A bio-based non-isocyanate polyurea material and its preparation method

Abstract

The present invention relates to the field of polymer technology, and more particularly to a kind of bio-based non-isocyanate polyurea material and preparation method thereof, the present invention sequentially reacts guaiacol with epichlorohydrin and carbon dioxide to obtain guaiacol cyclic carbonate, and then heats and polycondenses with a composite curing agent to prepare a bio-based non-isocyanate polyurea material. The present invention has simple synthesis process, and the raw materials guaiacol and β-cyclodextrin are all bio-based, which reduces the consumption of non-renewable resources and is cheap and easy to obtain; the composite curing agent is amino-modified β-cyclodextrin and tris (2-aminoethyl) amine, so that the polyurea material has good mechanical properties. The bio-based non-isocyanate polyurea material prepared by the present invention also has good mechanical properties and thermal stability while utilizing renewable resources, and compared with prior art, has a wide range of applications.

Description

Technical Field

[0001] The present invention relates to the field of polymer technology, and in particular to a bio-based non-isocyanate polyurea material and a preparation method thereof. Background Art

[0002] Polyurethane is a class of polymer materials containing carbamate organic units in its molecular backbone. Polyurea is a special form of polyurethane. A key characteristic of polyurethane (polyurea) is the easy microphase separation of hard and soft segments. By adjusting the structure and ratio of these segments, elastomers or plastics with varying properties can be created. This microphase separation of hard and soft segments gives polyurea exceptional properties not found in other materials. The microphase separation structure formed by urea bonds further surpasses that of carbamate. Its superior properties, such as high mechanical strength, high elongation at break, excellent high and low temperature resistance, flexibility, wet-slip resistance, aging resistance, and corrosion resistance, have led to its widespread application in waterproof and anti-corrosion coatings. Polyurea waterproofing materials are widely used in engineering projects for concrete protection, addressing the problem of spot water seepage. They are also widely used in anti-corrosion coatings for deep-buried pipelines and in automotive component coatings. Their exceptionally high tensile and tear resistance, as well as their high impact strength, make them widely used in structural protection. Their excellent thermal stability has also led to their research and application in thermal insulation materials.

[0003] Traditional polyurea materials are compounds formed by the reaction of isocyanates with amino components, such as through addition polymerization of isocyanates and amine compounds, or using isocyanates and water as raw materials. Patent document CN112679941B, for example, discloses a high-strength, sound-insulating polyurethane-urea composite material. This composite material is formed by spray-molding components A and B onto high-strength fibers. Component A is an isocyanate prepolymer prepared from a polyether polyol, a first chain extender, and a polyisocyanate, with an -NCO content of 15%-20%. Component B is a powdered mixture of an amino-terminated polyether, a polyether polyol, polyurethane microspheres, a coupling agent, a second chain extender, a catalyst, and a water scavenger. This invention not only improves the strength of the polyurethane-urea composite material but also offers excellent sound insulation. However, isocyanates are toxic and pose a health risk.

[0004] In the prior art, some polyurea materials have been improved to address the above-mentioned problems. For example, patent document CN116253876B discloses a non-isocyanate polyurea material, a preparation method, and an application thereof. In this invention, the non-isocyanate polyurea material is prepared using a compound containing aziridine-1-carboxamide and its derivatives as a curing agent and a compound containing a nucleophilic group as a raw material. The polyurea material in this invention has excellent properties of spray polyurea, but the reaction raw material aziridine compound has certain toxicity and the synthesis steps are cumbersome.

[0005] Therefore, according to the above-mentioned related technologies, there is an urgent need to develop a bio-based non-isocyanate polyurea material using renewable resources as raw materials and a preparation method thereof. Summary of the Invention

[0006] In view of this, the purpose of the present invention is to propose a bio-based non-isocyanate polyurea material and a preparation method thereof, so as to solve the problems in the prior art of isocyanate toxicity that easily endangers human health and resource depletion caused by the use of non-renewable resources as raw materials.

[0007] Based on the above objectives, the present invention provides a bio-based non-isocyanate polyurea material and a preparation method thereof, wherein the bio-based non-isocyanate polyurea material is prepared from the following raw materials in parts by weight: 10-20 parts of guaiacol cyclic carbonate and 22-40 parts of a composite curing agent;

[0008] The composite curing agent is obtained by mixing amino-modified beta-cyclodextrin and tris(2-aminoethyl)amine in a molar ratio of 3-4:1.

[0009] Preferably, the preparation method of the guaiacol cyclic carbonate is as follows:

[0010] Step A1. In an argon atmosphere, guaiacol, epichlorohydrin and tetrabutylammonium bromide were added sequentially to a flask and heated under reflux to obtain a mixed solution A;

[0011] Step A2. Sodium hydroxide was added to the mixed solution A, and then heated under reflux to obtain a mixed solution B;

[0012] Step A3. Heat the mixed solution B with carbon dioxide to react to obtain guaiacol cyclic carbonate.

[0013] Preferably, the molar ratio of guaiacol, epichlorohydrin and tetrabutylammonium bromide in step A1 is 1:1.1-1.2:0.08-0.13;

[0014] The temperature during heating under reflux in step A1 is 40-55° C. and the heating time is 2-3 h.

[0015] Preferably, the amount of sodium hydroxide in step A2 is 5-8 mL, and the mass fraction of the sodium hydroxide is 40%;

[0016] The temperature during heating under reflux in step A2 is 40-55° C. and the heating time is 18-20 h.

[0017] Preferably, the molar ratio of the mixed solution B to carbon dioxide in step A3 is 1:1.2-1.3, the temperature during the heating reaction is 115-135° C., and the reaction time is 22-25 h.

[0018] Preferably, the preparation method of the amino-modified β-cyclodextrin is as follows:

[0019] β-cyclodextrin was added to an ethanol aqueous solution and ultrasonically dispersed uniformly. APTES was then added dropwise to the dispersion and heated to reflux. The resulting product was allowed to stand, the supernatant was removed, and the product was washed with ethanol 2-3 times and then dried at 70-80°C for 20-22 hours to obtain amino-modified β-cyclodextrin.

[0020] Preferably, the dosage ratio of the β-cyclodextrin to the ethanol aqueous solution is 0.4-0.5 g: 30-40 mL, the volume ratio of ethanol to water in the ethanol aqueous solution is 13-16: 2-4, and the mass ratio of the β-cyclodextrin to APTES is 1: 2-3.

[0021] Preferably, the frequency of the ultrasonic dispersion is 16-18 kHz, the temperature is 20-30° C., the temperature during the heating reflux is 45-65° C., and the heating time is 11-13 h.

[0022] A method for preparing a bio-based non-isocyanate polyurea material comprises the following steps:

[0023] The guaiacol cyclic carbonate and the composite curing agent are heated to react, and then the temperature is raised to continue the reaction to obtain a bio-based non-isocyanate polyurea material;

[0024] The molar ratio of the guaiacol cyclic carbonate to the composite curing agent is 1:2.2-3.

[0025] Preferably, the temperature during the heating reaction is 90-110° C. and the reaction time is 5.5-7 h;

[0026] The heating temperature is 160-180° C., and the reaction time is 5-6 hours.

[0027] Beneficial effects of the present invention:

[0028] The present invention provides a bio-based non-isocyanate polyurea material and a preparation method thereof. The present invention sequentially reacts guaiacol with epichlorohydrin and carbon dioxide to obtain guaiacol cyclic carbonate, which is then heated and polycondensed with a composite curing agent to prepare the bio-based non-isocyanate polyurea material.

[0029] The present invention features a simple synthesis process. The raw materials, guaiacol and β-cyclodextrin, are both bio-based, reducing the consumption of non-renewable resources and are readily available and inexpensive. The composite curing agent is a mixture of amino-modified β-cyclodextrin and tris(2-aminoethyl)amine. The modified β-cyclodextrin can be used as a bio-based curing agent. The addition of tris(2-aminoethyl)amine enhances the degree of curing, resulting in a polyurea material with excellent mechanical properties. The bio-based, non-isocyanate polyurea material prepared by the present invention utilizes renewable resources while also exhibiting excellent mechanical properties and thermal stability. Compared to existing technologies, it has broad application prospects. DETAILED DESCRIPTION

[0030] In order to make the objectives, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below with reference to specific embodiments.

[0031] The sources and properties of some of the raw materials used in the present invention are as follows:

[0032] Guaiacol was purchased from Shanghai Aladdin Biochemical Technology Co., Ltd.; β-cyclodextrin was purchased from Nanjing Bermuda Biotechnology Co., Ltd.; tris(2-aminoethyl)amine was purchased from Jiangsu Suhang Environmental Protection Engineering Co., Ltd.; epichlorohydrin was purchased from Shandong Yushuo Chemical Co., Ltd.; APTES was purchased from Hangzhou Jessica Chemical Co., Ltd.; tetrabutylammonium bromide was purchased from Jinan Century Tongda Chemical Co., Ltd.; and carbon dioxide was purchased from Huizhou Qianxin Gas Co., Ltd.

[0033] Example 1: A method for preparing a bio-based non-isocyanate polyurea material, comprising the following steps:

[0034] S1. 0.4 g of β-cyclodextrin was added to 30 mL of an ethanol-water solution (wherein the volume ratio of ethanol to water was 13:2). After uniform dispersion under ultrasonication at 20°C and 16 kHz, APTES was dropwise added to the dispersion at a mass ratio of 1:2 between β-cyclodextrin and APTES. The mixture was heated under reflux at 45°C for 13 h. The resulting product was allowed to stand, the supernatant removed, and the product was washed twice with ethanol. The product was then dried at 70°C for 22 h to obtain amino-modified β-cyclodextrin.

[0035] S2. In an argon atmosphere, 1 mol of guaiacol, 1.1 mol of epichlorohydrin, and 0.08 mol of tetrabutylammonium bromide were added to a flask in sequence and heated under reflux at 40 ° C for 3 h to obtain a mixed solution A;

[0036] S3. Add 5 mL of 40% sodium hydroxide to the mixture A, and then heat under reflux at 40°C for 20 h to obtain a mixture B;

[0037] S4. Heating the mixed solution B with carbon dioxide at 115° C. for 25 h, wherein the molar ratio of the mixed solution B to the carbon dioxide is 1:1.2, to obtain guaiacol cyclic carbonate;

[0038] S5. 1 mol of guaiacol cyclocarbonate and 2.2 mol of a composite curing agent, wherein the composite curing agent is a mixture of amino-modified β-cyclodextrin and tris(2-aminoethyl)amine in a molar ratio of 3:1, are heated at 90°C for 7 h. The mixture is then heated to 160°C and reacted for 6 h to obtain a bio-based non-isocyanate polyurea material.

[0039] Example 2: A method for preparing a bio-based non-isocyanate polyurea material, comprising the following steps:

[0040] S1. 0.4 g of β-cyclodextrin was added to 32 mL of an ethanol-water solution (wherein the volume ratio of ethanol to water was 14:2). After uniform dispersion under ultrasonication at 20°C and 16 kHz, APTES was dropwise added to the dispersion at a mass ratio of 1:2 between β-cyclodextrin and APTES. The mixture was heated under reflux at 50°C for 13 h. The resulting product was allowed to stand, the supernatant removed, and the product was washed twice with ethanol. The product was then dried at 70°C for 22 h to obtain amino-modified β-cyclodextrin.

[0041] S2. In an argon atmosphere, 1 mol of guaiacol, 1.1 mol of epichlorohydrin, and 0.09 mol of tetrabutylammonium bromide were added to a flask in sequence and heated under reflux at 45 ° C for 3 h to obtain a mixed solution A;

[0042] S3. Add 6 mL of 40% sodium hydroxide to the mixture A, and then heat under reflux at 45 ° C for 19.5 h to obtain a mixture B;

[0043] S4. Heating the mixed solution B with carbon dioxide at 120° C. for 24 h, wherein the molar ratio of the mixed solution B to the carbon dioxide is 1:1.2, to obtain guaiacol cyclic carbonate;

[0044] S5. 1 mol of guaiacol cyclic carbonate and 2.4 mol of a composite curing agent, wherein the composite curing agent is a mixture of amino-modified β-cyclodextrin and tris(2-aminoethyl)amine in a molar ratio of 3:1, are heated at 95°C for 6.5 h. The mixture is then heated to 165°C and reacted for 6 h to obtain a bio-based non-isocyanate polyurea material.

[0045] Example 3: A method for preparing a bio-based non-isocyanate polyurea material, comprising the following steps:

[0046] S1. 0.45 g of β-cyclodextrin was added to 34 mL of an aqueous ethanol solution (wherein the volume ratio of ethanol to water was 15:3). After uniform dispersion under ultrasonication at 25°C and 17 kHz, APTES was dropwise added to the dispersion at a mass ratio of β-cyclodextrin to APTES of 1:2.5. The mixture was heated under reflux at 55°C for 12 h. The resulting product was allowed to stand, the supernatant removed, and the product was washed twice with ethanol and dried at 75°C for 21 h to obtain amino-modified β-cyclodextrin.

[0047] S2. In an argon atmosphere, 1 mol of guaiacol, 1.15 mol of epichlorohydrin, and 0.1 mol of tetrabutylammonium bromide were added to a flask in sequence and heated under reflux at 50 ° C for 2.5 h to obtain a mixed solution A;

[0048] S3. Add 7 mL of 40% sodium hydroxide to the mixture A, and then heat under reflux at 50°C for 19 h to obtain a mixture B;

[0049] S4. Heating the mixed solution B with carbon dioxide at 125° C. for 24 h, wherein the molar ratio of the mixed solution B to the carbon dioxide is 1:1.25, to obtain guaiacol cyclic carbonate;

[0050] S5. 1 mol of guaiacol cyclic carbonate and 2.6 mol of a composite curing agent, wherein the composite curing agent is a mixture of amino-modified β-cyclodextrin and tris(2-aminoethyl)amine in a molar ratio of 3.5:1, are heated at 100°C for 6 h. The mixture is then heated to 170°C and reacted for 5.5 h to obtain a bio-based non-isocyanate polyurea material.

[0051] Example 4: A method for preparing a bio-based non-isocyanate polyurea material, comprising the following steps:

[0052] S1. 0.45 g of β-cyclodextrin was added to 38 mL of an ethanol-water solution (the volume ratio of ethanol to water was 16:3). After uniform dispersion under ultrasonication at 30°C and 18 kHz, APTES was added dropwise to the dispersion at a mass ratio of β-cyclodextrin to APTES of 1:3. The mixture was heated under reflux at 60°C for 12 h. The resulting product was allowed to stand, the supernatant removed, and the product was washed three times with ethanol. The product was then dried at 80°C for 21 h to obtain amino-modified β-cyclodextrin.

[0053] S2. In an argon atmosphere, 1 mol of guaiacol, 1.2 mol of epichlorohydrin, and 0.12 mol of tetrabutylammonium bromide were added to a flask in sequence and heated under reflux at 50 ° C for 2 h to obtain a mixed solution A;

[0054] S3. Add 8 mL of 40% sodium hydroxide to the mixture A, and then heat under reflux at 50°C for 18.5 h to obtain a mixture B;

[0055] S4. Heating the mixed solution B with carbon dioxide at 130° C. for 23 h, wherein the molar ratio of the mixed solution B to the carbon dioxide is 1:1.3, to obtain guaiacol cyclic carbonate;

[0056] S5. 1 mol of guaiacol cyclocarbonate and 2.8 mol of a composite curing agent, wherein the composite curing agent is a mixture of amino-modified β-cyclodextrin and tris(2-aminoethyl)amine in a molar ratio of 4:1, are heated at 105°C for 5.5 hours. The mixture is then heated to 175°C and reacted for 5 hours to obtain a bio-based non-isocyanate polyurea material.

[0057] Example 5: A method for preparing a bio-based non-isocyanate polyurea material, comprising the following steps:

[0058] S1. 0.5 g of β-cyclodextrin was added to 40 mL of an ethanol-water solution (wherein the volume ratio of ethanol to water was 16:4). After uniform dispersion under ultrasonic conditions at 30°C and 18 kHz, APTES was dropwise added to the dispersion at a mass ratio of β-cyclodextrin to APTES of 1:3. The mixture was heated under reflux at 65°C for 11 h. The resulting product was allowed to stand, the supernatant removed, and the product was washed three times with ethanol. The product was then dried at 80°C for 20 h to obtain amino-modified β-cyclodextrin.

[0059] S2. In an argon atmosphere, 1 mol of guaiacol, 1.2 mol of epichlorohydrin, and 0.13 mol of tetrabutylammonium bromide were added to a flask in sequence and heated under reflux at 55 ° C for 2 h to obtain a mixed solution A;

[0060] S3. 8 mL of 40% sodium hydroxide was added to the mixture A, and then heated under reflux at 55°C for 18 h to obtain a mixture B;

[0061] S4. Heating the mixed solution B with carbon dioxide at 135° C. for 22 h, wherein the molar ratio of the mixed solution B to the carbon dioxide is 1:1.3, to obtain guaiacol cyclic carbonate;

[0062] S5. 1 mol of guaiacol cyclocarbonate and 3 mol of a composite curing agent, wherein the composite curing agent is a mixture of amino-modified β-cyclodextrin and tris(2-aminoethyl)amine in a molar ratio of 4:1, are heated at 110°C for 5.5 hours. The mixture is then heated to 180°C and reacted for 5 hours to obtain a bio-based non-isocyanate polyurea material.

[0063] Comparative Example 1:

[0064] Compared with Example 1, tris(2-aminoethyl)amine was not added during the preparation of the bio-based non-isocyanate polyurea material in this comparative example. The remaining steps and parameters were the same and will not be repeated in this comparative example. Finally, a bio-based non-isocyanate polyurea material was obtained.

[0065] Comparative Example 2:

[0066] Compared with Example 1, this comparative example only adjusts "the composite curing agent is obtained by mixing amino-modified β-cyclodextrin and tris(2-aminoethyl)amine in a molar ratio of 3:1" to "the composite curing agent is obtained by mixing amino-modified β-cyclodextrin and tris(2-aminoethyl)amine in a molar ratio of 1:1". The remaining steps and parameters are the same and will not be repeated in this comparative example. Finally, a bio-based non-isocyanate polyurea material is obtained.

[0067] Comparative Example 3:

[0068] Compared with Example 1, this comparative example only adjusted "1 mol of guaiacol cyclic carbonate and 2.2 mol of composite curing agent heated under reflux" to "1 mol of guaiacol cyclic carbonate and 2 mol of composite curing agent heated under reflux", and the remaining steps and parameters were the same, which will not be repeated in this comparative example. Finally, a bio-based non-isocyanate polyurea material was obtained.

[0069] Comparative Example 4:

[0070] Compared with Example 1, this comparative example only adjusted "1 mol of guaiacol cyclic carbonate and 2.2 mol of composite curing agent heated under reflux" to "1 mol of guaiacol cyclic carbonate and 5 mol of composite curing agent heated under reflux", and the remaining steps and parameters were the same, which will not be repeated in this comparative example. Finally, a bio-based non-isocyanate polyurea material was obtained.

[0071] Performance testing:

[0072] Thermal stability analysis:

[0073] With reference to the ISO11358-2:2021 test standard, a Q50 thermogravimetric analyzer produced by TA Company of the United States was used to test the films made of the bio-based non-isocyanate polyurea materials prepared in Examples 1 to 5 and Comparative Examples 1 to 4. The films were respectively placed in platinum crucibles, and the N2 introduction rate was controlled to be 50 mL / min. The samples were heated from 20°C to 500°C at a rate of 10°C / min. The temperature change rate corresponding to a 5% decrease in sample mass, the temperature change rate corresponding to a 10% decrease in mass, and the residual mass during the heating process were recorded.

[0074] Mechanical properties:

[0075] With reference to GB / T529-2008 standard, 10g of the bio-based non-isocyanate polyurea material prepared in Examples 1-5 and Comparative Examples 1-4 was weighed and poured onto a waxed ceramic plate. The film was scraped twice with 1mm and 2mm thick molds, and the excess coating was scraped off. The coating thickness was controlled at 1.3-1.5mm. The coating was then placed in a standard environment of (23±2)°C and a relative humidity of 65%±15% for 7 days. The AI-7000 tensile testing machine fixture spacing was adjusted to approximately 70mm, and the samples were clamped on the testing machine respectively, keeping the center line of the specimen in the length direction in line with the center of the testing machine fixture. The specimen was stretched to fracture at a tensile speed of (500±5)mm / min. The tensile strength at this time was recorded as the maximum stress, and the elongation at fracture was calculated by the length of the sample before and after fracture.

[0076] Elongation at break calculation formula:

[0077] Elongation at break (%) = (length after breakage - original length) / original length × 100%

[0078] Table 1 Summary of experimental data in Examples 1-5 and Comparative Examples 1-4

[0079]

[0080] Data Analysis:

[0081] As can be seen from Table 1, the bio-based non-isocyanate polyurea material prepared by the present invention has better thermal stability and mechanical properties. This may be due to the good thermal stability of the bio-based materials guaiacol and β-cyclodextrin used in the present invention. The composite curing agent is obtained by mixing amino-modified β-cyclodextrin and tris(2-aminoethyl)amine. The modified β-cyclodextrin can be used as a bio-based curing agent. Tris(2-aminoethyl)amine is a commonly used curing agent for polymer materials. The three amino groups in the molecule have high reactivity and can enhance the degree of curing. The two synergistically enhance the effect during the curing process of the polyurea material, resulting in the prepared bio-based non-isocyanate polyurea material having good mechanical properties.

[0082] In contrast, since tris(2-aminoethyl)amine was not added during the preparation of the bio-based non-isocyanate polyurea material in Comparative Example 1, it can be seen from Table 1 that its thermal stability and mechanical properties are poor. This may be because the activity of the single amino-modified β-cyclodextrin as a curing agent in reacting with guaiacol cyclic carbonate is not high, which affects the curing rate and degree of curing, and thus it is difficult to achieve the expected effect. Therefore, the thermal stability and mechanical properties exhibited by Comparative Example 1 are worse than those of Example 1; in Comparative Example 2, since "the composite curing agent is obtained by mixing amino-modified β-cyclodextrin and tris(2-aminoethyl)amine in a molar ratio of 3:1" is adjusted to "the composite curing agent is obtained by mixing amino-modified β-cyclodextrin and tris(2-aminoethyl)amine in a molar ratio of 1:1", it can be seen from Table 1 that its thermal stability and mechanical properties are poor. This may be because there is too much tris(2-aminoethyl)amine in the composite curing agent, which accelerates the curing rate, reduces the thermal stability of the material during the synthesis process, and is prone to cracking. Therefore, the thermal stability of Comparative Example 2 is poor. The stability and mechanical properties are worse than those in Example 1; in Comparative Example 3, since "1 mol of guaiacol cyclic carbonate and 2.2 mol of composite curing agent are heated and refluxed" is adjusted to "1 mol of guaiacol cyclic carbonate and 2 mol of composite curing agent are heated and refluxed", it can be seen from Table 1 that its thermal stability and mechanical properties are poor. This may be due to the fact that there is too little composite curing agent, the curing and polycondensation speed with guaiacol cyclic carbonate is slow, and the curing is incomplete. Therefore, the thermal stability and mechanical properties exhibited by Comparative Example 3 are worse than those in Example 1; in Comparative Example 4, since "1 mol of guaiacol cyclic carbonate and 2.2 mol of composite curing agent are heated and refluxed" is adjusted to "1 mol of guaiacol cyclic carbonate and 5 mol of composite curing agent are heated and refluxed", it can be seen from Table 1 that its thermal stability and mechanical properties are poor. This may be due to the fact that there is too much composite curing agent, the curing agent molecules are easily agglomerated during the curing process, and it is difficult to combine with the reactants to play a role. Therefore, the thermal stability and mechanical properties exhibited by Comparative Example 4 are worse than those in Example 1.

[0083] Those skilled in the art should understand that the discussion of any of the above embodiments is merely illustrative and is not intended to imply that the scope of the present invention is limited to these examples. Within the scope of the present invention, the technical features in the above embodiments or different embodiments may be combined, the steps may be implemented in any order, and there are many other variations of the different aspects of the present invention as described above, which are not provided in detail for the sake of simplicity.

[0084] The present invention is intended to cover all such substitutions, modifications and variations that fall within the broad scope of the appended claims. Therefore, any omissions, modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A bio-based non-isocyanate polyurea material, characterized in that: It is prepared from the following raw materials in parts by weight: 10-20 parts of guaiacol cyclic carbonate, 22-40 parts of composite curing agent; The composite curing agent is obtained by mixing amino-modified β-cyclodextrin and tris(2-aminoethyl)amine in a molar ratio of 3-4:1; The preparation method of the guaiacol cyclic carbonate is as follows: Step A1. In an argon atmosphere, guaiacol, epichlorohydrin and tetrabutylammonium bromide were added sequentially to a flask and heated under reflux to obtain a mixed solution A; Step A2. Sodium hydroxide was added to the mixed solution A, and then heated under reflux to obtain a mixed solution B; Step A3. Heat the mixed solution B with carbon dioxide to react to obtain guaiacol cyclic carbonate.

2. The bio-based non-isocyanate polyurea material according to claim 1, characterized in that: The molar ratio of guaiacol, epichlorohydrin and tetrabutylammonium bromide in step A1 is 1:1.1-1.2:0.08-0.13; The temperature during heating under reflux in step A1 is 40-55° C. and the heating time is 2-3 h.

3. The bio-based non-isocyanate polyurea material according to claim 1, characterized in that: In step A2, the amount of sodium hydroxide is 5-8 mL, and the mass fraction of the sodium hydroxide is 40%; The temperature during heating under reflux in step A2 is 40-55° C. and the heating time is 18-20 h.

4. The bio-based non-isocyanate polyurea material according to claim 1, characterized in that: In step A3, the molar ratio of the mixed solution B to carbon dioxide is 1:1.2-1.3, the temperature during the heating reaction is 115-135° C., and the reaction time is 22-25 h.

5. The bio-based non-isocyanate polyurea material according to claim 1, characterized in that: The preparation method of the amino-modified β-cyclodextrin is as follows: β-cyclodextrin was added to an ethanol aqueous solution and ultrasonically dispersed uniformly. APTES was then added dropwise to the dispersion and heated to reflux. The resulting product was allowed to stand, the supernatant was removed, and the product was washed with ethanol 2-3 times and then dried at 70-80°C for 20-22 hours to obtain amino-modified β-cyclodextrin.

6. The bio-based non-isocyanate polyurea material according to claim 5, characterized in that: The dosage ratio of the β-cyclodextrin to the ethanol aqueous solution is 0.4-0.5 g: 30-40 mL, the volume ratio of ethanol to water in the ethanol aqueous solution is 13-16: 2-4, and the mass ratio of the β-cyclodextrin to APTES is 1: 2-3.

7. The bio-based non-isocyanate polyurea material according to claim 5, characterized in that: The frequency of the ultrasonic dispersion is 16-18 kHz and the temperature is 20-30° C., the temperature during the heating reflux is 45-65° C. and the heating time is 11-13 h.

8. A method for preparing the bio-based non-isocyanate polyurea material according to any one of claims 1 to 7, characterized in that: The following steps are involved: The guaiacol cyclic carbonate and the composite curing agent are heated to react, and then the temperature is raised to continue the reaction to obtain a bio-based non-isocyanate polyurea material; The molar ratio of the guaiacol cyclic carbonate to the composite curing agent is 1:2.2-3.

9. The method for preparing the bio-based non-isocyanate polyurea material according to claim 8, characterized in that: The temperature during the heating reaction is 90-110° C. and the reaction time is 5.5-7 hours; The heating temperature is 160-180° C., and the reaction time is 5-6 hours.

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