High-bonding-strength environment-friendly adhesive and preparation method thereof

Abstract

The invention discloses a high-bonding-strength environment-friendly adhesive and a preparation method thereof, and the high-bonding-strength environment-friendly adhesive comprises the following components in parts by weight: 60-90 parts of composite viscous solid waste; 5-16 parts of a composite activator; 2-10 parts of a cross-linking agent; and 10 to 30 parts of water. The preparation method comprises the following steps: crushing, sieving, mixing and drying various viscous solid wastes to obtain composite viscous solid wastes for later use, adding the pretreated composite viscous solid wastes into a reaction kettle, adding the composite activator and half of water, and stirring for reaction to obtain activated solid waste slurry; adding a cross-linking agent and the other half of water into the activated solid waste slurry, and stirring for reaction to obtain modified slurry; and grinding the modified slurry, sieving, removing impurities, drying and crushing to obtain the environment-friendly adhesive with high bonding strength. According to the present invention, the resource utilization of the viscous solid waste can be completely achieved, the waste material is turned into treasure, the process is simple and environmentally friendly, the cost is low, and the prepared adhesive has characteristics of high bonding strength, good water resistance and good stability, and can be suitable for various scenes.

Description

Technical Field

[0001] This invention relates to the field of adhesive technology, specifically to a high-bonding-strength environmentally friendly adhesive and its preparation method. Background Technology

[0002] With the rapid development of industry and agriculture, the discharge of sticky solid wastes such as furfural residue, rubber powder, straw, bagasse, distiller's grains, and starch residue has been increasing year by year. These solid wastes often have a certain degree of natural or potential stickiness, but because their sticky components are encapsulated, have low activity, or contain impurities, they cannot be used directly as adhesives. Currently, they are mostly disposed of through landfilling and incineration, which not only wastes resources but also causes environmental problems such as soil and air pollution.

[0003] There are many types of adhesives available, including synthetic resin adhesives (such as urea-formaldehyde resin and phenolic resin) and natural polymer adhesives (such as starch adhesives and cellulose adhesives). Among them, synthetic resin adhesives have environmental problems such as formaldehyde release, and their raw materials rely on fossil resources, resulting in higher costs. While natural polymer adhesives are environmentally friendly, they mostly use pure natural polymers (such as starch and cellulose) as raw materials, failing to fully utilize solid waste resources, and have defects such as insufficient bonding strength and poor water resistance, and their costs are also relatively high.

[0004] Currently, some technologies exist for preparing adhesives from solid waste, but these technologies often have the following shortcomings: First, they rely on a single type of raw material and are mostly designed for the treatment of a specific type of solid waste, failing to achieve the synergistic utilization of sticky solid waste from multiple industries; second, the treatment methods are complex, requiring the addition of large amounts of chemical modifiers, which increases costs and may introduce environmental risks; third, they do not fully activate the sticky components of the solid waste itself, resulting in poor bonding performance or limited application scenarios; and fourth, some technologies employ processes such as acid hydrolysis and high-temperature melting, which have high energy consumption and demanding equipment requirements.

[0005] Therefore, how to develop a new type of adhesive that can fully activate the adhesiveness of viscous solid waste from multiple industries, with simple and environmentally friendly processes, low cost, and excellent bonding performance, and its preparation method, has become an urgent technical problem to be solved in the field of solid waste resource utilization and adhesives. Summary of the Invention

[0006] To address the above technical problems, this invention provides a high-strength environmentally friendly adhesive and its preparation method that can fully activate the inherent viscosity of sticky solid waste from multiple industries, is simple and environmentally friendly in process, low in cost, and exhibits excellent bonding performance.

[0007] The technical solution is as follows:

[0008] The first aspect of this invention provides a high-bonding-strength environmentally friendly adhesive, the key feature of which is that, by weight, it comprises the following components:

[0009] 60-90 parts of composite viscous solid waste;

[0010] Activator 5-16 parts;

[0011] 2-10 parts of crosslinking agent;

[0012] 10-30 parts water.

[0013] Preferably, the composite viscous solid waste includes at least three of the following: furfural residue, rubber powder, straw, bagasse, distiller's grains, and starch residue, and is mixed in any proportion.

[0014] Preferably, the activator is a composite activator, comprising a biological enzyme preparation and an inorganic weak base, wherein the mass ratio of the biological enzyme preparation to the inorganic weak base is 1:(2-5).

[0015] The biological enzyme preparation includes at least one of cellulase, hemicellulase, and amylase, and the inorganic weak base includes at least one of sodium bicarbonate and potassium carbonate.

[0016] Preferably, the crosslinking agent is a natural polymer crosslinking agent, including at least one of chitosan, pectin, and konjac flour.

[0017] A second aspect of the present invention provides a method for preparing a high-bonding-strength environmentally friendly adhesive as described in the first aspect of the present invention, comprising the following steps:

[0018] S1: Pretreatment of composite viscous solid waste: Crush, sieve, mix and dry various types of viscous solid waste to obtain composite viscous solid waste for later use;

[0019] S2: Low-temperature activation: The pretreated composite viscous solid waste is added to the reactor, along with the composite activator and half of the water. The mixture is stirred and reacted to obtain activated solid waste slurry.

[0020] S3: Crosslinking modification: Add crosslinking agent and the remaining half of the water to the activated solid waste slurry, stir and react to obtain the modified slurry;

[0021] S4: Post-processing: Grind, sieve, remove impurities, dry, and pulverize the modified slurry to obtain an environmentally friendly adhesive with high bonding strength.

[0022] Preferably, in step S1, the particle size of various viscous solid wastes after crushing is passed through an 80-120 mesh sieve, and dried at 60-80℃ for 2-3 hours until the moisture content is ≤5%.

[0023] Preferably, in step S2, the amount of biological enzyme preparation added to the composite activator is 0.5-2% of the weight of the composite viscous solid waste, and the amount of inorganic weak alkali added is 1-10% of the weight of the composite viscous solid waste.

[0024] Preferably, in step S2, the reaction temperature is controlled at 35-55℃, the rotation speed is 100-220 r / min, and the temperature is maintained and stirred for 2-4 hours for activation.

[0025] Preferably: in step S3, the reaction temperature is adjusted to 45-65℃, the rotation speed is maintained at 100-220 r / min, and the mixture is kept warm and stirred for 1-3 hours;

[0026] Specifically, when the required bonding strength is ≥3.5MPa, the amount of crosslinking agent added is 7-10 parts, and when the required bonding strength is <3.5MPa, the amount of crosslinking agent added is 2-6 parts.

[0027] Preferably, in step S4, a colloid mill is used for grinding for 30-65 minutes, followed by passing through a 200-320 mesh sieve to remove insufficiently activated impurity particles, and then vacuum drying at 50-70°C until the moisture content is ≤6%.

[0028] The vacuum degree of vacuum drying is 0.06-0.08 MPa.

[0029] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0030] 1. Realize the resource utilization of solid waste: Transform viscous solid wastes from multiple industries, such as furfural residue and rubber powder, into high-value, high-adhesion-strength environmentally friendly adhesives, solve the problem of utilizing scraps or solid waste from paper mills, sugar mills, wineries, etc., significantly reduce the environmental pressure caused by solid waste landfill and incineration, turn waste into treasure, and have significant environmental and economic benefits.

[0031] 2. Excellent environmental performance: The preparation process adopts a low-temperature process with low energy consumption; both the activator and crosslinking agent are made of environmentally friendly materials, with no release of harmful gases such as formaldehyde, which is in line with the current development trend of green environmental protection;

[0032] 3. Excellent bonding performance: Through the synergistic effect of composite viscous solid waste and a unique activation and cross-linking process, the viscous components of the solid waste itself are fully activated, and the prepared adhesive has high bonding strength and good water resistance and stability, making it suitable for a variety of scenarios;

[0033] 4. Low cost: The raw materials are widely available solid waste, which is inexpensive; the process is simple and does not require complex equipment, which greatly reduces the preparation cost of the adhesive and makes it highly competitive in the market. Detailed Implementation

[0034] The present invention will be further described below with reference to the embodiments.

[0035] A high-bonding-strength, environmentally friendly adhesive, comprising the following components by weight:

[0036] 60-90 parts of composite viscous solid waste;

[0037] Activator 5-16 parts;

[0038] 2-10 parts of crosslinking agent;

[0039] 10-30 parts water.

[0040] The composite viscous solid waste includes at least three of the following: furfural residue, rubber powder, straw, bagasse, distiller's grains, and starch residue, mixed in any proportion.

[0041] The activator is a composite activator, comprising a biological enzyme preparation and an inorganic weak base, wherein the mass ratio of the biological enzyme preparation to the inorganic weak base is 1:(2-5); the biological enzyme preparation comprises at least one of cellulase, hemicellulase, and amylase, and the inorganic weak base comprises at least one of sodium bicarbonate and potassium carbonate.

[0042] The cross-linking agent is a natural polymer cross-linking agent, including at least one of chitosan, pectin, and konjac flour.

[0043] A method for preparing a high-bonding-strength environmentally friendly adhesive includes the following steps:

[0044] S1: Pretreatment of composite viscous solid waste: Various types of viscous solid waste are crushed, sieved, mixed, and dried to obtain composite viscous solid waste for later use; by crushing and sieving, the particle size of various types of viscous solid waste can be controlled, which can increase the specific surface area, improve the contact efficiency of active components, and reduce the moisture content to avoid moisture interfering with the subsequent activation reaction, thus providing a uniform and stable raw material basis for subsequent activation and cross-linking.

[0045] S2: Low-temperature activation: The pretreated composite viscous solid waste is added to the reactor, along with a composite activator and half water. The mixture is stirred to obtain an activated solid waste slurry. Through the synergistic effect of biological enzymes and inorganic weak bases, the fibrous structure encapsulating the viscous components in the solid waste is destroyed under low-temperature conditions. This exposes active groups such as hydroxyl and carboxyl groups in viscous components such as cellulose, hemicellulose, and starch, activating the activity of viscous components such as cellulose, hemicellulose, and starch. At the same time, the high temperature is avoided from damaging the viscous components, providing reaction sites for subsequent cross-linking reactions.

[0046] S3: Crosslinking modification: Add crosslinking agent and the remaining half of the water to the activated solid waste slurry, stir and react to obtain the modified slurry; adding crosslinking agent to the activated slurry can form an interpenetrating network through the chemical bonding of active groups (hydroxyl, carboxyl groups), so that the dispersed viscous components are polymerized into a continuous binder phase. At the same time, water is added to ensure the uniformity of the system, and stirring promotes the full progress of the crosslinking reaction, ultimately improving the mechanical properties and environmental stability of the adhesive.

[0047] S4: Post-processing: The modified slurry is ground, sieved, impurity removed, dried, and pulverized to obtain a high-strength, environmentally friendly adhesive. By refining the product particle size and controlling the moisture content, the workability and storage stability of the adhesive are ensured.

[0048] The preparation method provided by this invention achieves high-value resource utilization of solid waste by compounding viscous solid wastes from multiple industries, such as furfural residue and rubber powder, combined with environmentally friendly activators and crosslinking agents and low-temperature preparation processes. This not only solves the environmental pressure of landfilling / incineration of solid waste from industries such as papermaking, sugar refining, and brewing, but also significantly reduces the cost of adhesive preparation due to the low cost of solid waste raw materials, simple process, and lack of complex equipment. At the same time, the synergistic effect of the composite solid waste and the unique activation and crosslinking process fully activate the viscous components of the solid waste itself, so that the prepared adhesive has excellent bonding strength, water resistance, and stability. Moreover, the preparation process has low energy consumption and no release of harmful gases such as formaldehyde, resulting in outstanding environmental performance. It can be adapted to multiple application scenarios and has significant environmental benefits, economic benefits, and market competitiveness.

[0049] Example 1

[0050] A method for preparing a high-bonding-strength environmentally friendly adhesive includes the following steps:

[0051] S1: Solid waste pretreatment: Crush 35 parts of furfural residue, 25 parts of straw and 20 parts of starch residue separately, pass them through a 100-mesh sieve, mix them, place the mixture in a hot air drying oven, dry at 70℃ for 2.5h until the moisture content is ≤5%, and obtain composite viscous solid waste for later use.

[0052] S2: Low-temperature activation: Add the pretreated composite viscous solid waste into the reactor, add 1.2 parts of cellulase, 6 parts of sodium bicarbonate and 12.5 parts of water, stir evenly, control the reaction temperature at 50℃, the rotation speed at 180r / min, keep warm and stir for 3.5h to obtain activated solid waste slurry;

[0053] S3: Crosslinking modification: Add 5 parts chitosan and the remaining 12.5 parts water to the activated solid waste slurry, adjust the reaction temperature to 60℃, maintain the rotation speed at 180r / min, and keep stirring for 2.5h.

[0054] S4: Post-processing: The cross-linked modified slurry is ground with a colloid mill for 50 minutes, passed through a 300-mesh sieve, and then vacuum dried at 65℃ and 0.07MPa until the moisture content is ≤6%. After pulverization, a high-strength environmentally friendly adhesive product is obtained.

[0055] Example 2

[0056] A method for preparing a high-bonding-strength environmentally friendly adhesive includes the following steps:

[0057] S1 solid waste pretreatment: Crush 25 parts of rubber powder, 25 parts of sugarcane bagasse and 20 parts of distiller's grains separately, pass them through an 80-mesh sieve, mix them, place the mixture in a hot air drying oven, dry at 60℃ for 3 hours until the moisture content is ≤5%, and obtain composite viscous solid waste for later use.

[0058] S2: Low-temperature activation: Add the pretreated composite viscous solid waste into the reactor, add 1 part hemicellulase, 4 parts potassium carbonate and 10 parts water, stir evenly, control the reaction temperature at 45℃, the rotation speed at 150r / min, keep warm and stir for 4h to obtain activated solid waste slurry.

[0059] S3: Crosslinking modification: Add 4 parts of pectin and the remaining 10 parts of water to the activated solid waste slurry, adjust the reaction temperature to 55℃, keep the rotation speed at 150r / min, and keep the temperature and stir for 3h;

[0060] S4: Post-processing: The cross-linked modified slurry is ground with a colloid mill for 45 minutes, passed through a 280-mesh sieve, and then vacuum dried at 55℃ and 0.06MPa until the moisture content is ≤6%. After pulverization, a high-strength environmentally friendly adhesive product is obtained.

[0061] Example 3

[0062] A method for preparing a high-bonding-strength environmentally friendly adhesive includes the following steps:

[0063] S1: Solid waste pretreatment: Crush 25 parts of furfural residue, 25 parts of rubber powder, 20 parts of straw and 20 parts of sugarcane bagasse separately, pass them through a 120-mesh sieve, mix them, place the mixture in a hot air drying oven, dry at 80℃ for 2 hours until the moisture content is ≤5%, and obtain composite viscous solid waste for later use.

[0064] S2: Low-temperature activation: Add the pretreated composite viscous solid waste into the reactor, add 1.8 parts of amylase, 6.3 parts of sodium bicarbonate, 2.7 parts of potassium carbonate and 15 parts of water, stir evenly, control the reaction temperature at 55℃, the rotation speed at 220r / min, keep warm and stir for 2.5h to obtain activated solid waste slurry;

[0065] S3: Crosslinking modification: Add 6 parts of konjac powder, 4 parts of chitosan and the remaining 15 parts of water to the activated solid waste slurry, adjust the reaction temperature to 65℃, keep the rotation speed at 220r / min, and keep the temperature and stir for 1.5h.

[0066] S4: Post-processing: The cross-linked modified slurry is ground with a colloid mill for 65 minutes, passed through a 320-mesh sieve, and then vacuum dried at 70℃ and 0.08MPa until the moisture content is ≤6%. After pulverization, a high-strength environmentally friendly adhesive product is obtained.

[0067] Comparative test cases

[0068] The three sets of examples were compared with existing commercially available starch adhesives, urea-formaldehyde resin adhesives, and adhesives prepared from single solid waste. Performance tests were conducted on the bonding strength, water resistance, and environmental friendliness of each example. The test results are as follows:

[0069] Example 1: The bonding strength was 3.2 MPa, the water resistance time was 16 h, and the formaldehyde release was not detected;

[0070] Example 2: The bonding strength was 2.6 MPa, the water resistance time was 14 h, and the formaldehyde release was not detected.

[0071] Example 3: The bonding strength was 4.2 MPa, the water resistance time was 19 h, and the formaldehyde release was not detected;

[0072] Commercially available starch adhesive: bonding strength 1.5 MPa, water resistance time 5h, formaldehyde release not detected;

[0073] Commercially available urea-formaldehyde resin adhesive: bond strength 4.0 MPa, water resistance time 20 h, formaldehyde release 0.35 mg / m³. 3 ;

[0074] Adhesive prepared from single furfural residue: bonding strength was 1.8 MPa, water resistance time was 6 h, and formaldehyde release was undetectable.

[0075] Based on the above test comparison results, it can be seen that the adhesive prepared by the present invention using composite viscous solid waste has significant comprehensive performance advantages. Its bonding strength (3.2-4.2MPa) and water resistance time (14-19h) far exceed those of commercially available starch adhesives and adhesives prepared from single furfural residue, and can even be on par with the core performance of commercially available urea-formaldehyde resin adhesives (bonding strength 4.0MPa, water resistance 20h). At the same time, the formaldehyde release of the product of the present invention has never been detected, avoiding the formaldehyde pollution problem of urea-formaldehyde resin adhesives. It has high adhesion, water resistance and environmental protection, and achieves dual optimization of cost and environmental benefits through the resource utilization of solid waste. Its overall performance is better than traditional and single solid waste-based adhesives.

[0076] Finally, it should be noted that the above description is merely a preferred embodiment of the present invention. Those skilled in the art, under the guidance of the present invention, can make various similar representations without departing from the spirit and claims of the present invention, and such modifications all fall within the protection scope of the present invention.

Claims

1. A high-strength, environmentally friendly adhesive, characterized in that: By weight, it includes the following ingredients: 60-90 parts of composite viscous solid waste; Activator 5-16 parts; 2-10 parts of crosslinking agent; 10-30 parts water.

2. The high-bonding-strength environmentally friendly adhesive according to claim 1, characterized in that: The composite viscous solid waste includes at least three of the following: furfural residue, rubber powder, straw, bagasse, distiller's grains, and starch residue, and is mixed in any proportion.

3. The high-bonding-strength environmentally friendly adhesive according to claim 2, characterized in that: The activator is a composite activator, comprising a biological enzyme preparation and an inorganic weak base, wherein the mass ratio of the biological enzyme preparation to the inorganic weak base is 1:(2-5). The biological enzyme preparation includes at least one of cellulase, hemicellulase, and amylase, and the inorganic weak base includes at least one of sodium bicarbonate and potassium carbonate.

4. The high-bonding-strength environmentally friendly adhesive according to claim 3, characterized in that: The crosslinking agent is a natural polymer crosslinking agent, including at least one of chitosan, pectin, and konjac flour.

5. A method for preparing a high-adhesion-strength environmentally friendly adhesive as described in any one of claims 1-4, characterized in that: Includes the following steps: S1: Pretreatment of composite viscous solid waste: Crush, sieve, mix and dry various types of viscous solid waste to obtain composite viscous solid waste for later use; S2: Low-temperature activation: The pretreated composite viscous solid waste is added to the reactor, along with the composite activator and half of the water. The mixture is stirred and reacted to obtain activated solid waste slurry. S3: Crosslinking modification: Add crosslinking agent and the remaining half of the water to the activated solid waste slurry, stir and react to obtain the modified slurry; S4: Post-processing: Grind, sieve, remove impurities, dry, and pulverize the modified slurry to obtain an environmentally friendly adhesive with high bonding strength.

6. The method for preparing a high-bonding-strength environmentally friendly adhesive according to claim 5, characterized in that: In step S1, the various viscous solid wastes that have been crushed are passed through an 80-120 mesh sieve and dried at 60-80℃ for 2-3 hours until the moisture content is ≤5%.

7. The method for preparing a high-adhesion-strength environmentally friendly adhesive according to claim 6, characterized in that: In step S2, the amount of biological enzyme preparation added to the composite activator is 0.5-2% of the weight of the composite viscous solid waste, and the amount of inorganic weak alkali added is 1-10% of the weight of the composite viscous solid waste.

8. The method for preparing a high-adhesion-strength environmentally friendly adhesive according to claim 7, characterized in that: In step S2, the reaction temperature is controlled at 35-55℃, the rotation speed is 100-220r / min, and the temperature is maintained and stirred for 2-4 hours for activation.

9. The method for preparing a high-adhesion-strength environmentally friendly adhesive according to claim 5, characterized in that: In step S3, the reaction temperature is adjusted to 45-65℃, the rotation speed is maintained at 100-220r / min, and the mixture is kept at this temperature and stirred for 1-3 hours. Specifically, when the required bonding strength is ≥3.5MPa, the amount of crosslinking agent added is 7-10 parts, and when the required bonding strength is <3.5MPa, the amount of crosslinking agent added is 2-6 parts.

10. The method for preparing a high-adhesion-strength environmentally friendly adhesive according to claim 9, characterized in that: In step S4, grinding is performed using a colloid mill for 30-65 minutes. The material is then passed through a 200-320 mesh sieve to remove insufficiently activated impurity particles. Finally, it is vacuum dried at 50-70°C until the moisture content is ≤6%. The vacuum degree of vacuum drying is 0.06-0.08 MPa.