Plastic steel material for sheet piles and method for producing the same

Abstract

This application provides a plastic-steel material for sheet piles, comprising a main body plate and an adsorption membrane layer. The adsorption membrane layer is a gel elastic membrane layer attached to the main body plate. By weight, the adsorption membrane layer comprises 20 parts polyvinyl chloride, 20 to 30 parts chitosan, 20 to 30 parts polyacrylamide, 10 to 30 parts plasticizer, 5 to 10 parts heat stabilizer, 0.01 to 1 part antioxidant, and 1 to 10 parts antifungal agent. Preferably, it also contains graphene oxide, with a weight percentage of graphene oxide of 0.1% to 0.5%. On one hand, the material prepared by this invention can be used in riverbank sheet pile structures, fixedly installed on both sides of a river. On the other hand, the adsorption membrane layer, obtained through a polymerization reaction, is attached to the riverbank sheet pile structure for installation on both sides of a river. The adsorption membrane layer has a porous structure, enabling the adsorption of metal ions in the river water.

Description

Technical Field

[0001] This application relates to the field of sheet pile technology for riverbank protection, specifically to a technology for achieving the adsorption and purification of metallic substances in river water using sheet pile structures. Background Technology

[0002] Riverbank sheet piles are a type of structure used to support riverbanks or embankments. They are typically used to prevent riverbank and soil erosion, while also protecting buildings and infrastructure around the riverbank. Riverbank sheet piles are usually made of steel, wood, concrete, or PVC, and have sufficient strength and stability to resist erosion by water flow and silt.

[0003] These sheet piles are typically installed vertically or at an angle in the soil or riverbed to provide support and stability. They can be used alone or as part of a composite structure, such as in conjunction with retaining walls or other protective structures.

[0004] The design and selection of riverbank sheet piles typically depend on specific geographical and hydrological conditions, as well as the area to be protected. Factors such as river flow velocity, soil conditions, riverbank slope, and anticipated water level changes must be considered when designing and installing riverbank sheet piles.

[0005] Traditional sheet piles used on riverbanks were made of metal. However, to save costs and with the rapid development and improvement of polymer plastics, many places have replaced them with plastic-steel sheet piles. These plastic-steel sheet piles are usually made of polyvinyl chloride and contain additives such as heat stabilizers and anti-mildew agents.

[0006] Furthermore, many rivers currently suffer from excessive levels of heavy metal ions, and purifying these ions is extremely costly. The installation of sheet pile structures isolates the river, making access difficult for personnel. Moreover, the continuous discharge of wastewater containing heavy metal ions into the rivers necessitates the establishment of a long-term mechanism for the removal of these ions, inevitably leading to persistent heavy metal ion contamination in the rivers. Summary of the Invention

[0007] To address the aforementioned problems, this application proposes a technology that can adsorb heavy metal ions in polluted river water to reduce the degree of pollution and has a long-lasting adsorption effect.

[0008] The present invention first provides a plastic steel material for sheet piles, which includes a main plate and an adsorption membrane layer. The adsorption membrane layer is a gel elastic membrane layer and is attached to the main plate. By weight, the adsorption membrane layer includes 20 parts of polyvinyl chloride, 20 to 30 parts of chitosan, 20 to 30 parts of polyacrylamide, 10 to 30 parts of plasticizer, 5 to 10 parts of heat stabilizer, 0.01 to 1 part of antioxidant, and 1 to 10 parts of mildew inhibitor.

[0009] Preferably, it also contains graphene oxide, wherein the weight percentage of graphene oxide is 0.1% to 0.5%.

[0010] Preferably, the plasticizer is at least one of the following substances: dibutyl phthalate, dioctyl phthalate, epoxidized soybean oil, glyceryl stearate, and diethylmercaptodiphenyltin.

[0011] The antifungal agent is selected from at least one of the following substances: dibutyltin xylene ester, copper amine, and copper acetate;

[0012] The heat stabilizer is selected from at least one of the following substances: tin stearate, tin methyl stearate, tin octoate, and diphenylvinyl dimethyl tin.

[0013] The antioxidant is selected from at least one of the following substances: dimethyl dihydroxyphenol, trimethyl hydroxyphenol, diisopropyl thiophosphate, and triisopropyl phosphate.

[0014] The present invention provides a method for preparing plastic-steel materials for sheet piles, which includes the following preparation steps:

[0015] S1: First, prepare a polyvinyl chloride (PVC) base plastic steel sheet as the main board;

[0016] S2: Vinyl chloride, chitosan monomer, and acrylamide monomer are polymerized under an initiator, with graphene oxide added simultaneously, and the polymerization reaction is carried out under certain temperature and pressure; the adsorption membrane layer includes 20 parts of polyvinyl chloride, 20 to 30 parts of chitosan, 20 to 30 parts of polyacrylamide; 10 to 30 parts of plasticizer, 5 to 10 parts of heat stabilizer, 0.01 to 1 part of antioxidant, and 1 to 10 parts of antifungal agent; it also contains graphene oxide, with the weight percentage of graphene oxide being 0.1% to 0.5%;

[0017] S3: The mixture formed by the reaction is heated, melted, extruded and cooled to form an adsorption film layer. The adsorption film layer is fixed on the polyvinyl chloride base plastic steel board by hot melting or bonding, so that an adsorption film layer is attached to the polyvinyl chloride base plastic steel board.

[0018] Preferably, the preparation method includes the following steps: reacting tri-aminopropyltriethoxysilane with the hydroxyl groups on the graphene oxide in the presence of butylamine and toluene to generate siloxane-bonded graphene; wherein the amount of graphene oxide is 1 part, the volume ratio of butylamine and toluene is 2:1 to 1:2, the total amount of butylamine and toluene is 5 to 20 parts, and the amount of tri-aminopropyltriethoxysilane is 5 to 20 parts.

[0019] Preferably, the initiator is a peroxide initiator or an ionic initiator; the polymerization temperature is room temperature (20°C to 40°C), the polymerization reaction time is 4 to 12 hours, and the polymerization is carried out under neutral pH conditions.

[0020] Preferably, the adsorption film layer is attached to the main body plate by hot melting or bonding.

[0021] Preferably, in the hot-melt method, after the adsorption film is heated to 100°C to 130°C, the adsorption film gradually becomes fluid and then adheres to the main plate. After cooling, a relatively stable adhesion can be achieved.

[0022] Preferably, after a period of use, the membrane material is scraped off from the main body plate, and then a new membrane is reattached to the main body plate to maintain its good adsorption capacity.

[0023] Compared with the prior art, this application has the following beneficial effects: On the one hand, the material prepared by this invention can be used in riverbank sheet pile structures and fixedly installed on both sides of the river; on the other hand, an adsorption membrane layer is obtained through a polymerization reaction, which is attached to the riverbank sheet pile structure for installation on both sides of the river. The adsorption membrane layer has a porous structure, which can be used for the adsorption of metal ions in the river water; furthermore, activated carbon is added to the adsorption membrane layer, and the activated carbon is distributed in the porous structure of the adsorption membrane layer to form a better adsorption effect. Attached Figure Description

[0024] Figure 1 This is a schematic diagram of the application of the plastic steel plate prepared by this invention on one side of a riverbank.

[0025] Figure 2 This is a photograph of the prepared adsorption membrane. Detailed Implementation

[0026] To make the objectives, technical solutions, and advantages of this application clearer, a more detailed description is provided below. However, it should be understood that the description herein is merely for explaining this application and is not intended to limit its scope.

[0027] Example 1

[0028] The PVC-U sheet structure of this embodiment includes a main sheet and an adsorption membrane layer, which is a gel elastic membrane layer. The adsorption membrane layer is attached to the main sheet; by weight, the adsorption membrane layer includes 20 parts of polyvinyl chloride, 20 parts of chitosan, 20 parts of polyacrylamide, 15 parts of plasticizer, 5 parts of heat stabilizer, 0.02 parts of antioxidant, and 1 part of mildew inhibitor.

[0029] This invention also provides a method for preparing a plastic steel material for sheet piles, which includes the following preparation steps:

[0030] S1: First, prepare a polyvinyl chloride (PVC) base plastic steel board as the main board; the PVC base plastic steel board adopts the existing board structure made of PVC material, which will not be described in detail here.

[0031] S2: Vinyl chloride, chitosan monomer, and acrylamide monomer are polymerized under an initiator, with graphene oxide added simultaneously. The polymerization reaction is carried out under certain temperature and pressure conditions. Specifically, benzoyl peroxide initiator is selected; the polymerization temperature is room temperature (25°C), and the polymerization reaction time is 6 hours; polymerization is carried out under neutral pH conditions.

[0032] S3: After the polymerization reaction, the resulting mixture is heated, melted, extruded, and cooled to form an adsorption film. This adsorption film is fixed to the PVC-based plastic steel sheet by heat melting or bonding, thus attaching an adsorption film layer to the PVC-based plastic steel sheet. Chitosan and polyacrylamide are materials with a molecular weight of 10,000 to 50,000. The adsorption film layer is specifically as follows... Figure 2 As shown, a thin, transparent film structure was obtained.

[0033] A unique membrane material is formed through the polymerization of vinyl chloride, chitosan monomers, and acrylamide monomers. The polyvinyl chloride component formed from polyethylene has properties similar to the host plate, resulting in a tight bond that is not easily separated. Chitosan possesses hydrogel properties, giving the adsorption membrane an elastic adsorption state, thus exhibiting excellent adsorption effects for metal ions in water. Furthermore, polyacrylamide also has excellent hydrophilicity and stability, ensuring stable adsorption membrane performance and enabling tight adsorption of metal ions in water to achieve purification.

[0034] The thickness of the membrane material is preferably 0.1 mm to 1 mm.

[0035] Example 2

[0036] The adsorption membrane layer in this embodiment includes 20 parts of polyvinyl chloride, 25 parts of chitosan, 25 parts of polyacrylamide, 15 parts of plasticizer, 5 parts of heat stabilizer, 0.02 parts of antioxidant, and 1 part of antifungal agent.

[0037] Example 3

[0038] The adsorption membrane layer in this embodiment includes 20 parts of polyvinyl chloride, 30 parts of chitosan, 30 parts of polyacrylamide, 15 parts of plasticizer, 5 parts of heat stabilizer, 0.02 parts of antioxidant, and 1 part of antifungal agent.

[0039] Example 4

[0040] The adsorption membrane layer in this embodiment includes 20 parts of polyvinyl chloride, 25 parts of chitosan, 25 parts of polyacrylamide, 15 parts of plasticizer, 5 parts of heat stabilizer, 0.02 parts of antioxidant, and 1 part of antifungal agent.

[0041] Example 5

[0042] The adsorption membrane layer in this embodiment includes 20 parts of polyvinyl chloride, 30 parts of chitosan, 30 parts of polyacrylamide, 15 parts of plasticizer, 5 parts of heat stabilizer, 0.02 parts of antioxidant, and 1 part of antifungal agent.

[0043] Example 6

[0044] The adsorption membrane layer in this embodiment includes 20 parts of polyvinyl chloride, 25 parts of chitosan, 25 parts of polyacrylamide, 15 parts of plasticizer, 5 parts of heat stabilizer, 0.02 parts of antioxidant, and 1 part of antifungal agent.

[0045] Example 7

[0046] The adsorption membrane layer of this embodiment includes 20 parts of polyvinyl chloride, 25 parts of chitosan, 25 parts of polyacrylamide, 15 parts of plasticizer, 5 parts of heat stabilizer, 0.02 parts of antioxidant and 1 part of antifungal agent; and also contains graphene oxide, with the weight percentage of graphene oxide being 0.3%.

[0047] Graphene oxide is a Sigma reagent, chemical substance number: 329768525.

[0048] Experimental Example 1

[0049] The adsorption membranes prepared through the above embodiments are bonded to a main body plate to obtain a sheet pile structure. This sheet pile structure is then applied to both sides of a riverbank for river water isolation and protection. That is, as... Figure 1 The application status is shown.

[0050] Experimental Example 2

[0051] The adsorption effect of the sheet pile structure prepared from the material obtained in Example 1 of the present invention on heavy metal ions in river water was tested. The specific experimental process is as follows:

[0052] The adsorbent on the membrane layer was scraped off over different time periods, such as 2, 4, 6, or more days. It should be noted that the heavy metals adsorbed in each sample are cumulative, and at least three sampling sites were used each time. Each sampling involved taking a sample from a test tube containing a portion of the adsorbent close to the surface of the sheet pile structure; the average value of the three sampling sites was then calculated. The adsorbent (mainly sludge containing heavy metal ions) was dissolved in clean water at a fixed weight ratio, stirred thoroughly, and then the concentration of heavy metals was measured and recorded using an instrument.

[0053] Control group: The control group uses the existing polyvinyl chloride sheet pile structure (i.e., the main plate), which differs from the present invention in that it does not have an adsorption membrane layer.

[0054] Table 1 below is a statistical table showing the time-varying amount of heavy metal ions adsorbed by the sludge adsorbed by the plastic steel sheet of the present invention in riverbank applications.

[0055]

[0056] Table 1

[0057] As can be seen from Table 1, the concentrations of the three typical heavy metal ions Hg, Gr and Pb gradually increased with the increase of the number of days as the soil deposited on the sheet pile structure, and reached their maximum concentration after 10 days. This is because when the sludge adsorbent on the sheet pile structure reaches a certain thickness, the sludge adsorbent needs to be scraped off, otherwise the adsorption force of the surface adsorption film layer of the sheet pile structure will be isolated from the water, which is not conducive to adsorption.

[0058] In the control group, the concentrations of the three typical heavy metal ions Hg, Gr and Pb deposited on the sheet pile structure increased very slowly with the increase of days, and the concentrations were significantly lower than those in the corresponding days of the embodiment of the present invention. This indicates that the surface of the sheet pile structure material of the present invention has an adsorption or adhesion effect on these heavy metal ions, and can be used to purify river sewage.

[0059] Test Example 4

[0060] Following the same method described above, the sheet piles with adsorption membranes prepared from the materials of Example 7 were used to test the heavy metal adsorption performance.

[0061] Table 2 below shows the adsorption statistics of heavy metal ions by different groups after incorporation of silicon-oxygen bonded graphene according to the present invention:

[0062]

[0063] Table 2

[0064] For specific data, please refer to Table 2. The sheet pile structure has a faster adsorption rate for heavy metal ions and an enhanced overall adsorption performance. This indicates that the introduction of modified graphene oxide improves the adsorption capacity of the material for heavy metal ions in Hanoi.

[0065] Table 3 below is a statistical table of test data for the conventional properties of the plastic steel plate structure of the present invention:

[0066]

[0067] Table 3

[0068] Performance testing: The sheet pile structure obtained in Example 1 was subjected to performance testing. The results are shown in Table 3. The density of the sheet pile structure is 1.5 g / cm³, the tensile strength is 75 MPa, and the flexural strength is 70 MPa. These all meet the relevant standards and can be used for riverbank sheet pile structures.

[0069] After a period of use, the membrane material can be scraped off the main board and a new membrane can be reattached to maintain its good adsorption capacity. Alternatively, if the membrane is damaged after prolonged use, it can be replaced. The adsorption membrane is typically attached to the main board using either hot-melt or adhesive methods. In hot-melt methods, the adsorption membrane is heated to 100°C to 130°C, gradually reaching a fluid state before adhering to the main board (PVC board). After cooling, a relatively stable adhesion is achieved. Alternatively, water can be applied to the main board to bond and fix the adsorption membrane.

[0070] The polymer in this invention has three polymerizable monomers: polyvinyl chloride, chitosan, and polyacrylamide. The application of polyvinyl chloride is beneficial for the tight bonding between the adsorption membrane and the main plate after hot melting. Through comparison of experimental data, when polyvinyl chloride is not used, the tightness of the adsorption membrane and the main plate decreases, that is, the adsorption membrane is prone to detachment from the main plate, especially when used for adsorption of metal ions in river water, the adsorption membrane is prone to detachment (including local peeling).

[0071] Chitosan contains numerous functional groups such as amino (-NH2) and hydroxyl (-OH), which can form electrostatic interactions with metal ions, attracting them to adsorb onto the chitosan surface. Polyacrylamide, with its unique carbonyl group (-CONH2), can also attract metal ions to adsorb onto the chitosan surface. These groups have different adsorption capacities for different metal ions, thus their combined use results in better adsorption performance. Furthermore, without polyacrylamide, film formation is poor, meaning the resulting adsorbed film thickness is uneven and prone to wrinkles, localized protrusions, and shrinkage. Using polyacrylamide, however, results in a film with good extensibility, smoothness, and stable performance.

[0072] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the scope of this application. All reagents and instruments used herein are commercially available, and the characterization methods involved can be found in relevant descriptions in the prior art, and will not be repeated here.

[0073] To further understand this application, the following detailed description is provided in conjunction with the preferred embodiments.

[0074] The above description is merely a preferred embodiment of this application and is not intended to limit this application. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A plastic-steel material for sheet piles, characterized in that: The product comprises a main body panel made of polyvinyl chloride (PVC) base plastic steel and an adsorption membrane layer. The adsorption membrane layer is a gel elastic membrane layer attached to the main body panel. By weight, the adsorption membrane layer is prepared by polymerization of vinyl chloride, chitosan monomer, and acrylamide monomer under an initiator and at specific temperature and pressure. It includes 20 parts PVC, 20 to 30 parts chitosan, 20 to 30 parts polyacrylamide, 10 to 30 parts plasticizer, and 5 to 10 parts heat stabilizer. The composition includes 0.01 to 1 part antioxidant and 1 to 10 parts antifungal agent, and also contains graphene oxide, with the graphene oxide accounting for 0.1% to 0.5% by weight. The adsorption membrane and the main plate are tightly bonded due to the presence of polyvinyl chloride. The adsorption membrane is a gel elastic membrane with a porous structure and a thickness of 0.1 mm to 1 mm. It can adsorb heavy metal ions such as Hg, Cr, and Pb in river water, and the adsorption membrane can be scraped off from the main plate and reattached.

2. The plastic-steel material for sheet piles according to claim 1, characterized in that: The plasticizer is at least one of the following substances: dibutyl phthalate, dioctyl phthalate, epoxidized soybean oil, glyceryl stearate, and diethylmercaptodiphenyltin. The antifungal agent is selected from at least one of the following substances: dibutyltin xylene ester, copper amine, and copper acetate; The heat stabilizer is selected from at least one of the following substances: tin stearate, tin methyl stearate, tin octoate, and diphenylvinyl dimethyl tin. The antioxidant is selected from at least one of the following substances: dimethyldihydroxyphenol, trimethylhydroxyphenol, diisopropyl thiophosphate, and triisopropyl phosphate.

3. The method of producing a plastic-steel material for sheet piles according to claim 1, characterized in that: The preparation steps include the following: S1: First, prepare a polyvinyl chloride (PVC) base plastic steel sheet as the main board; S2: A mixture of vinyl chloride, chitosan monomer and acrylamide monomer is polymerized under an initiator and subjected to a polymerization reaction at a certain temperature and pressure to obtain an adsorption membrane layer. The adsorption membrane layer includes 20 parts of polyvinyl chloride, 20 to 30 parts of chitosan and 20 to 30 parts of polyacrylamide. The composition includes 10 to 30 parts plasticizer, 5 to 10 parts heat stabilizer, 0.01 to 1 part antioxidant, and 1 to 10 parts mildew inhibitor. S3: The mixture formed by the reaction is heated, melted, extruded and cooled to form an adsorption film. The adsorption film is fixed to the PVC base plastic steel board by hot melting or bonding, so that an adsorption film is attached to the PVC base plastic steel board. The adsorption film is a gel elastic film with a porous structure and a thickness of 0.1 mm to 1 mm. It can achieve efficient adsorption of Hg, Cr and Pb heavy metal ions in river water. The adsorption film material can be scraped off from the main board and then a new film can be reattached to the main board to maintain its good adsorption capacity. In S2, graphene oxide is also added, with the weight percentage of graphene oxide being 0.1% to 0.5%.

4. The method of producing a plastic-steel material for sheet piles according to claim 3, characterized in that: Peroxide initiators or ionic initiators are selected; the polymerization temperature is room temperature (20℃ to 40℃), and the polymerization reaction time is 4 to 12 hours; polymerization is carried out under neutral pH conditions.

5. The method of producing a plastic-steel material for sheet piles according to claim 3, characterized in that: The adsorption film layer is attached to the main board by means of hot melting or bonding.

6. The method for preparing plastic-steel material for sheet piles according to claim 3, characterized in that: In the hot-melt method, after the adsorption film is heated to 100°C to 130°C, the adsorption film gradually becomes fluid and then adheres to the main plate. After cooling, a relatively stable adhesion can be achieved.

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