CN113105847B

CN113105847B - Protein-based adhesive as well as preparation method and application thereof

Info

Publication number: CN113105847B
Application number: CN202110330502.0A
Authority: CN
Inventors: 李玥; 高强; 黄新鑫; 李建章; 李京超
Original assignee: Beijing Forestry University
Current assignee: Beijing Forestry University
Priority date: 2021-03-24
Filing date: 2021-03-24
Publication date: 2022-07-05
Anticipated expiration: 2041-03-24
Also published as: CN113105847A

Abstract

The invention belongs to the technical field of adhesives, and particularly relates to a protein-based adhesive and a preparation method thereof. The adhesive is prepared from the following raw materials: protein, 1, 2-epoxy-9-decene, urushiol and calcium oxide. The protein-based adhesive disclosed by the invention is free of toxic substances, urushiol is a natural substance, the cost is lower, the preparation process is simple, the reaction activity of the product is high, and the protein-based adhesive can be industrially applied. The adhesive disclosed by the invention has good plasticity, can be processed, molded and cured underwater, and can be used as a material for underwater 3D printing.

Description

Protein-based adhesive and preparation method and application thereof

Technical Field

The invention belongs to the technical field of adhesives, and particularly relates to a protein-based adhesive as well as a preparation method and application thereof.

Background

The protein-based adhesive has wide application in daily life, traffic construction, oceans, medical treatment and the like. Underwater bonding is a significant challenge because the creation of a weak boundary layer by the water on the substrate surface may prevent the adhesive from contacting the substrate surface. The traditional adhesive can not remove the direct contact between a hydration layer on the surface of a base material and the poor cohesion of the adhesive, and is difficult to realize underwater bonding. Previous researches mostly prepare protein-based adhesives through bionic catechol structures, generally realize underwater bonding (such as electrostatic interaction, hydrophobic interaction and the like) through a chemical bond crosslinking mode, but the adhesives are difficult to cure, the underwater bonding performance is poor, and meanwhile, a large amount of dopamine and non-biological materials are used, so that the cost is high, and the large-scale application is difficult in subsequent production application.

Disclosure of Invention

Aiming at the problems of poor underwater adhesive property and poor adhesive bonding property of the adhesive in the prior art, the invention extracts the adhesive with low cost and simple formula, and the adhesive is prepared from the following raw materials: protein, 1, 2-epoxy-9-decene, urushiol and calcium oxide.

According to the adhesive, 1, 2-epoxy-9-decene is introduced, an epoxy group of the 1, 2-epoxy-9-decene reacts with an amino group in protein to introduce an unsaturated bond into a protein molecule, so that a catechol structure is grafted to a protein molecular chain in a free radical polymerization manner to form modified protein. The long-chain R group in the urushiol can drain water on the surface of the base material, the catechol structure can form a strong hydrogen bond effect with the surface of the base material, so that strong adhesion is generated on different base materials, calcium oxide is added, calcium hydroxide is formed through hydration reaction, the calcium hydroxide can absorb the water on the surface of the base material, and is beneficial to generation and strengthening of adhesion performance, the formed crystal can improve the cohesive force of the adhesive, and meanwhile, calcium ions can be complexed with the catechol structure to form a multi-network system, so that the adhesive has strong underwater adhesion performance and adhesive bonding performance.

Preferably, the urushiol of the present invention is prepared by the following method:

adding absolute ethyl alcohol into natural lacquer, stirring, filtering to remove impurities, and evaporating alcohol in the filtrate by using a rotary evaporator to obtain urushiol.

Preferably, the molecular weight of the protein is 20000-60000. Protein with the molecular weight can generate strong adhesion after urushiol modifies the protein.

Preferably, the protein is soy protein isolate.

Preferably, the composition is prepared from the following components in parts by weight: 15-16 parts of protein, 5-6 parts of 1, 2-epoxy-9-decene, 7.5-8.5 parts of urushiol and 2.1-2.4 parts of calcium chloride.

Preferably, the raw materials for preparing the protein-based adhesive also comprise an initiator;

further preferably, the initiator is ammonium persulfate.

Preferably, the raw materials for preparing the protein-based adhesive also comprise a dispersing agent;

further preferably, the dispersant is water.

Preferably, raw materials for preparing the protein-based adhesive comprise 15-16 parts of isolated soy protein, 5-6 parts of 1, 2-epoxy-9-decene, 7.5-8.5 parts of urushiol, 0.09-0.1 part of ammonium persulfate, 2.1-2.4 parts of calcium oxide and 60 parts of water.

The invention also provides a preparation method of the protein-based adhesive, which comprises the following steps:

1) mixing the protein with water, reacting for 20-40 min at 70-80 ℃, adding 1, 2-epoxy-9-decene, and continuing to react for 20-40 min at 70-80 ℃;

2) adding urushiol into the mixture obtained by the reaction in the step 1), then adding ammonium persulfate, and stirring for reaction;

3) adding calcium oxide into the mixture obtained by the reaction in the step 2), and stirring to prepare the protein-based adhesive.

The method of the invention can open the molecular chain of the soybean protein agglomeration by using a physical heating method, increase the contact area of the 1, 2-epoxy-9-decene to the protein molecules and increase the active sites of the soybean protein.

Another object of the present invention is to protect the use of the protein-based adhesive of the present invention in underwater cementing.

Preferably, the use for underwater gluing of metals, wood, glass, resins, ceramics and proteinaceous materials.

Further preferably, the resin is rubber, polyurethane or foam.

The final purpose of the invention is to protect the application of the protein-based adhesive in underwater 3D printing.

The invention has the following beneficial effects:

(1) the urushiol has good compatibility with protein and 1, 2-epoxy-9-decene, and can be used for carrying out molecular modification on the protein at normal temperature under the condition of ammonium persulfate, so that the protein has a long-chain catechol structure, the long-chain structure can drain water, the catechol structure generates strong hydrogen bonds, the underwater cementing performance is realized, the adhesive uniformity is good, and the process performance is good.

(2) The invention does not add toxic substances to the soy protein-based protein adhesive, and the urushiol is also a natural substance, and has the advantages of low cost, simple preparation process, high efficiency, high reaction activity of the product, good manufacturability and low cost, and can be industrially applied.

(3) The invention adopts protein to replace synthetic material as the main chain, solves the problem that protein-based adhesives depend on fossil resources, and obtains modified soybean protein isolate by grafting urushiol with catechol structure to form a material capable of being strongly adhered underwater.

(4) Calcium hydroxide is formed by utilizing the hydration reaction of calcium oxide and water, so that the water on the surface of the base material can be absorbed, the contact between the adhesive and the base material can be favorably realized, the formed crystal and ion complexing can improve the cohesive force of the adhesive, and the adhesive has underwater adhesive bonding performance.

(5) The adhesive has good plasticity, can be processed, molded and cured underwater, and can be used as a material for underwater 3D printing.

(6) The underwater cementing adhesive also has a plurality of other properties, such as antibiosis, mildew resistance, fire resistance and the like.

Drawings

FIG. 1A, the adhesive is used for writing a character of 'BJDU' (Chinese character) under water; washing (III) of a glass plate written with 'BJDU' by water; the shaking (IV) of the glass plate under water is written as 'BJDU'; B. a schematic diagram of blocking a small hole with the diameter of 0.5 cm on a centrifugal tube by using the adhesive; C. the adhesive can bond various base materials underwater;

FIG. 2A shows the sample shape and size of the substrate. And B, lapping and testing different base material test pieces.

FIG. 3(A) is a schematic view of the protein-based adhesive applied to a gloved finger that can bend and straighten under water. (B) And preparing the adhesive into a strip-shaped object imaging picture by using a toy noodle machine. (C) The method comprises the steps of respectively preparing three-dimensional peach heart (1), crescent moon (2), watermelon corner (3), cube (4), triangular prism (4), cylinder (4) and ball (5) by using a mold, wherein the pressure resistance curve of the adhesive is in different shapes (triangular prism, cylinder and cube) (E), drawing a real object imaging picture of a pattern on the adhesive with the thickness of 0.5 cm coated on polypropylene (F), and extruding the real object imaging picture of a three-dimensional frame by using an injector underwater.

FIG. 4(A) is a graph showing the results of the test for mold resistance. (B) And (4) testing results of antibacterial performance. (C) And (5) a test result graph of the fire resistance.

Detailed Description

The following examples are intended to illustrate the invention but are not intended to limit the scope of the invention. Modifications or substitutions to methods, procedures, or conditions of the invention may be made without departing from the spirit and scope of the invention.

Unless otherwise specified, the technical means used in the examples are conventional means well known to those skilled in the art. Further, all the component materials used in the examples are known commercially available products.

The percent in the present invention means mass percent unless otherwise specified; but the percentage of the solution, unless otherwise specified, means that 100ml of the solution contains several grams of solute; the percentage between the liquids refers to the ratio of the volumes at 20 ℃.

The extraction method of urushiol in the examples: adding 30ml of absolute ethyl alcohol into 1g of raw lacquer, stirring for 5 minutes, carrying out suction filtration for 2 times, and removing impurities. Evaporating alcohol in the filtrate by using a rotary evaporator to obtain urushiol.

Example 1

The embodiment provides a preparation method of a multifunctional soy protein-based protein adhesive capable of 3D printing, wherein the adhesive is prepared according to the following weight ratio:

the preparation method provided by the embodiment specifically comprises the following steps:

(1) weighing the components according to the weight ratio, mixing 15 parts by weight of soybean protein isolate with 60 parts by weight of water, reacting for 30min at 75 ℃, then adding 5 parts by weight of 1, 2-epoxy-9-decene, and continuing to react for 30min at 75 ℃;

(2) adding 7.5 parts by weight of urushiol into the mixture obtained in the step (1), and adding 0.09 part by weight of ammonium persulfate and stirring at normal temperature for 5 min;

(3) and (3) adding 2.15 parts by mass of calcium oxide into the mixture obtained in the step (2), stirring for 5min at normal temperature, and discharging.

Example 1 the properties were as follows:

(1) adhesion properties under water

The prepared adhesive is filled into a needle tube, and the performances of underwater coating, bonding, scouring resistance, sealing performance and the like are tested after extrusion. The study results are shown in figure 1:

experimental results show that the soybean protein-based adhesive disclosed by the invention is extruded under water to write letters of BJDU (BJDU), cannot be diffused into water, and can be well adhered to a glass substrate. It has good adhesion to the glass surface when washed and shaken vigorously in water (see FIG. 1A).

A small hole with the diameter of 0.5 cm is manufactured on a centrifugal tube made of 50 ml of polypropylene material, so that water flows out of the small hole, the soybean protein-based adhesive is injected into the hole by an injector, and the hole can be quickly repaired to block the hole. Polytetrafluoroethylene is typically a poor adhesion due to low surface energy, and can be adhered underwater with the soy protein based adhesives of this study (see fig. 1B).

The adhesive of the embodiment has adhesive performance on many hydrophobic surfaces under water, such as rubber, polyurethane, foam and alumina ceramics. The soy protein based adhesive can also be used to adhere pigskin to a skin under water (see fig. 1C).

(2) Underwater cementing property

In this example, the soy protein-based adhesive is used to prepare an underwater adhesive test piece, and the adhesive strength is tested.

Different substrate test piece styles and sizes: see FIG. 2A

The lapping mode and the testing mode of test pieces with different base materials are as follows: see FIG. 2B

The preparation method comprises the following normal preparation processes:

sizing: the glue is applied and bonded under water, the glue application amount is 300g/m²。

Time: the mixture was placed under water for 48 h.

Bonding Strength (KPa) ═ (tension (N))/(bonding area (m ^2))

The bond strength test results in the lap joint test were as follows:

TABLE 1 bonding Strength in different Water environments

TABLE 2 bonding Strength at different Water temperatures

TABLE 3 bond Strength in different organic solvent environments

TABLE 4 bonding Strength in different pH environments

Experimental results show that the soybean protein-based adhesive has good underwater bonding strength to different base materials under different water environments, compared with the previously reported protein-based adhesive, the underwater bonding strength of the soybean protein-based adhesive can be improved from dozens of megapascals to hundreds of megapascals, the reinforcing effect is remarkable, and standard deviation calculation shows that the adhesive is good in stability.

(3) Underwater 3D printing performance

The prepared adhesive is filled into different molds to prepare objects with different shapes, and the objects are subjected to compression resistance test (the result is shown in figure 3).

Experimental results show that the soybean protein-based adhesive has the property similar to that of plasticine, has good plasticity in air and water, and can be straightened and bent when being coated on fingers wearing gloves under water (figure 3A). The adhesive, left in air for 10 minutes, was hand kneaded into various shapes (fig. 3(C5)), which were placed in a simulated noodle maker to make a continuous, stick of the adhesive (fig. 3B). In addition, the adhesive is filled into a purchased mould, and the adhesive with a specific shape can be obtained by extrusion molding and soaking molding in water and air for a period of time. The method can simply and rapidly realize the preparation of macroscopic three-dimensional shapes under water to obtain the adhesive in the shapes of a solid center, a crescent, a watermelon horn, a cube, a solid triangle, a cylinder and the like (figure 3 (C1-C4)). Further, different forms (triangular prism, cylinder, cube) are soaked under water for 48h and then subjected to a compression resistance test, and the compression strengths of the adhesives are 0.82MPa, 5.51MPa and 0.31MPa respectively (fig. 3D), which shows that the forms of the adhesives have great influence on the compression resistance. The method has a great application prospect in the aspect of preparing three-dimensional controllable materials. In addition, the adhesive is filled into a syringe and then smoothly and uniformly extruded from the syringe, and a material similar to a three-dimensional steel bar structure is constructed by layer-by-layer extrusion (fig. 3F). In order to achieve fine processing of the prepared material, when the prepared material is uniformly coated on PP (polypropylene), a sharp needle is used to draw a pattern on the surface of the material instead of a laser (fig. 3E), and then the excess material is removed as required to obtain a desired pattern. The operation is simple and convenient, and the method has great application prospect in the aspect of fine processing of different substrates.

(4) Mildew-proof, antibacterial and fireproof performance

The experimental result shows that the soybean protein-based adhesive has good mildew resistance, and the obtained adhesive still does not mildew after being placed for 15 days (as shown in figure 4A). In addition, the colibacillus resistance and the staphylococcus aureus resistance of the adhesive respectively reach 96.88% and 87.23% (as shown in fig. 4B). The maximum cracking temperature of the adhesive prepared in accordance with the present invention increased from 298.6 to 418.5, as compared to the pure blank, indicating that the adhesive is less dangerous to fire (the results are shown in FIG. 4C).

Example 2

the preparation method provided in this example includes the specific preparation steps as in example 1.

The performance test shows that the performance of the embodiment 2 is equivalent to that of the embodiment 1 in the adhesion performance, and compared with the embodiment 1, the underwater bonding strength and the hardness are both improved by 15%, and the underwater 3D printing and mildew-proof antibacterial flame retardant coating has ideal underwater 3D printing and mildew-proof antibacterial flame retardant performances.

Comparative examples 1 to 3

Comparative example 1: compared with example 1, only isolated soy protein and water were contained.

Comparative example 2: compared with the example 1, the soybean protein isolate, water, 1, 2-epoxy-9-decene, urushiol and ammonium persulfate are contained;

comparative example 3: compared with example 1, the product contains isolated soy protein, water, and calcium oxide

The experimental method comprises the following steps: example 1 the sample method is the same. The method for testing the underwater cementing strength comprises the following steps: the adhesive is coated on one piece of glass underwater, the other piece of glass is covered on the coated glass underwater, then the glass is pressed tightly by 0.2MPa force, the glass is placed in water for 48 hours, and then the glass is taken out and tested to have the shearing strength as the bonding strength by a mechanical testing machine at the temperature of 20 ℃.

The performance pairs are as follows in table 1:

TABLE 1

Adhesive

Adhesion under water

Underwater cementing

Underwater 3D printing

Mould proof

Antibacterial

Flame-retardant

Example 1

Good taste

225KPa

Good taste

Example 2

Good taste

260KPa

Good taste

Comparative example 1

Is free of

0

Is free of

Comparative example 2

In general

48KPa

Is free of

Good taste

Is free of

Comparative example 3

Is free of

0

Is free of

Good taste

Although the invention has been described in detail hereinabove by way of general description, specific embodiments and experiments, it will be apparent to those skilled in the art that many modifications and improvements can be made thereto based on the invention. Accordingly, such modifications and improvements are intended to be within the scope of the invention as claimed.

Claims

1. The protein-based adhesive is characterized in that raw materials for preparing the protein-based adhesive comprise 15-16 parts of isolated soy protein, 5-6 parts of 1, 2-epoxy-9-decene, 7.5-8.5 parts of urushiol, 0.09-0.1 part of ammonium persulfate, 2.1-2.4 parts of calcium oxide and 60 parts of water.

2. A method of preparing the protein-based adhesive of claim 1, comprising the steps of:

1) mixing the protein and water, reacting for 20-40 min at 70-80 ℃, then adding 1, 2-epoxy-9-decene, and continuing to react for 20-40 min at 70-80 ℃;

2) adding urushiol into the mixture obtained in the step 1), then adding ammonium persulfate, and stirring for reaction;

3) adding calcium oxide into the mixture obtained by the reaction in the step 2), and stirring for reaction.

3. Use of the protein-based adhesive of claim 1 in underwater adhesion.

4. Use according to claim 3, wherein the protein-based adhesive is used for underwater adhesion of metals, wood, glass, resins, ceramics and proteinaceous materials.

5. Use of the protein-based adhesive of claim 1 in underwater 3D printing.