Waterproof material for building external wall and preparation method of waterproof material

Abstract

The invention relates to the technical field of waterproof materials, and discloses a waterproof material for building exterior walls and a preparation method thereof.Epoxy soybean oil acrylate molecules contain active hydroxyl and a flexible fatty acid long-chain structure, and react with isocyanate groups and epoxy resin in sequence to form an interpenetrating cross-linked network structure; the dispersion effect in the system can be improved by the flexible long-chain structure, the interpenetration in the material is enhanced, and the density between the materials is improved; organic silicon in the organic silicon-fluorine chain extender forms a layer of compact silicon oxide protective film on the surface of a material to prevent water from permeating, and organic fluorine is hydrophobic, has good surface tension and can prevent water from permeating into the material, so that the waterproof performance of the building material is improved; the material prepared by the invention can be used for creating a skin type waterproof barrier for a building exterior wall material, has the characteristics of economy and environmental protection, and has a wide prospect of large-scale industrial application.

Description

Technical Field

[0001] The invention relates to the technical field of waterproof materials, in particular to a waterproof material for building exterior walls and a preparation method thereof. Background Art

[0002] At present, most buildings are high-rise buildings, and the building area is constantly increasing. The structural form of the building is becoming more and more complex. Leakage is a more prominent problem in buildings. It will not only cause large-scale peeling of the wall, but also make the wall moldy due to long-term leakage and moisture, resulting in increased maintenance costs during the use of the building; in addition, the rust of steel bars shortens the service life of the building, causing economic losses and serious waste of resources, etc., which increases the workload and difficulty of waterproofing projects accordingly; at present, the waterproofing of the exterior walls of buildings is mostly achieved through material modification to achieve the purpose of building waterproofing. Material waterproofing is to form an overall waterproof layer through construction of different waterproof materials, which is attached to the water-facing or water-retaining surface of the building to achieve the purpose of building waterproofing. Therefore, the study of building waterproof materials has become one of the important topics of building waterproofing projects.

[0003] Existing building exterior wall waterproofing materials are mostly processed with a single organic or inorganic waterproofing material. Organic waterproofing materials include polymer organic materials such as acrylates, polyurethanes, and urea-formaldehyde resins. However, these organic substances have the problems of brittle solid bodies, poor impermeability, short service life, limited waterproof stability, and easy to cause environmental pollution. Inorganic materials are represented by cement. Cement materials have simple raw materials, low cost, environmental protection, non-toxicity, and excellent durability. However, cement materials have large particle sizes and are difficult to inject into fine cracks on the wall, and the waterproofing performance has not been significantly improved. Existing waterproof materials are not hard enough, especially for exterior wall waterproofing, which is easily damaged and falls off after long-term use.

[0004] Chinese patent CN113582599A discloses a mixed waterproof material for construction, including 26.3% of liquid material and 73.7% of powder material, wherein the powder material is composed of 50% of white cement, 49.35% of quartz sand, 0.6% of water reducing agent and 0.05% of cellulose, and the hardness of the material can be effectively improved by adding quartz sand to the material, but its waterproof performance is still not improved, and its service life is short, which greatly limits its practical application; therefore, the present invention forms an interpenetrating polymer network structure by compounding and modifying organic materials and inorganic materials, and extending the soybean oil-based polyurethane prepolymer and epoxy resin with organic silicon fluorine, and combines it with ultrafine cement doped with various additives, so as to integrate the flexibility of the polymer with the rigidity of the cement, so that it has excellent performance in anti-seepage and waterproofing, and is green and environmentally friendly. Summary of the invention

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

[0006] The present invention is achieved through the following technical solutions:

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

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

[0009] Step (1), adding 100 parts by weight of epoxy soybean oil acrylate into a reaction flask, stirring and heating to 60-75° C., adding 30-40 parts of isophorone diisocyanate dropwise under nitrogen protection, continuing stirring for 2-5 hours, and cooling to room temperature to obtain a soybean oil-based polyurethane prepolymer.

[0010] Step (2), stirring 100 parts by weight of epoxy resin and 10-30 parts of soybean oil-based polyurethane prepolymer at 50-65° C. for 20-40 minutes to obtain component A; adding 8-12 parts of curing agent, 0.5-1.5 parts of curing accelerator, 1-5 parts of structural formula The organic silicon fluorine chain extender, 2-4 parts of defoaming agent and 20-30 parts of acetone are evenly mixed to obtain component B; component A and component B are stirred at 75-90° C. for 5-10 minutes, and naturally defoamed to obtain a polyurethane / epoxy resin waterproofing agent.

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

[0012] Furthermore, the preparation method of the mineral admixture is: add 100 parts of blast furnace slag powder and 2000-3000 parts of ethanol by weight into a reaction flask, stir evenly, add 225-280 parts of stearic acid, react at 65-80°C for 1-3h, cool and filter, wash with ethanol, and obtain the mineral admixture after drying.

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

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

[0015] Step S1: In a nitrogen atmosphere, add 1H,1H-perfluorooctane-1-ol and toluene to a reaction flask, stir evenly, then add chloro(methyl)(phenyl)(vinyl)silane and triethylamine, stir to react, and after the reaction is completed, cool to room temperature, separate by column chromatography, and obtain an alkenyl organosilicone fluorine monomer. The preparation reaction formula is as follows:

[0016]

[0017] Step S2: Add alkenyl organosilicon fluorine monomer and methanol to a reaction flask under nitrogen atmosphere, stir evenly, add diethanolamine, react at 35-50° C. for 16-24 hours, concentrate under reduced pressure, separate by column chromatography, and obtain an 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° C., and the reaction time is 5-12 h.

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

[0022] Furthermore, ultrafine cement, silicon dioxide, bentonite and water are weighed by weight, mixed and added into a reaction kettle; the temperature is raised to 40-50° C., an environmentally friendly polyurethane / epoxy resin waterproofing agent is added and stirred for 6-10 minutes; mineral admixtures and polycarboxylic acid water reducer are added and stirred for 3-5 minutes; the temperature is lowered to 20-30° C., a thickener is added and stirred for 1-2 minutes, and then extruded into a coil to obtain a waterproof material for building exterior walls.

[0023] Compared with the prior art, the present invention has the following beneficial effects:

[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 interpenetrating cross-linked network structures. The flexible long-chain structure can increase the dispersion effect in the system, enhance the mutual penetration within the material, and improve the density between materials. The silicone in the silicone fluorine chain extender prevents moisture penetration by forming a dense silicon oxide protective film on the surface of the material. The organic fluorine itself is hydrophobic and has good surface tension, which can prevent moisture from penetrating into the material, thereby improving the waterproof performance of building materials.

[0025] Since cement materials are porous, multi-phase, inhomogeneous and brittle materials, the environmentally friendly polyurethane / epoxy resin waterproofing agent can form a polymer membrane structure in the cement slurry, fill the pores between the cement hydration products, and improve the anti-seepage performance of the cement slurry. The benzene ring in its structure has good thermal stability. Therefore, the waterproof material for building exterior walls of the present invention has excellent mechanical properties, heat resistance and waterproof properties, and can create a skin-like waterproof barrier for building materials. It uses environmentally friendly soybean derivatives, is environmentally friendly and biodegradable, has simple and easy-to-obtain components, and has low production costs. It has both economic and environmental protection characteristics and has broad prospects for large-scale industrial applications. DETAILED DESCRIPTION

[0026] The present invention is described in detail below in conjunction with specific embodiments. The following embodiments will help those skilled in the art to further understand the present invention, but are not intended to limit the present invention in any form. It should be noted that, for those of ordinary skill in the art, several variations and improvements may be made without departing from the concept of the present invention. These all belong to the protection scope of the present invention.

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

[0028] Ultrafine cement: specific surface area 994m 2 / kg, volume average particle size is 25.9μm, Beijing Sino-German Xinya Building Technology Co., Ltd.

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

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

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

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

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

[0034] Diethanolamine, CAS number is 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, and after stirring, 42 mmol of chloro(methyl)(phenyl)(vinyl)silane and 54 mmol of triethylamine were added, and the mixture was reacted at 105° C. for 8 h. The mixture was cooled to room temperature and separated by column chromatography to obtain an alkenyl organosilicone fluorine monomer.

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

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

[0039] (4) 100 g of epoxy resin and 10 g of soybean oil-based polyurethane prepolymer were stirred at 55° C. for 30 min to obtain component A; 10 g of diethylenetriamine, 1 g of 2,4,6-tris(dimethylaminomethyl)phenol, 1 g of organic silicone fluorine chain extender, 2.5 g of silicone oil AK-158 and 25 g of acetone were mixed evenly to obtain component B; components A and B were stirred at 85° C. for 8 min, and naturally defoamed to obtain a polyurethane / epoxy resin waterproofing agent.

[0040] (5) Weigh 100 g of ultrafine cement, 35 g of silicon dioxide, 13 g of bentonite and 45 g of water, mix and add to a reactor; heat to 45° C., add 3 g of environmentally friendly polyurethane / epoxy resin waterproofing agent and stir for 9 min; add 12 g of mineral admixture and 5 g of polycarboxylic acid water reducer and continue stirring for 4 min; cool to 25° C., add 3 g of sodium carboxymethyl cellulose and continue stirring for 2 min, and then extrude and mold into a roll to obtain a 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, and after stirring, 112.2 mmol of chloro(methyl)(phenyl)(vinyl)silane and 143 mmol of triethylamine were added, and the mixture was reacted at 105° C. for 5 h. The mixture was cooled to room temperature and separated by column chromatography to obtain an alkenyl organosilicone fluorine monomer.

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

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

[0045] (4) 100 g of epoxy resin and 15 g of soybean oil-based polyurethane prepolymer were stirred at 60° C. for 35 min to obtain component A; 10 g of diethylenetriamine, 0.5 g of 2,4,6-tris(dimethylaminomethyl)phenol, 2 g of organic silicone fluorine chain extender, 2 g of silicone oil AK-158 and 20 g of acetone were mixed evenly to obtain component B; components A and B were stirred at 90° C. for 5 min, and naturally defoamed to obtain a polyurethane / epoxy resin waterproofing agent.

[0046] (5) Weigh 100 g of ultrafine cement, 25 g of silicon dioxide, 12 g of bentonite and 35 g of water, mix and add to a reactor; heat to 50° C., add 6 g of environmentally friendly polyurethane / epoxy resin waterproofing agent and stir for 6 min; add 10 g of mineral admixture and 3 g of polycarboxylic acid water reducer and continue stirring for 5 min; cool to 30° C., add 2 g of hydroxypropyl methylcellulose and continue stirring for 1 min, and then extrude and mold into a roll to obtain a 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, and after stirring, 55 mmol of chloro(methyl)(phenyl)(vinyl)silane and 75 mmol of triethylamine were added, and the mixture was reacted at 90° C. for 12 h. The mixture was cooled to room temperature and separated by column chromatography to obtain an alkenyl organosilicone fluorine monomer.

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

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

[0051] (4) 100 g of epoxy resin and 20 g of soybean oil-based polyurethane prepolymer were stirred at 50° C. for 40 min to obtain component A; 12 g of diethylenetriamine, 1.5 g of 2,4,6-tris(dimethylaminomethyl)phenol, 3 g of organic silicone fluorine chain extender, 4 g of silicone oil AK-158 and 30 g of acetone were mixed evenly to obtain component B; components A and B were stirred at 75° C. for 10 min, and naturally defoamed to obtain a polyurethane / epoxy resin waterproofing agent.

[0052] (5) Weigh 100 g of ultrafine cement, 40 g of silicon dioxide, 15 g of bentonite and 50 g of water, mix and add to a reactor; heat to 40° C., add 9 g of environmentally friendly polyurethane / epoxy resin waterproofing agent and stir for 10 min; add 20 g of mineral admixture and 8 g of polycarboxylic acid water reducer and continue stirring for 3 min; cool to 30° C., add 4 g of hydroxyethyl methyl cellulose and continue stirring for 2 min, and then extrude and mold into a roll to obtain a 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, and after stirring, 16.2 mmol of chloro(methyl)(phenyl)(vinyl)silane and 21.3 mmol of triethylamine were added, and the mixture was reacted at 100° C. for 9 h. The mixture was cooled to room temperature, and separated by column chromatography to obtain an alkenyl organosilicone fluorine monomer.

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

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

[0057] (4) 100 g of epoxy resin and 25 g of soybean oil-based polyurethane prepolymer were stirred at 65° C. for 30 min to obtain component A; 9 g of diethylenetriamine, 0.8 g of 2,4,6-tris(dimethylaminomethyl)phenol, 4 g of organic silicone fluorine chain extender, 3.5 g of silicone oil AK-158 and 24 g of acetone were mixed evenly to obtain component B; components A and B were stirred at 85° C. for 8 min, and naturally defoamed to obtain a polyurethane / epoxy resin waterproofing agent.

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

[0059] Example 5

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

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

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

[0063] (4) 100 g of epoxy resin and 30 g of soybean oil-based polyurethane prepolymer were stirred at 65° C. for 40 min to obtain component A; 11 g of diethylenetriamine, 1.2 g of 2,4,6-tris(dimethylaminomethyl)phenol, 5 g of organic silicone fluorine chain extender, 3 g of silicone oil AK-158 and 22 g of acetone were mixed evenly to obtain component B; components A and B were stirred at 85° C. for 9 min, and naturally defoamed to obtain a polyurethane / epoxy resin waterproofing agent.

[0064] (5) Weigh 100 g of ultrafine cement, 35 g of silicon dioxide, 15 g of bentonite and 40 g of water, mix and add to a reactor; heat to 45° C., add 15 g of environmentally friendly polyurethane / epoxy resin waterproofing agent and stir for 10 min; add 16 g of mineral admixture and 5 g of polycarboxylic acid water reducer and continue stirring for 5 min; cool to 30° C., add 3 g of hydroxypropyl methylcellulose and continue stirring for 2 min to obtain a waterproof material for building exterior walls.

[0065] Comparative Example 1

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

[0067] (2) Weigh 100 g of ultrafine cement, 35 g of silicon dioxide, 13 g of bentonite and 45 g of water, mix and add to a reactor; heat to 45° C., add 3 g of environmentally friendly polyurethane / epoxy resin material and stir for 9 min; add 12 g of mineral admixture and 5 g of polycarboxylic acid water reducer and continue stirring for 4 min; cool to 25° C., add 3 g of sodium carboxymethyl cellulose and continue stirring for 2 min, and then extrude and mold into a coil to obtain a building exterior wall material.

[0068] Comparative Example 2

[0069] Weigh 100g of ultrafine cement, 35g of silicon dioxide, 13g of bentonite and 45g of water, mix and add to a reactor; heat to 45°C and stir for 9min; add 12g of mineral admixture and 5g of polycarboxylate water reducer and continue stirring for 4min; cool to 25°C, add 3g of sodium carboxymethyl cellulose and continue stirring for 2min, then extrude and form into a coil to obtain a building exterior wall material.

[0070] Water absorption performance test: refer to JGJ 70-2009 "Standard for Test Methods for Basic Performance of Building Mortar" for testing. The building materials prepared in Examples 1-5 and Comparative Examples 1-2 are made into test pieces with a size of 70 mm × 70 mm × 70 mm, left to stand at 20°C for 24 h, demolded, and then placed in a standard curing room at 20°C and a relative humidity of 95% for curing for 28 d. The test piece is taken out and dried at 80°C for 48 h. Its mass is m0. The test piece is immersed in a water tank with a height of 200 mm in water. After 48 h, it is taken out and the surface water is wiped off with a wrung-out cloth. Its mass is m1. According to the formula for mortar water absorption = (m1-m0) / m0, the test is performed 3 times on average and the average value is taken.

[0071] Compressive strength test: Mechanical properties test was carried out with reference to national GB / T 17671-1999 "Test method for strength of cement mortar (ISO method)". The test specimen size was 40mm×40mm×160mm mortar specimen. The specimen was cured at 20℃ and relative humidity of 60% for 24h before demoulding. The compressive strength was tested in standard water for 28d, which was recorded as the compressive strength before immersion. The specimen was then immersed in a water tank with a height of 200mm and taken out after 48h to test the compressive strength after immersion. Six specimens were tested in parallel in each group and the average value was taken.

[0072] Table 1 Waterproof performance test

[0073]

[0074]

[0075] It can be seen from the test results in the above table that with the increase of the content of environmentally friendly polyurethane / epoxy resin waterproofing agent, the waterproof performance of the building exterior wall material is gradually enhanced. The water absorption rate in Example 4 is only 3.82%, and the compressive strength before and after immersion does not change much. 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 group can react with the isocyanate group to form a soybean oil-based polyurethane prepolymer, and then react with the hydroxyl group of the 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 the 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 surface of the material. The organic fluorine 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.

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

[0077] Test of anti-seepage pressure performance: refer to JGJ 70-2009 "Standard for Test Methods for Basic Performance of Building Mortar", put the building materials prepared in Examples 1-5 and Comparative Examples 1-2 into a test mold, make a metal test mold with a size of 70mm×80mm×30mm, place it in a standard curing room at 20°C and a relative humidity of 95% for curing for 28 days, and then seal it with a sealing material and put it into a mortar permeameter for a water permeability test. When water seepage occurs on the end faces of 3 of the 6 test pieces, the test is stopped and the anti-seepage pressure value is recorded.

[0078] Heat resistance test: Tested in accordance with GB / T 23440-2009 "Inorganic waterproof and leak-proof materials".

[0079] Table 2 Impermeability and heat resistance test

[0080]

[0081]

[0082] Since cement materials are porous, multi-phase, inhomogeneous and brittle materials, the addition of polyurethane / epoxy resin waterproofing agent can form a polymer membrane structure in the cement paste, fill the pores between cement hydration products, and improve the anti-seepage performance of the cement paste. The benzene ring in its structure has good thermal stability. Therefore, the waterproof material for building exterior walls of the present invention has excellent mechanical properties, heat resistance and waterproof properties, and can create a skin-like waterproof barrier for building materials. It uses environmentally friendly soybean derivatives, is environmentally friendly and biodegradable, has simple and easy-to-obtain components, has low production costs, and has both economic and environmental protection characteristics, and has broad prospects for large-scale industrial applications.

[0083] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope 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 of ultrafine cement, 25-40 parts of silicon dioxide, 10-20 parts of mineral admixture, 12-15 parts of bentonite, 3-15 parts of environmentally friendly polyurethane / epoxy resin waterproofing agent, 3-8 parts of polycarboxylate water reducer, 2-4 parts of thickener and 60-80 parts of water; The preparation method of the environmentally friendly polyurethane / epoxy resin waterproofing agent is: Step (1), adding 100 parts by weight of epoxy soybean oil acrylate into a reaction flask, stirring and heating to 60-75° C., adding 30-40 parts of isophorone diisocyanate dropwise under nitrogen protection, continuing stirring for 2-5 hours, and cooling to room temperature to obtain a soybean oil-based polyurethane prepolymer; Step (2), stirring 100 parts by weight of epoxy resin and 10-30 parts of soybean oil-based polyurethane prepolymer at 50-65° C. for 20-40 minutes to obtain component A; adding 8-12 parts of curing agent, 0.5-1.5 parts of curing accelerator, 1-5 parts of structural formula The organic silicon fluorine chain extender, 2-4 parts of defoaming agent and 20-30 parts of acetone are evenly mixed to obtain component B; component A and component B are stirred at 75-90° C. for 5-10 minutes, and naturally defoamed to obtain a polyurethane / epoxy resin waterproofing agent.

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 methyl cellulose or hydroxyethyl methyl cellulose.

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: add 100 parts of blast furnace slag powder and 2000-3000 parts of ethanol by weight into a reaction flask, stir evenly, add 225-280 parts of stearic acid, react at 65-80° C. for 1-3 hours, cool and filter, wash with ethanol, and dry to obtain the mineral admixture.

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

5. The waterproof material for building exterior walls according to claim 1, characterized in that: The preparation method of the organic silicon fluorine chain extender in step (2) is: Step S1, under a nitrogen atmosphere, add 1H,1H-perfluorooctane-1-ol and toluene to a reaction flask, stir evenly, add chloro(methyl)(phenyl)(vinyl)silane and triethylamine, stir to react, and after the reaction is completed, cool to room temperature, separate by column chromatography, and obtain an alkenyl organosilicone 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° C. for 16-24 hours, concentrate under reduced pressure, separate by column chromatography, and obtain an organosilicon fluorine chain extender.

6. The waterproof material for building exterior walls according to claim 5, characterized in that: In the 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).

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

8. The waterproof material for building exterior walls according to claim 5, characterized in that: In the step S2, the molar ratio of the alkenyl organosilicone fluorine monomer to diethanolamine is 1:(1.1-1.2).

9. A method for preparing a waterproof material for building exterior walls according to any one of claims 1 to 8, characterized in that: Ultrafine cement, silicon dioxide, bentonite and water are weighed by weight, mixed and added into a reaction kettle; the temperature is raised to 40-50° C., and an environmentally friendly polyurethane / epoxy resin waterproofing agent is added and stirred for 6-10 minutes; mineral admixtures and polycarboxylic acid water reducer are added and stirred for 3-5 minutes; the temperature is lowered to 20-30° C., a thickener is added and stirred for 1-2 minutes, and then extruded into a coiled material to obtain a waterproof material for building exterior walls.

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