reaction in step S4 crosses the reaction activation energy threshold, and a chemical bond density of not less than 1000 bonds / μm is formed at the interface. 2 The covalent urea bond anchoring structure.

[0007] Preferably, step S1 further includes: step S11: controlling the molar ratio of isocyanate groups to hydroxyl groups in the combined polyether to be 1.05:1 to 1.20:1, and through the over-design of the stoichiometric ratio, the surface of the polyurethane foam matrix is ​​distributed with active sites for reacting with the terminal amino groups in the early stage of crosslinking.

[0008] Preferably, based on 100 parts by weight of the total polyurethane composition, the content of ammonium polyphosphate is 10 to 15 parts, the content of melamine is 5 to 8 parts, and the content of expanded graphite is 3 to 6 parts.

[0009] Preferably, in step S3, the mass ratio of each component in the inorganic slurry is: 40 to 60 parts sodium silicate solution, 15 to 25 parts aluminum hydroxide powder, and 10 to 20 parts talc.

[0010] Preferably, in step S3, a high-pressure airless spraying process is used for coating, the spraying pressure is set to 15MPa to 20MPa, and the cured thickness of the inorganic coating after spraying is controlled to be 1.5mm to 3.0mm.

[0011] Preferably, step S3 further includes: step S31: ultrasonically dispersing the inorganic slurry, setting the ultrasonic frequency to 20kHz to 40kHz, and the duration to 10min to 20min, to eliminate microbubbles in the inorganic slurry and improve... - The uniformity of concentration of aminopropyltriethoxysilane coupling agent in the slurry system.

[0012] Preferably, the preparation process further includes: step S6: the material after step S5 is introduced into a curing environment, the temperature is set to 25°C to 35°C, the relative humidity is 60% to 70%, and the aging time is not less than 24 hours, so that the chemical bonding interface can be structurally strengthened.

[0013] Preferably, the covalent urea bond anchoring structure formed in step S4 ensures that the interfacial bond strength between the inorganic coating and the polyurethane foam matrix remains at more than 80% of the initial strength under a thermal shock environment of 600°C.

[0014] Compared with existing technologies, the preparation process of the non-combustible and leak-proof building material of this invention has the following advantages: 1. In the preparation of non-combustible and leak-proof building materials, by excessively configuring polyphenyl polymethylene polyisocyanate in the formula, free isocyanate groups are retained on the surface of the polyurethane foam matrix during the foaming stage. The residual heat generated during the foaming process drives the isocyanate groups to undergo an addition reaction with the coupling agent in the inorganic coating, thereby constructing a covalent urea bond anchoring structure in situ at the interface between the organic and inorganic phases. This chemical bonding mechanism replaces physical adsorption, eliminates the risk of interfacial delamination between the organic matrix and the inorganic coating due to the difference in thermal expansion coefficients, and maintains the structural integrity of the composite material under thermal shock conditions.

[0015] 2. A composite flame-retardant system constructed from ammonium polyphosphate, melamine, and expanded graphite forms a phosphorus-nitrogen synergistic gas-phase shielding and condensed-phase char formation mechanism within the polyurethane matrix. Combined with the physical barrier of heat flow provided by the surface inorganic coating, a gradient protection system is formed from the outside in. Due to the chemical bond connection at the interface, the inorganic coating maintains its density under high-temperature conditions, effectively blocking the decomposition path of the internal organic components, thus giving the overall material a stable A2-level non-combustible characteristic.

[0016] 3. The temperature of 45℃ to 55℃ during the cooling stage of polyurethane foaming is selected as the trigger window for the coating action. This matches the reactivity of the isocyanate groups with the penetration rate of the inorganic slurry. This process sequence ensures that the coupling agent hydrolysate and the active sites on the substrate surface collide and crosslink effectively. Interface modification can be completed by the system's own heat generation without external forced heating, which improves production efficiency while ensuring the consistency of product quality. Attached Figure Description

[0017] Figure 1 This is a flowchart of the organic-inorganic phase interface covalent anchoring preparation process of the present invention; Figure 2 This is a logic block diagram of dynamic temperature compensation for the interface active window in this invention. Detailed Implementation

[0018] The technical solutions of the embodiments of this application will be clearly described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of this application are within the scope of protection of this application.

[0019] It should be noted that all directional and positional terms used in this invention, such as: up, down, left, right, front, back, vertical, horizontal, inner, outer, top, bottom, transverse, longitudinal, center, etc., are only used to explain the relative positional relationship and connection between components in a specific state (as shown in the accompanying drawings). They are only for the convenience of describing this invention and do not require that this invention be constructed and operated in a specific orientation. Therefore, they should not be construed as limiting this invention. In addition, the descriptions of "first," "second," etc., in this invention are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated.

[0020] In the description of this invention, unless otherwise explicitly specified and limited, the terms installation, connection, and linking should be interpreted broadly. For example, they can refer to fixed connections, detachable connections, or integral connections; they can refer to mechanical connections; they can refer to direct connections or indirect connections through an intermediate medium; they can refer to the internal connection of two components. For those skilled in the art, the specific meaning of the above terms in this invention can be understood in conjunction with the specific circumstances.

[0021] In the description of this specification, references to the terms "an embodiment," "some embodiments," "illustrative embodiments," "examples," "specific examples," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example, and the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0022] A preparation process for a non-combustible, leak-proof building material, comprising the following steps: Step S1: Prepare a polyurethane composition. The polyurethane composition includes polyphenyl polymethylene polyisocyanate, combined polyether, and a composite flame retardant system composed of ammonium polyphosphate, melamine, and expanded graphite. The excess isocyanate groups in the polyphenyl polymethylene polyisocyanate are controlled so that free isocyanate groups remain on the surface of the polyurethane foam matrix during the foaming stage. Step S2: Initiate the foaming reaction of the polyurethane composition and use the heat of reaction released by the foaming reaction to keep the surface temperature of the polyurethane foam matrix at 45°C to 55°C. Step S3, while the surface temperature of the polyurethane foam matrix is ​​between 45°C and 55°C, the product containing... An inorganic slurry of -aminopropyltriethoxysilane coupling agent is coated on the surface of a polyurethane foam matrix. The inorganic slurry includes a sodium silicate solution with a modulus of 2.8 to 3.2, aluminum hydroxide powder, and talc powder. Step S4, driven by the heat of reaction - The terminal amino group of the aminopropyltriethoxysilane coupling agent undergoes an addition reaction with the free isocyanate group, forming a covalent urea bond anchoring structure in situ at the interface between the organic and inorganic phases. Step S5, through - The silanol end of the aminopropyltriethoxysilane coupling agent undergoes dehydration and polycondensation with the sodium silicate network in the inorganic slurry, forming a chemically bonded interface between the polyurethane foam matrix and the inorganic coating.

[0023] Preferably, step S2 further includes: step S21: by controlling the molding thickness of the polyurethane foam matrix and the starting temperature of the foaming reaction, the effective reaction heat time domain formed on the surface of the polyurethane foam matrix is ​​made to last for 120s to 300s, and the temperature fluctuation range within the effective reaction heat time domain is within ±2℃, so that the addition reaction in step S4 crosses the reaction activation energy threshold, and a chemical bond density of not less than 1000 bonds / μm is formed at the interface. 2 The covalent urea bond anchoring structure.

[0024] Preferably, step S1 further includes: step S11: controlling the molar ratio of isocyanate groups to hydroxyl groups in the combined polyether to be 1.05:1 to 1.20:1, and through the over-design of the stoichiometric ratio, the surface of the polyurethane foam matrix is ​​distributed with active sites for reacting with the terminal amino groups in the early stage of crosslinking.

[0025] Preferably, based on 100 parts by weight of the total polyurethane composition, the content of ammonium polyphosphate is 10 to 15 parts, the content of melamine is 5 to 8 parts, and the content of expanded graphite is 3 to 6 parts.

[0026] Preferably, in step S3, the mass ratio of each component in the inorganic slurry is: 40 to 60 parts sodium silicate solution, 15 to 25 parts aluminum hydroxide powder, and 10 to 20 parts talc.

[0027] Preferably, in step S3, a high-pressure airless spraying process is used for coating, the spraying pressure is set to 15MPa to 20MPa, and the cured thickness of the inorganic coating after spraying is controlled to be 1.5mm to 3.0mm.

[0028] Preferably, step S3 further includes: step S31: ultrasonically dispersing the inorganic slurry, setting the ultrasonic frequency to 20kHz to 40kHz, and the duration to 10min to 20min, to eliminate microbubbles in the inorganic slurry and improve... - The uniformity of concentration of aminopropyltriethoxysilane coupling agent in the slurry system.

[0029] Preferably, the preparation process further includes: step S6: the material after step S5 is introduced into a curing environment, the temperature is set to 25°C to 35°C, the relative humidity is 60% to 70%, and the aging time is not less than 24 hours, so that the chemical bonding interface can be structurally strengthened.

[0030] Preferably, the covalent urea bond anchoring structure formed in step S4 ensures that the interfacial bond strength between the inorganic coating and the polyurethane foam matrix remains at more than 80% of the initial strength under a thermal shock environment of 600°C.

[0031] Example 1: In the sealing of building components facing the initial thermal shock of 600℃ in the early stages of a fire and requiring long-term waterproofing and leak-proofing, the traditional organic polyurethane materials and inorganic silicate coatings, due to the difference in their coefficients of thermal expansion, experience significant thermal stress accumulation at the interface relying on physical and mechanical interlocking during rapid temperature rise, leading to cracking and peeling of the inorganic layer. To address the peeling risk caused by phase differences, a polyurethane composition was selected, consisting of polyphenyl polymethylene polyisocyanate, combined polyether, and a composite flame-retardant system composed of ammonium polyphosphate, melamine, and expanded graphite. The isocyanate groups in the polyphenyl polymethylene polyisocyanate and the combined polyether were controlled. The molar ratio of hydroxyl groups in the polyether is 1.05:1 to 1.20:1. An excess of stoichiometric groups allows free isocyanate group active sites to remain on the surface of the polyurethane foam matrix during the initial stage of foaming and crosslinking. This initiates the foaming reaction of the polyurethane composition, utilizing the heat released to maintain the surface temperature of the polyurethane foam matrix between 45°C and 55°C. While the foaming volume expansion stops and the matrix surface temperature remains between 45°C and 55°C, a solution containing γ-aminopropyltriethoxysilane coupling agent, sodium silicate solution with a modulus of 2.8 to 3.2, aluminum hydroxide powder, and talc is added. The slurry is applied to the surface of the polyurethane foam matrix using a spraying pressure of 15MPa to 20MPa. By controlling the molding thickness of the polyurethane foam matrix and the onset temperature of the foaming reaction, the effective reaction heat generation time domain duration on the matrix surface is ensured to reach 120s to 300s with temperature fluctuations within ±2℃. In specific operations, a one-dimensional unsteady-state thermal conduction coupling mathematical model of the foaming reaction kinetics and different matrix thicknesses is pre-established. Using an onset temperature of 25℃ under controlled conditions as a benchmark, the time-series curve of the unit volume heat release power of polyurethane under a specific formulation is extracted. For 20mm to... Different molding thicknesses within an 80mm range are calculated in reverse according to the heat transfer model to match specific initial temperature environmental biases. This ensures that the combined effect of increased internal total heat capacity and extended heat dissipation path caused by increased thickness is completely offset by a precisely tuned cooling curve within the reaction time domain. This ensures that the peak transient heat flux transferred from the deep layers to the outer layers of the system is output smoothly, and that the heat reaching the surface to participate in the reaction falls within the target steady-state window of 45℃ to 55℃. This reaction heat is used to drive the addition reaction between the terminal amino groups of the γ-aminopropyltriethoxysilane coupling agent in the inorganic slurry and the free isocyanate groups on the matrix surface.

[0032] A covalent urea bond anchoring structure was generated in situ at the interface, and a cross-phase chemical bonding interface was constructed by dehydration and polycondensation of the silanol end of the γ-aminopropyltriethoxysilane coupling agent with the sodium silicate network in the inorganic slurry. Based on the positive correlation between the vibrational frequency of specific chemical bonds and the area of ​​infrared absorption peaks, the covalent bond density at the interface was quantitatively characterized by attenuated total reflectance Fourier transform infrared spectroscopy. The coated and cured sample was cut along the chemical bonding interface, and the polyurethane foam matrix side contact surface was peeled off and cut out as the test surface. Ten square observation windows with a side length of one micrometer were selected on the test surface using a germanium crystal spectrometer. To meet the effective optical path refraction and physical contact surface requirements of total reflectance Fourier transform infrared spectroscopy at the micrometer-level extreme spatial resolution, the peeled polyurethane foam matrix side contact surface was placed in epoxy embedding resin for room temperature vacuum infiltration curing before entering the spectral observation window selection step. An ultrathin slicer equipped with diamond tools was used to perform extremely flat cutting and peeling on the test surface under a cryogenic liquid nitrogen environment to eliminate the macroscopic roughness differences of the porous network structure. Simultaneously, a synchrotron high-brightness infrared broadband light source and a high-sensitivity focal plane array detector were used. The mechanical aperture in the microscopy system was used to confine the lateral spot of the infrared detection beam within a square measurement micro-region with a side length of one micrometer from the physical optical diffraction level. This ensured that the high refractive index germanium crystal of the ATR accessory could achieve absolutely tight, air-gap-free pressure contact with the cryogenically cut extremely flat test surface. The baseline of the acquired spectral data was calibrated, and the integral area of ​​the urea bond absorption peak within a specific wavenumber characteristic range was extracted. Based on the conversion coefficient between the spectral area and the number of molecules obtained by calibration using a standard of known concentration, the absolute number of covalent urea bonds in each observation window was calculated. The arithmetic mean of the absolute number of molecules in ten observation windows was calculated to determine the chemical bond density. The aforementioned materials with chemically bonded interfaces are aged in a curing environment at a temperature of 25°C to 35°C and a relative humidity of 60% to 70% for at least 24 hours to achieve structural strengthening. This process integrates the phosphorus and nitrogen gas phase shielding and condensed phase charring mechanism constructed by the composite flame-retardant system within the polyurethane with the barrier effect of the surface inorganic coating, utilizing a chemical bond density of not less than 1000 bonds / μm. 2 The covalent urea bond anchoring structure replaces physical adsorption, overcoming the mismatch defect of thermal expansion coefficients between polyurethane and silicate. This allows the resulting material to maintain more than 80% of the initial strength of the interfacial bond strength between the inorganic coating and the polyurethane foam matrix under thermal shock at 600℃, thus maintaining the structural integrity and A2-level non-combustible properties of the composite material system under extreme conditions.

[0033] Example 2: In verifying the interfacial stability of polyurethane and inorganic composite fireproof materials in building components, conventional interfacial adhesion tests are insufficient to reproduce the environment accompanying structural deformation during the initial stage of a fire. To assess the reliability of the chemically bonded interface under thermo-coupling conditions, a dynamic thermal shock testing platform was constructed, including a high-temperature muffle furnace and a high-frequency electromagnetic vibration table. When setting the test environment parameters, the temperature change rate was constrained by the thermal stress accumulation rate and the relaxation response capability of polymer chain segments. When the thickness of the polyurethane foam matrix exceeded the baseline threshold, to avoid structural warping masking interfacial delamination, the temperature change rate needed to approach the upper limit of the test equipment's range. The thermal shock heating rate was set to 50℃ / min, and the maximum shock temperature was set to 600℃. During the heating process, a mechanical vibration with a frequency of 50Hz and an amplitude of 2mm was introduced as an environmental disturbance term to simulate the resonance noise of building pipelines caused by a fire. Multiple sets of samples were set up for lateral comparison, including an experimental group and three control groups. The molar ratio of isocyanate groups in the polyphenyl polymethylene polyisocyanate to hydroxyl groups in the combined polyether in the experimental group was 1.15:1. The coating slurry contained γ-aminopropyltriethoxysilane coupling agent, and the surface bonding temperature was controlled at 50℃. The molar ratio of control group one was set to 1.02:1, and the molar ratio of control group two was set to 1.25:1. The remaining components and parameters of control group one and control group two were consistent with those of the experimental group. The molar ratio of control group three was set to 1.15:1, and the γ-aminopropyltriethoxysilane coupling agent in the inorganic slurry was removed. The cured and aged samples were placed in a dynamic thermal shock test platform and subjected to coupled impact of 600℃ and mechanical vibration for 30 minutes. The interfacial bond strength retention rate of the samples was tested. This retention rate is the ratio of the bond strength after thermal shock to the initial bond strength at room temperature.

[0034] The interfacial bond strength was calculated by extracting the peak strength load from the electrical signal output by the tensile sensor via digital-to-analog conversion. The interfacial bond strength retention rate of control group three was 15.6%, exhibiting large-area brittle peeling under thermo-coupling impact; physical and mechanical interlocking could not resist the shear stress generated by phase differences. The interfacial bond strength retention rate of the experimental group reached 85.2%, maintaining a dense interface and filtering out the tearing disturbance of the interface caused by high-frequency mechanical vibration. The strength retention rate of control group one was 42.5%, with insufficient isocyanate group concentration leading to a low density of covalent urea bonds, failing to construct a continuous chemical anchoring network. The strength retention rate of control group two was 61.4%, with excessive isocyanate monomers... At the interface, a side reaction occurs with environmental moisture, releasing carbon dioxide gas and forming defect cavities, which leads to the deterioration of interfacial cohesion. Data gradients and nonlinear inflection points confirm that the molar ratio range of 1.05:1 to 1.20:1 is the parameter range for obtaining interfacial adhesion. In this molar ratio range, the free isocyanate groups and the γ-aminopropyltriethoxysilane coupling agent work synergistically to build a chemical anchoring bridge between the organic polyurethane macromolecules and the inorganic silicate network. The chemical bonding offsets the interfacial thermal stress accumulated due to the difference in thermal expansion coefficients between phases. The material maintains the structural integrity of the coating and the foam matrix under 600℃ and mechanical vibration coupling conditions, and outputs the composite material system with leak-proof and A2-grade non-combustible properties.

[0035] Example 3: In the continuous preparation of seepage prevention and sealing materials for building pipe wells, fluctuations in the ambient reference temperature cause a drift in the exothermic rate of the polyurethane composition foaming reaction. This drift causes the surface temperature of the polyurethane foam matrix to deviate from the preset range for the duration between 45°C and 55°C. The matrix that has not been fully foamed and cross-linked will collapse under spraying pressure. An infrared temperature sensor with a measurement accuracy of 0.1°C and a sampling frequency of 10Hz is used to continuously collect the real-time surface temperature of the polyurethane foam matrix. The processor fits the slope of temperature change based on a sliding time window of 50 sampling cycles. If the absolute value of the slope of temperature change is less than 0.5°C / s and the real-time surface temperature reaches 45°C, the processor determines that the foaming volume expansion has stopped and the free isocyanate groups on the surface meet the conditions for addition reaction.

[0036] The processor outputs a start command to the spraying equipment. The spraying equipment uses an initial spraying pressure of 15 MPa to coat the surface of the polyurethane foam matrix with an inorganic slurry containing γ-aminopropyltriethoxysilane coupling agent. During the inorganic slurry coating and interfacial reaction, the controller acquires surface temperature data in real time and calculates the temperature according to the formula. Calculate the output power of the infrared radiation heating lamp, where, For output power, The base sustaining power is set to 200W; The proportional control coefficient is set to 50W / ℃; The difference between the target center temperature of 50℃ and the real-time surface temperature is used. Based on the unidirectional work property of the electrothermal conversion element, when the foaming reaction is intense and the real-time surface temperature exceeds the target center temperature, the controller executes hardware constraints and calculates the output power. Constrained to be greater than or equal to zero watts, the output power is calculated according to the formula. When the power is less than or equal to zero, the controller outputs a zero-power command to cut off the power supply circuit of the infrared radiation heating lamp and stop active thermal radiation compensation. It then relies on the natural heat convection from the substrate surface to the surrounding environment to dissipate heat until the real-time surface temperature drops below the target center temperature, at which point the output power is recalculated. Greater than zero.

[0037] The controller compensates for the heat loss from the interface to the environment by adjusting the output power. During the operation cycle of this high-frequency intervention mechanism, the photothermal energy projected by the infrared radiation source, due to the physical blockage of the inorganic components, can only stagnate in the extremely shallow subsurface network of the inorganic slurry coating and eventually dissipates in the opposite direction to the external cold air following the temperature gradient. Its heat penetration depth is macroscopically much lower than the curing thickness of the coating itself, and will never reach the bottom polyurethane-inorganic interface. The bond breaking and recombination activation energy barrier required for the aminosilane coupling agent at the interface micro-phase to perform the nucleophilic addition reaction depends on the internal residual heat of the chemical foaming reaction that continuously surges upward from the depths of the polyurethane matrix due to the adiabatic gradient. Energy supply ensures that the underlying dynamic driving mechanism for interface bonding under actual working conditions of the building manhole is physically consistent with the fully driven mechanism of passive heating disclosed in a controlled constant temperature environment, achieving a closed-loop causal logic for the entire technical concept. The controller controls the effective reaction heat duration of the interface within the range of 120s to 300s, and maintains the temperature fluctuation range of the interface within ±2℃. The above closed-loop regulation process maintains the activation energy supply for the addition reaction of free isocyanate groups and amino groups. The constant temperature boundary conditions suppress the interference of environmental disturbances on the density of covalent urea bond formation. The composite material system outputs uniform interfacial bonding strength under continuous coating conditions.

[0038] Example 4: In the continuous preparation of sealing materials facing a large range of ambient temperature, the ambient temperature deviation causes the proportional control coefficient of the infrared radiation heating lamp to deviate from the preset compensation point. A pre-calibration procedure is established on-site. Before coating the inorganic slurry, standard test samples of the current batch of polyurethane composition are extracted. These test samples are placed in the construction site environment, and an infrared temperature sensor is used to monitor the time span from 55°C to 45°C on the surface of the test sample. The processor calculates the natural cooling rate based on the time span and uses the formula... Update the proportional control coefficient of the controller, where, This is the updated proportional control coefficient. The calibration constant is set to 150 W·s / , As a natural cooling rate, the pre-calibration procedure converts the environmental heat dissipation boundary differences into a quantitative compensation coefficient, so that the output power of the infrared radiation heating lamp matches the current environmental heat dissipation load.

[0039] After updating the proportional control coefficient, the continuous coating process is started. The spraying equipment issues power commands to the infrared radiation heating lamps according to the updated proportional control coefficients. The infrared radiation heating lamps output radiant heat that matches the ambient heat dissipation rate, maintaining the effective reaction heat domain duration at the interface within the range of 120s to 300s. The free isocyanate groups undergo an addition reaction with the terminal amino groups of the γ-aminopropyltriethoxysilane coupling agent and acquire a constant activation energy, generating a density of not less than 1000 groups / μm in situ at the interface. 2 The covalent urea bond anchoring structure of the composite material system maintains the interfacial bonding strength between the inorganic coating and the polyurethane foam matrix under different ambient temperature conditions.

[0040] Example 5: In continuous coating of polyurethane foam substrates of varying thicknesses, a fixed infrared radiation heating lamp power causes deviations in the substrate curing process and interfacial chemical bonding rate. Before continuous coating, multiple sets of polyurethane foam substrate standard parts covering the thickness of building manholes were prepared. Working conditions were simulated for substrate thicknesses of 20mm, 40mm, 60mm, and 80mm, and inorganic slurry coating was initiated after each standard part underwent foaming and crosslinking. An infrared temperature sensor was used to monitor and record the actual output power timing sequence of the infrared radiation heating lamp required to maintain the surface temperature of each standard part between 45℃ and 55℃ and achieve an 80% interfacial bond strength retention rate. The thickness characteristic and corresponding power timing sequence were input into the controller's feature database for offline calibration. The processor used a linear interpolation algorithm to fit an adjustment baseline for the base maintenance power at different thicknesses. Based on the principle that the total heat capacity of the system increases with the increase in medium volume, increasing the thickness of the foam substrate increases the total internal accumulated polymerization heat and slows down the spontaneous cooling rate of the interface. The adjusted baseline establishes a negative linear algebraic relationship between the foam substrate thickness and the base maintenance power, with the target maintenance power... The calculation formula is set as follows Target maintenance power Replace the default base sustaining power, with the unit watts being a positive real number; variable The thickness parameter of the polyurethane foam matrix is ​​in millimeters and is a real number greater than or equal to 20 and less than or equal to 80.

[0041] The controller iterates through the calibration steps to generate a baseline library of foundation maintenance power that adjusts according to the thickness of the polyurethane foam matrix. During the construction component sealing preparation stage, the controller receives the polyurethane foam matrix thickness parameters of the current well design and calls the numerical values ​​from the baseline library that match the thickness parameters to replace the foundation maintenance power in the formula. The default setting is used to calculate and output the compensated thermal radiation power command; the infrared radiation heating lamp controls the effective reaction heat duration of the interface according to the power command under the background of thermal capacity decay of different thicknesses, so as to offset the difference in heat dissipation caused by the thickness variation of polyurethane foam matrix and maintain the stable generation of covalent urea bond anchoring structure when continuously preparing composite materials under thickness variation conditions.

[0042] The embodiments of this application have been described above with reference to the accompanying drawings. Unless otherwise specified, the embodiments and features in the embodiments of this application can be combined with each other. This application is not limited to the specific embodiments described above. The specific embodiments described above are merely illustrative and not restrictive. Those skilled in the art can make many other forms under the guidance of this application without departing from the spirit of this application and the scope of protection of this invention, and all of these forms are within the protection scope of this application.

Claims

1. A preparation process for a non-combustible, leak-proof building material, characterized in that, The preparation process includes the following steps: Step S1: Prepare a polyurethane composition. The polyurethane composition includes polyphenyl polymethylene polyisocyanate, combined polyether, and a composite flame retardant system composed of ammonium polyphosphate, melamine, and expanded graphite. The excess isocyanate groups in the polyphenyl polymethylene polyisocyanate are controlled so that free isocyanate groups remain on the surface of the polyurethane foam matrix during the foaming stage. Step S2: Initiate the foaming reaction of the polyurethane composition and use the heat of reaction released by the foaming reaction to keep the surface temperature of the polyurethane foam matrix at 45°C to 55°C. Step S3, while the surface temperature of the polyurethane foam matrix is ​​between 45°C and 55°C, the product containing... An inorganic slurry of -aminopropyltriethoxysilane coupling agent is coated on the surface of a polyurethane foam matrix. The inorganic slurry includes a sodium silicate solution with a modulus of 2.8 to 3.2, aluminum hydroxide powder, and talc powder. Step S4, driven by the heat of reaction - The terminal amino group of the aminopropyltriethoxysilane coupling agent undergoes an addition reaction with the free isocyanate group, forming a covalent urea bond anchoring structure in situ at the interface between the organic and inorganic phases. Step S5, through - The silanol end of the aminopropyltriethoxysilane coupling agent undergoes dehydration and polycondensation with the sodium silicate network in the inorganic slurry, forming a chemically bonded interface between the polyurethane foam matrix and the inorganic coating.

2. The preparation process of a non-combustible, leak-proof building material according to claim 1, characterized in that, Step S2 further includes: Step S21: By controlling the molding thickness of the polyurethane foam matrix and the starting temperature of the foaming reaction, the effective reaction heat time domain formed on the surface of the polyurethane foam matrix is ​​made to last for 120s to 300s, and the temperature fluctuation range within the effective reaction heat time domain is within ±2℃, so that the addition reaction in step S4 crosses the reaction activation energy threshold and forms a chemical bond density of not less than 1000 bonds / μm at the interface. 2 The covalent urea bond anchoring structure.

3. The preparation process of a non-combustible, leak-proof building material according to claim 1, characterized in that, Step S1 further includes: Step S11: controlling the molar ratio of isocyanate groups to hydroxyl groups in the combined polyether to be 1.05:1 to 1.20:1, and through the over-design of stoichiometric ratio, the surface of the polyurethane foam matrix is ​​distributed with active sites for reacting with terminal amino groups in the early stage of crosslinking.

4. The preparation process of a non-combustible, leak-proof building material according to claim 1, characterized in that, Based on 100 parts by total weight of the polyurethane composition, the content of ammonium polyphosphate is 10 to 15 parts, the content of melamine is 5 to 8 parts, and the content of expanded graphite is 3 to 6 parts.

5. The preparation process of a non-combustible, leak-proof building material according to claim 1, characterized in that, In step S3, the mass ratio of each component in the inorganic slurry is: 40 to 60 parts sodium silicate solution, 15 to 25 parts aluminum hydroxide powder, and 10 to 20 parts talc.

6. The preparation process of a non-combustible, leak-proof building material according to claim 1, characterized in that, In step S3, a high-pressure airless spraying process is used for coating, with the spraying pressure set to 15MPa to 20MPa, and the cured thickness of the inorganic coating after spraying controlled to be 1.5mm to 3.0mm.

7. The preparation process of a non-combustible, leak-proof building material according to claim 1, characterized in that, Step S3 further includes: Step S31: Ultrasonic dispersion of the inorganic slurry, setting the ultrasonic frequency to 20kHz to 40kHz and the duration to 10min to 20min, to eliminate microbubbles in the inorganic slurry and improve... - The uniformity of concentration of aminopropyltriethoxysilane coupling agent in the slurry system.

8. The preparation process of a non-combustible, leak-proof building material according to claim 1, characterized in that, The preparation process also includes: Step S6: The material after step S5 is introduced into the curing environment, the temperature is set to 25℃ to 35℃, the relative humidity is 60% to 70%, and the aging time is not less than 24 hours, so that the chemical bonding interface can be structurally strengthened.

9. The preparation process of a non-combustible, leak-proof building material according to claim 1, characterized in that, The covalent urea bond anchoring structure formed in step S4 ensures that the interfacial bond strength between the inorganic coating and the polyurethane foam matrix remains at more than 80% of the initial strength under a thermal shock environment of 600℃.

Images