Environment-friendly inorganic polymer reinforcing material and preparation method thereof

Abstract

The application relates to the technical field of building materials, and particularly discloses an environment-friendly inorganic polymer reinforcing material and a preparation method thereof. The environment-friendly inorganic polymer reinforcing material comprises the following raw materials in parts by weight: 15-25 parts of silico-aluminate cement, 10-15 parts of anhydrous calcium sulphoaluminate, 5-8 parts of gypsum, 0.4-0.8 parts of a water reducing agent, 0.1-0.6 parts of an expanding agent, 8-10 parts of modified polyurethane and 60-80 parts of water, wherein the modified polyurethane is obtained by modifying polyurethane with a hydroxyl acrylic resin; and the preparation method comprises the following steps: uniformly mixing and stirring the silico-aluminate cement, the anhydrous calcium sulphoaluminate, the gypsum, the water reducing agent and the expanding agent, then adding the modified polyurethane and appropriate water, and stirring for 3-5 minutes to obtain the environment-friendly inorganic polymer reinforcing material. The composition / product of the application can be used for road surface reinforcement, and has the advantages of high strength and good durability.

Description

Technical Field

[0001] This application relates to the field of building materials technology, and more specifically, to an environmentally friendly inorganic polymer reinforcement material and its preparation method. Background Technology

[0002] In recent years, the rapid development of highway construction in my country has enabled the country to gradually transform from a major highway nation to a highway powerhouse. However, with the acceleration of urbanization and the continuous advancement of infrastructure construction, many structures have developed safety hazards and structural defects due to long-term use or the impact of natural disasters. The need for structural reinforcement is becoming increasingly urgent, especially in the renovation and maintenance of existing structures.

[0003] Currently, most of the high-grade highways already built or under construction in my country use asphalt pavement, with the base layer mostly consisting of a semi-rigid base stabilized by cement and lime. During subgrade construction, limited by factors such as funding and construction period, simple treatment methods such as shallow replacement, cement-lime treatment, and dynamic compaction are often used. However, with the surge in traffic volume, the increasing severity of overloading and exceeding size limits, and the influence of climate and soft soil geological conditions, some highways have developed varying degrees of damage, severely impairing the pavement's performance. Research has found that most of these damages are closely related to foundation problems. Once roadbed damage occurs, repair work becomes extremely difficult.

[0004] To address this issue, trenchless grouting reinforcement has become a common treatment method. This method involves injecting grouting material into cracks or pores in the subgrade and base course to achieve reinforcement and improve the load-bearing capacity of the base course. However, the cement paste commonly used in highway grouting, while inexpensive, suffers from low long-term strength and poor durability, with a service life typically not exceeding two years. This has become a pressing problem to be solved. Therefore, developing durable reinforcement materials has become an urgent need in the field of highway reinforcement. Summary of the Invention

[0005] To improve the durability of reinforcement materials, this application provides an environmentally friendly inorganic polymer reinforcement material and its preparation method.

[0006] In the first aspect, this application provides an environmentally friendly inorganic polymer reinforcement material, which adopts the following technical solution: An environmentally friendly inorganic polymer reinforcement material, comprising the following raw materials in parts by weight: The mixture comprises 15-25 parts of aluminosilicate cement, 10-15 parts of anhydrous calcium sulfoaluminate, 5-8 parts of gypsum, 0.4-0.8 parts of water-reducing agent, 0.1-0.6 parts of expanding agent, 8-10 parts of modified polyurethane, and 60-80 parts of water, wherein the modified polyurethane is obtained by modifying polyurethane with hydroxyl acrylic resin.

[0007] By adopting the above technical solution, mineral materials such as aluminosilicates, anhydrous calcium sulfoaluminate, and gypsum undergo a hydration reaction after being mixed with water, generating stable compounds. The addition of modified polyurethane can fill the cracks and micropores of the reinforcement material, enhancing its density and strength. At the same time, modified polyurethane has a good ability to resist external environmental erosion. Polyurethane modified with hydroxyl acrylic resin can bond with surrounding materials to form a high-strength stone body. One end of its molecular chain contains reactive hydroxyl functional groups, which can undergo cross-linking reactions with the isocyanate groups in the polyurethane curing agent, tightly connecting with the polyurethane molecular chain through chemical bonds. The other end is tightly connected with other raw materials in the reinforcement material, forming a stable network structure, making it difficult for the components in the reinforcement material to migrate during use, thus improving the durability of the reinforcement material.

[0008] Minerals such as aluminosilicates and gypsum provide basic strength for the reinforcement material. The large amount of ettringite produced by the hydration reaction fills the capillary pores of the reinforcement material. At the same time, by introducing the organic waterproof component hydroxyl acrylic resin into the polyurethane molecular chain, it can form a film to seal the capillary pores of the reinforcement material, thereby further improving the waterproof and impermeable capabilities of the reinforcement material. All raw materials work synergistically in the reinforcement material to jointly improve its strength and durability.

[0009] Optionally, the modified polyurethane is prepared by the following steps: Polycaprolactone was heated to 50-60℃ until it melted, and then diisocyanate was added and prepolymerized at 80-90℃ for 1-2 hours. Chain extender and catalyst were added sequentially, and the reaction was carried out for 4-5 hours. After the reaction was completed, a certain amount of hydroxyl acrylic resin was added and reacted at 55-65℃ for 4-5 hours. The temperature was then lowered to 30-40℃, and triethylamine and deionized water were added and emulsified at high speed for 10-15 minutes to obtain the modified polyurethane.

[0010] By employing the above technical solution, the isocyanate groups in the isocyanate group can react with the hydroxyl groups of polycaprolactone to form polyurethane chains. Further addition of chain extenders, crosslinking agents, and catalysts further extends the length and crosslinking density of the polyurethane molecular chains, accelerating the formation of the polyurethane chains. The formed polyurethane undergoes a crosslinking reaction with hydroxyl acrylic resin, giving the modified polyurethane the advantages of both hydroxyl acrylic resin and polyurethane. Simultaneously, the introduction of highly stable acrylate groups into the polyurethane molecular chains endows the polyurethane with good chemical and thermal stability, enabling the prepared material to maintain performance stability even under harsh environmental conditions.

[0011] Hydroxyacrylate resin exhibits excellent adhesion to other raw materials in the reinforcement material, ensuring a tight bond between them. This strong bond prevents moisture and other harmful substances from penetrating the reinforcement material, further enhancing its durability.

[0012] Optionally, in the preparation process of the modified polyurethane, the weight ratio of polycaprolactone, diisocyanate and hydroxyl acrylic resin is 1:0.45-0.6:0.25-0.5.

[0013] Optionally, the diisocyanate is an aromatic isocyanate.

[0014] By adopting the above technical solution, aromatic isocyanates have high reactivity, and the benzene ring structure on them provides rigidity and strength to the polyurethane segments. Combined with the flexible segments provided by polycaprolactone, the strength of the polyurethane is significantly improved. Furthermore, the rigid benzene ring structure brings good stability to the polyurethane. Therefore, the modified polyurethane can maintain good performance in harsh environments, thereby improving the durability of the prepared reinforcement material.

[0015] Optionally, the chain extender is an aromatic diamine chain extender.

[0016] By adopting the above technical solution, during the modification process, the chain extender and isocyanate together constitute the hard segments in the polyurethane molecule. The strength of the polyurethane depends on the physical cross-linking points formed by the aggregation of molecular hard segments. Therefore, the choice of chain extender affects the final performance of the obtained polyurethane. Choosing aromatic diamine as the chain extender, its rigid benzene ring and strongly polar urea group make the polyurethane material have higher strength and stability when subjected to external forces. In addition, the aromatic diamine chain extender has good compatibility with hydroxyl acrylic resin, which helps the polyurethane and hydroxyl acrylic resin to react fully, improve the stability of the modified polyurethane, and further improve the performance of the modified polyurethane.

[0017] Optionally, the expanding agent is calcium oxide.

[0018] By adopting the above technical solution, calcium oxide expansion agent can reduce the internal stress of the material and fill its pores, thereby improving the density of the material. Adding calcium oxide can enhance the flexibility of the material, which helps it to better withstand external stress and environmental changes, thereby improving the durability of the reinforced material.

[0019] Optionally, 0.3-0.5 parts of lithium salt early strength agent are also added to the raw materials.

[0020] By adopting the above technical solution, lithium salt early-strength agents can increase the alkalinity of sulfoaluminate cement, which is beneficial to [Al(OH)6]. 3- Octahedral nucleation and polymerization accelerate the hydration reaction of cement, enabling the material to reach higher strength in a shorter time and promoting the hardening process of the reinforcing material, thus shortening the construction cycle.

[0021] Secondly, this application provides a method for preparing an environmentally friendly inorganic polymer reinforcement material, employing the following technical solution: A method for preparing an environmentally friendly inorganic polymer reinforcement material includes the following preparation steps: Take aluminosilicate cement, anhydrous calcium sulfoaluminate, gypsum, water-reducing agent and expansion agent, mix them evenly, then add modified polyurethane and an appropriate amount of water and stir for 3-5 minutes to obtain the reinforcement material.

[0022] In summary, this application has the following beneficial effects: 1. Because this application uses anhydrous calcium sulfoaluminate combined with gypsum, the resulting mixture exhibits micro-expansion properties, which can offset shrinkage stress and improve the later-stage strength of the reinforcement material. Using aluminosilicate cement, anhydrous calcium sulfoaluminate, and other materials as main raw materials, combined with modified polyurethane and various additives, the synergistic effect between the inorganic components enhances the durability of the reinforcement material. Further integration with organic reinforcing phase modified polyurethane further improves the strength and durability of the material.

[0023] 2. In this application, hydroxyl acrylic resin is preferably used to modify polyurethane. The cross-linking reaction between hydroxyl acrylic resin and polyurethane introduces hydroxyl and acrylate groups into the polyurethane, which greatly improves the weather resistance of polyurethane, enabling it to better resist the erosion of the external environment. Furthermore, the network structure formed by its cross-linking further fixes the components in the reinforcing material, improving the strength and durability of the reinforcing material. Detailed Implementation

[0024] The present application will be further described in detail below with reference to the embodiments.

[0025] Unless otherwise specified in the examples, the procedures should be performed under standard conditions or conditions recommended by the manufacturer. Reagents or instruments whose manufacturers are not specified are all commercially available products.

[0026] Hydroxyacrylate resin was purchased from Jining Sanshi Biotechnology Co., Ltd., with a hydroxyl value of 80; polycaprolactone was purchased from Shanghai Hongzhuang Chemical Technology Co., Ltd., with a density of 1.07 g / cm³. 3 The aluminosilicate cement was purchased from Taizhou Yigao E-commerce Co., Ltd., with a compressive strength of 70 MPa; the gypsum was purchased from Hebei Mingzhe Mineral Products Co., Ltd., model MZ-00.

[0027] Preparation examples of raw materials and / or intermediates Preparation Example 1 A modified polyurethane, prepared by the following steps: 30 kg of polycaprolactone was heated to 55 °C and melted. Then, 13.5 kg of toluene diisocyanate (diisocyanate) was added and prepolymerized at 85 °C for 2 h. 2.1 kg of 3,3-dichloro-4,4-diaminophenylmethane (chain extender) and 2.07 kg of dibutyltin dilaurate (catalyst) were added sequentially, and the reaction was carried out for 4 h. After the reaction was completed, 7.5 kg of hydroxyl acrylic resin was added and reacted at 60 °C for 4 h. The temperature was then lowered to 30 °C, and 1.56 kg of triethylamine and 144 kg of deionized water were added. The mixture was stirred at high speed and emulsified for 10 min. After removing impurities under reduced pressure, the modified polyurethane was obtained.

[0028] Preparation Example 2 A modified polyurethane, prepared by the following steps: Take 30 kg of polycaprolactone, heat it to 50°C until it melts, then add 18 kg of toluene diisocyanate (diisocyanate) and prepolymerize at 90°C for 2 h. Then add 2.1 kg of 3,3-dichloro-4,4-diaminophenylmethane (chain extender) and 2.07 kg of dibutyltin dilaurate (catalyst) in sequence, and react for 5 h. After the reaction is completed, add 11.25 kg of hydroxyl acrylic resin and react at 55°C for 5 h. Cool down to 35°C, add 1.56 kg of triethylamine and 144 kg of deionized water, and emulsify at high speed for 12.5 min. After removing impurities under reduced pressure, the modified polyurethane is obtained.

[0029] Preparation Example 3 A modified polyurethane, prepared by the following steps: 30 kg of polycaprolactone was heated to 60 °C and melted. Then, 15.6 kg of toluene diisocyanate (diisocyanate) was added and prepolymerized at 80 °C for 2 h. 2.1 kg of 3,3-dichloro-4,4-diaminophenylmethane (chain extender) and 2.07 kg of dibutyltin dilaurate (catalyst) were added sequentially, and the reaction was carried out for 5 h. After the reaction was completed, 15 kg of hydroxyl acrylic resin was added and reacted at 65 °C for 5 h. The temperature was then lowered to 40 °C, and 1.56 kg of triethylamine and 144 kg of deionized water were added. The mixture was stirred at high speed and emulsified for 15 min. After removing impurities under reduced pressure, the modified polyurethane was obtained.

[0030] Preparation Example 4 A modified polyurethane, which differs from Preparation Example 1 in that the diisocyanate used in this preparation example is isophorone diisocyanate.

[0031] Preparation Example 5 A modified polyurethane differs from Preparation Example 1 in that the chain extender used in this preparation example is dimethylolpropionic acid.

[0032] Preparation Example 6 A polyurethane aqueous solution, prepared by the following steps: Take 30 kg of polycaprolactone, heat it to 55°C until it melts, then add 13.5 kg of toluene diisocyanate (diisocyanate) and prepolymerize at 85°C for 2 h. Then add 2.1 kg of 3,3-dichloro-4,4-diaminophenylmethane (chain extender) and 2.07 kg of dibutyltin dilaurate (catalyst) in sequence. After reacting for 4 h, continue to react at 60°C for 4 h. Cool down to 30°C, add 1.56 kg of triethylamine and 144 kg of deionized water, stir and emulsify at high speed for 10 min. After removing impurities under reduced pressure, the polyurethane aqueous solution is obtained. Example

[0033] Example 1 An environmentally friendly inorganic polymer reinforcement material is prepared by the following steps: Take 15 kg of aluminosilicate cement, 15 kg of anhydrous calcium sulfoaluminate, 5 kg of gypsum, 0.8 kg of sodium lignosulfonate (water-reducing agent), and 0.1 kg of calcium oxide (expansion agent), mix them evenly, then add 60 kg of water and 10 kg of modified polyurethane and stir for 3 minutes to obtain the reinforcing material. The modified polyurethane is the one prepared in Preparation Example 1.

[0034] Example 2 An environmentally friendly inorganic polymer reinforcement material is prepared by the following steps: Take 20 kg of aluminosilicate cement, 12.5 kg of anhydrous calcium sulfoaluminate, 6.5 kg of gypsum, 0.6 kg of sodium lignosulfonate (water-reducing agent), and 0.3 kg of calcium oxide (expansion agent), mix them evenly, then add 70 kg of water and 9 kg of modified polyurethane and stir for 4 minutes to obtain the reinforcing material. The modified polyurethane is the one prepared in Preparation Example 2.

[0035] Example 3 An environmentally friendly inorganic polymer reinforcement material is prepared by the following steps: Take 25 kg of aluminosilicate cement, 10 kg of anhydrous calcium sulfoaluminate, 8 kg of gypsum, 0.4 kg of sodium lignosulfonate (water-reducing agent), and 0.6 kg of calcium oxide (expansion agent), mix them evenly, then add 80 kg of water and 8 kg of modified polyurethane and stir for 5 minutes to obtain the reinforcing material. The modified polyurethane is the one prepared in Preparation Example 3.

[0036] Example 4 An environmentally friendly inorganic polymer reinforcement material, which differs from Example 1 in that the modified polyurethane used in this example is the one prepared in Preparation Example 4.

[0037] Example 5 An environmentally friendly inorganic polymer reinforcement material, which differs from Example 1 in that the modified polyurethane used in this example is the one prepared in Preparation Example 5.

[0038] Example 6 An environmentally friendly inorganic polymer reinforcement material, which differs from Example 1 in that the expanding agent used in this example is aluminum sulfate.

[0039] Example 7 An environmentally friendly inorganic polymer reinforcement material, which differs from Example 1 in that 0.3 kg of lithium carbonate (lithium salt early strength agent) is also added in this example. The preparation includes the following steps: Take 15 kg of aluminosilicate cement, 15 kg of anhydrous calcium sulfoaluminate, 5 kg of gypsum, 0.8 kg of sodium lignosulfonate (water-reducing agent), 0.3 kg of lithium carbonate, and 0.1 kg of calcium oxide (expansion agent), mix them evenly, then add 60 kg of water and 10 kg of modified polyurethane and stir for 3 minutes to obtain the reinforcing material. The modified polyurethane is the one prepared in Preparation Example 1.

[0040] Example 8 An environmentally friendly inorganic polymer reinforcement material, which differs from Example 1 in that 0.5 kg of lithium carbonate (lithium salt early strength agent) is also added in this example. Comparative Example Comparative Example 1 An environmentally friendly inorganic polymer reinforcement material, which differs from Example 1 in that no modified polyurethane was added in this comparative example.

[0041] Comparative Example 2 An environmentally friendly inorganic polymer reinforcement material, which differs from Comparative Example 1 in that the polyurethane prepared in Preparation Example 6 is added to this comparative example.

[0042] Performance testing Test method / test method for compressive strength: Refer to Section A.0.2 of GB / T 50448-2015 "Technical Specification for Application of Cement-based Grouting Materials" to mix cement-based grouting materials. Pour the reinforcing materials prepared in Examples 1-8 and Comparative Examples 1-2 into a 40×40×160mm mold for molding. Demold after 24 hours. After demolding, cure in a standard curing chamber. Test the compressive strength after 7 days of curing. Water resistance: The water resistance was tested according to SZ-G-B04-2007 "Technical Specification for Polymer Grouting Reinforcement of Highway Subgrade and Base". The polymer reinforcement material was made into a 40×40×160mm sample, demolded after 24 hours, and cured in a standard curing chamber. After curing for 28 days, its mass was measured and recorded as m1. Then it was immersed in water for 30 days and its mass was measured and recorded as m2. The mass loss rate was calculated. This index was used to characterize the internal water resistance of the concrete. Durability: The resistance to chloride ion penetration was tested according to the electrical flux method in GB / T50082—2009 "Standard for Test Methods of Long-term Performance and Durability of Ordinary Concrete". A cylindrical specimen with a diameter of (100±1) mm and a height of (50±2) mm was used. The electrical flux of the specimen was measured after 24 hours of pre-wetting. The higher the electrical flux, the worse the resistance to chloride ion penetration, that is, the poorer the durability of the specimen.

[0043] Table 1 Test Data Example 1 18.9 69.8 96.36 1229 Example 2 18.7 69.5 96.18 1234 Example 3 18.8 69.7 96.22 1232 Example 4 17.3 68.5 94.79 1326 Example 5 16.9 68.1 94.01 1339 Example 6 17.5 68.7 93.49 1428 Example 7 19.3 71.1 96.58 1108 Example 8 19.5 71.3 96.61 1105 Comparative Example 1 13.4 48.3 69.38 1983 Comparative Example 2 16.8 55.1 74.29 1876 Combining Examples 1-3 and Comparative Examples 1-2 with Table 1, it can be seen that the test data of Examples 1-3 are significantly better than those of Comparative Examples 1-2. This indicates that the addition of modified polyurethane can fill the cracks and micropores in the reinforcement material, improve its density, and thus enhance its strength. Simultaneously, polyurethane also possesses excellent resistance to external environmental erosion, greatly extending the service life of the reinforcement material and preventing the penetration of moisture and other harmful substances, thereby improving its durability. Further modification of the polyurethane with hydroxyl acrylic resin improves its compatibility with other raw materials, forming a network structure within the material. This ensures the stable existence of each raw material, preventing migration and further enhancing the durability of the reinforcement material.

[0044] Combining Examples 1 and 4 with Table 1, it can be seen that the test data of Example 1 are significantly better than those of Example 4. This indicates that diisocyanate affects the performance of the modified polyurethane during the preparation process. Choosing an aromatic isocyanate with a benzene ring structure makes the polyurethane not only have better rigidity and strength, but also higher stability, thus improving the durability of the reinforcement material.

[0045] Combining Examples 1 and 5 with Table 1, it can be seen that the test data of Example 1 are significantly better than those of Example 5. This indicates that the selection of aromatic diamine chain extenders provides more physical crosslinking points for polyurethane, which is beneficial for the full reaction between polyurethane and hydroxyl acrylic resin, thereby improving the modification effect of polyurethane. At the same time, the rigid benzene ring and the strongly polar urea group on it give the modified polyurethane better strength and stability, improving the strength and durability of the final reinforced material.

[0046] Combining Examples 1 and 6 with Table 1, it can be seen that the experimental data of Example 1 are better than those of Example 6. This indicates that selecting calcium oxide as an expansion agent can produce compensating shrinkage, effectively reducing the internal stress of the reinforced material. It can also react with substances in the reinforced material to generate hardened calcium carbonate and other crystals, thereby improving the durability of the material.

[0047] Combining Examples 1 and 7-8 with Table 1, it can be seen that the experimental data of Example 1 are better than those of Examples 7-8. This indicates that the addition of lithium salt early strength agent can react with sulfoaluminate, accelerate the cement hydration process, promote the generation of more hydration products, fill the pores of concrete to reduce the porosity of the reinforcement material, and the dense microstructure helps to prevent the intrusion of moisture and harmful substances, thereby improving the durability of the reinforcement material.

[0048] This specific embodiment is merely an explanation of this application and is not intended to limit it. After reading this specification, those skilled in the art can make modifications to this embodiment without contributing any inventive step, but such modifications are protected by patent law as long as they fall within the scope of the claims of this application.

Claims

1. An environmentally friendly inorganic polymer reinforcement material, characterized in that, It is made from the following raw materials in parts by weight: 15-25 parts aluminosilicate cement, 10-15 parts anhydrous calcium sulfoaluminate, 5-8 parts gypsum, 0.4-0.8 parts water-reducing agent, 0.1-0.6 parts expanding agent, 8-10 parts modified polyurethane, and 60-80 parts water. The modified polyurethane is prepared by the following steps: polycaprolactone is heated to 50-60℃ and melted, diisocyanate is added and prepolymerized at 80-90℃ for 1-2 hours, chain extender and catalyst are added sequentially, and the reaction is carried out for 4-5 hours. After the reaction is completed, a certain amount of hydroxyl acrylic resin is added and reacted at 55-65℃ for 4-5 hours. The temperature is then lowered to 30-40℃, and triethylamine and deionized water are added and emulsified at high speed for 10-15 minutes to obtain the modified polyurethane. In the preparation process of the modified polyurethane, the weight ratio of polycaprolactone, diisocyanate and hydroxyl acrylic resin is 1:0.45-0.6:0.25-0.

5. The expanding agent is calcium oxide.

2. The environmentally friendly inorganic polymer reinforcement material according to claim 1, characterized in that: The diisocyanate is an aromatic isocyanate.

3. The environmentally friendly inorganic polymer reinforcement material according to claim 1, characterized in that: The chain extender is an aromatic diamine chain extender.

4. A method for preparing an environmentally friendly inorganic polymer reinforcement material according to any one of claims 1-3, characterized in that, The preparation steps include the following: take aluminosilicate cement, anhydrous calcium sulfoaluminate, gypsum, water-reducing agent and expansion agent, mix and stir evenly, then add modified polyurethane and an appropriate amount of water and stir for 3-5 minutes to obtain the reinforcement material.