Non-isocyanate polyurethane and preparation method thereof

Abstract

In the prior art, the defects of mechanical properties cannot be effectively and synchronously overcome while the reaction activity is improved. The invention provides a preparation method of non-isocyanate polyurethane, which comprises the following steps: carrying out cycloaddition reaction on a compound containing two or more epoxy groups and carbon dioxide under the assistance of a catalyst to obtain a double five-membered cyclic carbonate oligomer; dissolving the double-five-membered cyclic carbonate oligomer in a first solvent, and carrying out a halogenating reagent substitution reaction under the assistance of a free radical initiator to obtain halogenated double-five-membered cyclic carbonate; dissolving the halogenated double five-membered cyclic carbonate in a second solvent, and carrying out ring-opening polymerization reaction on the halogenated double five-membered cyclic carbonate and a diamine compound to obtain non-isocyanate polyurethane of which the main chain contains side group halogen atoms; the preparation method comprises the following steps: adding a di-tertiary amine compound into non-isocyanate polyurethane containing side group halogen atoms, and mixing and reacting to obtain the non-isocyanate polyurethane. A polymerization reaction is activated, and an anchor point of post-crosslinking is also used, so that the two difficulties of reaction activity and mechanical property are overcome at the same time.

Description

Technical Field

[0001] This invention relates to the field of polyurethane materials technology, and in particular to a non-isocyanate polyurethane and its preparation method. Background Technology

[0002] Polyurethane materials have a wide range of applications, but their traditional synthesis relies on highly toxic isocyanates, posing significant risks to human health and the environment. Non-isocyanate polyurethanes (NIPUs) are mainly prepared through the ring-opening reaction of polycyclic carbonates with polyamines, and have attracted considerable attention due to their green and environmentally friendly characteristics. However, this technical route faces two major challenges that severely restrict its industrial application: low reactivity, as the five-membered ring carbonates have weak electrophilicity and react with amines at a much slower rate than traditional isocyanate systems, resulting in slow polymerization; and insufficient mechanical properties, as the existing NIPU main chain structure is relatively simple and lacks effective methods for constructing crosslinking networks. Compared to traditional polyurethanes, which allow for flexible adjustment of hard segments, soft segments, and crosslinking degree, NIPUs often suffer from low strength, low modulus, and poor heat resistance, making it difficult to meet the demands of high-performance applications.

[0003] While some studies have explored introducing electron-withdrawing groups onto cyclic carbonates to enhance reactivity, this modification typically only affects the polymerization stage, offering limited contribution to improving the final polymer's mechanical properties. In other words, existing technologies cannot effectively address the insufficient mechanical properties simultaneously while enhancing reactivity. Achieving a significant leap in the mechanical properties of NIPU materials through green synthesis has become a pressing technical challenge in this field. Summary of the Invention

[0004] This invention addresses the problem that existing technologies cannot effectively solve the problem of insufficient mechanical properties while improving reactivity, and provides a non-isocyanate polyurethane and its preparation method.

[0005] One of the technical solutions of this invention lies in the fundamental and synergistic solution to the two major problems of low reactivity and insufficient mechanical properties in the synthesis of non-isocyanate polyurethanes through the "dual-function" molecular design of halogens. First, by introducing strongly electron-withdrawing halogen atoms into the methylene group of the five-membered ring carbonate, the inductive effect significantly enhances the positive charge of the carbonyl carbon, making nucleophilic attack by the diamine easier to occur, thereby greatly accelerating the ring-opening polymerization rate and overcoming the bottleneck of traditional non-isocyanate polyurethane synthesis requiring high temperature and long reaction time. Second, these halogen atoms are not completely consumed after polymerization activation; some remain on the polymer backbone as side groups, becoming "anchor points" for subsequent crosslinking reactions. When a bis-tertiary amine compound is added, its two tertiary amine groups can undergo nucleophilic substitution reactions with halogens on different molecular chains, forming stable quaternary ammonium salt crosslinking bonds, "stitching" the linear molecular chains into a three-dimensional network structure, thereby significantly improving the crosslinking density, tensile strength, modulus, and heat resistance of the material. In short, the introduced halogen is both an "activator" in the polymerization stage and a "bridge" in the crosslinking stage. Through this integrated design, the improvement of reactivity and the enhancement of mechanical properties are achieved simultaneously. The two complement each other, ultimately resulting in a non-isocyanate polyurethane material that has both rapid curing characteristics and excellent mechanical properties.

[0006] Specifically, S1: A compound containing two or more epoxy groups is cycloaddition reacted with carbon dioxide in a high-pressure reactor with the aid of a catalyst. After the reaction is completed, unreacted CO2 is slowly released to obtain a bis-pentaneous ring carbonate oligomer.

[0007] A schematic diagram of step S1, where R1 is an organic skeleton group selected from: polyol residues, bisphenol residues, epoxidized vegetable oil residues, or any combination of the above groups. S2: Dissolve the bis-pentaneous carbonate obtained in step S1 in an appropriate amount of solvent, and carry out a halogenation reaction with the assistance of a free radical initiator to introduce halogen atoms into the pentaneous carbonate ring, thereby obtaining a halogenated bis-pentaneous carbonate.

[0008] Step S2 illustration: S3: Dissolve the halo-bispentanone carbonate obtained in step S2 in an appropriate amount of the first solvent and react it with a diamine compound to carry out ring-opening polymerization, thereby obtaining a non-isocyanate polyurethane with side halogen atoms in the main chain.

[0009] The schematic diagram of step S3 shows that R2 is a divalent organic group; preferably, R2 is selected from C2-C10 alkylene groups, alicyclic dimethyl groups, or polyether groups; preferably, the C2-C10 alkylene groups are selected from ethylene, propylene, butylene, and hexylene; the alicyclic dimethyl group is isophorone dimethyl group. S4: A tertiary amine compound is added to the non-isocyanate polyurethane containing side-chain halogen atoms obtained in step S3, and the mixture is reacted. The tertiary amine compound undergoes a quaternization substitution reaction with the side-chain halogen atoms on the main chain. The tertiary amine compound acts as a chemical crosslinking point, connecting the molecular chains at both ends to construct a three-dimensional network structure. After post-treatment, the non-isocyanate polyurethane with enhanced mechanical properties is obtained.

[0010] Schematic diagram of step S4 (reactions in steps S1, S2, S3, and S4 proceed sequentially): n represents the number of repeating units, where n is a natural number. R3 represents a divalent organic group; more specifically, R3 is a divalent linking group that can contain an ether bond and connects two tertiary amino groups. R3 is a C2-C10 alkylene group or a C4-C20 alkylene group containing an ether bond. It is a cation.

[0011] Further, the compound containing two or more epoxy groups is one or more of bisphenol A diglycidyl ether, ethylene glycol diglycidyl ether, glycerol triglycidyl ether, or epoxidized soybean oil; the catalyst is one or more of tetrabutylammonium bromide, tetrabutylammonium iodide, benzyltriethylammonium chloride, phenyltrimethylammonium bromide, or bifunctional organoboron catalyst.

[0012] Furthermore, the cycloaddition reaction is carried out at a pressure of 1.2–2 MPa; at a reaction temperature of 100–140 °C; for a reaction time of 6–12 h; and the mass ratio of the compound containing two or more epoxy groups to the catalyst is 100:(1–3).

[0013] Further, the halogenated reagent is one or more of N-chlorosuccinimide, N-bromosuccinimide, and N-iodosuccinimide; the solvent is one or more of carbon tetrachloride, trifluorotoluene, dichloromethane, chloroform, and petroleum ether; and the free radical initiator is one or more of azobisisobutyronitrile, benzoyl peroxide, di-tert-butyl peroxide, and dicumyl peroxide.

[0014] Furthermore, the substitution reaction is carried out under nitrogen protection; the temperature of the substitution reaction is 70-90℃; the time of the substitution reaction is 4-12h; the post-treatment of the substitution reaction is washing, rotary evaporation, and drying; the mass ratio of the bis-pentanone carbonate, free radical initiator, and halogenated reagent is 100:(0.3-1.0):(30-50).

[0015] Further, the diamine is one or more of ethylenediamine, 1,3-propanediamine, 1,4-butanediamine, 1,6-hexanediamine, and isophoronediamine; the first solvent is one or more of N,N-dimethylformamide, N,N-dimethylacetamide, dimethyl sulfoxide, N-methylpyrrolidone, tetrahydrofuran, 1,4-dioxane, and methyl ethyl ketone.

[0016] Furthermore, the ring-opening polymerization reaction is carried out at a temperature of 50–80°C; the ring-opening polymerization reaction is carried out for 2–3 hours; and the mass ratio of the halo-substituted bis-pentane carbonate to the diamine is 100:(15–30).

[0017] Further, the bis-tertiary amine compound is one or more of N,N,N',N'-tetramethylethylenediamine, bis(2-dimethylaminoethyl) ether, N,N,N',N'-tetramethyl-1,4-butanediamine, N,N,N',N'-tetramethyl-1,8-octanediamine, bis(3-dimethylaminopropyl) ether, and bis(2-diethylaminoethyl) ether.

[0018] Furthermore, the temperature of the mixing reaction is 50-60°C; the time of the mixing reaction is 3-6 hours; after the mixing reaction, most of the solvent needs to be evaporated at low temperature first, and then cured at high temperature to obtain the product; the mass ratio of the bis-tertiary amine compound to the bis-tertiary amine compound is 100:(0.5-3).

[0019] Compared with the prior art, the present invention has the following advantages: 1) This invention is a non-isocyanate polyurethane that combines high reactivity and excellent mechanical properties. Through ingenious molecular design, the introduced halogen atoms play a dual role, activating the polymerization reaction and serving as "anchor points" for post-crosslinking, thereby simultaneously overcoming the two major challenges of reactivity and mechanical properties.

[0020] 2) This invention is safe and environmentally friendly: it is not only completely free of highly toxic isocyanates, but also eliminates the hidden danger of residual halogens through quaternization reaction, while giving the material antibacterial properties.

[0021] 3) This invention enables rapid ring-opening polymerization at lower temperatures, avoiding the high temperature and high energy consumption of traditional processes.

[0022] 4) This invention is a non-isocyanate polyurethane that combines high reactivity with excellent mechanical properties, and is suitable for food packaging coatings, marine coatings, wood coatings, and floor coatings. Detailed Implementation

[0023] The following examples are provided to further illustrate the present invention and are intended to explain the invention, not to limit its scope. Unless otherwise specified, all figures are expressed in parts by weight and weight percentages.

[0024] Unless otherwise specified, the raw materials used in this invention are all conventional commercially available products; unless otherwise specified, the methods used in this invention are all conventional methods in the field.

[0025] The embodiments of the present invention will be further described below with reference to several examples.

[0026] Example 1 S1: Take 100 parts of bisphenol A diglycidyl ether and 1 part of tetrabutylammonium bromide, place them in a high-pressure reactor, purge the air with CO2, and pressurize the reactor to a pressure of 1.2 MPa. Heat to 100℃ and stir for 6 hours. After the reaction is complete, cool to obtain bisphenol A type bis-pentanone carbonate.

[0027] S2: Take 100 parts of the product from S1, dissolve it in 300 parts of carbon tetrachloride, add 30 parts of N-chlorosuccinimide and 0.3 parts of azobisisobutyronitrile, purge with nitrogen, and reflux at 70°C for 4 hours. Post-treatment yields chlorobispentanone carbonate.

[0028] S3: Take 100 parts of product S2, dissolve it in 200 parts of N,N-dimethylformamide, heat to 50℃, slowly add 15 parts of hexamethylenediamine, and stir the reaction at 50℃ for 2 hours after the addition is complete to obtain a non-isocyanate polyurethane solution containing side group chlorine atoms.

[0029] S4: Take 100 parts of product S3, add 0.5 parts of N,N,N',N'-tetramethylethylenediamine, stir evenly, pour into a polytetrafluoroethylene mold, cure at 80℃ for 4 hours, cure at 100℃ for 2 hours, and demold naturally to obtain a non-isocyanate polyurethane material.

[0030] Example 2 S1: Take 100 parts of bisphenol A diglycidyl ether and 2 parts of tetrabutylammonium bromide, place them in a high-pressure reactor, charge CO2 to a pressure of 1.6 MPa, heat to 120°C, stir and react for 9 hours to obtain bisphenol A type bis-pentaneous ring carbonate.

[0031] S2: Take 100 parts of product S1, dissolve it in 300 parts of carbon tetrachloride, add 40 parts of N-chlorosuccinimide and 0.65 parts of azobisisobutyronitrile, purge with nitrogen, heat to 80℃ and reflux for 8 hours, and then treat to obtain chlorobispentanone carbonate.

[0032] S3: Take 100 parts of product S2, dissolve it in 200 parts of N,N-dimethylformamide, heat to 65℃, add 22.5 parts of hexamethylenediamine dropwise, and react for 2.5 hours.

[0033] S4: Take 100 parts of product S3, add 1.75 parts of N,N,N',N'-tetramethylethylenediamine, react at 55℃ for 4.5 hours, then cure at 80℃ for 4 hours, and then cure at 100℃ for 2 hours. Demold to obtain the material.

[0034] Example 3 S1: Take 100 parts of bisphenol A diglycidyl ether and 3 parts of tetrabutylammonium bromide, place them in a high-pressure reactor, charge CO2 to a pressure of 2.0 MPa, heat to 140°C, stir and react for 12 hours to obtain bisphenol A type bispentanone carbonate.

[0035] S2: Take 100 parts of product S1, dissolve it in 300 parts of carbon tetrachloride, add 50 parts of N-chlorosuccinimide and 1.0 part of benzoyl peroxide, purge with nitrogen, heat to 90℃ and reflux for 12 hours, and then post-process to obtain chlorobispentanone carbonate.

[0036] S3: Take 100 parts of product S2, dissolve it in 200 parts of N,N-dimethylformamide, heat to 80℃, add 30 parts of hexamethylenediamine, react for 3 hours, and monitor the degree of reaction at amine value: 97%.

[0037] S4: Take 100 parts of product S3, add 3 parts of N,N,N',N'-tetramethylethylenediamine, react at 60℃ for 6 hours, then cure at 80℃ for 4 hours, and then cure at 100℃ for 2 hours. Demold to obtain the material.

[0038] Example 4 S1: Take 100 parts of ethylene glycol diglycidyl ether and 1 part of tetrabutylammonium iodide, add CO2 to a pressure of 1.2 MPa, heat to 100℃, and react for 6 hours to obtain ethylene glycol-type bis-pentaneous ring carbonate.

[0039] S2: Take 100 parts of product S1, dissolve it in 300 parts of trifluorotoluene, add 35 parts of N-bromosuccinimide and 0.5 parts of azobisisobutyronitrile, purge with nitrogen, reflux at 75°C for 6 hours, and then treat to obtain bromobispentanone carbonate.

[0040] S3: Take 100 parts of the product of S2, dissolve it in 200 parts of tetrahydrofuran, heat it to 60℃, add 20 parts of ethylenediamine dropwise, and react for 2.5 hours.

[0041] S4: Take 100 parts of product S3, add 1.5 parts of bis(2-dimethylaminoethyl) ether, react at 55℃ for 4 hours, then cure at 70℃ for 4 hours, and then cure at 90℃ for 2 hours. Demold to obtain the material.

[0042] Example 5 S1: Take 100 parts of glycerol triglycidyl ether and 3 parts of benzyl triethylammonium chloride, add CO2 to a pressure of 2.0 MPa, heat to 140℃, and react for 12 hours to obtain glycerol-type bis-pentaneous ring carbonate.

[0043] S2: Take 100 parts of product S1, dissolve it in 300 parts of dichloromethane, add 45 parts of N-chlorosuccinimide and 0.8 parts of di-tert-butyl peroxide, purge with nitrogen, reflux at 85°C for 10 hours, and then post-process to obtain chlorobispentanone carbonate.

[0044] S3: Take 100 parts of product S2, dissolve it in 200 parts of N,N-dimethylacetamide, heat it to 70℃, add 25 parts of isophorone diamine dropwise, and react for 2.5 hours.

[0045] S4: Take 100 parts of product S3, add 2 parts of N,N,N',N'-tetramethyl-1,4-butanediamine, react at 58℃ for 5 hours, then cure at 80℃ for 4 hours, and then cure at 100℃ for 2 hours. Demold to obtain the material.

[0046] Example 6 S1: Take 100 parts of epoxidized soybean oil and 2 parts of bifunctional organoboron catalyst, charge CO2 to a pressure of 1.8 MPa, heat to 130℃, and react for 10 hours to obtain epoxidized soybean oil-based bis-pentane ring carbonate.

[0047] S2: Take 100 parts of product S1, dissolve it in 300 parts of chloroform, add 30 parts of N-bromosuccinimide and 0.4 parts of benzoyl peroxide, purge with nitrogen, reflux at 70°C for 4 hours, and then proceed with post-treatment to obtain the brominated product.

[0048] S3: Take 100 parts of the product from S2, dissolve it in 200 parts of N-methylpyrrolidone, heat it to 50℃, add 15 parts of 1,6-hexanediamine dropwise, react for 2 hours, and monitor the degree of reaction at 95% based on the amine value.

[0049] S4: Take 100 parts of product S3, add 0.5 parts of bis(3-dimethylaminopropyl) ether, react at 50℃ for 3 hours, then cure at 80℃ for 4 hours, and then cure at 100℃ for 2 hours. Demold to obtain the material.

[0050] Example 7 S1: Take 100 parts of bisphenol A diglycidyl ether and 1 part of phenyltrimethylammonium bromide, add CO2 to a pressure of 1.2 MPa, heat to 100℃, and react for 6 hours to obtain bisphenol A type bis-pentaneous ring carbonate.

[0051] S2: Take 100 parts of product S1, dissolve it in 300 parts of trifluorotoluene, add 35 parts of N-iodosuccinimide and 0.6 parts of azobisisobutyronitrile, purge with nitrogen, reflux at 75°C for 6 hours, and then post-process to obtain the iodinated product.

[0052] S3: Take 100 parts of the product of S2, dissolve it in 200 parts of 1,4-dioxane, heat it to 60℃, add 20 parts of 1,4-butanediamine dropwise, and react for 2 hours.

[0053] S4: Take 100 parts of product S3, add 1.5 parts of N,N,N',N'-tetramethyl-1,8-octanediamine, react at 55℃ for 4 hours, then cure at 80℃ for 4 hours, and then cure at 100℃ for 2 hours. Demold to obtain the material.

[0054] Example 8 S1: Take 100 parts of ethylene glycol diglycidyl ether and 2 parts of tetrabutylammonium bromide, add CO2 to a pressure of 1.5 MPa, heat to 120°C, and react for 8 hours to obtain ethylene glycol-type bis-pentaneous ring carbonate.

[0055] S2: Take 100 parts of product S1, dissolve it in 300 parts of petroleum ether, add 40 parts of N-bromosuccinimide and 0.65 parts of azobisisobutyronitrile, purge with nitrogen, reflux at 80°C for 8 hours, and then treat to obtain the brominated product.

[0056] S3: Take 100 parts of the product from S2, dissolve it in 200 parts of methyl ethyl ketone, heat it to 65℃, add 22.5 parts of 1,3-propanediamine dropwise, and react for 2.5 hours.

[0057] S4: Take 100 parts of product S3, add 1.75 parts of bis(2-diethylaminoethyl) ether, react at 55℃ for 4.5 hours, then cure at 70℃ for 4 hours, and then cure at 90℃ for 2 hours. Demold to obtain the material.

[0058] Comparative Example 1 S1: Take 100 parts of bisphenol A diglycidyl ether and 2 parts of tetrabutylammonium bromide, place them in a high-pressure reactor, charge CO2 to a pressure of 1.6 MPa, heat to 120°C, stir and react for 9 hours to obtain bisphenol A type bis-pentaneous ring carbonate.

[0059] S2: Take 100 parts of product S1, dissolve it in 200 parts of N,N-dimethylformamide, heat to 65℃, add 22.5 parts of hexamethylenediamine, react for 2.5 hours, and then cure the product at 80℃ for 4 hours and at 100℃ for 2 hours. Demold to obtain the material.

[0060] Comparative Example 2 S1: Take 100 parts of bisphenol A diglycidyl ether and 2 parts of tetrabutylammonium bromide, place them in a high-pressure reactor, charge CO2 to a pressure of 1.6 MPa, heat to 120°C, stir and react for 9 hours to obtain bisphenol A type bis-pentaneous ring carbonate.

[0061] S2: Take 100 parts of product S1, dissolve it in 300 parts of carbon tetrachloride, add 40 parts of N-chlorosuccinimide and 0.65 parts of azobisisobutyronitrile, purge with nitrogen, heat to 80℃ and reflux for 8 hours, and then treat to obtain chlorobispentanone carbonate.

[0062] S3: Take 100 parts of product S2, dissolve it in 200 parts of N,N-dimethylformamide, heat to 65℃, add 22.5 parts of hexamethylenediamine, react for 2.5 hours, cure the product at 80℃ for 4 hours, cure at 100℃ for 2 hours, and demold to obtain the material.

[0063] Comparative Example 3 S1: Take 100 parts of bisphenol A diglycidyl ether and 2 parts of tetrabutylammonium bromide, place them in a high-pressure reactor, charge CO2 to a pressure of 1.6 MPa, heat to 120°C, stir and react for 9 hours to obtain bisphenol A type bis-pentaneous ring carbonate.

[0064] S2: Take 100 parts of product S1, dissolve it in 200 parts of N,N-dimethylformamide, heat to 65℃, add 22.5 parts of hexamethylenediamine, react for 2.5 hours, and then cure the product at 80℃ for 4 hours and at 100℃ for 2 hours. Demold to obtain the material.

[0065] S3: Take 100 parts of product S2, add 1.75 parts of N,N,N',N'-tetramethylethylenediamine, react at 55℃ for 4.5 hours, then cure at 80℃ for 4 hours, and then cure at 100℃ for 2 hours. Demold to obtain the material.

[0066] Comparative Example 4 S1: Take 100 parts of bisphenol A diglycidyl ether and 2 parts of tetrabutylammonium bromide, place them in a high-pressure reactor, charge CO2 to a pressure of 1.6 MPa, heat to 120°C, stir and react for 9 hours to obtain bisphenol A type bis-pentaneous ring carbonate.

[0067] S2: Take 100 parts of product S1, dissolve it in 300 parts of carbon tetrachloride, add 30 parts of N-chlorosuccinimide and 0.2 parts of azobisisobutyronitrile, reflux at 80°C for 8 hours under nitrogen protection, and then process to obtain the chlorinated product.

[0068] S3: Take 100 parts of product S2, dissolve it in 200 parts of N,N-dimethylformamide, heat to 65℃, add 22.5 parts of hexamethylenediamine dropwise, and react for 2.5 hours.

[0069] S4: Take 100 parts of product S3, add 1.75 parts of N,N,N',N'-tetramethylethylenediamine, react at 55℃ for 4.5 hours, then cure at 80℃ for 4 hours, and then cure at 100℃ for 2 hours. Demold to obtain the material.

[0070] Comparative Example 5 S1: Take 100 parts of bisphenol A diglycidyl ether and 2 parts of tetrabutylammonium bromide, place them in a high-pressure reactor, charge CO2 to a pressure of 1.6 MPa, heat to 120°C, stir and react for 9 hours to obtain bisphenol A type bis-pentaneous ring carbonate.

[0071] S2: Take 100 parts of product S1, dissolve it in 300 parts of carbon tetrachloride, add 40 parts of N-chlorosuccinimide and 0.65 parts of azobisisobutyronitrile, purge with nitrogen, heat to 80℃ and reflux for 8 hours, and then treat to obtain chlorobispentanone carbonate.

[0072] S3: Take 100 parts of product S2, dissolve it in 200 parts of N,N-dimethylformamide, heat to 65℃, add 22.5 parts of hexamethylenediamine dropwise, and react for 2.5 hours.

[0073] S4: Take 100 parts of product S3, add 0.5 parts of N,N,N',N'-tetramethylethylenediamine, react at 55℃ for 4.5 hours, then cure at 80℃ for 4 hours, and then cure at 100℃ for 2 hours. Demold to obtain the material.

[0074] Amine titration test The degree of reaction was determined by amine titration to assess the degree of ring-opening polymerization in step S3. Approximately 2g of the reaction solution was accurately weighed before and after the reaction. After dissolving in 20mL of anhydrous ethanol, 20.00mL of 0.1mol / L hydrochloric acid standard solution was accurately added to ensure the remaining amine groups reacted completely. Titration with 0.1mol / L sodium hydroxide standard solution using bromophenol blue as an indicator was performed until the solution changed from yellow to blue-purple. The volume consumed was recorded, and a blank experiment was conducted simultaneously. The amine value was calculated using the formula A = [(V0-V1)×c×56.1] / m. The degree of reaction was determined by (A0-A... t Calculated as ) / A0×100%, where A0 is the initial amine value, A t This represents the amine value at the end of the reaction.

[0075] Mechanical property testing The test was performed using a universal testing machine according to the standard GB / T 1040.2-2022. The non-isocyanate polyurethane material obtained in step S4 was made into dumbbell-shaped standard specimens. After being placed in an environment with a temperature of 23℃±2℃ and a relative humidity of 50%±5% for 48 hours for conditioning, the specimens were tested at a tensile speed of 50 mm / min.

[0076] Table 1. Test results of resin reaction degree and mechanical properties in Examples 1-8 and Comparative Examples 1-5. As shown in Table 1, the non-isocyanate polyurethane in this invention, which combines high reactivity and excellent mechanical properties, has good reaction efficiency and mechanical properties.

[0077] It should be understood that the described embodiments are merely some, not all, of the embodiments of the present invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.

[0078] The terminology used in the embodiments of this invention is for the purpose of describing particular embodiments only and is not intended to limit the invention. The singular forms “a,” “the,” and “the” as used in the embodiments of this invention and the appended claims are also intended to include the plural forms unless the context clearly indicates otherwise.

[0079] The above embodiments describe in detail the structure, features, and effects of the present invention. The above description is only a preferred embodiment of the present invention. Any changes made in accordance with the concept of the present invention, or equivalent embodiments modified to have equivalent changes, shall still fall within the scope of protection of the present invention if they do not exceed the scope covered by the specification.

[0080] Although embodiments of the invention have been disclosed for illustrative purposes, those skilled in the art will understand that various substitutions, variations, and modifications are possible without departing from the spirit and scope of the invention and the appended claims. Therefore, the scope of the invention is not limited to the contents disclosed in the embodiments.

Claims

1. A method for preparing a non-isocyanate polyurethane, characterized in that, The method includes the following steps: a compound containing two or more epoxy groups is subjected to a cycloaddition reaction with carbon dioxide under the assistance of a catalyst to obtain a bis-pentanone carbonate oligomer; the bis-pentanone carbonate oligomer is dissolved in a first solvent and subjected to a halogenation reaction under the assistance of a free radical initiator to obtain a halogenated bis-pentanone carbonate; the halogenated bis-pentanone carbonate is dissolved in a second solvent and subjected to a ring-opening polymerization reaction with a diamine compound to obtain a non-isocyanate polyurethane with side halogen atoms in the main chain; a bis-tertiary amine compound is added to the non-isocyanate polyurethane with side halogen atoms in the main chain, and the mixture is reacted to obtain the non-isocyanate polyurethane.

2. The method according to claim 1, characterized in that, The mixing reaction includes a quaternization substitution reaction between the bis-tertiary amine compound and the side halogen atoms on the main chain. The bis-tertiary amine compound acts as a chemical crosslinking point, connecting the two molecular chains to form a three-dimensional network structure. After post-treatment, the non-isocyanate polyurethane with enhanced mechanical properties is obtained.

3. The method according to claim 2, characterized in that, The compound containing two or more epoxy groups is one or more of bisphenol A diglycidyl ether, ethylene glycol diglycidyl ether, glycerol triglycidyl ether, or epoxidized soybean oil; the catalyst is one or more of tetrabutylammonium bromide, tetrabutylammonium iodide, benzyltriethylammonium chloride, phenyltrimethylammonium bromide, or bifunctional organoboron catalyst.

4. The method according to claim 3, characterized in that, The cycloaddition reaction is carried out at a pressure of 1.2–2 MPa, a temperature of 100–140 °C, and a reaction time of 6–12 h. The mass ratio of the compound containing two or more epoxy groups to the catalyst is 100:(1–3).

5. The method according to claim 4, characterized in that, The halogenated reagent is one or more of N-chlorosuccinimide, N-bromosuccinimide, and N-iodosuccinimide; the first solvent is one or more of carbon tetrachloride, trifluorotoluene, dichloromethane, chloroform, and petroleum ether; and the free radical initiator is one or more of azobisisobutyronitrile, benzoyl peroxide, di-tert-butyl peroxide, and dicumyl peroxide.

6. The method according to claim 1, characterized in that, The temperature of the substitution reaction is 70-90℃; the time of the substitution reaction is 4-12h; the substitution reaction is carried out under nitrogen protection; and the mass ratio of the bis-pentaneous carbonate, free radical initiator, and halogenated reagent is 100:(0.3-1.0):(30-50).

7. The method according to claim 6, characterized in that, The diamine compound is one or more selected from ethylenediamine, 1,3-propanediamine, 1,4-butanediamine, 1,6-hexanediamine, and isophoronediamine; the second solvent is one or more selected from N,N-dimethylformamide, N,N-dimethylacetamide, dimethyl sulfoxide, N-methylpyrrolidone, tetrahydrofuran, 1,4-dioxane, and methyl ethyl ketone; the mass ratio of the halo-substituted bis-pentane carbonate to the diamine compound is 100:(15-30); the ring-opening polymerization reaction temperature is 50-80°C; and the ring-opening polymerization reaction time is 2-3 hours.

8. The method according to claim 7, characterized in that, The bis-tertiary amine compound is one or more of N,N,N',N'-tetramethylethylenediamine, bis(2-dimethylaminoethyl) ether, N,N,N',N'-tetramethyl-1,4-butanediamine, N,N,N',N'-tetramethyl-1,8-octanediamine, bis(3-dimethylaminopropyl) ether, and bis(2-diethylaminoethyl) ether.

9. The method according to claim 8, characterized in that, The mass ratio of the non-isocyanate polyurethane containing side-group halogen atoms to the bis-tertiary amine compound is 100:(0.5-3); the mixing reaction temperature is 50-60°C; and the mixing reaction time is 3-6 hours.

10. A method for preparing non-isocyanate polyurethane using any one of claims 1 to 9, characterized in that, The non-isocyanate polyurethane has the following structural formula: Wherein, R1 is an organic skeleton group, which is one or more of polyol residues, bisphenol residues, and epoxidized vegetable oil residues; R2 is a divalent organic group, which is a C2-C10 alkylene group, an alicyclic dimethyl group, or a polyether group; n is the number of repeating units; and R3 is a divalent organic group, which is a C2-C10 alkylene group or a C4-C20 alkylene group containing an ether bond. It is a cation.

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