Preparation method of cottonseed protein-based adhesive capable of being used for underwater bonding

Abstract

The invention discloses a preparation method of a cottonseed protein-based adhesive capable of being used for underwater bonding, which comprises the following steps: dissolving plant polyphenol in water, adjusting the pH value with sodium hydroxide, then adding cellulose, and uniformly mixing to obtain a mixture A; adding cottonseed protein powder into methanol, then adding a surfactant, stirring at a low speed at normal temperature, and then drying to obtain a mixture B; and adding the mixture B into the mixture A, ultrasonically stirring and uniformly mixing, adding metal salt and a cross-linking agent, and continuously ultrasonically stirring to obtain the cottonseed protein-based adhesive. The preparation method has the following beneficial effects that hydrophobic cottonseed protein and plant polyphenol are complexed through metal ions to prepare a water-insoluble adhesive, a hydrogen bond is formed between the cottonseed protein and polyphenol to endow the material with excellent adhesive property, and certain mechanical property and strength are kept through an ionic cross-linking method; therefore, the method is used for fixing and repairing the vegetation in the underwater environment.

Description

Technical Field

[0001] The invention belongs to the technical field of adhesives, and in particular relates to a method for preparing a cottonseed protein-based adhesive that can be used for underwater bonding. Background Art

[0002] Adhesives are widely used in our daily life and industry. Currently, most adhesives on the market can only achieve adhesion to dry objects in an air environment. However, in practical applications, it is often necessary to bond wet surfaces or achieve adhesion in liquid media, such as implantable devices and wound dressings in the medical field, water-based energy devices, underwater sensors, underwater material leak repair and marine industry. Therefore, the development of new underwater adhesives that can be used in wet / underwater environments has become an important goal in the field of adhesive research.

[0003] Most protein-based adhesives in the prior art use soybean protein as the protein base, and the structure of soybean protein is a typical spherical structure, with the hydrophilic group exposed on the outside and the hydrophobic group and reactive sites coated on the inside, which results in high viscosity, poor water resistance and low mechanical strength of the materials prepared from soybean protein. At present, there are many studies on the modification of soybean protein-based materials, but in the existing technical literature and patents, no attempt to use cottonseed protein as a protein matrix to prepare adhesives has been found. Summary of the invention

[0004] An object of the present invention is to solve at least the above problems and / or disadvantages and to provide at least the advantages which will be described hereinafter.

[0005] In order to achieve these purposes and other advantages according to the present invention, a method for preparing a cottonseed protein-based adhesive that can be used for underwater bonding is provided, characterized in that it comprises:

[0006] Step 1, dissolving plant polyphenols in water, adjusting the pH with sodium hydroxide, then adding cellulose and mixing well to obtain a mixture A;

[0007] Step 2, adding cottonseed protein powder to methanol, then adding a surfactant, stirring at low speed at room temperature, and then drying to obtain a mixture B;

[0008] Step 3: Add mixture B to mixture A, then stir and mix evenly by ultrasonic stirring, then add metal salt and cross-linking agent, and continue ultrasonic stirring to obtain cottonseed protein-based adhesive.

[0009] Preferably, in step 1, the mass ratio of plant polyphenols, water and plant cellulose is 1-5:30-50:0.1-3, and the pH is adjusted to 8-10.

[0010] Preferably, in step 1, the plant polyphenols are one or more of tea polyphenols, clove polyphenols, apple polyphenols, grape polyphenols, flavonoid compounds, and phenolic acid compounds.

[0011] Preferably, in step 1, the cellulose is one of methyl cellulose, hydroxymethyl cellulose, hydroxyethyl cellulose and hydroxypropyl methyl cellulose.

[0012] Preferably, in step 2, the mass ratio of cottonseed protein powder, methanol and surfactant is 50-90:10-40:0.01-5.

[0013] Preferably, in step 2, the surfactant is one of sodium dodecyl sulfonate and sodium dodecylbenzene sulfonate.

[0014] Preferably, in the step 2, the low-speed stirring speed is 200-250 rpm, the stirring time is 1-3 hours, the drying temperature is 40-60° C., and the drying time is 2-5 hours.

[0015] Preferably, in step three, the mass ratio of mixture A to mixture B is 1-2.5:2-3.5, the amount of metal salt added is 1-5% of the cottonseed protein powder in mixture B, and the amount of cross-linking agent added is 1-3% of the total mass of mixture A and mixture B.

[0016] Preferably, in step 3, the metal salt is FeSO 4 、FeCl 3 AgNO 3 ,CuSO 4 、CeCl 3 The cross-linking agent is one of ethylene glycol diglycidyl ether, 1,4-butanediol glycidyl ether, 1,6-hexanediol glycidyl ether, glycerol triglycidyl ether, furfuryl alcohol or furfural resin.

[0017] Preferably, in step three, the stirring speed is 600-800 rpm, and the stirring time is 2-4 hours.

[0018] Preferably, before adding the cross-linking agent in step 3, the cross-linking agent is pretreated by preheating the beaker in a 40°C water bath for 30 minutes, then adding 2wt% of ethylenediamine, 3wt% of lauryl aldehyde, 65wt% of cross-linking agent, and 30wt% of water to the beaker according to mass percentage, and then stirring magnetically, adjusting the pH to 8-10 with NaOH after stirring evenly, and then heating to 85-110°C for reaction for 5-10 minutes to obtain a pretreated cross-linking agent.

[0019] The present invention has at least the following beneficial effects: hydrophobic cottonseed protein and plant polyphenols are complexed by metal ions to prepare a water-insoluble adhesive, hydrogen bonds are formed between cottonseed protein and polyphenols to give the material excellent bonding properties, and certain mechanical properties and strength are maintained by ionic crosslinking, while plant cellulose is introduced into the system to further enhance the strength of the adhesive, so that it can be used for fixing and repairing vegetation in underwater environments. Pretreatment of the crosslinking agent also helps to enhance the crosslinking effect.

[0020] Other advantages, objectives and features of the present invention will be embodied in part through the following description, and in part will be understood by those skilled in the art through study and practice of the present invention. DETAILED DESCRIPTION

[0021] The present invention is described in further detail below so that those skilled in the art can implement it according to the description.

[0022] Example 1

[0023] A method for preparing a cottonseed protein-based adhesive that can be used for underwater bonding, characterized by comprising:

[0024] Step 1, dissolve 0.45 kg of tea polyphenols in 4.5 kg of water, adjust the pH to 10 with sodium hydroxide, then add 0.05 kg of hydroxymethyl cellulose, mix well, and obtain mixture A;

[0025] Step 2: Add 5.5 kg of cottonseed protein powder to 1.95 kg of methanol, then add 0.05 kg of sodium dodecyl sulfate, stir at 200 rpm for 2 h at room temperature, and then dry at 50° C. for 2 h to obtain a mixture B;

[0026] Step 3: Add mixture B to mixture A, and then stir with ultrasonic stirring at 650 rpm for 2.5 h to mix well. Then add 0.11 kg AgNO 3 , 0.15 kg of furfuryl alcohol, continue ultrasonic stirring, stirring speed 650 rpm, stirring for 2.5 hours to obtain a cottonseed protein-based adhesive.

[0027] Example 2

[0028] A method for preparing a cottonseed protein-based adhesive that can be used for underwater bonding, characterized by comprising:

[0029] Step 1, dissolving 0.45 kg of grape polyphenols in 4.5 kg of water, adjusting the pH to 10 with sodium hydroxide, then adding 0.05 kg of hydroxymethyl cellulose, and mixing well to obtain a mixture A;

[0030] Step 2: Add 5.5 kg of cottonseed protein powder to 1.95 kg of methanol, then add 0.05 kg of sodium dodecyl sulfate, stir at 200 rpm for 2 h at room temperature, and then dry at 50° C. for 2 h to obtain a mixture B;

[0031] Step 3: Add mixture B to mixture A, and then stir with ultrasonic stirring at 650 rpm for 2.5 h to mix well. Then add 0.11 kg FeSO 4 , 0.15 kg of ethylene glycol diglycidyl ether, continue ultrasonic stirring, stirring speed 650 rpm, stirring for 2.5 hours to obtain a cottonseed protein-based adhesive.

[0032] Example 3

[0033] A method for preparing a cottonseed protein-based adhesive that can be used for underwater bonding, characterized by comprising:

[0034] Step 1, dissolving 0.45 kg of apple polyphenols in 4.5 kg of water, adjusting the pH to 10 with sodium hydroxide, then adding 0.05 kg of hydroxymethyl cellulose, mixing well, to obtain a mixture A;

[0035] Step 2: Add 5.5 kg of cottonseed protein powder to 1.95 kg of methanol, then add 0.05 kg of sodium dodecyl sulfate, stir at 200 rpm for 2 h at room temperature, and then dry at 50° C. for 2 h to obtain a mixture B;

[0036] Step 3: Add mixture B to mixture A, and then stir with ultrasonic stirring at 650 rpm for 2.5 h to mix well. Then add 0.11 kg FeCl 3 , 0.15 kg of propylene glycol triglycidyl ether, continue ultrasonic stirring, stirring speed 650 rpm, stirring for 2.5 hours to obtain a cottonseed protein-based adhesive.

[0037] Example 4

[0038] The difference between this embodiment and embodiment 1 is that before adding furfuryl alcohol in step 3, furfuryl alcohol is pretreated by preheating the beaker in a 40°C water bath for 30 minutes, then adding 0.02 kg of ethylenediamine, 0.03 kg of lauryl aldehyde, 0.65 kg of furfuryl alcohol, and 0.3 kg of water into the beaker, followed by magnetic stirring, and after stirring evenly, adjusting the pH to 8 with NaOH, and then heating to 90°C for reaction for 10 minutes to obtain a pretreated cross-linking agent, and adding the pretreated furfuryl alcohol solution to step 3 according to the same amount of furfuryl alcohol as in embodiment 1, and the remaining steps are consistent with embodiment 1.

[0039] Comparative Example 1

[0040] The difference between this comparative example and Example 1 is that step 1 is: dissolving 0.5 kg of tea polyphenols in 4.5 kg of water, adjusting the pH to 10 with sodium hydroxide, and mixing to obtain mixture A.

[0041] The remaining steps are consistent with those in Example 1.

[0042] Comparative Example 2

[0043] The difference between this comparative example and Example 1 is that step three is: adding mixture B to mixture A, and then ultrasonically stirring at a stirring speed of 650 rpm, stirring for 2.5 hours until the mixture is evenly mixed, adding 0.15 kg of furfuryl alcohol thereto, continuing ultrasonically stirring at a stirring speed of 650 rpm, stirring for 2.5 hours to obtain an adhesive.

[0044] The remaining steps are consistent with those in Example 1.

[0045] Comparative Example 3

[0046] The difference between this comparative example and Example 1 is that step 3 is: adding mixture B to mixture A, and then ultrasonically stirring at a stirring speed of 650 rpm, stirring for 2.5 hours until the mixture is evenly mixed, and then adding 0.11 kg of AgNO 3 , continue ultrasonic stirring, stirring speed 650rpm, stirring for 2.5h, to obtain an adhesive. The remaining steps are consistent with Example 1.

[0047] Comparative Example 4

[0048] The difference between this comparative example and Example 1 is that step one is: dissolving 0.5 kg of tea polyphenols in 4.5 kg of water, adjusting the pH to 10 with sodium hydroxide, and mixing to obtain mixture A; step three is: adding mixture B to mixture A, and then ultrasonically stirring at a stirring speed of 650 rpm, stirring for 2.5 hours to obtain an adhesive after mixing evenly.

[0049] The remaining steps are consistent with those in Example 1.

[0050] Comparative Example 5

[0051] The traditional method for preparing soy protein adhesive is as follows: dissolve 2.5 kg of soy protein in 0.75 L of water, stir at room temperature for 10 minutes at a stirring speed of 100 r / min, add 0.3 kg of lime milk and stir until completely dissolved, 0.4 kg of sodium hydroxide solution and stir until completely dissolved, and 0.5 kg of sodium silicate and stir until completely dissolved, and continue stirring for 30 minutes to obtain the soy protein adhesive.

[0052] Examples 1 to 3 and Comparative Examples 1 to 5 were measured according to the performance measurement method of common plywood in GB / T 9846-2015, wherein the dry bonding strength was measured directly without soaking in water; and the Class II bonding strength was measured after soaking in hot water at 63°C for 3 hours. The test results are shown in Table 1.

[0053] Table 1

[0054]

[0055]

[0056] As can be seen from Table 1, Examples 1 to 3 of the present invention use metal salts to make metal ions complex the hydrophobic cottonseed protein with plant polyphenols, and cellulose is also added to prepare the water-insoluble adhesive, and the dry bonding strength and the type II bonding strength after wetting are both high; Example 4 pre-treats the added furfuryl alcohol, so that it has stronger stability after participating in the system reaction, thereby further improving the bonding strength; while the bonding strength of Comparative Example 1 decreases due to the absence of cellulose, and the bonding strength of Comparative Example 2 is significantly reduced due to the absence of metal ions; Comparative Example 3 does not add a cross-linking agent, but due to the presence of metal ions, the cottonseed protein and plant polyphenols can still be complexed, and the bonding strength is only slightly reduced; Comparative Example 4 does not add cellulose, a cross-linking agent and metal ions, and the cottonseed protein and plant polyphenols cannot be complexed, and the bonding strength is even lower; Comparative Example 5 uses a soybean protein adhesive prepared by a traditional method, and its dry bonding strength is low, and it cannot be used after soaking in water.

[0057] Although the embodiments of the present invention have been disclosed as above, they are not limited to the applications listed in the specification and the implementation modes, and they can be fully applied to various fields suitable for the present invention. For those familiar with the art, additional modifications can be easily implemented. Therefore, without departing from the general concept defined by the claims and the scope of equivalents, the present invention is not limited to the specific details and the illustrations shown and described herein.

Claims

1. A method for preparing a cottonseed protein-based adhesive that can be used for underwater bonding, characterized in that: include: Step 1, dissolving plant polyphenols in water, adjusting the pH with sodium hydroxide, then adding cellulose and mixing well to obtain a mixture A; Step 2: adding cottonseed protein powder to methanol, adding a surfactant, stirring at low speed at room temperature, and then drying to obtain a mixture B; Step 3: Add mixture B to mixture A, then stir and mix evenly by ultrasonic stirring, then add metal salt and cross-linking agent, and continue ultrasonic stirring to obtain cottonseed protein-based adhesive.

2. The method for preparing the cottonseed protein-based adhesive for underwater bonding according to claim 1, characterized in that: In the step 1, the mass ratio of plant polyphenols, water and plant cellulose is 1-5:30-50:0.1-3, and the pH is adjusted to 8-10.

3. The method for preparing the cottonseed protein-based adhesive for underwater bonding according to claim 1, characterized in that: In the step 1, the plant polyphenols are one or more of tea polyphenols, clove polyphenols, apple polyphenols, grape polyphenols, flavonoid compounds, and phenolic acid compounds.

4. The method for preparing the cottonseed protein-based adhesive for underwater bonding according to claim 1, characterized in that: In the step 1, the cellulose is one of methyl cellulose, hydroxymethyl cellulose, hydroxyethyl cellulose and hydroxypropyl methyl cellulose.

5. The method for preparing the cottonseed protein-based adhesive for underwater bonding according to claim 1, characterized in that: In the step 2, the mass ratio of cottonseed protein powder, methanol and surfactant is 50-90:10-40:0.01-5.

6. The method for preparing the cottonseed protein-based adhesive for underwater bonding according to claim 1, characterized in that: In the step 2, the surfactant is one of sodium dodecyl sulfonate and sodium dodecylbenzene sulfonate.

7. The method for preparing the cottonseed protein-based adhesive for underwater bonding according to claim 1, characterized in that: In the step 2, the low-speed stirring speed is 200-250 rpm, the stirring time is 1-3 hours, the drying temperature is 40-60° C., and the drying time is 2-5 hours.

8. The method for preparing the cottonseed protein-based adhesive for underwater bonding according to claim 1, characterized in that: In the step 3, the mass ratio of mixture A to mixture B is 1-2.5:2-3.5, the amount of metal salt added is 1-5% of the cottonseed protein powder in mixture B, and the amount of cross-linking agent added is 1-3% of the total mass of mixture A and mixture B.

9. The method for preparing the cottonseed protein-based adhesive for underwater bonding according to claim 1, characterized in that: In the step three, the metal salt is one of FeSO4, FeCl3, AgNO3, CuSO4, and CeCl3, and the cross-linking agent is one of ethylene glycol diglycidyl ether, 1,4-butanediol glycidyl ether, 1,6-hexanediol glycidyl ether, propylene glycol triglycidyl ether, furfuryl alcohol, or furfural resin.

10. The method for preparing the cottonseed protein-based adhesive for underwater bonding according to claim 1, characterized in that: In the step 3, the stirring speed is 600-800 rpm, and the stirring is performed for 2-4 hours.

Images