Modified guar gum as well as preparation method and application thereof in sand solidification agent

Abstract

The invention belongs to the field of soil improvement, and particularly relates to modified guar gum as well as a preparation method and application thereof in a sand solidification agent. The preparation method comprises the following steps: mixing guar gum and gluconic acid, and reacting in the presence of a catalyst. The guar gum is modified by using gluconic acid, so that the hydrophilicity and adhesiveness of the guar gum are enhanced, and the overall adhesion performance of the guar gum sand solidification agent is improved. The used raw materials such as gluconic acid and guar gum are green, environment-friendly and low in price; the operation is simple.

Description

Technical Field

[0001] The present invention belongs to the field of soil improvement, and particularly relates to a modified guar gum, a preparation method thereof, and an application thereof in a sand-fixing agent. Background Art

[0002] Wind erosion is a global environmental problem closely related to land degradation in arid and semi-arid regions, posing serious risks to the ecological environment, sustainable development, human survival, and various economic factors. There are mainly two methods for controlling soil erosion, including chemical bonding sand-fixing agents and mechanical reinforcement (such as plant vegetation or using geosynthetics). However, they may also cause certain damage while maintaining the ecological environment. Therefore, there is an urgent need to develop environmentally friendly sand-fixing agents.

[0003] Guar gum, as a natural biopolymer, has been proven to be applicable to the production of sand-fixing agents. Traditional guar gum biopolymer sand-fixing agents mainly contain polyacrylamide, guar gum, surfactants, etc. The bonding mechanism mainly involves hydrogen bonding and electrostatic bonding between guar gum and clay, and the sand-fixing effect is mainly achieved by enhancing the cohesion between particles. However, the conventional bonding performance of guar gum is relatively weak, and the hydrophilic and water-retaining properties are insufficient. In areas with severe soil desertification, the performance needs to be improved. Therefore, improving the performance of the main agent of the sand-fixing agent, guar gum, to further enhance the performance of the sand-fixing agent is the key to expanding the application of guar gum sand-fixing agents. Summary of the Invention

[0004] The purpose of the present invention is to overcome the disadvantages in the prior art and provide a modified guar gum, a preparation method thereof, and an application thereof in a sand-fixing agent.

[0005] To achieve the above purpose, the technical solution adopted by the present invention is as follows:

[0006] A preparation method of a modified guar gum, comprising the following steps: reacting guar gum with gluconic acid under a catalyst.

[0007] The catalyst is a mixture of dicyclohexylcarbodiimide and 4-dimethylaminopyridine;

[0008] The mass ratio of the guar gum, dicyclohexylcarbodiimide, and 4-dimethylaminopyridine is 100:

[0009] (28 - 40):1.5.

[0010] The mass ratio of the guar gum to the gluconic acid is 90:(5 - 7).

[0011] Specifically, it comprises the following steps:

[0012] (1) Dissolve a certain amount of guar gum in deionized water and heat with stirring until evenly dispersed; preferably, the ratio of guar gum to deionized water is (1 - 2):100;

[0013] (2) Add gluconic acid to (1) and stir evenly;

[0014] (3) Add a catalyst to (2) for catalysis and stirring. After the reaction ends, add acetone and shake to obtain guar gum gluconate;

[0015] (4) Wash and dry the guar gum gluconate.

[0016] The present invention also includes a modified guar gum obtained by the described preparation method.

[0017] The present invention also includes an application of the described modified guar gum.

[0018] Applied to the preparation of a windbreak and sand fixation agent; the windbreak and sand fixation agent includes the described modified guar gum, an active agent, cationic polyacrylamide, and calcium chloride.

[0019] The active agent is one or a mixture of sodium dodecylbenzenesulfonate, polyvinyl alcohol, and cocamidopropyl betaine.

[0020] The mass ratio of the modified guar gum, cationic polyacrylamide, active agent, and calcium chloride is (4 - 32):(3 - 5):1:5; preferably 8:4:1:5.

[0021] Compared with the prior art, the beneficial effects of the present invention are:

[0022] The present invention uses gluconic acid to modify guar gum, enhancing the hydrophilicity and adhesiveness of guar gum and improving the overall adhesive performance of the guar gum sand fixation agent. The raw materials used, such as gluconic acid and guar gum, are green, environmentally friendly, inexpensive, and the operation is simple. Description of the Drawings

[0023] Figure 1 Shows the mass loss rate after wind erosion cycles of guar gum and guar gum gluconate with different guar gum dosage ratios;

[0024] Figure 2 Shows the water content change curves of guar gum and guar gum gluconate with different guar gum dosage ratios. Detailed Embodiments

[0025] In order to enable those skilled in the art of the present technology to better understand the technical solutions of the present invention, the present invention will be further described in detail below with reference to the drawings and the best embodiments.

[0026] Example 1

[0027] Preparation method of gluconic acid guar gum, comprising the following steps:

[0028] (1) Dissolve 2 g of guar gum (Qingdao Runhuan Technology Engineering Co., Ltd., product number R1513) in 200 ml of deionized water, heat and stir at 50 °C until evenly dispersed;

[0029] (2) Add 0.14 g of gluconic acid to (1) and stir until completely dissolved;

[0030] (3) Add 0.6 g of dicyclohexylcarbodiimide and 0.03 g of 4-dimethylaminopyridine to (2) for catalysis and stir. After the reaction is completed, add acetone and shake slowly to obtain gluconic acid guar gum;

[0031] (4) Wash the gluconic acid guar gum with an ethanol / water mixed solution, and finally wash it again with ethanol and send it to a vacuum oven at 35 °C for drying;

[0032] (5) Add 2 g of gluconic acid guar gum, 1 g of cationic polyacrylamide (Mw ~ 500,000), 0.25 g of sodium dodecylbenzenesulfonate, and 1.25 g of calcium chloride to deionized water in sequence, stir evenly, and the stirring rate is 800 r / min at room temperature.

[0033] Example 2

[0034] The difference between Example 2 and Example 1 is only that the addition amount of gluconic acid guar gum in step (5) is 1 g.

[0035] Example 3

[0036] The difference between Example 3 and Example 1 is only that the addition amount of gluconic acid guar gum in step (5) is 3 g.

[0037] Example 4

[0038] The difference between Example 4 and Example 1 is only that the addition amount of gluconic acid guar gum in step (5) is 4 g.

[0039] Comparative Example 1

[0040] Comparative Example 1 is a sand-fixing agent using ordinary guar gum, which is prepared by the following method: Add 2 g of guar gum, 1 g of cationic polyacrylamide (Mw ~ 500,000), 0.25 g of sodium dodecylbenzenesulfonate, and 1.25 g of quicklime to deionized water in sequence, stir evenly, and the stirring rate is 800 r / min at room temperature.

[0041] Comparative Example 2

[0042] The difference between Comparative Example 2 and Comparative Example 1 is only that the addition amount of gluconic acid guar gum is 3 g.

[0043] Test results

[0044] 1. Wind erosion resistance performance test;

[0045] Gradually increase the wind speed in the order from low to high wind levels (strong wind < fresh gale < strong breeze < gale < violent storm, wind speed range: 10 - 26 m / s), blow parallel to the surface of the sand piles sprayed with sand - fixing and dust - suppressing agents with different solid contents, monitor the real - time wind speed on the surface of the sand piles using an anemometer, maintain a fixed wind speed for 10 minutes, observe the damage caused by different wind levels to the consolidation layer, and calculate the mass loss rate of the sand piles before and after the test to evaluate the wind erosion resistance performance of the sand - fixing and dust - suppressing agents;

[0046] 2. Water retention performance test; Under a constant room temperature of 25 °C, an indoor relative humidity of 27%, and a cool and ventilated environment, simulate natural conditions and let the sand columns with different solid contents of sand - fixing and dust - suppressing agents dry naturally. Weigh them every 5 hours until the sand columns are completely dry, calculate the water content of the sand columns at each moment, and analyze and compare the water retention performance of the sand columns with different solid contents.

[0047] Table 1 is the table of the mass loss rate results after the wind erosion cycle of guar gum and gluconic acid guar gum with different usage ratios of guar gum in different examples and comparative examples; Figure 1 It is the mass loss rate after the wind erosion cycle of guar gum and gluconic acid guar gum with different usage ratios of guar gum;

[0048] Table 1

[0049]

[0050] Table 2 is the table of the water content changes in different examples and comparative examples; Figure 2 It is the water content change curve of guar gum and gluconic acid guar gum with different usage ratios of guar gum.

[0051] Table 2

[0052]

[0053] From Figure 1 and Table 1, it can be seen that the sand - fixing agent prepared by the technical solution of this application has more stable and more effective sand - fixing performance than the conventional plant - gum sand - fixing agent. Even as the wind speed increases, the sand pile loss of Examples 1 - 4 of the modified guar gum sand - fixing agent is still lower than that of Comparative Examples 1 and 2; when the addition amount of the modified guar gum is reduced (such as in Example 3), the sand pile loss increases significantly, indicating that the addition of this modified guar gum plays a key role in improving the sand - fixing performance. From Figure 2As can be seen from Table 2, when the guar gum prepared after modification is added to the sand binder for use, the rate of decrease in the water content of the sand pile is significantly reduced, indicating that this modified guar gum can effectively prevent water evaporation, has a good effect on retaining water in the sand pile, and is conducive to the exertion of the sand fixation effect.

[0054] The above are only the preferred embodiments of the present invention. It should be noted that for those of ordinary skill in the art, without departing from the principle of the present invention, several improvements and refinements can be made, and these improvements and refinements should also be regarded as the protection scope of the present invention.

Claims

1. A preparation method of modified guar gum, characterized in that, It includes the following steps: reacting guar gum and gluconic acid under a catalyst to obtain...

2. The preparation method of the modified guar gum according to claim 1, characterized in that, The catalyst is a mixture of dicyclohexylcarbodiimide and 4-dimethylaminopyridine.

3. The preparation method of the modified guar gum according to claim 2, wherein, The mass ratio of the guar gum, dicyclohexylcarbodiimide, and 4-dimethylaminopyridine is 100:(28 - 40):1.

5.

4. The preparation method of the modified guar gum according to claim 2, wherein, The mass ratio of the guar gum and gluconic acid is 90:(5 - 7).

5. The preparation method of the modified guar gum according to claim 1, characterized in that (1) Dissolve a certain amount of guar gum in deionized water and heat with stirring until evenly dispersed; preferably, the ratio of the guar gum to deionized water is (1 - 2):100; (2) Add gluconic acid to (1) and stir evenly; (3) Add the catalyst to (2) for catalysis and stir. After the reaction, add acetone and shake to obtain gluconic acid guar gum; (4) Wash and dry the gluconic acid guar gum.

6. A modified guar gum obtained by the preparation method according to any one of claims 1 - 5.

7. The application of the modified guar gum according to claim 6.

8. The application according to claim 7, characterized in that, It is applied to the preparation of a windbreak and sand fixation agent; preferably, the windbreak and sand fixation agent includes the modified guar gum according to claim 6, an active agent, cationic polyacrylamide, and calcium chloride.

9. The application according to claim 8, wherein The active agent is one or a mixture of sodium dodecylbenzenesulfonate, polyvinyl alcohol, and cocamidopropyl betaine.

10. The application according to claim 8, characterized in that, The mass ratio of the modified guar gum, cationic polyacrylamide, active agent, and calcium chloride is (4 - 32):(3 - 5):1:5; preferably 8:4:1:5.

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