Fast-curing waterproof polyurea and preparation method and application thereof

Abstract

The present application relates to the technical field of polyurea production, in particular to a fast-curing waterproof polyurea, a preparation method and application thereof.The polyurea is composed of a composite system of component A isocyanate prepolymer and component B amino chain extender with a mass ratio of 1:(0.9-1.1).Component A contains modified MDI, bio-based polyether polyol, nano TiO2@Ag composite filler, etc.;component B contains amino-terminated polyether, bio-based amine chain extender, super-hydrophobic modified SiO2, etc.Through the synergistic effect of each component, the present application realizes tear resistance ≥86kN / m, no cracks at -45℃ bending, and a substantial improvement in ultraviolet aging and root puncture resistance, and is suitable for the field of building waterproofing, especially for scenarios such as roof gardens, underground pipe galleries, chemical plant floors, etc., and has excellent mechanical properties, environmental tolerance and environmental friendliness.

Description

Technical Field

[0001] This invention relates to the field of polyurea production technology, specifically to rapid-curing waterproof polyurea, its preparation method, and its applications. Background Technology

[0002] Polyurea materials hold an important position in the field of building waterproofing due to their rapid curing, high elasticity, and corrosion resistance. However, existing technologies have many problems that urgently need to be solved. Traditional polyurea struggles to balance high mechanical strength and low-temperature flexibility; its tear strength is typically no more than 50 kN / m, and it is prone to cracking at -20℃, making it unsuitable for complex temperature environments. Regarding curing control, fast-curing polyurea gel times are often ≤30 seconds, resulting in poor adaptability to the application interface and a pinhole rate exceeding 5 pins / m. 2 This severely affects the waterproofing effect.

[0003] Environmental risks cannot be ignored. Petroleum-based raw materials account for over 90%, and VOC emissions exceed 80g / L, which is inconsistent with environmental protection trends. Some products contain hexavalent chromium and other heavy metal root inhibitors, posing a carcinogenic risk. Regarding long-term effectiveness, root penetration resistance is generally less than 10 years, and blistering and peeling occur within 6 months in acidic environments such as 5% H2SO4. Furthermore, traditional polyurea has significant shortcomings in the coordination of application leveling and curing speed, biodegradability, and adhesion strength to the substrate, limiting its application in high-end waterproofing scenarios. Summary of the Invention

[0004] In view of the shortcomings of the prior art, the purpose of this invention is to provide a rapid curing waterproof polyurea. The "maze effect" formed by MXene nanosheets in component A extends the corrosion path, and the nano-TiO2@Ag composite filler enhances the antibacterial and mechanical properties. The superhydrophobic SiO2 in component B forms an air layer, and PVA / PP fibers form a three-dimensional network, which greatly improves the mechanical properties and root penetration resistance of the polyurea.

[0005] Another objective of this invention is to provide a method for preparing rapidly curing waterproof polyurea that precisely adapts to complex construction needs and solves the problems of high energy consumption, poor dispersion, and difficult curing control in traditional processes.

[0006] The third objective of this invention is to provide an application of fast-curing waterproof polyurea for use in the field of building waterproofing.

[0007] This invention is achieved using the following technical solution:

[0008] The rapidly curing waterproof polyurea comprises a composite system of component A (isocyanate prepolymer) and component B (amino chain extender) in a mass ratio of 1:(0.9-1.1); wherein,

[0009] Component A isocyanate prepolymer comprises the following raw materials in parts by weight: modified MDI: 100 parts; bio-based polyether polyol: 35-40 parts; nano-TiO2@Ag composite filler: 4-6 parts; reactive silicone leveling agent: 0.7-0.9 parts; MXene nanosheets: 0.8-1.2 parts;

[0010] The B-component amino chain extender composite system comprises the following raw materials in parts by weight: terminal amino polyether: 55-60 parts; bio-based amine chain extender: 25-30 parts; polyaspartic acid ester resin: 13-17 parts; superhydrophobic modified SiO2: 3-4 parts; PVA / PP composite fiber: 2-3 parts; zinc-based bactericide and root inhibitor: 1.8-2.2 parts; bio-based plasticizer: 4-5 parts; dopamine-modified silane coupling agent: 1.3-1.7 parts; nano-ZnO-modified recycled PVB UV shielding agent: 1-1.4 parts; boron trifluoride catalyst: 0.04-0.06 parts.

[0011] The modified MDI has an NCO% of 22-24%; the terminal amino polyether has an average molecular weight of 2000 g / mol; the bio-based plasticizer is polysaccharide anhydride; and the boron trifluoride catalyst is a boron trifluoride diethyl ether complex catalyst encapsulated in microcapsules.

[0012] The preparation method of the bio-based polyether polyol is as follows: furanyl dicarboxylic acid and glycerol are esterified in a molar ratio of 1:1.2; then epoxidized soybean oil is added, followed by ring-opening polymerization and dehydration under reduced pressure to obtain the product. Specifically, furanyl dicarboxylic acid and glycerol are taken in a molar ratio of 1:1.2, esterified at 215-220℃ for 3-4 hours, then epoxidized soybean oil is added (molar ratio: epoxidized soybean oil: furanyl dicarboxylic acid = 0.8:1), and ring-opening polymerization is carried out at 118-120℃ for 4-5 hours. The product is then dehydrated under reduced pressure until the acid value is ≤1 mgKOH / g to obtain a pale yellow viscous liquid, which is the bio-based polyether polyol.

[0013] The preparation method of the nano-TiO2@Ag composite filler is as follows: After dispersing nano-TiO2, AgNO3 is added dropwise; then reduction (0.1 mol / L sodium citrate) is performed, followed by modification with dodecyltrimethoxysilane, centrifugation and drying to obtain the final product. Specifically, nano-TiO2 is dispersed in ethanol (10% solid content), 0.1-0.12 M AgNO3 solution (Ag:TiO2 = 1:20 molar ratio) is added dropwise, reduced at 80-85℃, modified with 1-1.2% (mass percentage of silane:TiO2@Ag composite filler) of dodecyltrimethoxysilane, centrifugation and drying to obtain the nano-TiO2@Ag composite filler.

[0014] The pretreatment method for the MXene nanosheets is as follows: Ti3AlC2 is etched with HF, then ultrasonically exfoliated to obtain a monolayer of MXene, which is then grafted with γ-aminopropyltriethoxysilane. Specifically, Ti3AlC2 is etched with 38-40% HF for 48-52 hours, ultrasonically exfoliated (NMP solvent, 400W / 2 hours) to obtain a monolayer of MXene, and then grafted with γ-aminopropyltriethoxysilane (silane:MXene nanosheet mass percentage is 1:100) at 60-62℃ for 4-5 hours to obtain MXene nanosheets.

[0015] The pretreatment method for the bio-based amine chain extender is as follows: sebacic acid and diethylenetriamine are mixed and reacted, followed by vacuum distillation to obtain the product; the pretreatment method for dopamine-modified silane is as follows: dopamine hydrochloride and KH-550 silane are dissolved in methanol and reacted to obtain the product.

[0016] Specifically, the pretreatment method for bio-based amine chain extenders is as follows: Sebacic acid and diethylenetriamine are reacted at a molar ratio of 1:1.1 for 5-6 hours at 160-162℃, and the water is removed by vacuum distillation to obtain a light yellow liquid, which is the bio-based amine chain extender.

[0017] Specifically, the pretreatment method for dopamine-modified silane is as follows: dopamine hydrochloride and KH-550 silane (molar ratio 1:1) are dissolved in methanol and reacted at 42-45℃ for 12-16 hours under N2 protection. The solvent is then removed under reduced pressure.

[0018] The method for preparing the rapid-curing waterproof polyurea includes the following steps:

[0019] (1) Synthesis of component A isocyanate prepolymer:

[0020] ① After adding modified MDI to the reactor and heating it, bio-based polyether polyol is slowly added, and the reaction is carried out under nitrogen protection;

[0021] ② After the reaction is complete, cool down and add MXene nanosheet dispersion, and control the viscosity at 2500±300mPa·s (60℃) for high-speed shear;

[0022] ③ After that, nano-TiO2@Ag composite filler was added in three batches, and shearing continued;

[0023] ④ Add reactive silicone leveling agent, vacuum degas, filter, and the isocyanate prepolymer is obtained;

[0024] (2) Preparation of the amino chain extender composite system of component B:

[0025] a. Add terminal amino polyether and bio-based amine chain extender to the main reactor, heat and stir, then add polyaspartic acid ester resin and nano ZnO modified recycled PVB UV shielding agent.

[0026] b. Subsequently, the following are added sequentially: superhydrophobic modified SiO2, pretreated PVA / PP composite fiber, zinc-based bactericide and root inhibitor, and polysaccharide anhydride bio-based plasticizer; boron trifluoride diethyl ether complex catalyst is added, and the mixture is ball-milled and dispersed.

[0027] c. Then, dopamine-modified silane coupling agent is added, followed by vacuum dehydration to obtain the amino chain extender composite system.

[0028] In step ①, the temperature is raised to 58-62℃ and the reaction is carried out under nitrogen protection for 2-3 hours; in step ②, high-speed shearing is performed at 3000-3200 rpm for 40-50 minutes, and the MXene nanosheet dispersion is an MXene / NMP dispersion (concentration 3wt%); in step ③, shearing is continued for 20 minutes at 10-minute intervals; in step ④, vacuum degassing is performed at -0.098 MPa for 40 minutes, filtration is carried out using a 400-mesh sieve, and the mixture is sealed and stored.

[0029] In step a, the temperature is raised to 47-53℃, and the mixture is stirred at 200-220 rpm for 25-40 minutes. In step b, the superhydrophobic modified SiO2 has a contact angle >150°, is ball-milled to a particle size ≤5μm, and the temperature is ≤45℃ when the catalyst is added. The pretreatment method for PVA / PP fibers is plasma treatment under an argon atmosphere. In step c, the fibers are vacuum dehydrated at 70-75℃ until the moisture content is ≤0.03%. In step b, the zinc-based bactericide and root inhibitor is zinc pyrithione.

[0030] The application of the aforementioned rapid-curing waterproof polyurea is used in the field of building waterproofing. The application method is as follows: the composite system of component A isocyanate prepolymer and component B amino chain extender is added to a two-component high-pressure sprayer in a certain proportion, microcapsule delayed catalyst is added, and it is diluted with ethyl acetate solvent (5-8%) before spraying.

[0031] Specifically, the application method is as follows:

[0032] Substrate treatment:

[0033] The concrete surface is sandblasted to Sa2.5 grade (roughness 50-70μm);

[0034] Apply a 0.1% dopamine ethanol solution by total mass, with a wet film thickness of 100 μm, and cure at room temperature for 30-35 min;

[0035] Spraying parameters:

[0036] Equipment: Two-component high-pressure sprayer (static mixing pipe length ≥ 30cm);

[0037] Material temperature: Component A 65±3℃, Component B 60±3℃;

[0038] Pressure: 2000-2200psi (A:B volume ratio 1:1);

[0039] Add 0.3% by total mass of microcapsule delayed catalyst (60℃ trigger rupture);

[0040] Coating construction:

[0041] Primer: A:B diluted in a 1:1 ratio with ethyl acetate solvent, coating weight 0.15 kg / m² 2 ;

[0042] Main waterproof layer:

[0043] Apply two vertical, cross-spray coats with an interval of 5-8 minutes.

[0044] Single-layer wet film thickness 1.0 mm, total thickness ≥ 2.2 mm;

[0045] Topcoat: Fluorinated polyurethane topcoat (solid content ≥60%), application rate 0.25 kg / m² 2 ;

[0046] Curing control:

[0047] Surface drying time: 15-25s (25℃ / 50%RH);

[0048] Practical work time: ≤4 hours;

[0049] Fully cured: Can withstand loads after 7 days (23℃).

[0050] The method of adding nano-TiO2@Ag composite filler is as follows:

[0051] First time joining:

[0052] Add 30% of the total amount of nano-TiO2@Ag composite filler;

[0053] Maintain the temperature at 42-45℃, turn on high-speed shearing at 3500-3800rpm, and continue for 15-18 minutes.

[0054] Second time joining:

[0055] After a 10-minute interval, 40% of the total amount of nano-TiO2@Ag composite filler was added;

[0056] Heat to 48℃, reduce the shear rate to 3000-3200 rpm, and continue for 20-25 minutes.

[0057] Third time joining:

[0058] After another 10 minutes, add the remaining nano-TiO2@Ag composite filler;

[0059] Heat to 50-52℃, shear rate 2500-2700rpm, for 15-20min.

[0060] This invention achieves a performance breakthrough through the synergistic effect of two components, A and B: Component A is based on modified MDI, with a main chain structure constructed by compounding bio-based polyether polyols. MXene nanosheets form a "maze effect" (MXene nanosheet layers form tortuous media penetration paths >15μm) to extend the diffusion path of corrosive media. The nano-TiO2@Ag composite filler has both antibacterial and reinforcing functions. Component B uses terminal amino polyethers and bio-based amine chain extenders to regulate reaction activity. Superhydrophobic SiO2 constructs a surface air layer to reduce interfacial energy. PVA / PP composite fibers form a three-dimensional network to resist mechanical penetration. Microcapsule-encapsulated boron trifluoride catalysts achieve precise control of curing.

[0061] Synergistic corrosion protection of MXene / superhydrophobic SiO2: MXene nanosheets (layered structure with lateral dimensions of 1-5μm) form a "maze effect" in the coating, extending the diffusion path of corrosive media; superhydrophobic SiO2 (contact angle of 152°) builds an air layer on the surface, reducing interfacial energy.

[0062] Ag-TiO2 / PVA fiber for root penetration resistance: Ag + Inhibits the growth of root meristems; TiO2 photocatalytically degrades root exudates; PVA fibers (tensile strength 1.2 GPa) form a three-dimensional network to resist mechanical penetration.

[0063] Paraffin coating with boron trifluoride (triggered at 60°C) achieves "leveling during construction (viscosity < 500 cps) → explosive polymerization upon contact with substrate".

[0064] Low-temperature toughness of bio-based plasticizers / dopamine coupling agents: Polysaccharide anhydride plasticizers reduce the glass transition temperature of polymers (Tg from -25℃ to -42℃); dopamine coupling agents enhance the efficiency of interfacial stress transfer.

[0065] Compared with the prior art, the beneficial effects of the present invention are:

[0066] (1) The corrosion path is extended by the "maze effect" formed by MXene nanosheets in component A, and the antibacterial and mechanical properties are enhanced by nano-TiO2@Ag composite filler; the superhydrophobic SiO2 in component B forms an air layer, and PVA / PP fibers form a three-dimensional network. As a result, the product has a tear strength of 86kN / m and no cracks at -45℃, ΔE≤1 after 3000h of UV aging, root penetration resistance grade A, and VOC≤4.2g / L, taking into account both high performance and environmental protection.

[0067] (2) The 50℃ low-temperature acid catalysis process reduces energy consumption by 40%, and the grafting rate of MXene nanosheets exceeds 85%. After three steps of addition and shearing treatment, the composite filler is evenly dispersed and there is no sedimentation after 6 months of storage. The microcapsule-encapsulated catalyst allows the gelation time to be adjusted to ±3s, which can be precisely adapted to complex construction needs and solves the problems of high energy consumption, poor dispersion and difficult curing control of traditional processes.

[0068] (3) Optimize spraying parameters for scenarios such as roof gardens and underground pipe corridors to form a seamless coating with an adhesion of 7.2MPa, surface drying time of 15-25s, and hard drying time of ≤4h. It has zero penetration in roof gardens for 25 years, can withstand 0.9MPa dynamic water pressure in underground pipe corridors, and has an acid weight loss of only 0.08% in chemical plant floors. Its service life is more than 400% longer than that of traditional materials, making it suitable for the stringent requirements of multiple fields. Detailed Implementation

[0069] To make the objectives and technical solutions of this invention clearer, the invention will be further described in detail below.

[0070] Modified MDI: Wanhua Chemical Group Co., Ltd., PM-200 (NCO%=23.5%), functionality 2.7;

[0071] Amino-terminated polyether: Amino-terminated polyether D2000, BASF AG, Baxxodur® EC301, amine value 110 mg KOH / g;

[0072] Polyaspartic acid ester resin: Covestro AG, Desmophen® NH1420, viscosity 2500 mPa·s (25°C);

[0073] Silicone leveling agent: Evonik Industries, TEGO® Flow370, reactive, molecular weight 2000;

[0074] Zinc-based fungicide and root inhibitor: Zinc pyrithione, Lanxess Group, Preventol® ZP50, zinc content 22.5%;

[0075] Superhydrophobic SiO2: Cabot Corporation, L-90 (hydrophobic modified), specific surface area 90 m² 2 / g, contact angle 152°;

[0076] PVA / PP composite fiber: Kuraray Corporation, Kuralon™ RFN-05, PVA / PP=7:3, length 3mm;

[0077] Recycled PVB-based UV absorber: BASF AG, BASF Uvinul® 3030, transmittance ≥90%, melting point 170°C;

[0078] Boron trifluoride catalyst: paraffin-coated boron trifluoride diethyl ether complex microcapsules, Dynapol® S-1352, Evonik Industries, BF3·(C2H5)2O;

[0079] Petroleum-based polyether polyols: Dow Chemical Technology (Tianjin) Co., Ltd., Voranol TM 4701;

[0080] PVC membrane: Beijing Oriental Yuhong Waterproof Technology Co., Ltd., Polyvinyl chloride (PVC) membrane, PV-203 type PVC waterproof membrane (1.5mm thick).

[0081] Polyurethane coating: BASF AG, Elastocoat® 6600 (two-component);

[0082] Polysulfide sealant: Sikaflex®-15LM (two-component);

[0083] Silicone sealant: Dow Corning (Shanghai) Co., Ltd., DC-983 (neutral curing type);

[0084] Epoxy coal tar pitch: Hempagrins (Yantai) Co., Ltd., Hempadur® 8566 (A:B=4:1);

[0085] Glass flake putty: Showa Denko Co., Ltd., Shokon® LP-300 (vinyl ester).

[0086] In the examples and comparative examples, the preparation methods of some raw materials are as follows:

[0087] The preparation method of bio-based polyether polyol is as follows: furanyl dicarboxylic acid and glycerol are mixed in a molar ratio of 1:1.2 and esterified at 220℃ for 3 hours. Then, epoxidized soybean oil (molar ratio: epoxidized soybean oil: furanyl dicarboxylic acid = 0.8:1) is added, and ring-opening polymerization is carried out at 120℃ for 4 hours. The mixture is then dehydrated under reduced pressure until the acid value is ≤1mgKOH / g to obtain a light yellow viscous liquid, which is the bio-based polyether polyol with a hydroxyl value of 56mgKOH / g.

[0088] The preparation method of nano-TiO2@Ag composite filler is as follows: nano-TiO2 is dispersed in ethanol (solid content 10%), 0.1-0.12M AgNO3 solution is added dropwise (Ag:TiO2=1:20 molar ratio), reduced at 80℃, modified with 1% (silane: TiO2@Ag composite filler mass percentage) dodecyltrimethoxysilane, centrifuged and dried to obtain nano-TiO2@Ag composite filler.

[0089] The pretreatment method for MXene nanosheets is as follows: Ti3AlC2 is etched with 38-40%HF for 48h, ultrasonically exfoliated (NMP solvent, 400W / 2h) to obtain monolayer MXene, and then grafted with γ-aminopropyltriethoxysilane (silane:MXene nanosheet mass percentage is 1:100) at 60℃ for 4h to obtain MXene nanosheets.

[0090] The pretreatment method for the bio-based amine chain extender is as follows: Sebacic acid and diethylenetriamine are reacted at a molar ratio of 1:1.1 for 5 hours at 160°C. The water is removed by vacuum distillation to obtain a light yellow liquid, which is the bio-based amine chain extender with an amine value of 320 mg KOH / g.

[0091] The pretreatment method for dopamine-modified silane is as follows: dopamine hydrochloride and KH-550 silane (molar ratio 1:1) are dissolved in methanol and reacted at 45°C for 12 hours under N2 protection. The solvent is then removed under reduced pressure.

[0092] The method for processing nano-ZnO modified recycled PVB UV shielding agent is as follows: Dissolve 100 parts of Eslek™ R-1000 in methyl ethyl ketone (30% solid content); add 15 parts of nano-zinc oxide with a particle size of 30 nm, ultrasonically disperse at 500 W for 1 h, add 3 parts of silane coupling agent KH-560, and spray dry to obtain the product. The UV shielding rate is tested to be ≥98%.

[0093] The method of adding nano-TiO2@Ag composite filler is as follows:

[0094] First time joining:

[0095] Add 30% of the total amount of nano-TiO2@Ag composite filler;

[0096] Maintain the temperature at 45℃, turn on high-speed shearing at 3500rpm, and continue for 15 minutes;

[0097] Test results: The system viscosity increased from 850 mPa·s to 1200 mPa·s (monitored by Hacker rheometer).

[0098] Second time joining:

[0099] After a 10-minute interval, 40% of the total amount of nano-TiO2@Ag composite filler was added;

[0100] The temperature was increased to 48°C, and the shear rate was reduced to 3000 rpm for 20 minutes.

[0101] Testing: Laser particle size analyzer confirmed that the particle size D50 is 180nm.

[0102] Third time joining:

[0103] After another 10 minutes, add the remaining nano-TiO2@Ag composite filler;

[0104] Heat to 50℃, shear rate 2500 rpm, for 15 min;

[0105] Test results: Conductivity remained stable at 5 μS / cm.

[0106] Example 1

[0107] The rapid-curing waterproof polyurea comprises a composite system of component A (isocyanate prepolymer) and component B (amino chain extender) in a mass ratio of 1:0.9; wherein,

[0108] Component A isocyanate prepolymer comprises the following raw materials in parts by weight: modified MDI: 100 parts; bio-based polyether polyol: 35 parts; nano-TiO2@Ag composite filler: 4 parts; reactive silicone leveling agent: 0.7 parts; MXene nanosheets: 0.8 parts;

[0109] The B-component amino chain extender composite system comprises the following raw materials in parts by weight: terminal amino polyether: 55 parts; bio-based amine chain extender: 25 parts; polyaspartic acid ester resin: 13 parts; superhydrophobic modified SiO2: 3 parts; PVA / PP composite fiber: 2 parts; zinc-based bactericide and root inhibitor: 1.8 parts; bio-based plasticizer: 4 parts; dopamine-modified silane coupling agent: 1.3 parts; nano-ZnO modified recycled PVB UV shielding agent: 1 part; boron trifluoride catalyst: 0.04 parts.

[0110] The average molecular weight of the amino-terminated polyether is 2000 g / mol; the bio-based plasticizer is polysaccharide anhydride; and the boron trifluoride catalyst is microencapsulated.

[0111] A method for preparing rapidly curing waterproof polyurea includes the following steps:

[0112] (1) Synthesis of component A isocyanate prepolymer:

[0113] ① After adding modified MDI to the reactor and heating it, bio-based polyether polyol is slowly added, and the reaction is carried out under nitrogen protection;

[0114] ② After the reaction is complete, cool down and add MXene nanosheet dispersion, control the viscosity at 2200 mPa·s (60℃), and perform high-speed shearing;

[0115] ③ After that, nano-TiO2@Ag composite filler was added in three batches, and shearing continued;

[0116] ④ Add reactive silicone leveling agent, vacuum degas, filter, and the isocyanate prepolymer is obtained;

[0117] (2) Preparation of the amino chain extender composite system of component B:

[0118] a. Add terminal amino polyether and bio-based amine chain extender to the main reactor, heat and stir, then add polyaspartic acid ester resin and nano ZnO modified recycled PVB UV shielding agent.

[0119] b. Subsequently, the following are added sequentially: superhydrophobic modified SiO2, pretreated PVA / PP composite fiber, zinc-based bactericide and root inhibitor, and polysaccharide anhydride bio-based plasticizer; boron trifluoride diethyl ether complex catalyst is added, and the mixture is ball-milled and dispersed.

[0120] c. Then, dopamine-modified silane coupling agent is added, followed by vacuum dehydration to obtain the amino chain extender composite system.

[0121] In step ①, the temperature was raised to 58℃ and the reaction was carried out under nitrogen protection for 2 hours; in step ②, the high-speed shearing was performed at 3000 rpm for 40 minutes, and the MXene nanosheet dispersion was an MXene / NMP dispersion (concentration 3wt%); in step ③, the shearing was continued for 20 minutes at 10-minute intervals; in step ④, the sample was degassed under vacuum at -0.098 MPa for 40 minutes, filtered through a 400-mesh sieve, and stored in a sealed container.

[0122] In step a, the temperature is raised to 50°C and stirred at 200 rpm for 25 min; in step b, the superhydrophobic modified SiO2 has a contact angle of 150° and is dispersed by ball milling to a particle size of 5 μm; the pretreatment method for PVA / PP fibers is: PVA / PP fibers are plasma treated in an argon atmosphere; in step c, the moisture content is reduced to 0.03% under vacuum at 70°C.

[0123] Example 2

[0124] The rapid-curing waterproof polyurea comprises a composite system of component A (isocyanate prepolymer) and component B (amino chain extender) in a 1:1 mass ratio; wherein,

[0125] Component A isocyanate prepolymer comprises the following raw materials in parts by weight: modified MDI: 100 parts; bio-based polyether polyol: 38 parts; nano TiO2@Ag composite filler: 5 parts; reactive silicone leveling agent: 0.8 parts; MXene nanosheets: 1 part;

[0126] The B-component amino chain extender composite system comprises the following raw materials in parts by weight: terminal amino polyether: 58 parts; bio-based amine chain extender: 28 parts; polyaspartic acid ester resin: 15 parts; superhydrophobic modified SiO2: 3 parts; PVA / PP composite fiber: 3 parts; zinc-based bactericide and root inhibitor: 2 parts; bio-based plasticizer: 4 parts; dopamine-modified silane coupling agent: 1.5 parts; nano-ZnO modified recycled PVB UV shielding agent: 1.2 parts; boron trifluoride catalyst: 0.05 parts.

[0127] The average molecular weight of the amino-terminated polyether is 2000 g / mol; the bio-based plasticizer is polysaccharide anhydride; and the boron trifluoride catalyst is microencapsulated.

[0128] A method for preparing rapidly curing waterproof polyurea includes the following steps:

[0129] (1) Synthesis of component A isocyanate prepolymer:

[0130] ① After adding modified MDI to the reactor and heating it, bio-based polyether polyol is slowly added, and the reaction is carried out under nitrogen protection;

[0131] ② After the reaction is complete, cool down and add MXene nanosheet dispersion, control the viscosity at 2500 mPa·s (60℃), and perform high-speed shearing;

[0132] ③ After that, nano-TiO2@Ag composite filler was added in three batches, and shearing continued;

[0133] ④ Add reactive silicone leveling agent, vacuum degas, filter, and the isocyanate prepolymer is obtained;

[0134] (2) Preparation of the amino chain extender composite system of component B:

[0135] a. Add terminal amino polyether and bio-based amine chain extender to the main reactor, heat and stir, then add polyaspartic acid ester resin and nano ZnO modified recycled PVB UV shielding agent.

[0136] b. Subsequently, the following are added sequentially: superhydrophobic modified SiO2, pretreated PVA / PP composite fiber, zinc-based bactericide and root inhibitor, and polysaccharide anhydride bio-based plasticizer; boron trifluoride diethyl ether complex catalyst is added, and the mixture is ball-milled and dispersed.

[0137] c. Then, dopamine-modified silane coupling agent is added, followed by vacuum dehydration to obtain the amino chain extender composite system.

[0138] In step ①, the temperature was raised to 60℃ and the reaction was carried out under nitrogen protection for 2 hours; in step ②, the high-speed shearing was performed at 3200 rpm for 45 minutes, and the MXene nanosheet dispersion was an MXene / NMP dispersion (concentration 3wt%); in step ③, the shearing was continued for 20 minutes at 10-minute intervals; in step ④, the sample was degassed under vacuum at -0.098 MPa for 40 minutes, filtered through a 400-mesh sieve, and stored in a sealed container.

[0139] In step a, the temperature is raised to 50℃ and stirred at 210 rpm for 32 min; in step b, the superhydrophobic modified SiO2 has a contact angle of 150° and is dispersed by ball milling to a particle size of 5 μm; the pretreatment method for PVA / PP fibers is: PVA / PP fibers are plasma treated in an argon atmosphere; in step c, the moisture content is reduced to 0.03% under vacuum at 72℃.

[0140] Example 3

[0141] The rapid-curing waterproof polyurea comprises a composite system of component A (isocyanate prepolymer) and component B (amino chain extender) in a mass ratio of 1:1.1; wherein,

[0142] Component A isocyanate prepolymer comprises the following raw materials in parts by weight: modified MDI: 100 parts; bio-based polyether polyol: 40 parts; nano-TiO2@Ag composite filler: 6 parts; reactive silicone leveling agent: 0.9 parts; MXene nanosheets: 1.2 parts;

[0143] The B-component amino chain extender composite system comprises the following raw materials in parts by weight: terminal amino polyether: 60 parts; bio-based amine chain extender: 30 parts; polyaspartic acid ester resin: 17 parts; superhydrophobic modified SiO2: 4 parts; PVA / PP composite fiber: 3 parts; zinc-based bactericide and root inhibitor: 2.2 parts; bio-based plasticizer: 5 parts; dopamine-modified silane coupling agent: 1.7 parts; nano-ZnO-modified recycled PVB UV shielding agent: 1.4 parts; boron trifluoride catalyst: 0.06 parts.

[0144] The average molecular weight of the amino-terminated polyether is 2000 g / mol; the bio-based plasticizer is polysaccharide anhydride; and the boron trifluoride catalyst is microencapsulated.

[0145] A method for preparing rapidly curing waterproof polyurea includes the following steps:

[0146] (1) Synthesis of component A isocyanate prepolymer:

[0147] ① After adding modified MDI to the reactor and heating it, bio-based polyether polyol is slowly added, and the reaction is carried out under nitrogen protection;

[0148] ② After the reaction is complete, cool down and add MXene nanosheet dispersion, control the viscosity at 2800 mPa·s (60℃), and perform high-speed shearing;

[0149] ③ After that, nano-TiO2@Ag composite filler was added in three batches, and shearing continued;

[0150] ④ Add reactive silicone leveling agent, vacuum degas, filter, and the isocyanate prepolymer is obtained;

[0151] (2) Preparation of the amino chain extender composite system of component B:

[0152] a. Add terminal amino polyether and bio-based amine chain extender to the main reactor, heat and stir, then add polyaspartic acid ester resin and nano ZnO modified recycled PVB UV shielding agent.

[0153] b. Subsequently, the following are added sequentially: superhydrophobic modified SiO2, pretreated PVA / PP composite fiber, zinc-based bactericide and root inhibitor, and polysaccharide anhydride bio-based plasticizer; boron trifluoride diethyl ether complex catalyst is added, and the mixture is ball-milled and dispersed.

[0154] c. Then, dopamine-modified silane coupling agent is added, followed by vacuum dehydration to obtain the amino chain extender composite system.

[0155] In step ①, the temperature was raised to 62℃ and the reaction was carried out under nitrogen protection for 3 hours; in step ②, the high-speed shearing was performed at 3200 rpm for 50 minutes, and the MXene nanosheet dispersion was an MXene / NMP dispersion (concentration 3wt%); in step ③, the shearing was continued for 20 minutes at 10-minute intervals; in step ④, the sample was degassed under vacuum at -0.098 MPa for 40 minutes, filtered through a 400-mesh sieve, and stored in a sealed container.

[0156] In step a, the temperature is raised to 53℃ and stirred at 220 rpm for 40 min; in step b, the superhydrophobic modified SiO2 has a contact angle of 150° and is dispersed by ball milling to a particle size of 5 μm; the pretreatment method for PVA / PP fibers is: PVA / PP fibers are plasma treated in an argon atmosphere; in step c, the moisture content is reduced to 0.03% under vacuum at 75℃.

[0157] Comparative Example 1

[0158] Compared with Example 2, the difference is that MXene nanosheets were not added, and the amount of nano-TiO2@Ag composite filler added was 6.5 parts.

[0159] Comparative Example 2

[0160] Compared with Example 2, the difference is that no superhydrophobic SiO2 was added, and the amount of nano-ZnO modified recycled PVB UV shielding agent added was 1.8 parts.

[0161] Comparative Example 3

[0162] The difference compared to Example 2 is that no PVA / PP composite fiber was added, and the amount of bio-based plasticizer added was 5.5 parts.

[0163] Comparative Example 4

[0164] The difference compared to Example 2 is that no dopamine-modified silane coupling agent was added, and the amount of ordinary KH-550 silane coupling agent added was 1.5 parts.

[0165] Comparative Example 5

[0166] The difference from Example 2 is that the bio-based polyether polyol is replaced with a petroleum-based polyether polyol.

[0167] The data from the above examples and comparative examples were tested: all performance tests were conducted after components A and B were fully mixed, and the mixing process strictly simulated actual construction conditions: mixing standard (ASTM D6947).

[0168] The mixing equipment used was a high-pressure impact mixer (GracoGX-8) with a pressure ratio of A:B=1:1 (hydraulic drive). The material temperatures were: component A 65℃, component B 60℃; mixing chamber pressure 2000psi; 24-element spiral static mixing tube (30cm in length); viscosity changes were monitored immediately after mixing using a cone-plate rheometer to confirm a gel time of 18±3s (25℃); mixing uniformity was verified by SEM observation of sample sections (5000x magnification), requiring a phase region size of 5μm, and detection using the fluorescent tracer method, with a mixing non-uniformity ≤1.5%; all test specimens were cast within 20s after mixing, and the curing conditions were 23℃ / 50%RH.

[0169] The test data for Examples 1-3 and Comparative Examples 1-5 are shown in Table 1.

[0170] Table 1: Test data of Examples 1-3 and Comparative Examples 1-5

[0171]

[0172] Note: Root penetration resistance grades: Grade A (root inhibition rate >99%), Grade B (>95%), Grade C (>90%).

[0173] As shown in Table 1, Example 2 exhibits outstanding performance in multiple aspects, including a tensile strength of 27.5 MPa, a tear strength of 86 kN / m, a Shore D hardness of 68, a weight gain of 0.5% after 60 days with 10% H2SO4, a weight gain of 0.3% after 60 days with 5% NaOH, a ΔE of 0.8 after 3000 h of UV aging, a root penetration resistance grade of A, a bond strength of 7.2 MPa, passing the low-temperature flexibility test at -45℃, a VOC content of 3.8 g / L, and a biodegradation rate of 45% after 180 days. In comparison, the performance of the comparative examples without key components (such as MXene nanosheets and superhydrophobic SiO2) is significantly reduced. For example, Comparative Example 1, without MXene nanosheets, shows a weight gain of 3.2% after 10% H2SO4; Comparative Example 3, without PVA / PP composite fibers, has a tensile strength of only 19.2 MPa, demonstrating the synergistic effect of the components on performance improvement.

[0174] Application Example 1

[0175] The fast-curing waterproof polyurea obtained in Example 2 was used for waterproofing roof gardens.

[0176] The application method of rapid curing waterproof polyurea is as follows:

[0177] Substrate treatment:

[0178] The concrete surface is sandblasted to Sa2.5 grade (roughness 60μm);

[0179] The total mass of the coating solution was 0.1% dopamine ethanol solution, the wet film thickness was 100 μm, and the curing time was 30 min at room temperature.

[0180] Spraying parameters:

[0181] Equipment: Two-component high-pressure sprayer (static mixing pipe length ≥ 30cm);

[0182] Material temperature: Component A 65℃, Component B 60℃;

[0183] Pressure: 2200psi (A:B volume ratio 1:1);

[0184] Add 0.3% by total mass of microcapsule delayed catalyst (60℃ trigger rupture);

[0185] Coating construction:

[0186] Primer: A:B diluted in a 1:1 ratio with ethyl acetate solvent, coating weight 0.15 kg / m² 2 ;

[0187] Main waterproof layer:

[0188] Two vertically cross-sprayed coats, with an 8-minute interval between coats;

[0189] The thickness of a single wet film is 1.0 mm, and the total thickness is 2.2 mm.

[0190] Topcoat: Fluorinated polyurethane topcoat (60% solids content), application rate 0.25 kg / m² 2 ;

[0191] Curing control:

[0192] Surface drying time: 20s (25℃ / 50%RH);

[0193] Practical work time: 4 hours;

[0194] Fully cured: Can withstand loads after 7 days (23℃).

[0195] Application Example 2

[0196] The rapid-curing waterproof polyurea obtained in Example 2 was used for sealing joints in underground pipe corridors.

[0197] The application method of rapid curing waterproof polyurea is as follows:

[0198] Surface preparation: sandblasting to Sa2.5 grade, roughness of 70μm, crack grouting with epoxy resin, compressive strength of 50MPa, and moisture content of 8%;

[0199] Primer application: Apply dopamine ethanol solution using a short-pile roller (15mm nap), at a rate of 0.2 kg / m². 2 Surface dry for 30 minutes;

[0200] Joint reinforcement: 200g / m 2 The polyester nonwoven fabric is embedded in the seam, with a width of 300mm and an overlap of 50mm;

[0201] Polyurea spraying: A:B=1:1.03; Material temperature A: 65℃ / B: 60℃; Pressure 2000psi; Spray distance 50cm, moving speed 0.5m / s; Equipment: GracoReactor E-30 (two-component main unit)

[0202] Thickness control: Joint area: 3.0mm (divided into 2 layers); Flat area: 2.0mm (1 layer); Allowable deviation ±0.2mm.

[0203] Application Example 3

[0204] The rapid-curing waterproof polyurea obtained in Example 2 was used for corrosion protection of chemical plant flooring.

[0205] The application method for rapid curing waterproof polyurea is the same as in Application Example 1.

[0206] Application Comparative Example 1

[0207] The difference from Application Example 1 is that the rapid-curing waterproof polyurea obtained in Example 2 is replaced with PVC roll material.

[0208] Application Comparative Example 2

[0209] The difference from Application Example 1 is that the rapid-curing waterproof polyurea obtained in Example 2 is replaced with a polyurethane coating.

[0210] Application Comparative Example 3

[0211] The difference from Application Example 2 is that the rapid-curing waterproof polyurea obtained in Example 2 is replaced with polysulfide sealant.

[0212] Application Comparative Example 4

[0213] The difference from Application Example 2 is that the rapid-curing waterproof polyurea obtained in Example 2 is replaced with silicone sealant.

[0214] Application Comparative Example 5

[0215] The difference from Application Example 3 is that the rapid-curing waterproof polyurea obtained in Example 2 is replaced with epoxy coal tar.

[0216] Application Comparative Example 6

[0217] The difference from Application Example 3 is that the rapid-curing waterproof polyurea obtained in Example 2 is replaced with glass flake putty.

[0218] Test conditions:

[0219] Roof garden (EN13948:2007)

[0220] Substrate: C30 concrete slab (300×300×50mm), sandblasted to Sa2.5 grade (roughness 70μm);

[0221] Coating: Formulation of Example 2, total thickness 2.2 mm (fluorine-containing topcoat);

[0222] test:

[0223] Root penetration tolerance: Planted moso bamboo (root penetration force 3MPa), and the penetration depth was observed after 2 years by cutting it open;

[0224] Thermal aging: 70℃ oven + freeze-thaw cycle (-20℃-25℃), tensile strength retention rate is tested every 240 hours;

[0225] Water accumulation test: Immerse in 40℃ water at a depth of 30cm, and measure weight gain and leakage every 30 days.

[0226] Underground utility tunnel joints (GB / T13477.8-2017)

[0227] Joint model: Concrete joint width 20mm, with a pre-set displacement capacity of ±25% (hydraulic drive);

[0228] Coating: Spray 3.0mm polyurea (Formulation of Example 3) into the joint area;

[0229] test:

[0230] Dynamic water pressure: 0.8MPa water pressure (fluctuation ±0.1MPa / s), leakage is detected after 500,000 cycles;

[0231] Chloride ion permeation: 5% NaCl solution, 60V DC current for 6 hours to measure the amount of charge passing through (coulomb value).

[0232] Mold test: Inoculation with Aspergillus niger (10) 6 (CFU / mL), and assess growth grade after 28 days.

[0233] Chemical plant flooring (GB / T9274-2018)

[0234] Specimen: Steel plate (150×150×2mm), sandblasted to Sa2.5 grade, coating thickness 2.0mm;

[0235] Corrosive environment: 5% H2SO4 solution (40℃), semi-immersed state (liquid surface / air interface);

[0236] test:

[0237] Weight loss rate: Mass loss measured after 6 months;

[0238] Abrasion resistance: CS-17 grinding wheel, 1000g load, weight loss (mg) at 500 revolutions;

[0239] Impact resistance: Impact test with a 1kg steel ball dropped from 1.5m, and observe for cracks.

[0240] The test data for Application Example 1 and Application Comparative Examples 1-2 are shown in Table 2;

[0241] The test data for Application Example 2 and Application Comparative Examples 3-4 are shown in Table 3;

[0242] The test data for Application Example 3 and Application Comparative Examples 5-6 are shown in Table 4.

[0243] Table 2: Test data for Application Example 1 and Comparative Examples 1-2 (2 years of testing)

[0244]

[0245] As shown in Table 2, Example 2 exhibits outstanding performance in multiple aspects, including a tensile strength of 27.5 MPa, a tear strength of 86 kN / m, a Shore D hardness of 68, a weight gain of 0.5% after 60 days with 10% H2SO4, a weight gain of 0.3% after 60 days with 5% NaOH, a ΔE of 0.8 after 3000 h of UV aging, a root penetration resistance grade of A, a bond strength of 7.2 MPa, passing the low-temperature flexibility test at -45℃, a VOC content of 3.8 g / L, and a 28-day biodegradation rate of 45%. In comparison, the performance of the comparative examples without key components (MXene nanosheets, superhydrophobic SiO2, etc.) is significantly reduced. For example, Comparative Example 1, without MXene nanosheets, showed a weight gain of 3.2% after 10% H2SO4; Comparative Example 3, without PVA / PP composite fibers, had a tensile strength of only 19.2 MPa, demonstrating the synergistic effect of the components on performance improvement.

[0246] Table 3: Test data for Application Example 2 and Comparative Examples 3-4 (500,000 cycles at 0.8 MPa water pressure)

[0247]

[0248] Table 3 shows that in Application Example 2, under 500,000 cycles of 0.8 MPa water pressure, the leakage pressure point is >0.9 MPa, the displacement fatigue life is >500,000 cycles, and the chloride ion permeation is 85 coulombs. In Comparative Example 3, the leakage pressure point is 0.35 MPa, the displacement fatigue life is 80,000 cycles, and the chloride ion permeation is 4200 coulombs; in Comparative Example 4, the leakage pressure point is 0.52 MPa, the displacement fatigue life is 150,000 cycles, and the chloride ion permeation is 2800 coulombs. This demonstrates that the proposed solution far surpasses traditional sealing materials in terms of water pressure resistance, fatigue resistance, and impermeability.

[0249] Table 4: Test data for Application Example 3 and Comparative Examples 5-6 (immersion in 5% H2SO4 for 6 months)

[0250]

[0251] Table 4 shows that Application Example 3, after immersion in 5% H2SO4 for 6 months, exhibited a weight loss of 0.08%, an abrasion resistance of 12 mg / 1000 rpm, and no cracks after a 1.5m drop ball impact. Comparative Example 5 showed a weight loss of 1.85% and blistering / peeling, an abrasion resistance of 210 mg / 1000 rpm, and fracture after a 0.3m drop ball impact; Comparative Example 6 showed a weight loss of 0.45% and edge corrosion, an abrasion resistance of 65 mg / 1000 rpm, and fracture after a 0.3m drop ball impact. These results demonstrate that this solution exhibits excellent performance in acid corrosion resistance, abrasion resistance, and impact resistance.

Claims

1. A rapid-curing waterproof polyurea, characterized in that, The system comprises a composite system of component A (isocyanate prepolymer) and component B (amino chain extender) in a mass ratio of 1:(0.9-1.1); wherein, Component A isocyanate prepolymer comprises the following raw materials in parts by weight: modified MDI: 100 parts; bio-based polyether polyol: 35-40 parts; nano-TiO2@Ag composite filler: 4-6 parts; reactive silicone leveling agent: 0.7-0.9 parts; MXene nanosheets: 0.8-1.2 parts; The B-component amino chain extender composite system comprises the following raw materials in parts by weight: terminal amino polyether: 55-60 parts; bio-based amine chain extender: 25-30 parts; polyaspartic acid ester resin: 13-17 parts; superhydrophobic modified SiO2: 3-4 parts; PVA / PP composite fiber: 2-3 parts; zinc-based bactericide and root inhibitor: 1.8-2.2 parts; bio-based plasticizer: 4-5 parts; dopamine-modified silane coupling agent: 1.3-1.7 parts; nano-ZnO-modified recycled PVB UV shielding agent: 1-1.4 parts; boron trifluoride catalyst: 0.04-0.06 parts; The preparation method of the bio-based polyether polyol is as follows: furanyl dicarboxylic acid and glycerol are esterified in a molar ratio of 1:1.2; then epoxidized soybean oil is added, ring-opening polymerization is carried out, and then dehydration is performed under reduced pressure to obtain the product.

2. The rapid-curing waterproof polyurea according to claim 1, characterized in that, The modified MDI has an NCO% of 22-24%; the terminal amino polyether has an average molecular weight of 2000 g / mol; the bio-based plasticizer is polysaccharide anhydride; and the boron trifluoride catalyst is a boron trifluoride diethyl ether complex encapsulated in microcapsules.

3. The rapid-curing waterproof polyurea according to claim 1, characterized in that, The preparation method of the nano-TiO2@Ag composite filler is as follows: after the nano-TiO2 is dispersed, AgNO3 is added dropwise; then it is reduced, modified with dodecyltrimethoxysilane, and dried by centrifugation to obtain the filler.

4. The rapid-curing waterproof polyurea according to claim 1, characterized in that, The pretreatment method for the MXene nanosheets is as follows: Ti3AlC2 is etched by HF, ultrasonically exfoliated to obtain a monolayer of MXene, and then grafted with γ-aminopropyltriethoxysilane.

5. The rapid-curing waterproof polyurea according to claim 1, characterized in that, The pretreatment method for the bio-based amine chain extender is as follows: sebacic acid and diethylenetriamine are mixed and reacted, followed by vacuum distillation to obtain the product; the pretreatment method for dopamine-modified silane is as follows: dopamine hydrochloride and KH-550 silane are dissolved in methanol and reacted to obtain the product.

6. A method for preparing a rapid-curing waterproof polyurea according to any one of claims 1-5, characterized in that, Includes the following steps: (1) Synthesis of component A isocyanate prepolymer: ① After adding modified MDI to the reactor and heating it, bio-based polyether polyol is slowly added and the reaction is carried out under nitrogen protection; ② After the reaction is complete, the temperature is lowered and the MXene nanosheet dispersion is added, followed by high-speed shearing; ③ After that, nano-TiO2@Ag composite filler was added in three batches, and shearing continued; ④ Add reactive silicone leveling agent, vacuum degas, filter, and the isocyanate prepolymer is obtained; (2) Preparation of the amino chain extender composite system of component B: a. Add terminal amino polyether and bio-based amine chain extender to the main reactor, heat and stir, then add polyaspartic acid ester resin and nano ZnO modified recycled PVB UV shielding agent; b. Then, add the following in sequence: superhydrophobic modified SiO2, pretreated PVA / PP composite fiber, zinc-based bactericide and root inhibitor, and bio-based plasticizer; add boron trifluoride catalyst and disperse by ball milling. c. Then, dopamine-modified silane coupling agent is added, followed by vacuum dehydration to obtain the amino chain extender composite system.

7. The method for preparing rapid-curing waterproof polyurea according to claim 6, characterized in that, In step ①, the temperature is raised to 58-62℃ and the reaction is carried out under nitrogen protection for 2-3 hours; in step ②, high-speed shearing is performed at 3000-3200 rpm for 40-50 minutes, and the MXene nanosheet dispersion is an MXene / NMP dispersion; in step ③, shearing is continued for 20 minutes at 10-minute intervals; in step ④, vacuum degassing is performed at -0.098 MPa for 40 minutes, filtration is carried out using a 400-mesh sieve, and the mixture is sealed and stored.

8. The method for preparing rapid-curing waterproof polyurea according to claim 6, characterized in that, In step a, the temperature is raised to 47-53℃ and stirred at 200-220 rpm for 25-40 min; in step b, the superhydrophobic modified SiO2 has a contact angle >150° and is ball-milled to disperse the particle size ≤5μm; the pretreatment method for PVA / PP fibers is: PVA / PP fibers are plasma treated in an argon atmosphere; in step c, vacuum dehydration is carried out at 70-75℃ until the moisture content is ≤0.03%.

9. An application of the rapid-curing waterproof polyurea according to any one of claims 1-5, characterized in that, For use in building waterproofing, the application method is as follows: add the composite system of component A isocyanate prepolymer and component B amino chain extender to a two-component high-pressure sprayer in a certain proportion, add microcapsule delayed catalyst, dilute with ethyl acetate solvent, and then spray.

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