An aging-resistant polymer repair mortar and its preparation method

Abstract

This invention discloses an aging-resistant polymer repair mortar and its preparation method, comprising 10-20 parts silicate cement, 20-40 parts quartz sand, 2-4 parts polyvinyl alcohol resin emulsion, 2-4 parts polyurethane emulsion, 0.05-0.5 parts crosslinking agent, 1-2 parts inorganic nanoparticle powder, 1-2 parts graphite, 0.05-0.1 parts water-reducing agent, and 15-30 parts water. This invention utilizes an emulsion blending method, where thorough stirring allows PVA and PU to crosslink and form an interpenetrating network structure. In this structure, the two polymers intertwine and permeate each other, forming a stable network system. This allows PVA and PU to maintain their individual properties while complementing and synergistically enhancing the overall performance of the polymer repair mortar.

Description

Technical Field

[0001] This invention belongs to the field of concrete repair materials, specifically relating to an aging-resistant polymer repair mortar and its preparation method. Background Technology

[0002] Polymer repair mortar is a high-performance repair material that combines the adhesiveness of polymer materials with the durability of inorganic materials, forming a new type of concrete repair mortar. Its characteristics are mainly reflected in the following aspects: (1) High strength and early strength development: Polymer repair mortar has excellent compressive and tensile strength. Its unique polymer formula enables it to reach high strength in a short time, making it particularly suitable for occasions that require rapid repair and restoration of functionality. (2) Excellent adhesion: This repair mortar can form a good bond with various substrates (such as concrete, masonry, metal, etc.), ensuring that the repair layer is tightly connected to the original structure and avoiding peeling or cracking. (3) Excellent construction performance: Polymer repair mortar has low viscosity, making it easy to mix and construct. At the same time, it can be constructed in a wide temperature range and is not affected by the humidity of the substrate, making construction convenient and quick. Therefore, it is suitable for the repair and reinforcement of various concrete structures, masonry structures, metal structures, etc. Its excellent performance and convenient construction make it an ideal choice in the field of modern building maintenance and reinforcement.

[0003] Although polymer repair mortars exhibit excellent performance in the short term, their long-term durability remains uncertain. Since the long-term performance of polymer repair mortars in natural environments is affected by various factors, such as climate change and chemical corrosion, improving their long-term durability and anti-aging properties is a pressing issue that needs to be addressed. Summary of the Invention

[0004] Purpose of the invention: The technical problem to be solved by the present invention is to provide a polymer repair mortar with long-term durability and its preparation method, which addresses the shortcomings of the prior art.

[0005] To achieve the above objectives, the technical solution adopted by the present invention is as follows: An aging-resistant polymer repair mortar, comprising the following components in parts by weight: 10-20 parts of silicate cement are used as a base material to provide strength and durability to the mortar.

[0006] 20-40 parts of quartz sand are used as aggregate to increase the volume and strength of the mortar.

[0007] 2-4 parts of polyvinyl alcohol resin emulsion; 2-4 parts of polyurethane emulsion; Crosslinking agent 0.05-0.5 parts; 1-2 parts of inorganic nanoparticle powder; when incorporated into PVA, it can absorb or scatter ultraviolet rays and heat, reducing damage to the resin and thus improving the resin's heat resistance, light resistance and aging resistance.

[0008] 1-2 parts graphite; Add 0.05 to 0.1 parts of water-reducing agent to improve the flowability of mortar.

[0009] 15-30 parts water.

[0010] More preferably, the aging-resistant polymer repair mortar of the present invention comprises the following components in parts by weight: 15 parts of silicate cement; 28 parts of quartz sand; 3 parts of polyvinyl alcohol resin emulsion (PVA); 2 parts polyurethane emulsion (PU); Crosslinking agent 0.05-0.5 parts; 1.5 parts of inorganic nanoparticle powder; 1.5 parts graphite; 0.08 parts water-reducing agent; 25 parts water.

[0011] Furthermore, the particle size of the quartz sand is 20-80 mesh; the crosslinking agent is selected from any one of isocyanate, phthalic anhydride, and silicone.

[0012] Furthermore, the polyvinyl alcohol resin emulsion is composed of polyvinyl alcohol resin, cationic emulsifier and water; wherein the mass percentage of polyvinyl alcohol resin is 15-30%, the mass percentage of cationic emulsifier is 5-8%, and the remainder is water.

[0013] Preferably, the cationic emulsifier is an alkyl quaternary ammonium salt emulsifier, more preferably any one of 1831, 18331 or 1621 alkyl quaternary ammonium salt emulsifiers.

[0014] Furthermore, the polyurethane emulsion is composed of polyurethane resin, dispersant, stabilizer and water; wherein the mass percentage of polyurethane resin is 30-50%, the mass percentage of dispersant is 3-5%, the mass percentage of stabilizer is 2-6%, and the remainder is water.

[0015] Preferably, the dispersant is polyoxyethylene alkylphenol ether or polyoxyethylene fatty alcohol ether; the stabilizer is any one or a combination of two or more of dilauryl thiodipropionate, Tinuvin 770, Tinuvin 327, and Tinuvin 328.

[0016] Furthermore, the inorganic nanoparticle powder is any one or a combination of two or more of silicon dioxide, aluminum oxide, and magnesium oxide.

[0017] Furthermore, the present invention also provides a method for preparing the above-mentioned aging-resistant polymer repair mortar, comprising the following steps: (1) Mix polyvinyl alcohol resin emulsion, polyurethane emulsion and crosslinking agent, and crosslink at 20-50 degrees Celsius under stirring to form a PVA-PU mixed emulsion with an interpenetrating network structure; (2) Add the water-reducing agent to the water, then add the inorganic nanoparticle powder and graphite, and ultrasonically disperse them evenly to obtain a suspension solution; (3) Stir and mix silicate cement with the PVA-PU mixed emulsion in step (1), and then add the suspension solution in step (2); (4) Add quartz sand while stirring and mechanically stir to form a uniform mortar. Beneficial effects

[0018] (1) This invention utilizes an emulsion blending method, through thorough stirring, to allow PVA and PU to crosslink and form an interpenetrating network structure. In this structure, the two polymers intertwine and permeate each other, forming a stable network system. This allows PVA and PU to maintain their respective properties while complementing and synergistically enhancing the overall performance and aging resistance of the polymer repair mortar.

[0019] (2) The present invention utilizes the functional groups such as hydroxyl and amino groups on PVA and PU to uniformly coat the cement particles, thereby improving the fluidity of cement mortar, reducing water retention, and promoting cement hydration reaction to enhance the repair strength of mortar.

[0020] (3) The present invention also improves the wear resistance and light resistance of polymer repair mortar by introducing inorganic nanoparticle powder and graphite, thereby further improving the overall aging resistance. Detailed Implementation

[0021] The present invention can be better understood from the following embodiments. Example 1

[0022] (1) Mix 30g of polyvinyl alcohol resin emulsion, 20g of polyurethane emulsion and 2g of isocyanate crosslinking agent, and crosslink at 40 degrees Celsius for 20min under stirring at 400r / min to form a PVA-PU mixed emulsion with an interpenetrating network structure.

[0023] The polyvinyl alcohol resin emulsion consists of polyvinyl alcohol resin, cationic emulsifier and water. The mass percentage of polyvinyl alcohol resin is 20%, the mass percentage of alkyl quaternary ammonium salt emulsifier is 6%, and the remainder is water.

[0024] The polyurethane emulsion is composed of polyurethane resin, dispersant, stabilizer and water; wherein, the mass percentage of polyurethane resin is 40%, the mass percentage of dispersant polyoxyethylene alkylphenol ether is 4%, the mass percentage of stabilizer dilauryl thiodipropionate is 4%, and the remainder is water.

[0025] (2) Add 0.8g of polycarboxylate superplasticizer to 250g of water, then add 15g of magnesium oxide nanoparticle powder and 15g of graphite, and disperse evenly by ultrasonication to obtain a suspension solution; (3) Mix 150g of silicate cement with the PVA-PU mixed emulsion in step (1), and then add the suspension solution in step (2); (4) Add 280g of 50-mesh quartz sand while stirring, and mechanically stir to form a uniform mortar. Example 2

[0026] (1) Mix 20g of polyvinyl alcohol resin emulsion, 40g of polyurethane emulsion and 0.5g of isocyanate crosslinking agent, stir at 400r / min and crosslink at 40 degrees Celsius for 20min to form a PVA-PU mixed emulsion with an interpenetrating network structure.

[0027] The polyvinyl alcohol resin emulsion consists of polyvinyl alcohol resin, cationic emulsifier and water. The mass percentage of polyvinyl alcohol resin is 15%, the mass percentage of alkyl quaternary ammonium salt emulsifier is 8%, and the remainder is water.

[0028] The polyurethane emulsion is composed of polyurethane resin, dispersant, stabilizer and water; wherein, the mass percentage of polyurethane resin is 30%, the mass percentage of dispersant polyoxyethylene fatty alcohol ether is 5%, the mass percentage of stabilizer Tinuvin 770 is 6%, and the remainder is water.

[0029] (2) Add 1g of polycarboxylate superplasticizer to 150g of water, then add 10g of magnesium oxide nanoparticle powder and 10g of graphite, and ultrasonically disperse evenly to obtain a suspension solution; (3) Mix 100g of silicate cement with the PVA-PU mixed emulsion in step (1), and then add the suspension solution in step (2); (4) Under stirring conditions, add 200g of 50-mesh quartz sand and mechanically stir to form a uniform mortar. Example 3

[0030] (1) Mix 40g of polyvinyl alcohol resin emulsion, 20g of polyurethane emulsion and 5g of silicone crosslinking agent, and crosslink at 40 degrees Celsius for 20min under stirring at 400r / min to form a PVA-PU mixed emulsion with an interpenetrating network structure.

[0031] The polyvinyl alcohol resin emulsion consists of polyvinyl alcohol resin, cationic emulsifier and water, with polyvinyl alcohol resin accounting for 30% by mass, alkyl quaternary ammonium salt emulsifier accounting for 5% by mass, and the remainder being water.

[0032] The polyurethane emulsion is composed of polyurethane resin, dispersant, stabilizer and water; wherein, the mass percentage of polyurethane resin is 50%, the mass percentage of dispersant polyoxyethylene fatty alcohol ether is 3%, the mass percentage of stabilizer Tinuvin 770 is 2%, and the remainder is water.

[0033] (2) Add 0.5g of polycarboxylate superplasticizer to 300g of water, then add 20g of magnesium oxide nanoparticle powder and 20g of graphite, and disperse evenly by ultrasonication to obtain a suspension solution; (3) Mix 200g of silicate cement with the PVA-PU mixed emulsion in step (1), and then add the suspension solution in step (2); (4) Under stirring conditions, add 400g of 50-mesh quartz sand and mechanically stir to form a uniform mortar. Comparative Example 1

[0034] (1) Mix 30g of polyvinyl alcohol resin emulsion and 2g of isocyanate crosslinking agent, stir at 400r / min, and crosslink at 40 degrees Celsius for 20min to obtain PVA crosslinked emulsion.

[0035] The polyvinyl alcohol resin emulsion consists of polyvinyl alcohol resin, cationic emulsifier and water. The mass percentage of polyvinyl alcohol resin is 20%, the mass percentage of alkyl quaternary ammonium salt emulsifier is 6%, and the remainder is water.

[0036] (2) Add 0.8g of polycarboxylate superplasticizer to 250g of water, then add 15g of magnesium oxide nanoparticle powder and 15g of graphite, and disperse evenly by ultrasonication to obtain a suspension solution; (3) Mix 150g of silicate cement with the PVA crosslinking emulsion in step (1), and then add the suspension solution in step (2); (4) Add 280g of 50-mesh quartz sand while stirring, and mechanically stir to form a uniform mortar. Comparative Example 2

[0037] (1) Mix 20g of polyurethane emulsion and 2g of isocyanate crosslinking agent, stir at 400r / min, and crosslink at 40 degrees Celsius for 20min to form PU crosslinked emulsion.

[0038] The polyurethane emulsion is composed of polyurethane resin, dispersant, stabilizer and water; the polyurethane resin accounts for 40% by mass, the dispersant polyoxyethylene alkylphenol ether accounts for 4% by mass, the stabilizer dilauryl thiodipropionate accounts for 4% by mass, and the remainder is water.

[0039] (2) Add 0.8g of polycarboxylate superplasticizer to 250g of water, then add 15g of magnesium oxide nanoparticle powder and 15g of graphite, and disperse evenly by ultrasonication to obtain a suspension solution; (3) Mix 150g of silicate cement with the PU crosslinking emulsion in step (1), and then add the suspension solution in step (2); (4) Add 280g of 50-mesh quartz sand while stirring, and mechanically stir to form a uniform mortar.

[0040] According to the testing standard JC / T 2381-2016 "Repair Mortar", the relevant performance indicators of each example and comparative example were determined, and the results are shown in Table 1.

[0041] Table 1

[0042] As shown in Table 1, the performance of all three embodiments of this application is significantly higher than that of the JC / T 2381-2016 "Repair Mortar" industry standard. The 28-day compressive strength is not less than 25 MPa, and the flexural strength is not less than 7 MPa. Furthermore, in terms of long-term durability, the polymer repair mortar of this invention exhibits excellent performance, significantly outperforming the comparative examples and existing flexible repair mortars in several test items, including thermal aging, 25 freeze-thaw cycles, and erosion resistance coefficient. Moreover, compared to Comparative Examples 1 and 2, which use a single polyvinyl alcohol resin emulsion or polyurethane emulsion as the organic reinforcing component, this invention demonstrates a synergistic effect by co-crosslinking polyvinyl alcohol resin and polyurethane to form an interpenetrating network structure, thus significantly improving long-term durability.

[0043] This invention provides a concept and method for developing an aging-resistant polymer repair mortar. Many methods and approaches exist for implementing this technical solution; the above description is merely a preferred embodiment. It should be noted that those skilled in the art can make various improvements and modifications without departing from the principles of this invention, and these improvements and modifications should also be considered within the scope of protection of this invention. All components not explicitly stated in this embodiment can be implemented using existing technologies.

Claims

1. An aging-resistant polymer repair mortar, characterized in that, Includes the following components by mass: 10-20 parts of silicate cement; 20-40 parts of quartz sand; 2-4 parts of polyvinyl alcohol resin emulsion; 2-4 parts of polyurethane emulsion; Crosslinking agent 0.05-0.5 parts; 1-2 parts of inorganic nanoparticle powder; 1-2 parts graphite; Water-reducing agent 0.05-0.1 parts; 15-30 parts water; The crosslinking agent is selected from any one of isocyanate, phthalic anhydride, and silicone; The polyvinyl alcohol resin emulsion is composed of polyvinyl alcohol resin, cationic emulsifier and water; The polyurethane emulsion is composed of polyurethane resin, dispersant, stabilizer and water; The aging-resistant polymer repair mortar is prepared through the following steps: (1) Mix polyvinyl alcohol resin emulsion, polyurethane emulsion and crosslinking agent, and crosslink at 20-50 degrees Celsius under stirring to form a PVA-PU mixed emulsion with an interpenetrating network structure; (2) Add the water-reducing agent to the water, then add the inorganic nanoparticle powder and graphite, and ultrasonically disperse them evenly to obtain a suspension solution; (3) Stir and mix silicate cement with the PVA-PU mixed emulsion in step (1), and then add the suspension solution in step (2); (4) Add quartz sand while stirring and mechanically stir to form a uniform mortar.

2. The aging-resistant polymer repair mortar according to claim 1, characterized in that, Includes the following components by mass: 15 parts of silicate cement; 28 parts of quartz sand; 3 parts of polyvinyl alcohol resin emulsion; 2 parts polyurethane emulsion; Crosslinking agent 0.2 parts; 1.5 parts of inorganic nanoparticle powder; 1.5 parts graphite; 0.08 parts water-reducing agent; 25 parts water.

3. The aging-resistant polymer repair mortar according to claim 1, characterized in that, The particle size of the quartz sand is 20-80 mesh.

4. The aging-resistant polymer repair mortar according to claim 1, characterized in that, In the polyvinyl alcohol resin emulsion, the mass percentage of polyvinyl alcohol resin is 15-30%, the mass percentage of cationic emulsifier is 5-8%, and the remainder is water.

5. The aging-resistant polymer repair mortar according to claim 4, characterized in that, The cationic emulsifier is an alkyl quaternary ammonium salt emulsifier.

6. The aging-resistant polymer repair mortar according to claim 1, characterized in that, In the polyurethane emulsion, the mass percentage of polyurethane resin is 30-50%, the mass percentage of dispersant is 3-5%, the mass percentage of stabilizer is 2-6%, and the remainder is water.

7. The aging-resistant polymer repair mortar according to claim 6, characterized in that, The dispersant is a polyoxyethylene alkylphenol ether or a polyoxyethylene fatty alcohol ether.

8. The aging-resistant polymer repair mortar according to claim 6, characterized in that, The stabilizer is any one or a combination of two or more of dilauryl thiodipropionate, Tinuvin 770, Tinuvin 327, and Tinuvin 328.

9. The aging-resistant polymer repair mortar according to claim 1, characterized in that, The inorganic nanoparticle powder is any one or a combination of two or more of silicon dioxide, aluminum oxide, and magnesium oxide.

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