Composite material for industrial oil-water separation treatment and preparation method thereof

Abstract

The invention belongs to the technical field of composite material preparation, and particularly relates to a composite material for industrial oil-water separation treatment and a preparation method thereof.The composite material for oil-water separation is prepared by taking styrene and vinyl acetate as monomers and adopting a high internal phase emulsion polymerization mode; the surface of the composite material is subjected to roughening treatment so as to assist in constructing a super-hydrophobic surface and improve the hydrophobic performance of the composite material, in addition, the composite material is hydrolyzed under an alkaline condition after polymerization is finished, so that a part of hydroxyl structures are generated on the surface of the composite material, and the hydroxyl structures enable the surface of the composite material to have hydrophilic micro-regions, so that the hydrophobic property of the composite material is improved. The demulsification function is endowed.

Description

Technical Field

[0001] The invention belongs to the technical field of oil-water separation materials, and in particular relates to a composite material for industrial oil-water separation treatment and a preparation method thereof. Background Art

[0002] At present, there are three main methods for oil removal, namely chemical method, physical method and biological method. However, some methods are inefficient, energy-intensive, and may even introduce new pollutants. There is an urgent need to develop new superhydrophobic materials for oil-water separation.

[0003] Among many solutions, low-cost and efficient adsorption methods can achieve rapid recovery of oil spills with less pollution, and are considered to be the most economical, practical and environmentally friendly treatment methods. Polymer-based porous materials have great application potential as oil adsorption materials in the field of oil-water separation due to their high porosity, low density, interconnected pore structure, and hydrophobic and lipophilic properties. However, the service life and separation efficiency of brittle and low-hydrophobic polymer-based porous materials in practical applications are greatly restricted, which increases the cost of oil-water separation. Superhydrophobic materials can be wetted by oil but not by water, so they have an oil-water separation effect. The wettability of the surface of such materials is mainly determined by the chemical composition and surface microstructure of the material surface. Related prior art in the field CN110724221B discloses a method for preparing a magnetic super-hydrophobic polystyrene-based porous material, which is made of raw material styrene monomer, epoxy-containing olefin monomer, amino-modified ferroferric oxide and cross-linking agent, under the action of initiator, water and emulsifier, at 40-80 ° C for 4-24 hours to obtain a magnetic super-hydrophobic polystyrene-based porous material. The magnetic super-hydrophobic polystyrene-based porous material prepared by the invention has both super-hydrophobicity and magnetic response, and can be used for oil-water separation in the food industry, chemical industry and petroleum industry, and can be automatically separated from oil and water under magnetic drive. Although the prior art can achieve a certain degree of oil-water separation, the hydrophobic properties of existing materials still have a lot of room for improvement. Summary of the invention

[0004] In order to solve the technical problems existing in the above-mentioned background technology, the present invention uses styrene and vinyl acetate as monomers and adopts a high internal phase emulsion polymerization method to prepare a composite material for oil-water separation. By adding a poor solvent during the polymerization process, the surface of the composite material is roughened, thereby assisting in the construction of a super-hydrophobic surface and improving the hydrophobic properties of the composite material. In addition, after the polymerization, the composite material is hydrolyzed under alkaline conditions to generate a partial hydroxyl structure on the surface of the composite material. The presence of the hydroxyl structure makes the surface of the composite material have a hydrophilic micro-region, giving it a demulsification function.

[0005] An object of the present invention is to provide a method for preparing a composite material for industrial oil-water separation treatment, which is characterized by comprising the following steps:

[0006] S1: Prepolymerization of composite materials: divinylbenzene and vinyl acetate are used as polymerization monomers, initiator and Span80 are added, high internal emulsion polymerization is adopted, and prepolymerization is carried out at 76-78° C. for 1-2 hours to obtain a prepolymer.

[0007] S2: Hydrophobic modification: The prepolymer obtained in step S1 is cooled to room temperature, and then a porogen is added to the prepolymer system and placed in a constant temperature shaker for 6-8 hours, and then the system temperature is raised to 70-75°C for secondary polymerization for 6-8 hours.

[0008] S3: Hydrolysis of the composite material: The composite material after the hydrophobic modification in step S2 is hydrolyzed with 3-5% sodium hydroxide solution for 0.5-1 h.

[0009] Furthermore, in step S1, the mass ratio of divinylbenzene to vinyl acetate is 4-6:1.

[0010] Furthermore, in step S1, the initiator is selected from any one of azobisisobutyronitrile and dibenzoyl peroxide.

[0011] Furthermore, the amount of the initiator added in step S1 is 6-8% of the total weight of the polymerization monomers.

[0012] Furthermore, in step S1, the weight ratio of Span80 to the polymerization monomer is 1:5-7.

[0013] Furthermore, in step S1, the prepolymerization temperature is 78° C., and the prepolymerization time is 1 hour.

[0014] Furthermore, in step S2, the porogen is any one of butyl acetate and n-heptane.

[0015] Furthermore, in step S2, the mass ratio of the porogen to the polymerizable monomer is 2-4:1.

[0016] Furthermore, after the secondary polymerization in step S2 is completed, the following steps are also included: drying at 50° C. to constant weight, extracting with ethanol as an extractant for 8 hours, and drying at 50° C. to constant weight.

[0017] Another object of the present invention is to provide a composite material for oil-water separation prepared by the above preparation method.

[0018] The technical solution of the present invention has the following beneficial effects:

[0019] In the preparation process of the composite material, the composite material is first prepolymerized for a period of time, and then a porogen is added to the system. The addition of the porogen can assist in forming pores or depressions on the surface of the composite material, promote the surface of the composite material to be rougher, and then improve the hydrophobicity of the composite material. Compared with the addition mode of mixing the porogen with the polymerized monomer before polymerization, since the prepolymer has a relatively high viscosity, the porogen is difficult to enter the interior of the polymerization system, and most of it stays on the surface of the prepolymer. Therefore, the present invention can use a smaller amount of porogen to achieve a relatively high surface pore effect.

[0020] After the composite material is subjected to hydrophobic modification treatment, the composite material is subjected to hydrolysis treatment. The vinyl acetate added in the system can generate a hydroxyl structure by hydrolysis under alkaline conditions. By controlling the hydrolysis conditions, a certain hydrophilic region can be present on the surface of the composite material while the hydrophobic property is kept basically unchanged, and a certain demulsification function is given to the composite material. When the composite material is applied to an oil-water mixed emulsion, the emulsion droplets are simultaneously affected by the hydrophilic effect of the hydrophilic microregion on the surface of the composite material and the hydrophobic effect of the surface of the composite material matrix, and are rapidly deformed and demulsified, thereby improving the oil-water separation ability of the composite material. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 This is a SEM spectrum of the composite material prepared in Example 2 of the present invention;

[0022] Figure 2 The infrared spectra of the composite material of Example 2 before (top) and after (bottom) hydrolysis. DETAILED DESCRIPTION

[0023] In order to better illustrate the purpose, technical solutions and advantages of the present invention, the present invention will be further described below in conjunction with specific embodiments. The present invention can be implemented in many different forms and should not be construed as being limited to the embodiments set forth herein. On the contrary, these embodiments are provided so that this disclosure will be thorough and complete, and the concept of the present invention will be fully conveyed to those skilled in the art, and the present invention will only be limited by the claims.

[0024] Example 1

[0025] Take 40g of divinylbenzene, 10g of vinyl acetate, and add 10g of surfactant Span 80 and 3g of AIBN. Ultrasonicate for 10 minutes to completely dissolve AIBN. Add 1200g of deionized water to the reaction bottle in batches. After adding 120g of deionized water, shake vigorously until the system is completely emulsified, and finally obtain a viscous high internal phase emulsion. Place the emulsion in a 78℃ oven, prepolymerize for 2 hours, and then cool to room temperature.

[0026] Then, 120 g of butyl acetate was added to the prepolymer system and the system was placed in a constant temperature shaker and shaken at room temperature for 8 h, and then the system temperature was raised to 76°C for secondary polymerization for 8 h. After the polymerization, the system was dried at 50°C to constant weight, extracted with ethanol for 8 h, and dried at 50°C to constant weight.

[0027] The obtained material is then immersed in a 5% sodium hydroxide solution for hydrolysis at 60° C. for 0.5 h, the sodium hydroxide is removed, and the material is dried at 50° C. to a constant weight.

[0028] Example 2

[0029] Take 50g of divinylbenzene, 10g of vinyl acetate, and add 10g of surfactant Span 80 and 3g of AIBN. Ultrasonicate for 10 minutes to completely dissolve AIBN. Add 1200g of deionized water to the reaction bottle in batches. After adding 120g of deionized water, shake vigorously until the system is completely emulsified, and finally obtain a viscous high internal phase emulsion. Place the emulsion in a 78℃ oven, prepolymerize for 1h, and then cool to room temperature.

[0030] Then, 120 g of butyl acetate was added to the prepolymer system and the system was placed in a constant temperature shaker and shaken at room temperature for 6 h, and then the system temperature was raised to 78°C for secondary polymerization for 6 h. After the polymerization, the system was dried at 50°C to constant weight, extracted with ethanol for 8 h, and dried at 50°C to constant weight.

[0031] The obtained material was then immersed in a 4% sodium hydroxide solution for hydrolysis at 60° C. for 1 h, the sodium hydroxide was removed, and the material was dried at 50° C. to constant weight.

[0032] Example 3

[0033] Take 60g of divinylbenzene, 10g of vinyl acetate, and add 10g of surfactant Span 80 and 3g of AIBN. Ultrasonicate for 10 minutes to completely dissolve the AIBN. Add 1200g of deionized water to the reaction bottle in batches. After adding 120g of deionized water, shake vigorously until the system is completely emulsified, and finally obtain a viscous high internal phase emulsion. Place the emulsion in a 78℃ oven, prepolymerize for 1h, and then cool to room temperature.

[0034] Then, 280 g of butyl acetate was added to the prepolymer system and the system was placed in a constant temperature shaker and shaken at room temperature for 7 h, and then the system temperature was raised to 76°C for secondary polymerization for 7 h. After the polymerization, the system was dried at 50°C to constant weight, extracted with ethanol as the extractant for 8 h, and dried at 50°C to constant weight.

[0035] The obtained material was then immersed in a 3% sodium hydroxide solution and hydrolyzed at 60° C. for 1 h, the sodium hydroxide was removed and the material was dried at 50° C. to constant weight.

[0036] Comparative Example 1

[0037] Take 50g of divinylbenzene, 10g of vinyl acetate, and add 10g of surfactant Span 80 and 3g of AIBN. Ultrasonicate for 10 minutes to completely dissolve AIBN. Add 1200g of deionized water to the reaction bottle in batches. After adding 120g of deionized water, shake vigorously until the system is completely emulsified, and finally obtain a viscous high internal phase emulsion. Place the emulsion in a 78℃ oven, prepolymerize for 1h, and then cool to room temperature.

[0038] Then, 120 g of butyl acetate was added to the prepolymer system and the system was placed in a constant temperature shaker and shaken at room temperature for 6 h, and then the system temperature was raised to 78°C for secondary polymerization for 6 h. After the polymerization, the system was dried at 50°C to constant weight, extracted with ethanol for 8 h, and dried at 50°C to constant weight.

[0039] Comparative Example 2

[0040] Take 50g of divinylbenzene, 10g of vinyl acetate, and add 10g of surfactant Span 80 and 3g of AIBN. Ultrasonicate for 10 minutes to completely dissolve AIBN. Add 1200g of deionized water to the reaction bottle in batches. After adding 120g of deionized water, shake vigorously until the system is completely emulsified, and finally obtain a viscous high internal phase emulsion. The emulsion is placed in a 78°C oven for polymerization for 7h. After the polymerization is completed, dry to constant weight at 50°C, use ethanol as the extractant, extract for 8h, and dry to constant weight at 50°C. Then immerse the obtained material in a 4% sodium hydroxide solution and hydrolyze it at 60°C for 1h, remove the sodium hydroxide and dry to constant weight at 50°C.

[0041] Comparative Example 3

[0042] Take 50g of divinylbenzene, 10g of vinyl acetate, add 10g of surfactant Span 80, 3g of AIBN, 120g of butyl acetate, and ultrasonicate for 10min to completely dissolve AIBN. Add 1200g of deionized water to the reaction bottle in batches. After adding 120g of deionized water, shake vigorously until the system is completely emulsified, and finally obtain a viscous high internal phase emulsion. The emulsion is placed in a 78℃ oven for polymerization for 7h. After the polymerization is completed, dry to constant weight at 50℃, use ethanol as the extractant, extract for 8h, and dry to constant weight at 50℃.

[0043] The obtained material was then immersed in a 4% sodium hydroxide solution for hydrolysis at 60° C. for 1 h, the sodium hydroxide was removed, and the material was dried at 50° C. to constant weight.

[0044] Embodiment and comparative example composite material structure characterization:

[0045] The microstructure of the material was observed by field emission scanning electron microscopy; the infrared spectrum (FTIR) of the sample was measured by Thermo Fisher Nicolet460 spectrometer; the results are shown in Figure 1 and Figure 2 shown.

[0046] Performance test of the composite materials described in the embodiments and comparative examples:

[0047] Oil absorption rate test: Take the cut and dried sample and weigh it, put the sample in the oil to be tested (including chloroform, petroleum ether, ethanol, toluene, diesel), soak it until adsorption saturation, absorb it with filter paper and weigh it, and calculate the oil absorption rate of the composite material; the results are shown in Table 1;

[0048] Oil retention rate test: The oil-saturated sample was centrifuged at 3000 r / min for 10 min to remove the oil in the sample, and the residual sample mass was weighed. The oil retention rate was calculated based on the mass difference. The results are shown in Table 2.

[0049] The water contact angle and oil contact angle of the composite materials prepared in the examples and comparative examples were measured using a contact angle meter of model JC2000C. The liquids used were deionized water and soybean oil, respectively. The test results are shown in Table 1.

[0050] Table 1 Oil absorption and contact angle of composite materials prepared in Examples and Comparative Examples

[0051]

[0052]

[0053] Table 2 Oil retention rate of composite materials prepared in Examples and Comparative Examples

[0054] project Chloroform(%) Petroleum ether (%) Toluene(%) gasoline(%) Example 1 96.1 97.2 96.2 96.8 Example 2 96.9 97.8 96.9 97.1 Example 3 96.3 97.5 96.1 96.6 Comparative Example 1 85.3 92.6 91.5 92.4 Comparative Example 2 89.6 94.3 93.1 93.5 Comparative Example 3 95.1 95.6 94.8 94.6

[0055] By comparing and analyzing the relevant data in Table 1 and Table 2, it can be seen that in the preparation process of the composite material, the composite material is first pre-polymerized for a period of time, and then a porogen is added to the system. The addition of the porogen can assist in pore formation or depression on the surface of the composite material, promote the surface of the composite material to be rougher, and then improve the hydrophobicity of the composite material. Compared with the addition mode of mixing the porogen with the polymerized monomer before polymerization, since the prepolymer has a relatively high viscosity, the porogen is difficult to enter the interior of the polymerization system, and most of it stays on the surface of the prepolymer. Therefore, the present invention can use less porogen to achieve a relatively high surface pore effect.

[0056] After the composite material is subjected to hydrophobic modification treatment, the composite material is subjected to hydrolysis treatment. The vinyl acetate added in the system can generate a hydroxyl structure by hydrolysis under alkaline conditions. By controlling the hydrolysis conditions, a certain hydrophilic region can be present on the surface of the composite material while the hydrophobic property is kept basically unchanged, and a certain demulsification function is given to the composite material. When the composite material is applied to an oil-water mixed emulsion, the emulsion droplets are simultaneously affected by the hydrophilic effect of the hydrophilic microregion on the surface of the composite material and the hydrophobic effect of the surface of the composite material matrix, and are rapidly deformed and demulsified, thereby improving the oil-water separation ability of the composite material.

[0057] It should be noted that the embodiments described above are only used to explain the present invention and do not constitute any limitation to the present invention. The present invention has been described with reference to typical embodiments, but it should be understood that the words used therein are descriptive and explanatory words, rather than restrictive words. The present invention may be modified as specified within the scope of the claims of the present invention, and the present invention may be revised without departing from the scope and spirit of the present invention. Although the present invention described therein relates to specific methods, materials and embodiments, it does not mean that the present invention is limited to the specific examples disclosed therein, on the contrary, the present invention can be extended to all other methods and applications with the same functions.

Claims

1. A method for preparing a composite material for industrial oil-water separation treatment, characterized in that The steps include: S1: Prepolymerization of composite materials: using divinylbenzene and vinyl acetate as polymerization monomers, adding initiator and Span 80, adopting high internal emulsion polymerization, prepolymerizing at 76-78°C for 1-2h to obtain a prepolymer; S2: Hydrophobic modification: The prepolymer obtained in step S1 is cooled to room temperature, and then a porogen is added to the prepolymer system and placed in a constant temperature shaker for 6-8 hours, and then the system temperature is raised to 70-75°C for secondary polymerization for 6-8 hours; S3: Hydrolysis of the composite material: The composite material after the hydrophobic modification in step S2 is hydrolyzed with 3-5% sodium hydroxide solution for 0.5-1 h.

2. The method for preparing a composite material for industrial oil-water separation treatment according to claim 1, characterized in that: In step S1, the mass ratio of divinylbenzene to vinyl acetate is 4-6:

1.

3. The method for preparing a composite material for industrial oil-water separation treatment according to claim 1, characterized in that: In step S1, the initiator is selected from any one of azobisisobutyronitrile and dibenzoyl peroxide.

4. The method for preparing a composite material for industrial oil-water separation treatment according to claim 1, characterized in that: The amount of the initiator added in step S1 is 6-8% of the total weight of the polymerization monomers.

5. The method for preparing a composite material for industrial oil-water separation treatment according to claim 1, characterized in that: In step S1, the weight ratio of Span80 to the polymerization monomer is 1:5-7.

6. The method for preparing a composite material for industrial oil-water separation treatment according to claim 1, characterized in that: The prepolymerization temperature in step S1 is 78° C. and the prepolymerization time is 1 hour.

7. The method for preparing a composite material for industrial oil-water separation treatment according to claim 1, characterized in that: The porogen in step S2 is any one of butyl acetate and n-heptane. The mass ratio of the porogen to the polymerizable monomer in step S2 is 2-4:

1.

8. The method for preparing a composite material for industrial oil-water separation treatment according to claim 1, characterized in that: After the secondary polymerization in step S2 is completed, the following steps are further included: drying at 50° C. to constant weight, extracting with ethanol as an extractant for 8 hours, and drying at 50° C. to constant weight.

9. The method for preparing a composite material for industrial oil-water separation treatment according to claim 1, characterized in that: In step S2, the mass ratio of the porogen to the polymerizable monomer is 2-4:

1.

10. A composite material for industrial oil-water separation treatment, characterized in that The compound is prepared by the preparation method described in any one of claims 1 to 9.

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