A method for efficiently preparing a green psyllium gum-ferulic acid adhesive

Abstract

The application discloses a method for efficiently preparing a green psyllium gum-fumaric acid adhesive, and belongs to the technical field of green psyllium gum-fumaric acid adhesive preparation processes. The method uses psyllium gum and fumaric acid as raw materials, can realize efficient and simple grafting reaction, and can realize preparation of the green adhesive after the sugar-fumaric acid complex (5%) prepared by the method is fully dissolved.

Description

Technical Field

[0001] This invention relates to a preparation process of a green adhesive made from psyllium husk and ferulic acid, and particularly to a method for efficiently preparing a green adhesive made from psyllium husk and ferulic acid, belonging to the technical field of preparation process technology for green adhesive made from psyllium husk and ferulic acid. Background Technology

[0002] Psyllium gum, a natural water-soluble dietary fiber extracted from plantain seeds, has a unique chemical composition and excellent properties. It is mainly composed of polysaccharides such as arabinoxylan, galacturonic acid, rhamnose, galactose, and glucose. These polysaccharides endow psyllium gum with good water solubility, allowing it to disperse and dissolve rapidly in water. Simultaneously, it possesses high viscosity, forming a stable colloidal system in solution, a property with important applications in many fields.

[0003] For example, in the food industry, it is often used as a thickener and stabilizer to improve the texture and taste of food and extend its shelf life; in the pharmaceutical field, due to its good biocompatibility, it can be used to prepare sustained-release drug formulations to control the release rate of drugs and improve their efficacy; in the cosmetics industry, it can increase the viscosity of products and improve their stability and user experience.

[0004] Ferulic acid is a natural phenolic acid that is widely found in plant cell walls.

[0005] It not only possesses various biological activities such as antioxidation, anti-inflammation, and antibacterial properties, but also demonstrates unique application value in the field of materials science. The phenolic hydroxyl groups and double bonds in the ferulic acid molecule enable it to participate in a variety of chemical reactions, providing possibilities for its material modification.

[0006] However, there are many problems with the production and use of traditional adhesives.

[0007] On the one hand, many commercially available adhesives are based on synthetic materials, which often require a large amount of fossil energy to produce and generate harmful chemical waste, causing serious pollution to the environment.

[0008] On the other hand, some traditional adhesives also have certain limitations in performance, such as insufficient adhesion, limited bonding range, and poor water resistance, making it difficult to meet the increasingly diverse industrial and daily needs.

[0009] In the field of covalent modification technology of polysaccharides and polyphenols, although some studies have attempted to combine natural polysaccharides and polyphenols to prepare novel materials, existing methods generally suffer from harsh reaction conditions, complex operation, and low reaction efficiency, making it impossible to achieve large-scale industrial production. To address these issues, a method for efficiently preparing psyllium gum-ferulic acid green adhesive was designed. Summary of the Invention

[0010] The main objective of this invention is to provide a method for efficiently preparing psyllium gum-ferulic acid green adhesive.

[0011] The objective of this invention can be achieved by adopting the following technical solution:

[0012] A method for efficiently preparing psyllium husk gum-ferulic acid green adhesive includes the following steps:

[0013] Step 1: Dissolve ferulic acid in N,N-dimethylformamide;

[0014] Step 2: Add an appropriate amount of N,N'-diisopropylcarbodiimide to the dissolved ferulic acid solution, wherein the molar ratio of ferulic acid to DIC is 1:1;

[0015] Step 3: After the solution reaction in Step 2 is complete, add an appropriate amount of 4-dimethylaminopyridine and react for 30 minutes. The molar ratio of ferulic acid to DMAP is 6:5.

[0016] Step 4: Mix the dissolved psyllium gum with the solution obtained in Step 3 and react overnight;

[0017] Step 5: After the reaction is complete, add anhydrous ethanol to terminate the reaction, and wash and filter with anhydrous ethanol.

[0018] Step 6: Dry the powder obtained from washing and filtration at low temperature to obtain the glycophenolic complex;

[0019] Step 7: Dissolve psyllium gum-ferulic acid in deionized water at a mass fraction of 5% wt, stir to dissolve, and you will get psyllium gum-ferulic acid green adhesive.

[0020] Preferably, the dissolution temperature of ferulic acid in N,N-dimethylformamide in step one is 20-30°C;

[0021] The stirring speed is 200-300 r / min, and the dissolution time is 30-60 min.

[0022] Preferably, after adding N,N'-diisopropylcarbodiimide in step two, the reaction temperature is controlled at 25-35℃ and the reaction time is 2-3h.

[0023] Preferably, the concentration of the dissolved psyllium gum in step four is 10-20% wt, and the stirring speed during the mixing reaction is 100-150 r / min.

[0024] Preferably, in step five, the anhydrous ethanol washing is performed 3-5 times, with each washing session lasting 10-15 minutes.

[0025] Preferably, the low-temperature drying temperature in step six is ​​40-60℃, and the drying time is 6-10 hours.

[0026] Preferably, the adhesive has a viscosity of not less than 5000 mPa·s at 25°C and a shear rate of 10 (1 / s).

[0027] Preferably, the adhesive, when subjected to a 180° peel adhesion test, peels at a rate of 10 mm / min over a 60 cm adhesive surface. 2 On the wood chips, the maximum tensile force is not less than 50N, and the tensile time is not less than 30min.

[0028] Beneficial technical effects of the present invention:

[0029] This invention provides a method for efficiently preparing a green adhesive using psyllium husk gum and ferulic acid. The psyllium husk gum is a natural water-soluble dietary fiber extracted from the seeds of plantain, and the ferulic acid is a natural phenolic acid found in the cell walls of plants. The natural source makes the prepared adhesive highly safe and biocompatible, and it can be widely used in fields with high safety requirements, such as food packaging and pharmaceutical product assembly, without causing harm to the human body and the environment.

[0030] The preparation method is simple and efficient, with clear steps and mild reaction conditions. It does not require complex equipment or harsh conditions, thus reducing production costs and technical barriers. For example, in the grafting reaction, common reagents and conventional reaction temperatures and times can be used to complete the covalent grafting of ferulic acid onto psyllium gum in a short time, making it suitable for large-scale industrial production and providing a new feasible method for the covalent modification of polyphenols and polysaccharides.

[0031] The adhesive obtained after dissolving the prepared phenolic complex exhibits excellent performance. Firstly, it has high viscosity, which ensures a tight bond between the adhesive and the adherend in practical applications, forming a strong adhesion that meets the bonding needs of various materials. Secondly, it has a wide bonding range, effectively bonding materials such as wood chips and colored craft paper, making it suitable for a wide range of applications. Thirdly, compared to commercially available children's adhesives, it has less odor, giving it an advantage in odor-sensitive applications. Furthermore, it demonstrates excellent performance in tensile tests, exhibiting superior maximum tensile force and tensile endurance, significantly enhancing the strength and tensile strength of bonded wood chips, enabling it to withstand greater external forces and ensuring the durability of the bonding effect. Attached Figure Description

[0032] Figure 1 Structural characterization diagram of psyllium gum-ferulic acid;

[0033] Figure 2 Viscosity data graph for psyllium husk gum-ferulic acid green adhesive;

[0034] Figure 3Tensile analysis diagram of psyllium husk gum-ferulic acid green adhesive;

[0035] Figure 4 This image illustrates the application of psyllium husk gum-ferulic acid green adhesive.

[0036] Figure 5 A comparison chart showing the odor of psyllium husk gum-ferulic acid green adhesive and commercially available adhesives. Detailed Implementation

[0037] To enable those skilled in the art to understand the technical solution of the present invention more clearly, the present invention will be further described in detail below with reference to the embodiments and accompanying drawings, but the embodiments of the present invention are not limited thereto.

[0038] Example 1

[0039] The preparation steps of a green adhesive based on psyllium husk gum and ferulic acid are as follows:

[0040] Prepare experimental equipment and reagents: Select clean, dry glass reaction vessels of appropriate volume, such as 500ml round-bottom flasks, and equip them with magnetic stirrers, thermometers, reflux condensers, and other devices.

[0041] Weigh out analytical grade ferulic acid and psyllium husk gum, as well as reagents such as N,N-dimethylformamide (DMF), N,N'-diisopropylcarbodiimide (DIC), 4-dimethylaminopyridine (DMAP), and anhydrous ethanol.

[0042] Ensure that the experimental environment temperature is stable at around 25℃ and the relative humidity is maintained at 40-60% to reduce the impact of environmental factors on the experiment.

[0043] Dissolving ferulic acid (S1): Slowly add an accurate amount of ferulic acid into a round-bottom flask containing an appropriate amount of N,N-dimethylformamide (DMF).

[0044] Turn on the magnetic stirrer and set the stirring speed to 250 r / min to fully dissolve the ferulic acid.

[0045] During the dissolution process, a thermometer is used to monitor the solution temperature in real time to ensure that the temperature is maintained between 25-30℃.

[0046] If the temperature is too high or too low, the stirring speed can be adjusted appropriately or cooling or heating measures can be taken.

[0047] Continue stirring for 45 minutes until ferulic acid is completely dissolved, forming a clear and transparent solution.

[0048] Add DIC (S2): After ferulic acid is completely dissolved, use a pipette to accurately measure an appropriate amount of DIC at a molar ratio of 1:1 and slowly add it dropwise to the ferulic acid DMF solution.

[0049] During the dropwise addition, maintain stirring to ensure thorough mixing of DIC with the solution. After the addition is complete, place the reaction vessel in an oil bath at 30°C and react for 2.5 hours.

[0050] During the reaction, closely observe the color and state changes of the solution and record any phenomena that may occur.

[0051] Add DMAP and react (S3): After the reaction in the solution in S2 is complete (the reaction progress can be determined by thin-layer chromatography or other suitable analytical methods), accurately weigh an appropriate amount of 4-dimethylaminopyridine (DMAP) according to the molar ratio of ferulic acid to DMAP of 6:5 and add it to the reaction solution.

[0052] Continue stirring for 30 minutes, while maintaining the reaction temperature at 30°C.

[0053] To ensure the reaction proceeds fully, the stirring speed can be adjusted to 300 r / min.

[0054] Mixing reaction with psyllium gum (S4): In another clean container, dissolve psyllium gum in an appropriate amount of deionized water to prepare a psyllium gum solution with a concentration of 15% wt.

[0055] After reaction S3 is complete, slowly pour the dissolved psyllium gum solution into the round-bottom flask containing the ferulic acid reaction product and mix thoroughly. Seal the reaction vessel and allow it to react at room temperature overnight (approximately 12 hours). During the reaction, gently shake the reaction vessel periodically to ensure adequate contact of the reactants.

[0056] Termination of reaction and washing and filtration (S5): After the reaction has been allowed to proceed overnight, excess anhydrous ethanol is added to the reaction solution to terminate the reaction.

[0057] At this point, a precipitate will appear in the solution.

[0058] Transfer the reaction mixture to a Buchner funnel and filter. Wash the precipitate with anhydrous ethanol, using approximately 50 ml of anhydrous ethanol for each wash, for a total of three washes.

[0059] After each wash, continue filtration until the filtrate is clear.

[0060] Low-temperature drying and product collection (S6): Transfer the powder obtained from washing and filtration to a petri dish and place it in a vacuum drying oven for low-temperature drying.

[0061] The drying oven temperature was set at 50℃, the vacuum degree at 0.08MPa, and the drying time at 8 hours.

[0062] After drying, remove the petri dish and allow the powder to cool to room temperature to obtain the glycophenol complex.

[0063] Collect the glycophenolic complex in a dry, clean sample bottle, label it, and indicate the preparation date, batch number, and other information.

[0064] Preparation of green adhesive (S7): Weigh a certain amount of sugar-phenol complex, dissolve it in deionized water, and prepare a solution with a mass fraction of 5% wt.

[0065] During the dissolution process, a magnetic stirrer was used to stir at a speed of 300 r / min until the glycophenol complex was completely dissolved, forming a homogeneous and stable psyllium gum-ferulic acid green adhesive solution.

[0066] The prepared glycophenolic complex was characterized by FT-IR structure, such as... Figure 1 As shown.

[0067] Figure 1 The results showed that this method successfully grafted ferulic acid onto psyllium gum in a short time, and the amount of grafted ferulic acid was related to the reaction time.

[0068] Example 2

[0069] This embodiment is used to determine the viscous properties of the glycophenol complex prepared in S6 of Example 1.

[0070] Experimental instrument preparation: Select a TA DHR-2 rheometer equipped with a stainless steel parallel plate (25mm in diameter), and ensure that the instrument is calibrated and in normal working condition.

[0071] Before the experiment, the temperature control system of the rheometer was set to 25℃ and stabilized for 30 minutes to ensure the accuracy of the test environment temperature.

[0072] Sample preparation: Take an appropriate amount of the glycophenolic complex prepared in Example 1 and prepare a 5% wt green binder solution according to the method in S7 of Example 1. Carefully transfer the solution onto the sample stage of the rheometer, ensuring that the sample is evenly distributed and free of air bubbles.

[0073] Oscillation scan measurement: Oscillation scan measurement in the range of 0.1 to 100 (1 / s) was performed using the Viscosity Curve mode of the rheometer.

[0074] During the measurement process, the instrument automatically records the viscosity data of the adhesive at different shear rates.

[0075] Each measurement point was measured three times, and the average value was taken as the viscosity value at that point to reduce experimental error.

[0076] Results Analysis: Results Figure 2 This indicates that ferulic acid-modified grafted psyllium gum can effectively improve the viscosity of psyllium gum, and the viscosity of the glycophenolic complex grafted for 10 hours is relatively high.

[0077] As can be seen from the data curves, the viscosity of the adhesive first decreases and then tends to stabilize as the shear rate increases.

[0078] This indicates that the adhesive has certain shear-thinning properties. At low shear rates, the intermolecular interactions are strong and the viscosity is high; while at high shear rates, the molecular chains are stretched and oriented, the intermolecular forces are weakened, and the viscosity decreases.

[0079] The viscosity of the glycophenolic complex grafted for 10 hours was consistently higher than that of samples grafted for other times throughout the measurement range. This indicates that its molecular structure is more rational and forms a more stable network structure, thus exhibiting better viscosity properties.

[0080] Example 3

[0081] This embodiment is used to evaluate the tensile properties of the green adhesive prepared in S7 of Example 1 at a mass fraction of 5% (wt).

[0082] Experimental material preparation: Select uniform and smooth wood chips as the base material. Cut the wood chips into 16cm × 4cm pieces, ensuring that each piece has a uniform surface area of ​​60cm². 2 .

[0083] Lightly sand the surface of the wood chips with sandpaper to increase the adhesion between the adhesive and the wood chips. Prepare the green adhesive prepared in Example 1 and a tensile testing machine with an accuracy of 0.1 N.

[0084] Sample preparation: Take an equal amount of the prepared green adhesive and apply it evenly to the bonding surface of the wood chips using a glass rod, ensuring that the adhesive is evenly distributed and of uniform thickness.

[0085] After applying the adhesive, press the two wood chips with the adhesive applied to their adhesive surfaces together and apply a certain amount of pressure (approximately 1 kg / cm²). 2 This allows the two wood pieces to bond tightly together. The bonded wood pieces are then left to stand at room temperature for 24 hours to allow the adhesive to fully cure.

[0086] Tensile test: The wood chip with the green adhesive backing layer is mounted on the tensile testing machine and the position of the wood chip is adjusted so that it is at a peel angle of 180° relative to the base material.

[0087] Set the peel rate of the tensile testing machine to 10 mm / min, start the tensile testing machine to perform a 180° peel adhesion test, and record the tensile data in real time during the test until the wood chips are completely separated.

[0088] Each sample was tested 5 times, and the average value was taken as the maximum tensile force and tensile duration of the sample.

[0089] Results Analysis: Results Figure 3 The results show that the psyllium gum-ferulic acid green adhesive prepared by this method has significantly better maximum tensile strength and tensile endurance than raw sugar, and the strength and tensile endurance of the wood chips bonded by psyllium gum are significantly enhanced. Compared with raw sugar, the maximum tensile strength of this green adhesive is increased by 300 N, and the tensile endurance is extended by about 3 / 1 time.

[0090] This indicates that the grafting modification of ferulic acid significantly enhances the adhesive properties of psyllium husk, enabling it to withstand greater tensile forces and achieve better performance in practical applications.

[0091] Example 4

[0092] This embodiment is used to evaluate the adhesion comparison between the green adhesive prepared in S7 of Example 1 and a commercially available children's adhesive.

[0093] Experimental materials preparation: Select a variety of commercially available children's adhesives, as well as colored craft paper of the same specifications as in Example 3.

[0094] Prepare experimental tools such as scissors and tweezers.

[0095] Sample preparation: Take appropriate amounts of the green adhesive prepared in Example 1 and various commercially available children's adhesives, and apply them evenly to the same location on colored craft paper, keeping the application area and thickness as consistent as possible. Prepare 3 samples for each adhesive.

[0096] Adhesion test: Place two pieces of colored craft paper coated with adhesive together and press gently to make them stick together tightly.

[0097] Place the glued handmade paper at room temperature for 24 hours to allow the adhesive to fully cure.

[0098] Results observation and analysis: The results are as follows Figure 4 As shown, the green adhesive prepared by this method adheres more tightly when used in the application of colored handmade paper.

[0099] Observations revealed that the handmade paper bonded with the green adhesive of this invention did not separate after slight tearing, and the paper fibers at the bonding point were partially intertwined; while some commercially available children's adhesives bonded handmade paper easily separated when torn, and the paper fibers at the bonding point were not tightly bonded.

[0100] This indicates that the green adhesive of the present invention has a better bonding effect in the bonding application of colored handmade paper and can meet the requirements of higher bonding strength.

[0101] Example 5

[0102] This example is used to evaluate the odor comparison between the green adhesive prepared in S7 of Example 1 and commercially available children's adhesive.

[0103] Experimental preparation: Prepare multiple transparent sealed containers of the same size. Place the green adhesive prepared in Example 1 and various commercially available children's adhesives into different containers, with 3 copies of each adhesive to ensure that the sample amount is the same.

[0104] After sealing the container, place it in a well-ventilated environment at a temperature of 25°C.

[0105] Odor assessment: Ten volunteers with normal sense of smell were invited to participate in the odor assessment experiment.

[0106] Volunteers are required to rinse their mouths with water before the assessment to reduce the impact of bad breath on their sense of smell.

[0107] Each time a container was opened, volunteers were asked to smell it and rate it based on the intensity and irritation of the smell. The rating scale was 1-5 points, where 1 point was a very faint smell with no irritation and 5 points was a strong smell with a strong irritation.

[0108] Each sample was rated by 10 volunteers, and the average score was taken as the odor score of that sample.

[0109] Results Analysis: The results are as follows Figure 5 As shown, the green adhesive prepared by this method has a very slight odor.

[0110] Experimental data show that the green adhesive of this invention has an average odor score of approximately 1.5 points, while most commercially available children's adhesives have an average odor score between 3 and 4 points. This indicates that the green adhesive of this invention has a significant advantage in terms of odor, is more environmentally friendly and healthier, and is more suitable for applications where odor requirements are high, such as children's crafts and food packaging.

[0111] The above description is merely a further embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope disclosed in the present invention, based on the technical solution and concept of the present invention, shall fall within the scope of protection of the present invention.

Claims

1. A method for efficient preparation of a green psyllium gum-ferulic acid adhesive, characterized by: The method comprises the following steps: Step one: dissolve ferulic acid in N,N-dimethylformamide; Step two: add an appropriate amount of N,N'-diisopropyl carbodiimide to the dissolved ferulic acid solution, wherein the molar ratio of ferulic acid to N,N'-diisopropyl carbodiimide is 1:1; Step three: after the solution in step two is reacted, an appropriate amount of 4-dimethylaminopyridine is added and reacted for 30 min, and the molar ratio of ferulic acid to 4-dimethylaminopyridine is 6:5; Step four: mix the dissolved plantain glue with the solution obtained in step three and react overnight; Step five: after the reaction is completed, add anhydrous ethanol to terminate the reaction, and wash and filter with anhydrous ethanol; Step six: low-temperature dry the powder obtained by washing and filtering to obtain plantain glue-ferulic acid; Step seven: dissolve the plantain glue-ferulic acid in deionized water with a mass fraction of 5%wt, stir and dissolve to obtain a plantain glue-ferulic acid green adhesive.

2. A method of efficiently preparing a green adhesive of psyllium gum-ferulic acid according to claim 1, characterized by: The dissolution temperature of ferulic acid in N,N-dimethylformamide in step one is 20-30℃; The stirring speed is 200-300r / min, and the dissolution time is 30-60min.

3. A process for the preparation of high efficient colloidal psyllium-gallic acid green adhesive as claimed in claim 2, wherein: After adding N,N'-diisopropyl carbodiimide in step two, the reaction temperature is controlled at 25-35℃, and the reaction time is 2-3h.

4. A process for the preparation of a green adhesive of psyllium gum-ferulic acid as claimed in claim 3, wherein: The concentration of the dissolved plantain glue in step four is 10-20%wt, and the stirring speed during the mixing reaction is 100-150r / min.

5. A process for the preparation of high efficient colloidal psyllium-gallic acid green adhesive as claimed in claim 4, wherein: The anhydrous ethanol is washed for 3-5 times, and each washing time is 5-15min.

6. A process for the preparation of high efficient colloidal psyllium-gallic acid green adhesive as claimed in claim 5, wherein: The low-temperature drying temperature in step six is 40-60℃, and the drying time is 6-10h.

7. A process for the preparation of high efficient psyllium gum-ferulic acid green adhesive as claimed in claim 6, wherein: The viscosity of the adhesive is not less than 1000 mPa·s at 25℃ and a shear rate of 10 (1 / s) .

8. A process for the preparation of high efficient colloidal psyllium-gallic acid green adhesive as claimed in claim 7, wherein: When the adhesive is subjected to 180° peeling adhesion test, the maximum tensile force is not less than 50N and the tensile duration is not less than 30min on a wood piece with an adhesive surface size of 60cm² at a peeling rate of 10mm / min.

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