Modified epoxy resin water permeable brick and preparation method thereof

Abstract

The invention provides a modified epoxy resin water permeable brick and a preparation method thereof. The modified epoxy resin water permeable brick is prepared from the following raw materials in parts by weight: 95 to 105 parts of aggregate, 8 to 15 parts of modified epoxy resin, 1 to 3 parts of curing agent, 5 to 8 parts of composite filler, 0.1 to 0.3 part of exciting agent, 2 to 4 parts of self-repairing component and 1 to 3 parts of diluent. According to the water permeable brick, through the synergistic effect of the organic silicon modified epoxy resin and the special curing agent, the anti-aging performance of the material is improved. The introduced Si-O-Si bond can effectively resist the attack of ultraviolet photons; long-chain alkyl in the curing agent forms a compact physical barrier layer, so that oxygen and moisture permeation is greatly slowed down, the water permeable brick can effectively resist pulverization, yellowing and embrittlement in long-term outdoor use, the compressive strength and the water permeability coefficient of the water permeable brick can still keep an extremely high retention rate after long-term use, the service life is remarkably prolonged, and the water permeable brick is suitable for popularization and application. The industrial pain point that a traditional resin-based water permeable brick is easy to age is solved.

Description

Technical Field

[0001] This invention relates to the field of building materials technology, specifically to a modified epoxy resin permeable brick and its preparation method. Background Technology

[0002] Epoxy resin permeable bricks, as a new type of environmentally friendly building material, are widely used in the field of urban permeable paving due to their excellent physical and chemical properties. These permeable bricks use epoxy resin as a binder, which binds the aggregate through its excellent adhesion and film-forming properties. They possess advantages such as high strength, good wear resistance, stable permeability, and excellent compressive strength, while also exhibiting good resistance to acid and alkali corrosion, making them suitable for complex environments such as plazas and parking lots. However, existing epoxy resin permeable bricks have revealed a key technical bottleneck during long-term outdoor use—insufficient anti-aging performance. Under the combined effects of continuous solar ultraviolet radiation, temperature cycling, oxygen, and moisture, the epoxy resin polymer chains undergo photo-oxidative aging and thermo-oxidative aging. This aging phenomenon brings a series of serious negative impacts to the permeable bricks: First, it causes the resin itself to gradually yellow and powder, not only affecting the aesthetics of the landscape but also damaging the bonding interface between the resin and the aggregate, causing the aggregate to loosen or even fall off, thus compromising the structural integrity of the brick. Second, aging causes the resin cross-linking network to degrade, making the material brittle and significantly reducing its toughness. This weakens the brick's impact resistance and load-bearing capacity, making it more prone to cracking and breakage under vehicle or pedestrian loads. Summary of the Invention

[0003] In view of this, the present invention proposes a modified epoxy resin permeable brick and its preparation method to solve the above problems.

[0004] The technical solution of this invention is implemented as follows:

[0005] A modified epoxy resin permeable brick comprises the following raw materials in parts by weight: 95-105 parts aggregate, 8-15 parts modified epoxy resin, 1-3 parts curing agent, 5-8 parts composite filler, 0.1-0.3 parts activator, 2-4 parts self-healing component, and 1-3 parts diluent.

[0006] Furthermore, the modified epoxy resin is prepared by the following method:

[0007] A1. Hydrogenated bisphenol A type epoxy resin is mixed with epoxy-terminated polydimethylsiloxane, nitrogen gas is introduced, triphenylphosphine is added, and the mixture is stirred at 90-110℃ for 2-4 hours to obtain epoxy-organosilicon block prepolymer.

[0008] A2. Cool the epoxy-organosilicon block prepolymer to 60-70℃, and add polyetheramine dropwise over 30-45 minutes under a nitrogen atmosphere. After the addition is complete, continue stirring and reacting for 1-2 hours to obtain the modified epoxy resin.

[0009] Furthermore, in A1, the mass ratio of hydrogenated bisphenol A type epoxy resin, terminal epoxy polydimethylsiloxane, and triphenylphosphine is (90-110):(6-12):(0.3-0.5), the nitrogen flow rate is 50-100 mL / min, and the stirring speed is 200-400 rpm; in A2, the amount of polyetheramine added is 8-15% of the mass of the epoxy-organosilicon block prepolymer, and the stirring speed is 200-400 rpm.

[0010] Furthermore, the aggregate is quartz sand with a particle size of 2-5mm.

[0011] Furthermore, the curing agent is prepared by the following method: polyoxypropylene diamine and C12-14 alkyl glycidyl ether are mixed at a mass ratio of 100:(10-20) under a nitrogen atmosphere to obtain mixture ①. 0.2-0.4% of triphenylphosphine by mass of mixture ① is added, and the mixture is stirred at 200-400 rpm at 80-90℃ for 1.5-2.5 h. After the reaction is completed, the mixture is cooled to room temperature to obtain the curing agent.

[0012] Furthermore, the composite filler is composed of mineral powder, fly ash, and red mud in a mass ratio of (3-5):(3-5):(2-4).

[0013] Furthermore, the activator is composed of sodium silicate, silane coupling agent KH-560, and nano silica slurry in a mass ratio of (14-17):(2-4):(1-3).

[0014] Furthermore, the self-healing component is prepared by the following method:

[0015] B1. Sodium tungstate and hydrogen peroxide urea are mixed at a mass ratio of 2.8-3.2:2 to obtain mixture ②. 2.5-3.5 times the mass of deionized water of mixture ② are added and stirred to dissolve, thus obtaining a solution. The solution is placed in a freezer at -40 to -35°C for 4-6 hours and then transferred to a freeze dryer. Primary drying is carried out at 10-30 Pa and a partition temperature of -30 to -20°C for 20-28 hours. Then, the partition temperature is raised to 25-30°C and secondary drying is carried out for 4-6 hours to obtain a solid block. The solid block is crushed and sieved to obtain powder with a particle size of 10-50 μm. The powder is coated with molten stearic acid in a fluidized bed at 65-70°C. After coating, it is sieved again to obtain powder with a particle size of 20-60 μm, thus obtaining sodium tungstate-hydrogen peroxide urea composite powder.

[0016] B2. Prepare 3-4% aqueous solutions of gelatin and gum arabic to obtain gelatin solution and gum arabic solution respectively, and adjust the pH to 7.5-8.0; add phenylhydrazine to gelatin solution, then add gum arabic solution, adjust pH to 4.0-4.5, stir evenly, cool to 5-10℃ and solidify for 1.5-2h, add glutaraldehyde and react for 2-3h, then filter out solids, wash with deionized water 2-3 times, and then dry at -0.08~-0.10MPa and 40~50℃ to constant weight to obtain phenylhydrazine microcapsules;

[0017] B3. Add neopentyl glycol diglycidyl ether and hydrogenated castor oil to the reactor. Stir at 200-300 rpm for 20-30 min under a nitrogen atmosphere. Add urea-formaldehyde resin microcapsules, sodium tungstate-hydrogen peroxide urea composite powder, and phenylhydrazine microcapsules at 30-35℃. Increase the stirring speed to 500-600 rpm and stir for 40-60 min. Then reduce the stirring speed to 100-150 rpm and mature for 1-2 h. Then degas at -0.07 to -0.09 MPa for 10-20 min and cool to 20-25℃ to obtain the self-healing component.

[0018] Furthermore, in B2, the mass ratio of phenylhydrazine, gelatin solution, arabinogalactone, and glutaraldehyde is 1:(30-40):(30-40):(0.15-0.25); in B3, the mass ratio of glycol diglycidyl ether, hydrogenated castor oil, urea-formaldehyde resin microcapsules, sodium tungstate-hydrogen peroxide urea composite powder, and phenylhydrazine microcapsules is (35-40):(3-5):(45-50):(8-12):(10-15), and the nitrogen gas rate is 45-55 mL / min.

[0019] Furthermore, the urea-formaldehyde resin microcapsules are prepared by the following method:

[0020] C1. Add urea, formaldehyde solution with a concentration of 35-40wt%, and deionized water to the reaction vessel. Add triethanolamine to adjust the pH to 8.0-8.5. Stir the mixture at 200-300rpm for 60-90 minutes at 70-75℃ to obtain a urea-formaldehyde resin prepolymer solution.

[0021] C2. Cool the urea-formaldehyde resin prepolymer solution to 40-45℃, add sodium dodecyl sulfate, gum arabic, and deionized water, and stir until completely dissolved. Slowly add dicyclopentadiene and vinylbenzene, and emulsify at 5000-8000 rpm for 10-15 minutes.

[0022] C3. After emulsification, slowly adjust the pH of the emulsion to 2.5-3.5 with citric acid or hydrochloric acid solution, slowly raise the temperature to 55-60℃ at a rate of 1-2℃ / min, and stir the reaction at 300-400 rpm for 2-3 hours. Then add ammonium chloride and continue stirring for 1-2 hours. After the reaction is complete, vacuum filter the solid microcapsules, wash them 2-4 times alternately with deionized water and anhydrous ethanol, and then vacuum dry them to constant weight at 40-45℃ and -0.08 to -0.10 MPa. Sieve the microcapsules with a particle size of 50-100 μm to obtain urea-formaldehyde resin microcapsules.

[0023] Furthermore, in C1, the mass ratio of urea, formaldehyde solution, and deionized water is 1:(2.5-3.5):(4-6), and in C2, the mass ratio of urea-formaldehyde resin prepolymer solution, sodium dodecyl sulfate, gum arabic, deionized water, dicyclopentadiene, and vinylbenzene is (50-70):(0.5-1.0):(1.0-2.0):(120-180):(30-40):(2-5).

[0024] Furthermore, the diluent is composed of neopentyl glycol diglycidyl ether, C12-14 alkyl glycidyl ether, BYK-A530 defoamer, and BYK-2155 wetting and dispersing agent in a mass ratio of (70-80):(20-30):(0.5-1.0):(1-2).

[0025] Furthermore, a method for preparing modified epoxy resin permeable bricks includes the following steps:

[0026] S1. Dry the aggregate at 100-110℃ to constant weight, add composite filler to the aggregate, and stir at 100-200 rpm for 3-5 min; then add activator, modified epoxy resin, self-healing component and diluent, and stir at 400-600 rpm for 5-8 min; finally add curing agent and stir at 600-800 rpm for 1-2 min to obtain mixture.

[0027] S2. Transfer the mixture into the mold and press it at 10-15MPa pressure at room temperature for 30-60s.

[0028] S3. After demolding, place the brick blank on a curing rack and cure it for 24-48 hours at 25-35℃ and 40-60% relative humidity. Then, continue curing it for 7-10 days at 20-30℃ and 40-70% relative humidity to obtain modified epoxy resin permeable brick.

[0029] Compared with the prior art, the beneficial effects of the present invention are:

[0030] 1. The permeable brick of this invention achieves improved anti-aging performance through the synergistic effect of organosilicon-modified epoxy resin and a special curing agent. The introduced Si-O-Si bonds effectively resist the attack of ultraviolet photons; while the long-chain alkyl groups in the curing agent form a dense physical barrier layer, greatly slowing down the penetration of oxygen and moisture. This allows the permeable brick to effectively resist powdering, yellowing, and embrittlement during long-term outdoor use. Its compressive strength and permeability coefficient can still maintain a very high retention rate after long-term use, significantly extending its service life and solving the industry pain point of easy aging of traditional resin-based permeable bricks.

[0031] 2. The self-healing agent of this invention, when microcracks appear in the brick due to external stress or aging, causes the microcapsules in the system to rupture. Through a highly efficient sodium tungstate-phenylhydrazine redox catalytic reaction, the repair monomers rapidly polymerize, automatically healing the cracks. This mechanism can promptly restore the mechanical properties and structural integrity of the material, actively breaking the vicious cycle of "microcracks → accelerated performance degradation," thereby extending the service life of the product and significantly reducing maintenance costs and frequency.

[0032] 3. The composite filler and activator of this invention construct a robust "organic-inorganic hybrid network" between the resin and aggregate, enhancing interfacial adhesion and thus building a solid mechanical framework while maintaining a large number of interconnected pores. Therefore, this permeable brick simultaneously possesses high compressive and flexural strength as well as a high permeability coefficient. Detailed Implementation

[0033] To better understand the technical content of this invention, specific embodiments are provided below to further illustrate the invention.

[0034] Unless otherwise specified, the experimental methods used in the embodiments of this invention are all conventional methods.

[0035] Unless otherwise specified, all materials and reagents used in the embodiments of this invention are commercially available.

[0036] Example 1

[0037] A modified epoxy resin permeable brick comprises the following raw materials in parts by weight: 95 parts aggregate, 8 parts modified epoxy resin, 1 part curing agent, 5 parts composite filler, 0.1 parts activator, 2 parts self-healing component, and 1 part diluent. The aggregate is quartz sand with a particle size of 2 mm. The composite filler consists of mineral powder, fly ash, and red mud in a mass ratio of 3:3:2. The activator consists of sodium silicate, silane coupling agent KH-560, and nano-silica slurry in a mass ratio of 14:2:1. The diluent consists of neopentyl glycol diglycidyl ether, C12-14 alkyl glycidyl ether, BYK-A530 defoamer, and BYK-2155 wetting and dispersing agent in a mass ratio of 70:20:0.5:1.

[0038] The modified epoxy resin is prepared by the following method:

[0039] A1. Hydrogenated bisphenol A type epoxy resin was mixed with epoxy-terminated polydimethylsiloxane, nitrogen gas was introduced, triphenylphosphine was added, and the mixture was stirred at 90°C for 4 hours to obtain an epoxy-organosilicon block prepolymer. The mass ratio of hydrogenated bisphenol A type epoxy resin, epoxy-terminated polydimethylsiloxane, and triphenylphosphine was 90:6:0.3, the nitrogen flow rate was 50 mL / min, and the stirring speed was 200 rpm.

[0040] A2. The epoxy-silicone block prepolymer was cooled to 60°C, and polyetheramine was added dropwise over 45 minutes under a nitrogen atmosphere. After the addition was complete, the reaction was continued with stirring for 2 hours to obtain the modified epoxy resin. The amount of polyetheramine added was 8% of the mass of the epoxy-silicone block prepolymer, and the stirring speed was 200 rpm.

[0041] The curing agent is prepared by the following method: polyoxypropylene diamine and C12-14 alkyl glycidyl ether are mixed at a mass ratio of 100:10 under a nitrogen atmosphere to obtain mixture ①. 0.2% by mass of triphenylphosphine is added to mixture ① and the mixture is stirred at 200 rpm at 80°C for 2.5 h. After the reaction is completed, the mixture is cooled to room temperature to obtain the curing agent.

[0042] The self-healing component is prepared by the following method:

[0043] B1. Sodium tungstate and hydrogen peroxide urea are mixed at a mass ratio of 2.8:2 to obtain mixture ②. 2.5 times the mass of deionized water is added to mixture ② and stirred to dissolve, thus obtaining a solution. The solution is placed in a -40℃ freezer for 4 hours and then transferred to a freeze dryer for 20 hours of primary drying at 10 Pa and a partition temperature of -30℃. Then, the partition temperature is increased to 25℃ for 6 hours of secondary drying to obtain a solid block. The solid block is crushed and sieved to obtain powder with a particle size of 10 μm. The powder is then coated with molten stearic acid in a fluidized bed at 65℃. After coating, it is sieved again to obtain powder with a particle size of 20 μm, thus obtaining sodium tungstate-hydrogen peroxide urea composite powder.

[0044] B2. Prepare 3% aqueous solutions of gelatin and gum arabic separately to obtain gelatin solution and gum arabic solution, and adjust the pH to 7.5. Add phenylhydrazine to the gelatin solution, followed by the gum arabic solution, adjust the pH to 4.0, stir evenly, cool to 5℃ and solidify for 2 hours, add glutaraldehyde and react for 3 hours, then filter out the solids, wash twice with deionized water, and then dry at -0.08 MPa and 40℃ to constant weight to obtain phenylhydrazine microcapsules. The mass ratio of phenylhydrazine, gelatin solution, gum arabic solution and glutaraldehyde is 1:30:30:0.15.

[0045] B3. Neopentyl glycol diglycidyl ether and hydrogenated castor oil were added to the reactor and stirred at 200 rpm for 30 min under a nitrogen atmosphere. Urea-formaldehyde resin microcapsules, sodium tungstate-hydrogen peroxide urea composite powder, and phenylhydrazine microcapsules were then added at 30°C. The stirring speed was increased to 500 rpm and stirred for 60 min, then reduced to 100 rpm and allowed to mature for 2 h. Degassing was then performed at -0.07 MPa for 20 min, followed by cooling to 20°C to obtain the self-healing component. The mass ratio of neopentyl glycol diglycidyl ether, hydrogenated castor oil, urea-formaldehyde resin microcapsules, sodium tungstate-hydrogen peroxide urea composite powder, and phenylhydrazine microcapsules was 35:3:45:8:10, and the nitrogen flow rate was 45 mL / min.

[0046] The urea-formaldehyde resin microcapsules are prepared by the following method:

[0047] C1. Urea, a 35wt% formaldehyde solution, and deionized water were added to a reaction vessel. Triethanolamine was added to adjust the pH to 8.0. The mixture was stirred at 200 rpm for 90 min at 70°C to obtain a urea-formaldehyde resin prepolymer solution. The mass ratio of urea, formaldehyde solution, and deionized water was 1:2.5:4.

[0048] C2. Cool the urea-formaldehyde resin prepolymer solution to 40°C, add sodium dodecyl sulfate, gum arabic, and deionized water, and stir until completely dissolved. Slowly add dicyclopentadiene and vinylbenzene, and emulsify at 5000 rpm for 15 minutes. The mass ratio of urea-formaldehyde resin prepolymer solution, sodium dodecyl sulfate, gum arabic, deionized water, dicyclopentadiene, and vinylbenzene is 50:0.5:1.0:120:30:2.

[0049] C3. After emulsification, the pH of the emulsion was slowly adjusted to 2.5 with citric acid or hydrochloric acid solution. The temperature was then slowly increased to 55°C at a rate of 1°C / min, and the reaction was stirred at 300 rpm for 3 hours. Ammonium chloride was then added, and the reaction was continued with stirring for another 2 hours. After the reaction was complete, the mixture was vacuum filtered to collect the solid microcapsules. The microcapsules were washed twice alternately with deionized water and anhydrous ethanol, and then vacuum dried to constant weight at 40°C and -0.08 MPa. The microcapsules with a particle size of 50-100 μm were collected after sieving to obtain urea-formaldehyde resin microcapsules.

[0050] Example 2

[0051] A modified epoxy resin permeable brick comprises the following raw materials in parts by weight: 105 parts aggregate, 15 parts modified epoxy resin, 3 parts curing agent, 8 parts composite filler, 0.3 parts activator, 4 parts self-healing component, and 3 parts diluent. The aggregate is quartz sand with a particle size of 5 mm. The composite filler consists of mineral powder, fly ash, and red mud in a mass ratio of 5:5:4. The activator consists of sodium silicate, silane coupling agent KH-560, and nano-silica slurry in a mass ratio of 17:4:3. The diluent consists of neopentyl glycol diglycidyl ether, C12-14 alkyl glycidyl ether, BYK-A530 defoamer, and BYK-2155 wetting and dispersing agent in a mass ratio of 80:30:1.0:2.

[0052] The modified epoxy resin is prepared by the following method:

[0053] A1. Hydrogenated bisphenol A type epoxy resin was mixed with terminal epoxy group polydimethylsiloxane, nitrogen gas was introduced, triphenylphosphine was added, and the mixture was stirred at 110℃ for 2 h to obtain an epoxy-organosilicon block prepolymer. The mass ratio of hydrogenated bisphenol A type epoxy resin, terminal epoxy group polydimethylsiloxane, and triphenylphosphine was 110:12:0.5, the nitrogen gas flow rate was 100 mL / min, and the stirring speed was 200 rpm.

[0054] A2. The epoxy-silicone block prepolymer was cooled to 70°C, and polyetheramine was added dropwise over 30 minutes under a nitrogen atmosphere. After the addition was complete, the reaction was continued with stirring for 1 hour to obtain the modified epoxy resin. The amount of polyetheramine added was 15% of the mass of the epoxy-silicone block prepolymer, and the stirring speed was 400 rpm.

[0055] The curing agent is prepared by the following method: polyoxypropylene diamine and C12-14 alkyl glycidyl ether are mixed at a mass ratio of 100:20 under a nitrogen atmosphere to obtain mixture ①. 0.4% of triphenylphosphine by mass of mixture ① is added, and the mixture is stirred at 400 rpm at 90°C for 1.5 h. After the reaction is completed, the mixture is cooled to room temperature to obtain the curing agent.

[0056] The self-healing component is prepared by the following method:

[0057] B1. Sodium tungstate and hydrogen peroxide urea were mixed at a mass ratio of 3.2:2 to obtain mixture ②. 3.5 times the mass of deionized water was added to mixture ② and stirred to dissolve, thus obtaining a solution. The solution was placed in a -35℃ freezer for 6 hours, and then transferred to a freeze dryer for 20 hours of primary drying at 30 Pa and a partition temperature of -20℃. The partition temperature was then increased to 30℃ for 4 hours of secondary drying to obtain a solid block. The solid block was crushed and sieved to obtain powder with a particle size of 50 μm. The powder was then coated with molten stearic acid in a fluidized bed at 70℃. After coating, the powder was sieved again to obtain powder with a particle size of 60 μm, thus obtaining sodium tungstate-hydrogen peroxide urea composite powder.

[0058] B2. Prepare 4% aqueous solutions of gelatin and gum arabic separately to obtain gelatin solution and gum arabic solution, and adjust the pH to 8.0. Add phenylhydrazine to the gelatin solution, followed by the gum arabic solution, adjust the pH to 4.5, stir evenly, cool to 10℃ and solidify for 1.5h, add glutaraldehyde and react for 2h, then filter out the solids, wash three times with deionized water, and then dry at -0.10MPa and 50℃ to constant weight to obtain phenylhydrazine microcapsules. The mass ratio of phenylhydrazine, gelatin solution, gum arabic solution and glutaraldehyde is 1:40:40:0.2.

[0059] B3. Neopentyl glycol diglycidyl ether and hydrogenated castor oil were added to the reactor and stirred at 300 rpm for 20 min under a nitrogen atmosphere. Urea-formaldehyde resin microcapsules, sodium tungstate-hydrogen peroxide urea composite powder, and phenylhydrazine microcapsules were then added at 35°C. The stirring speed was increased to 600 rpm and stirred for 40 min, followed by a reduction to 150 rpm and maturation for 1 h. Degassing was then performed at -0.09 MPa for 10 min, followed by cooling to 25°C to obtain the self-healing component. The mass ratio of neopentyl glycol diglycidyl ether, hydrogenated castor oil, urea-formaldehyde resin microcapsules, sodium tungstate-hydrogen peroxide urea composite powder, and phenylhydrazine microcapsules was 40:5:50:12:15, and the nitrogen flow rate was 55 mL / min.

[0060] The urea-formaldehyde resin microcapsules are prepared by the following method:

[0061] C1. Add urea, a 40wt% formaldehyde solution, and deionized water to a reaction vessel. Adjust the pH to 8.5 with triethanolamine. Stir at 300 rpm for 60 min at 75°C to obtain a urea-formaldehyde resin prepolymer solution. The mass ratio of urea, formaldehyde solution, and deionized water is 1:3.5:6.

[0062] C2. Cool the urea-formaldehyde resin prepolymer solution to 45°C, add sodium dodecyl sulfate, gum arabic, and deionized water, and stir until completely dissolved. Slowly add dicyclopentadiene and vinylbenzene, and emulsify at 8000 rpm for 10 minutes. The mass ratio of urea-formaldehyde resin prepolymer solution, sodium dodecyl sulfate, gum arabic, deionized water, dicyclopentadiene, and vinylbenzene is 70:1.0:2.0:180:40:5.

[0063] C3. After emulsification, the pH of the emulsion was slowly adjusted to 3.5 with citric acid or hydrochloric acid solution. The temperature was then slowly increased to 60°C at a rate of 2°C / min, and the reaction was stirred at 400 rpm for 2 hours. Ammonium chloride was then added, and the reaction was continued with stirring for another hour. After the reaction was complete, the mixture was vacuum filtered to collect the solid microcapsules. The microcapsules were washed four times each with deionized water and anhydrous ethanol, and then vacuum dried to constant weight at 45°C and -0.10 MPa. The microcapsules with a particle size of 100 μm were collected after sieving, yielding urea-formaldehyde resin microcapsules.

[0064] Example 3

[0065] A modified epoxy resin permeable brick comprises the following raw materials in parts by weight: 100 parts aggregate, 12 parts modified epoxy resin, 2 parts curing agent, 6.5 parts composite filler, 0.2 parts activator, 3 parts self-healing component, and 2 parts diluent. The aggregate is quartz sand with a particle size of 4 mm. The composite filler consists of mineral powder, fly ash, and red mud in a mass ratio of 4:4:3. The activator consists of sodium silicate, silane coupling agent KH-560, and nano-silica slurry in a mass ratio of 15.5:3:2. The diluent consists of neopentyl glycol diglycidyl ether, C12-14 alkyl glycidyl ether, BYK-A530 defoamer, and BYK-2155 wetting and dispersing agent in a mass ratio of 75:25:0.7:1.5.

[0066] The modified epoxy resin is prepared by the following method:

[0067] A1. Hydrogenated bisphenol A type epoxy resin was mixed with epoxy-terminated polydimethylsiloxane, nitrogen gas was introduced, triphenylphosphine was added, and the mixture was stirred at 100°C for 3 hours to obtain an epoxy-organosilicon block prepolymer. The mass ratio of hydrogenated bisphenol A type epoxy resin, epoxy-terminated polydimethylsiloxane, and triphenylphosphine was 100:9:0.4, the nitrogen flow rate was 75 mL / min, and the stirring speed was 300 rpm.

[0068] A2. The epoxy-silicone block prepolymer was cooled to 65°C, and polyetheramine was added dropwise over 37 minutes under a nitrogen atmosphere. After the addition was complete, the reaction was continued with stirring for 1.5 hours to obtain the modified epoxy resin. The amount of polyetheramine added was 12% of the mass of the epoxy-silicone block prepolymer, and the stirring speed was 300 rpm.

[0069] The curing agent is prepared by the following method: polyoxypropylene diamine and C12-14 alkyl glycidyl ether are mixed at a mass ratio of 100:15 under a nitrogen atmosphere to obtain mixture ①. 0.3% of triphenylphosphine by mass of mixture ① is added, and the mixture is stirred at 300 rpm at 85°C for 2.0 h. After the reaction is completed, the mixture is cooled to room temperature to obtain the curing agent.

[0070] The self-healing component is prepared by the following method:

[0071] B1. Sodium tungstate and hydrogen peroxide urea are mixed at a mass ratio of 3.0:2 ​​to obtain mixture ②. 3.0 times the mass of deionized water is added to mixture ② and stirred to dissolve, obtaining a solution. The solution is placed in a -37℃ freezer for 5 hours, and then transferred to a freeze dryer for primary drying at 20 Pa and -25℃ at a partition temperature for 24 hours. Then, the partition temperature is increased to 28℃ for secondary drying for 5 hours to obtain a solid block. The solid block is crushed and sieved to obtain powder with a particle size of 30 μm. The powder is coated with molten stearic acid in a fluidized bed at 67℃. After coating, it is sieved again to obtain powder with a particle size of 40 μm, thus obtaining sodium tungstate-hydrogen peroxide urea composite powder.

[0072] B2. Prepare 3.5% aqueous solutions of gelatin and gum arabic separately to obtain gelatin solution and gum arabic solution, and adjust the pH to 7.7. Add phenylhydrazine to the gelatin solution, followed by the gum arabic solution, adjust the pH to 4.2, stir evenly, cool to 8℃ and cure for 1.8h, add glutaraldehyde and react for 2.5h, then filter out the solids, wash three times with deionized water, and then dry at -0.09MPa and 45℃ to constant weight to obtain phenylhydrazine microcapsules. The mass ratio of phenylhydrazine, gelatin solution, gum arabic solution and glutaraldehyde is 1:35:35:0.2.

[0073] B3. Neopentyl glycol diglycidyl ether and hydrogenated castor oil were added to the reactor. The mixture was stirred at 250 rpm for 25 min under a nitrogen atmosphere. Urea-formaldehyde resin microcapsules, sodium tungstate-hydrogen peroxide urea composite powder, and phenylhydrazine microcapsules were added at 32°C. The stirring speed was increased to 550 rpm and stirred for 50 min. The stirring speed was then reduced to 120 rpm and allowed to mature for 1.5 h. Degassing was then performed at -0.08 MPa for 15 min, followed by cooling to 23°C to obtain the self-healing component. The mass ratio of neopentyl glycol diglycidyl ether, hydrogenated castor oil, urea-formaldehyde resin microcapsules, sodium tungstate-hydrogen peroxide urea composite powder, and phenylhydrazine microcapsules was 37:4:48:10:13, and the nitrogen flow rate was 50 mL / min.

[0074] The urea-formaldehyde resin microcapsules are prepared by the following method:

[0075] C1. Urea, a 38wt% formaldehyde solution, and deionized water were added to a reaction vessel. Triethanolamine was added to adjust the pH to 8.2. The mixture was stirred at 250 rpm for 75 minutes at 73°C to obtain a urea-formaldehyde resin prepolymer solution. The mass ratio of urea, formaldehyde solution, and deionized water was 1:3.0:5.

[0076] C2. Cool the urea-formaldehyde resin prepolymer solution to 42℃, add sodium dodecyl sulfate, gum arabic, and deionized water, and stir until completely dissolved. Slowly add dicyclopentadiene and vinylbenzene, and emulsify at 6500 rpm for 12.5 min. The mass ratio of urea-formaldehyde resin prepolymer solution, sodium dodecyl sulfate, gum arabic, deionized water, dicyclopentadiene, and vinylbenzene is 60:0.8:1.5:150:35:3.5.

[0077] C3. After emulsification, the pH of the emulsion was slowly adjusted to 3.0 with citric acid or hydrochloric acid solution. The temperature was then slowly increased to 57°C at a rate of 1.5°C / min, and the reaction was stirred at 350 rpm for 2.5 h. Ammonium chloride was then added, and the reaction was continued with stirring for another 1.5 h. After the reaction was complete, the mixture was vacuum filtered to collect the solid microcapsules. The microcapsules were washed three times each with deionized water and anhydrous ethanol, respectively. They were then vacuum dried to constant weight at 42°C and -0.09 MPa, and sieved to collect microcapsules with a particle size of 80 μm, yielding urea-formaldehyde resin microcapsules.

[0078] The preparation method of the modified epoxy resin permeable brick described in Examples 1-3 includes the following steps:

[0079] S1. Dry the aggregate at 95℃ to constant weight, add composite filler to the aggregate, and stir at 150 rpm for 4 min; then add activator, modified epoxy resin, self-healing component and diluent, and stir at 500 rpm for 6.5 min; finally add curing agent and stir at 700 rpm for 1.5 min to obtain mixture.

[0080] S2. Transfer the mixture into the mold and press it at 12.5 MPa at room temperature for 45 seconds.

[0081] S3. After demolding, place the brick blank on a curing rack and cure it for 36 hours at 30℃ and 50% relative humidity. Then, continue curing it for 8 days at 25℃ and 55% relative humidity to obtain modified epoxy resin permeable brick.

[0082] Example 4

[0083] Compared with Example 3, the difference in this embodiment is that the preparation method of the modified epoxy resin permeable brick includes the following steps:

[0084] S1. Dry the aggregate at 100℃ to constant weight, add composite filler to the aggregate, and stir at 100 rpm for 5 min; then add activator, modified epoxy resin, self-healing component and diluent, and stir at 400 rpm for 8 min; finally add curing agent and stir at 600 rpm for 2 min to obtain mixture.

[0085] S2. Transfer the mixture into the mold and press it at 10MPa pressure at room temperature for 60s.

[0086] S3. After demolding, place the brick blank on a curing rack and cure it for 48 hours at 25℃ and 40% relative humidity. Then, continue curing it for 10 days at 20℃ and 40% relative humidity to obtain modified epoxy resin permeable brick.

[0087] Example 5

[0088] Compared with Example 3, the difference in this embodiment is that the preparation method of the modified epoxy resin permeable brick includes the following steps:

[0089] S1. Dry the aggregate at 110℃ to constant weight, add composite filler to the aggregate, and stir at 200 rpm for 3 min; then add activator, modified epoxy resin, self-healing component and diluent, and stir at 600 rpm for 5 min; finally add curing agent and stir at 800 rpm for 1 min to obtain mixture.

[0090] S2. Transfer the mixture into the mold and press it at 15MPa pressure at room temperature for 30s.

[0091] S3. After demolding, place the brick blank on a curing rack and cure it for 24 hours at 35℃ and 60% relative humidity. Then, continue curing it for 7 days at 30℃ and 70% relative humidity to obtain modified epoxy resin permeable brick.

[0092] Comparative Example 1

[0093] The difference between this comparative example and Example 3 is that the epoxy resin is not modified, and hydrogenated bisphenol A type epoxy resin is used directly as the raw material.

[0094] Comparative Example 2

[0095] The difference between this comparative example and Example 3 is that a commercially available polyetheramine curing agent was used instead of the curing agent of this application.

[0096] Comparative Example 3

[0097] The difference between this comparative example and Example 3 is that the raw materials do not contain a self-healing agent.

[0098] Performance test

[0099] Fifteen permeable bricks, each 100mm × 100mm × 100mm, prepared according to Examples 1-5 and Comparative Examples 1-3, were taken from each group. Before the test, five bricks from each group were randomly selected according to GB / T 25993 standard to test the permeability coefficient, followed by the compressive strength. These were recorded as the initial permeability coefficient and initial compressive strength, and the average value of these two values ​​was taken. Five permeable bricks from each group were placed in an ultraviolet aging test chamber with an irradiance of 0.90 W / m². 2 The irradiation wavelength was 340nm, the temperature was 60℃, and the continuous irradiation time was 8 hours. Then the temperature was adjusted to 50℃, and the conditions were kept in darkness for 4 hours. One cycle was 12 hours, and the total test duration was 960 hours. After the test, the permeability coefficient and compressive strength were tested according to GB / T 25993 standard, and recorded as UV-aged permeability coefficient and UV-aged compressive strength, respectively. The average value of these two values ​​was taken. The remaining 5 permeable bricks from each group were placed in an aging chamber at 80℃ for 500 hours. After the test, the permeability coefficient and compressive strength were tested according to GB / T 25993 standard, and recorded as thermo-oxidative aging permeability coefficient and thermo-oxidative aging compressive strength, respectively. The average value of these two values ​​was taken. The retention rates of UV-aged permeability coefficient, UV-aged compressive strength, thermo-oxidative aging permeability coefficient, and thermo-oxidative aging compressive strength for each group were calculated.

[0100] UV aging water permeability retention rate = UV aging water permeability / initial water permeability × 100%.

[0101] UV-aged compressive strength retention rate = UV-aged compressive strength / initial compressive strength × 100%.

[0102] Thermo-oxidative aging permeability coefficient retention rate = thermo-oxidative aging permeability coefficient / initial permeability coefficient × 100%.

[0103] Thermo-oxidative aging compressive strength retention rate = thermo-oxidative aging compressive strength / initial compressive strength × 100%.

[0104] The results of the retention rates of water permeability coefficient, compressive strength, water permeability coefficient, and compressive strength under UV aging, thermo-oxidative aging are shown in Table 1.

[0105] Table 1

[0106] UV aging water permeability retention rate / % UV aging compressive strength retention rate / % Thermo-oxidative aging permeability coefficient retention rate / % Thermo-oxidative aging compressive strength retention rate / % Example 1 80.9 85.8 86.3 91.7 Example 2 80.7 85.5 86.6 91.8 Example 3 82.5 87.8 88.3 93.7 Example 4 81.6 86.7 86.9 92.2 Example 5 81.3 86.4 87.2 92.5 Comparative Example 1 49.1 58.3 69.4 64.7 Comparative Example 2 68.5 77.3 79.8 84.6 Comparative Example 3 66.2 73.4 71.9 76.5

[0107] As can be seen from Table 1, the UV aging water permeability coefficient retention rate, UV aging compressive strength retention rate, thermo-oxidative aging water permeability coefficient retention rate, and thermo-oxidative aging compressive strength retention rate of Examples 1-5 of the present invention are higher than those of Comparative Examples 1-3, with Example 3 showing better performance.

[0108] By comparing Example 3 with Comparative Example 1, this invention, through modification, introduces terminally epoxy-based polydimethylsiloxanes into the epoxy resin backbone. The bond energy of the introduced Si-O-Si bonds is higher than that of ultraviolet radiation. When irradiated by ultraviolet light, the Si-O-Si bonds act as energy absorbers and energy dissipation centers, absorbing the energy of the ultraviolet light and releasing it as harmless, low-level heat energy, thus maintaining the integrity of their chemical bonds. Due to the protection of the Si-O-Si bonds, the epoxy resin backbone and cross-linked network are protected from direct attack, the entire load-bearing skeleton is preserved, and the material does not pulverize or soften due to chain breakage, thus maintaining higher strength. Therefore, the pore structure remains stable and will not be blocked by resin pulverization. Simultaneously, the Si-O-Si bonds also exhibit excellent thermal stability, with a decomposition temperature higher than that of ordinary carbon chains. This allows the modified epoxy resin network to better maintain structural integrity under high-temperature environments. Because the key connection points of the polymer network (Si-O-Si bonds and a stable hydrogenated epoxy backbone) have a stronger ability to resist chain breakage and excessive cross-linking at high temperatures, the entire three-dimensional network can maintain higher integrity and slower mechanical property degradation after thermo-oxidative aging.

[0109] Comparing Example 3 with Comparative Example 2, the special curing agent of the present invention uses polypropylene diamine as its backbone. Its long polyether segments (-CH2-CHO-CH2-) act as flexible spacer arms in the cured epoxy network. When the material becomes embrittled under ultraviolet radiation, these flexible segments can effectively absorb and disperse stress through their own curling, stretching, and rotation, preventing the initiation and propagation of microcracks. The flexible segments absorb energy through plastic deformation, allowing the material to maintain a high load-bearing capacity even after aging. The flexible network inhibits the generation of microcracks. Without microcracks, the pore structure inside the permeable brick remains stable and intact. The aggregates are less prone to relative displacement due to embrittlement, which can lead to pore blockage, thus maintaining the unobstructed permeability path. The C12-14 long-chain alkyl groups introduced during the synthesis of the curing agent of the present invention spontaneously migrate to the material surface during and after curing due to their incompatibility with the polar epoxy network, forming a dense, non-polar molecular-level hydrophobic layer. The solubility and diffusion rate of oxygen in nonpolar alkane layers are much lower than in polar polymers. This barrier significantly slows down the penetration of oxygen into the material's interior, inhibiting thermo-oxidative aging reactions at their source. The hydrophobicity of long-chain alkyl groups makes the brick surface difficult to wet with water, effectively preventing the penetration and intrusion of liquid water and avoiding plasticizing and hydrolytic reactions caused by moisture. Because oxygen and moisture are effectively blocked, the rates of thermal oxidation and hydrolysis within the resin network are significantly reduced. The degree of molecular chain breakage and degradation is mitigated, thus better maintaining the integrity of the entire three-dimensional cross-linked network and resulting in a slower decline in compressive strength. A resin matrix that is not severely oxidized internally can better withstand the stress from thermal cycling, maintaining its bonding effect and thus sustaining the interconnected pore structure designed for water permeability over a long period.

[0110] Comparing Example 3 with Comparative Example 3, when microcracks induced by UV aging propagate within the permeable brick, they puncture the urea-formaldehyde resin microcapsules dispersed in the self-healing agent within the matrix. The dicyclopentadiene repair monomer encapsulated within the capsules rapidly flows into the crack fracture surface under capillary action. Simultaneously, the microcracks also tear the phenylhydrazine microcapsules, exposing the sodium tungstate-hydrogen peroxide urea composite powder. After mixing, these three components rapidly undergo a highly efficient ring-opening metathesis polymerization reaction at room temperature, generating a robust polymer that firmly bonds the cracks together. The self-healing process restores the material's load-bearing continuity. This effectively eliminates microcracks, alleviates stress concentration, and allows the material to maintain its load-bearing capacity. The self-healing behavior restores the original structure and integrity of the permeable channels. It prevents local structural collapse and abnormal changes in pore connectivity caused by microcracks, ensuring the long-term stability of the permeability function.

[0111] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A modified epoxy resin permeable brick, characterized in that, The raw materials include the following parts by weight: 95-105 parts aggregate, 8-15 parts modified epoxy resin, 1-3 parts curing agent, 5-8 parts composite filler, 0.1-0.3 parts activator, 2-4 parts self-healing component, and 1-3 parts diluent; The modified epoxy resin is prepared by the following method: A1. Hydrogenated bisphenol A type epoxy resin is mixed with epoxy-terminated polydimethylsiloxane, nitrogen gas is introduced, triphenylphosphine is added, and the mixture is stirred at 90-110℃ for 2-4 hours to obtain epoxy-organosilicon block prepolymer. A2. Cool the epoxy-silicone block prepolymer to 60-70℃, add polyetheramine dropwise over 30-45 minutes under a nitrogen atmosphere, and continue stirring for 1-2 hours after the addition is complete to obtain the modified epoxy resin.

2. The modified epoxy resin permeable brick as described in claim 1, characterized in that, In A1, the mass ratio of hydrogenated bisphenol A type epoxy resin, terminal epoxy polydimethylsiloxane, and triphenylphosphine is (90-110):(6-12):(0.3-0.5), the nitrogen flow rate is 50-100 mL / min, and the stirring speed is 200-400 rpm; in A2, the amount of polyetheramine added is 8-15% of the mass of the epoxy-organosilicon block prepolymer, and the stirring speed is 200-400 rpm.

3. The modified epoxy resin permeable brick as described in claim 1, characterized in that, The aggregate is quartz sand with a particle size of 2-5 mm.

4. The modified epoxy resin permeable brick as described in claim 1, characterized in that, The curing agent is prepared by the following method: polyoxypropylene diamine and C12-14 alkyl glycidyl ether are mixed at a mass ratio of 100:(10-20) under a nitrogen atmosphere to obtain mixture ①. 0.2-0.4% of triphenylphosphine by mass of mixture ① is added, and the mixture is stirred at 200-400 rpm at 80-90℃ for 1.5-2.5 h. After the reaction is completed, the mixture is cooled to room temperature to obtain the curing agent.

5. The modified epoxy resin permeable brick as described in claim 1, characterized in that, The composite filler is composed of mineral powder, fly ash, and red mud in a mass ratio of (3-5):(3-5):(2-4).

6. The modified epoxy resin permeable brick as described in claim 1, characterized in that, The activator is composed of sodium silicate, silane coupling agent KH-560, and nano silica slurry in a mass ratio of (14-17):(2-4):(1-3).

7. The modified epoxy resin permeable brick as described in claim 1, characterized in that, The self-healing component is prepared by the following method: B1. Sodium tungstate and hydrogen peroxide urea are mixed at a mass ratio of 2.8-3.2:2 to obtain mixture ②. 2.5-3.5 times the mass of deionized water of mixture ② are added and stirred to dissolve, thus obtaining a solution. The solution is placed in a freezer at -40 to -35°C for 4-6 hours and then transferred to a freeze dryer for primary drying at 10-30 Pa and a partition temperature of -30 to -20°C for 20-28 hours. Then, the partition temperature is raised to 25-30°C for secondary drying for 4-6 hours to obtain a solid block. The solid block is crushed and sieved to obtain powder with a particle size of 10-50 μm. The powder is coated with molten stearic acid in a fluidized bed at 65-70°C. After coating, it is sieved again to obtain powder with a particle size of 20-60 μm, thus obtaining sodium tungstate-hydrogen peroxide urea composite powder. B2. Prepare 3-4% aqueous solutions of gelatin and gum arabic to obtain gelatin solution and gum arabic solution respectively, and adjust the pH to 7.5-8.0; add phenylhydrazine to gelatin solution, then add gum arabic solution, adjust pH to 4.0-4.5, stir evenly, cool to 5-10℃ and solidify for 1.5-2h, add glutaraldehyde and react for 2-3h, then filter out solids, wash with deionized water 2-3 times, and then dry at -0.08~-0.10MPa and 40~50℃ to constant weight to obtain phenylhydrazine microcapsules; B3. Add neopentyl glycol diglycidyl ether and hydrogenated castor oil to the reactor. Stir at 200-300 rpm for 20-30 min under a nitrogen atmosphere. Add urea-formaldehyde resin microcapsules, sodium tungstate-hydrogen peroxide urea composite powder, and phenylhydrazine microcapsules at 30-35℃. Increase the stirring speed to 500-600 rpm and stir for 40-60 min. Then reduce the stirring speed to 100-150 rpm and mature for 1-2 h. Then degas at -0.07 to -0.09 MPa for 10-20 min and cool to 20-25℃ to obtain the self-healing component.

8. The modified epoxy resin permeable brick as described in claim 7, characterized in that, In B2, the mass ratio of phenylhydrazine, gelatin solution, arabinogalactone, and glutaraldehyde is 1:(30-40):(30-40):(0.15-0.25); in B3, the mass ratio of glycol diglycidyl ether, hydrogenated castor oil, urea-formaldehyde resin microcapsules, sodium tungstate-hydrogen peroxide urea composite powder, and phenylhydrazine microcapsules is (35-40):(3-5):(45-50):(8-12):(10-15), and the nitrogen gas flow rate is 45-55 mL / min.

9. The modified epoxy resin permeable brick as described in claim 1, characterized in that, The diluent is composed of neopentyl glycol diglycidyl ether, C12-14 alkyl glycidyl ether, BYK-A530 defoamer, and BYK-2155 wetting and dispersing agent in a mass ratio of (70-80):(20-30):(0.5-1.0):(1-2).

10. A method for preparing a modified epoxy resin permeable brick according to any one of claims 1-9, characterized in that, Includes the following steps: S1. Dry the aggregate at 100-110℃ to constant weight. Add composite filler to the aggregate and stir at 100-200 rpm for 3-5 minutes. Then add activator, modified epoxy resin, self-healing component and diluent, and stir at 400-600 rpm for 5-8 minutes. Finally, add curing agent and stir at 600-800 rpm for 1-2 minutes to obtain the mixture. S2. Transfer the mixture into the mold and press it into shape at room temperature with a pressure of 10-15MPa for 30-60s. S3. After demolding, place the brick blank on a curing rack and cure it for 24-48 hours at 25-35℃ and 40-60% relative humidity. Then, continue curing it for 7-10 days at 20-30℃ and 40-70% relative humidity to obtain modified epoxy resin permeable brick.