Humidifying and moisturizing mulching film material for agriculture and forestry and preparation method thereof
By modifying soy protein isolate and calcium carbonate, combined with acylation and enzymatic reaction, the shortcomings of existing plastic film materials in terms of mechanical strength, water vapor barrier properties and thermal stability are solved, and the preparation of moisture-enhancing and moisturizing plastic film materials for agriculture and forestry with excellent performance is achieved.
Patent Information
- Application Number
- CN202510281578.7
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-03-11
- Publication Date
- 2025-05-30
AI Technical Summary
The existing plastic film materials have shortcomings in mechanical strength, water vapor barrier properties and thermal stability, resulting in limited application effects in the agricultural and forestry field.
Soy protein isolate is modified by acylation reagents, succinyl groups are introduced to improve their thermal stability and electrostatic repulsion, and acyl transfer reaction between protein molecules is catalyzed by glutamine transaminase to achieve covalent crosslinking between protein molecules. At the same time, calcium carbonate is modified using silane coupling agent to improve its compatibility and thermal stability with soy protein isolate.
The mechanical strength, water vapor barrier properties and thermal stability of the plastic film material are significantly improved, making it more suitable for moisturizing and moisturizing applications in the agricultural and forestry field.
Smart Images
Figure BDA0005305866970000131
Abstract
Description
Technical Field
[0001] This application relates to the technical field of preparation of plastic film materials, and more specifically, to a humidity-increasing and moisture-retaining plastic film material for agriculture and forestry and a preparation method thereof. Background Art
[0002] In current agricultural production practices, the application of plastic film materials plays an important role in improving the soil environment and promoting crop growth and development. However, although there are various plastic film materials on the market, they still generally face a series of technical and performance challenges. Especially in the research and development of humidity-increasing and moisture-retaining plastic film materials for agriculture and forestry, the deficiencies of the existing technologies are particularly obvious.
[0003] Many existing plastic film materials have poor mechanical strength, which causes them to be easily damaged during use, not only affecting the service life of the plastic film, but also potentially leading to the deterioration of the soil environment, such as the rapid evaporation of soil moisture and the destruction of soil structure. The water vapor barrier performance is one of the important indicators to measure the performance of plastic film materials. However, many existing plastic film materials are difficult to effectively prevent excessive external water penetration while maintaining soil humidity, which to a certain extent limits their application effects in the fields of agriculture and forestry. In addition, insufficient thermal stability is also a major problem of existing plastic film materials. Under high-temperature conditions, some plastic film materials may degrade or deform, which not only reduces the use performance of the plastic film, but also may cause potential pollution to the soil environment.
[0004] Based on the above statements, this application provides a humidity-increasing and moisture-retaining plastic film material for agriculture and forestry and a preparation method thereof. Summary of the Invention
[0005] To solve the problems raised in the background art, this application provides a humidity-increasing and moisture-retaining plastic film material for agriculture and forestry and a preparation method thereof. The soy protein isolate is modified using an acylating reagent, and the molecular structure and charge distribution are changed by introducing succinyl groups, thereby improving its thermal stability and intermolecular electrostatic repulsion. Subsequently, the acyl transfer reaction between protein molecules is catalyzed by transglutaminase to achieve covalent cross-linking between protein molecules, further enhancing its structural stability and functionality. This modification method not only improves the mechanical strength and water vapor barrier performance of the soy protein isolate, but also makes it more compatible with other components. To further improve the performance of the plastic film material, the present invention also introduces modified calcium carbonate as an inorganic filler. By modifying calcium carbonate with a silane coupling agent, it can be tightly combined with organic components such as soy protein isolate, thereby improving the compatibility between the components in the matrix. The modified calcium carbonate not only enhances the mechanical strength and hardness of the plastic film material, but also slows down the decomposition and degradation rate of the soy protein isolate at high temperatures through its thermal stabilizing effect.
[0006] The present application provides a humidifying and moisture-retaining film material for agriculture and forestry and a preparation method thereof, adopting the following technical solutions:
[0007] A preparation method of a humidifying and moisture-retaining film material for agriculture and forestry, comprising the following preparation steps:
[0008] S1. Acylate soy protein isolate with an acylating reagent to obtain acylated soy protein isolate; subsequently, treat the acylated soy protein isolate with transglutaminase to obtain a modified protein;
[0009] S2. Modify calcium carbonate powder with a silane coupling agent to obtain modified calcium carbonate;
[0010] S3. Stir and mix the modified protein obtained in step S1, the modified calcium carbonate obtained in step S2, PBAT, a light stabilizer, a plasticizer, an antioxidant, and a lubricant at room temperature, then transfer them to a twin-screw extruder, melt-blend at 140-180 °C and then extrude and pelletize. After cooling to room temperature, put them into a single-screw blown film machine and blow film at 150-180 °C to obtain the humidifying and moisture-retaining film material for agriculture and forestry.
[0011] Further, in step S1, the modified protein is specifically prepared by the following steps:
[0012] S11. Add soy protein isolate to deionized water, raise the system temperature to 50-60 °C, stir for 10-15 minutes, then add an acylating reagent and adjust the system pH value to 9-10, continue to react for 1-3 hours, then adjust the system pH value to neutral, and dialyze to obtain acylated soy protein isolate;
[0013] S12. Add transglutaminase to the acylated soy protein isolate obtained in step S11, stir and mix, then raise the system temperature to 50-60 °C, treat for 30-60 minutes, then raise the system temperature to 90 °C, treat for 10-15 minutes, and then freeze-dry to obtain the modified protein.
[0014] Further, in step S1, the modified protein is specifically prepared by the following steps:
[0015] S11. Add soy protein isolate to deionized water according to a mass-volume ratio of 1 g:5-10 mL, raise the system temperature to 50-60 °C, stir at a rate of 30-90 rpm for 10-15 minutes, then add an acylating reagent and use a NaOH solution to adjust the system pH value to 9-10, continue to react for 1-3 hours, then use an HCl solution to adjust the system pH value to neutral, and dialyze at 0-4 °C for 48 hours to obtain acylated soy protein isolate;
[0016] S12. Add transglutaminase to the acylated soy protein isolate obtained in step S11, stir and mix, then raise the temperature of the system to 50 - 60 °C. After treating for 30 - 60 minutes, raise the temperature of the system to 90 °C. After treating for 10 - 15 minutes, perform freeze-drying to obtain the modified protein.
[0017] In the above reaction process, the soy protein isolate is modified using an acylating reagent. Through the nucleophilic substitution reaction between the acylating reagent and the amino group in the protein molecule, the acylated soy protein isolate is prepared. Subsequently, transglutaminase is added to the system of the acylated soy protein isolate. After the enzymatic reaction, the enzyme is inactivated and dried to prepare the modified protein.
[0018] Further, in step S11, the acylating reagent used is succinamide.
[0019] Further, the usage ratio of soy protein isolate, acylating reagent, and transglutaminase is 1 g : (0.1 - 0.2) g : (10 - 20) U.
[0020] Further, in step S2, the modified calcium carbonate is specifically prepared by the following steps:
[0021] Dry the calcium carbonate powder for 10 - 30 minutes, then add it to ethyl acetate. After adding a silane coupling agent, perform ultrasonic treatment on the system at room temperature. After the ultrasonic treatment is completed, treat the system at 70 - 80 °C for 1 - 2 hours, filter, wash the product, and dry the product to obtain the modified calcium carbonate.
[0022] Further, in step S2, the modified calcium carbonate is specifically prepared by the following steps:
[0023] Dry the calcium carbonate powder at 80 - 100 °C for 10 - 30 minutes, then add it to ethyl acetate according to the mass - volume ratio of 1 g : (10 - 20) mL. After adding a silane coupling agent, perform ultrasonic treatment on the system at room temperature. After the ultrasonic treatment is completed, treat the system at 70 - 80 °C for 1 - 2 hours, filter, wash the product with absolute ethanol, and dry the product at 50 - 80 °C to obtain the modified calcium carbonate.
[0024] Preferably, the ultrasonic treatment time is 10 - 20 minutes and the ultrasonic frequency is 20 - 22 KHz.
[0025] In the above reaction process, the calcium carbonate powder is modified using a silane coupling agent. Through the hydrolysis and condensation process of the silane coupling agent, Si - O - Ca bonds are formed. During the process, the silane coupling agent introduces hydrophobic organic groups to the surface of the calcium carbonate powder to prepare the modified calcium carbonate. These hydrophobic groups can significantly reduce the surface energy of the metal oxide powder, making it exhibit hydrophobic properties.
[0026] Furthermore, the usage amount ratio of calcium carbonate powder to silane coupling agent is 1:(0.01 - 0.2).
[0027] Preferably, the silane coupling agent is at least one of KH550, KH560, and KH570.
[0028] Furthermore, in step S3, the mass ratio of the modified protein, modified calcium carbonate, PBAT, light stabilizer, plasticizer, antioxidant, and lubricant is (10 - 20):(5 - 10):(70 - 80):(0.1 - 0.5):(2 - 4):(0.5 - 1):(0.5 - 1).
[0029] In summary, the present application has the following beneficial effects:
[0030] 1. In the technical solution of the present invention, an acylating reagent is used to modify soy protein isolate. By using the nucleophilic substitution reaction between the acylating reagent and the amino group in the protein molecule, the acylated soy protein isolate is prepared. Subsequently, transglutaminase is added to the acylated soy protein isolate system. After the enzymatic reaction, the enzyme is inactivated and dried to obtain the modified protein. After modification, succinyl groups are introduced onto the protein, the surface negative charge of the protein increases, the intermolecular electrostatic repulsion increases, and the thermal stability increases. Transglutaminase can catalyze the acyl transfer reaction between protein molecules, resulting in covalent cross-linking between protein molecules. This cross-linking effect can further enhance the structural stability and functionality of soy protein isolate, and improve the mechanical strength and water vapor barrier performance of the film material. In addition, during the modification of soy protein isolate, acylation modification is carried out first and then enzymatic treatment modification. Acylation treatment can introduce new functional groups, while enzymatic treatment can further optimize the molecular structure and properties of soy protein isolate. And acylation treatment can change the molecular structure and charge distribution of soy protein isolate, making it more likely to react with transglutaminase. The combination of the two can significantly improve the functionality and application value of soy protein isolate.
[0031] 2. In the technical solution of the present invention, calcium carbonate is modified with a silane coupling agent to prepare modified calcium carbonate, which is used together with the modified protein as components of the mulch film material. As an inorganic filler, calcium carbonate can enhance the mechanical strength and hardness of the mulch film material; the silane coupling agent can act as a bridge to tightly bind calcium carbonate with organic components such as soy protein isolate, thereby improving the compatibility between the components in the matrix. The modified soy protein isolate has good flexibility and water vapor barrier properties, which can make up for the deficiencies of calcium carbonate in these aspects. Moreover, the modified calcium carbonate is tightly bound to the soy protein isolate through the silane coupling agent to form a stable complex. The calcium carbonate in this complex can act as a heat stabilizer to absorb and disperse heat, thereby slowing down the decomposition and degradation rate of soy protein isolate at high temperatures. At the same time, the presence of the silane coupling agent also enhances the thermal stability of this complex, enabling it to maintain a stable structure and performance at higher temperatures. Therefore, the modified calcium carbonate can significantly improve the thermal stability of soy protein isolate, making it more suitable as one of the components of the mulch film material.
[0032] In summary, by modifying soy protein isolate and calcium carbonate and combining the use of other components such as PBAT, light stabilizer, plasticizer, antioxidant, and lubricant, etc., a high-performance humidifying and moisture-retaining mulch film material for agriculture and forestry can be prepared. Detailed implementation manners
[0033] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without making creative efforts belong to the scope of protection of the present invention.
[0034] Those involved in the specific implementation manners of the present application:
[0035] PBAT: Provided by Dongguan Jinshixiang Plastic Raw Material Co., Ltd., with the product number B2000.
[0036] Soy protein isolate: CAS No. 9010-10-0, purity 99%.
[0037] Glutamine transaminase: CAS No. 80146-85-6, brand Sigma-Aldrich.
[0038] Calcium carbonate powder: CAS No. 471-34-1, 1250-mesh white powder.
[0039] Light stabilizer: BASF Chimassorb 944.
[0040] Plasticizer: triethyl citrate, purity 99%.
[0041] Antioxidant: BASF Irganox 1010.
[0042] Lubricant: Degradable lubricant RF-8, provided by Beijing Ruijie Shengyi New Material Technology Co., Ltd.
[0043] Example 1
[0044] A method for preparing a humidifying and moisturizing mulch film material for agriculture and forestry, comprising the following preparation steps:
[0045] S1, using an acylating agent to perform acylation treatment on the soy protein isolate to obtain acylated soy protein isolate; then using transglutaminase to perform enzyme treatment on the acylated soy protein isolate to obtain a modified protein, the specific operation is as follows:
[0046] S11, adding soy protein isolate to deionized water at a mass volume ratio of 1g:5mL, raising the system temperature to 50°C, stirring at 30rpm for 10 minutes, then adding an acylating agent and adjusting the system pH to 9 with a NaOH solution, continuing the reaction for 1 hour, then adjusting the system pH to neutral with an HCl solution, dialyzing at 0°C for 48 hours to obtain an acylated soy protein isolate; wherein the acylating agent used is succinamide;
[0047] S12, adding glutamine aminotransferase to the acylated soy protein isolate obtained in step S11, stirring and mixing, raising the system temperature to 50°C, treating for 30 minutes, raising the system temperature to 90°C, treating for 10 minutes, and freeze-drying to obtain the modified protein.
[0048] The usage ratio of soy protein isolate, acylation agent and glutamine transaminase is 1g:0.1g:10U.
[0049] S2. Modifying calcium carbonate powder using a silane coupling agent to obtain modified calcium carbonate. The specific operation is as follows:
[0050] The calcium carbonate powder was dried at 80°C for 10 minutes, and then added to ethyl acetate at a mass volume ratio of 1g:10mL. After adding the silane coupling agent, the system was ultrasonically treated at room temperature for 10 minutes at an ultrasonic frequency of 20KHz. After the ultrasonic treatment, the system was treated at 70°C for 1 hour, filtered, and the product was washed with anhydrous ethanol, and dried at 50°C to obtain modified calcium carbonate. The amount of calcium carbonate powder and silane coupling agent used was 1:0.01, and the silane coupling agent used was KH550.
[0051] S3. Mix the modified protein obtained in step S1, the modified calcium carbonate obtained in step S2, PBAT, light stabilizer, plasticizer, antioxidant and lubricant under room temperature conditions, then transfer them to a twin-screw extruder, melt-blend at 140 °C and then extrude and pelletize. After cooling to room temperature, put them into a single-screw blown film machine and blow film at 150 °C to obtain the moisture-increasing and moisture-preserving film material for agriculture and forestry. Among them, the mass ratio of the modified protein, modified calcium carbonate, PBAT, light stabilizer, plasticizer, antioxidant and lubricant is 10:5:70:0.1:2:0.5:0.5.
[0052] Example 2
[0053] A preparation method of a moisture-increasing and moisture-preserving film material for agriculture and forestry, comprising the following preparation steps:
[0054] S1. Acylate soy protein isolate with an acylating reagent to obtain acylated soy protein isolate; then use transglutaminase to enzymatically treat the acylated soy protein isolate to obtain a modified protein. The specific operation is as follows:
[0055] S11. Add soy protein isolate to deionized water according to a mass-to-volume ratio of 1 g:8 mL, raise the system temperature to 55 °C, stir at a rate of 60 rpm for 13 minutes, then add the acylating reagent and use NaOH solution to adjust the system pH value to 9.5, continue to react for 2 hours, then use HCl solution to adjust the system pH value to neutral, and dialyze at 0 °C for 48 hours to obtain acylated soy protein isolate. Among them, the acylating reagent used is succinamide;
[0056] S12. Add transglutaminase to the acylated soy protein isolate obtained in step S11, stir and mix, then raise the system temperature to 55 °C, treat for 45 minutes, then raise the system temperature to 90 °C, treat for 10 minutes, and then freeze-dry to obtain the modified protein.
[0057] Among them, the usage ratio of soy protein isolate, acylating reagent and transglutaminase is 1 g:0.15 g:15 U.
[0058] S2. Modify calcium carbonate powder with a silane coupling agent to obtain modified calcium carbonate. The specific operation is as follows:
[0059] The calcium carbonate powder was dried at 90 °C for 20 minutes, and then added to ethyl acetate according to a mass-volume ratio of 1 g:15 mL. After adding the silane coupling agent, the system was ultrasonically treated at room temperature for 15 minutes with an ultrasonic frequency of 20 KHz. After the ultrasonic treatment, the system was treated at 75 °C for 1 hour, filtered, the product was washed with absolute ethanol, and the product was dried at 65 °C to obtain modified calcium carbonate. Among them, the usage ratio of the calcium carbonate powder to the silane coupling agent was 1:0.1, and the silane coupling agent used was KH550.
[0060] S3. The modified protein obtained in step S1, the modified calcium carbonate obtained in step S2, PBAT, a light stabilizer, a plasticizer, an antioxidant, and a lubricant were stirred and mixed at room temperature, and then transferred to a twin-screw extruder, melt-blended at 160 °C and then extruded into pellets. After cooling to room temperature, it was put into a single-screw blown film machine and blown into a film at 165 °C to obtain the moisture-increasing and moisture-preserving film material for agriculture and forestry. Among them, the mass ratio of the modified protein, the modified calcium carbonate, PBAT, the light stabilizer, the plasticizer, the antioxidant, and the lubricant was 15:8:75:0.3:3:0.7:0.7.
[0061] Example 3
[0062] A preparation method of a moisture-increasing and moisture-preserving film material for agriculture and forestry includes the following preparation steps:
[0063] S1. The soy protein isolate was acylated with an acylating reagent to obtain acylated soy protein isolate; then the acylated soy protein isolate was enzymatically treated with transglutaminase to obtain a modified protein. The specific operation was as follows:
[0064] S11. The soy protein isolate was added to deionized water according to a mass-volume ratio of 1 g:10 mL, the temperature of the system was raised to 60 °C, and it was stirred at a rate of 90 rpm for 15 minutes. Then the acylating reagent was added and the pH value of the system was adjusted to 10 with an NaOH solution, and the reaction continued for 3 hours. Then the pH value of the system was adjusted to neutral with an HCl solution and dialyzed at 4 °C for 48 hours to obtain acylated soy protein isolate. Among them, the acylating reagent used was succinamide.
[0065] S12. Transglutaminase was added to the acylated soy protein isolate obtained in step S11, stirred and mixed, then the temperature of the system was raised to 60 °C, after treatment for 60 minutes, the temperature of the system was raised to 90 °C, after treatment for 15 minutes, it was freeze-dried to obtain the modified protein.
[0066] Among them, the usage ratio of the soy protein isolate, the acylating reagent, and transglutaminase was 1 g:0.2 g:20 U.
[0067] S2. Modify calcium carbonate powder with a silane coupling agent to obtain modified calcium carbonate. The specific operation is as follows:
[0068] Dry the calcium carbonate powder at 100 °C for 30 minutes, then add it to ethyl acetate according to a mass-to-volume ratio of 1 g:20 mL. After adding the silane coupling agent, ultrasonically treat the system at room temperature for 20 minutes with an ultrasonic frequency of 22 KHz. After ultrasonic treatment, treat the system at 80 °C for 2 hours, filter, wash the product with absolute ethanol, and dry the product at 80 °C to obtain the modified calcium carbonate. Among them, the usage ratio of calcium carbonate powder to silane coupling agent is 1:0.2, and the silane coupling agent used is KH560.
[0069] S3. Stir and mix the modified protein obtained in step S1, the modified calcium carbonate obtained in step S2, PBAT, light stabilizer, plasticizer, antioxidant, and lubricant at room temperature, then transfer them to a twin-screw extruder, melt and blend them at 180 °C and then extrude and pelletize. After cooling to room temperature, put them into a single-screw blown film machine and blow film at 180 °C to obtain the agricultural and forestry humidification and moisture-retaining film material. Among them, the mass ratio of modified protein, modified calcium carbonate, PBAT, light stabilizer, plasticizer, antioxidant, and lubricant is 20:10:80:0.5:4:1:1.
[0070] Comparative Example 1
[0071] The difference between this comparative example and Example 1 is that in step S11, this comparative example uses acetic anhydride instead of succinic anhydride.
[0072] Comparative Example 2
[0073] The difference between this comparative example and Example 1 is that in this comparative example, acylated soy protein isolate is used instead of the modified protein. Specifically:
[0074] S1. Acylate soy protein isolate with an acylating reagent to obtain modified protein. The specific operation is as follows:
[0075] Add soy protein isolate to deionized water according to a mass-to-volume ratio of 1 g:5 mL, raise the temperature of the system to 50 °C, stir at a rate of 30 rpm for 10 minutes, then add the acylating reagent and use NaOH solution to adjust the pH value of the system to 9, continue to react for 1 hour, then use HCl solution to adjust the pH value of the system to neutral, and dialyze at 0 °C for 48 hours to obtain the modified protein. Among them, the acylating reagent used is succinamide, and the usage ratio of soy protein isolate to acylating reagent is 1 g:0.1 g.
[0076] The remaining steps are the same as those in Example 1.
[0077] Comparative Example 3
[0078] The difference between this comparative example and Example 1 is that in this comparative example, enzymatically treated soy protein isolate is used instead of the modified protein. Specifically:
[0079] S1. Use transglutaminase to enzymatically treat soy protein isolate to obtain modified protein. The specific operation is as follows:
[0080] Add transglutaminase to soy protein isolate, stir and mix, then raise the system temperature to 50 °C. After treating for 30 minutes, raise the system temperature to 90 °C. After treating for 10 minutes, freeze-dry to obtain the modified protein. Among them, the usage ratio of soy protein isolate to transglutaminase is 1 g:10 U.
[0081] The remaining steps are the same as those in Example 1.
[0082] Comparative Example 4
[0083] The difference between this comparative example and Example 1 is that the modified protein in this comparative example is prepared through the following steps:
[0084] S11. Add transglutaminase to soy protein isolate, stir and mix, then raise the system temperature to 50 °C. After treating for 30 minutes, raise the system temperature to 90 °C. After treating for 10 minutes, freeze-dry to obtain the treated soy protein isolate.
[0085] S12. Add the treated soy protein isolate to deionized water at a mass-to-volume ratio of 1 g:5 mL, raise the system temperature to 50 °C, stir at a rate of 30 rpm for 10 minutes, then add an acylation reagent and use an NaOH solution to adjust the system pH value to 9. Continue to react for 1 hour, then use an HCl solution to adjust the system pH value to neutral, dialyze at 0 °C for 48 hours, and then freeze-dry to obtain the modified protein. Among them, the acylation reagent used is succinamide. The usage ratio of soy protein isolate, transglutaminase, and acylation reagent is 1 g:10 U:0.1 g.
[0086] The remaining steps are the same as those in Example 1.
[0087] Comparative Example 5
[0088] The difference between this comparative example and Example 1 is that in step S2, this comparative example uses calcium carbonate powder (1250-mesh white powder) instead of modified calcium carbonate.
[0089] Performance Test
[0090] The film materials prepared in Examples 1-3 and Comparative Examples 1-5 of this application were made into samples with a specification of 20*20*10 cm. Refer to GB / T 1037-1988 to test the water vapor transmission rate of the material within 24 hours, and refer to GB / T 1040.3-2006 to test the tensile strength and elongation at break. The specific performance test results are shown in Table 1 below:
[0091] Table 1
[0092]
[0093] As can be seen from the results shown in Table 1 above: The product prepared in Example 1 has the best mechanical properties and water vapor barrier effect. From the results in Comparative Example 1, it can be seen that using different types of acylating reagents to modify proteins has different modification effects on soy protein isolate. From the results in Comparative Examples 2 and 3, it can be seen that modifying soy protein isolate can improve the hydrophobic effect of the protein, improve the compatibility of the protein component with the system, and inhibit the permeation of water. From the results in Comparative Example 4, it can be seen that acylating soy protein isolate first will open the structure of the protein and promote the reaction of the protein molecule with transglutaminase. From the results in Comparative Example 5, it can be seen that using a silane coupling agent to modify calcium carbonate powder can improve its dispersion effect in the system and further improve the thermal stability of the protein component.
[0094] In the description of the specification, the description referring to terms such as "one embodiment", "example", "specific example", etc. means that the specific features, structures, materials or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.
[0095] The above content is only an example and explanation of the present invention. Those skilled in the art of this technology can make various modifications or supplements to the described specific embodiments or use similar methods to replace them. As long as they do not deviate from the invention or exceed the scope defined by this claim book, they should belong to the protection scope of the present invention.
Claims
1. A method for preparing a humidifying and moisturizing mulch film material for agriculture and forestry, characterized in that: The method comprises the following preparation steps: S1, using an acylating agent to perform acylation treatment on the soy protein isolate to obtain acylated soy protein isolate; then using transglutaminase to perform enzyme treatment on the acylated soy protein isolate to obtain a modified protein; S2, using a silane coupling agent to modify the calcium carbonate powder to obtain modified calcium carbonate; S3. The modified protein obtained in step S1, the modified calcium carbonate obtained in step S2, PBAT, light stabilizer, plasticizer, antioxidant and lubricant are stirred and mixed at room temperature, and then transferred to a twin-screw extruder, melt-blended at 140-180° C. and extruded into granules, cooled to room temperature, and then put into a single-screw film blowing machine for film blowing at 150-180° C. to obtain a humidifying and moisturizing mulch film material for agriculture and forestry.
2. The method for preparing a humidifying and moisturizing mulch film material for agriculture and forestry according to claim 1, characterized in that: In step S1, the modified protein is specifically prepared by the following steps: S11, adding soy protein isolate to deionized water, raising the system temperature to 50-60° C., stirring for 10-15 minutes, then adding an acylation agent and adjusting the system pH to 9-10, continuing the reaction for 1-3 hours, then adjusting the system pH to neutral, dialyzing, and obtaining acylated soy protein isolate; S12, adding glutamine aminotransferase to the acylated soy protein isolate obtained in step S11, stirring and mixing, raising the system temperature to 50-60°C, treating for 30-60 minutes, raising the system temperature to 90°C, treating for 10-15 minutes, and freeze-drying to obtain the modified protein.
3. The method for preparing a humidifying and moisturizing mulch film material for agriculture and forestry according to claim 2, characterized in that: In step S11, the acylating agent used is succinamide.
4. The method for preparing a humidifying and moisturizing mulch film material for agriculture and forestry according to claim 2, characterized in that: The usage ratio of soy protein isolate, acylating agent and glutamine transaminase is 1g:(0.1-0.2)g:(10-20)U.
5. The method for preparing a humidifying and moisturizing mulch film material for agriculture and forestry according to claim 1, characterized in that: In step S2, the modified calcium carbonate is specifically prepared by the following steps: The calcium carbonate powder is dried for 10-30 minutes, then added to ethyl acetate, and after adding a silane coupling agent, the system is subjected to ultrasonic treatment at room temperature; after the ultrasonic treatment, the system is treated at 70-80° C. for 1-2 hours, filtered, washed, and dried to obtain modified calcium carbonate.
6. The method for preparing a humidifying and retaining moisture mulch material for agriculture and forestry according to claim 5, characterized in that: The ultrasonic treatment time is 10-20 minutes, and the ultrasonic frequency is 20-22 KHz.
7. The method for preparing a humidifying and moisturizing mulch film material for agriculture and forestry according to claim 5, characterized in that: The usage ratio of calcium carbonate powder to silane coupling agent is 1:(0.01-0.2).
8. The method for preparing a humidifying and retaining moisture mulch material for agriculture and forestry according to claim 5, characterized in that: The silane coupling agent is at least one of KH550, KH560 and KH570.
9. The method for preparing a humidifying and retaining moisture mulch material for agriculture and forestry according to claim 1, characterized in that: In step S3, the mass ratio of modified protein, modified calcium carbonate, PBAT, light stabilizer, plasticizer, antioxidant and lubricant is (10-20):(5-10):(70-80):(0.1-0.5):(2-4):(0.5-1):(0.5-1).
10. A mulch material obtained by the method for preparing a humidifying and retaining moisture mulch material for agriculture and forestry as claimed in any one of claims 1 to 9.