Asphalt-based hydrophobic oil-absorbing sponge as well as preparation method and application thereof

Abstract

The invention discloses an asphalt-based hydrophobic oil-absorbing sponge as well as a preparation method and application thereof. The asphalt-based hydrophobic oil-absorbing sponge is obtained by adsorbing cross-linked asphalt resin by a sponge and then curing, the cross-linked asphalt resin is formed by cross-linking asphalt and benzaldehyde under the catalysis of strong protonic acid. The asphalt-based hydrophobic oil absorption sponge has good oil absorption efficiency, and the oil absorption amount exceeds 40 times of the self weight. In addition, about 40 times of oil absorption efficiency can still be maintained after 10 times of circulation, which indicates that the crosslinked asphalt resin can be stably loaded on the sponge body. Compared with the prior art, the asphalt which is wide in source and low in price is adopted as the main raw material of the modifier, the cost is effectively reduced, the preparation method is simple, and wide application prospects are achieved.

Description

Technical Field

[0001] This invention belongs to the field of sponge modification technology, specifically relating to an asphalt-based hydrophobic oil-absorbing sponge, its preparation method, and its application. Background Technology

[0002] In industrial production processes, problems such as organic solvent leakage and oily wastewater discharge have further aggravated water pollution, making the research and development of high-efficiency oil-absorbing materials a hot topic in the field of environmental functional materials.

[0003] Oil spill treatment methods mainly include dispersion, coagulation, and adsorption. Among these, adsorption, with its advantages of simple operation, environmental friendliness, and high recovery efficiency, has become the most commonly used method for treating oil spills. Among various adsorbent materials, sponge materials, due to their high porosity and compressibility, show great application potential in the oil absorption field. However, conventional polymer sponges, such as polyurethane or melamine sponges, lack selective absorption of oil and water, requiring hydrophobic treatment of the sponge skeleton surface to achieve oil absorption. For example, patent CN104163934 A discloses a method of partially carbonizing the surface of a sponge material to obtain a hydrophobic and oleophilic material; patent CN 111592683 B discloses a method of modifying the sponge skeleton surface with inorganic nanoparticles to achieve hydrophobic and oleophilic effects; and patent CN 104771936 A discloses a method of modifying the sponge skeleton surface with silane modifiers. Although these modification strategies achieve both hydrophobicity and oil absorption functions in the sponge, they often involve complex preparation processes and expensive modifiers. Therefore, it is of great significance to develop inexpensive modifiers to reduce the cost of sponge modification while ensuring the oil absorption efficiency of the sponge. Summary of the Invention

[0004] One of the objectives of this invention is to provide an asphalt-based hydrophobic oil-absorbing sponge, which is obtained by hydrophobically modifying a sponge with inexpensive and widely available asphalt. It has good oil absorption efficiency and stability, and also has the advantages of simple preparation and low production cost.

[0005] Accordingly, the present invention also provides a method for preparing and applying the above-mentioned asphalt-based hydrophobic oil-absorbing sponge.

[0006] The technical solution of the present invention is as follows:

[0007] A bitumen-based hydrophobic oil-absorbing sponge is obtained by adsorbing cross-linked bitumen resin into a sponge and then curing it.

[0008] Cross-linked asphalt resin is formed by cross-linking asphalt and benzaldehyde under the catalysis of strong protic acids.

[0009] A method for preparing the above-mentioned bitumen-based hydrophobic oil-absorbing sponge includes the following steps:

[0010] (1) asphalt and benzaldehyde are crosslinked under the catalysis of strong protonic acid to obtain crosslinked asphalt resin, wherein the addition amount of benzaldehyde is 5-25wt% of asphalt, the crosslinking reaction temperature is 125-135 DEG C, and the crosslinking reaction is completed when the viscosity of the system increases and the rod winding phenomenon occurs;

[0011] (2) the crosslinked asphalt resin is dissolved in an oily solvent to obtain a modified solution;

[0012] (3) the sponge is immersed in the modified solution to adsorb the modified solution;

[0013] (4) the adsorbed sponge is cured to obtain asphalt-based hydrophobic oil-absorbing sponge.

[0014] In some preferred embodiments, the crosslinking reaction time is 55-65 min.

[0015] In some preferred embodiments, the curing temperature is 175-185 DEG C, and the curing time is 55-65 min.

[0016] In some preferred embodiments, the strong protonic acid is concentrated sulfuric acid, and the addition amount of concentrated sulfuric acid is 8-12wt% of asphalt.

[0017] In some preferred embodiments, the mass-volume ratio of crosslinked asphalt resin to oily solvent is 1g:10-40mL.

[0018] In some preferred embodiments, step (4) further comprises: before curing, the adsorbed sponge is dried at 55-75 DEG C for 2.5-3.5h.

[0019] In some preferred embodiments, the oily solvent is kerosene.

[0020] In some preferred embodiments, the sponge is melamine sponge.

[0021] The above asphalt-based hydrophobic oil-absorbing sponge is used in the treatment of oily wastewater or the recovery of spilled oil at sea.

[0022] The present application has at least the following beneficial effects:

[0023] 1. The asphalt-based hydrophobic oil-absorbing sponge has good oil absorption efficiency, and the oil absorption amount is more than 40 times the weight. In addition, it can still maintain an oil absorption efficiency of about 40 times after 10 cycles, indicating that the crosslinked asphalt resin can be stably loaded on the sponge body.

[0024] 2. Compared with the prior art, the present application uses widely available and low-cost asphalt as the main raw material for modification, effectively reduces the cost and has a simple preparation method, and has a wide application prospect. BRIEF DESCRIPTION OF DRAWINGS

[0025] Figure 1 The photos of asphalt-based modified sponge and oil absorption modified by 10wt% modification solution in Example 1 are shown, A is the photo of unmodified sponge, B is the photo of asphalt-based hydrophobic oil absorption sponge, C is the photo of aviation oil, and D is the photo of asphalt-based hydrophobic oil absorption sponge after absorbing aviation oil in C;

[0026] Figure 2 The scanning electron microscope photos of sponge and asphalt-based modified sponge modified by 10wt% modification solution in Example 1 are shown, wherein A and B are sponges, and C and D are asphalt-based modified sponges.

[0027] Figure 3 The change graph of hydrophobicity and repeated oil absorption efficiency of modified sponge modified by different concentrations of modification agent in Example 1 is shown. DETAILED DESCRIPTION

[0028] The technical solutions of the present application are further described and explained in the following specific embodiments.

[0029] In the following examples, if not specifically stated, the water used can be one or more of distilled water, purified water, drinking water; the detection methods in the following examples, if not specifically stated, are all conventional detection methods; the reagents in the following examples, if not specifically stated, are all purchased from commercial channels.

[0030] The "rod winding phenomenon" referred to in the present application means that as the reaction proceeds, the viscosity of the system increases significantly, and the system changes from a flowable liquid to a state with viscoelasticity, and when the stirring rod is lifted, the material can adhere to the rod body and is not easy to drop.

[0031] Example 1

[0032] (1) 50 g of asphalt was heated to 130℃ in a three-necked flask, and when the molten asphalt could flow smoothly under stirring, 12.5 g of crosslinking agent benzaldehyde was added, and the mixture was stirred at 300 r / min and heated at 130℃ for 60 min, and then 5 g of concentrated sulfuric acid was slowly added dropwise. The asphalt and benzaldehyde were crosslinked under the catalysis of concentrated sulfuric acid, the viscosity of the sample increased, and the rod winding phenomenon occurred. The reaction sample was taken out, and a crosslinked asphalt resin was obtained.

[0033] (2) 5 g of the crosslinked asphalt resin was weighed into a beaker, and 50 ml, 100 mL and 200 mL of kerosene were added respectively, and ultrasonic dissolution was performed for 15 min to prepare a modification solution with a crosslinked asphalt resin concentration of 10wt%, 5wt% and 2.5wt%.

[0034] (3) melamine sponge (2x2x2cm) was soaked in the modified solution, after the sponge was soaked completely, the excess modified solution was squeezed out, then placed in the oven at 60℃ for drying 3h, finally the temperature was increased to 180℃ for further curing 1h, to obtain the asphalt-based hydrophobic oil-absorbing sponge.

[0035] As shown in Figure 1 , the white melamine sponge quickly absorbs water and sinks to the bottom of the water (A) due to its hydrophilicity, while the black asphalt-based hydrophobic oil-absorbing sponge (10wt% modified solution) shows strong hydrophobicity and can stably float on the water surface (B). Add red aviation oil to the water surface, and then put the asphalt-based hydrophobic oil-absorbing sponge into the system, the asphalt-based hydrophobic oil-absorbing sponge can absorb all the aviation oil (D).

[0036] Figure 2 The electron microscope photos of the sponge before modification (A, B) and the asphalt-based hydrophobic oil-absorbing sponge after modification by 10wt% modified solution (C, D) are shown, it can be seen that the modified asphalt-based hydrophobic oil-absorbing sponge still has high porosity, and the surface of the skeleton is uniformly covered with crosslinked asphalt resin.

[0037] The weights of the asphalt-based hydrophobic oil-absorbing sponge modified by 10wt%, 5wt% and 2.5wt% modified solution were measured, then enough aviation oil was taken to fully absorb the asphalt-based hydrophobic oil-absorbing sponge, and then weighed, then the aviation oil in the asphalt-based hydrophobic oil-absorbing sponge was squeezed out, and then adsorbed again, repeated 10 times, and the oil absorption efficiency of the sponge was calculated. As shown in Figure 3 , the oil absorption efficiency of the modified sponge increases with the increase of the concentration of the modifier, but the oil absorption efficiency of the three groups of asphalt-based hydrophobic oil-absorbing sponge is more than 40 times the weight, and after repeated use for 10 times, the oil absorption efficiency does not decrease significantly.

[0038] The above is only a preferred embodiment of the present application, and therefore cannot limit the scope of the present application, i.e. equivalent changes and modifications made according to the scope of the present patent and the content of the specification shall still be within the scope covered by the present application.

Claims

1. An asphalt-based hydrophobic oil-absorbing sponge, characterized by, obtained by curing the sponge after adsorbing the crosslinked asphalt resin; the crosslinked asphalt resin is obtained by crosslinking asphalt and benzaldehyde under the catalysis of strong protonic acid.

2. A process for the preparation of bitumen-based hydrophobic oil-absorbing sponges according to claim 1, characterized in that, comprising the following steps: (1) crosslinking reaction of asphalt and benzaldehyde under the catalysis of strong protonic acid, wherein the addition amount of benzaldehyde is 5-25wt% of asphalt, the temperature of crosslinking reaction is 125-135℃, and the sign of completion of crosslinking reaction is the increase of system viscosity and the occurrence of rod winding phenomenon; (2) dissolving the crosslinked asphalt resin in oil solvent to obtain modified solution; (3) immersing sponge in the modified solution to adsorb the modified solution; (4) curing treatment of the adsorbed sponge to obtain the asphalt-based hydrophobic oil-absorbing sponge.

3. The production method according to claim 2, wherein The time of crosslinking reaction is 55-65min.

4. The production method according to claim 2, wherein The temperature of curing treatment is 175-185℃, and the time of curing treatment is 55-65min.

5. The production method according to claim 2, wherein The strong protonic acid is concentrated sulfuric acid, and the addition amount of concentrated sulfuric acid is 8-12wt% of asphalt.

6. The production method according to claim 2, wherein The mass-volume ratio of crosslinked asphalt resin to oil solvent is 1g:10-40mL.

7. The production method according to claim 2, wherein Step (4) further comprises: before curing treatment, drying the adsorbed sponge at 55-75℃ for 2.5-3.5h.

8. The production method according to claim 2, wherein The oil solvent is kerosene.

9. The production method according to claim 2, wherein The sponge is melamine sponge.

10. Application of the asphalt-based hydrophobic oil-absorbing sponge of claim 1 in treating oily wastewater or recovering marine oil spill.

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