High-weather-resistance composite geomembrane and preparation method thereof
By introducing alkenyl-grafted titanium dioxide and fluorine-containing hindered amine compounds into the geomembrane, the problem of poor weather resistance of polypropylene geomembrane was solved, and the high weather-resistant composite geomembrane was improved in terms of UV aging resistance and mechanical properties, thus extending its service life.
Patent Information
- Application Number
- CN202511988227.6
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-12-26
- Publication Date
- 2026-02-24
AI Technical Summary
Traditional polypropylene geomembranes have poor weather resistance and are easily oxidized and degraded by ultraviolet radiation, resulting in decreased tensile strength, brittleness and cracking, short service life, and reduced seepage prevention effect.
A high-weather-resistant composite geomembrane was prepared by combining alkenyl-grafted titanium dioxide and fluorinated hindered amine compounds with polypropylene resin and then melt-extruding it using a twin-screw extruder. The weather resistance and mechanical strength of the geomembrane were improved by utilizing the ultraviolet absorption of titanium dioxide and the free radical scavenging effect of the fluorinated hindered amine compounds.
It significantly improves the UV resistance of geomembranes, enhances their overall mechanical properties and waterproofness, extends their service life, and ensures stability and long-term effectiveness.
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Figure SMS_1
Abstract
Description
Technical Field
[0001] This invention relates to the field of geomembranes, specifically to a high weather-resistant composite geomembrane and its preparation method. Background Technology
[0002] Geomembranes, as an important seepage control material, are widely used in water conservancy, environmental protection, mining, and other fields. Their core function is to prevent liquid seepage and withstand certain mechanical loads. Polypropylene is a commonly used matrix material for geomembranes due to its low cost, excellent mechanical properties, and good processability. However, traditional polypropylene geomembranes have significant drawbacks: polypropylene has poor weather resistance and is easily oxidized and degraded by ultraviolet radiation, causing molecular chain breakage. This leads to a decrease in tensile strength, brittleness, and cracking of polypropylene geomembranes within a short period of use. In areas with strong ultraviolet radiation (such as plateaus and deserts), their service life is short, affecting their seepage control effect.
[0003] Therefore, developing a high weather-resistant composite geomembrane and its preparation method is of great practical significance. Summary of the Invention
[0004] In order to overcome the above-mentioned technical problems, the present invention aims to provide a high weather-resistant composite geomembrane and its preparation method, which solves the problem that the existing polypropylene geomembrane has poor weather resistance, and will experience a decrease in tensile strength and become brittle and cracked in a short period of time during use, resulting in a short service life and affecting the seepage prevention effect.
[0005] The objective of this invention can be achieved through the following technical solutions: In a first aspect, this application provides a high weather-resistant composite geomembrane, comprising the following components in parts by weight: The composition includes 90-95 parts of polypropylene resin, 1-7 parts of alkenyl grafted titanium dioxide, 0.3-1.5 parts of fluorine-containing hindered amine compound, 0.8-1.2 parts of bis-tert-butylperoxyisopropylbenzene, 0.2-0.4 parts of calcium stearate, and 0.1-0.3 parts of erucamide. The alkenyl-grafted coated titanium dioxide is prepared by the following steps: Step a1: Add polyvinylpyrrolidone and cerium nitrate solution to a three-necked flask equipped with a stirrer, thermometer and constant pressure dropping funnel. Stir the reaction for 20-30 min at a temperature of 20-25℃ and a stirring rate of 200-300 r / min. Then, add ammonia water dropwise while stirring, controlling the dropping rate to 1-3 drops / s. After the addition is complete, continue stirring the reaction for 1-2 h to obtain cerium oxide sol. Step a2: Add nano-titanium dioxide and cerium oxide sol to a three-necked flask equipped with a stirrer and thermometer. Stir the reaction at 20-25℃ and 200-300 r / min for 20-30 min. Then adjust the pH to 8.5-9.5 with sodium hydroxide solution. Then raise the temperature to 60-70℃ and continue stirring for 1-3 h. After the reaction is completed, cool the reaction product to room temperature, then centrifuge. Place the precipitate in a vacuum drying oven and dry it at 80-85℃ for 2-3 h to obtain coated titanium dioxide. Step a3: Add anhydrous ethanol and deionized water to a three-necked flask equipped with a stirrer and thermometer. Stir the reaction at 20-25℃ and 200-300 r / min for 3-5 min. Then adjust the pH to 5-6 with glacial acetic acid. Add coated titanium dioxide and silane coupling agent KH-570 and continue stirring for 20-30 min. Then raise the temperature to 80-85℃ and continue stirring for 6-8 h. After the reaction is complete, cool the reaction product to room temperature, centrifuge, and place the precipitate in a vacuum drying oven. Dry it at 80-85℃ for 2-3 h to obtain alkenyl grafted coated titanium dioxide.
[0006] In a preferred embodiment of the present invention, the ratio of polyvinylpyrrolidone, cerium nitrate solution and ammonia in step a1 is 1-1.2g:100mL:2-4mL.
[0007] In a preferred embodiment of the present invention, the polyvinylpyrrolidone in step a1 is PVP K30; the molar concentration of the cerium nitrate solution is 0.05-0.07 mol / L; and the molar concentration of the ammonia water is 2-2.5 mol / L.
[0008] In a preferred embodiment of the present invention, the ratio of nano-titanium dioxide to cerium oxide sol in step a2 is 5g:60-70mL.
[0009] In a preferred embodiment of the present invention, the average particle size of the nano-titanium dioxide in step a2 is 100 nm; and the mass fraction of the sodium hydroxide solution is 20-25%.
[0010] In a preferred embodiment of the present invention, the ratio of anhydrous ethanol, deionized water, coated titanium dioxide and silane coupling agent KH-570 in step a3 is 75-85mL: 10-15mL: 5g: 1-5g.
[0011] In a preferred embodiment of the present invention, the fluorinated hindered amine compound is prepared by the following steps: Step b1: Add cyanuric chloride and toluene to a three-necked flask equipped with a stirrer, thermometer, gas delivery tube, and constant pressure dropping funnel. Purge with nitrogen for protection and stir for 20-30 min at 0-5℃ and 200-300 r / min. Then add N-butyl-2,2,6,6-tetramethyl-4-piperidinamine and continue stirring for 2-3 h. Then add sodium hydroxide solution dropwise while stirring, controlling the dropping rate to 1-3 drops / s. After the addition is complete, raise the temperature to 70-75℃ and continue stirring for 10-15 h. After the reaction is complete, cool the reaction product to room temperature and add it to mixed solvent A. Then allow it to stand and separate into layers. Dry the organic phase with anhydrous magnesium sulfate and then filter under vacuum. Remove the solvent by rotary evaporation of the filtrate to obtain the hindered amine chlorine compound. Step b2: Add bisphenol AF and N,N-dimethylformamide to a three-necked flask equipped with a stirrer and thermometer. Stir the reaction at 20-25℃ and 200-300 r / min for 20-30 min. Then add anhydrous potassium carbonate and toluene and continue stirring for 20-30 min. After that, add the hindered amine chlorine compound and heat to 100-110℃ and continue stirring for 3-5 h. After the reaction is complete, filter the reaction product while it is hot. Pour the filtrate into distilled water and centrifuge. Recrystallize the precipitate with mixed solvent B to obtain the fluorinated hindered amine compound.
[0012] In a preferred embodiment of the present invention, the ratio of cyanuric chloride, toluene, N-butyl-2,2,6,6-tetramethyl-4-piperidinamine and sodium hydroxide solution in step b1 is 10 mmol: 20-30 mL: 20 mmol: 2-4 mL.
[0013] In a preferred embodiment of the present invention, the sodium hydroxide solution in step b1 has a mass fraction of 30-40%; the mixed solvent A is a mixture of deionized water and ethyl acetate in a volume ratio of 2:1.
[0014] In a preferred embodiment of the present invention, the ratio of bisphenol AF, N,N-dimethylformamide, anhydrous potassium carbonate, toluene and hindered amine chlorine compound used in step b2 is 10 mmol: 20-30 mL: 25-30 mmol: 10-12 mL: 20 mmol.
[0015] In a preferred embodiment of the present invention, the mixed solvent B in step b2 is a mixture of N,N-dimethylformamide and ethanol in a volume ratio of 3:1.
[0016] Secondly, this application provides a method for preparing a high weather-resistant composite geomembrane, used to prepare the high weather-resistant composite geomembrane as described in the first aspect, comprising the following steps: Step 1: Weigh out 90-95 parts by weight of polypropylene resin, 1-7 parts by weight of alkenyl grafted titanium dioxide, 0.3-1.5 parts by weight of fluorine-containing hindered amine compound, 0.8-1.2 parts by weight of bis-tert-butylperoxyisopropylbenzene, 0.2-0.4 parts by weight of calcium stearate and 0.1-0.3 parts by weight of erucamide, and set aside; the polypropylene resin is PP L5E89; Step 2: Polypropylene resin, alkenyl grafted titanium dioxide, fluorinated hindered amine compound, bis-tert-butylperoxyisopropylbenzene, calcium stearate and erucamide are added to a twin-screw extruder and melt-extruded at a temperature of 180-200℃ and a screw speed of 80-100 r / min. After casting, a high weather-resistant composite geomembrane is obtained.
[0017] The beneficial effects of this invention are: This invention discloses a high weather-resistant composite geomembrane and its preparation method. The method involves adding polypropylene resin, alkenyl-grafted coated titanium dioxide, fluorinated hindered amine compound, bis(tert-butylperoxyisopropylbenzene), calcium stearate, and erucamide into a twin-screw extruder for melt extrusion, followed by casting to obtain the high weather-resistant composite geomembrane. This geomembrane uses polypropylene as the main raw material, providing excellent mechanical strength and chemical stability. The addition of alkenyl-grafted coated titanium dioxide and fluorinated hindered amine compound significantly improves the geomembrane's resistance to ultraviolet aging, thereby significantly enhancing its weather resistance. Furthermore, it enhances its comprehensive mechanical properties, improves waterproofing and corrosion resistance, and significantly improves the stability and longevity of the geomembrane in practical applications. In the preparation of a high-weather-resistant composite geomembrane, an alkenyl-grafted coated titanium dioxide was first prepared. Nano-titanium dioxide was coated with cerium oxide to obtain coated titanium dioxide. Then, the coated titanium dioxide was modified using a silane coupling agent KH-570. The siloxanes on the silane coupling agent KH-570 hydrolyzed to form silanols, which were then grafted onto the surface of the coated titanium dioxide particles, simultaneously introducing a large number of alkenyl groups, resulting in alkenyl-grafted coated titanium dioxide. Titanium dioxide effectively absorbs UVB ultraviolet radiation, while cerium oxide has good absorption of both UVA and UVB ultraviolet radiation. The combination of the two achieves a full-band ultraviolet shield. Furthermore, the cerium oxide coating on the surface of titanium dioxide, which has high photocatalytic activity, can effectively inhibit the photocatalytic activity of titanium dioxide under ultraviolet light, preventing its catalytic degradation of the polypropylene matrix. After modification, the compatibility of the coated titanium dioxide can be significantly improved, allowing it to be uniformly dispersed in the geomembrane. Moreover, the introduced alkenyl groups are grafted with polypropylene free radicals under the action of bis-tert-butylperoxyisopropylbenzene, forming chemical bonds that improve the mechanical properties of the geomembrane. It can also fundamentally solve the problems of nanoparticle aggregation and migration, ensuring a long-term and stable shielding effect, thereby significantly improving the weather resistance of the geomembrane. In the preparation of high weather-resistant composite geomembranes, a fluorinated hindered amine compound was first prepared. This was achieved through the reaction of cyanuric chloride and N-butyl-2,2,6,6-tetramethyl-4-piperidinamine, where some chlorine atoms on the cyanuric chloride react with the secondary amine group attached to the butyl group on N-butyl-2,2,6,6-tetramethyl-4-piperidinamine, yielding the hindered amine-containing chlorine compound. Then, through the reaction of bisphenol AF and the hindered amine-containing chlorine compound, the hydroxyl groups on bisphenol AF react with the remaining chlorine atoms on the hindered amine-containing chlorine compound, forming a structure containing multiple hindered amine structures and fluorine atoms. The fluorinated hindered amine compound; the synergistic effect of multiple hindered amine structures in the molecular structure of the fluorinated hindered amine compound can continuously and efficiently capture free radicals generated during the aging process of geomembrane, interrupting the chain reaction. The multiple fluorine atoms in its molecular structure can significantly improve the chemical and thermal stability of the geomembrane, making it less prone to decomposition and failure under harsh environments and high temperatures. At the same time, fluorine atoms may also make it tend to migrate and accumulate on the material surface, forming a dynamic protective layer on the surface layer most prone to aging, further improving the weather resistance of the geomembrane. Detailed Implementation
[0018] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.
[0019] Example 1: This example illustrates a method for preparing a high weather-resistant composite geomembrane, comprising the following steps: Step S1: Add 1g of polyvinylpyrrolidone (PVP K30) and 100mL of cerium nitrate solution with a molar concentration of 0.05mol / L to a three-necked flask equipped with a stirrer, thermometer, and constant pressure dropping funnel. Stir the reaction at 20℃ and 200r / min for 20min. Then, while stirring, add 2mL of ammonia solution with a molar concentration of 2mol / L dropwise, controlling the dropping rate to 1 drop / s. After the addition is complete, continue stirring the reaction for 1h to obtain cerium oxide sol. Step S2: Add 5g of nano-titanium dioxide with an average particle size of 100nm and 60mL of cerium oxide sol to a three-necked flask equipped with a stirrer and a thermometer. Stir the reaction at 20℃ and 200r / min for 20min. Then adjust the pH to 8.5 with 20% sodium hydroxide solution. Continue stirring the reaction at 60℃ for 1h. After the reaction is completed, cool the reaction product to room temperature, centrifuge it, and place the precipitate in a vacuum drying oven to dry at 80℃ for 2h to obtain coated titanium dioxide. Step S3: Add 75 mL of anhydrous ethanol and 10 mL of deionized water to a three-necked flask equipped with a stirrer and thermometer. Stir the reaction at 20 °C and 200 r / min for 3 min. Then adjust the pH to 5 with glacial acetic acid. Add 5 g of coated titanium dioxide and 1 g of silane coupling agent KH-570 and continue stirring for 20 min. Then raise the temperature to 80 °C and continue stirring for 6 h. After the reaction is complete, cool the reaction product to room temperature, centrifuge, and place the precipitate in a vacuum drying oven. Dry it at 80 °C for 2 h to obtain alkenyl grafted coated titanium dioxide. Step S4: Add 10 mmol of cyanuric chloride and 20 mL of toluene to a three-necked flask equipped with a stirrer, thermometer, gas delivery tube, and constant pressure dropping funnel. Purge with nitrogen for protection and stir at 0 °C and 200 r / min for 20 min. Then add 20 mmol of N-butyl-2,2,6,6-tetramethyl-4-piperidinamine and continue stirring for 2 h. Then add 2 mL of 30% sodium hydroxide solution dropwise while stirring, controlling the dropping rate to 1 drop / s. After the addition is complete, raise the temperature to 70 °C and continue stirring for 10 h. After the reaction is complete, cool the reaction product to room temperature and add it to a mixed solvent A composed of deionized water and ethyl acetate in a volume ratio of 2:1. After standing and separating the layers, dry the organic phase with anhydrous magnesium sulfate, then filter under vacuum. Remove the solvent by rotary evaporation of the filtrate to obtain the hindered amine chlorinated compound. Step S5: Add 10 mmol of bisphenol AF and 20 mL of N,N-dimethylformamide to a three-necked flask equipped with a stirrer and thermometer. Stir the mixture at 20 °C and 200 r / min for 20 min. Then add 25 mmol of anhydrous potassium carbonate and 10 mL of toluene and continue stirring for 20 min. Then add 20 mmol of hindered amine chlorine compound and heat to 100 °C and continue stirring for 3 h. After the reaction is complete, filter the reaction product while it is hot. Pour the filtrate into distilled water and centrifuge. Recrystallize the precipitate with a mixed solvent B composed of N,N-dimethylformamide and ethanol in a volume ratio of 3:1 to obtain the fluorinated hindered amine compound. Step S6: Weigh out 90 parts by weight of polypropylene resin, 1 part of alkenyl grafted titanium dioxide, 0.3 parts of fluorine-containing hindered amine compound, 0.8 parts of bis-tert-butylperoxyisopropylbenzene, 0.2 parts of calcium stearate, and 0.1 parts of erucamide, and set aside; the polypropylene resin is PP L5E89. Step S7: Polypropylene resin, alkenyl grafted titanium dioxide, fluorinated hindered amine compound, bis-tert-butylperoxyisopropylbenzene, calcium stearate and erucamide are added to a twin-screw extruder and melt-extruded at a temperature of 180℃ and a screw speed of 80r / min. After casting, a high weather-resistant composite geomembrane with a thickness of 1.0mm is obtained.
[0020] Example 2: This example describes a method for preparing a high weather-resistant composite geomembrane, comprising the following steps: Step S1: Add 1.1g of polyvinylpyrrolidone (PVP K30) and 100mL of cerium nitrate solution with a molar concentration of 0.06mol / L to a three-necked flask equipped with a stirrer, thermometer, and constant pressure dropping funnel. Stir the reaction at 22℃ and a stirring rate of 250r / min for 25min. Then, while stirring, add 3mL of ammonia solution with a molar concentration of 2.2mol / L dropwise, controlling the dropping rate to 2 drops / s. After the addition is complete, continue stirring the reaction for 1.5h to obtain cerium oxide sol. Step S2: Add 5g of nano-titanium dioxide with an average particle size of 100nm and 65mL of cerium oxide sol to a three-necked flask equipped with a stirrer and thermometer. Stir the reaction at 22℃ and 250r / min for 25min. Then adjust the pH to 9 with 22% sodium hydroxide solution. Continue stirring at 65℃ for 2h. After the reaction is complete, cool the reaction product to room temperature, centrifuge, and place the precipitate in a vacuum drying oven to dry at 82℃ for 2.5h to obtain coated titanium dioxide. Step S3: Add 80 mL of anhydrous ethanol and 12 mL of deionized water to a three-necked flask equipped with a stirrer and thermometer. Stir the mixture at 22 °C and 250 r / min for 4 min. Then adjust the pH to 5.5 with glacial acetic acid. Add 5 g of coated titanium dioxide and 3 g of silane coupling agent KH-570 and continue stirring for 25 min. Then raise the temperature to 82 °C and continue stirring for 7 h. After the reaction is complete, cool the reaction product to room temperature, centrifuge, and place the precipitate in a vacuum drying oven. Dry it at 82 °C for 2.5 h to obtain alkenyl grafted coated titanium dioxide. Step S4: Add 10 mmol of cyanuric chloride and 25 mL of toluene to a three-necked flask equipped with a stirrer, thermometer, gas delivery tube, and constant pressure dropping funnel. Purge with nitrogen and stir for 25 min at 3 °C and 250 r / min. Then add 20 mmol of N-butyl-2,2,6,6-tetramethyl-4-piperidinamine and continue stirring for 2.5 h. Then add 3 mL of 35% sodium hydroxide solution dropwise while stirring, controlling the dropping rate to 2 drops / s. After the addition is complete, raise the temperature to 72 °C and continue stirring for 12 h. After the reaction is complete, cool the reaction product to room temperature and add it to a mixed solvent A composed of deionized water and ethyl acetate in a volume ratio of 2:1. After standing and separating the layers, dry the organic phase with anhydrous magnesium sulfate, then filter under vacuum. Remove the solvent by rotary evaporation of the filtrate to obtain the hindered amine chlorinated compound. Step S5: Add 10 mmol of bisphenol AF and 25 mL of N,N-dimethylformamide to a three-necked flask equipped with a stirrer and thermometer. Stir the mixture at 22 °C and 250 r / min for 25 min. Then add 28 mmol of anhydrous potassium carbonate and 11 mL of toluene and continue stirring for 25 min. Then add 20 mmol of hindered amine chlorine compound and heat to 105 °C and continue stirring for 4 h. After the reaction is complete, filter the reaction product while it is hot. Pour the filtrate into distilled water and centrifuge. Recrystallize the precipitate with a mixed solvent B composed of N,N-dimethylformamide and ethanol in a volume ratio of 3:1 to obtain the fluorinated hindered amine compound. Step S6: Weigh out 92 parts by weight of polypropylene resin, 4 parts by weight of alkenyl grafted titanium dioxide, 0.9 parts by weight of fluorinated hindered amine compound, 1 part by weight of bis-tert-butylperoxyisopropylbenzene, 0.3 parts by weight of calcium stearate and 0.2 parts by weight of erucamide, and set aside; the polypropylene resin is PP L5E89. Step S7: Polypropylene resin, alkenyl grafted titanium dioxide, fluorinated hindered amine compound, bis-tert-butylperoxyisopropylbenzene, calcium stearate and erucamide are added to a twin-screw extruder and melt-extruded at a temperature of 190℃ and a screw speed of 90r / min. After casting, a high weather-resistant composite geomembrane with a thickness of 1.0mm is obtained.
[0021] Example 3: This example describes a method for preparing a high weather-resistant composite geomembrane, comprising the following steps: Step S1: Add 1.2g of polyvinylpyrrolidone (PVP K30) and 100mL of cerium nitrate solution with a molar concentration of 0.07mol / L to a three-necked flask equipped with a stirrer, thermometer, and constant pressure dropping funnel. Stir the reaction at 25℃ and a stirring rate of 300r / min for 30min. Then, while stirring, add 4mL of ammonia solution with a molar concentration of 2.5mol / L dropwise, controlling the dropping rate to 3 drops / s. After the addition is complete, continue stirring the reaction for 2h to obtain cerium oxide sol. Step S2: Add 5g of nano-titanium dioxide with an average particle size of 100nm and 70mL of cerium oxide sol to a three-necked flask equipped with a stirrer and thermometer. Stir the reaction at 25℃ and 300r / min for 30min. Then adjust the pH to 9.5 with 25% sodium hydroxide solution. Continue stirring the reaction at 70℃ for 3h. After the reaction is completed, cool the reaction product to room temperature, centrifuge it, and place the precipitate in a vacuum drying oven to dry at 85℃ for 3h to obtain coated titanium dioxide. Step S3: Add 85 mL of anhydrous ethanol and 15 mL of deionized water to a three-necked flask equipped with a stirrer and thermometer. Stir the reaction at 25 °C and 300 r / min for 5 min. Then adjust the pH to 6 with glacial acetic acid. Add 5 g of coated titanium dioxide and 5 g of silane coupling agent KH-570 and continue stirring for 30 min. Then raise the temperature to 85 °C and continue stirring for 8 h. After the reaction is complete, cool the reaction product to room temperature, centrifuge, and place the precipitate in a vacuum drying oven. Dry it at 85 °C for 3 h to obtain alkenyl grafted coated titanium dioxide. Step S4: Add 10 mmol of cyanuric chloride and 30 mL of toluene to a three-necked flask equipped with a stirrer, thermometer, gas delivery tube, and constant pressure dropping funnel. Purge with nitrogen and stir for 30 min at 5 °C and 300 r / min. Then add 20 mmol of N-butyl-2,2,6,6-tetramethyl-4-piperidinamine and continue stirring for 3 h. Then add 4 mL of 40% sodium hydroxide solution dropwise while stirring, controlling the dropping rate to 3 drops / s. After the addition is complete, raise the temperature to 75 °C and continue stirring for 15 h. After the reaction is complete, cool the reaction product to room temperature and add it to a mixed solvent A of deionized water and ethyl acetate in a volume ratio of 2:1. After standing and separating the layers, dry the organic phase with anhydrous magnesium sulfate, then filter under vacuum. Remove the solvent by rotary evaporation of the filtrate to obtain the hindered amine chlorinated compound. Step S5: Add 10 mmol of bisphenol AF and 30 mL of N,N-dimethylformamide to a three-necked flask equipped with a stirrer and thermometer. Stir the mixture at 25 °C and 300 r / min for 30 min. Then add 30 mmol of anhydrous potassium carbonate and 12 mL of toluene and continue stirring for 30 min. Then add 20 mmol of hindered amine chlorine compound and heat to 110 °C and continue stirring for 5 h. After the reaction is complete, filter the reaction product while it is hot. Pour the filtrate into distilled water and centrifuge. Recrystallize the precipitate with a mixed solvent B composed of N,N-dimethylformamide and ethanol in a volume ratio of 3:1 to obtain the fluorinated hindered amine compound. Step S6: Weigh out 95 parts by weight of polypropylene resin, 7 parts by weight of alkenyl grafted titanium dioxide, 1.5 parts by weight of fluorinated hindered amine compound, 1.2 parts by weight of bis-tert-butylperoxyisopropylbenzene, 0.4 parts by weight of calcium stearate and 0.3 parts by weight of erucamide, and set aside; the polypropylene resin is PP L5E89. Step S7: Polypropylene resin, alkenyl grafted titanium dioxide, fluorinated hindered amine compound, bis-tert-butylperoxyisopropylbenzene, calcium stearate and erucamide are added to a twin-screw extruder and melt-extruded at a temperature of 200℃ and a screw speed of 100r / min. After casting, a high weather-resistant composite geomembrane with a thickness of 1.0mm is obtained.
[0022] Comparative Example 1: This comparative example illustrates a method for preparing a high weather-resistant composite geomembrane, comprising the following steps: Step S1: Weigh out 95 parts by weight of polypropylene resin, 1.2 parts by weight of bis-tert-butylperoxyisopropylbenzene, 0.4 parts by weight of calcium stearate and 0.3 parts by weight of erucamide, and set aside; the polypropylene resin is PP L5E89; Step S2: Polypropylene resin, bis-tert-butylperoxyisopropylbenzene, calcium stearate and erucamide are added to a twin-screw extruder and melt-extruded at a temperature of 200℃ and a screw speed of 100r / min. After casting, a high weather-resistant composite geomembrane with a thickness of 1.0mm is obtained.
[0023] Comparative Example 2: This comparative example illustrates a method for preparing a high weather-resistant composite geomembrane, comprising the following steps: Step S1: Add 1.2g of polyvinylpyrrolidone (PVP K30) and 100mL of cerium nitrate solution with a molar concentration of 0.07mol / L to a three-necked flask equipped with a stirrer, thermometer, and constant pressure dropping funnel. Stir the reaction at 25℃ and a stirring rate of 300r / min for 30min. Then, while stirring, add 4mL of ammonia solution with a molar concentration of 2.5mol / L dropwise, controlling the dropping rate to 3 drops / s. After the addition is complete, continue stirring the reaction for 2h to obtain cerium oxide sol. Step S2: Add 5g of nano-titanium dioxide with an average particle size of 100nm and 70mL of cerium oxide sol to a three-necked flask equipped with a stirrer and thermometer. Stir the reaction at 25℃ and 300r / min for 30min. Then adjust the pH to 9.5 with 25% sodium hydroxide solution. Continue stirring the reaction at 70℃ for 3h. After the reaction is completed, cool the reaction product to room temperature, centrifuge it, and place the precipitate in a vacuum drying oven to dry at 85℃ for 3h to obtain coated titanium dioxide. Step S3: Add 85 mL of anhydrous ethanol and 15 mL of deionized water to a three-necked flask equipped with a stirrer and thermometer. Stir the reaction at 25 °C and 300 r / min for 5 min. Then adjust the pH to 6 with glacial acetic acid. Add 5 g of coated titanium dioxide and 5 g of silane coupling agent KH-570 and continue stirring for 30 min. Then raise the temperature to 85 °C and continue stirring for 8 h. After the reaction is complete, cool the reaction product to room temperature, centrifuge, and place the precipitate in a vacuum drying oven. Dry it at 85 °C for 3 h to obtain alkenyl grafted coated titanium dioxide. Step S4: Weigh out 95 parts by weight of polypropylene resin, 7 parts by weight of alkenyl grafted titanium dioxide, 1.2 parts by weight of bis-tert-butylperoxyisopropylbenzene, 0.4 parts by weight of calcium stearate and 0.3 parts by weight of erucamide, and set aside; the polypropylene resin is PPL5E89. Step S5: Polypropylene resin, alkenyl grafted titanium dioxide, bis-tert-butylperoxyisopropylbenzene, calcium stearate and erucamide are added to a twin-screw extruder and melt-extruded at a temperature of 200℃ and a screw speed of 100r / min. After casting, a high weather-resistant composite geomembrane with a thickness of 1.0mm is obtained.
[0024] Comparative Example 3: This comparative example illustrates a method for preparing a high weather-resistant composite geomembrane, comprising the following steps: Step S1: 10 mmol of cyanuric chloride and 30 mL of toluene were added to a three-necked flask equipped with a stirrer, thermometer, gas delivery tube and constant pressure dropping funnel. Nitrogen gas was introduced for protection, and the mixture was stirred for 30 min at 5 °C and a stirring rate of 300 r / min. Then, 20 mmol of N-butyl-2,2,6,6-tetramethyl-4-piperidinamine was added and the mixture was stirred for 3 h. Then, 4 mL of 40% sodium hydroxide solution was added dropwise while stirring, with the dropping rate controlled at 3 drops / s. After the addition was completed, the temperature was raised to 75 °C and the mixture was stirred for 15 h. After the reaction was completed, the reaction product was cooled to room temperature and then added to a mixed solvent A composed of deionized water and ethyl acetate in a volume ratio of 2:1. The mixture was then allowed to stand and separate into layers. The organic phase was dried with anhydrous magnesium sulfate and then filtered under vacuum. The solvent was removed by rotary evaporation of the filtrate to obtain the hindered amine chlorinated compound. Step S2: Add 10 mmol of bisphenol AF and 30 mL of N,N-dimethylformamide to a three-necked flask equipped with a stirrer and thermometer. Stir the mixture at 25 °C and 300 r / min for 30 min. Then add 30 mmol of anhydrous potassium carbonate and 12 mL of toluene and continue stirring for another 30 min. Next, add 20 mmol of hindered amine chlorine compound and heat to 110 °C and continue stirring for 5 h. After the reaction is complete, filter the reaction product while it is hot. Pour the filtrate into distilled water and centrifuge. Recrystallize the precipitate with a mixed solvent B consisting of N,N-dimethylformamide and ethanol in a volume ratio of 3:1 to obtain a fluorinated hindered amine compound. Step S3: Weigh out 95 parts by weight of polypropylene resin, 1.5 parts by weight of fluorinated hindered amine compound, 1.2 parts by weight of bis-tert-butylperoxyisopropylbenzene, 0.4 parts by weight of calcium stearate and 0.3 parts by weight of erucamide, and set aside; the polypropylene resin is PP L5E89. Step S4: Polypropylene resin, fluorinated hindered amine compound, bis-tert-butylperoxyisopropylbenzene, calcium stearate and erucamide are added to a twin-screw extruder and melt-extruded at a temperature of 200℃ and a screw speed of 100r / min. After casting, a high weather-resistant composite geomembrane with a thickness of 1.0mm is obtained.
[0025] Comparative Example 4: This comparative example illustrates a method for preparing a high weather-resistant composite geomembrane, comprising the following steps: Step S1: Weigh out 95 parts by weight of polypropylene resin, 7 parts by weight of nano-titanium dioxide with an average particle size of 100 nm, 1.5 parts by weight of N-butyl-2,2,6,6-tetramethyl-4-piperidinamine, 1.2 parts by weight of bis-tert-butylperoxyisopropylbenzene, 0.4 parts by weight of calcium stearate, and 0.3 parts by weight of erucamide, and set aside; the polypropylene resin is PP L5E89; Step S2: Polypropylene resin, nano-titanium dioxide with an average particle size of 100nm, N-butyl-2,2,6,6-tetramethyl-4-piperidinamine, bis-tert-butylperoxyisopropylbenzene, calcium stearate and erucamide are added to a twin-screw extruder and melt-extruded at a temperature of 200℃ and a screw speed of 100r / min. After casting, a high weather-resistant composite geomembrane with a thickness of 1.0mm is obtained.
[0026] The high weather-resistant composite geomembranes of Examples 1-3 and Comparative Examples 1-4 were subjected to ultraviolet aging tests according to GB / T 16422.3, and then tensile strength tests were conducted according to GB / T 1040.3-2006. The test results are shown in the table below:
[0027] Referring to the data in the table above, and based on the comparison between Examples 1-3 and Comparative Examples 1-4, it can be seen that the high weather-resistant composite geomembrane of this application has good mechanical properties and mechanical property retention performance, indicating that the high weather-resistant composite geomembrane has excellent weather resistance.
[0028] In the description of this specification, references to terms such as "an embodiment," "example," "specific example," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the invention. In this specification, illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.
[0029] The above description is merely an example and illustration of the present invention. Those skilled in the art can make various modifications or additions to the specific embodiments described or use similar methods to replace them, as long as they do not deviate from the invention or exceed the scope defined in this application, they should all fall within the protection scope of the present invention.
Claims
1. A high weather-resistant composite geomembrane, characterized in that, Includes the following components by weight: The composition includes 90-95 parts of polypropylene resin, 1-7 parts of alkenyl grafted titanium dioxide, 0.3-1.5 parts of fluorine-containing hindered amine compound, 0.8-1.2 parts of bis-tert-butylperoxyisopropylbenzene, 0.2-0.4 parts of calcium stearate, and 0.1-0.3 parts of erucamide. The alkenyl-grafted coated titanium dioxide is prepared by the following steps: Step a1: Polyvinylpyrrolidone and cerium nitrate solution are stirred and reacted, then ammonia water is added dropwise. After the addition is complete, the reaction is stirred and reacted to obtain cerium oxide sol. Step a2: The nano-titanium dioxide and cerium oxide sol were stirred and reacted. Then the pH was adjusted with sodium hydroxide solution, and the reaction was continued by stirring. After the reaction was completed, the reaction product was cooled, centrifuged, and the precipitate was dried to obtain coated titanium dioxide. Step a3: Anhydrous ethanol and deionized water were stirred and reacted. Then, the pH was adjusted with glacial acetic acid. Then, coated titanium dioxide and silane coupling agent KH-570 were added and the reaction was continued with stirring. After the reaction was completed, the reaction product was cooled, centrifuged, and the precipitate was dried to obtain alkenyl grafted coated titanium dioxide.
2. The high weather-resistant composite geomembrane according to claim 1, characterized in that, In step a1, the ratio of polyvinylpyrrolidone, cerium nitrate solution, and ammonia is 1-1.2g:100mL:2-4mL; the polyvinylpyrrolidone is PVP K30; the molar concentration of the cerium nitrate solution is 0.05-0.07mol / L; and the molar concentration of the ammonia is 2-2.5mol / L.
3. The high weather-resistant composite geomembrane according to claim 1, characterized in that, In step a2, the ratio of nano-titanium dioxide to cerium oxide sol is 5g:60-70mL; the average particle size of the nano-titanium dioxide is 100nm; and the mass fraction of the sodium hydroxide solution is 20-25%.
4. The high weather-resistant composite geomembrane according to claim 1, characterized in that, The ratio of anhydrous ethanol, deionized water, coated titanium dioxide, and silane coupling agent KH-570 in step a3 is 75-85 mL: 10-15 mL: 5 g: 1-5 g.
5. The high weather-resistant composite geomembrane according to claim 1, characterized in that, The fluorine-containing hindered amine compound was prepared by the following steps: Step b1: Cyanurium chloride and toluene were stirred and reacted. Then N-butyl-2,2,6,6-tetramethyl-4-piperidinamine was added and the reaction was stirred. Then sodium hydroxide solution was added dropwise. After the addition was completed, the reaction was stirred and reacted. After the reaction was completed, the reaction product was cooled and then added to mixed solvent A. After standing and separating the layers, the organic phase was dried and then vacuum filtered. The filtrate was evaporated by rotary evaporation to obtain the hindered amine chlorine compound. Step b2: Bisphenol AF and N,N-dimethylformamide were stirred and reacted. Then anhydrous potassium carbonate, toluene and hindered amine chlorine compound were added and the reaction was continued with stirring. After the reaction was completed, the reaction product was filtered while hot. The filtrate was poured into distilled water and then centrifuged. The precipitate was recrystallized with mixed solvent B to obtain fluorine-containing hindered amine compound.
6. The high weather-resistant composite geomembrane according to claim 5, characterized in that, In step b1, the ratio of cyanuric chloride, toluene, N-butyl-2,2,6,6-tetramethyl-4-piperidinamine, and sodium hydroxide solution is 10 mmol: 20-30 mL: 20 mmol: 2-4 mL; the mass fraction of the sodium hydroxide solution is 30-40%; and the mixed solvent A is a mixture of deionized water and ethyl acetate in a volume ratio of 2:
1.
7. The high weather-resistant composite geomembrane according to claim 5, characterized in that, In step b2, the ratio of bisphenol AF, N,N-dimethylformamide, anhydrous potassium carbonate, toluene, and hindered amine chlorine compound is 10 mmol: 20-30 mL: 25-30 mmol: 10-12 mL: 20 mmol; the mixed solvent B is a mixture of N,N-dimethylformamide and ethanol in a volume ratio of 3:
1.
8. A method for preparing a high weather-resistant composite geomembrane, characterized in that, The preparation of the high weather-resistant composite geomembrane as described in any one of claims 1-7 includes the following steps: Step 1: Weigh out 90-95 parts by weight of polypropylene resin, 1-7 parts by weight of alkenyl grafted titanium dioxide, 0.3-1.5 parts by weight of fluorine-containing hindered amine compound, 0.8-1.2 parts by weight of bis-tert-butylperoxyisopropylbenzene, 0.2-0.4 parts by weight of calcium stearate and 0.1-0.3 parts by weight of erucamide, and set aside; the polypropylene resin is PP L5E89; Step 2: Polypropylene resin, alkenyl grafted titanium dioxide, fluorinated hindered amine compound, bis-tert-butylperoxyisopropylbenzene, calcium stearate and erucamide are added to a twin-screw extruder and melt-extruded at a temperature of 180-200℃ and a screw speed of 80-100 r / min. After casting, a high weather-resistant composite geomembrane is obtained.