Modified polyaspartic acid dust suppressant as well as preparation method and application thereof
The preparation of modified polyaspartic acid dust suppressant solves the problems of water waste, soil salinity accumulation and environmental pollution caused by existing dust suppressants. It achieves environmentally friendly and effective dust suppression and soil water retention performance, and is harmless to plants.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2026-01-09
- Publication Date
- 2026-04-14
AI Technical Summary
Existing dust suppressants have problems such as water waste, soil salinity accumulation, high production costs, and environmental pollution during use, especially being harmful to soil and plants.
Modified polyaspartic acid dust suppressant was prepared by modifying polyaspartic acid with glycidyl methacrylate under weakly acidic conditions. The modified polyaspartic acid dust suppressant was sprayed or diluted and then sprayed onto the soil surface to form a stable cementing layer to suppress dust.
Modified polyaspartic acid dust suppressant is biodegradable, does not pollute the environment, maintains soil ecology, has good dust suppression and water retention properties, is harmless to plants, and is inexpensive.
Smart Images
Figure CN121851379A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of environmental protection technology, and more specifically to a modified polyaspartic acid dust suppressant, its preparation method, and its application. Background Technology
[0002] Dust pollution is an environmental problem that cannot be ignored in China's industrialization and urbanization process, especially in industries such as mining, construction, road construction, and agriculture, where dust pollution is particularly severe. Dust not only affects air quality but also causes various harms to human health, the ecological environment, and equipment and facilities. The use of dust suppressants can effectively improve the generation and dispersion of dust.
[0003] Currently, dust suppressants are mainly classified into water-based dust suppressants, inorganic chemical dust suppressants, organic dust suppressants, and composite dust suppressants. Water-based dust suppressants are usually composed of water and some chemical components (such as surfactants, coagulants, etc.). They suppress dust from soil and ore surfaces by spraying water mist or combining water with chemical components to form a film. This type of dust suppressant requires a large amount of water resources, and its use may lead to water waste, especially in arid areas or water-scarce regions.
[0004] Inorganic chemical dust suppressants use inorganic salts such as sodium chloride, calcium chloride, aluminum sulfate, and lime as their main components. They change the surface tension of the soil, form a stable soil surface layer, and reduce dust generation. However, long-term use of inorganic salt dust suppressants may lead to soil salt accumulation, which in turn affects soil permeability and plant growth.
[0005] Organic dust suppressants, such as ethylene glycol and polyvinyl alcohol, combine with soil particles to form a film or cementitious layer. However, these polymers are difficult to completely degrade, and long-term use may have an impact on the ecological environment. Composite dust suppressants combine multiple components (such as water-based, chemical, and organic components) to form a more comprehensive dust suppression product. However, due to the large number of components in composite dust suppressants, the production process is relatively complex, which may lead to higher production costs.
[0006] Therefore, how to provide an environmentally friendly soil dust suppressant made from polyaspartic acid and its preparation method is a technical problem that urgently needs to be solved in this field. Summary of the Invention
[0007] In view of this, the present invention provides a low-cost, effective, environmentally friendly, and harmless modified polyaspartic acid dust suppressant, its preparation method, and its application.
[0008] To achieve the above objectives, the present invention adopts the following technical solution: A modified polyaspartic acid dust suppressant, wherein the dust suppressant is obtained by modifying polyaspartic acid with glycidyl methacrylate under weak acid conditions.
[0009] Preferably, the mass ratio of polyaspartic acid to glycidyl methacrylate is (20-2):1; more preferably, the mass ratio of polyaspartic acid to glycidyl methacrylate is 5:1.
[0010] Preferably, the weak acid condition is achieved by adjusting the pH to 4-6.
[0011] More preferably, the weak acid condition is to adjust the pH to 4.5-5.5.
[0012] Another object of the present invention is to provide a method for preparing a modified polyaspartic acid dust suppressant, comprising the following steps: The pH of the polyaspartic acid aqueous solution was adjusted to a weakly acidic condition using hydrochloric acid solution. Then, glycidyl methacrylate was added, and the mixture was reacted at a certain temperature for a period of time to obtain a modified polyaspartic acid solution. After drying, the modified polyaspartic acid powder was obtained, which is the modified polyaspartic acid dust suppressant.
[0013] Preferably, the concentration of the hydrochloric acid solution is 6 mol / L.
[0014] Preferably, the preparation method of the polyaspartic acid aqueous solution is as follows: the aspartic acid raw material is subjected to dehydration condensation reaction to obtain the intermediate product polysuccinimide; the polysuccinimide is hydrolyzed in NaOH solution to obtain the polyaspartic acid aqueous solution.
[0015] Preferably, the temperature of the dehydration polycondensation reaction is 180-220°C, and more preferably, it is 200°C.
[0016] Preferably, the concentration of the NaOH solution is 1-3 mol / L, more preferably 2 mol / L.
[0017] Preferably, the mass ratio of the polysuccinimide to the NaOH solution is 1:4-12, and more preferably, it is 1:6.
[0018] Preferably, the reaction time at a certain temperature is 5-12 h at 50°C, and more preferably, it is 7-10 h.
[0019] Preferably, the drying is performed using a spray dryer.
[0020] Another object of the present invention is to provide the application of modified polyaspartic acid dust suppressant in soil improvement.
[0021] In this invention, the modified PASP dust suppressant is applied in two forms: (1) the dry modified PASP powder is directly sprayed onto the soil surface to absorb moisture from the air and accelerate the dust suppression effect; (2) After diluting the modified PASP powder with water at a certain ratio (usually 1:100), spray it on the soil surface.
[0022] As can be seen from the above technical solution, compared with the prior art, the present invention has the following technical effects: 1. Polyaspartic acid is a polymer material derived from natural amino acids and possesses excellent biodegradability. When used as a dust suppressant, polyaspartic acid can be transformed into harmless substances in the natural environment through microbial decomposition or other natural processes. This characteristic ensures that polyaspartic acid dust suppressants will not cause persistent pollution to soil, water bodies, or other environmentally friendly substances after use, making it significantly more environmentally friendly than traditional chemical dust suppressants.
[0023] 2. Traditional dust suppressants may leave harmful residues during use, causing long-term effects on plants and soil. In particular, salt-based dust suppressants can lead to soil salinization after repeated use, thus affecting agricultural production. Polyaspartic acid dust suppressants, however, can rapidly degrade under natural conditions, without negatively impacting agricultural production and maintaining the natural ecological characteristics of the soil, thereby avoiding the aforementioned environmental problems.
[0024] 3. Modified polyaspartic acid dust suppressant, through its unique molecular structure (rich in functional groups such as carboxyl groups and double bonds), can generate a strong affinity with soil particles and mineral surfaces. The combination of this substance with soil particles can not only increase soil moisture, but also form a stable cementing layer under continuous irradiation of sunlight or ultraviolet light, effectively preventing dust from flying. Attached Figure Description
[0025] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. The drawings in this description are merely embodiments of the present invention.
[0026] Figure 1 As a dust suppressant 1 H-NMR spectrum.
[0027] Figure 2 This is a photograph of the actual dust suppressant gel film. Detailed Implementation
[0028] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.
[0029] Example 1 This embodiment provides a method for preparing a modified polyaspartic acid dust suppressant: Aspartic acid was subjected to dehydration condensation at 200℃ to obtain intermediate product PSI. Five parts of PSI were hydrolyzed in 30 parts of 2 mol / L NaOH solution to obtain an aqueous solution of product PASP, with a mass ratio of 1:6. The obtained PASP aqueous solution was adjusted to a weakly acidic condition of pH 5.0 with 6 mol / L hydrochloric acid solution, and one part of glycidyl methacrylate was added. The reaction was carried out at 50℃ for 8 h to obtain a modified PASP solution. The solution was dried by a spray dryer to obtain dry modified PASP powder.
[0030] Example 2 This embodiment provides a method for preparing a modified polyaspartic acid dust suppressant: Aspartic acid was subjected to dehydration condensation at 200℃ to obtain intermediate product PSI. Five parts of PSI were hydrolyzed in 30 parts of 2 mol / L NaOH solution to obtain an aqueous solution of product PASP, with a mass ratio of 1:6. The obtained PASP aqueous solution was adjusted to a weakly acidic condition of pH 5.0 with 6 mol / L hydrochloric acid solution. Two parts of glycidyl methacrylate were added, and the reaction was carried out at 50℃ for 8 h to obtain modified PASP solution. The solution was dried by a spray dryer to obtain dry modified PASP powder.
[0031] Example 3 This embodiment provides a method for preparing a modified polyaspartic acid dust suppressant: Aspartic acid was subjected to dehydration condensation polymerization at 220℃ to obtain intermediate product PSI. 10 parts of PSI were hydrolyzed in 100 parts of 2 mol / L NaOH solution to obtain an aqueous solution of product PASP, with a mass ratio of 1:10. The obtained PASP aqueous solution was adjusted to a weakly acidic condition of pH 4.5 with 6 mol / L hydrochloric acid solution, and 1 part of glycidyl methacrylate was added. The reaction was carried out at 50℃ for 11 h to obtain a modified PASP solution. The solution was dried by a spray dryer to obtain dry modified PASP powder.
[0032] Example 4 This embodiment provides a method for preparing a modified polyaspartic acid dust suppressant: Aspartic acid was subjected to dehydration condensation polymerization at 185℃ to obtain intermediate product PSI. 15 parts of PSI were hydrolyzed in 75 parts of 2 mol / L NaOH solution to obtain an aqueous solution of product PASP, with a mass ratio of 1:5. The obtained PASP aqueous solution was adjusted to a weakly acidic condition of pH 5.5 with 6 mol / L hydrochloric acid solution, and 1 part of glycidyl methacrylate was added. The reaction was carried out at 50℃ for 6 h to obtain a modified PASP solution. The solution was dried by a spray dryer to obtain dry modified PASP powder.
[0033] Example 5 The modified PASP powder from Example 1 was directly sprayed onto the soil surface to absorb moisture from the air and accelerate the dust suppression effect. After the surface layer was formed, a small sample was cut from the surface and its dust suppression performance was measured. To ensure that there would be no systematic impact due to the location within the site, samples were randomly collected from four locations on each soil surface, and the compressive strength and water retention performance were measured and the average values were recorded.
[0034] Example 6 The modified PASP powder from Example 1 was diluted with water at a certain ratio (usually 1:100) and sprayed onto the soil surface. After the surface layer formed, a small sample was cut from the surface, and its dust suppression performance was measured. To ensure that there was no systematic impact due to the location within the site, samples were randomly collected from four locations on each soil surface, and the compressive strength and water retention performance were measured and the average values were recorded.
[0035] Example 7 The modified PASP powder from Example 2 was directly sprayed onto the soil surface to absorb moisture from the air and accelerate the dust suppression effect. After the surface layer was formed, a small sample was cut from the surface and its dust suppression performance was measured. To ensure that there was no systematic impact due to the location within the site, samples were randomly collected from four locations on each soil surface, and the water retention performance was measured and the average value was recorded.
[0036] Example 8 The modified PASP powder from Example 2 was diluted with water at a certain ratio (usually 1:100) and sprayed onto the soil surface. After the surface layer formed, a small sample was cut from the surface, and its dust suppression performance was measured. To ensure that there would be no systematic impact due to location within the site, samples were randomly collected from four locations on each soil surface, and the water retention performance was measured and the average value was recorded.
[0037] Example 9 Sandy soil samples were collected, and the soil moisture content was adjusted to 8%. The samples were then placed in rectangular plots (45 × 35 cm) using a shovel. The modified PASP powder from Example 1 was diluted with water at a certain ratio (usually 1:100) and sprayed onto the soil surface. Fifty Astragalus (A. adsurgen) seeds were then pressed into the soil (2 cm deep), and the soil was kept consistently moist. The seeds were germinated in a well-ventilated room without heating, with controlled ambient temperature and natural indirect light. The air temperature and relative humidity were maintained at 25°C and 28%, respectively.
[0038] Example 10 Sandy soil samples were collected, and the soil moisture content was adjusted to 8%. The samples were then placed in rectangular plots (45 × 35 cm) using a shovel. The modified PASP powder from Example 2 was diluted with water at a certain ratio (usually 1:100) and sprayed onto the soil surface. Fifty Astragalus seeds were then pressed into the soil (2 cm deep), and the soil was kept consistently moist. The seeds were germinated in a well-ventilated room without heating, with controlled ambient temperature and natural indirect light. The air temperature and relative humidity were maintained at 25°C and 28%, respectively.
[0039] Comparative Example 1 Aspartic acid was subjected to dehydration and polycondensation at 200℃ to obtain the intermediate product PSI. Five parts of PSI were hydrolyzed in 30 parts of 2 mol / L NaOH solution to obtain an aqueous solution of PASP product, with a mass ratio of 1:6. The solution was then adjusted to a weakly acidic condition of pH 5.0 with 6 mol / L hydrochloric acid solution to obtain an unmodified PASP solution. The solution was dried by a spray dryer to obtain dry unmodified PASP powder.
[0040] The unmodified PASP powder was diluted with water at a certain ratio (usually 1:100) and sprayed onto the soil surface. After the surface layer formed, a small sample was cut from the surface and its dust suppression performance was measured. To ensure that there was no systematic impact due to location within the site, samples were randomly collected from four locations on each soil surface, and the water retention performance was measured and the average value was recorded.
[0041] Comparative Example 2 Sandy soil samples were collected, and the soil moisture content was adjusted to 8%. The samples were then placed in rectangular plots (45 × 35 cm) using a shovel. Fifty Astragalus seeds were pressed into the soil (2 cm deep), and the soil was kept consistently moist. The seeds were germinated in a well-ventilated room without heating, with controlled ambient temperature and natural indirect light. The air temperature and relative humidity were maintained at 25°C and 28%, respectively.
[0042] Comparative Example 3 Sandy soil samples were collected, and the soil moisture content was adjusted to 8%. The samples were then placed in rectangular plots (45 × 35 cm) using a shovel. Unmodified PASP powder from Comparative Example 1 was diluted with water at a certain ratio (usually 1:100) and sprayed onto the soil surface. Fifty Astragalus seeds were then pressed into the soil (2 cm deep), and the soil was kept consistently moist. The seeds were germinated in a well-ventilated room without heating, with controlled ambient temperature and natural indirect light. The air temperature and relative humidity were maintained at 25°C and 28%, respectively.
[0043] Table 1 Comparison of compressive strength between two dust suppressant application methods
[0044] Soil compressive strength indicates soil compaction; higher compressive strength indicates denser soil and less dust generation. Table 1 shows that the soil compressive strength of dust suppressants applied as a solution is superior to that in powder form. This can be explained by the fact that when modified PASP solution is sprayed, it penetrates into the soil and comes into full contact with soil particles, resulting in strong interaction and better dust suppression. Conversely, when modified PASP is applied as powder, it only contacts surface soil particles, leading to poorer interaction. However, considering its application on arid lands with limited water, the powder method may be more practical, as the polymer can absorb moisture when nighttime air humidity is relatively high.
[0045] Table 2. Effects of dust suppressants on soil water retention capacity
[0046] PASP and its modifiers possess excellent water absorption capacity, thus preventing soil moisture loss and prolonging the dust suppression effect. Therefore, the following experiment was designed to evaluate their water retention capacity when applied to sandy soil. Soil treated with the dust suppressant (250 g, 1.5% of soil weight) was filled into a plastic container (12 cm in diameter, 6 cm deep). Then, 100 g of tap water was added to the container. The container was placed on a table in a room with a constant air temperature (25℃, 20% relative humidity). A soil sample was taken every 24 hours and dried in an oven at 105℃ for 24 hours. The weight loss was measured: Moisture content (%) = (Wet soil weight - Dry soil weight) / Wet soil weight × 100. Table 2 shows the results of soil moisture content (1.5%, based on soil weight) treated with the dust suppressant. It can be seen that within 14 days, the soil moisture content was significantly higher than the control group.
[0047] Table 3 Comparison of seed germination rates between the examples and the comparative examples
[0048] Considering the environmental performance evaluation of dust suppressants, a seed germination experiment was designed to assess the effects of PASP and its modification on plant growth. Astragalus membranaceus was chosen as the model because it can grow in poor soil and is well-resistant to drought and cold. Germination rate is expressed as the percentage of germinated live seeds: Germination rate (%) = Number of germinated seeds / Initial number of seeds × 100%. Table 3 shows that the modified PASP dust suppressant has no toxic effects on plants.
[0049] To verify the modification of the dust suppressant, Example 1 and Comparative Example 1 were tested. 1 For H-NMR testing, the specific procedure is to dissolve one part of the sample in four parts of deionized water, dialyze it in deionized water for 24 h through a 3 kDa dialysis bag, and then freeze-dry it to obtain a high-purity sample for NMR analysis. Figure 1 The results showed that the GMA-modified sample had a double bond structure, which increased the number of active groups compared to the unmodified sample, enabling it to self-crosslink and form a stable cement layer.
[0050] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on its differences from other embodiments. Similar or identical parts between embodiments can be referred to interchangeably. For the apparatus disclosed in the embodiments, since they correspond to the methods disclosed in the embodiments, the description is relatively simple; relevant parts can be referred to the method section.
[0051] The above description of the disclosed embodiments enables those skilled in the art to make or use the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.
Claims
1. A modified polyaspartic acid dust suppressant, characterized by, The dust suppressant is obtained by modifying polyaspartic acid with glycidyl methacrylate under weak acid conditions.
2. The modified polyaspartic acid dust suppressant of claim 1, wherein, The mass ratio of polyaspartic acid to glycidyl methacrylate is (20-2):
1.
3. The modified polyaspartic acid dust suppressant of claim 1, wherein, The weak acid condition is achieved by adjusting the pH to 4-6.
4. The preparation method of the modified polyaspartic acid dust suppressant as described in claim 3, characterized in that, Includes the following steps: The pH of the polyaspartic acid aqueous solution was adjusted to a weakly acidic condition using hydrochloric acid solution. Then, glycidyl methacrylate was added, and the mixture was reacted at a certain temperature for a period of time to obtain a modified polyaspartic acid solution. After drying, the modified polyaspartic acid powder was obtained, which is the modified polyaspartic acid dust suppressant.
5. The method for preparing a modified polyaspartic acid dust suppressant according to claim 4, characterized in that, The preparation method of the polyaspartic acid aqueous solution is as follows: the aspartic acid raw material is subjected to dehydration condensation reaction to obtain the intermediate product polysuccinimide; the polysuccinimide is hydrolyzed in NaOH solution to obtain the polyaspartic acid aqueous solution.
6. The method for preparing a modified polyaspartic acid dust suppressant according to claim 5, characterized in that, The temperature of the dehydration polycondensation reaction is 180-220℃.
7. The method for preparing a modified polyaspartic acid dust suppressant according to claim 6, characterized in that, The concentration of the NaOH solution is 1-3 mol / L.
8. The method for preparing a modified polyaspartic acid dust suppressant according to claim 7, characterized in that, The mass ratio of the polysuccinimide to the NaOH solution is 1:4-12.
9. The method for preparing a modified polyaspartic acid dust suppressant according to claim 8, characterized in that, The reaction time at a certain temperature is 5-12 h at 50℃; The drying process is carried out using a spray dryer.
10. The application of the modified polyaspartic acid dust suppressant according to any one of claims 1-3 or the modified polyaspartic acid dust suppressant prepared by the preparation method according to any one of claims 4-9 in soil improvement.