High-tensile anti-cracking geomembrane and preparation method thereof

Abstract

The invention relates to the field of geomembranes, in particular to a high-tensile anti-cracking geomembrane and a preparation method thereof, and aims to solve the problems that an existing geomembrane is poor in tensile anti-cracking performance and ultraviolet aging resistance, and wide application of the geomembrane in a severe environment is limited. According to the high-tensile anti-cracking geomembrane, the titanium dioxide loaded whiskers coated with the polydopamine are used as a reinforcing material, the tensile strength of the geomembrane is effectively improved through the ultrahigh mechanical property of the titanium dioxide loaded whiskers, the mechanical property of the geomembrane is remarkably enhanced, and cracks are effectively inhibited; by adding hindered amine thienyl metal porphyrin, light energy can be effectively absorbed and dispersed, free radicals generated in the aging process are passivated, aging continuation is inhibited, and degradation caused by aging is avoided, so that long-term stability and high performance of the geomembrane under severe environment conditions are maintained, and the service life of the geomembrane is prolonged.

Description

TECHNICAL FIELD

[0001] The application relates to the field of geomembranes, in particular to a high-tensile anti-cracking geomembrane and a preparation method thereof. BACKGROUND

[0002] In the field of geotechnical engineering, geomembranes are widely used in water conservancy projects, environmental governance, mining engineering and other fields as excellent materials for seepage prevention, isolation, filtration and drainage. However, the traditional geomembranes have poor tensile anti-cracking performance, are prone to cracking and breaking during use, and have poor ultraviolet aging resistance, so that the performance of the geomembranes is quickly degraded after long-term light aging, resulting in a decrease or even failure of the performance of the geomembranes, and limiting the wide application of the geomembranes in harsh environments. Therefore, it is of great practical significance to develop a high-tensile anti-cracking geomembrane and a preparation method thereof.

[0003] In view of the above technical defects, a solution is provided. SUMMARY

[0004] In order to overcome the above technical problems, the purpose of the present application is to provide a high-tensile anti-cracking geomembrane and a preparation method thereof, which solves the problem that the existing geomembranes have poor tensile anti-cracking performance and poor ultraviolet aging resistance, and limits the wide application of the geomembranes in harsh environments.

[0005] The purpose of the present application can be achieved by the following technical solutions. In a first aspect, the present application provides a high-tensile anti-cracking geomembrane, comprising the following components by weight: low-density polyethylene 70-75 parts, high-density polyethylene 20-22 parts, ethylene-vinyl acetate copolymer 9-15 parts, polydopamine-coated titanium dioxide loaded whisker 3-11 parts, hindered amine thiophene metal porphyrin 1.5-6.5 parts, calcium stearate 0.5-1.5 parts, vinyl bis-stearamide 0.3-0.9 parts, and antioxidant 0.2-0.4 parts; The polydopamine-coated titanium dioxide loaded whisker is prepared by the following steps: Step a1: silicon carbide whiskers and nitric acid solution are added to a three-necked flask equipped with a stirrer and a thermometer, and stirred at a temperature of 20-25 DEG C and a stirring rate of 200-300 r / min for 20-30 min, then heated to 60-65 DEG C and stirred for 3-5 h, and then cooled to room temperature, centrifuged, and the precipitate was washed with anhydrous ethanol and distilled water for 3-5 times, and then placed in a vacuum drying oven and dried at a temperature of 60-70 DEG C for 2-3 h to obtain etched whiskers; Step a2: tetra-n-butyl titanate, hydrochloric acid solution and ethanol solution are added into a reaction kettle, stirring is carried out at a temperature of 40-45℃ and a stirring speed of 200-300r / min for 60-90min, then etching whiskers are added and the reaction is continued at a temperature of 150-160℃ for 1-3h, after the reaction is completed, the reaction product is cooled to room temperature, then centrifugation is carried out, the precipitate is washed with anhydrous ethanol and distilled water for 3-5 times, then it is placed in a vacuum drying box and dried at a temperature of 60-70℃ for 4-6h, thereby obtaining titanium dioxide loaded whiskers; Step a3: titanium dioxide loaded whiskers, ammonia water, dopamine hydrochloride and deionized water are added into a three-necked flask equipped with a stirrer and a thermometer, stirring is carried out at a temperature of 20-25℃ and a stirring speed of 200-300r / min for 3-6h, after the reaction is completed, the reaction product is centrifuged, the precipitate is washed with distilled water for 3-5 times, then it is placed in a vacuum drying box and dried at a temperature of 60-70℃ for 2-3h, thereby obtaining polydopamine coated titanium dioxide loaded whiskers.

[0006] As a preferred embodiment of the present application, the use amount ratio of the silicon carbide whiskers and the nitric acid solution in step a1 is 3g:30-40mL.

[0007] As a preferred embodiment of the present application, the average diameter of the silicon carbide whiskers in step a1 is 2μm and the average length is 45μm; the mass fraction of the nitric acid solution is 30-40%.

[0008] As a preferred embodiment of the present application, the use amount ratio of the tetra-n-butyl titanate, the hydrochloric acid solution, the ethanol solution and the etching whiskers in step a2 is 2-5mL:2-2.5mL:50-55mL:5g.

[0009] As a preferred embodiment of the present application, the mass fraction of the hydrochloric acid solution in step a2 is 36-38% and the volume fraction of the ethanol solution is 80-90%.

[0010] As a preferred embodiment of the present application, the use amount ratio of the titanium dioxide loaded whiskers, the ammonia water, the dopamine hydrochloride and the deionized water in step a3 is 2g:10-15mL:0.5-1.3g:40-45mL.

[0011] As a preferred embodiment of the present application, the mass fraction of the ammonia water in step a3 is 25-27%.

[0012] As a preferred embodiment of the present application, the hindered amine thienyl metalloporphyrin is prepared by the following steps: Step b1: 5-chlorothiophene-2-carboxaldehyde, glacial acetic acid were added into a three-necked flask equipped with a stirrer, a thermometer, a gas inlet tube and a constant pressure dropping funnel, and then nitrogen was bubbled in, and the mixture was stirred at a temperature of 20-25 DEG C and a stirring speed of 200-300 r / min for 10-20 min, and then the temperature was raised to 120-130 DEG C, and the stirring was continued for 10-20 min, and then pyrrole was added drop by drop while stirring, and the dropping speed was controlled at 1-2 drops / s, and after the addition was completed, the stirring was continued for 1-3 h, and then the reaction product was cooled to room temperature, and then poured into anhydrous methanol, and then it was left to stand for 10-12 h, and then vacuum filtration was carried out, and the filter cake was purified by silica gel column chromatography using mixed solvent a, and then a chlorothienyl porphyrin was obtained. Step b2: chlorothienyl porphyrin, 2,2,6,6-tetramethylpiperidinamine, anhydrous potassium carbonate, toluene and N,N-dimethylformamide were added into a three-necked flask equipped with a stirrer, a thermometer and a gas inlet tube, and then nitrogen was bubbled in, and the mixture was stirred at a temperature of 20-25 DEG C and a stirring speed of 200-300 r / min for 20-30 min, and then the temperature was raised to 60-70 DEG C, and the stirring was continued for 1-2 h, and then the temperature was raised to 120-130 DEG C, and the stirring was continued for 3-5 h, and then the reaction product was cooled to room temperature, and then poured into ice water, and then vacuum filtration was carried out, and the filter cake was washed with anhydrous methanol for 3-5 times, and then it was left to stand in a vacuum drying oven at a temperature of 50-60 DEG C for 2-4 h, and then a hindered amine thienyl porphyrin was obtained. Step b3: hindered amine thienyl porphyrin, nickel acetate tetrahydrate, acetic acid and chloroform were added into a three-necked flask equipped with a stirrer, a thermometer and a gas inlet tube, and then nitrogen was bubbled in, and the mixture was stirred at a temperature of 20-25 DEG C and a stirring speed of 200-300 r / min for 20-30 min, and then the temperature was raised to 110-120 DEG C, and the stirring was continued for 3-5 h, and then the reaction product was cooled to room temperature, and then the solvent was removed by rotary evaporation, and then it was poured into distilled water, and then vacuum filtration was carried out, and the filter cake was purified by silica gel column chromatography using mixed solvent b, and then a hindered amine thienyl metalloporphyrin was obtained.

[0013] As a preferred embodiment of the present application, the amount ratio of 5-chlorothiophene-2-carboxaldehyde, glacial acetic acid and pyrrole in step b1 is 40 mmol:100-120 mL:40 mmol.

[0014] As a preferred embodiment of the present application, the mixed solvent a in step b1 is a mixture of dichloromethane and n-hexane in a volume ratio of 3-5:1.

[0015] As a preferred embodiment of the present application, the amount ratio of the chlorothienyl porphyrin, 2,2,6,6-tetramethylpiperidine amine, anhydrous potassium carbonate, toluene and N,N-dimethylformamide in step b2 is 10 mmol: 44-48 mmol: 60-70 mmol: 50-60 mL: 90-100 mL.

[0016] As a preferred embodiment of the present application, the amount ratio of the hindered amine thienyl porphyrin, nickel acetate tetrahydrate, acetic acid and chloroform in step b3 is 1 g: 3-3.5 g: 30-35 mL: 30-35 mL.

[0017] As a preferred embodiment of the present application, the mixed solvent b in step b3 is a mixture of dichloromethane and petroleum ether in a volume ratio of 7-8:1.

[0018] In a second aspect, the present application provides a preparation method of high-tensile anti-cracking geomembrane, comprising the following steps: Step one: low density polyethylene 70-75 parts, high density polyethylene 20-22 parts, ethylene-vinyl acetate copolymer 9-15 parts, polydopamine-coated titanium dioxide loaded whisker 3-11 parts, hindered amine thienyl metalloporphyrin 1.5-6.5 parts, calcium stearate 0.5-1.5 parts, vinyl bis-stearamide 0.3-0.9 parts and antioxidant 0.2-0.4 parts are weighed according to weight parts, ready for use; Step two: low density polyethylene, high density polyethylene, ethylene-vinyl acetate copolymer, polydopamine-coated titanium dioxide loaded whisker, hindered amine thienyl metalloporphyrin, calcium stearate, vinyl bis-stearamide and antioxidant are added into a twin-screw extruder, and are melt extruded under the conditions that the screw rotation speed is 30-60 r / min and the five temperature zones are 160-170℃, 170-180℃, 180-190℃, 190-200℃ and 185-195℃ in sequence, and then are water-cooled and granulated to obtain geomembrane granules; Step three: the geomembrane granules are cast into a film by a casting machine to obtain high-tensile anti-cracking geomembrane.

[0019] As a preferred embodiment of the present application, the low density polyethylene is LDPE Q281.

[0020] As a preferred embodiment of the present application, the high density polyethylene is HDPE DMDA-8920.

[0021] As a preferred embodiment of the present application, the ethylene-vinyl acetate copolymer is ELVAX 450.

[0022] As a preferred embodiment of the present application, the antioxidant is antioxidant 1010.

[0023] Compared with the prior art, the application has the following beneficial effects: The application obtains the geomembrane granules by melt extrusion, water cooling and granulation of the low-density polyethylene, high-density polyethylene, ethylene-vinyl acetate copolymer, polydopamine-coated titanium dioxide loaded whisker, hindered amine thienyl metal porphyrin, calcium stearate, vinyl bis-stearamide and antioxidant; the geomembrane granules are drawn into a film by a casting machine to obtain the high-tensile and anti-cracking geomembrane; in the high-tensile and anti-cracking geomembrane, the polydopamine-coated titanium dioxide loaded whisker is used as a reinforcing material, the tensile strength of the geomembrane is effectively improved by the super-high mechanical property of the polydopamine-coated titanium dioxide loaded whisker, the mechanical property of the geomembrane is significantly enhanced, and the generation of cracks is effectively inhibited; the addition of the hindered amine thienyl metal porphyrin can effectively absorb and disperse light energy, passivate free radicals generated in the aging process, inhibit the aging extension, avoid degradation caused by aging, thereby maintaining the long-term stability and high performance of the geomembrane under harsh environmental conditions, and prolonging the service life of the geomembrane; In the process of preparing the geomembrane, a polydopamine-coated titanium dioxide loaded whisker is first prepared; the silicon carbide whisker is etched by a nitric acid solution to increase the roughness of the surface of the whisker, which is beneficial to the loading of titanium dioxide, to obtain etched whisker; then the titanium dioxide loaded whisker is obtained by loading titanium dioxide; and the polydopamine-coated titanium dioxide loaded whisker is obtained by coating polydopamine on the titanium dioxide loaded whisker; the silicon carbide whisker has excellent mechanical properties, and can form a three-dimensional network support structure in the geomembrane to significantly improve the tensile and anti-cracking properties of the geomembrane; the loading of titanium dioxide on the surface of the silicon carbide whisker can further improve the mechanical properties of the geomembrane, and also can reflect and absorb ultraviolet light to reduce the damage of ultraviolet radiation to the geomembrane; the coating of polydopamine on the titanium dioxide loaded whisker can increase the dispersibility of the titanium dioxide loaded whisker to avoid agglomeration, and can also significantly improve the bonding force between the titanium dioxide loaded whisker and the geomembrane by the adhesion of polydopamine; in addition, polydopamine itself has a broad spectrum of light absorption properties, which can further reduce the damage of ultraviolet radiation to the geomembrane, thereby endowing the geomembrane with excellent anti-ultraviolet aging properties and enabling the geomembrane to maintain high performance for a long time; A hindered amine thienyl metal porphyrin is also prepared in the process of preparing the geomembrane. 5-chlorothiophene-2-carboxaldehyde and pyrrole are used as raw materials to form a porphyrin ring, and the porphyrin ring contains a thienyl ring and a chlorine atom, to obtain a chlorothienyl porphyrin. The chlorine atom on the chlorothienyl porphyrin reacts with the amino group on the 2,2,6,6-tetramethylpiperidylamine to introduce a hindered amine structure, to obtain a hindered amine thienyl porphyrin. Then, the hindered amine thienyl porphyrin reacts with nickel acetate tetrahydrate, and the porphyrin ring on the hindered amine thienyl porphyrin is coordinated with nickel ions to form a metal porphyrin structure, to obtain a hindered amine thienyl metal porphyrin. The hindered amine thienyl metal porphyrin has multiple hindered amine groups in the molecular structure, which can effectively capture free radicals initiated by ultraviolet light. The thienyl ring and the metal porphyrin structure on the hindered amine thienyl metal porphyrin can both absorb ultraviolet light, and the two structures synergistically realize wide spectral response, giving the hindered amine thienyl metal porphyrin excellent ultraviolet absorption effect and converting it into heat energy. Therefore, under the synergistic action of the hindered amine group, the thienyl ring and the metal porphyrin structure, the hindered amine thienyl metal porphyrin has excellent anti-ultraviolet aging performance. When the hindered amine thienyl metal porphyrin is added to the geomembrane, it can effectively inhibit photooxidation, so that the geomembrane can maintain high performance for a long time. BRIEF DESCRIPTION OF DRAWINGS

[0024] In order to facilitate those skilled in the art to understand the present application, the technical solutions in the embodiments of the present application will be described below in conjunction with the drawings.

[0025] Figure 1 The tensile strength test results of the high-tensile anti-cracking geomembranes of Examples 1-3 and Comparative Examples 1-4 are shown in the following table. Figure 2 The tensile strength retention rate test results of the high-tensile anti-cracking geomembranes of Examples 1-3 and Comparative Examples 1-4 are shown in the following table. DETAILED DESCRIPTION

[0026] In order to make those skilled in the art better understand the present application, the technical solutions in the embodiments of the present application will be described below in conjunction with the drawings. Obviously, the described embodiments are only a part of the embodiments of the present application, not all. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor are within the scope of protection of the present application.

[0027] Example 1: This embodiment is a preparation method of a high-tensile anti-cracking geomembrane, comprising the following steps: Step S1: 3 g of silicon carbide whiskers with an average diameter of 2 μm and an average length of 45 μm, 30 mL of a 30% by mass nitric acid solution were added to a three-necked flask equipped with a stirrer and a thermometer, and stirred at a temperature of 20°C and a stirring rate of 200 r / min for 20 min, and then stirred at a temperature of 60°C for 3 h. After the reaction, the reaction product was cooled to room temperature, and then centrifuged. The precipitate was washed with anhydrous ethanol and distilled water three times in turn, and then placed in a vacuum drying oven and dried at a temperature of 60°C for 2 h to obtain etched whiskers; Step S2: 2 mL of tetrabutyl titanate, 2 mL of a 36% by mass hydrochloric acid solution, and 50 mL of an 80% by volume ethanol solution were added to a reaction kettle, and stirred at a temperature of 40°C and a stirring rate of 200 r / min for 60 min. Then, 5 g of the etched whiskers were added, and the temperature was raised to 150°C and the stirring was continued for 1 h. After the reaction, the reaction product was cooled to room temperature, and then centrifuged. The precipitate was washed with anhydrous ethanol and distilled water three times in turn, and then placed in a vacuum drying oven and dried at a temperature of 60°C for 4 h to obtain titanium dioxide loaded whiskers; Step S3: 2 g of the titanium dioxide loaded whiskers, 10 mL of a 25% by mass aqueous ammonia solution, 0.5 g of dopamine hydrochloride, and 40 mL of deionized water were added to a three-necked flask equipped with a stirrer and a thermometer, and stirred at a temperature of 20°C and a stirring rate of 200 r / min for 3 h. After the reaction, the reaction product was centrifuged, and the precipitate was washed with distilled water three times, and then placed in a vacuum drying oven and dried at a temperature of 60°C for 2 h to obtain polydopamine coated titanium dioxide loaded whiskers; Step S4: 40 mmol of 5-chlorothiophene-2-carboxaldehyde and 100 mL of glacial acetic acid were added to a three-necked flask equipped with a stirrer, a thermometer, a gas inlet tube, and a constant pressure dropping funnel, and protected by nitrogen. The mixture was stirred at a temperature of 20°C and a stirring rate of 200 r / min for 10 min, and then the temperature was raised to 120°C and the stirring was continued for 10 min. Then, 40 mmol of pyrrole was added dropwise while stirring, and the dropping rate was controlled at 1 drop / s. After the addition was completed, the stirring was continued for 1 h. After the reaction, the reaction product was cooled to room temperature, and then poured into anhydrous methanol. After standing for 10 h, the filter cake was purified by silica gel column chromatography using a mixed solvent a prepared by mixing dichloromethane and n-hexane at a volume ratio of 3:1 to obtain chlorothiophenyl porphyrin; Step S5: 10 mmol of chlorothiophene porphyrin, 44 mmol of 2,2,6,6-tetramethylpiperidinamine, 60 mmol of anhydrous potassium carbonate, 50 mL of toluene and 90 mL of N,N-dimethylformamide were added into a three-neck flask equipped with a stirrer, a thermometer and a gas inlet tube, protected by nitrogen, stirred at a temperature of 20℃ and a stirring rate of 200 r / min for 20 min, then stirred at a temperature of 60℃ for 1 h, and then stirred at a temperature of 120℃ for 3 h. After the reaction was completed, the reaction product was cooled to room temperature, then poured into ice water, vacuum filtered, the filter cake was washed with anhydrous methanol for 3 times, then placed in a vacuum drying oven, dried at a temperature of 50℃ for 2 h, and a hindered amine thiophene porphyrin was obtained; Step S6: 1 g of the hindered amine thiophene porphyrin, 3 g of nickel acetate tetrahydrate, 30 mL of acetic acid and 30 mL of chloroform were added into a three-neck flask equipped with a stirrer, a thermometer and a gas inlet tube, protected by nitrogen, stirred at a temperature of 20℃ and a stirring rate of 200 r / min for 20 min, then stirred at a temperature of 110℃ for 3 h. After the reaction was completed, the reaction product was cooled to room temperature, then rotary evaporated to remove the solvent, then poured into distilled water, vacuum filtered, and the filter cake was purified by silica gel column chromatography with a mixed solvent b of dichloromethane and petroleum ether in a volume ratio of 7:1, and a hindered amine thiophene metalloporphyrin was obtained; Step S7: low density polyethylene 70 parts, high density polyethylene 20 parts, ethylene-vinyl acetate copolymer 9 parts, polydopamine-coated titanium dioxide supported whisker 3 parts, hindered amine thiophene metalloporphyrin 1.5 parts, calcium stearate 0.5 parts, vinyl bis-stearamide 0.3 parts and antioxidant 0.2 parts were weighed according to weight parts, and prepared for use. The low density polyethylene was LDPE Q281; the high density polyethylene was HDPE DMDA-8920; the ethylene-vinyl acetate copolymer was ELVAX 450; and the antioxidant was antioxidant 1010; Step S8: The low density polyethylene, high density polyethylene, ethylene-vinyl acetate copolymer, polydopamine-coated titanium dioxide supported whisker, hindered amine thiophene metalloporphyrin, calcium stearate, vinyl bis-stearamide and antioxidant were added into a twin-screw extruder, melt extruded at a screw rotation speed of 30 r / min and five temperature zones of 160℃, 170℃, 180℃, 190℃ and 185℃ in sequence, water-cooled and granulated to obtain geotextile granules. Step S9: The geotextile granules were cast into a film by a casting machine to obtain a high-tensile anti-cracking geotextile film with a thickness of 1.5 mm.

[0028] Embodiment 2: A preparation method of a high-tensile anti-cracking geotextile film, comprising the following steps: Step S1: 3 g of silicon carbide whiskers with an average diameter of 2 μm and an average length of 45 μm, 35 mL of a 35% by mass nitric acid solution were added to a three-necked flask equipped with a stirrer and a thermometer, and stirred at a temperature of 22°C and a stirring rate of 250 r / min for 25 min, and then stirred at a temperature of 62°C for 4 h. After the reaction, the reaction product was cooled to room temperature, and then centrifuged. The precipitate was washed with anhydrous ethanol and distilled water four times in turn, and then placed in a vacuum drying oven and dried at a temperature of 65°C for 2.5 h to obtain etched whiskers; Step S2: 3.5 mL of tetrabutyl titanate, 2.2 mL of a 37% by mass hydrochloric acid solution, and 52 mL of an 85% by volume ethanol solution were added to a reaction kettle, and stirred at a temperature of 42°C and a stirring rate of 250 r / min for 75 min. Then, 5 g of etched whiskers were added, and the temperature was raised to 155°C and stirring was continued for 2 h. After the reaction, the reaction product was cooled to room temperature, and then centrifuged. The precipitate was washed with anhydrous ethanol and distilled water four times in turn, and then placed in a vacuum drying oven and dried at a temperature of 65°C for 5 h to obtain titanium dioxide loaded whiskers; Step S3: 2 g of titanium dioxide loaded whiskers, 12 mL of a 26% by mass aqueous ammonia solution, 0.9 g of dopamine hydrochloride, and 42 mL of deionized water were added to a three-necked flask equipped with a stirrer and a thermometer, and stirred at a temperature of 22°C and a stirring rate of 250 r / min for 4.5 h. After the reaction, the reaction product was centrifuged, and the precipitate was washed with distilled water four times. Then, the precipitate was placed in a vacuum drying oven and dried at a temperature of 65°C for 2.5 h to obtain polydopamine-coated titanium dioxide loaded whiskers; Step S4: 40 mmol of 5-chlorothiophene-2-carboxaldehyde and 110 mL of glacial acetic acid were added to a three-necked flask equipped with a stirrer, a thermometer, a gas inlet tube, and a constant-pressure dropping funnel, and protected by nitrogen. The mixture was stirred at a temperature of 22°C and a stirring rate of 250 r / min for 15 min, and then stirred at a temperature of 125°C for 15 min. Then, 40 mmol of pyrrole was added dropwise while stirring, and the dropping rate was controlled at 1 drop / s. After the addition was completed, the mixture was stirred for 2 h. After the reaction, the reaction product was cooled to room temperature, and then poured into anhydrous methanol. After standing for 11 h, the filter cake was purified by silica gel column chromatography using a mixed solvent a of dichloromethane and n-hexane (4:1 by volume) to obtain chlorothienyl porphyrin. Step S5: 10 mmol of chlorothiophene porphyrin, 46 mmol of 2,2,6,6-tetramethylpiperidinamine, 65 mmol of anhydrous potassium carbonate, 55 mL of toluene and 95 mL of N,N-dimethylformamide were added into a three-neck flask equipped with a stirrer, a thermometer and a gas inlet tube, protected by nitrogen, stirred at a temperature of 22℃ and a stirring rate of 250 r / min for 25 min, then stirred at a temperature of 65℃ for 1.5 h, and then stirred at a temperature of 125℃ for 4 h. After the reaction was completed, the reaction product was cooled to room temperature, then poured into ice water, vacuum filtered, and the filter cake was washed with anhydrous methanol for 4 times, then placed in a vacuum drying oven, dried at a temperature of 55℃ for 3 h, and hindered amine thiophene porphyrin was obtained; Step S6: 1 g of hindered amine thiophene porphyrin, 3.2 g of nickel acetate tetrahydrate, 32 mL of acetic acid and 32 mL of chloroform were added into a three-neck flask equipped with a stirrer, a thermometer and a gas inlet tube, protected by nitrogen, stirred at a temperature of 22℃ and a stirring rate of 250 r / min for 25 min, then stirred at a temperature of 115℃ for 4 h. After the reaction was completed, the reaction product was cooled to room temperature, then rotary evaporated to remove the solvent, then poured into distilled water, vacuum filtered, and the filter cake was purified by silica gel column chromatography with a mixed solvent b of dichloromethane and petroleum ether in a volume ratio of 7.5:1, and hindered amine thiophene metalloporphyrin was obtained; Step S7: low density polyethylene 72 parts, high density polyethylene 21 parts, ethylene-vinyl acetate copolymer 12 parts, polydopamine-coated titanium dioxide loaded whisker 7 parts, hindered amine thiophene metalloporphyrin 4 parts, calcium stearate 1 part, vinyl bis-stearamide 0.6 part and antioxidant 0.3 part were weighed according to weight parts, and prepared for use. The low density polyethylene was LDPE Q281; the high density polyethylene was HDPE DMDA-8920; the ethylene-vinyl acetate copolymer was ELVAX 450; and the antioxidant was antioxidant 1010; Step S8: The low density polyethylene, high density polyethylene, ethylene-vinyl acetate copolymer, polydopamine-coated titanium dioxide loaded whisker, hindered amine thiophene metalloporphyrin, calcium stearate, vinyl bis-stearamide and antioxidant were added into a twin-screw extruder, melt extruded at a screw rotation speed of 45 r / min and five temperature zones of 165℃, 175℃, 185℃, 195℃ and 190℃ in sequence, water-cooled and granulated to obtain geomembrane granules. Step S9: The geomembrane granules were cast into a film by a casting machine to obtain a high-tensile anti-cracking geomembrane with a thickness of 1.5 mm.

[0029] Embodiment 3: A preparation method of a high-tensile anti-cracking geomembrane, comprising the following steps: Step S1: 3 g of silicon carbide whiskers with an average diameter of 2 μm and an average length of 45 μm, 40 mL of a 40% by mass nitric acid solution were added to a three-necked flask equipped with a stirrer and a thermometer, and stirred at a temperature of 25°C and a stirring rate of 300 r / min for 30 min, and then stirred at a temperature of 65°C for 5 h. After the reaction, the reaction product was cooled to room temperature, and then centrifuged. The precipitate was washed with anhydrous ethanol and distilled water five times in turn, and then placed in a vacuum drying oven and dried at a temperature of 70°C for 3 h to obtain etched whiskers; Step S2: 5 mL of tetrabutyl titanate, 2.5 mL of a 38% by mass hydrochloric acid solution, and 55 mL of a 90% by volume ethanol solution were added to a reaction kettle, and stirred at a temperature of 45°C and a stirring rate of 300 r / min for 90 min. Then, 5 g of the etched whiskers were added, and the temperature was raised to 160°C to continue stirring for 3 h. After the reaction, the reaction product was cooled to room temperature, and then centrifuged. The precipitate was washed with anhydrous ethanol and distilled water five times in turn, and then placed in a vacuum drying oven and dried at a temperature of 70°C for 6 h to obtain titanium dioxide loaded whiskers; Step S3: 2 g of the titanium dioxide loaded whiskers, 15 mL of a 27% by mass aqueous ammonia solution, 1.3 g of dopamine hydrochloride, and 45 mL of deionized water were added to a three-necked flask equipped with a stirrer and a thermometer, and stirred at a temperature of 25°C and a stirring rate of 300 r / min for 6 h. After the reaction, the reaction product was centrifuged, and the precipitate was washed with distilled water five times, and then placed in a vacuum drying oven and dried at a temperature of 70°C for 3 h to obtain polydopamine coated titanium dioxide loaded whiskers; Step S4: 40 mmol of 5-chlorothiophene-2-carboxaldehyde and 120 mL of glacial acetic acid were added to a three-necked flask equipped with a stirrer, a thermometer, a gas inlet tube, and a constant pressure dropping funnel, and protected by nitrogen. The mixture was stirred at a temperature of 25°C and a stirring rate of 300 r / min for 20 min, and then the temperature was raised to 130°C to continue stirring for 20 min. Then, 40 mmol of pyrrole was added dropwise while stirring, and the dropping rate was controlled at 2 drops / s. After the addition was completed, the reaction was continued for 3 h. After the reaction, the reaction product was cooled to room temperature, and then poured into anhydrous methanol. After standing for 12 h, the filter cake was purified by silica gel column chromatography using a mixed solvent a of dichloromethane and n-hexane (5:1 by volume) to obtain chlorothiophenyl porphyrin; Step S5: 10 mmol of chlorothiophene porphyrin, 48 mmol of 2,2,6,6-tetramethylpiperidinamine, 70 mmol of anhydrous potassium carbonate, 60 mL of toluene and 100 mL of N,N-dimethylformamide were added into a three-necked flask equipped with a stirrer, a thermometer and a gas inlet tube, protected by nitrogen, stirred at a temperature of 25°C and a stirring rate of 300 r / min for 30 min, then stirred at a temperature of 70°C for 2 h, and then stirred at a temperature of 130°C for 5 h. After the reaction was completed, the reaction product was cooled to room temperature, then poured into ice water, vacuum filtered, and the filter cake was washed with anhydrous methanol for 5 times, then placed in a vacuum drying oven, dried at a temperature of 60°C for 4 h, and a hindered amine thiophene porphyrin was obtained; Step S6: 1 g of the hindered amine thiophene porphyrin, 3.5 g of nickel acetate tetrahydrate, 35 mL of acetic acid and 35 mL of chloroform were added into a three-necked flask equipped with a stirrer, a thermometer and a gas inlet tube, protected by nitrogen, stirred at a temperature of 25°C and a stirring rate of 300 r / min for 30 min, then stirred at a temperature of 120°C for 5 h. After the reaction was completed, the reaction product was cooled to room temperature, then rotary evaporated to remove the solvent, then poured into distilled water, vacuum filtered, and the filter cake was purified by silica gel column chromatography with a mixed solvent b of dichloromethane and petroleum ether in a volume ratio of 8:1, and a hindered amine thiophene metalloporphyrin was obtained; Step S7: low density polyethylene 75 parts, high density polyethylene 22 parts, ethylene-vinyl acetate copolymer 15 parts, polydopamine-coated titanium dioxide loaded whisker 11 parts, hindered amine thiophene metalloporphyrin 6.5 parts, calcium stearate 1.5 parts, vinyl bis-stearamide 0.9 parts and antioxidant 0.4 parts were weighed according to weight parts, and prepared for use. The low density polyethylene was LDPE Q281; the high density polyethylene was HDPE DMDA-8920; the ethylene-vinyl acetate copolymer was ELVAX 450; and the antioxidant was antioxidant 1010; Step S8: the low density polyethylene, high density polyethylene, ethylene-vinyl acetate copolymer, polydopamine-coated titanium dioxide loaded whisker, hindered amine thiophene metalloporphyrin, calcium stearate, vinyl bis-stearamide and antioxidant were added into a twin-screw extruder, melt extruded at a screw rotation speed of 60 r / min and five temperature zones of 170°C, 180°C, 190°C, 200°C and 195°C in sequence, water-cooled and granulated, and a geomembrane granule was obtained. Step S9: the geomembrane granule was cast into a film by a casting machine, and a high tensile anti-cracking geomembrane with a thickness of 1.5 mm was obtained.

[0030] Comparative Example 1: This comparative example was a preparation method of a high tensile anti-cracking geomembrane, comprising the following steps: Step S1: according to the weight part, low density polyethylene 75 parts, high density polyethylene 22 parts, ethylene-vinyl acetate copolymer 15 parts, calcium stearate 1.5 parts, vinyl bis stearyl amide 0.9 parts and antioxidant 0.4 parts, standby; the low density polyethylene is LDPE Q281; the high density polyethylene is HDPE DMDA-8920; the ethylene-vinyl acetate copolymer is ELVAX 450; the antioxidant is antioxidant 1010; Step S2: the low density polyethylene, high density polyethylene, ethylene-vinyl acetate copolymer, calcium stearate, vinyl bis stearyl amide and antioxidant are added into the double screw extruder, and are melt extruded under the conditions that the screw rotation speed is 60 r / min and the five temperature zones are 170℃, 180℃, 190℃, 200℃ and 195℃ in turn, and are water-cooled and granulated to obtain the geomembrane granules; Step S3: the geomembrane granules are cast into a film through a casting machine to obtain the high tensile anti-cracking geomembrane with a thickness of 1.5 mm.

[0031] Comparative Example 2: this comparative example is a preparation method of a high tensile anti-cracking geomembrane, comprising the following steps: Step S1: 3g of silicon carbide whiskers with an average diameter of 2μm and an average length of 45μm, 40mL of a 40% mass fraction nitric acid solution are added into a three-necked flask equipped with a stirrer and a thermometer, and stirred at a temperature of 25℃ and a stirring speed of 300r / min for 30min, then heated to 65℃ and stirred for 5h, after the reaction, the reaction product is cooled to room temperature, then centrifuged, and the precipitate is washed with anhydrous ethanol and distilled water for 5 times, then placed in a vacuum drying oven and dried at a temperature of 70℃ for 3h to obtain etched whiskers; Step S2: 5mL of tetrabutyl titanate, 2.5mL of a 38% mass fraction hydrochloric acid solution and 55mL of a 90% volume fraction ethanol solution are added into a reaction kettle, and stirred at a temperature of 45℃ and a stirring speed of 300r / min for 90min, then 5g of etched whiskers are added and heated to 160℃ for continuous stirring for 3h, after the reaction, the reaction product is cooled to room temperature, then centrifuged, and the precipitate is washed with anhydrous ethanol and distilled water for 5 times, then placed in a vacuum drying oven and dried at a temperature of 70℃ for 6h to obtain titanium dioxide loaded whiskers; Step S3: 2 g of titanium dioxide loaded whiskers, 15 mL of 27% ammonia water, 1.3 g of dopamine hydrochloride, and 45 mL of deionized water were added to a three-necked flask equipped with a stirrer and a thermometer, and stirred at a temperature of 25°C and a stirring rate of 300 r / min for 6 h. After the reaction was completed, the reaction product was centrifuged, the precipitate was washed with distilled water for 5 times, and then placed in a vacuum drying oven and dried at a temperature of 70°C for 3 h to obtain polydopamine coated titanium dioxide loaded whiskers; Step S4: low density polyethylene 75 parts, high density polyethylene 22 parts, ethylene-vinyl acetate copolymer 15 parts, polydopamine coated titanium dioxide loaded whiskers 11 parts, calcium stearate 1.5 parts, vinyl bis-stearamide 0.9 parts, and antioxidant 0.4 parts were weighed according to the weight parts, and prepared for use. The low density polyethylene was LDPE Q281; the high density polyethylene was HDPE DMAD-8920; the ethylene-vinyl acetate copolymer was ELVAX 450; and the antioxidant was antioxidant 1010; Step S5: The low density polyethylene, high density polyethylene, ethylene-vinyl acetate copolymer, polydopamine coated titanium dioxide loaded whiskers, calcium stearate, vinyl bis-stearamide, and antioxidant were added to a twin-screw extruder, and melt extruded at a screw rotation speed of 60 r / min and five temperature zones of 170°C, 180°C, 190°C, 200°C, and 195°C in sequence. After water cooling and granulation, geotextile granules were obtained. Step S6: The geotextile granules were cast into a film by a casting machine to obtain a high tensile and anti-cracking geotextile film with a thickness of 1.5 mm.

[0032] Comparative Example 3: This comparative example is a preparation method of a high tensile and anti-cracking geotextile film, comprising the following steps: Step S1: 40 mmol of 5-chlorothiophene-2-formaldehyde and 120 mL of glacial acetic acid were added to a three-necked flask equipped with a stirrer, a thermometer, a gas inlet tube, and a constant pressure dropping funnel, and protected by nitrogen. The reaction was stirred at a temperature of 25°C and a stirring rate of 300 r / min for 20 min, and then heated to 130°C and continued to stir for 20 min. Then 40 mmol of pyrrole was added dropwise while stirring, and the dropping rate was controlled at 2 drops / s. After the addition was completed, the reaction was continued to stir for 3 h. After the reaction was completed, the reaction product was cooled to room temperature, and then poured into anhydrous methanol. After standing for 12 h, the filter cake was purified by silica gel column chromatography with a mixed solvent a of dichloromethane and n-hexane (5:1 by volume) to obtain chlorothienyl porphyrin. Step S2: 10 mmol of chlorothiophene porphyrin, 48 mmol of 2,2,6,6-tetramethylpiperidinamine, 70 mmol of anhydrous potassium carbonate, 60 mL of toluene and 100 mL of N,N-dimethylformamide were added into a three-neck flask equipped with a stirrer, a thermometer and a gas inlet tube, protected by nitrogen, stirred at a temperature of 25℃ and a stirring rate of 300 r / min for 30 min, then stirred at a temperature of 70℃ for 2 h, and then stirred at a temperature of 130℃ for 5 h. After the reaction was completed, the reaction product was cooled to room temperature, then poured into ice water, vacuum filtered, and the filter cake was washed with anhydrous methanol for 5 times, then placed in a vacuum drying oven and dried at a temperature of 60℃ for 4 h to obtain a hindered amine thiophene porphyrin; Step S3: 1 g of hindered amine thiophene porphyrin, 3.5 g of nickel acetate tetrahydrate, 35 mL of acetic acid and 35 mL of chloroform were added into a three-neck flask equipped with a stirrer, a thermometer and a gas inlet tube, protected by nitrogen, stirred at a temperature of 25℃ and a stirring rate of 300 r / min for 30 min, then stirred at a temperature of 120℃ for 5 h. After the reaction was completed, the reaction product was cooled to room temperature, then rotary evaporation was performed to remove the solvent, then poured into distilled water, vacuum filtered, and the filter cake was purified by silica gel column chromatography with a mixed solvent b of dichloromethane and petroleum ether in a volume ratio of 8:1 to obtain a hindered amine thiophene metalloporphyrin; Step S4: low density polyethylene 75 parts, high density polyethylene 22 parts, ethylene-vinyl acetate copolymer 15 parts, hindered amine thiophene metalloporphyrin 6.5 parts, calcium stearate 1.5 parts, vinyl bis-stearamide 0.9 parts and antioxidant 0.4 parts were weighed according to the weight parts, and prepared for use. The low density polyethylene was LDPE Q281; the high density polyethylene was HDPE DMDA-8920; the ethylene-vinyl acetate copolymer was ELVAX 450; and the antioxidant was antioxidant 1010; Step S5: The low density polyethylene, high density polyethylene, ethylene-vinyl acetate copolymer, hindered amine thiophene metalloporphyrin, calcium stearate, vinyl bis-stearamide and antioxidant were added into a twin-screw extruder, and melt extruded under the conditions of a screw rotation speed of 60 r / min and five temperature zones of 170℃, 180℃, 190℃, 200℃ and 195℃ in sequence, and then water-cooled and granulated to obtain geomembrane granules. Step S6: The geomembrane granules were cast into a film by a casting machine to obtain a high tensile anti-cracking geomembrane with a thickness of 1.5 mm.

[0033] Comparative Example 4: This comparative example was a preparation method of a high tensile anti-cracking geomembrane, which included the following steps: Step S1: according to the weight parts, low density polyethylene 75 parts, high density polyethylene 22 parts, ethylene-vinyl acetate copolymer 15 parts, silicon carbide whisker 11 parts, 2,2,6,6-tetramethylpiperidine amine 6.5 parts, calcium stearate 1.5 parts, vinyl bis stearyl amide 0.9 parts and antioxidant 0.4 parts are weighed and prepared; the low density polyethylene is LDPE Q281; the high density polyethylene is HDPE DMDA-8920; the ethylene-vinyl acetate copolymer is ELVAX 450; the average diameter of the silicon carbide whisker is 2 μm, and the average length is 45 μm; the antioxidant is antioxidant 1010; Step S2: the low density polyethylene, high density polyethylene, ethylene-vinyl acetate copolymer, silicon carbide whisker, 2,2,6,6-tetramethylpiperidine amine, calcium stearate, vinyl bis stearyl amide and antioxidant are added into a double screw extruder, and are melt extruded under the conditions that the screw rotation speed is 60 r / min, and the five temperature zones are 170℃, 180℃, 190℃, 200℃ and 195℃ in sequence, and then are water cooled and granulated to obtain geotechnical membrane granules; Step S3: the geotechnical membrane granules are cast into a film through a casting machine to obtain a high tensile anti-cracking geotechnical membrane with a thickness of 1.5 mm.

[0034] Performance test: The high tensile anti-cracking geotechnical membranes of examples 1-3 and comparative examples 1-4 are tested for tensile strength according to GB / T 1040.3-2006, and the test results are shown in Figure 1 ; The high tensile anti-cracking geotechnical membranes of examples 1-3 and comparative examples 1-4 are irradiated under the conditions that the wavelength of the UVA-340 lamp tube is 340 nm, and the radiation intensity is 1.55 W / m 2 . Specifically, the cycle of 8 h ultraviolet light irradiation (irradiation temperature 60℃) and 4 h condensation (condensation temperature 50℃) is adopted, and the cycle is continuously operated for 120 h, 240 h, 360 h and 480 h respectively. Then the tensile strength is tested according to GB / T 1040.3-2006, and the tensile strength retention rate is calculated, the tensile strength retention rate = (tensile strength after irradiation treatment / tensile strength before irradiation treatment) x 100%, and the test results are shown in Figure 2 .

[0035] Referring to Figures 1-2 , it can be known from the comparison between examples 1-3 and comparative examples 1-4 that the addition of polydopamine coated titanium dioxide loaded whisker and hindered amine thienyl metal porphyrin can significantly improve the tensile strength and tensile strength retention rate of the high tensile anti-cracking geotechnical membrane, which indicates that the tensile anti-cracking performance and ultraviolet aging resistance of the geotechnical membrane of the application are excellent.

[0036] In the description of the specification, reference to terms "one embodiment", "an example", "a specific example" and so on is intended to indicate that a particular feature, structure, material or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the application. Descriptive expressions of the above terms in the specification do not necessarily refer to the same embodiment or example. Moreover, the described specific features, structures, materials or characteristics can be combined in any one or more embodiments or examples in a suitable manner.

[0037] The above is only an example and illustration of the application, and those skilled in the art can make various modifications or supplements to the described specific embodiments or replace them with similar ways, as long as they do not deviate from the application or exceed the scope defined in the application.

Claims

1. A high tensile, crack resistant geomembrane characterized by, Comprise the following components by weight parts: Low density polyethylene 70-75 parts, high density polyethylene 20-22 parts, ethylene-vinyl acetate copolymer 9-15 parts, polydopamine coated titanium dioxide loaded whisker 3-11 parts, hindered amine thiophene metal porphyrin 1.5-6.5 parts, calcium stearate 0.5-1.5 parts, vinyl bis stearic acid amide 0.3-0.9 parts and antioxidant 0.2-0.4 parts; Wherein, the polydopamine coated titanium dioxide loaded whisker is prepared by the following steps: Step a1: stirring reaction of silicon carbide whisker and nitric acid solution, cooling the reaction product after the reaction, then centrifugation, washing and drying the precipitate to obtain etched whisker; Step a2: stirring reaction of tetrabutyl titanate, hydrochloric acid solution and ethanol solution, then adding etched whisker to continue stirring reaction, cooling the reaction product after the reaction, then centrifugation, washing and drying the precipitate to obtain titanium dioxide loaded whisker; Step a3: stirring reaction of titanium dioxide loaded whisker, ammonia, dopamine hydrochloride and deionized water, centrifugation of the reaction product after the reaction, washing and drying the precipitate to obtain polydopamine coated titanium dioxide loaded whisker.

2. A high tensile crack resistant geomembrane according to claim 1, characterized in that, The amount ratio of silicon carbide whisker and nitric acid solution in step a1 is 3g:30-40mL; the average diameter of the silicon carbide whisker is 2μm, and the average length is 45μm; the mass fraction of the nitric acid solution is 30-40%.

3. A high tensile crack resistant geomembrane according to claim 1, characterized in that, The amount ratio of tetrabutyl titanate, hydrochloric acid solution, ethanol solution and etched whisker in step a2 is 2-5mL:2-2.5mL:50-55mL:5g; the mass fraction of the hydrochloric acid solution is 36-38%; the volume fraction of the ethanol solution is 80-90%.

4. The high tensile crack resistant geomembrane according to claim 1, wherein, The amount ratio of titanium dioxide loaded whisker, ammonia, dopamine hydrochloride and deionized water in step a3 is 2g:10-15mL:0.5-1.3g:40-45mL; the mass fraction of the ammonia is 25-27%.

5. A high tensile crack resistant geomembrane according to claim 1, wherein The hindered amine thiophene metal porphyrin is prepared by the following steps: Step b1: stirring reaction of 5-chlorothiophene-2-formaldehyde and glacial acetic acid, then dropwise adding pyrrole to continue stirring reaction, cooling the reaction product after the reaction, then pouring into anhydrous methanol and standing, then vacuum filtration, and silica gel column chromatography purification of the filter cake with mixed solvent a to obtain chlorothiophene porphyrin; Step b2: stirring reaction of chlorothiophene porphyrin, 2,2,6,6-tetramethylpiperidinamine, anhydrous potassium carbonate, toluene and N,N-dimethylformamide, cooling the reaction product after the reaction, then pouring into ice water, then vacuum filtration, and washing and drying the filter cake to obtain hindered amine thiophene porphyrin; Step b3: stirring reaction of hindered amine thiophene porphyrin, nickel acetate tetrahydrate, acetic acid and chloroform, cooling the reaction product after the reaction, then rotary evaporation, then pouring into distilled water, then vacuum filtration, and silica gel column chromatography purification of the filter cake with mixed solvent b to obtain hindered amine thiophene metal porphyrin.

6. A high tensile, crack resistant geomembrane according to claim 5, wherein, The amount ratio of the 5-chlorothiophene-2-formaldehyde, glacial acetic acid and pyrrole in step b1 is 40 mmol: 100-120 mL: 40 mmol; the mixed solvent a is a mixture of dichloromethane and n-hexane in a volume ratio of 3-5:

1.

7. A high tensile crack resistant geomembrane according to claim 5, wherein The amount ratio of the chlorothiophenyl porphyrin, 2,2,6,6-tetramethylpiperidinamine, anhydrous potassium carbonate, toluene and N,N-dimethylformamide in step b2 is 10 mmol: 44-48 mmol: 60-70 mmol: 50-60 mL: 90-100 mL.

8. A high tensile crack resistant geomembrane according to claim 5, wherein, The amount ratio of the hindered amine thiophenyl porphyrin, nickel acetate tetrahydrate, acetic acid and chloroform in step b3 is 1 g: 3-3.5 g: 30-35 mL: 30-35 mL; the mixed solvent b is a mixture of dichloromethane and petroleum ether in a volume ratio of 7-8:

1.

9. A method of manufacturing a high tensile crack resistant geomembrane according to any one of claims 1 to 8, characterised in that, The method comprises the following steps: Step one: low-density polyethylene 70-75 parts, high-density polyethylene 20-22 parts, ethylene-vinyl acetate copolymer 9-15 parts, polydopamine-coated titanium dioxide loaded whisker 3-11 parts, hindered amine thiophenyl metalloporphyrin 1.5-6.5 parts, calcium stearate 0.5-1.5 parts, vinyl bis-stearamide 0.3-0.9 parts and antioxidant 0.2-0.4 parts are weighed according to weight parts and prepared; Step two: the low-density polyethylene, high-density polyethylene, ethylene-vinyl acetate copolymer, polydopamine-coated titanium dioxide loaded whisker, hindered amine thiophenyl metalloporphyrin, calcium stearate, vinyl bis-stearamide and antioxidant are added into a twin-screw extruder, and are melt-extruded under the conditions that the screw rotation speed is 30-60 r / min and the five temperature zones are 160-170 °C, 170-180 °C, 180-190 °C, 190-200 °C and 185-195 °C in sequence, and then are water-cooled and granulated to obtain geotechnical membrane granules; Step three: the geotechnical membrane granules are cast into a film through a casting machine to obtain a high-tensile anti-cracking geotechnical membrane.

10. A method of making a high tensile, crack resistant geomembrane according to claim 9, characterized in that, The low-density polyethylene is LDPE Q281; The high-density polyethylene is HDPE DMDA-8920; The ethylene-vinyl acetate copolymer is ELVAX 450; The antioxidant is antioxidant 1010.

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