Waterproof material for building outer wall and preparation method thereof

Abstract

This invention relates to the field of waterproof materials technology, and discloses a waterproof material for building exterior walls and its preparation method. The epoxidized soybean oil acrylate molecule contains active hydroxyl groups and flexible fatty acid long-chain structures, which react sequentially with isocyanate groups and epoxy resin to form an interpenetrating cross-linked network structure. The flexible long-chain structure can increase dispersion in the system, enhance interpenetration within the material, and improve the density between materials. The organosilicon in the organosilicone fluorine chain extender prevents water penetration by forming a dense silicon oxide protective film on the material surface. The organofluorine itself is hydrophobic and has good surface tension, which can prevent water from penetrating into the material, thereby improving the waterproof performance of the building material. The material prepared by this invention can create a skin-like waterproof barrier for building exterior walls, combining economic and environmental characteristics, and has broad prospects for large-scale industrial application.

Description

Technical Field

[0001] This invention relates to the field of waterproof materials technology, specifically to a waterproof material for building exterior walls and its preparation method. Background Technology

[0002] Currently, most buildings are high-rises, with continuously increasing building areas and increasingly complex structural forms. Leakage is a prominent problem, causing not only large-scale peeling of walls but also mold growth due to long-term dampness, leading to increased maintenance costs. Furthermore, steel corrosion shortens the building's lifespan, resulting in economic losses and significant resource waste, thus increasing the workload and difficulty of waterproofing projects. Currently, waterproofing of building exteriors often relies on material modification. Material waterproofing involves applying different waterproofing materials to form a unified waterproof layer on the water-facing or back-facing side of the building. Therefore, researching building waterproofing materials has become a crucial topic in building waterproofing engineering.

[0003] Existing building exterior wall waterproofing materials mostly use single organic or inorganic waterproofing materials. Organic waterproofing materials include high-molecular organic materials such as acrylates, polyurethanes, and urea-formaldehyde resins. However, these organic substances have problems such as brittle solids, poor impermeability, short service life, limited waterproofing stability, and easy environmental pollution. Inorganic materials are represented by cement. Cement materials have simple raw materials, low cost, are environmentally friendly and non-toxic, and have excellent durability. However, cement particles have a large particle size, making it difficult to penetrate into the fine cracks in the wall, and the waterproofing performance has not been significantly improved. Existing waterproofing materials lack hardness, especially for exterior walls, and are easily damaged and peel off after long-term use.

[0004] Chinese patent CN113582599A discloses a hybrid waterproofing material for construction, comprising 26.3% liquid and 73.7% powder. The powder is composed of 50% white cement, 49.35% quartz sand, 0.6% water-reducing agent, and 0.05% cellulose. While adding quartz sand effectively increases the material's hardness, its waterproofing performance remains unimproved, resulting in a short service life and significantly limiting its practical application. Therefore, this invention modifies the material by combining organic and inorganic materials. Soybean oil-based polyurethane prepolymer and epoxy resin are chain-extended with organosilicon fluorine to form an interpenetrating polymer network structure. This network is then combined with ultrafine cement containing various additives, integrating the flexibility of the polymer with the rigidity of the cement. This results in excellent waterproofing performance and is environmentally friendly. Summary of the Invention

[0005] The purpose of this invention is to solve the problems existing in the prior art and to provide a waterproof material for building exterior walls and its preparation method, so that the prepared building material has a significant waterproof effect, long service life and is green and environmentally friendly.

[0006] This invention is achieved through the following technical solution:

[0007] A waterproof material for building exterior walls comprises the following components in parts by weight: 100 parts ultrafine cement, 25-40 parts silica, 10-20 parts mineral admixtures, 12-15 parts bentonite, 3-15 parts environmentally friendly polyurethane / epoxy resin waterproofing agent, 3-8 parts polycarboxylate superplasticizer, 2-4 parts thickener, and 60-80 parts water.

[0008] The preparation method of environmentally friendly polyurethane / epoxy resin waterproofing agent is as follows:

[0009] Step (1): Add 100 parts by weight of epoxidized soybean oil acrylate to a reaction flask, stir and heat to 60-75℃, add 30-40 parts of isophorone diisocyanate dropwise under nitrogen protection, continue stirring for 2-5 hours, cool to room temperature, and obtain soybean oil-based polyurethane prepolymer.

[0010] Step (2): Stir 100 parts by weight of epoxy resin and 10-30 parts by weight of soybean oil-based polyurethane prepolymer at 50-65℃ for 20-40 minutes to obtain component A; add 8-12 parts of curing agent, 0.5-1.5 parts of curing accelerator, and 1-5 parts of the following structural formula... Mix the organosilicon fluorine chain extender, 2-4 parts of defoamer and 20-30 parts of acetone evenly to obtain component B; stir component A and component B at 75-90℃ for 5-10 minutes to allow natural defoaming, and obtain polyurethane / epoxy resin waterproofing agent.

[0011] Furthermore, the thickener is any one of sodium carboxymethyl cellulose, hydroxypropyl methylcellulose, or hydroxyethyl methylcellulose.

[0012] Furthermore, the preparation method of the mineral admixture is as follows: 100 parts by weight of blast furnace slag powder and 2000-3000 parts by weight of ethanol are added to a reaction flask, stirred evenly, and then 225-280 parts by weight of stearic acid are added. The mixture is reacted at 65-80℃ for 1-3 hours, cooled and filtered, washed with ethanol, and dried to obtain the mineral admixture.

[0013] Furthermore, in step (2), the curing agent is diethylenetriamine, the curing accelerator is 2,4,6-tris(dimethylaminomethyl)phenol, and the defoamer is silicone oil AK-158.

[0014] Furthermore, the preparation method of the organosilicon fluorine chain extender in step (2) is as follows:

[0015] Step S1: Under a nitrogen atmosphere, 1H,1H-perfluorooctane-1-ol and toluene were added to a reaction flask and stirred until homogeneous. Then, chloro(methyl)(phenyl)(vinyl)silane and triethylamine were added, and the mixture was stirred until the reaction was complete. After the reaction was finished, the mixture was cooled to room temperature and separated by column chromatography to obtain an alkenyl organosilicon fluorine monomer. The preparation reaction formula is as follows:

[0016]

[0017] Step S2: Under a nitrogen atmosphere, add the alkenyl organosilicon fluorine monomer and methanol to a reaction flask, stir until homogeneous, then add diethanolamine. React at 35-50℃ for 16-24 h, concentrate under reduced pressure, and separate by column chromatography to obtain the organosilicon fluorine chain extender. The preparation reaction formula is as follows:

[0018]

[0019] Furthermore, in step S1, the molar ratio of 1H,1H-perfluorooctane-1-ol, chloro(methyl)(phenyl)(vinyl)silane, and triethylamine is 1:(1.02-1.1):(1.3-1.5).

[0020] Furthermore, in step S1, the reaction temperature is 90-105℃ and the reaction time is 5-12h.

[0021] Furthermore, in step S2, the molar ratio of alkenyl organosilicon fluorine monomer and diethanolamine is 1:(1.1-1.2).

[0022] Further, weigh out ultrafine cement, silica, bentonite and water by weight, mix them and add them to the reactor; heat to 40-50℃, add environmentally friendly polyurethane / epoxy resin waterproofing agent and stir for 6-10 minutes; add mineral admixtures and polycarboxylate superplasticizer and continue stirring for 3-5 minutes; cool to 20-30℃, add thickener and continue stirring for 1-2 minutes, and then extrude it into rolls to obtain waterproof material for building exterior walls.

[0023] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0024] The epoxidized soybean oil acrylate molecule contains active hydroxyl groups and flexible fatty acid long-chain structures. The hydroxyl groups can react with isocyanate groups to generate soybean oil-based polyurethane prepolymers, which then react with the hydroxyl groups of epoxy resins to form an interpenetrating cross-linked network structure. The flexible long-chain structure can increase the dispersion effect in the system, enhance the interpenetration within the material, and improve the density between materials. The organosilicon in the organosilicone fluorine chain extender prevents water penetration by forming a dense silicon oxide protective film on the material surface. The organofluorine itself is hydrophobic and has good surface tension, which can prevent water from penetrating into the material, thereby improving the waterproof performance of building materials.

[0025] Because cement-based materials are porous, multiphase, heterogeneous, and brittle, environmentally friendly polyurethane / epoxy resin waterproofing agents can form polymer film structures in cement slurry, filling the pores between cement hydration products and improving the impermeability of the cement slurry. The benzene rings in its structure have good thermal stability. Therefore, the waterproofing material for building exterior walls of this invention has excellent mechanical properties, heat resistance, and waterproofing performance, creating a skin-like waterproof barrier for building materials. It uses environmentally friendly soybean derivatives, is environmentally friendly and biodegradable, has simple and readily available components, and low production costs, combining economic and environmental advantages, and has broad prospects for large-scale industrial application. Detailed Implementation

[0026] The present invention will now be described in detail with reference to specific embodiments. These embodiments will help those skilled in the art to further understand the present invention, but do not limit the invention in any way. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention. These all fall within the scope of protection of the present invention.

[0027] Unless otherwise stated, all raw materials and reagents used in this application are commercially available products or can be prepared by known methods.

[0028] Ultrafine cement: specific surface area 994 m² 2 / kg, with a volume average particle size of 25.9μm, Beijing Zhongde Xinya Building Technology Co., Ltd.

[0029] The preparation method of the mineral admixture is as follows: add 100 parts by weight of blast furnace slag powder and 2000-3000 parts by weight of ethanol to a reaction flask, stir evenly, add 225-280 parts by weight of stearic acid, react at 65-80℃ for 1-3 hours, cool and filter, wash with ethanol, and dry to obtain the mineral admixture.

[0030] Epoxidized soybean oil acrylate, average molecular weight 1200 g / mol, viscosity (25℃): 18000-32000 mPa·s, acid value: ≦10 mg KOH / g, Jiangsu Litian Technology Co., Ltd.

[0031] Epoxy resin, model WSR618(E-51), average molecular weight: 375 g / mol, viscosity (25℃): 1600 mPa·s, Jiangsu Nantong Xingchen Synthetic Materials Co., Ltd.

[0032] 1H,1H-perfluorooctane-1-ol, CAS number 307-30-2.

[0033] Chloro(methyl)(phenyl)(vinyl)silane, CAS number 17306-05-7.

[0034] Diethanolamine, CAS number 111-42-2.

[0035] Example 1

[0036] (1) Under a nitrogen atmosphere, 40 mmol of 1H,1H-perfluorooctane-1-ol and 480 mL of toluene were added to a reaction flask. After stirring evenly, 42 mmol of chloro(methyl)(phenyl)(vinyl)silane and 54 mmol of triethylamine were added. The reaction was carried out at 105 °C for 8 h. After cooling to room temperature, the alkenyl organosilicon fluorine monomer was obtained by column chromatography.

[0037] (2) Under a nitrogen atmosphere, 35 mmol of alkenyl organosilicon fluorine monomer and 560 mL of methanol were added to the reaction flask. After stirring evenly, 39.2 mmol of diethanolamine was added, and the reaction was carried out at 45 °C for 18 h. The mixture was concentrated under reduced pressure and separated by column chromatography to obtain organosilicon fluorine chain extender.

[0038] (3) Add 100g of epoxidized soybean oil acrylate to a reaction flask, stir and heat to 65°C, add 35g of isophorone diisocyanate dropwise under nitrogen protection, continue stirring for 4h, cool to room temperature, and obtain soybean oil-based polyurethane prepolymer.

[0039] (4) Stir 100g of epoxy resin and 10g of soybean oil-based polyurethane prepolymer at 55℃ for 30min to obtain component A; mix 10g of diethylenetriamine, 1g of 2,4,6-tris(dimethylaminomethyl)phenol, 1g of organosilicon fluorine chain extender, 2.5g of silicone oil AK-158 and 25g of acetone evenly to obtain component B; stir component A and component B at 85℃ for 8min and allow to defoam naturally to obtain polyurethane / epoxy resin waterproofing agent.

[0040] (5) Weigh 100g of ultrafine cement, 35g of silica, 13g of bentonite and 45g of water, mix them and add them to the reaction vessel; heat to 45℃, add 3g of environmentally friendly polyurethane / epoxy resin waterproofing agent and stir for 9min; add 12g of mineral admixture and 5g of polycarboxylate superplasticizer and continue stirring for 4min; cool to 25℃, add 3g of sodium carboxymethyl cellulose and continue stirring for 2min, and then extrude it into a roll to obtain waterproof material for building exterior walls.

[0041] Example 2

[0042] (1) Under a nitrogen atmosphere, 110 mmol of 1H,1H-perfluorooctane-1-ol and 880 mL of toluene were added to a reaction flask. After stirring evenly, 112.2 mmol of chloro(methyl)(phenyl)(vinyl)silane and 143 mmol of triethylamine were added. The reaction was carried out at 105 °C for 5 h. After cooling to room temperature, the alkenyl organosilicon fluorine monomer was obtained by column chromatography.

[0043] (2) Under a nitrogen atmosphere, 95 mmol of alkenyl organosilicon fluorine monomer and 950 mL of methanol were added to the reaction flask. After stirring evenly, 104.5 mmol of diethanolamine was added, and the reaction was carried out at 50 °C for 16 h. The mixture was concentrated under reduced pressure and separated by column chromatography to obtain organosilicon fluorine chain extender.

[0044] (3) Add 100g of epoxidized soybean oil acrylate to a reaction flask, stir and heat to 75°C, add 30g of isophorone diisocyanate dropwise under nitrogen protection, continue stirring for 2h, cool to room temperature, and obtain soybean oil-based polyurethane prepolymer.

[0045] (4) Stir 100g of epoxy resin and 15g of soybean oil-based polyurethane prepolymer at 60℃ for 35min to obtain component A; mix 10g of diethylenetriamine, 0.5g of 2,4,6-tris(dimethylaminomethyl)phenol, 2g of organosilicon fluorine chain extender, 2g of silicone oil AK-158 and 20g of acetone evenly to obtain component B; stir component A and component B at 90℃ for 5min and allow to defoam naturally to obtain polyurethane / epoxy resin waterproofing agent.

[0046] (5) Weigh 100g of ultrafine cement, 25g of silica, 12g of bentonite and 35g of water, mix them and add them to the reaction vessel; heat to 50℃, add 6g of environmentally friendly polyurethane / epoxy resin waterproofing agent and stir for 6min; add 10g of mineral admixture and 3g of polycarboxylate superplasticizer and continue stirring for 5min; cool to 30℃, add 2g of hydroxypropyl methylcellulose and continue stirring for 1min, and then extrude it into a roll to obtain waterproof material for building exterior walls.

[0047] Example 3

[0048] (1) Under a nitrogen atmosphere, 50 mmol of 1H,1H-perfluorooctane-1-ol and 750 mL of toluene were added to a reaction flask. After stirring evenly, 55 mmol of chloro(methyl)(phenyl)(vinyl)silane and 75 mmol of triethylamine were added. The reaction was carried out at 90 °C for 12 h. After cooling to room temperature, the mixture was separated by column chromatography to obtain alkenyl organosilicon fluorine monomers.

[0049] (2) Under a nitrogen atmosphere, 45 mmol of alkenyl organosilicon fluorine monomer and 900 mL of methanol were added to the reaction flask. After stirring evenly, 54 mmol of diethanolamine was added and the mixture was reacted at 35 °C for 24 h. The mixture was concentrated under reduced pressure and separated by column chromatography to obtain organosilicon fluorine chain extender.

[0050] (3) Add 100g of epoxidized soybean oil acrylate to a reaction flask, stir and heat to 60°C, add 30g of isophorone diisocyanate dropwise under nitrogen protection, continue stirring for 5h, cool to room temperature, and obtain soybean oil-based polyurethane prepolymer.

[0051] (4) Stir 100g of epoxy resin and 20g of soybean oil-based polyurethane prepolymer at 50℃ for 40min to obtain component A; mix 12g of diethylenetriamine, 1.5g of 2,4,6-tris(dimethylaminomethyl)phenol, 3g of organosilicon fluorine chain extender, 4g of silicone oil AK-158 and 30g of acetone evenly to obtain component B; stir component A and component B at 75℃ for 10min and allow to defoam naturally to obtain polyurethane / epoxy resin waterproofing agent.

[0052] (5) Weigh 100g of ultrafine cement, 40g of silica, 15g of bentonite and 50g of water, mix them and add them to the reactor; heat to 40℃, add 9g of environmentally friendly polyurethane / epoxy resin waterproofing agent and stir for 10min; add 20g of mineral admixture and 8g of polycarboxylate superplasticizer and continue stirring for 3min; cool to 30℃, add 4g of hydroxyethyl methyl cellulose and continue stirring for 2min, and then extrude it into a roll to obtain waterproof material for building exterior walls.

[0053] Example 4

[0054] (1) Under a nitrogen atmosphere, 15 mmol of 1H,1H-perfluorooctane-1-ol and 180 mL of toluene were added to a reaction flask. After stirring evenly, 16.2 mmol of chloro(methyl)(phenyl)(vinyl)silane and 21.3 mmol of triethylamine were added. The reaction was carried out at 100 °C for 9 h. After cooling to room temperature, the mixture was separated by column chromatography to obtain alkenyl organosilicon fluorine monomers.

[0055] (2) Under a nitrogen atmosphere, 12 mmol of alkenyl organosilicon fluorine monomer and 165 mL of methanol were added to the reaction flask. After stirring evenly, 13.68 mmol of diethanolamine was added, and the reaction was carried out at 45 °C for 20 h. The mixture was concentrated under reduced pressure and separated by column chromatography to obtain organosilicon fluorine chain extender.

[0056] (3) Add 100g of epoxidized soybean oil acrylate to a reaction flask, stir and heat to 70°C, add 32g of isophorone diisocyanate dropwise under nitrogen protection, continue stirring for 5h, cool to room temperature, and obtain soybean oil-based polyurethane prepolymer.

[0057] (4) Stir 100g of epoxy resin and 25g of soybean oil-based polyurethane prepolymer at 65℃ for 30min to obtain component A; mix 9g of diethylenetriamine, 0.8g of 2,4,6-tris(dimethylaminomethyl)phenol, 4g of organosilicon fluorine chain extender, 3.5g of silicone oil AK-158 and 24g of acetone evenly to obtain component B; stir component A and component B at 85℃ for 8min and allow to defoam naturally to obtain polyurethane / epoxy resin waterproofing agent.

[0058] (5) Weigh 100g of ultrafine cement, 30g of silica, 13g of bentonite and 45g of water, mix them and add them to the reactor; heat to 45℃, add 12g of environmentally friendly polyurethane / epoxy resin waterproofing agent and stir for 8min; add 16g of mineral admixture and 6g of polycarboxylate superplasticizer and continue stirring for 3min; cool to 30℃, add 3g of sodium carboxymethyl cellulose and continue stirring for 2min, and then extrude it into a roll to obtain waterproof material for building exterior walls.

[0059] Example 5

[0060] (1) Under a nitrogen atmosphere, 28 mmol of 1H,1H-perfluorooctane-1-ol and 350 mL of toluene were added to a reaction flask. After stirring evenly, 29.5 mmol of chloro(methyl)(phenyl)(vinyl)silane and 40.6 mmol of triethylamine were added. The reaction was carried out at 95 °C for 12 h. After cooling to room temperature, the mixture was separated by column chromatography to obtain alkenyl organosilicon fluorine monomers.

[0061] (2) Under a nitrogen atmosphere, 25 mmol of alkenyl organosilicon fluorine monomer and 350 mL of methanol were added to the reaction flask. After stirring evenly, 29 mmol of diethanolamine was added and reacted at 50 °C for 24 h. The mixture was concentrated under reduced pressure and separated by column chromatography to obtain organosilicon fluorine chain extender.

[0062] (3) Add 100g of epoxidized soybean oil acrylate to a reaction flask, stir and heat to 70°C, add 36g of isophorone diisocyanate dropwise under nitrogen protection, continue stirring for 5h, cool to room temperature, and obtain soybean oil-based polyurethane prepolymer.

[0063] (4) Stir 100g of epoxy resin and 30g of soybean oil-based polyurethane prepolymer at 65℃ for 40min to obtain component A; mix 11g of diethylenetriamine, 1.2g of 2,4,6-tris(dimethylaminomethyl)phenol, 5g of organosilicon fluorine chain extender, 3g of silicone oil AK-158 and 22g of acetone evenly to obtain component B; stir component A and component B at 85℃ for 9min and allow to defoam naturally to obtain polyurethane / epoxy resin waterproofing agent.

[0064] (5) Weigh 100g of ultrafine cement, 35g of silica, 15g of bentonite and 40g of water, mix them and add them to the reaction vessel; heat to 45℃, add 15g of environmentally friendly polyurethane / epoxy resin waterproofing agent and stir for 10min; add 16g of mineral admixture and 5g of polycarboxylate superplasticizer and continue stirring for 5min; cool to 30℃, add 3g of hydroxypropyl methylcellulose and continue stirring for 2min to obtain waterproofing material for building exterior walls.

[0065] Comparative Example 1

[0066] (1) 100g of epoxy resin and 10g of soybean oil-based polyurethane prepolymer (prepared in Example 1) were stirred at 55°C for 30min to obtain component A; 10g of diethylenetriamine, 1g of 2,4,6-tris(dimethylaminomethyl)phenol, 1g of diethanolamine, 2.5g of silicone oil AK-158 and 25g of acetone were mixed evenly to obtain component B; component A and component B were stirred at 85°C for 8min and allowed to defoam naturally to obtain polyurethane / epoxy resin material.

[0067] (2) Weigh 100g of ultrafine cement, 35g of silicon dioxide, 13g of bentonite and 45g of water, mix them and add them to the reactor; heat to 45℃, add 3g of environmentally friendly polyurethane / epoxy resin material and stir for 9min; add 12g of mineral admixture and 5g of polycarboxylate superplasticizer and continue stirring for 4min; cool to 25℃, add 3g of sodium carboxymethyl cellulose and continue stirring for 2min, and then extrude it into rolls to obtain building exterior wall material.

[0068] Comparative Example 2

[0069] Weigh 100g of ultrafine cement, 35g of silica, 13g of bentonite and 45g of water, mix them and add them to a reaction vessel; heat to 45℃ and stir for 9 minutes; add 12g of mineral admixture and 5g of polycarboxylate superplasticizer and continue stirring for 4 minutes; cool to 25℃, add 3g of sodium carboxymethyl cellulose and continue stirring for 2 minutes, then extrude and form into rolls to obtain building exterior wall material.

[0070] Water absorption performance test: The test was conducted in accordance with JGJ 70-2009 "Standard for Test Methods of Basic Performance of Building Mortar". The building materials prepared in Examples 1-5 and Comparative Examples 1-2 were made into specimens with a size of 70mm×70mm×70mm. They were left to stand at 20℃ for 24 hours, demolded, and then placed in a standard curing room at 20℃ and 95% relative humidity for 28 days. The specimens were then removed and dried at 80℃ for 48 hours. Their mass m0 was measured. The specimens were then immersed in a water tank with a water depth of 200mm for 48 hours. After that, they were removed, the surface water was wiped off with a wrung-out cloth, and their mass m1 was measured. The water absorption rate of mortar was calculated according to the formula (m1-m0) / m0. The test was performed three times on average, and the average value was taken.

[0071] Compressive strength test: Mechanical properties were tested according to the national standard GB / T 17671-1999 "Test Method for Strength of Cement Mortar (ISO Method)". The test specimens were mortar specimens with dimensions of 40mm×40mm×160mm. After curing at 20℃ and 60% relative humidity for 24 hours, the specimens were demolded and placed in standard water for 28 days before compressive strength testing. The compressive strength before immersion was recorded. Then, the specimens were immersed in a water tank with a water depth of 200mm for 48 hours and then removed to test the compressive strength after immersion. Six specimens were tested in parallel for each group, and the average value was taken.

[0072] Table 1 Waterproofing Performance Test

[0073]

[0074]

[0075] As shown in the test results above, the waterproof performance of building exterior wall materials gradually increases with the increase of the content of environmentally friendly polyurethane / epoxy resin waterproofing agent. The water absorption rate in Example 4 is only 3.82%, and the compressive strength before and after immersion is not significantly different. This is because, on the one hand, the epoxy soybean oil acrylate molecule contains active hydroxyl groups and flexible fatty acid long-chain structures. The hydroxyl groups can react with isocyanate groups to generate soybean oil-based polyurethane prepolymer, which then reacts with the hydroxyl groups of epoxy resin to form an interpenetrating cross-linked network structure. The flexible long-chain structure can increase the dispersion effect in the system, enhance the mutual penetration inside the material, and improve the density between materials. On the other hand, the organosilicon in the organosilicon fluorine chain extender prevents water penetration by forming a dense silicon oxide protective film on the material surface. The organofluorine itself is hydrophobic and has good surface tension, which can prevent water from penetrating into the material, thereby improving the waterproof performance of building materials.

[0076] Comparative Example 1 does not contain organosilicon fluorine chain extenders and cannot form a hydrophobic film on the material surface, but it contains an interpenetrating cross-linked network structure, so its waterproof performance is average; Comparative Example 2 does not contain environmentally friendly polyurethane / epoxy resin waterproofing agents, so water molecules can easily penetrate it and it does not have waterproof performance.

[0077] Permeability pressure resistance test: The test was conducted in accordance with JGJ 70-2009 "Standard for Test Methods of Basic Performance of Building Mortar". The building materials prepared in Examples 1-5 and Comparative Examples 1-2 were placed in the test mold to make a metal test mold with a size of 70mm×80mm×30mm. The test mold was placed in a standard curing room at 20℃ and 95% relative humidity for 28 days. Then, the mold was sealed with sealing material and placed in a mortar permeability tester for water permeability test. The test was stopped when water seepage was observed on the end face of 3 out of 6 test specimens. The permeability pressure value was recorded.

[0078] Heat resistance test: The test was conducted in accordance with GB / T 23440-2009 "Inorganic Waterproof and Leak-stopping Materials".

[0079] Table 2. Tests on impermeability and heat resistance.

[0080]

[0081]

[0082] Since cement-based materials are porous, multiphase, heterogeneous, and brittle, the addition of polyurethane / epoxy resin waterproofing agents can form a polymer film structure in the cement slurry, filling the pores between cement hydration products and improving the impermeability of the cement slurry. The benzene rings in its structure have good thermal stability. Therefore, the waterproofing material for building exterior walls of this invention has excellent mechanical properties, heat resistance, and waterproofing performance, creating a skin-like waterproof barrier for building materials. It uses environmentally friendly soybean derivatives, is environmentally friendly and biodegradable, has simple and readily available components, and low production costs, combining economic and environmental characteristics, and has broad prospects for large-scale industrial application.

[0083] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. For those skilled in the art, the present invention can be modified and varied in various ways. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principle of the present invention should be included within the scope of protection of the present invention.

Claims

1. A waterproof material for building exterior walls, characterized in that, The waterproof material comprises the following components in parts by weight: 100 parts ultrafine cement, 25-40 parts silica, 10-20 parts mineral admixtures, 12-15 parts bentonite, 3-15 parts environmentally friendly polyurethane / epoxy resin waterproofing agent, 3-8 parts polycarboxylate superplasticizer, 2-4 parts thickener and 60-80 parts water. The preparation method of the environmentally friendly polyurethane / epoxy resin waterproofing agent is as follows: Step (1): Add 100 parts by weight of epoxidized soybean oil acrylate to a reaction flask, stir and heat to 60-75℃, add 30-40 parts of isophorone diisocyanate dropwise under nitrogen protection, continue stirring for 2-5 hours, cool to room temperature, and obtain soybean oil-based polyurethane prepolymer. Step (2): Stir 100 parts by weight of epoxy resin and 10-30 parts by weight of soybean oil-based polyurethane prepolymer at 50-65℃ for 20-40 minutes to obtain component A; add 8-12 parts of curing agent, 0.5-1.5 parts of curing accelerator, and 1-5 parts of the following structural formula... Mix the organosilicon fluorine chain extender, 2-4 parts of defoamer and 20-30 parts of acetone evenly to obtain component B; stir component A and component B at 75-90℃ for 5-10 minutes and allow to defoam naturally to obtain polyurethane / epoxy resin waterproofing agent. The preparation method of the organosilicon fluorine chain extender in step (2) is as follows: Step S1: Under a nitrogen atmosphere, 1H,1H-perfluorooctane-1-ol and toluene were added to a reaction flask and stirred until homogeneous. Then, chloro(methyl)(phenyl)(vinyl)silane and triethylamine were added and stirred until the reaction was complete. After the reaction was completed, the mixture was cooled to room temperature and separated by column chromatography to obtain an alkenyl organosilicon fluorine monomer. Step S2: Under a nitrogen atmosphere, add alkenyl organosilicon fluorine monomer and methanol to a reaction flask, stir evenly, add diethanolamine, react at 35-50℃ for 16-24h, concentrate under reduced pressure, and separate by column chromatography to obtain organosilicon fluorine chain extender. In step S1, the molar ratio of 1H,1H-perfluorooctane-1-ol, chloro(methyl)(phenyl)(vinyl)silane, and triethylamine is 1:(1.02-1.1):(1.3-1.5). In step S2, the molar ratio of alkenyl organosilicon fluorine monomer and diethanolamine is 1:(1.1-1.2).

2. The waterproof material for building exterior walls according to claim 1, characterized in that, The thickener is any one of sodium carboxymethyl cellulose, hydroxypropyl methylcellulose, or hydroxyethyl methylcellulose.

3. The waterproof material for building exterior walls according to claim 1, characterized in that, The preparation method of the mineral admixture is as follows: 100 parts by weight of blast furnace slag powder and 2000-3000 parts by weight of ethanol are added to a reaction flask, stirred evenly, and then 225-280 parts by weight of stearic acid are added. The mixture is reacted at 65-80℃ for 1-3 hours, cooled and filtered, washed with ethanol, and dried to obtain the mineral admixture.

4. The waterproof material for building exterior walls according to claim 1, characterized in that, In step (2), the curing agent is diethylenetriamine, the curing accelerator is 2,4,6-tris(dimethylaminomethyl)phenol, and the defoamer is silicone oil AK-158.

5. The waterproof material for building exterior walls according to claim 1, characterized in that, In step S1, the reaction temperature is 90-105℃ and the reaction time is 5-12h.

6. A method for preparing a waterproof material for building exterior walls as described in any one of claims 1-5, characterized in that, Weigh out the ultrafine cement, silica, bentonite and water according to the weight parts, mix them and add them to the reaction vessel; heat to 40-50℃, add environmentally friendly polyurethane / epoxy resin waterproofing agent and stir for 6-10 minutes; add mineral admixtures and polycarboxylate superplasticizer and continue stirring for 3-5 minutes; cool to 20-30℃, add thickener and continue stirring for 1-2 minutes, and then extrude it into rolls to obtain waterproof material for building exterior walls.

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