A long-acting super-hydrophobic polyurethane sponge, a sponge preparation method and a water surface oil stain removal method

Abstract

The application belongs to the technical field of oil-water separation, and particularly relates to a long-acting super-hydrophobic polyurethane sponge, a sponge preparation method and a water surface oil stain removal method. After hydrophobic treatment of nano-ZnO and micro-SiO2 by using a silane compound, in-situ polymerization and foaming are performed together with a polyurethane prepolymer to obtain the super-hydrophobic polyurethane sponge. The hydrophobically modified nano-ZnO and the hydrophobically modified micro-SiO2 reduce the surface energy, so that the polyurethane sponge has super-hydrophobic performance and excellent oil-water separation performance. The silane compound on the surface of the hydrophobically modified nano-ZnO and the hydrophobically modified micro-SiO2 has strong interaction with the polyurethane molecules, the in-situ polymerization and foaming process uniformly distributes the micro-nano composite structure composed of the hydrophobically modified nano-ZnO and the hydrophobically modified micro-SiO2 on the surface and inside of the sponge, improves the mesoscopic roughness of the polyurethane sponge, thereby prolongs the service life of the sponge hydrophobic function, and has a significant advantage in water surface oil removal.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of oil-water separation, and particularly relates to a long-acting super-hydrophobic polyurethane sponge, a preparation method of the sponge, and a method for removing oil stains on a water surface. BACKGROUND

[0002] With the rapid development of modern industry, marine oil transportation and other industries are also developing rapidly, but oil leakage and organic matter leakage accidents occur frequently, causing great damage to the environment and serious impact on the ecological and environmental system.

[0003] The commonly used methods for removing oil pollutants in water include adsorption treatment, chemical dispersion and sedimentation treatment, and microbial degradation. These methods have their own limitations, such as long treatment time, high production cost, low separation efficiency, and easy secondary pollution. In contrast, material adsorption method is widely used in oil pollution treatment due to its own rapid and efficient adsorption performance, recyclability, and no secondary pollution. The principle of material adsorption method is to adsorb and store oil in the pores of the material through capillary action, and the adsorbed oil in the pores can be recovered through external force such as centrifugation and extrusion. However, traditional adsorption materials have poor oil-water selectivity, and water is also adsorbed during the oil adsorption process. The oil adsorption rate of high-viscosity oil is slow and the efficiency is low, and effective oil-water separation cannot be achieved, which restricts the application of adsorption materials in oil spill emergencies.

[0004] Polyurethane sponge not only has good stability, resilience, chemical resistance and mechanical properties, but also has high porosity, large specific surface area and interconnected pore structure when used as an adsorbent. However, ordinary polyurethane sponge lacks selective oil-water absorption function and cannot achieve efficient oil-water separation. To achieve efficient oil-water separation of polyurethane sponge, the surface of polyurethane sponge must be modified. The commonly used methods for modifying the surface of polyurethane sponge are as follows: first, constructing a micro-nano composite structure on the surface of polyurethane sponge to increase the mesoscopic roughness of the material, thereby increasing the contact angle and hydrophobicity of the material, so that the polyurethane sponge has efficient oil-water separation performance; second, coating a low-surface-energy material on the surface of the polyurethane sponge to make the surface of the polyurethane sponge super-hydrophobic and oleophilic. However, the surface micro-nano composite structure will be damaged and the low-surface-energy material on the surface of the polyurethane sponge will fall off after long-term use, affecting the stability and hydrophobicity of the sponge and greatly reducing the oil absorption efficiency and the effect of repeated use.

[0005] In summary, it is of great practical significance to develop an economical, long-term recyclable, and fast and efficient adsorbent for removing oil stains in water, but it also faces many challenges. SUMMARY

[0006] In order to overcome the deficiencies of the prior art, the first aspect of the present application provides a long-acting super-hydrophobic polyurethane sponge and a preparation method thereof. A silane compound is used to treat nano-ZnO and micro-SiO2 to reduce the surface energy of the nano-ZnO and the micro-SiO2 and improve the hydrophobicity; the hydrophobically modified nano-ZnO and the hydrophobically modified micro-SiO2 are added to a polyurethane prepolymer, uniformly mixed, and then subjected to in-situ polymerization to obtain a super-hydrophobic polyurethane; and the super-hydrophobic polyurethane is subjected to free foaming in a mold to obtain the long-acting super-hydrophobic polyurethane sponge. On the one hand, the silane compound is used for modification treatment to reduce the surface energy of the powder, and on the other hand, the nano-ZnO and the micro-SiO2 are uniformly distributed in the polyurethane sponge obtained by in-situ polymerization and foaming, so that a micro-nano composite structure is formed on the surface and inside of the sponge, the mesoscopic roughness of the polyurethane sponge is improved, and the problem that the micro-nano composite structure is easily damaged is solved. The long-acting super-hydrophobic polyurethane sponge has low price, excellent oil absorption performance, and stable performance, and can solve the problems of low separation efficiency and poor repeatability of the polyurethane sponge for oil-water separation at the present stage.

[0007] The preparation method of the long-acting super-hydrophobic polyurethane sponge of the present application comprises the following steps:

[0008] Step 1: 50-80 parts by mass of polyhydric alcohol, 2-3 parts by mass of water, 1-4 parts by mass of foaming agent, 0.5-1.5 parts by mass of catalyst, and 0.4-1 part by mass of foam stabilizer are uniformly mixed at a temperature of 15-30 DEG C to obtain polyurethane auxiliary materials, i.e. component A;

[0009] Step 2: 50-75 parts by mass of polyisocyanate are added to a reaction container, stirred at a temperature of 60-80 DEG C for 20-40 min, then polyhydric alcohol is added at a mass ratio of polyisocyanate to polyhydric alcohol of 100:40-100:75, and the polyurethane prepolymer, i.e. component B, is obtained by reaction at a temperature of 60-80 DEG C;

[0010] Step 3: 5-20 parts by mass of nano-ZnO is dispersed in 60-80 parts by mass of solvent, then 1-3 parts by mass of silane compound is added dropwise, and the mixture is reacted at a temperature of 60-80 DEG C for 3-6 h, then the solid is separated, washed and dried to obtain hydrophobically modified ZnO powder, i.e. component C;

[0011] Step 4: 5-20 parts by mass of micro-SiO2 is dispersed in 60-80 parts by mass of solvent, then 1-3 parts by mass of silane compound is added dropwise, and the mixture is reacted at a temperature of 60-80 DEG C for 3-6 h, then the solid is separated, washed and dried to obtain hydrophobically modified SiO2 powder, i.e. component D;

[0012] Step 5: Component A, component B, component C, and component D are mixed in a mass ratio of component A: component B: component C: component D of 45-55:100:5-20:5-20, and an in-situ polymerization reaction is performed to prepare a super hydrophobic polyurethane;

[0013] Step 6: Pour the super-hydrophobic polyurethane obtained in the above step 5 into a mold to carry out a free foaming reaction, and after drying, obtain a long-lasting super-hydrophobic polyurethane sponge.

[0014] Preferably, in step 3, 5 to 20 parts by mass of nano-ZnO are added to 60 to 80 parts by mass of 80% ethanol aqueous solution, and then acetic acid is added dropwise until the pH value of the solution is 4. After mixing, 1 to 3 parts by mass of a silane compound are added dropwise under stirring conditions, and the reaction is carried out at a temperature of 60 to 80° C. for 3 to 6 hours. The solid is then separated by centrifugation, washed with distilled water, and filtered, and the washing and filtration steps are repeated 1 to 4 times. The filtered solid is vacuum dried at 60° C. to constant weight, crushed, and sieved to obtain a hydrophobically modified ZnO powder, i.e., component C.

[0015] Preferably, in step 4, 5 to 20 parts by mass of nano-SiO2 are added to 60 to 80 parts by mass of 80% ethanol aqueous solution, and then acetic acid is added dropwise until the pH value of the solution is 4. After mixing, 1 to 3 parts by mass of silane compound are added dropwise under stirring conditions, and the reaction is carried out at a temperature of 60 to 80°C for 3 to 6 hours. The solid is then separated by centrifugation, washed with distilled water and filtered, and the washing and filtration steps are repeated 1 to 4 times. The filtered solid is vacuum dried at 60°C to constant weight, crushed and sieved to obtain hydrophobically modified SiO2 powder, i.e., component D.

[0016] Preferably, in step 5, according to the mass ratio of component A: component B: component C: component D of 50:100:5-20:5-20, component A, component B, component C and component D are respectively weighed and placed in a reaction vessel, and the super hydrophobic polyurethane is obtained after in-situ polymerization for 10-30 minutes at a temperature of 20-40 ° C and a rotation speed of 200-300 r / min.

[0017] Preferably, in step 6, the super-hydrophobic polyurethane obtained in step 5 is poured into a mold, stirred at a temperature of 20 to 40 ° C and a rotation speed of 1000 to 1500 r / min for 15 to 30 s, then poured into a mold, and subjected to free foaming reaction at 20 to 40 ° C for 3 to 5 minutes, and then the foamed polyurethane sponge is taken out and placed in a 60 to 80 ° C oven with a flow rate of 50 ml / min flowing N2 and dried for 3 to 6 hours to obtain the long-lasting super-hydrophobic polyurethane sponge.

[0018] Preferably, the polyol in step 1 and step 2 is one or more of polytetrahydrofuran diol, polycarbonate diol, polycaprolactone diol, polypropylene glycol.

[0019] Preferably, the blowing agent in step 1 is one or more of dichloromethane, 1,1,1,3,3-pentafluorobutane, 1,1,1,3,3-pentafluoropropane, 1,1,1,2-tetrafluoroethane, difluoroethane, heptafluoropropane.

[0020] Preferably, the catalyst in step 1 is selected from organometallic catalyst, tertiary amine catalyst, preferably organometallic catalyst, wherein the organometallic catalyst is one or more of dibutyltin dilaurate, stannous octoate, dibutyltin acetate.

[0021] Preferably, the foam stabilizer in step 1 is one or more of dimethyl silicone oil, dodecyl dimethyl amine oxide, alkyl alcohol amide.

[0022] Preferably, the polyisocyanate in step 2 is one or more of isophorone diisocyanate, hexamethylene diisocyanate, toluene diisocyanate.

[0023] Preferably, the silane compound in step 3 is one or more of 3-aminopropyl triethoxysilane, 3-aminopropyl trimethoxysilane, N-β(aminoethyl)-γ-aminopropyl trimethoxysilane, N-β(aminoethyl)-γ-aminopropyl methyl dimethoxysilane, N-β(aminoethyl)-γ-aminopropyl triethoxysilane.

[0024] Preferably, the nano-ZnO particle size in step 3 is 50-300 nm, further preferably 100-200 nm.

[0025] Preferably, the micron-SiO2 particle size in step 4 is 50-300 μm, further preferably 50-100 μm.

[0026] The long-acting super-hydrophobic polyurethane sponge can be prepared by the above method, the water contact angle of which can reach 150-165°, the adsorption amount of petroleum ether, kerosene, etc. can reach 50-60 times of its own weight, and after 100 adsorption-desorption cycles, the adsorption effect on oil can still maintain more than 95% of the first oil absorption rate, and the separation efficiency of oil / water mixture is more than 99%. It can be used for rapid adsorption of oil and various organic solvents in water to achieve efficient water-oil separation. Due to the simple preparation method, strong operability, and recyclable characteristics of the oil-absorbing sponge, it is expected to be widely used for water oil pollution removal to greatly improve the ecological environment.

[0027] The second aspect of the present application is a method for removing oil stains on water surface based on the long-acting super-hydrophobic polyurethane sponge. Specifically, the long-acting super-hydrophobic polyurethane sponge is put into the water area with oil stains, the oil stains on the water surface are adsorbed by the long-acting super-hydrophobic polyurethane sponge, and then the long-acting super-hydrophobic polyurethane sponge is collected, the oil stains are separated by centrifugation or extrusion, and the regenerated sponge after separating the oil stains is put into the next round of use. The method for removing oil stains on water surface utilizes the high-efficiency adsorption of oil pollutants by the long-acting super-hydrophobic polyurethane sponge, realizes the rapid separation of oil and water, and the sponge can be recycled, which helps to continuously improve the water quality and ecological environment.

[0028] Compared with the prior art, the present application has the following beneficial effects:

[0029] (1) In the present application, the hydrophobically modified nano-ZnO and the hydrophobically modified micro-SiO2 are added into the polyurethane prepolymer to prepare the super-hydrophobic polyurethane sponge. The surface energy of the nano-ZnO and the micro-SiO2 is reduced by the hydrophobic modification, and the hydrophobicity is improved, so that the polyurethane sponge has super-hydrophobic performance, the oil-water separation capacity is improved, and excellent oil-water separation performance is achieved. The water contact angle of the prepared hydrophobic polyurethane foam is in the range of 150°-165°, and the adsorption amount of petroleum ether, kerosene and the like can reach 50-60 times of its own weight.

[0030] (2) In the present application, after the nano-ZnO and the hydrophobically modified micro-SiO2 are hydrophobically modified, on the one hand, the silane compound introduced on the surface enhances the interaction with the polyurethane molecules, and on the other hand, it is in-situ polymerized with the polyurethane prepolymer and free-foamed, and the micro-nano composite structure is uniformly distributed on the surface and inside of the sponge, improving the mesoscopic roughness of the polyurethane sponge. As a result, the service life of the hydrophobic function of the sponge is prolonged. After 100 adsorption-desorption cycles, the adsorption effect on oil can still maintain more than 95% of the first oil absorption rate, and the separation efficiency of oil / water mixture is more than 99%.

[0031] (3) The present application relates to a preparation method of a long-acting super-hydrophobic polyurethane sponge applied to oil-water separation, which only needs to use conventional production equipment, does not need special equipment investment, has simple process control, low production cost, and can be conveniently mass-produced.

[0032] (4) The present application also proposes a method for removing oil stains on water surface, which utilizes the excellent oil absorption capacity, oil-water separation efficiency and durability of the long-acting super-hydrophobic polyurethane sponge, realizes the rapid separation of oil and water, and the sponge can be recycled for a long time, which helps to continuously improve the water quality and ecological environment. DETAILED DESCRIPTION

[0033] The present application will be further illustrated by specific examples, which are exemplary and intended to illustrate the problems and explain the present application, but are not a limitation.

[0034] Example 1

[0035] Step 1: In a three-necked flask, add polytetrahydrofuran diol 25 g, water 1 g, dichloromethane 1 g, dibutyl tin dilaurate 0.4 g, dimethyl silicone oil 0.5 g, stir for 15 min under the condition of temperature 25 °C and stirring speed 200 r / min, to prepare the auxiliary material, i.e. component A;

[0036] Step 2: In a three-necked flask, add isophorone diisocyanate 50 g, stir for 30 min under the condition of temperature 60 °C and stirring speed 200 r / min, then add polytetrahydrofuran diol 25 g, react for 3 h under the condition of temperature 70 °C and stirring speed 200 r / min, to prepare the prepolymer, i.e. component B;

[0037] Step 3: In a three-necked flask, add 5 g nano-ZnO and 60 g 80% ethanol aqueous solution, then add acetic acid dropwise until the pH value of the solution is 4. Ultrasonic treatment for 30 min, then add 1 g 3-aminopropyl triethoxysilane dropwise under the condition of stirring speed 250 r / min, and condense reflux under the condition of temperature 60 °C and stirring speed 250 r / min, react for 4 h, then pour into a centrifuge tube and centrifuge at 10000 r / min for 20 min, to obtain hydrophobic modified ZnO. Wash the modified ZnO with distilled water, suction filter for 3 times, and vacuum dry at 70 °C for 24 h to constant weight, crush and pass through a 12500 mesh sieve to obtain hydrophobic modified ZnO powder, i.e. component C;

[0038] Step 4: In a three-necked flask, add 5 g micron-SiO2 and 60 g 80% ethanol aqueous solution, then add acetic acid dropwise until the pH value of the solution is 4. Ultrasonic treatment for 30 min, then add 1 g 3-aminopropyl triethoxysilane dropwise under the condition of stirring speed 250 r / min, and condense reflux under the condition of temperature 60 °C and stirring speed 250 r / min, react for 4 h, then pour into a centrifuge tube and centrifuge at 10000 r / min for 20 min, to obtain hydrophobic modified SiO2. Wash the modified SiO2 with distilled water, suction filter for 3 times, and vacuum dry at 60 °C for 24 h to constant weight, crush and pass through a 250 mesh sieve to obtain hydrophobic modified SiO2 powder, i.e. component D;

[0039] Step 5: According to the mass ratio of component A: component B: component C: component D being 50: 100: 5: 5, and the total mass being 50 g, weigh component A, component B, component C and component D respectively, and put them into a flask in turn, to carry out in-situ polymerization under the condition of temperature 20 °C and rotation speed 300 r / min for 30 min, then stir under the condition of temperature 25 °C and rotation speed 1200 r / min for 30 s, to prepare super-hydrophobic polyurethane;

[0040] Step 6: The super-hydrophobic polyurethane obtained in step 5 was poured into a mold, and a free foaming reaction was carried out at 20℃ for 5 min, then the foamed polyurethane sponge was taken out and placed in an oven at 60℃ with a flow rate of 50 ml / min flowing N2for 4 h, to obtain the super-hydrophobic polyurethane sponge.

[0041] Example 2

[0042] Step 1: A three-necked flask was charged with polytetrahydrofuran glycol 25 g, water 1 g, dichloromethane 1 g, dibutyl tin dilaurate 0.4 g, and dimethyl silicone oil 0.5 g, and stirred at a temperature of 25℃ and a stirring speed of 200 r / min for 15 min to prepare the auxiliary, i.e. component A;

[0043] Step 2: A three-necked flask was charged with isophorone diisocyanate 50 g, and stirred at a temperature of 60℃ and a stirring speed of 200 r / min for 30 min, then polytetrahydrofuran glycol 25 g was added, and reacted at a temperature of 70℃ and a stirring speed of 200 r / min for 3 h to prepare the prepolymer, i.e. component B;

[0044] Step 3: A three-necked flask was charged with 5 g of nano-ZnO and 60 g of 80% aqueous ethanol solution, then acetic acid was added dropwise until the pH value of the solution was 4. Ultrasonic treatment was carried out for 30 min, then 1 g of N-β(aminoethyl)-γ-aminopropyl dimethoxysilane was added dropwise under stirring at a speed of 250 r / min, and condensed reflux was carried out at a temperature of 60℃ and a stirring speed of 250 r / min. After reacting for 4 h, it was poured into a centrifuge tube and centrifuged at a speed of 10000 r / min for 20 min to obtain hydrophobically modified ZnO. The modified ZnO was washed with distilled water, suction filtered 3 times, and vacuum dried at 70℃ for 24 h to a constant weight, then crushed and sieved through a 12500 mesh sieve to obtain hydrophobically modified ZnO powder, i.e. component C;

[0045] Step 4: A three-necked flask was charged with 5 g of micron-sized SiO2 and 60 g of 80% aqueous ethanol solution, then acetic acid was added dropwise until the pH value of the solution was 4. Ultrasonic treatment was carried out for 30 min, then 1 g of N-β(aminoethyl)-γ-aminopropyl dimethoxysilane was added dropwise under stirring at a speed of 250 r / min, and condensed reflux was carried out at a temperature of 60℃ and a stirring speed of 250 r / min. After reacting for 4 h, it was poured into a centrifuge tube and centrifuged at a speed of 10000 r / min for 20 min to obtain hydrophobically modified SiO2. The modified SiO2 was washed with distilled water, suction filtered 3 times, and vacuum dried at 60℃ for 24 h to a constant weight, then crushed and sieved through a 250 mesh sieve to obtain hydrophobically modified SiO2 powder, i.e. component D;

[0046] Step 5: according to the mass ratio of component A: component B: component C: component D is 50: 100: 5: 5, the total mass is 50g, respectively, component A, component B, component C, component D are weighed and put into the flask in turn, under the condition of temperature 20℃, rotation speed 300r / min, in-situ polymerization is carried out for 30min, then under the condition of temperature 25℃, rotation speed 1200r / min, stirring for 30s, the super-hydrophobic polyurethane is prepared;

[0047] Step 6: the super-hydrophobic polyurethane obtained in step 5 is poured into the mold, and the free foaming reaction is carried out at 20℃ for 5min, then the foamed polyurethane sponge is taken out and placed in a 60℃ oven with a flow rate of 50ml / min flowing N2 for 4h, and the super-hydrophobic polyurethane sponge is obtained.

[0048] Example 3

[0049] Step 1: in a three-necked flask, add polytetrahydrofuran glycol 25g, water 1g, dichloromethane 1g, dibutyl tin dilaurate 0.4g, dimethyl silicone oil 0.5g, under the condition of temperature 25℃, stirring speed 200r / min, stirring for 15min, and the auxiliary material, component A, is prepared;

[0050] Step 2: in a three-necked flask, add isophorone diisocyanate 50g, under the condition of temperature 60℃, stirring speed 200r / min, stirring for 30min, then add polytetrahydrofuran glycol 25g, under the condition of temperature 70℃, stirring speed 200r / min, react for 3h, and the prepolymer, component B, is prepared;

[0051] Step 3: in a three-necked flask, add 5g nano-ZnO, 60g 80% ethanol aqueous solution, then add acetic acid dropwise until the pH value of the solution is 4. Ultrasonic treatment for 30min, then add 1g N-β(aminoethyl)-γ-aminopropyl trimethoxysilane dropwise under the condition of stirring speed 250r / min, and condense reflux under the condition of temperature 60℃, stirring speed 250r / min, react for 4h, then pour into a centrifuge tube, centrifuge at 10000r / min for 20min, and the hydrophobic modified ZnO is obtained. The modified ZnO is washed with distilled water, suction filtered 3 times, and vacuum dried at 70℃ for 24h to constant weight, crushed and passed through a 12500 mesh sieve to obtain hydrophobic modified ZnO powder, component C;

[0052] Step 4: 5 g of micron SiO2, 60 g of 80% ethanol aqueous solution were added into a three-necked flask, then acetic acid was added dropwise until the pH value of the solution was 4. After ultrasonic treatment for 30 min, 1 g of N-β(aminoethyl)-γ-aminopropyl trimethoxysilane was added dropwise under the condition of stirring speed of 250 r / min and condensation reflux under the condition of temperature of 60 ℃ and stirring speed of 250 r / min. After reaction for 4 h, it was poured into a centrifuge tube and centrifuged at a speed of 10,000 r / min for 20 min to obtain hydrophobically modified SiO2. The modified SiO2 was washed with distilled water, suction filtered for 3 times, and vacuum dried at 60 ℃ for 24 h to a constant weight, crushed and passed through a 250 mesh sieve to obtain hydrophobically modified SiO2 powder, which was component D;

[0053] Step 5: 50 g of component A, component B, component C and component D were weighed according to the mass ratio of component A: component B: component C: component D of 50: 100: 5: 5, and sequentially put into a flask under the condition of temperature of 20 ℃ and stirring speed of 300 r / min for in-situ polymerization for 30 min, and then stirred at a temperature of 25 ℃ and a stirring speed of 1200 r / min for 30 s to prepare super-hydrophobic polyurethane;

[0054] Step 6: The super-hydrophobic polyurethane obtained in step 5 was poured into a mold and subjected to free foaming reaction at 20 ℃ for 5 min, and then the foamed polyurethane sponge was taken out and placed in a 60 ℃ oven with a flow rate of 50 ml / min of flowing N2 for 4 h to obtain super-hydrophobic polyurethane sponge.

[0055] Example 4

[0056] Step 1: A three-necked flask was added with polytetrahydrofuran diol 25 g, water 1 g, dichloromethane 1 g, dibutyltin dilaurate 0.4 g and dimethyl silicone oil 0.5 g, and stirred at a temperature of 25 ℃ and a stirring speed of 200 r / min for 15 min to prepare an auxiliary material, which was component A;

[0057] Step 2: Isophorone diisocyanate 50 g was added into a three-necked flask, and stirred at a temperature of 60 ℃ and a stirring speed of 200 r / min for 30 min, then polytetrahydrofuran diol 25 g was added, and reacted at a temperature of 70 ℃ and a stirring speed of 200 r / min for 3 h to prepare a prepolymer, which was component B;

[0058] Step 3: 5 g of nano-ZnO was added into 60 g of 80% aqueous ethanol solution in a three-necked flask, and then acetic acid was added dropwise until the pH value of the solution was 4. After ultrasonic treatment for 30 min, 1 g of N-β(aminoethyl)-γ-aminopropyl triethoxysilane was added dropwise under the condition of a stirring speed of 250 r / min, and then condensation reflux was carried out under the condition of a temperature of 60°C and a stirring speed of 250 r / min. After reaction for 4 h, the product was poured into a centrifuge tube and centrifuged at a speed of 10,000 r / min for 20 min to obtain hydrophobically modified ZnO. The modified ZnO was washed with distilled water and suction filtered for 3 times, and then vacuum dried at 70°C for 24 h to a constant weight. After crushing and sieving through a 12500-mesh screen, a hydrophobically modified ZnO powder, i.e., component C, was obtained.

[0059] Step 4: 5 g of micron-SiO2 was added into 60 g of 80% aqueous ethanol solution in a three-necked flask, and then acetic acid was added dropwise until the pH value of the solution was 4. After ultrasonic treatment for 30 min, 1 g of N-β(aminoethyl)-γ-aminopropyl triethoxysilane was added dropwise under the condition of a stirring speed of 250 r / min, and then condensation reflux was carried out under the condition of a temperature of 60°C and a stirring speed of 250 r / min. After reaction for 4 h, the product was poured into a centrifuge tube and centrifuged at a speed of 10,000 r / min for 20 min to obtain hydrophobically modified SiO2. The modified SiO2 was washed with distilled water and suction filtered for 3 times, and then vacuum dried at 60°C for 24 h to a constant weight. After crushing and sieving through a 250-mesh screen, a hydrophobically modified SiO2 powder, i.e., component D, was obtained.

[0060] Step 5: Components A, B, C and D were weighed according to a mass ratio of 50:100:5:5, and the total mass was 50 g. The components were sequentially put into a flask and subjected to in-situ polymerization at a temperature of 20°C and a speed of 300 r / min for 30 min, and then stirred at a temperature of 25°C and a speed of 1200 r / min for 30 s to prepare a super-hydrophobic polyurethane.

[0061] Step 6: The super-hydrophobic polyurethane obtained in step 5 was poured into a mold and subjected to a free foaming reaction at 20°C for 5 min. Then, the foamed polyurethane sponge was taken out and placed in a 60°C oven with a flow rate of 50 ml / min of flowing N2 for 4 h to obtain a super-hydrophobic polyurethane sponge.

[0062] Example 5

[0063] Step 1: A three-necked flask was charged with 25 g of polytetrahydrofuran diol, 1 g of water, 1 g of dichloromethane, 0.4 g of dibutyl tin dilaurate and 0.5 g of dimethyl silicone oil. The mixture was stirred at a temperature of 25°C and a stirring speed of 200 r / min for 15 min to prepare an auxiliary material, i.e., component A.

[0064] Step 2: In a three-necked flask, isophorone diisocyanate 50 g was added, stirred at 60 ℃ and 200 r / min for 30 min, then polytetrahydrofuran diol 25 g was added, reacted at 70 ℃ and 200 r / min for 3 h to prepare a prepolymer, i.e. component B;

[0065] Step 3: In a three-necked flask, 5 g of nano-ZnO was added into 60 g of 80% ethanol aqueous solution, then acetic acid was added dropwise until the pH value of the solution was 4. After ultrasonic treatment for 30 min, 1 g of N-β(aminoethyl)-γ-aminopropyl triethoxysilane was added dropwise under stirring at 250 r / min, and condensed reflux was carried out at 60 ℃ and 250 r / min. After reaction for 4 h, the product was poured into a centrifuge tube and centrifuged at 10,000 r / min for 20 min to obtain hydrophobically modified ZnO. The modified ZnO was washed with distilled water, suction filtered for 3 times, and vacuum dried at 70 ℃ for 24 h to a constant weight. After crushing and passing through a 12500-mesh sieve, hydrophobically modified ZnO powder, i.e. component C, was obtained;

[0066] Step 4: In a three-necked flask, 5 g of micron-SiO2 was added into 60 g of 80% ethanol aqueous solution, then acetic acid was added dropwise until the pH value of the solution was 4. After ultrasonic treatment for 30 min, 1 g of N-β(aminoethyl)-γ-aminopropyl triethoxysilane was added dropwise under stirring at 250 r / min, and condensed reflux was carried out at 60 ℃ and 250 r / min. After reaction for 4 h, the product was poured into a centrifuge tube and centrifuged at 10,000 r / min for 20 min to obtain hydrophobically modified SiO2. The modified SiO2 was washed with distilled water, suction filtered for 3 times, and vacuum dried at 60 ℃ for 24 h to a constant weight. After crushing and passing through a 250-mesh sieve, hydrophobically modified SiO2 powder, i.e. component D, was obtained;

[0067] Step 5: Components A, B, C and D were weighed according to the mass ratio of component A: component B: component C: component D = 50: 100: 10: 10, and the total mass was 50 g. The components were sequentially placed in a flask and subjected to in-situ polymerization at 20 ℃ and 300 r / min for 30 min, and then stirred at 25 ℃ and 1200 r / min for 30 s to prepare a super-hydrophobic polyurethane;

[0068] Step 6: The super-hydrophobic polyurethane obtained in step 5 was poured into a mold and subjected to free foaming reaction at 20 ℃ for 5 min. Then the foamed polyurethane sponge was taken out and placed in a 60 ℃ oven with a flow rate of 50 ml / min of flowing N2 for 4 h to obtain a super-hydrophobic polyurethane sponge.

[0069] Example 6

[0070] Step 1: In a three-necked flask, add polytetrahydrofuran glycol 25 g, water 1 g, dichloromethane 1 g, dibutyl tin dilaurate 0.4 g, dimethyl silicone oil 0.5 g, stir for 15 min under the condition of temperature 25 ℃ and stirring speed 200 r / min, to prepare the auxiliary material, i.e. component A;

[0071] Step 2: In a three-necked flask, add isophorone diisocyanate 50 g, stir for 30 min under the condition of temperature 60 ℃ and stirring speed 200 r / min, then add polytetrahydrofuran glycol 25 g, react for 3 h under the condition of temperature 70 ℃ and stirring speed 200 r / min, to prepare the prepolymer, i.e. component B;

[0072] Step 3: In a three-necked flask, add 5 g of nano-ZnO and 60 g of 80% ethanol aqueous solution, then add acetic acid dropwise until the pH value of the solution is 4. Ultrasonic treatment for 30 min, then add 1 g of N-β(aminoethyl)-γ-aminopropyl triethoxysilane dropwise under the condition of stirring speed 250 r / min, and condense reflux under the condition of temperature 60 ℃ and stirring speed 250 r / min. After reacting for 4 h, pour into a centrifuge tube and centrifuge at 10000 r / min for 20 min to obtain hydrophobic modified ZnO. Wash the modified ZnO with distilled water, suction filter 3 times, and vacuum dry at 70 ℃ for 24 h to constant weight, crush and pass through a 12500 mesh sieve to obtain hydrophobic modified ZnO powder, i.e. component C;

[0073] Step 4: In a three-necked flask, add 5 g of micron SiO2 and 60 g of 80% ethanol aqueous solution, then add acetic acid dropwise until the pH value of the solution is 4. Ultrasonic treatment for 30 min, then add 1 g of N-β(aminoethyl)-γ-aminopropyl triethoxysilane dropwise under the condition of stirring speed 250 r / min, and condense reflux under the condition of temperature 60 ℃ and stirring speed 250 r / min. After reacting for 4 h, pour into a centrifuge tube and centrifuge at 10000 r / min for 20 min to obtain hydrophobic modified SiO2. Wash the modified SiO2 with distilled water, suction filter 3 times, and vacuum dry at 60 ℃ for 24 h to constant weight, crush and pass through a 250 mesh sieve to obtain hydrophobic modified SiO2 powder, i.e. component D;

[0074] Step 5: According to the mass ratio of component A: component B: component C: component D being 50:100:15:15, the total mass being 50 g, component A, component B, component C and component D are weighed respectively and put into a flask in turn, and in-situ polymerization is carried out at temperature 20 ℃ and rotating speed 300 r / min for 30 min, then stirred at temperature 25 ℃ and rotating speed 1200 r / min for 30 s, to prepare the super-hydrophobic polyurethane;

[0075] Step 6: The super-hydrophobic polyurethane obtained in step 5 was poured into a mold and allowed to foam freely at 20℃ for 5 min, then the foamed polyurethane sponge was taken out and placed in an oven at 60℃ with a flow rate of 50 ml / min of flowing N2for 4 h to obtain the super-hydrophobic polyurethane sponge.

[0076] Example 7

[0077] Step 1: A three-necked flask was charged with polytetrahydrofuran glycol 25 g, water 1 g, dichloromethane 1 g, dibutyl tin dilaurate 0.4 g, dimethyl silicone oil 0.5 g, and stirred at a temperature of 25℃ and a stirring speed of 200 r / min for 15 min to prepare the auxiliary, i.e. component A;

[0078] Step 2: A three-necked flask was charged with isophorone diisocyanate 50 g, and stirred at a temperature of 60℃ and a stirring speed of 200 r / min for 30 min, then polytetrahydrofuran glycol 25 g was added, and reacted at a temperature of 70℃ and a stirring speed of 200 r / min for 3 h to prepare the prepolymer, i.e. component B;

[0079] Step 3: A three-necked flask was charged with 5 g of nano-ZnO and 60 g of 80% aqueous ethanol solution, then acetic acid was added dropwise until the pH value of the solution was 4. Ultrasonic treatment was performed for 30 min, then 1 g of N-β(aminoethyl)-γ-aminopropyl triethoxysilane was added dropwise under stirring at a speed of 250 r / min, and condensed reflux was performed at a temperature of 60℃ and a stirring speed of 250 r / min. After reacting for 4 h, it was poured into a centrifuge tube and centrifuged at a speed of 10000 r / min for 20 min to obtain hydrophobically modified ZnO. The modified ZnO was washed with distilled water, suction filtered 3 times, and vacuum dried at 70℃ for 24 h to a constant weight, then crushed and sieved through a 12500 mesh sieve to obtain hydrophobically modified ZnO powder, i.e. component C;

[0080] Step 4: A three-necked flask was charged with 5 g of micron-sized SiO2 and 60 g of 80% aqueous ethanol solution, then acetic acid was added dropwise until the pH value of the solution was 4. Ultrasonic treatment was performed for 30 min, then 1 g of N-β(aminoethyl)-γ-aminopropyl triethoxysilane was added dropwise under stirring at a speed of 250 r / min, and condensed reflux was performed at a temperature of 60℃ and a stirring speed of 250 r / min. After reacting for 4 h, it was poured into a centrifuge tube and centrifuged at a speed of 10000 r / min for 20 min to obtain hydrophobically modified SiO2. The modified SiO2 was washed with distilled water, suction filtered 3 times, and vacuum dried at 60℃ for 24 h to a constant weight, then crushed and sieved through a 250 mesh sieve to obtain hydrophobically modified SiO2 powder, i.e. component D;

[0081] Step 5: According to the mass ratio of component A: component B: component C: component D of 50:100:20:20, the total mass is 50 g, component A, component B, component C, and component D are weighed respectively, and put into a flask in sequence. After in-situ polymerization for 30 minutes at a temperature of 20°C and a speed of 300 r / min, the superhydrophobic polyurethane is obtained by stirring at a temperature of 25°C and a speed of 1200 r / min for 30 seconds.

[0082] Step 6: Pour the superhydrophobic polyurethane obtained in step 5 into a mold and perform free foaming reaction at 20°C for 5 minutes. Then take out the foamed polyurethane sponge and place it in a 60°C oven with flowing N2 at a flow rate of 50 ml / min for 4 hours to obtain a superhydrophobic polyurethane sponge.

[0083] Example 8

[0084] Step 1: Add 25 g of polytetrahydrofuran diol, 1 g of water, 1 g of dichloromethane, 0.4 g of dibutyltin dilaurate, and 0.5 g of dimethyl silicone oil into a three-necked flask, and stir at 25° C. and 200 rpm for 15 minutes to prepare an auxiliary material, i.e., component A;

[0085] Step 2: Add 50 g of isophorone diisocyanate to a three-necked flask, stir at 60° C. and 200 r / min, and stir for 30 min. Then add 25 g of polytetrahydrofuran diol, and react at 70° C. and 200 r / min for 3 h to obtain a prepolymer, i.e., component B.

[0086] Step 3: Add 5g of nano ZnO and 60g of 80% ethanol aqueous solution to a three-necked flask, and then add acetic acid dropwise until the pH value of the solution is 4. Ultrasonic treatment for 30min, then add 1g of N-β (aminoethyl) -γ-aminopropyl triethoxysilane dropwise at a stirring speed of 250r / min, and condense and reflux at a temperature of 70°C and a stirring speed of 250r / min. After reacting for 4h, pour into a centrifuge tube and centrifuge at a speed of 10000r / min for 20min to obtain hydrophobically modified ZnO. The modified ZnO was washed with distilled water, filtered 3 times, and vacuum dried at 70°C for 24h to constant weight, crushed, and passed through a 12500 mesh sieve to obtain hydrophobically modified ZnO powder, i.e. component C;

[0087] Step 4: 5 g of micron SiO2, 60 g of 80% ethanol aqueous solution were added into a three-necked flask, then acetic acid was added dropwise until the pH value of the solution was 4. After ultrasonic treatment for 30 min, 1 g of N-β(aminoethyl)-γ-aminopropyl triethoxysilane was added dropwise under the condition of stirring speed of 250 r / min and condensation reflux under the condition of temperature of 70 ℃ and stirring speed of 250 r / min. After reaction for 4 h, it was poured into a centrifuge tube and centrifuged at a speed of 10,000 r / min for 20 min to obtain hydrophobically modified SiO2. The modified SiO2 was washed with distilled water, suction filtered for 3 times, and vacuum dried at 60 ℃ for 24 h to a constant weight, crushed and passed through a 250 mesh sieve to obtain hydrophobically modified SiO2 powder, which was component D;

[0088] Step 5: 50 g of component A, component B, component C and component D were weighed according to the mass ratio of component A: component B: component C: component D of 50: 100: 5: 5, and sequentially put into a flask under the condition of temperature of 20 ℃ and stirring speed of 300 r / min for in-situ polymerization for 30 min, and then stirred at a temperature of 25 ℃ and a stirring speed of 1200 r / min for 30 s to prepare a super-hydrophobic polyurethane.

[0089] Step 6: The super-hydrophobic polyurethane obtained in step 5 was poured into a mold and subjected to a free foaming reaction at 20 ℃ for 5 min, and then the foamed polyurethane sponge was taken out and placed in a 60 ℃ oven with a flow rate of 50 ml / min of flowing N2 for 4 h to obtain a super-hydrophobic polyurethane sponge.

[0090] Example 9

[0091] Step 1: A three-necked flask was added with polytetrahydrofuran diol 25 g, water 1 g, dichloromethane 1 g, dibutyltin dilaurate 0.4 g, and dimethyl silicone oil 0.5 g, and stirred at a temperature of 25 ℃ and a stirring speed of 200 r / min for 15 min to prepare an auxiliary material, which was component A;

[0092] Step 2: Isophorone diisocyanate 50 g was added into a three-necked flask, and stirred at a temperature of 60 ℃ and a stirring speed of 200 r / min for 30 min, then polytetrahydrofuran diol 25 g was added, and reacted at a temperature of 70 ℃ and a stirring speed of 200 r / min for 3 h to prepare a prepolymer, which was component B;

[0093] Step 3: 5 g of nano-ZnO was added into 60 g of 80% aqueous ethanol solution in a three-necked flask, and then acetic acid was added dropwise until the pH value of the solution was 4. After ultrasonic treatment for 30 min, 1 g of N-β(aminoethyl)-γ-aminopropyl triethoxysilane was added dropwise under the condition of a stirring speed of 250 r / min, and then condensation reflux was carried out under the condition of a temperature of 80°C and a stirring speed of 250 r / min. After reaction for 4 h, the product was poured into a centrifuge tube and centrifuged at a speed of 10,000 r / min for 20 min to obtain hydrophobically modified ZnO. The modified ZnO was washed with distilled water and suction filtered for 3 times, and then vacuum dried at 70°C for 24 h to a constant weight. After crushing and sieving through a 12500-mesh screen, a hydrophobically modified ZnO powder, i.e., component C, was obtained.

[0094] Step 4: 5 g of micron-SiO2 was added into 60 g of 80% aqueous ethanol solution in a three-necked flask, and then acetic acid was added dropwise until the pH value of the solution was 4. After ultrasonic treatment for 30 min, 1 g of N-β(aminoethyl)-γ-aminopropyl triethoxysilane was added dropwise under the condition of a stirring speed of 250 r / min, and then condensation reflux was carried out under the condition of a temperature of 80°C and a stirring speed of 250 r / min. After reaction for 4 h, the product was poured into a centrifuge tube and centrifuged at a speed of 10,000 r / min for 20 min to obtain hydrophobically modified SiO2. The modified SiO2 was washed with distilled water and suction filtered for 3 times, and then vacuum dried at 60°C for 24 h to a constant weight. After crushing and sieving through a 250-mesh screen, a hydrophobically modified SiO2 powder, i.e., component D, was obtained.

[0095] Step 5: Components A, B, C and D were weighed according to a mass ratio of 50:100:5:5, and the total mass was 50 g. The components were sequentially put into a flask and subjected to in-situ polymerization at a temperature of 20°C and a speed of 300 r / min for 30 min, and then stirred at a temperature of 25°C and a speed of 1200 r / min for 30 s to prepare a super-hydrophobic polyurethane.

[0096] Step 6: The super-hydrophobic polyurethane obtained in step 5 was poured into a mold and subjected to a free foaming reaction at 20°C for 5 min. Then, the foamed polyurethane sponge was taken out and placed in a 60°C oven with a flow rate of 50 ml / min of flowing N2 for 4 h to obtain a super-hydrophobic polyurethane sponge.

[0097] Example 10

[0098] Step 1: A three-necked flask was charged with 25 g of polytetrahydrofuran diol, 1 g of water, 1 g of dichloromethane, 0.4 g of dibutyl tin dilaurate and 0.5 g of dimethyl silicone oil. The mixture was stirred at a temperature of 25°C and a stirring speed of 200 r / min for 15 min to prepare an auxiliary material, i.e., component A.

[0099] Step 2: In a three-necked flask, isophorone diisocyanate 50 g was added, stirred for 30 min at 60 ℃ and 200 r / min, then polytetramethylene glycol 25 g was added, reacted for 3 h at 70 ℃ and 200 r / min to obtain a prepolymer, i.e. component B;

[0100] Step 3: In a three-necked flask, 5 g of nano-ZnO and 60 g of 80% ethanol aqueous solution were added, then acetic acid was added dropwise until the pH value of the solution was 4. After ultrasonic treatment for 30 min, 1 g of N-β(aminoethyl)-γ-aminopropyl triethoxysilane was added dropwise at a stirring speed of 250 r / min, and condensed reflux was carried out at 60 ℃ and a stirring speed of 250 r / min. After reaction for 4 h, the mixture was poured into a centrifuge tube and centrifuged at 10,000 r / min for 20 min to obtain hydrophobically modified ZnO. The modified ZnO was washed with distilled water, suction filtered for 3 times, and vacuum dried at 70 ℃ for 24 h to a constant weight. After crushing and passing through a 12500-mesh sieve, hydrophobically modified ZnO powder, i.e. component C, was obtained;

[0101] Step 4: In a three-necked flask, 5 g of micron-SiO2 and 60 g of 80% ethanol aqueous solution were added, then acetic acid was added dropwise until the pH value of the solution was 4. After ultrasonic treatment for 30 min, 1 g of N-β(aminoethyl)-γ-aminopropyl triethoxysilane was added dropwise at a stirring speed of 250 r / min, and condensed reflux was carried out at 60 ℃ and a stirring speed of 250 r / min. After reaction for 4 h, the mixture was poured into a centrifuge tube and centrifuged at 10,000 r / min for 20 min to obtain hydrophobically modified SiO2. The modified SiO2 was washed with distilled water, suction filtered for 3 times, and vacuum dried at 60 ℃ for 24 h to a constant weight. After crushing and passing through a 250-mesh sieve, hydrophobically modified SiO2 powder, i.e. component D, was obtained;

[0102] Step 5: Components A, B, C and D were weighed according to the mass ratio of component A: component B: component C: component D = 50: 100: 5: 5, and the total mass was 50 g. The components were sequentially placed in a flask and subjected to in-situ polymerization at 20 ℃ and a stirring speed of 300 r / min for 30 min, and then stirred at 25 ℃ and a stirring speed of 1200 r / min for 30 s to obtain super-hydrophobic polyurethane;

[0103] Step 6: The super-hydrophobic polyurethane obtained in step 5 was poured into a mold and subjected to free foaming reaction at 30 ℃ for 5 min. Then the foamed polyurethane sponge was taken out and placed in a 60 ℃ oven with a flow rate of 50 ml / min of flowing N2 for 4 h to obtain a super-hydrophobic polyurethane sponge.

[0104] Example 11

[0105] Step 1: In a three-necked flask, add polytetrahydrofuran glycol 25 g, water 1 g, dichloromethane 1 g, dibutyl tin dilaurate 0.4 g, dimethyl silicone oil 0.5 g, stir for 15 min under the condition of temperature 25 ℃ and stirring speed 200 r / min, to prepare the auxiliary material, i.e. component A;

[0106] Step 2: In a three-necked flask, add isophorone diisocyanate 50 g, stir for 30 min under the condition of temperature 60 ℃ and stirring speed 200 r / min, then add polytetrahydrofuran glycol 25 g, react for 3 h under the condition of temperature 70 ℃ and stirring speed 200 r / min, to prepare the prepolymer, i.e. component B;

[0107] Step 3: In a three-necked flask, add 5 g of nano-ZnO and 60 g of 80% ethanol aqueous solution, then add acetic acid dropwise until the pH value of the solution is 4. Ultrasonic treatment for 30 min, then add 1 g of N-β(aminoethyl)-γ-aminopropyl triethoxysilane dropwise under the condition of stirring speed 250 r / min, and condense reflux under the condition of temperature 60 ℃ and stirring speed 250 r / min. After reacting for 4 h, pour into a centrifuge tube and centrifuge at 10000 r / min for 20 min to obtain hydrophobic modified ZnO. Wash the modified ZnO with distilled water, suction filter 3 times, and vacuum dry at 70 ℃ for 24 h to constant weight, crush and pass through a 12500 mesh sieve to obtain hydrophobic modified ZnO powder, i.e. component C;

[0108] Step 4: In a three-necked flask, add 5 g of micron SiO2 and 60 g of 80% ethanol aqueous solution, then add acetic acid dropwise until the pH value of the solution is 4. Ultrasonic treatment for 30 min, then add 1 g of N-β(aminoethyl)-γ-aminopropyl triethoxysilane dropwise under the condition of stirring speed 250 r / min, and condense reflux under the condition of temperature 60 ℃ and stirring speed 250 r / min. After reacting for 4 h, pour into a centrifuge tube and centrifuge at 10000 r / min for 20 min to obtain hydrophobic modified SiO2. Wash the modified SiO2 with distilled water, suction filter 3 times, and vacuum dry at 60 ℃ for 24 h to constant weight, crush and pass through a 250 mesh sieve to obtain hydrophobic modified SiO2 powder, i.e. component D;

[0109] Step 5: According to the mass ratio of component A: component B: component C: component D being 50:100:5:5, the total mass being 50 g, component A, component B, component C and component D are weighed respectively and put into a flask in turn, and in-situ polymerization is carried out at temperature 20 ℃ and rotating speed 300 r / min for 30 min, then stirred at temperature 25 ℃ and rotating speed 1200 r / min for 30 s, to prepare the super-hydrophobic polyurethane;

[0110] Step 6: The super-hydrophobic polyurethane obtained in step 5 was poured into a mold, and free foaming reaction was carried out at 40℃ for 5 min, then the foamed polyurethane sponge was taken out and placed in a 60℃ oven with flowing N2 at a flow rate of 50 ml / min for 4 h, to obtain the super-hydrophobic polyurethane sponge.

[0111] Comparative Example 1

[0112] Step 1: A three-necked flask was charged with polytetrahydrofuran glycol 25 g, water 1 g, dichloromethane 1 g, dibutyl tin dilaurate 0.4 g, dimethyl silicone oil 0.5 g, and stirred at a temperature of 25℃ and a stirring speed of 200 r / min for 15 min to prepare the auxiliary material, i.e. component A;

[0113] Step 2: A three-necked flask was charged with isophorone diisocyanate 50 g, and stirred at a temperature of 60℃ and a stirring speed of 200 r / min for 30 min, then polytetrahydrofuran glycol 25 g was added, and reacted at a temperature of 70℃ and a stirring speed of 200 r / min for 3 h to prepare the prepolymer, i.e. component B;

[0114] Step 3: Component A, component B, component C and component D were weighed according to the mass ratio of component A: component B: nano-ZnO: micro-SiO2 being 50:100:5:5, and the total mass being 50 g, and sequentially put into a flask, and in-situ polymerization was carried out at a temperature of 20℃ and a rotating speed of 300 r / min for 30 min, and then stirred at a temperature of 25℃ and a rotating speed of 1200 r / min for 30 s to prepare the super-hydrophobic polyurethane;

[0115] Step 4: The super-hydrophobic polyurethane obtained in step 3 was poured into a mold, and free foaming reaction was carried out at 20℃ for 5 min, then the foamed polyurethane sponge was taken out and placed in a 60℃ oven with flowing N2 at a flow rate of 50 ml / min for 4 h, to obtain the polyurethane sponge.

[0116] Comparative Example 2

[0117] Step 1: A three-necked flask was charged with polytetrahydrofuran glycol 25 g, water 1 g, dichloromethane 1 g, dibutyl tin dilaurate 0.4 g, dimethyl silicone oil 0.5 g, and stirred at a temperature of 25℃ and a stirring speed of 200 r / min for 15 min to prepare the auxiliary material, i.e. component A;

[0118] Step 2: A three-necked flask was charged with isophorone diisocyanate 50 g, and stirred at a temperature of 60℃ and a stirring speed of 200 r / min for 30 min, then polytetrahydrofuran glycol 25 g was added, and reacted at a temperature of 70℃ and a stirring speed of 200 r / min for 3 h to prepare the prepolymer, i.e. component B;

[0119] Step 3: 5 g of nano-ZnO was added into 60 g of 80% ethanol aqueous solution in a three-necked flask, and then acetic acid was added dropwise until the pH value of the solution was 4. After ultrasonic treatment for 30 min, 1 g of N-β(aminoethyl)-γ-aminopropyl triethoxysilane was added dropwise under the condition of stirring speed of 250 r / min, and was condensed and refluxed under the condition of temperature of 60°C and stirring speed of 250 r / min. After reaction for 4 h, it was poured into a centrifuge tube and centrifuged at a speed of 10,000 r / min for 20 min to obtain hydrophobically modified ZnO. The modified ZnO was washed with distilled water, suction filtered for 3 times, and vacuum dried at 70°C for 24 h to a constant weight. After being crushed and passed through a 12500-mesh sieve, hydrophobically modified ZnO powder was obtained, which was component C;

[0120] Step 4: Components A, B and C were weighed according to the mass ratio of component A: component B: component C of 50:100:5, and the total mass was 50 g. The components were sequentially placed into a flask under the condition of temperature of 20°C and stirring speed of 300 r / min for in-situ polymerization for 30 min, and then stirring at a temperature of 25°C and a speed of 1200 r / min for 30 s to prepare super-hydrophobic polyurethane.

[0121] Step 5: The super-hydrophobic polyurethane obtained in step 4 was poured into a mold, and free foaming reaction was carried out at 20°C for 5 min. Then the foamed polyurethane sponge was taken out and placed in a 60°C oven with a flow rate of 50 ml / min of flowing N2 for 4 h to obtain a polyurethane sponge.

[0122] Comparative Example 3

[0123] Step 1: A three-necked flask was added with polytetrahydrofuran glycol 25 g, water 1 g, dichloromethane 1 g, dibutyl tin dilaurate 0.4 g, and dimethyl silicone oil 0.5 g. After being fully stirred and mixed under the condition of temperature of 25°C, stirring speed of 200 r / min and stirring time of 15 min, an auxiliary material was prepared, which was component A.

[0124] Step 2: Isophorone diisocyanate 50 g was added into a three-necked flask. After stirring for 30 min under the condition of temperature of 60°C and stirring speed of 200 r / min, polytetrahydrofuran glycol 25 g was added. After being heated to 70°C, the mixture was reacted under the condition of stirring speed of 200 r / min and stirring time of 30 min for 3 h to prepare a prepolymer, which was component B.

[0125] Step 3: 5 g of micron SiO2 was added into 60 g of 80% ethanol aqueous solution in a three-necked flask, then acetic acid was added dropwise until the pH value of the solution was 4. After ultrasonic treatment for 30 min, 1 g of N-β(aminoethyl)-γ-aminopropyl triethoxysilane was added dropwise under the condition of stirring speed of 250 r / min and condensation reflux under the condition of temperature of 60 °C and stirring speed of 250 r / min. After reaction for 4 h, the product was poured into a centrifuge tube and centrifuged at a speed of 10,000 r / min for 20 min to obtain hydrophobically modified SiO2. The modified SiO2 was washed with distilled water, suction filtered for 3 times, and vacuum dried at 60 °C for 24 h to a constant weight, then crushed and sieved through a 250 mesh sieve to obtain hydrophobically modified SiO2 powder, which was component C;

[0126] Step 4: 50 g of component A, component B and component C were weighed according to the mass ratio of component A: component B: component C of 50: 100: 5, and sequentially put into a flask to perform in-situ polymerization under the condition of temperature of 20 °C and stirring speed of 300 r / min for 30 min, and then stirred at a temperature of 25 °C and a stirring speed of 1200 r / min for 30 s to obtain super-hydrophobic polyurethane.

[0127] Step 5: The super-hydrophobic polyurethane obtained in step 4 was poured into a mold to perform free foaming reaction at 20 °C for 5 min, then the foamed polyurethane sponge was taken out and placed in a 60 °C oven with a flow rate of 50 ml / min of flowing N2 for 4 h to obtain a polyurethane sponge.

[0128] Effect verification

[0129] To fully understand the performance of the modified polyurethane sponge prepared in each example and comparative example, water contact angle test, adsorption capacity test, adsorption capacity test after 10 times of recycling and 100 times of recycling were performed, wherein the water contact angle test was performed according to GB / T 30693-2014; the adsorption capacity test was performed by weighing method to study the adsorption capacity of the super-hydrophobic polyurethane sponge to kerosene. The super-hydrophobic polyurethane sponge with different proportions was cut into multiple small cubes with a size of 1.0 cm x 1.0 cm x 1.0 cm, the mass of the sponge itself was weighed and recorded as m0. Different sponges were respectively immersed in a beaker containing 30 mL of kerosene, soaked for 24 h to reach adsorption saturation, then the sponge was taken out and the excess oil drops on the surface of the sponge were drained, the mass of the sponge was detected by a weighing balance and recorded as m1, and the adsorption capacity Q of the sponge to kerosene was calculated according to the formula Q = m1 / m0. The adsorption capacity test after 10 times of recycling and 100 times of recycling was the same as the above adsorption capacity test method, and the adsorption capacity Q of the sponge was calculated after recording the oil absorption-oil release experiment for 10 and 100 times of recycling. The test results are shown in Table 1.

[0130] Table 1 Performance test results

[0131]

[0132] From the analysis of the data in Table 1, it can be seen that the hydrophobicity and the adsorption capacity of kerosene of the polyurethane sponge prepared from the modified nano-ZnO and micro-SiO2 (Example 4) is greatly improved compared with the polyurethane sponge prepared from the unmodified nano-ZnO and micro-SiO2 (Comparative Example 1). The hydrophobicity of the polyurethane sponge prepared from the combination of nano-ZnO and micro-SiO2 (Example 4) is better than that of the sponge prepared from a single particle (Comparative Examples 2 and 3). In the above examples, the water contact angle and the adsorption capacity of diesel of Example 7 are the best.

[0133] With the increase of the chain length of the silane compound (Examples 1 to 4), the water contact angle, the adsorption capacity of kerosene, the adsorption capacity after 10 cycles and the adsorption capacity after 100 cycles of the polyurethane sponge are all increased, and the best performance is obtained with N-β(aminoethyl)-γ-aminopropyl triethoxysilane (Example 4). The reason is that with the increase of the chain length of the silane compound, the surface energy of the silane compound is reduced, thereby increasing the water contact angle and the adsorption capacity of diesel of the polyurethane sponge.

[0134] With the increase of the content of the modified nano-ZnO and micro-SiO2 (Examples 4 to 7), the water contact angle, the adsorption capacity of diesel, the adsorption capacity after 10 cycles and the adsorption capacity after 100 cycles of the polyurethane sponge are all increased. The performance of the super-hydrophobic polyurethane sponge is the best when the mass fraction of nano-ZnO and micro-SiO2 is 20 parts (Example 7). The reason is that with the increase of the content of the modified nano-ZnO and micro-SiO2, the content of nano-ZnO and micro-SiO2 on the surface and inside of the polyurethane sponge is increased, the micro-nano composite structure formed on the surface and inside of the sponge is increased, the roughness of the surface of the polyurethane sponge is increased, and the water contact angle and the adsorption capacity of kerosene of the polyurethane sponge are improved.

[0135] With the increase of the temperature for modification of nano-ZnO and micro-SiO2 (Example 4, Example 8 and Example 9), the water contact angle, the adsorption capacity of diesel, the adsorption capacity after 10 cycles and the adsorption capacity after 100 cycles of the polyurethane sponge are all decreased. When the temperature for modification of nano-ZnO and micro-SiO2 is 60°C (Example 4), the hydrophobicity and the adsorption capacity of kerosene of the polyurethane sponge are the best.

[0136] As the foaming temperature rises (Example 4, Example 10, Example 11), the water contact angle of the polyurethane sponge, the adsorption capacity for diesel oil, the adsorption capacity after 10 cycles, and the adsorption capacity after 100 cycles decrease. The contact angle and the adsorption capacity for diesel oil of the polyurethane sponge are best when the foaming temperature is 20℃ (Example 4).

[0137] In summary, the present application provides a long-acting super-hydrophobic polyurethane sponge and a preparation method thereof. A silane compound is used to treat nano-ZnO and micro-SiO2 to reduce the surface energy of the nano-ZnO and micro-SiO2 and improve the hydrophobicity. The hydrophobically modified nano-ZnO and the hydrophobically modified micro-SiO2 are added to a polyurethane prepolymer prepared from polyol and polyisocyanate and the like to uniformly mix and perform in-situ polymerization to obtain a super-hydrophobic polyurethane. The super-hydrophobic polyurethane is then foamed freely in a mold to obtain a long-acting super-hydrophobic polyurethane sponge. On the one hand, the surface of the nano-ZnO and micro-SiO2 powder is treated with the silane compound to introduce a long-chain silane molecule onto the surface of the nano-ZnO and micro-SiO2 powder, which not only improves the interaction between the nano-ZnO and micro-SiO2 powder and the polyurethane molecule through covalent bond to prevent the powder from falling off the polyurethane, but also reduces the surface energy of the powder to improve the hydrophobicity of the polyurethane sponge and further improve the oil absorption efficiency of the polyurethane sponge. On the other hand, the nano-ZnO and micro-SiO2 are uniformly distributed in the polyurethane sponge obtained by in-situ polymerization and foaming to form a micro-nano composite structure on the surface and inside of the sponge to improve the mesoscopic roughness of the polyurethane sponge. Moreover, when the surface micro-nano composite structure is worn out due to long-term use, the micro-nano composite structure inside the sponge will be exposed to the surface of the sponge, which ensures that the micro-nano composite structure with high roughness always exists on the surface of the sponge, thereby solving the problem of easy damage of the micro-nano composite structure and prolonging the service life of the super-hydrophobic function of the polyurethane sponge. The polyurethane sponge forms and continuously maintains the super-hydrophobic performance under the combined action of the above-mentioned low surface energy and micro-nano rough structure, thereby having the function of long-term and high-efficiency oil-water separation.

[0138] The polyurethane sponge with long-term and high-efficiency oil-water separation capacity can be used to efficiently remove oil stains floating on the surface of the sea, lake and the like. Specifically, the long-acting super-hydrophobic polyurethane sponge is put into an oil-stained water area, the oil stains on the water surface are adsorbed by the long-acting super-hydrophobic polyurethane sponge, and then the long-acting super-hydrophobic polyurethane sponge is fished up and collected to separate the oil stains by centrifugation or extrusion, and the regenerated sponge after separation of the oil stains is put into the next round of use. This method for removing oil stains on the water surface uses the long-acting super-hydrophobic polyurethane sponge to efficiently adsorb oil pollutants to realize rapid oil-water separation, and the sponge can be recycled, which is helpful to continuously improve the water quality and ecological environment.

[0139] Of course, the present application can have various embodiments, and those skilled in the art can make various corresponding changes and modifications according to the disclosure of the present application without departing from the spirit and essence of the present application, and these corresponding changes and modifications shall all belong to the protection scope of the claims of the present application.

Claims

1. A method for preparing a long-lasting super-hydrophobic polyurethane sponge, characterized in that: The following steps are involved: Step 1: 50-80 parts by mass of polyol, 2-3 parts by mass of water, 1-4 parts by mass of foaming agent, 0.5-1.5 parts by mass of catalyst, and 0.4-1 part by mass of foam stabilizer are mixed uniformly at a temperature of 15-30° C. to prepare a polyurethane auxiliary material, i.e., component A; Step 2: Add 50-75 parts by mass of polyisocyanate to a reaction vessel, stir at a temperature of 60-80° C. for 20-40 minutes, then add polyol at a mass ratio of polyisocyanate to polyol of 100:40-100:75, and react at a temperature of 60-80° C. to obtain a polyurethane prepolymer, i.e., component B; Step 3: Disperse 5-20 parts by mass of nano-ZnO in 60-80 parts by mass of a solvent, then dropwise add 1-3 parts by mass of a silane compound, and react at a temperature of 60-80°C for 3-6 hours. Then, separate the solid, wash, and dry it to obtain a hydrophobically modified ZnO powder, i.e., component C. Step 4: Disperse 5-20 parts by mass of micronized SiO2 in 60-80 parts by mass of a solvent, then dropwise add 1-3 parts by mass of a silane compound, and react at a temperature of 60-80°C for 3-6 hours. Then, separate the solid, wash, and dry it to obtain a hydrophobically modified SiO2 powder, i.e., component D. Step 5: Component A, component B, component C, and component D are mixed in a mass ratio of component A: component B: component C: component D of 45-55:100:5-20:5-20, and an in-situ polymerization reaction is performed to prepare a super-hydrophobic polyurethane; Step 6: Pour the super-hydrophobic polyurethane obtained in the above step 5 into a mold, perform free foaming reaction, and after drying, obtain a long-lasting super-hydrophobic polyurethane sponge; The silane compound is one or more of 3-aminopropyltriethoxysilane, 3-aminopropyltrimethoxysilane, N-β (aminoethyl) -γ-aminopropyltrimethoxysilane, N-β (aminoethyl) -γ-aminopropylmethyldimethoxysilane, and N-β (aminoethyl) -γ-aminopropyltriethoxysilane.

2. The method for preparing a long-acting super-hydrophobic polyurethane sponge according to claim 1, wherein: In step 3, 5 to 20 parts by mass of nano-ZnO are added to 60 to 80 parts by mass of 80% ethanol aqueous solution, and then acetic acid is added dropwise until the pH value of the solution is 4. After mixing, 1 to 3 parts by mass of a silane compound is added dropwise under stirring conditions, and the reaction is carried out at a temperature of 60 to 80° C. for 3 to 6 hours. The solid is then separated by centrifugation, washed with distilled water, and filtered, and the washing and filtration steps are repeated 1 to 4 times. The filtered solid is vacuum dried at 60° C. to constant weight, crushed, and sieved to obtain a hydrophobically modified ZnO powder, i.e., component C.

3. The preparation method of the long-acting super-hydrophobic polyurethane sponge according to claim 1, wherein: In step 4, 5 to 20 parts by mass of nano-SiO2 are added to 60 to 80 parts by mass of 80% ethanol aqueous solution, and then acetic acid is added dropwise until the pH value of the solution is 4. After mixing, 1 to 3 parts by mass of silane compound are added dropwise under stirring conditions, and the reaction is carried out at a temperature of 60 to 80°C for 3 to 6 hours. The solid is then separated by centrifugation, washed with distilled water and filtered, and the washing and filtration steps are repeated 1 to 4 times. The filtered solid is vacuum dried at 60°C to constant weight, crushed and sieved to obtain hydrophobically modified SiO2 powder, i.e., component D.

4. The method for preparing a long-acting super-hydrophobic polyurethane sponge according to claim 1, wherein: In step 5, by component A: component B: component C: the mass ratio of component D is 50:100:5~20:5~20, component A, component B, component C and component D are weighed respectively and placed in reaction vessel, at temperature is 20~40 DEG C, under rotating speed 200~300r / min, after carrying out in-situ polymerization 10~30min, at temperature is 20~40 DEG C, under rotating speed 1000~1500r / min, stir 15~30s, obtained described super-hydrophobic polyurethane.

5. The method for preparing a long-acting super-hydrophobic polyurethane sponge according to claim 1, wherein: In step 6, the super-hydrophobic polyurethane obtained in step 5 is poured into a mold, and a free foaming reaction is carried out at 20-40° C. for 3-5 minutes. Then, the foamed polyurethane sponge is taken out and placed in a 60-80° C. oven with a flow rate of 50 ml / min of flowing N2 and dried for 3-6 hours to obtain the long-lasting super-hydrophobic polyurethane sponge.

6. The method for preparing a long-lasting super-hydrophobic polyurethane sponge according to claim 1, wherein: The polyol in step 1 and step 2 is one or more of polytetrahydrofuran diol, polycarbonate diol, polycaprolactone diol and polypropylene glycol.

7. The method for preparing a long-lasting super-hydrophobic polyurethane sponge according to claim 1, wherein: The foaming agent in step 1 is one or more of dichloromethane, 1,1,1,3,3-pentafluorobutane, 1,1,1,3,3-pentafluoropropane, 1,1,1,2-tetrafluoroethane, difluoroethane, and heptafluoropropane; and / or The catalyst in step 1 is selected from an organometallic catalyst and a tertiary amine catalyst, wherein the organometallic catalyst is one or more of dibutyltin dilaurate, stannous octoate, and dibutyltin acetate; and / or The foam stabilizer in step 1 is one or more of dimethyl silicone oil, dodecyl dimethyl amine oxide, and alkyl alcohol amide; and / or The polyisocyanate in step 2 is one or more of isophorone diisocyanate, hexamethylene diisocyanate, and toluene diisocyanate.

8. The method for preparing a long-lasting super-hydrophobic polyurethane sponge according to claim 1, wherein: The nano ZnO particle size in step 3 is 50-300 nm; and / or The micron SiO2 particle size in step 4 is 50~300μm.

9. A long-lasting super-hydrophobic polyurethane sponge, characterized in that: The method is prepared according to any one of claims 1 to 8.

10. A method for removing oil pollution from a water surface, characterized in that: The long-lasting super-hydrophobic polyurethane sponge described in claim 9 is placed in an oily wastewater area. After the oil on the water surface is adsorbed by the long-lasting super-hydrophobic polyurethane sponge, it is salvaged and collected, and the oil is separated by centrifugation or squeezing. The regenerated sponge after the oil is separated is put into the next round of use.

Images