Composition for preparing anticorrosive ALC board and preparation method

Abstract

This invention provides a composition for preparing anti-corrosion ALC panels, comprising, by weight, 5-40 parts of fly ash and / or silica sand, 5-20 parts of cement, 10-20 parts of lime, and 20-40 parts of filler; wherein the filler comprises graphene oxide, sodium polyacrylate, and modified nano zinc oxide in a mass ratio of 1-3:1:1-2; wherein the graphene oxide is pre-modified by a silane coupling agent; it has excellent anti-corrosion properties, not only providing long-term anti-corrosion effects but also exhibiting excellent high-temperature corrosion resistance; a method for preparing the above composition is also provided, so that after being added to the panel, it continues to exert its anti-corrosion effect over time.

Description

Technical Field

[0001] This invention relates to the field of building materials technology, and more specifically, to a composition and preparation method for preparing anti-corrosion ALC boards. Background Technology

[0002] ALC is short for Autoclaved Lightweight Concrete, a type of high-performance autoclaved aerated concrete (ALC). ALC panels are porous concrete slabs (containing treated steel reinforcement) made primarily from fly ash (or silica sand), cement, and lime, cured under high-pressure steam. ALC panels can be used as wall materials or roofing panels, making them a high-performance new building material. This material not only has good thermal insulation properties [λ=0.13W / (m·K)], but also excellent heat insulation properties [heat storage coefficient S=2.75W / (m2·K)]. When an appropriate thickness is used, it can be used not only in cold regions with high insulation requirements, but also in hot-summer-cold-winter regions or hot-summer-warm-winter regions with high heat insulation requirements, meeting energy-saving standards.

[0003] However, due to unreasonable raw material composition and proportions, and outdated production processes, existing ALC panels have poor corrosion resistance. As a result, during use, ALC panels are inevitably corroded by factors such as weather, leading to cracks. Special ALC panel repair mortar is used to repair and fill the cracks. Most existing ALC panel repair mortars are composed of cement, quartz sand, and polymer binders. When repairing ALC panels, they not only have poor bonding effects but also cannot provide long-term corrosion protection, causing the ALC panels to crack again due to corrosion and affecting their performance. Summary of the Invention

[0004] The first objective of this invention is to provide a composition for preparing anti-corrosion ALC plates, which has excellent anti-corrosion properties, not only having a long-term anti-corrosion effect, but also excellent high-temperature corrosion resistance.

[0005] A second objective of this invention is to provide a method for preparing the above-mentioned composition, so that when added to a board, it can continue to exert its anti-corrosion effect over time.

[0006] The embodiments of the present invention are achieved through the following technical solutions:

[0007] A composition for preparing anti-corrosion ALC plates, comprising, by weight, 5-40 parts of fly ash and / or silica sand, 5-20 parts of cement, 10-20 parts of lime, and 20-40 parts of filler; wherein the filler comprises graphene oxide, sodium polyacrylate, and modified nano zinc oxide in a mass ratio of 1-3:1:1-2; wherein the graphene oxide is pre-modified by a silane coupling agent.

[0008] A method for preparing a composition for making anti-corrosion ALC plates includes the following steps:

[0009] S1. First, mix fly ash and / or silica sand and cement evenly, and add some graphene oxide and sodium polyacrylate to obtain a mixed liquid.

[0010] S2. Add a portion of the modified nano zinc oxide and lime to water and mix well to obtain mixture two;

[0011] S3. Mix mixture one and mixture two thoroughly, then add the remaining graphene oxide, sodium polyacrylate and modified nano zinc oxide, mix thoroughly, and the preparation is complete.

[0012] The technical solutions of the embodiments of the present invention have at least the following advantages and beneficial effects:

[0013] 1. The present invention relates to a composition for preparing anti-corrosion ALC boards. After functionalizing graphene oxide with sodium polyacrylate, the other components of graphene oxide have better compatibility and form a denser coating to achieve water-based anti-corrosion capability, thereby significantly reducing the corrosion density of the board and effectively improving the protection capability of the board.

[0014] 2. The composition of the present invention for preparing anti-corrosion ALC board, by modifying the nano zinc oxide particles with modified calcium lignosulfonate and calcium alginate, can effectively prevent the invasion of foreign ions. Even if metal ions invade, the chelating properties of modified calcium lignosulfonate can be used to prevent external metal ions from corroding the board, thus achieving a good anti-corrosion effect from both prevention and chelation aspects.

[0015] 3. The present invention relates to a composition for preparing anti-corrosion ALC plates. The modified nano zinc oxide particles can fully utilize the advantages of small size and surface effect of nano zinc oxide particles, so that they have better dispersibility after being combined with graphene oxide in the system, are not easy to agglomerate, and can form smaller porosity, thereby improving the compatibility and compactness between the base material and the plate, thus forming a more dense and solid coating that can effectively delay the penetration of corrosive media into the plate, and significantly improving the hydrophobicity of the plate surface.

[0016] 4. In the preparation process of the composition of the present invention, different fillers are added in stages and an appropriate amount of base material is added. This can improve the dispersibility of the fillers and the concentration gradient in the system, so that the fillers can continue to play an anti-corrosion role as the service time goes by. Detailed Implementation

[0017] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below. Where specific conditions are not specified in the embodiments, conventional conditions or conditions recommended by the manufacturer shall apply. Reagents or instruments whose manufacturers are not specified are all conventional products that can be purchased commercially.

[0018] The following is a detailed description of a composition and preparation method for preparing anti-corrosion ALC plates provided by embodiments of the present invention.

[0019] A composition for preparing anti-corrosion ALC plates, comprising, by weight, 5-40 parts of fly ash and / or silica sand, 5-20 parts of cement, 10-20 parts of lime and 20-40 parts of filler;

[0020] The filler comprises graphene oxide and sodium polyacrylate, and modified nano zinc oxide in a mass ratio of 1-3:1:1-2; the filler also includes appropriate amounts of water-reducing agent, foaming agent, retarder, thickener, etc.

[0021] Modified nano zinc oxide is modified by modifying calcium lignosulfonate and calcium alginate; wherein, the modified calcium lignosulfonate is pre-modified by grafting carboxyl groups.

[0022] Graphene oxide is pre-modified with a silane coupling agent. The modification technology is existing and will not be elaborated on in detail. By modifying it, graphene oxide has good dispersibility and is more uniformly dispersed in the slurry. More importantly, it lays a good foundation for the combination with other fillers.

[0023] Specifically, the preparation method of modified calcium lignosulfonate is as follows: calcium lignosulfonate is dissolved in an acidic aqueous solution, and then hydroxymethylacrylamide solution and peroxide initiator are added dropwise. After the addition is completed, the mixture is kept at a constant temperature for a period of time to obtain modified calcium lignosulfonate. The mass ratio of calcium lignosulfonate, hydroxymethylacrylamide and peroxide initiator is 2-5:1-3:1.

[0024] The modified nano-zinc oxide is prepared as follows: Sodium thiosulfate, 1 / 3 mass of modified calcium lignosulfonate, 1 / 3 mass of calcium alginate solution, and 1 / 3 mass of nano-zinc oxide are added to an alcohol solvent. An appropriate amount of silane coupling agent is then added. The solution is reacted at a certain temperature of 40-50℃ for a period of time, then cooled to room temperature. The remaining modified calcium lignosulfonate, calcium alginate solution, and nano-zinc oxide are added again, and the mixture is dispersed at high speed to obtain the modified nano-zinc oxide. The mass ratio of sodium thiosulfate, modified calcium lignosulfonate, calcium alginate solution, and nano-zinc oxide is 1:1-2:1-2:2-5.

[0025] In particular, the modification of graphene oxide with sodium polyacrylate allows the modified graphene oxide to be functionalized through both covalent and non-covalent bond modifications. This enables better compatibility between the modified graphene oxide and the modified nano zinc oxide, forming a denser coating that achieves water-based anti-corrosion capabilities. This significantly reduces the corrosion density of the board and effectively enhances its protective ability.

[0026] The combination of nano-zinc oxide particles and modified graphene oxide allows the nano-zinc oxide particles to be stably dispersed in the system. Furthermore, by modifying the nano-zinc oxide particles with calcium lignosulfonate and calcium alginate, more groups such as carboxyl and sulfate groups are introduced. In particular, the introduction of carboxyl and amide groups can cross-link with the dispersed structure of graphene oxide to form a dense polymer structure, thereby forming a dense film that prevents the erosion of external ions. Even if metal ions invade, the chelating properties of modified calcium lignosulfonate can be used to prevent external metal ions from corroding the board. Thus, it achieves a good anti-corrosion effect from both prevention and chelation aspects.

[0027] More importantly, the modified nano zinc oxide particles can fully utilize the advantages of small size and surface effect, making them more dispersed in the system, less prone to agglomeration, and able to form smaller porosity. This improves the compatibility and compactness between the base material and the plate, resulting in a more dense and solid coating that can effectively delay the penetration of corrosive media into the plate and significantly improve the hydrophobicity of the plate surface.

[0028] A method for preparing a composition for making anti-corrosion ALC plates includes the following steps:

[0029] S1. First, mix fly ash and / or silica sand and cement evenly, and add 1 / 3 part by weight of graphene oxide and 1 / 3 part by weight of sodium polyacrylate to obtain a mixture.

[0030] S2. Add 1 / 3 part by weight of modified nano zinc oxide and lime to water and mix well to obtain mixture two;

[0031] S3. Mix mixture one and mixture two thoroughly, then add the remaining graphene oxide, sodium polyacrylate and modified nano zinc oxide, mix thoroughly, and the preparation is complete.

[0032] In the preparation process of this invention, different fillers are added in stages and combined with an appropriate amount of base material. This improves the dispersibility of the fillers and the concentration gradient in the system, so that the fillers can continue to play an anti-corrosion role over time during use.

[0033] Example 1

[0034] The composition used to prepare anti-corrosion ALC board comprises, by weight, 100g of fly ash, 100g of cement, 150g of lime and 300g of filler, and 20g of polycarboxylate superplasticizer, 20g of plant-derived composite foaming agent, 20g of protein retarder and 20g of hydroxypropyl methylcellulose thickener.

[0035] The filler comprises 120g of graphene oxide, 60g of sodium polyacrylate, and 120g of modified nano zinc oxide.

[0036] The modified nano zinc oxide is prepared as follows: 10 parts sodium thiosulfate, 5 parts modified calcium lignosulfonate, 5 parts calcium alginate solution and 10 parts nano zinc oxide are added to an ethanol solvent, and an appropriate amount of silane coupling agent is added. The solution is reacted at 40-50℃ for a period of time and then cooled to room temperature. The remaining 10 parts modified calcium lignosulfonate, 10 parts calcium alginate solution and 20 parts nano zinc oxide are added again. After high-speed dispersion, the modified nano zinc oxide is obtained.

[0037] The preparation method of modified calcium lignosulfonate is as follows: In a three-necked flask equipped with a stirrer and a dropping funnel, 40g of calcium lignosulfonate is dissolved in an acidic aqueous solution, and 20g of hydroxymethylacrylamide solution and 10g of hydrogen peroxide and benzoyl peroxide are added dropwise. The synthesis experiment is carried out according to the free radical reaction. After the solution is added dropwise, the temperature is kept constant at 60℃ for 1 hour to obtain modified calcium lignosulfonate.

[0038] A method for preparing a composition for preparing an anti-corrosion ALC board includes the following steps:

[0039] S1. First, mix fly ash and / or silica sand and cement evenly, and add 40g of graphene oxide and 20g of sodium polyacrylate to obtain a mixed liquid.

[0040] S2. Add 40g of modified nano zinc oxide and lime to water and mix well to obtain mixture two;

[0041] S3. Mix mixture one and mixture two thoroughly, then add the remaining graphene oxide, sodium polyacrylate and modified nano zinc oxide, mix thoroughly, and the preparation is complete.

[0042] Example 2

[0043] The difference between this embodiment and Embodiment 1 is that the composition used to prepare the anti-corrosion ALC plate includes, by weight, 200g of silica sand, 200g of cement, 200g of lime and 400g of filler; wherein the filler includes 200g of graphene oxide, 10g of sodium polyacrylate and 100g of modified nano zinc oxide.

[0044] Example 3

[0045] The difference between this embodiment and Embodiment 1 is that the composition used to prepare the anti-corrosion ALC board, by weight, includes 80g of silica sand, 90g of cement, 120g of lime and 240g of filler; wherein the filler includes 120g of graphene oxide, 60g of sodium polyacrylate and 60g of modified nano zinc oxide.

[0046] Example 4

[0047] The difference between this embodiment and Embodiment 1 is that the composition used to prepare the anti-corrosion ALC board, by weight, includes 200g of fly ash, 200g of silica sand, 200g of cement, 200g of lime and 400g of filler; wherein the filler includes 200g of graphene oxide, 100g of sodium polyacrylate and 100g of modified nano zinc oxide.

[0048] Comparative Example 1

[0049] The difference between this comparative example and Example 1 is that the composition used to prepare the anti-corrosion ALC board includes 100g of fly ash, 100g of cement, 150g of lime and 100g of filler, wherein the filler includes 50g of graphene oxide, 25g of sodium polyacrylate and 25g of modified nano zinc oxide.

[0050] Comparative Example 2

[0051] The difference between this comparative example and Example 1 is that the composition used to prepare the anti-corrosion ALC plate does not include graphene oxide.

[0052] Comparative Example 3

[0053] The difference between this comparative example and Example 1 is that the nano zinc oxide in the composition used to prepare the anti-corrosion ALC plate was not modified.

[0054] Comparative Example 4

[0055] The difference between this comparative example and Example 1 is that the modified nano zinc oxide in the composition used to prepare the anti-corrosion ALC board is modified by calcium lignosulfonate and calcium alginate; that is, the calcium lignosulfonate is not modified.

[0056] Experimental Example 1

[0057] The slurries from Examples 1-4 and Comparative Examples 1-4 were placed into molds to form sheets. Specifically, ALC sheets can be prepared by the following method: assembling the reinforcing mesh into the mold; pouring the slurries from Examples 1-4 and Comparative Examples 1-4 into the mold; static curing to allow the slurry to solidify and form a preform; demolding and cutting the preform; steam curing; and finishing. The above methods are existing technologies and will not be elaborated further.

[0058] The above-mentioned plates were immersed in a 15% hydrochloric acid solution at 60°C to examine the degree of corrosion at different times. In addition, an accelerated test was conducted by immersing the plates in a 15% hydrochloric acid solution at 150°C. The results are shown in Table 1.

[0059] Table 1 Performance results of different sheet materials

[0060]

[0061]

[0062] As shown in Table 1, the ALC board prepared using the slurry composition of the present invention has excellent anti-corrosion properties, not only with long-term anti-corrosion effect, but also with excellent high-temperature corrosion resistance.

[0063] The weight percentages of each component in the composition of Comparative Example 1 are outside the scope of the compositions of this invention. The composition of Comparative Example 2 does not include graphene oxide, and the ALC boards prepared from it have poor anti-corrosion performance, exhibiting severe corrosion after 6 months. Furthermore, its corrosion performance is poor at high temperatures, resulting in severe corrosion. The composition of Comparative Example 3, in which nano-zinc oxide was not modified, produced the ALC boards with the worst anti-corrosion performance. This is mainly because the lack of modification treatment of the nano-zinc oxide prevents the full utilization of the advantages of its small size and surface effect. The nano-zinc oxide particles exhibit poor dispersibility and are prone to aggregation in the system, resulting in poor compatibility with the board material and an inability to form a good dense structural layer, making it easy for corrosive media to penetrate the board. The composition of Comparative Example 4, in which calcium lignosulfonate was not modified, produced ALC boards with very poor anti-corrosion performance. This is mainly because it cannot effectively prevent the erosion of external ions or chelate invading ions, thus failing to achieve a good anti-corrosion effect.

[0064] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A composition for preparing anti-corrosion ALC panels, characterized in that, Includes fly ash and / or silica sand, cement, lime, and fillers, wherein the fillers include graphene oxide, sodium polyacrylate, and modified nano zinc oxide; The composition comprises, by weight, 5-40 parts of fly ash and / or silica sand, 5-20 parts of cement, 10-20 parts of lime and 20-40 parts of filler; wherein the filler comprises graphene oxide, sodium polyacrylate and modified nano zinc oxide in a mass ratio of 1-3:1:1-2. The modified nano zinc oxide is modified by calcium lignosulfonate and calcium alginate. The modified calcium lignosulfonate is prepared as follows: calcium lignosulfonate is dissolved in an acidic aqueous solution, and then hydroxymethylacrylamide solution and peroxide initiator are added dropwise. After the addition is completed, the mixture is kept at a constant temperature for a period of time to obtain the modified calcium lignosulfonate. The modified nano zinc oxide is prepared as follows: (1) Add sodium thiosulfate, partially modified calcium lignosulfonate, partially calcium alginate solution and partially nano zinc oxide to alcohol solvent, and then add an appropriate amount of silane coupling agent. After reacting the solution at a certain temperature for a period of time, cool it to room temperature. (2) Add the remaining modified calcium lignosulfonate solution, calcium alginate solution and nano zinc oxide again, and disperse at high speed to obtain modified nano zinc oxide.

2. The composition for preparing anti-corrosion ALC plates according to claim 1, characterized in that, The graphene oxide was modified in advance using a silane coupling agent.

3. The composition for preparing anti-corrosion ALC plates according to claim 1, characterized in that, The mass ratio of calcium lignosulfonate, hydroxymethylacrylamide, and peroxide initiator is 2-5:1-3:

1.

4. The composition for preparing anti-corrosion ALC plates according to claim 1, characterized in that, The mass ratio of sodium thiosulfate, modified calcium lignin sulfonate, calcium alginate solution, and nano zinc oxide is 1:1-2:1-2:2-5.

5. The composition for preparing anti-corrosion ALC plates according to claim 1, characterized in that, In step (1), 1 / 3 mass of modified calcium lignin sulfonate, 1 / 3 mass of calcium alginate solution and 1 / 3 mass of nano zinc oxide are added first.

6. A method for preparing a composition for preparing an anti-corrosion ALC board according to any one of claims 1-5, characterized in that, Includes the following steps: S1. First, mix fly ash and / or silica sand and cement evenly, and add some graphene oxide and sodium polyacrylate to obtain a mixed liquid. S2. Add a portion of the modified nano zinc oxide and lime to water and mix well to obtain mixture two; S3. Mix mixture one and mixture two thoroughly, then add the remaining graphene oxide, sodium polyacrylate and modified nano zinc oxide, mix thoroughly, and the preparation is complete.

7. The method for preparing the composition for preparing anti-corrosion ALC plates according to claim 6, characterized in that, S1 contains 1 / 3 part by weight of graphene oxide and 1 / 3 part by weight of sodium polyacrylate; S2 contains 1 / 3 part by weight of modified nano zinc oxide.

Images