Bio-based non-isocyanate polyurea material and preparation method thereof

Abstract

The invention relates to the technical field of macromolecules, in particular to a bio-based non-isocyanate polyurea material and a preparation method thereof.The preparation method comprises the steps that guaiacol sequentially reacts with epoxy chloropropane and carbon dioxide to obtain guaiacol cyclic carbonate, and then the guaiacol cyclic carbonate and a composite curing agent are heated and subjected to polycondensation to prepare the bio-based non-isocyanate polyurea material. The synthesis process is simple and convenient, the used raw materials guaiacol and beta-cyclodextrin are bio-based, consumption of non-renewable resources is reduced, and the raw materials are low in price and easy to obtain; the composite curing agent is obtained by mixing amino-modified beta-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 preparation method disclosed by the invention has good mechanical properties and thermal stability while renewable resources are utilized, and has a wide application prospect compared with the prior art.

Description

Technical Field

[0001] The 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 type of polymer material containing carbamate organic units in the main chain of the molecule, and polyurea material is a special form of polyurethane material. The biggest feature of polyurethane (polyurea) is that the hard segment and the soft segment are easy to form microphase separation, and elastomers or plastics with different properties can be obtained by adjusting the structure and ratio of the hard and soft segments. Polyurea has excellent properties that other materials do not have due to the microphase separation structure of the hard segment and the soft segment, and the microphase separation structure formed by the urea bond is further superior to the microphase separation result formed by carbamate. Its performance is more excellent, such as high mechanical strength, high elongation at break, good high and low temperature resistance, flexibility, anti-slip, aging resistance, and anti-corrosion. Characteristics make polyurea materials widely used in the field of waterproof and anti-corrosion coatings. In engineering, polyurea waterproof materials are widely used for concrete protection to solve the problem of point seepage; they are also widely used in anti-corrosion coatings for deep underground pipelines and coatings of automotive parts. The ultra-high tensile and tear resistance, as well as the extremely high impact strength, make it widely used in the field of structural protection; good thermal stability also makes it have certain research and application in the field of thermal insulation materials.

[0003] Traditional polyurea materials are a class of compounds generated by the reaction of isocyanate and amino components, such as the addition polymerization reaction of isocyanate and amine compounds, or the preparation of isocyanate and water as raw materials. For example, the patent technology document CN112679941B discloses a high-strength sound-insulating polyurethane urea composite material, which is formed by spraying and compounding component A and component B with high-strength fiber; the component A is an isocyanate prepolymer prepared from polyether polyol, a first chain extender and polyisocyanate, and the -NCO content is 15%-20%; the component B is a mixture powder of terminal amino polyether, polyether polyol, polyurethane microspheres, coupling agent, second chain extender, catalyst and dehydrating agent. This invention not only improves the strength of the polyurethane urea composite material, but also has excellent sound insulation performance, but isocyanate has certain toxicity and is easy to cause harm to people's health.

[0004] In the prior art, some polyurea materials have been improved for the above-mentioned problems. For example, patent document CN116253876B discloses a non-isocyanate polyurea material and its preparation method and application. In the invention, the non-isocyanate polyurea material is prepared by using aziridine-1-carboxamide-containing compounds and their derivatives as curing agents and nucleophilic group-containing compounds as raw materials. The polyurea material in the 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 provide a bio-based non-isocyanate polyurea material and a preparation method thereof, so as to solve the problem of isocyanate toxicity that easily harms human health and the problem of resource depletion caused by the use of non-renewable resources as raw materials in the prior art.

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

[0008] The composite curing agent is obtained by mixing amino-modified beta-cyclodextrin and tri(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 are sequentially added to a flask, and the mixture is heated under reflux to obtain a mixed solution A;

[0011] Step A2. Add sodium hydroxide to the mixed solution A, and then heat under reflux to obtain a mixed solution B;

[0012] Step A3: heating the mixed solution B and 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 and 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 and reflux in step A2 is 40-55° C. and the heating time is 18-20 h.

[0017] Preferably, 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.

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

[0019] Add β-cyclodextrin to an ethanol aqueous solution, disperse it evenly by ultrasonication, then add APTES dropwise to the dispersion, heat to reflux, let the resulting product stand, remove the supernatant, wash with ethanol 2-3 times, and then dry at 70-80°C for 20-22h 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 heating and 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, so as 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 invention provides a bio-based non-isocyanate polyurea material and a preparation method thereof. The 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 the bio-based non-isocyanate polyurea material.

[0029] The synthesis process of the present invention is simple, and the raw materials guaiacol and β-cyclodextrin used are both bio-based, which reduces the consumption of non-renewable resources and is cheap and easy to obtain; the composite curing agent is obtained by mixing amino-modified β-cyclodextrin and tris(2-aminoethyl)amine, and the β-cyclodextrin can be used as a bio-based curing agent after modification, and tris(2-aminoethyl)amine is added to enhance the degree of curing, so that the polyurea material has good mechanical properties. The bio-based non-isocyanate polyurea material prepared by the present invention not only utilizes renewable resources, but also has good mechanical properties and thermal stability, and has a wide range of application prospects compared with the prior art. 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 in conjunction with 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.; tri(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.; 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 ethanol-water solution, wherein the volume ratio of ethanol to water in the ethanol-water solution was 13:2, and after being uniformly dispersed at 20°C and 16 kHz ultrasonic frequency, APTES was added dropwise to the dispersion, and the mass ratio of β-cyclodextrin to APTES was 1:2. The mixture was heated under reflux at 45°C for 13 h, the obtained product was allowed to stand, the supernatant was removed, the mixture was washed twice with ethanol, and 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 the mixture was 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 mixed solution A, and then heat and reflux at 40°C for 20 h to obtain a mixed solution B;

[0037] S4. heating the mixed solution B and 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 are heated at 90°C for 7 hours, wherein the composite curing agent is a mixture of amino-modified β-cyclodextrin and tri(2-aminoethyl)amine in a molar ratio of 3:1, and then the temperature is raised to 160°C and the reaction is continued for 6 hours 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 ethanol-water solution, wherein the volume ratio of ethanol to water in the ethanol-water solution was 14:2, and after being uniformly dispersed at 20°C and 16 kHz ultrasonic frequency, APTES was added dropwise to the dispersion, and the mass ratio of β-cyclodextrin to APTES was 1:2. The mixture was heated under reflux at 50°C for 13 h, and the obtained product was allowed to stand, the supernatant was removed, and the mixture was washed twice with ethanol, and 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 the mixture was 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 mixed solution A, and then heat and reflux at 45° C. for 19.5 h to obtain a mixed solution B;

[0043] S4. heating the mixed solution B and 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 are heated at 95°C for 6.5 hours, wherein the composite curing agent is a mixture of amino-modified β-cyclodextrin and tri(2-aminoethyl)amine in a molar ratio of 3:1, and then the temperature is raised to 165°C and the reaction is continued for 6 hours 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 ethanol-water solution, wherein the volume ratio of ethanol to water in the ethanol-water solution was 15:3, and after being uniformly dispersed at 25°C and an ultrasonic frequency of 17 kHz, APTES was added dropwise to the dispersion, and the mass ratio of β-cyclodextrin to APTES was 1:2.5. The dispersion was heated under reflux at 55°C for 12 h, and the obtained product was allowed to stand, the supernatant was removed, and the product was washed twice with ethanol, and then 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 the mixture was 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 mixed solution A, and then heat under reflux at 50° C. for 19 h to obtain a mixed solution B;

[0049] S4. heating the mixed solution B and 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 cyclocarbonate and 2.6 mol of a composite curing agent are heated at 100°C for 6 hours, wherein the composite curing agent is a mixture of amino-modified β-cyclodextrin and tri(2-aminoethyl)amine in a molar ratio of 3.5:1, and then the temperature is raised to 170°C and the reaction is continued for 5.5 hours 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 ethanol-water solution, wherein the volume ratio of ethanol to water in the ethanol-water solution was 16:3, and after being uniformly dispersed at 30°C and an ultrasonic frequency of 18 kHz, APTES was added dropwise to the dispersion, and the mass ratio of β-cyclodextrin to APTES was 1:3. The mixture was heated under reflux at 60°C for 12 h, and the obtained product was allowed to stand, the supernatant was removed, and the mixture was washed with ethanol for 3 times, and 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 the mixture was 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 mixed solution A, and then heat and reflux at 50° C. for 18.5 h to obtain a mixed solution B;

[0055] S4. heating the mixed solution B and 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 are heated at 105°C for 5.5 hours, wherein the composite curing agent is a mixture of amino-modified β-cyclodextrin and tri(2-aminoethyl)amine in a molar ratio of 4:1, and then the temperature is raised to 175°C and the reaction is continued 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 ethanol-water solution, wherein the volume ratio of ethanol to water in the ethanol-water solution was 16:4, and after being uniformly dispersed at 30°C and an ultrasonic frequency of 18 kHz, APTES was added dropwise to the dispersion, and the mass ratio of β-cyclodextrin to APTES was 1:3. The dispersion was heated under reflux at 65°C for 11 h, and the obtained product was allowed to stand, the supernatant was removed, and the product was washed with ethanol for 3 times, and 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 the mixture was heated under reflux at 55° C. for 2 h to obtain a mixed solution A;

[0060] S3. Add 8 mL of 40% sodium hydroxide to the mixed solution A, and then heat and reflux at 55° C. for 18 h to obtain a mixed solution B;

[0061] S4. heating the mixed solution B and 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 are heated at 110°C for 5.5 hours, wherein the composite curing agent is a mixture of amino-modified β-cyclodextrin and tri(2-aminoethyl)amine in a molar ratio of 4:1, and then the temperature is raised to 180°C and the reaction is continued 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 amino-modified β-cyclodextrin and tri(2-aminoethyl)amine mixed in a molar ratio of 3:1" to "the composite curing agent is amino-modified β-cyclodextrin and tri(2-aminoethyl)amine mixed in a molar ratio of 1:1", and the remaining steps and parameters are the same, which will not be repeated in this comparative example, and finally a bio-based non-isocyanate polyurea material is obtained.

[0067] Comparative Example 3:

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

[0069] Comparative Example 4:

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

[0071] Performance Testing:

[0072] Thermal stability analysis:

[0073] Referring to the ISO11358-2:2021 test standard, the 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 placed in platinum crucibles respectively, and the N2 introduction rate was controlled to be 50 mL / min. The films 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 were recorded during the heating process.

[0074] Mechanical properties:

[0075] Referring to GB / T529-2008 standard, weigh 10g of the bio-based non-isocyanate polyurea material prepared in Example 1-Example 5 and Comparative Example 1-Comparative Example 4 and pour it on a waxed ceramic plate, use 1mm and 2mm thick molds to scrape and apply the film twice, and scrape off the excess coating, and control the coating thickness to 1.3-1.5mm. Then place the coating in a standard environment of (23±2)℃ and relative humidity of 65%±15% for 7d. Adjust the clamp spacing of the AI-7000 tensile testing machine to about 70mm, clamp the samples on the testing machine respectively, keep the center line of the length direction of the specimen on the same line with the center of the testing machine clamp, and stretch it to break at a stretching speed of (500±5)mm / min, record the tensile strength at this time as the maximum stress, and calculate the elongation at break by the length of the sample before and after the fracture.

[0076] Elongation at break calculation formula:

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

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

[0079]

[0080] Data Analysis:

[0081] It can be seen from Table 1 that the bio-based non-isocyanate polyurea material prepared by the present invention has better thermal stability and mechanical properties, which 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, and the β-cyclodextrin can be used as a bio-based curing agent after modification. Tris(2-aminoethyl)amine is a commonly used curing agent for polymer materials. The molecule contains three amino groups with high reactivity and can enhance the degree of curing. The two synergize in the curing process of the polyurea material, so that the prepared bio-based non-isocyanate polyurea material has 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 single amino-modified β-cyclodextrin is not very active in reacting with guaiacol cyclic carbonate as a curing agent, 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 and mechanical properties exhibited by Comparative Example 2 are 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, which 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, so 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, which 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, so 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. Under the concept 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 in 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 beta-cyclodextrin and tri(2-aminoethyl)amine in a molar ratio of 3-4:

1.

2. The bio-based non-isocyanate polyurea material according to claim 1, characterized in that: The preparation method of the guaiacol cyclic carbonate is as follows: Step A1. In an argon atmosphere, guaiacol, epichlorohydrin and tetrabutylammonium bromide are sequentially added to a flask, and the mixture is heated under reflux to obtain a mixed solution A; Step A2. Add sodium hydroxide to the mixed solution A, and then heat under reflux to obtain a mixed solution B; Step A3: heating the mixed solution B and carbon dioxide to react to obtain guaiacol cyclic carbonate.

3. The bio-based non-isocyanate polyurea material according to claim 2, 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 and reflux in step A1 is 40-55° C. and the heating time is 2-3 h.

4. The bio-based non-isocyanate polyurea material according to claim 2, 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 and reflux in step A2 is 40-55° C. and the heating time is 18-20 h.

5. The bio-based non-isocyanate polyurea material according to claim 2, 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 hours.

6. 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: Add β-cyclodextrin to an ethanol aqueous solution, disperse it evenly by ultrasonication, then add APTES dropwise to the dispersion, heat to reflux, let the resulting product stand, remove the supernatant, wash with ethanol 2-3 times, and then dry at 70-80°C for 20-22h to obtain amino-modified β-cyclodextrin.

7. The bio-based non-isocyanate polyurea material according to claim 6, 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.

8. The bio-based non-isocyanate polyurea material according to claim 6, 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.

9. A method for preparing the bio-based non-isocyanate polyurea material according to any one of claims 1 to 8, 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, so as 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.

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

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