Environment-friendly polyurethane elastomer well site cofferdam

Abstract

The environment-friendly polyurethane elastomer well site cofferdam is prepared from the following components in parts by weight: 60 to 65 parts of matrix polyurethane resin, 15 to 18 parts of chain extender, 6 to 8 parts of plasticizer and 10 to 15 parts of tea polyphenol-dimethylglyoxime type polyurethane resin coating. The well site cofferdam prepared by the technical scheme of the invention has excellent corrosion resistance and tensile property.

Description

Technical Field

[0001] This invention belongs to the field of elastomer technology, specifically relating to an environmentally friendly polyurethane elastomer well site cofferdam. Background Technology

[0002] Oilfield well site cofferdams are environmental protection devices used to collect and isolate oily wastewater generated during operations and prevent the spread of pollutants. They are generally made of metal or composite materials, replacing traditional impermeable membranes, and can be reused to reduce the generation of solid waste.

[0003] Currently, fiberglass products are frequently chosen as cofferdam materials. However, fiberglass cofferdams have two main drawbacks: firstly, they are expensive to manufacture; secondly, although fiberglass has high structural strength, it is also quite brittle, making it prone to cracking during use, leading to sewage leakage, pollution, and increased treatment costs.

[0004] Compared to fiberglass well site cofferdams, polyurethane elastomer well site cofferdams have lower maintenance costs and are more impact-resistant over long-term use. They can also be customized and spliced ​​according to specific needs. However, polyurethane elastomer well site cofferdams are still lacking in resistance to acid and alkali corrosion. Therefore, improvements are needed to meet the requirements of polyurethane elastomer well site cofferdams. Summary of the Invention

[0005] (a) Technical problems to be solved

[0006] To address the shortcomings of existing technologies, this invention provides an environmentally friendly polyurethane elastomer well site cofferdam.

[0007] (II) Technical Solution

[0008] To achieve the above objectives, the present invention provides the following technical solution:

[0009] An environmentally friendly polyurethane elastomer well site cofferdam, by weight, comprises 60-65 parts of matrix polyurethane resin, 15-18 parts of chain extender, 6-8 parts of plasticizer, and 10-15 parts of tea polyphenol-butanedione oxime type polyurethane resin coating.

[0010] Furthermore, the preparation method of the tea polyphenol-butanedione oxime type polyurethane resin coating is as follows:

[0011] S1: Dissolve 0.5 parts by weight of tea polyphenols in distilled water by stirring, and add 0.8 mol·L⁻¹. -1 The lanthanum chloride solution was mixed evenly, and the pH was adjusted to 6-8 with sodium hydroxide solution. The mixture was heated at room temperature for 1-2 hours. After centrifugation, washing and drying, the tea polyphenol pretreatment product was obtained. A chitosan-glacial acetic acid solution with a chitosan concentration of 0.1-0.15% was prepared, and the tea polyphenol pretreatment product was added. The mixture was stirred evenly to obtain the tea polyphenol-chitosan modified product.

[0012] S2: By weight, disperse 1-2 parts of nano-silica in water and stir evenly, add 10-12 parts of pretreated plant fiber, add 2-3 parts of 2-chloroethanethiol, heat to 65-70℃, react for 1 hour, cool, filter, and dry to obtain silica-modified plant fiber.

[0013] S3: By weight, 7-7.5 parts of polytetrahydrofuran diol, 2-2.5 parts of isophorone diisocyanate, 2-2.5 parts of dimethylglyoxime, 0.1-0.3 parts of dibutyltin dilaurate, and 0.8-1 parts of hydroxyethyl acrylate are reacted at 80°C for 2 hours. Then, 0.6-0.8 parts of trimethylolpropane and 2-2.5 parts of dimethylglyoxime are added for crosslinking. The temperature is lowered to 50°C, and 3-5 parts of silica-modified plant fiber, 0.1-0.15 parts of benzoin dimethyl ether, and 0.2-0.25 parts of p-toluenesulfonic acid are added. The mixture is stirred rapidly and evenly at high speed. It is then irradiated with a 365nm LED (15mW cm⁻²) for 10-12 minutes while stirring at 200-250 rpm. The light source is turned off, and the mixture is cured at 50°C for 1 hour. Finally, it is vacuum dried to obtain the modified dimethylglyoxime type polyurethane resin.

[0014] S4: By weight, add 4-5 parts of tea polyphenol-chitosan modified material and 8-10 parts of modified dimethylglyoxime type polyurethane resin to a high-speed mixer and mix at 200-220℃ for 10-15 minutes to obtain tea polyphenol-dimethylglyoxime type polyurethane resin coated material.

[0015] Furthermore, the mass ratio of lanthanum chloride to tea polyphenols is 1:1-2.

[0016] Furthermore, the mass fraction of the glacial acetic acid solution is 1-3%.

[0017] Furthermore, the preparation method of the pretreated plant fiber is as follows: by weight, take 20-25 parts of bamboo fiber, degummed by alkali boiling, dried, add N,N-dimethylformamide, stir and heat to 80°C, maintain for 1-1.5h, add 3-5 parts of maleic anhydride and 0.3-0.4 parts of benzoyl peroxide, stir evenly, heat to 90°C under nitrogen atmosphere, 4-5h, cool to room temperature, wash with ethanol, filter, and dry to obtain pretreated plant fiber.

[0018] Furthermore, the method for preparing the polyurethane elastomer well site cofferdam is as follows:

[0019] A1; By weight, 80-85 parts of polyether polyol are dehydrated at 100-110℃, cooled to 40-50℃, 60-80 parts of diisocyanate are added, and reacted at 80-85℃ for 2-2.5h under nitrogen atmosphere to obtain the matrix polyurethane resin. Tea polyphenol-butanedione oxime type polyurethane resin coating is added and stirred at 80-85℃ for 2h. Vacuum degassing is performed, and the material is cooled and discharged to obtain polyurethane elastomer prepolymer.

[0020] A2: Mix the polyurethane elastomer prepolymer, chain extender and plasticizer evenly, degas, put it into a mold and cold press to form an elastomer well site cofferdam.

[0021] Furthermore, the polyether polyol is at least one of polytetrahydrofuran diol, polyethylene glycol, polypropylene glycol, and polyepoxypropylene polyol, with a number average molecular weight of 2000-3000.

[0022] Furthermore, the diisocyanate includes one or more of 1,6-hexamethylene diisocyanate, triisocyanate nonane, toluene diisocyanate (TDI), diphenylmethane diisocyanate (MDI), and isophorone diisocyanate.

[0023] Furthermore, the chain extender is one or more of di-o-chloroanilinemethane, dimethylthiotoluenediamine, diethyltoluenediamine, 2,4-diamino-3,5-dimethylthiochlorobenzene, and 2,4-diamino-3-methylthio-5-propylchlorobenzene.

[0024] Furthermore, the plasticizer is at least one selected from dioctyl adipate, dioctyl sebacate, toluene diphenyl phosphate, diphenyl isodecanyl phosphate, and tributyl acetylcitrate.

[0025] By adopting the above technical solution, the present invention has the following beneficial effects compared with the prior art:

[0026] 1. In the technical solution of this invention, the preparation of modified dimethylglyoxime polyurethane resin involves introducing oxime-urethane bonds via dimethylglyoxime. In this invention, the surface of plant cellulose is connected to silica via maleic anhydride. The carbon-carbon double bonds on the maleic anhydride surface undergo thiol-ene clicks, introducing thiol groups into the silica surface. These thiol groups then form thiol-ene-oxime bonds with the oxime-urethane in the dimethylglyoxime polyurethane resin, enhancing its mechanical properties and corrosion resistance.

[0027] 2. This invention introduces the rare earth element lanthanum onto the surface of tea polyphenols to enhance their corrosion resistance. Then, chitosan is used to modify the tea polyphenols, enhancing their compatibility with dimethylglyoxime-type polyurethane resins. Furthermore, in an acidic environment, the channels of chitosan are opened, allowing lanthanum ions on the tea polyphenols to detach and chelate with dimethylglyoxime to form a dense protective film, thereby enhancing its corrosion resistance and mechanical properties. Detailed Implementation

[0028] The technical solutions of this invention will be clearly and completely described below with reference to the embodiments thereof. Obviously, the described embodiments are only some embodiments of this invention, and not all embodiments. The following description of at least one exemplary embodiment is merely illustrative and is in no way intended to limit this invention or its application or use. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without creative effort are within the scope of protection of this invention.

[0029] Example 1

[0030] This embodiment prepares an environmentally friendly polyurethane elastomer well site cofferdam, which, by weight, comprises 65 parts of matrix polyurethane resin, 16.5 parts of chain extender, 7 parts of plasticizer, and 13 parts of tea polyphenol-butanedione oxime type polyurethane resin coating.

[0031] The preparation method of the pretreated plant fiber in the polyphenol-dimethylglyoxime type polyurethane resin coating in this embodiment is as follows: 23 parts by weight of bamboo fiber were degummed by alkali boiling and dried. N,N-dimethylformamide was added, stirred and heated to 80°C, and maintained for 1.5 h. 4 parts of maleic anhydride and 0.35 parts of benzoyl peroxide were added and stirred evenly. The temperature was raised to 90°C under a nitrogen atmosphere for 5 h. After cooling to room temperature, the fiber was washed with ethanol, filtered, and dried to obtain the pretreated plant fiber.

[0032] The preparation method of the tea polyphenol-butanedione oxime type polyurethane resin coating in this embodiment is as follows:

[0033] S1: Dissolve 0.5 parts by weight of tea polyphenols in distilled water by stirring, and add 0.8 mol·L⁻¹. -1 The lanthanum chloride solution was mixed evenly, and the pH was adjusted to 6-8 with sodium hydroxide solution. The mixture was heated at room temperature for 1.5 h. After centrifugation, washing, and drying, the tea polyphenol pretreated product was obtained. A chitosan-glacial acetic acid solution with a chitosan concentration of 0.13% was prepared, and the tea polyphenol pretreated product was added. The mixture was stirred evenly to obtain the tea polyphenol-chitosan modified product. The mass ratio of lanthanum chloride to tea polyphenols was 1:1.5, and the mass fraction of the glacial acetic acid solution was 2%.

[0034] S2: By weight, 1.5 parts of nano silica were dispersed in water and stirred evenly, 11 parts of pretreated plant fiber were added, 2.5 parts of 2-chloroethanethiol were added, the temperature was raised to 65°C, the reaction was carried out for 1 hour, cooled, filtered, and dried to obtain mercapto silica-modified plant fiber.

[0035] S3: By weight, 7.3 parts of polytetrahydrofuran diol, 2.25 parts of isophorone diisocyanate, 2.25 parts of dimethylglyoxime, 0.2 parts of dibutyltin dilaurate, and 0.8-1 parts of hydroxyethyl acrylate were reacted at 80°C for 2 hours. Then, 0.7 parts of trimethylolpropane and 2.3 parts of dimethylglyoxime were added for crosslinking. The temperature was lowered to 50°C, and 4 parts of silica-modified plant fiber, 0.13 parts of benzoin dimethyl ether, and 0.23 parts of p-toluenesulfonic acid were added. The mixture was stirred rapidly and evenly at high speed. It was irradiated with a 365nm LED (15mW cm⁻²) for 11 minutes while stirring at 225 rpm. The light source was turned off, and the mixture was cured at 50°C for 1 hour. The mixture was then vacuum dried to obtain the modified dimethylglyoxime type polyurethane resin.

[0036] S4: By weight, 4.5 parts of tea polyphenol-chitosan modified material and 9 parts of modified dimethylglyoxime polyurethane resin were added to a high-speed mixer and mixed at 210°C for 13 minutes to obtain tea polyphenol-dimethylglyoxime polyurethane resin coated material.

[0037] The method for preparing the polyurethane elastomer well site cofferdam in this embodiment is as follows:

[0038] A1; By weight, 82.5 parts of polytetrahydrofuran diol with a number average molecular weight of 2500 were dehydrated at 105°C, cooled to 45°C, and 70 parts of 1,6-hexamethylene diisocyanate were added. The mixture was reacted at 85°C for 2.3 hours under a nitrogen atmosphere to obtain the matrix polyurethane resin. A tea polyphenol-butanedione oxime type polyurethane resin coating was added and stirred at 85°C for 2 hours. The mixture was then degassed under vacuum and cooled to obtain the polyurethane elastomer prepolymer.

[0039] A2: Mix polyurethane elastomer prepolymer, di-o-chloroaniline methane and dioctyl adipate evenly, degas, place in a mold and cold press to form an elastomer well site cofferdam.

[0040] Example 2

[0041] This embodiment prepares an environmentally friendly polyurethane elastomer well site cofferdam, which, by weight, comprises 60 parts of matrix polyurethane resin, 15 parts of chain extender, 6 parts of plasticizer, and 10 parts of tea polyphenol-butanedione oxime type polyurethane resin coating.

[0042] The preparation method of the pretreated plant fiber in the polyphenol-dimethylglyoxime type polyurethane resin coating in this embodiment is as follows: 20 parts by weight of bamboo fiber were degummed by alkali boiling and dried. N,N-dimethylformamide was added, stirred and heated to 80°C, and kept for 1 hour. 3 parts of maleic anhydride and 0.3 parts of benzoyl peroxide were added and stirred evenly. The temperature was raised to 90°C under a nitrogen atmosphere for 4 hours. After cooling to room temperature, the fibers were washed with ethanol, filtered, and dried to obtain the pretreated plant fiber.

[0043] The preparation method of the tea polyphenol-butanedione oxime type polyurethane resin coating in this embodiment is as follows:

[0044] S1: Dissolve 0.5 parts by weight of tea polyphenols in distilled water by stirring, and add 0.8 mol·L⁻¹. -1 The lanthanum chloride solution was mixed evenly, and the pH was adjusted to 6 with sodium hydroxide solution. The mixture was heated at room temperature for 1 hour. After centrifugation, washing, and drying, the tea polyphenol pretreated product was obtained. A chitosan-glacial acetic acid solution with a chitosan concentration of 0.1% was prepared, and the tea polyphenol pretreated product was added. The mixture was stirred evenly to obtain the tea polyphenol-chitosan modified product. The mass ratio of lanthanum chloride to tea polyphenols was 1:1, and the mass fraction of the glacial acetic acid solution was 1%.

[0045] S2: By weight, 1 part of nano silica is dispersed in water and stirred evenly, 10 parts of pretreated plant fiber are added, 2 parts of 2-chloroethanethiol are added, the temperature is raised to 65°C, the reaction is carried out for 1 hour, cooled, filtered, and dried to obtain mercapto silica-modified plant fiber.

[0046] S3: By weight, 7 parts polytetrahydrofuran diol, 2 parts isophorone diisocyanate, 2 parts dimethylglyoxime, 0.1 parts dibutyltin dilaurate and 0.8 parts hydroxyethyl acrylate were reacted at 80°C for 2 hours. 0.6 parts trimethylolpropane and 2 parts dimethylglyoxime were added for crosslinking reaction. The temperature was lowered to 50°C, and 3 parts silica-modified plant fiber, 0.1 parts benzoin dimethyl ether and 0.2 parts p-toluenesulfonic acid were added. The mixture was stirred rapidly and evenly at high speed. It was irradiated with a 365nm LED (15mW cm⁻²) for 10 minutes while stirring at 200rpm. The light source was turned off, and the mixture was cured at 50°C for 1 hour. The modified dimethylglyoxime type polyurethane resin was obtained by vacuum drying.

[0047] S4: By weight, add 4 parts of tea polyphenol-chitosan modified material and 8 parts of modified dimethylglyoxime polyurethane resin to a high-speed mixer and mix at 200°C for 10 minutes to obtain tea polyphenol-dimethylglyoxime polyurethane resin coated material.

[0048] The method for preparing the polyurethane elastomer well site cofferdam in this embodiment is as follows:

[0049] A1; By weight, 80 parts of polyethylene glycol with a number average molecular weight of 2000 were dehydrated at 100°C, cooled to 40°C, and 60 parts of triisocyanate nonane were added. The mixture was reacted at 80°C for 2 hours under a nitrogen atmosphere to obtain the matrix polyurethane resin. The tea polyphenol-butanedione oxime type polyurethane resin coating was added and stirred at 80°C for 2 hours. The mixture was then degassed under vacuum and cooled to obtain the polyurethane elastomer prepolymer.

[0050] A2: Mix polyurethane elastomer prepolymer, dimethyl thiotoluene diamine and dioctyl sebacate evenly, degas, place in a mold and cold press to form an elastomer well site cofferdam.

[0051] Example 3

[0052] This embodiment prepares an environmentally friendly polyurethane elastomer well site cofferdam, which, by weight, comprises 65 parts of matrix polyurethane resin, 18 parts of chain extender, 8 parts of plasticizer, and 15 parts of tea polyphenol-butanedione oxime type polyurethane resin coating.

[0053] The preparation method of the pretreated plant fiber in the tea polyphenol-dimethylglyoxime type polyurethane resin coating in this embodiment is as follows: 25 parts by weight of bamboo fiber were degummed by alkali boiling and dried. N,N-dimethylformamide was added, stirred and heated to 80°C, and maintained for 1.5 h. 5 parts of maleic anhydride and 0.4 parts of benzoyl peroxide were added and stirred evenly. The temperature was raised to 90°C under a nitrogen atmosphere for 5 h. After cooling to room temperature, the fiber was washed with ethanol, filtered, and dried to obtain the pretreated plant fiber.

[0054] The preparation method of the tea polyphenol-butanedione oxime type polyurethane resin coating in this embodiment is as follows:

[0055] S1: Dissolve 0.5 parts by weight of tea polyphenols in distilled water by stirring, and add 0.8 mol·L⁻¹. -1 The lanthanum chloride solution was mixed evenly, and the pH was adjusted to 8 with sodium hydroxide solution. The mixture was heated at room temperature for 2 hours. After centrifugation, washing, and drying, the tea polyphenol pretreated product was obtained. A chitosan-glacial acetic acid solution with a chitosan concentration of 0.15% was prepared, and the tea polyphenol pretreated product was added. The mixture was stirred evenly to obtain the tea polyphenol-chitosan modified product. The mass ratio of lanthanum chloride to tea polyphenols was 1:2, and the mass fraction of the glacial acetic acid solution was 3%.

[0056] S2: By weight, 2 parts of nano silica were dispersed in water and stirred evenly, 12 parts of pretreated plant fiber were added, 3 parts of 2-chloroethanethiol were added, the temperature was raised to 70°C, the reaction was carried out for 1 hour, cooled, filtered, and dried to obtain mercapto silica-modified plant fiber.

[0057] S3: By weight, 7.5 parts of polytetrahydrofuran diol, 2.5 parts of isophorone diisocyanate, 2.5 parts of dimethylglyoxime, 0.3 parts of dibutyltin dilaurate and 1 part of hydroxyethyl acrylate were reacted at 80°C for 2 hours. Then, 0.8 parts of trimethylolpropane and 2.5 parts of dimethylglyoxime were added for crosslinking reaction. The temperature was lowered to 50°C, and 5 parts of silica-modified plant fiber, 0.15 parts of benzoin dimethyl ether and 0.25 parts of p-toluenesulfonic acid were added. The mixture was stirred rapidly and evenly at high speed. It was irradiated with a 365nm LED (15mW cm⁻²) for 12 minutes while stirring at 250rpm. The light source was turned off, and the mixture was cured at 50°C for 1 hour. The modified dimethylglyoxime type polyurethane resin was obtained by vacuum drying.

[0058] S4: By weight, 5 parts of tea polyphenol-chitosan modified material and 10 parts of modified dimethylglyoxime polyurethane resin were added to a high-speed mixer and mixed at 220°C for 15 minutes to obtain tea polyphenol-dimethylglyoxime polyurethane resin coated material.

[0059] The method for preparing the polyurethane elastomer well site cofferdam in this embodiment is as follows:

[0060] A1; By weight, 85 parts of polypropylene glycol with a number average molecular weight of 3000 were dehydrated at 110°C, cooled to 50°C, and 80 parts of toluene diisocyanate (TDI) were added. The mixture was reacted at 85°C for 2.5 hours under a nitrogen atmosphere to obtain the matrix polyurethane resin. The polyphenol-butanedione oxime type polyurethane resin coating was added and stirred at 85°C for 2 hours. The mixture was then degassed under vacuum and cooled to obtain the polyurethane elastomer prepolymer.

[0061] A2: Mix polyurethane elastomer prepolymer, diethyltoluene diamine and toluene diphenyl phosphate evenly, degas, place in a mold and cold press to form an elastomer well site cofferdam.

[0062] Example 4

[0063] This embodiment prepares an environmentally friendly polyurethane elastomer well site cofferdam, which, by weight, comprises 61 parts of matrix polyurethane resin, 16 parts of chain extender, 6.5 parts of plasticizer, and 12 parts of tea polyphenol-butanedione oxime type polyurethane resin coating.

[0064] The preparation method of the pretreated plant fiber in the polyphenol-dimethylglyoxime type polyurethane resin coating in this embodiment is as follows: 22 parts by weight of bamboo fiber were degummed by alkali boiling and dried. N,N-dimethylformamide was added, stirred and heated to 80°C, and maintained for 1.2 h. 3.5 parts of maleic anhydride and 0.32 parts of benzoyl peroxide were added and stirred evenly. The temperature was raised to 90°C under a nitrogen atmosphere for 4.2 h. After cooling to room temperature, the fiber was washed with ethanol, filtered, and dried to obtain the pretreated plant fiber.

[0065] The preparation method of the tea polyphenol-butanedione oxime type polyurethane resin coating in this embodiment is as follows:

[0066] S1: Dissolve 0.5 parts by weight of tea polyphenols in distilled water by stirring, and add 0.8 mol·L⁻¹. -1 The lanthanum chloride solution was mixed evenly, and the pH was adjusted to 6.5 with sodium hydroxide solution. The mixture was heated at room temperature for 1.2 h. After centrifugation, washing, and drying, the tea polyphenol pretreated product was obtained. A chitosan-glacial acetic acid solution with a chitosan concentration of 0.12% was prepared, and the tea polyphenol pretreated product was added. The mixture was stirred evenly to obtain the tea polyphenol-chitosan modified product. The mass ratio of lanthanum chloride to tea polyphenols was 1:1.2, and the mass fraction of the glacial acetic acid solution was 1.5%.

[0067] S2: By weight, 1.2 parts of nano-silica are dispersed in water and stirred evenly, 10-12 parts of pretreated plant fiber are added, 2.3 parts of 2-chloroethanethiol are added, the temperature is raised to 66°C, the reaction is carried out for 1 hour, cooled, filtered, and dried to obtain mercaptosilica-modified plant fiber.

[0068] S3: By weight, 7.2 parts of polytetrahydrofuran diol, 2.2 parts of isophorone diisocyanate, 2.2 parts of dimethylglyoxime, 0.15 parts of dibutyltin dilaurate and 0.85 parts of hydroxyethyl acrylate were reacted at 80°C for 2 hours. Then, 0.65 parts of trimethylolpropane and 2.2 parts of dimethylglyoxime were added for crosslinking reaction. The temperature was lowered to 50°C, and 3.5 parts of silica-modified plant fiber, 0.12 parts of benzoin dimethyl ether and 0.22 parts of p-toluenesulfonic acid were added. The mixture was stirred rapidly and evenly at high speed. It was irradiated with a 365nm LED (15mW cm⁻²) for 10.5 minutes while stirring at 210 rpm. The light source was turned off, and the mixture was cured at 50°C for 1 hour. The mixture was then vacuum dried to obtain the modified dimethylglyoxime type polyurethane resin.

[0069] S4: By weight, 4.2 parts of tea polyphenol-chitosan modified material and 8.3 parts of modified dimethylglyoxime type polyurethane resin were added to a high-speed mixer and mixed at 205°C for 12 minutes to obtain tea polyphenol-dimethylglyoxime type polyurethane resin coated material.

[0070] The method for preparing the polyurethane elastomer well site cofferdam in this embodiment is as follows:

[0071] A1; By weight, 83 parts of polyepoxypropylene polyol with a number average molecular weight of 2200 were dehydrated at 103°C, cooled to 42°C, and 65 parts of diphenylmethane diisocyanate were added. The mixture was reacted at 82°C for 2.2 h under a nitrogen atmosphere to obtain the matrix polyurethane resin. Tea polyphenol-butanedione oxime type polyurethane resin coating was added and stirred at 82°C for 2 h. The mixture was then degassed under vacuum and cooled to obtain the polyurethane elastomer prepolymer.

[0072] A2: Mix polyurethane elastomer prepolymer, 2,4-diamino-3,5-dimethylthiochlorobenzene and diphenylisodecyl phosphate evenly, degas, place in a mold and cold press to form an elastomer well site cofferdam.

[0073] Example 5

[0074] This embodiment prepares an environmentally friendly polyurethane elastomer well site cofferdam, which, by weight, comprises 64 parts of matrix polyurethane resin, 17 parts of chain extender, 7.5 parts of plasticizer, and 14 parts of tea polyphenol-butanedione oxime type polyurethane resin coating.

[0075] The preparation method of the pretreated plant fiber in the polyphenol-dimethyl oxime type polyurethane resin coating in this embodiment is as follows: 24 parts by weight of bamboo fiber were degummed by alkali boiling and dried. N,N-dimethylformamide was added, stirred and heated to 80°C, and maintained for 1.4 h. 4.5 parts of maleic anhydride and 0.38 parts of benzoyl peroxide were added and stirred evenly. The temperature was raised to 90°C under a nitrogen atmosphere for 4.8 h. After cooling to room temperature, the fiber was washed with ethanol, filtered, and dried to obtain the pretreated plant fiber.

[0076] The preparation method of the tea polyphenol-butanedione oxime type polyurethane resin coating in this embodiment is as follows:

[0077] S1: Dissolve 0.5 parts by weight of tea polyphenols in distilled water by stirring, and add 0.8 mol·L⁻¹. -1 The lanthanum chloride solution was mixed evenly, and the pH was adjusted to 8 with sodium hydroxide solution. The mixture was heated at room temperature for 1.8 h. After centrifugation, washing, and drying, the tea polyphenol pretreated product was obtained. A chitosan-glacial acetic acid solution with a chitosan concentration of 0.14% was prepared, and the tea polyphenol pretreated product was added. The mixture was stirred evenly to obtain the tea polyphenol-chitosan modified product. The mass ratio of lanthanum chloride to tea polyphenol was 1:1.8, and the mass fraction of the glacial acetic acid solution was 2.5%.

[0078] S2: By weight, 1.8 parts of nano silica were dispersed in water and stirred evenly, 11.5 parts of pretreated plant fiber were added, and 2.8 parts of 2-chloroethanethiol were added. The temperature was raised to 68°C and reacted for 1 hour. After cooling, filtration and drying were performed to obtain mercapto silica-modified plant fiber.

[0079] S3: By weight, 7.4 parts of polytetrahydrofuran diol, 2.4 parts of isophorone diisocyanate, 2.4 parts of dimethylglyoxime, 0.25 parts of dibutyltin dilaurate and 0.95 parts of hydroxyethyl acrylate were reacted at 80°C for 2 hours. Then, 0.75 parts of trimethylolpropane and 2.4 parts of dimethylglyoxime were added for crosslinking reaction. The temperature was lowered to 50°C, and 4.5 parts of silica-modified plant fiber, 0.14 parts of benzoin dimethyl ether and 0.24 parts of p-toluenesulfonic acid were added. The mixture was stirred rapidly and evenly at high speed. It was irradiated with a 365nm LED (15mW cm⁻²) for 11.5 minutes while stirring at 240 rpm. The light source was turned off, and the mixture was cured at 50°C for 1 hour. The mixture was then vacuum dried to obtain the modified dimethylglyoxime type polyurethane resin.

[0080] S4: By weight, 4.8 parts of tea polyphenol-chitosan modified material and 9.5 parts of modified dimethylglyoxime polyurethane resin were added to a high-speed mixer and mixed at 215°C for 14 minutes to obtain tea polyphenol-dimethylglyoxime polyurethane resin coated material.

[0081] The method for preparing the polyurethane elastomer well site cofferdam in this embodiment is as follows:

[0082] A1; By weight, 84 parts of polyether polyol with a number average molecular weight of 2800 were dehydrated at 108°C, cooled to 48°C, and 75 parts of isophorone diisocyanate were added. The mixture was reacted at 84°C for 2.4 h under a nitrogen atmosphere to obtain the matrix polyurethane resin. A tea polyphenol-butanedione oxime type polyurethane resin coating was added and stirred at 84°C for 2 h. The mixture was degassed under vacuum and cooled to obtain a polyurethane elastomer prepolymer. The polyether polyol was a mixture of polytetrahydrofuran glycol, polyethylene glycol, polypropylene glycol and polyepoxypropylene polyol in a mass ratio of 1:1.

[0083] A2: Mix polyurethane elastomer prepolymer, 2,4-diamino-3-methylthio-5-propylchlorobenzene and tri-n-butyl acetyl citrate evenly, degas, place in a mold and cold press to form an elastomer well site cofferdam.

[0084] The difference between Comparative Example 1 and Example 1 is that lanthanum nitrate was not added in the preparation of the tea polyphenol-chitosan modified product in Comparative Example 1.

[0085] The difference between Comparative Example 2 and Example 1 is that in Comparative Example 2, the mercaptosilica-modified plant fiber is replaced with silica-modified plant fiber; that is, 2-chloroethanethiol is not added in its preparation.

[0086] The difference between Comparative Example 3 and Example 1 is that lanthanum nitrate was not added in the preparation of the tea polyphenol-chitosan modified product in Comparative Example 3, and the mercapto silica modified plant fiber was replaced with silica modified plant fiber.

[0087] The difference between Comparative Example 4 and Example 1 is that the dimethylglyoxime type polyurethane resin was replaced with polyurethane resin in Comparative Example 4; that is, dimethylglyoxime was not added in its preparation.

[0088] The tensile strength of the well site cofferdam prepared according to the present invention was determined in accordance with GB / T528-2009, and the results are shown in Table 1.

[0089] The composite material samples were soaked in 80wt% sulfuric acid for 24 hours. The unnotched impact strength of the composite material before and after soaking was tested according to ISO179-1:2010. The corrosion resistance was compared by calculating the loss rate. The results are shown in Table 1.

[0090] Table 1

[0091] Tensile strength (MPa) Quality loss rate (%) Example 1 36.7 3.2 Example 2 36.4 3.7 Example 3 36.2 3.5 Example 4 36.5 3.8 Example 5 36.3 3.5 Comparative Example 1 32.3 5.2 Comparative Example 2 30.1 5.5 Comparative Example 3 25.8 5.9 Comparative Example 4 25.4 5.7

[0092] In conjunction with Examples 1-5 and Table 1, the flame-retardant plastic prepared by the technical solution of the present invention has excellent tensile strength and corrosion resistance.

[0093] Based on the data from Example 1, Comparative Example 1, and Table 1, it can be seen that the addition of lanthanum in the preparation of tea polyphenol-chitosan modified material can improve the tensile strength and corrosion resistance of the prepared well site cofferdam.

[0094] Based on the data from Example 1, Comparative Example 2, and Table 1, it can be seen that the corrosion resistance and tensile strength of the prepared well site cofferdam are significantly increased due to the introduction of mercapto groups on the silica surface in the silica-modified plant fiber.

[0095] Based on the data from Examples 1, 1, 2, 3, and 4, and Table 1, it can be seen that, compared to Comparative Examples 1 and 2, Comparative Examples 3 and 4 did not add lanthanum nitrate in the preparation of the tea polyphenol-chitosan modified material, nor did they add 2-chloroethanethiol in the preparation of the dimethylglyoxime-type polyurethane resin. Therefore, according to Table 1, the tensile strength and mechanical properties of the well site cofferdams prepared in Comparative Examples 3 and 4 are significantly reduced. Combined with Example 1, it can be demonstrated that, under the premise of the presence of dimethylglyoxime in the technical solution of this invention, the addition of lanthanum nitrate and 2-chloroethanethiol has a synergistic effect in increasing the corrosion resistance and tensile strength of the well site cofferdam.

[0096] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. An environmentally friendly polyurethane elastomer well site cofferdam, characterized in that: By weight, it includes 60-65 parts of matrix polyurethane resin, 15-18 parts of chain extender, 6-8 parts of plasticizer and 10-15 parts of tea polyphenol-butanedione oxime type polyurethane resin coating. The tea polyphenol-dimethyl oxime type polyurethane resin coating includes mercapto silica-modified plant fibers and lanthanum-modified tea polyphenol-chitosan composite.

2. The environmentally friendly polyurethane elastomer well site cofferdam according to claim 1, characterized in that: The preparation method of the tea polyphenol-butanedione oxime type polyurethane resin coating is as follows: S1: By weight, 14-16 parts of dimethylglyoxime polyurethane resin, 3-5 parts of mercaptosilica-modified plant fiber, 0.1-0.15 parts of benzoin dimethyl ether and 0.2-0.25 parts of p-toluenesulfonic acid are stirred at high speed until uniform, and then irradiated with ultraviolet light while stirring. The mixture is then cooled to 50°C and cured for 1 hour, and then vacuum dried to obtain modified dimethylglyoxime polyurethane resin. S2: By weight, 4-5 parts of tea polyphenol-chitosan modified material and 8-10 parts of modified dimethyl ethyl oxime type polyurethane resin are mixed to obtain tea polyphenol-dimethyl oxime type polyurethane resin coated material.

3. The environmentally friendly polyurethane elastomer well site cofferdam according to claim 2, characterized in that: The preparation method of the tea polyphenol-chitosan modified product is as follows: by weight, add 0.5-1 times the mass of lanthanum chloride to 5 parts of a 10% tea polyphenol solution and mix evenly. Adjust the pH to 6-8, heat and react at room temperature for 1-2 hours, centrifuge, wash, dry, disperse in a chitosan-glacial acetic acid solution, and stir evenly to obtain the tea polyphenol-chitosan modified product.

4. The environmentally friendly polyurethane elastomer well site cofferdam according to claim 2, characterized in that: The preparation method of the dimethylglyoxime type polyurethane resin is as follows: 7-7.5 parts by weight of polytetrahydrofuran diol, 2-2.5 parts of isophorone diisocyanate, 2-2.5 parts of dimethylglyoxime, 0.1-0.3 parts of dibutyltin dilaurate and 0.8-1 parts of hydroxyethyl acrylate are reacted at 80°C for 2 hours. Then, 0.6-0.8 parts of trimethylolpropane and 2-2.5 parts of dimethylglyoxime are added to carry out a crosslinking reaction. After drying, the dimethylglyoxime type polyurethane resin is obtained.

5. The environmentally friendly polyurethane elastomer well site cofferdam according to claim 2, characterized in that: The preparation method of the mercaptosilica-modified plant fiber is as follows: by weight, 1-2 parts of nano-silica are dispersed in water and stirred evenly, 10-12 parts of pretreated plant fiber are added, 2-3 parts of 2-chloroethanethiol are added, the temperature is raised to 65-70℃, the reaction is carried out for 1 hour, cooled, filtered, and dried to obtain mercaptosilica-modified plant fiber.

6. An environmentally friendly polyurethane elastomer well site cofferdam according to any one of claims 1-5, characterized in that: The method for preparing the polyurethane elastomer well site cofferdam is as follows: A1; By weight, 80-85 parts of polyether polyol are dehydrated at 100-110℃, cooled to 40-50℃, 60-80 parts of diisocyanate are added, and reacted at 80-85℃ for 2-2.5h under nitrogen atmosphere to obtain the matrix polyurethane resin. Tea polyphenol-butanedione oxime type polyurethane resin coating is added and stirred at 80-85℃ for 2h. Vacuum degassing is performed, and the material is cooled and discharged to obtain polyurethane elastomer prepolymer. A2: Mix the polyurethane elastomer prepolymer, chain extender and plasticizer evenly, degas, put it into a mold and cold press to form an elastomer well site cofferdam.

7. The environmentally friendly polyurethane elastomer well site cofferdam according to claim 6, characterized in that: The polyether polyol is at least one of polytetrahydrofuran diol, polyethylene glycol, polypropylene glycol, and polyepoxypropylene polyol, with a number average molecular weight of 2000-3000.

8. The environmentally friendly polyurethane elastomer well site cofferdam according to claim 6, characterized in that: The diisocyanate includes one or more of 1,6-hexamethylene diisocyanate, triisocyanate nonane, toluene diisocyanate (TDI), diphenylmethane diisocyanate (MDI), and isophorone diisocyanate.

9. The environmentally friendly polyurethane elastomer well site cofferdam according to claim 6, characterized in that: The chain extender is one or more of di-o-chloroanilinemethane, dimethylthiotoluenediamine, diethyltoluenediamine, 2,4-diamino-3,5-dimethylthiochlorobenzene, and 2,4-diamino-3-methylthio-5-propylchlorobenzene.

10. The environmentally friendly polyurethane elastomer well site cofferdam according to claim 6, characterized in that: The plasticizer is at least one selected from dioctyl adipate, dioctyl sebacate, toluene diphenyl phosphate, diphenyl isodecanyl phosphate, and tributyl acetylcitrate.