Water-retaining material and method for vegetation restoration in arid regions

Abstract

The application relates to the field of water-retaining materials, in particular to a water-retaining material and a method for vegetation restoration in arid regions, which comprises inorganic components and organic components; the organic components are obtained by copolymerization of ionic liquids, acrylic monomers and N,N-methylene bisacrylamide; the water-retaining material prepared by the application has strong water absorption capacity, the water absorption multiple can reach more than 700 times, the water-retaining capacity is excellent, water can be released for a long time, and the water-retaining material can be applied to vegetation restoration in arid regions.

Description

Technical Field

[0001] This invention relates to the field of water-retaining materials, specifically to a water-retaining material and a method for vegetation restoration in arid regions. Background Technology

[0002] Due to the influence of climate and human activities, soil erosion and desertification are very serious in some areas, which restricts the sustainable development of local society and economy. Vegetation restoration is one of the important means to solve soil erosion and desertification.

[0003] Vegetation restoration applies ecological principles to improve ecosystems and biodiversity through measures such as forest closure for natural regeneration, environmental improvement, agroforestry, and other restoration initiatives. Vegetation restoration can effectively improve soil nutrients, moisture, and structure, thereby enhancing soil quality, and also has a significant impact on the local environment.

[0004] Research on water conservation measures during vegetation planting and maintenance in arid regions is relatively limited. Without appropriate water conservation measures, artificial vegetation establishment in arid areas can lead to difficulties and low survival rates. Currently, the most commonly used water-retaining materials are various types of water-retaining agents. These agents are synthetic polymers that can absorb hundreds of times their own weight in water, providing moisture to vegetation through repeated absorption and release. The urgent issue is how to improve the water absorption and retention properties of these materials to enhance their effectiveness in vegetation restoration in arid regions. Summary of the Invention

[0005] Purpose of the invention: In view of the above-mentioned technical problems, the present invention proposes a water-retaining material and a method for vegetation restoration in arid areas.

[0006] The technical solution adopted is as follows:

[0007] A water-retaining material comprising inorganic and organic components;

[0008] The organic component is obtained by copolymerization of ionic liquid, acrylic monomer and N,N-methylenebisacrylamide.

[0009] Furthermore, the inorganic component is attapulgite.

[0010] Furthermore, the attapulgite clay undergoes epoxidation modification treatment.

[0011] Furthermore, the preparation method of the above-mentioned water-retaining material is as follows:

[0012] Under nitrogen protection, inorganic components are dispersed in an organic solvent, and then ionic liquid, acrylic monomers, N,N-methylenebisacrylamide and free radical initiator are added. The mixture is heated to reflux for 5-15 hours and then returned to room temperature. Sodium hydroxide solution is added, the mixture is stirred and filtered, and the product is collected, washed and dried.

[0013] Furthermore, the ionic liquid is an allyl imidazole amino acid salt ionic liquid.

[0014] Further, the allyl imidazole amino acid salt ionic liquid is any one or a combination of 1-allyl-3-methylimidazolium glycine salt, 1-allyl-3-methylimidazolium glutamate salt, 1-allyl-3-methylimidazolium valine salt, 1-allyl-3-methylimidazolium serine salt, 1-allyl-3-methylimidazolium lysine salt, 1-allyl-3-methylimidazolium arginine salt, and 1-allyl-3-methylimidazolium aspartate salt.

[0015] Furthermore, the acrylic monomers include acrylic acid and methyl methacrylate;

[0016] The mass ratio of acrylic acid to methyl methacrylate is 1-5:1-5.

[0017] Furthermore, the mass ratio of the inorganic component, ionic liquid, and acrylic monomer is 1:5-10:80-100.

[0018] Furthermore, the free radical initiator is any one or more combinations of cyclohexanone peroxide, benzoyl peroxide, tert-butyl hydroperoxide, azobisisobutyronitrile, and azobisisoheptanenitrile.

[0019] The present invention also provides a method for vegetation restoration in arid areas, specifically, when planting seedlings, the above-mentioned water-retaining material is mixed with the soil dug out from the planting pit and then used as fill soil for planting seedlings.

[0020] The beneficial effects of this invention are:

[0021] This invention proposes a water-retaining material. Compared with the prior art, this invention introduces the copolymerization of ionic liquid and acrylic monomers. The hydrophilic groups contained in the ionic liquid can not only improve the water absorption and water retention effect of the water-retaining material, but also improve the microstructure of the water-retaining material through free radical polymerization and the reaction of amino and epoxy groups, so that it presents a porous interpenetrating network structure. This structure is similar to a "miniature reservoir" and has more beneficial water absorption, water locking and water retention properties.

[0022] The addition of attapulgite can give the water-retaining material a cross-linked organic-inorganic hybrid structure. On the one hand, it can give the water-retaining material a good gel morphology after water absorption, so that it has a long-term water retention capacity. On the other hand, the use of water-retaining material for vegetation restoration in arid areas can improve the physical and chemical properties of the soil, reduce soil bulk density and non-capillary porosity, and improve the soil's water holding capacity.

[0023] The literature "Effects of Pretreatment of Corn Straw and Treatment Residue on Tomato Growth with Amino Acid Ionic Liquid" indicates that low concentrations of imidazole ionic liquid amino acid salts do not significantly affect the growth of corn seedlings, and the growth of tomato plants, such as plant height and stem diameter, are significantly improved. The total amount of chlorophyll, the activity of antioxidant enzymes and MDA content in the roots, soil enzyme activity, and the number of microorganisms in the soil are also increased. Therefore, the water-retaining material provided in this application may also have a certain promoting effect on vegetation growth. However, the specific toxic effects on plants and organisms and its application in vegetation restoration in arid areas still need to be verified through long-term planting experiments.

[0024] The water-retaining material prepared by this invention has a strong water absorption capacity, with a water absorption ratio of over 700 times. Moreover, it has excellent water retention capacity and can release water for a long time, making it suitable for vegetation restoration in arid regions. Detailed Implementation

[0025] Unless otherwise specified in the examples, the conditions were performed under standard conditions or as recommended by the manufacturer. Reagents or instruments whose manufacturers are not specified are all commercially available products. Techniques not mentioned in this invention refer to existing technologies. Unless otherwise specified, the following examples and comparative examples are parallel experiments, using the same processing steps and parameters.

[0026] Example 1:

[0027] A water-retaining material comprising an epoxidized modified attapulgite and a copolymer of 1-allyl-3-methylimidazolium lysine, acrylic acid, methyl methacrylate, and N,N-methylenebisacrylamide.

[0028] The preparation method of the above-mentioned water-retaining material is as follows:

[0029] 10g of attapulgite was dispersed in 100ml of acetone, 1g of KH560 was added dropwise, the mixture was sonicated for 30min, then heated to reflux and stirred for 5h, filtered, the product was collected and washed with anhydrous ethanol and deionized water, and then dried under vacuum at 60℃ for 24h to obtain epoxidized modified attapulgite.

[0030] Lysine and potassium hydroxide were mixed in a 1:1 molar ratio to prepare an aqueous solution of amino acid salt. The mixture was added dropwise to an equal amount of 1-allyl-3-methylimidazolium chloride. After stirring and reacting at 80°C for 5 hours, the mixture was filtered. The filtrate was distilled under reduced pressure to remove water to obtain a crude product. Ten times the mass of anhydrous ethanol was added to the crude product. After stirring thoroughly, the solid was removed by filtration. The filtrate was then distilled under reduced pressure to obtain 1-allyl-3-methylimidazolium lysine salt.

[0031] Under nitrogen protection, 1g of epoxidized attapulgite was dispersed in 500ml of ethanol, followed by 5g of 1-allyl-3-methylimidazolium lysine salt, 50g of acrylic acid, 45g of methyl methacrylate, 1g of N,N-methylenebisacrylamide, and 0.02g of benzoyl peroxide. The mixture was heated to reflux and reacted for 10h, then returned to room temperature. 500ml of 1.5mol / L sodium hydroxide solution was added, and the mixture was stirred for 30min. After filtration, the product was collected, washed with anhydrous ethanol and deionized water, and then dried under vacuum at 60℃ for 24h.

[0032] Example 2:

[0033] A water-retaining material comprising an epoxidized modified attapulgite and a copolymer of 1-allyl-3-methylimidazolium lysine, acrylic acid, methyl methacrylate, and N,N-methylenebisacrylamide.

[0034] The preparation method of the above-mentioned water-retaining material is as follows:

[0035] 10g of attapulgite was dispersed in 100ml of acetone, 1g of KH560 was added dropwise, the mixture was sonicated for 30min, then heated to reflux and stirred for 5h, filtered, the product was collected and washed with anhydrous ethanol and deionized water, and then dried under vacuum at 60℃ for 24h to obtain epoxidized modified attapulgite.

[0036] Lysine and potassium hydroxide were mixed in a 1:1 molar ratio to prepare an aqueous solution of amino acid salt. The mixture was added dropwise to an equal amount of 1-allyl-3-methylimidazolium chloride. After stirring and reacting at 80°C for 5 hours, the mixture was filtered. The filtrate was distilled under reduced pressure to remove water to obtain a crude product. Ten times the mass of anhydrous ethanol was added to the crude product. After stirring thoroughly, the solid was removed by filtration. The filtrate was then distilled under reduced pressure to obtain 1-allyl-3-methylimidazolium lysine salt.

[0037] Under nitrogen protection, 1g of epoxidized attapulgite was dispersed in 500ml of ethanol, followed by 5g of 1-allyl-3-methylimidazolium lysine salt, 50g of acrylic acid, 50g of methyl methacrylate, 1g of N,N-methylenebisacrylamide, and 0.02g of benzoyl peroxide. The mixture was heated to reflux and reacted for 10h, then returned to room temperature. 500ml of 1.5mol / L sodium hydroxide solution was added, and the mixture was stirred for 30min. After filtration, the product was collected, washed with anhydrous ethanol and deionized water, and then dried under vacuum at 60℃ for 24h.

[0038] Example 3:

[0039] A water-retaining material comprising an epoxidized modified attapulgite and a copolymer of 1-allyl-3-methylimidazolium lysine, acrylic acid, methyl methacrylate, and N,N-methylenebisacrylamide.

[0040] The preparation method of the above-mentioned water-retaining material is as follows:

[0041] 10g of attapulgite was dispersed in 100ml of acetone, 1g of KH560 was added dropwise, the mixture was sonicated for 30min, then heated to reflux and stirred for 5h, filtered, the product was collected and washed with anhydrous ethanol and deionized water, and then dried under vacuum at 60℃ for 24h to obtain epoxidized modified attapulgite.

[0042] Lysine and potassium hydroxide were mixed in a 1:1 molar ratio to prepare an aqueous solution of amino acid salt. The mixture was added dropwise to an equal amount of 1-allyl-3-methylimidazolium chloride. After stirring and reacting at 80°C for 5 hours, the mixture was filtered. The filtrate was distilled under reduced pressure to remove water to obtain a crude product. Ten times the mass of anhydrous ethanol was added to the crude product. After stirring thoroughly, the solid was removed by filtration. The filtrate was then distilled under reduced pressure to obtain 1-allyl-3-methylimidazolium lysine salt.

[0043] Under nitrogen protection, 1g of epoxidized attapulgite was dispersed in 500ml of ethanol, followed by 5g of 1-allyl-3-methylimidazolium lysine salt, 40g of acrylic acid, 40g of methyl methacrylate, 0.5g of N,N-methylenebisacrylamide, and 0.02g of benzoyl peroxide. The mixture was heated to reflux and reacted for 10h, then returned to room temperature. 500ml of 1.5mol / L sodium hydroxide solution was added, and the mixture was stirred for 30min. After filtration, the product was collected, washed with anhydrous ethanol and deionized water, and then dried under vacuum at 60℃ for 24h.

[0044] Example 4:

[0045] It is basically the same as Example 1, except that lysine is replaced with glycine.

[0046] Example 5:

[0047] It is basically the same as Example 1, except that lysine is replaced with aspartic acid.

[0048] Comparative Example 1:

[0049] It is basically the same as Example 1, except that 1-allyl-3-methylimidazolium lysine salt is not added.

[0050] Comparative Example 2:

[0051] It is basically the same as Example 1, except that 1-allyl-3-methylimidazolium chloride is used instead of 1-allyl-3-methylimidazolium lysine salt.

[0052] Comparative Example 3:

[0053] It is basically the same as Example 1, except that epoxidized modified attapulgite is not added.

[0054] Comparative Example 4:

[0055] It is basically the same as Example 1, except that attapulgite is added directly, that is, without epoxidation modification.

[0056] Performance testing:

[0057] The water-retaining materials prepared in Examples 1-5 and Comparative Examples 1-4 were used as samples for performance testing.

[0058] ① At room temperature, take a fixed amount of sample in a beaker, add enough water to soak until it becomes a semi-gel, filter out the free water with a sieve, let it stand for 30 minutes, and then weigh it. The formula for calculating the water absorption ratio is as follows:

[0059]

[0060] Where M1 is the mass of the sample after water absorption, and M0 is the initial mass of the sample.

[0061] The test results are shown in Table 1 below:

[0062] Table 1:

[0063]

[0064] As shown in Table 1 above, the water-retaining material prepared by the present invention has a strong water absorption capacity, with a water absorption ratio of more than 700 times.

[0065] ② Mix the water-absorbing sample with dried fine sand at a mass ratio of 1:499, place the mixture in a beaker, and allow it to air dry naturally at room temperature (27℃) and humidity (68%) to release water. Weigh the sample every 10 days and calculate the water retention rate. The formula for calculating the water retention rate is as follows:

[0066]

[0067] Where N1 is the total mass of the sample and fine sand after water absorption, M0 is the total mass of the dried sample and fine sand, and M' is the mass during the natural air-drying and water release process.

[0068] The test results are shown in Table 2 below:

[0069] Table 2:

[0070]

[0071] As shown in Table 2 above, the water-retaining material prepared by the present invention has a strong water retention capacity in soil.

[0072] The above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A water-retaining material, characterized in that, Includes inorganic and organic components; The organic component is obtained by copolymerization of ionic liquid, acrylic monomer and N,N-methylenebisacrylamide; The inorganic component is attapulgite. The attapulgite clay has undergone epoxidation modification treatment; The ionic liquid is an allyl imidazole amino acid salt ionic liquid; The preparation method of the above-mentioned water-retaining material is as follows: Under nitrogen protection, inorganic components are dispersed in an organic solvent, and then ionic liquid, acrylic monomers, N,N-methylenebisacrylamide and free radical initiator are added. The mixture is heated to reflux for 5-15 hours and then restored to room temperature. Sodium hydroxide solution is added, the mixture is stirred and filtered, the product is collected, washed and dried to obtain a water-retaining material. The free radical initiator is any one or a combination of cyclohexanone peroxide, benzoyl peroxide, tert-butyl hydroperoxide, azobisisobutyronitrile, and azobisisoheptanenitrile.

2. The water-retaining material as described in claim 1, characterized in that, The allyl imidazole amino acid salt ionic liquid is any one or a combination of 1-allyl-3-methylimidazolium glycine salt, 1-allyl-3-methylimidazolium glutamate salt, 1-allyl-3-methylimidazolium valine salt, 1-allyl-3-methylimidazolium serine salt, 1-allyl-3-methylimidazolium lysine salt, 1-allyl-3-methylimidazolium arginine salt, and 1-allyl-3-methylimidazolium aspartate salt.

3. The water-retaining material as described in claim 1, characterized in that, The acrylic monomers include acrylic acid and methyl methacrylate; The mass ratio of acrylic acid to methyl methacrylate is 1-5:1-5.

4. The water-retaining material as described in claim 1, characterized in that, The mass ratio of the inorganic component, ionic liquid, and acrylic monomer is 1:5-10:80-100.

5. A method for vegetation restoration in arid regions, characterized in that, When planting seedlings, the water-retaining material as described in any one of claims 1-4 is mixed with the soil excavated from the planting pit and then used as fill soil for planting the seedlings.

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