Glycine-based polyurethane and preparation method thereof

Abstract

The invention discloses glycine-based polyurethane and a preparation method thereof, the structural formula of the glycine-based polyurethane is as shown in formula I. The preparation method of the glycine-based polyurethane comprises the step of reacting an organic catalyst, a solvent, an initiator and a glycine-based lactone monomer. Compared with the existing aliphatic polyurethane high polymer material, the glycine-based polyurethane provided by the invention enriches the multifunctionality of the material, improves the application value and expands the application field. And meanwhile, the prepared glycine-based polyurethane has recoverability. And secondly, the preparation method of the glycine-based polyurethane is simple to operate, strong in controllability and high in product yield, and various transformations can be generated subsequently.

Description

Technical Field

[0001] The present invention relates to the field of polymer synthesis chemistry, and in particular to a glycine-based polyamino ester and a preparation method thereof. Background Art

[0002] Polyurethanes (PAEs) have attracted considerable attention due to their excellent biocompatibility and biodegradability, diverse functionalization, and customizable modifications of the backbone or side chains. Their potential applications in the biomedical field are rapidly increasing, particularly in gene delivery, drug delivery, and bioimaging. PAEs are promising biodegradable, non-viral polymer carriers for gene delivery. They contain biodegradable ester groups (hydrolysis of the ester bonds in the polymer backbone increases their biodegradability and biocompatibility). PAEs possess tertiary amine groups in their backbones with a pKa of approximately 6.5, similar to the pH of the cancer cell environment. When drug-loaded PAE nanoparticles are placed at a pH below 6.5, the PAEs become protonated, resulting in a positively charged surface, enhancing interactions between the nanoparticles and cancer cells and leading to cellular internalization. Furthermore, protonated PAEs exhibit hydrophilicity in the more acidic endosome and lysosomal environments of cancer cells. This protonation process imparts a hydrophobic-to-hydrophilic transition to PAE-based nanoparticles, leading to rapid drug release and improved therapeutic efficacy. It is feasible to further adjust the drug release profile by introducing additional functional groups and copolymerizing with other polymers. In recent years, some teams have found that hyperbranched or dendritic polyurethanes exhibit intrinsic blue / green fluorescence behavior even in the absence of conventional luminophores. This is because polyurethanes contain electron-rich heteroatom groups, including amines, amides, and esters, and their hyperbranched structures promote the formation of electron delocalization and spatial conjugation (TSC). In addition, the fluorescence properties of polyurethanes can be adjusted by changing the molecular weight, chemical structure, topology, etc. The biodegradability, biocompatibility, and lack of aggregation-induced quenching of polyurethanes show great potential in the application of fluorescent probes.

[0003] The synthesis methods of amino esters can be mainly divided into two categories. The first category is the two-step polymerization method, that is, the synthesis is carried out by step-growth polymerization, which mainly includes Michael addition polymerization (MAP), polycondensation (PCD) and spontaneous copolymerization of cyclic imino ethers or aziridines with zwitterions (SZWIP); the second category is chain growth polymerization, such as the ring-opening polymerization (ROP) of azalactones. Michael addition polymerization has the following advantages: the starting materials are cheap and commercially available; the polymerization can be synthesized in one step and no by-products are produced during the polymerization process; the structure of the prepared polyamino esters is diverse; however, MAP usually requires a reaction temperature of 60-90°C for 20-72 hours to ensure successful polymerization, and the dispersion is usually relatively wide (D M>1.3). Condensation polymerization is a traditional and widely used step-growth polymerization reaction. The monomers required are readily available, and the operation is mature and reliable. However, it also has inherent disadvantages, such as the production of numerous byproducts, high reaction temperatures and times, and a wide molecular weight distribution of the resulting polymer. Spontaneous zwitterionic copolymerization (SZWIP) requires no initiator or catalyst, but proceeds via nucleophilic (MN) and electrophilic (ME) monomers via a zwitterionic intermediate. The zwitterionic intermediates formed by SZWIP can react with each other through their complementary end groups to form dimeric zwitterions. Subsequently, as the growth process continues, larger zwitterions of higher molecular weight are gradually formed, ultimately yielding the corresponding polymer through termination reactions. Research has shown that the alternating properties of the copolymer are significantly influenced by the reaction solvent. Ring-opening polymerization (ROP) allows for excellent polymerization control under mild conditions, resulting in polymers with well-defined chemical structures and target molecular weights, as well as narrow dispersities.

[0004] Currently, the main methods for preparing polyurethanes by ring-opening polymerization (ROP) include: preparing polyurethanes by ROP from azacaprolactone and preparing polyurethanes by ROP from azavalerolactone. The main problem is that they use petroleum-based raw materials and are non-recyclable. This patent uses bio-based glycine as a raw material to prepare azalactone monomers, and then prepares polyurethanes by ring-opening polymerization. The obtained polyurethanes can be completely depolymerized to monomers, exhibiting a "monomer-polymer-monomer" closed-loop cycle, which helps achieve a circular materials economy. Summary of the Invention

[0005] Purpose of the invention: The technical problem to be solved by the present invention is to provide a glycine-based azalactone, a bio-based polyurethane prepared therefrom and a preparation method thereof in view of the shortcomings of the prior art.

[0006] In order to solve the above technical problems, the present invention discloses the following technical solutions:

[0007] At room temperature (25°C), glycine (7.507 g, 100 mmol, 1 equiv) and sodium hydroxide (3.997 g, 100 mol, 1 equiv) were added to a 50 mL pressure bottle. Water was added and stirred until the glycine and sodium hydroxide dissolved. Epoxide (100 mmol, 1 equiv) was then added dropwise to the pressure bottle. The reaction was allowed to react at room temperature (25°C) for 24 h. After the reaction, hydrochloric acid was added to adjust the pH to 5-6. The solution was then rotary evaporated, concentrated, and vacuum-evacuated to yield a white solid. This solid was used directly in the next step without further purification.

[0008] The product from the previous step, 4-dimethylaminopyridine (DMAP) (0.611 g, 25 mmol, 0.05 equiv), was added to 150 mL of dichloromethane (DCM) at 0°C and stirred to dissolve. Di-tert-butyl dicarbonate (23 mL, 110 mmol, 1.1 equiv) was then added dropwise. The mixture was allowed to react at 0°C for 10 min and then at room temperature for 24 h. After completion of the reaction, the mixture was concentrated by rotary evaporation. The intermediate product was diluted with a suitable amount of ethyl acetate (EA) and washed twice with distilled water and once with saturated brine. The organic phase was dried over anhydrous magnesium sulfate, filtered, and rotary evaporated to yield a yellow liquid. Purification by column chromatography (PE:EA = 40:1 to 8:1) afforded the colorless, transparent glycine-based azalide (yield 20-50%).

[0009] In a first aspect, the present invention discloses a glycine-based polyamino ester, the general formula of which is shown in Formula I:

[0010]

[0011] in,

[0012] The general structure of Y is shown in Formula IV:

[0013]

[0014] n is any integer selected from 10 to 2000;

[0015] The number average molecular weight of the glycine polyurethane is 2000 to 400000 g mol -1 , n is selected from any integer between 10 and 3000 so that the number average molecular weight of the glycine-based polyurethane is 2000 to 400000 g mol -1 ;

[0016] The dispersion coefficient of the glycine-based polyurethane is 1.02-1.25, such as 1.16, 1.19, and 1.21.

[0017] In some embodiments, the glycine-based polyamino ester is any one of Formula I;

[0018]

[0019] In a second aspect, the present invention discloses a method for preparing the above polymer.

[0020] The method comprises the following steps: reacting the catalysts, solvents, initiators represented by formula IV and formula V with the glycine lactone represented by formula II; further, the method comprises the following steps: stirring the catalysts, solvents, and initiators represented by formula IV and formula V for 1-8 minutes, and then adding the glycine lactone represented by formula II for reaction; further, the method comprises the following steps: stirring the catalysts, solvents, and initiators represented by formula IV and formula V for 3-6 minutes, and then adding the glycine lactone represented by formula II for reaction.

[0021] In some embodiments, the method includes the following steps: stirring the catalyst, solvent, and initiator represented by Formula IV and Formula V at 0-100°C for 3-6 minutes, then adding the solution of glycine lactone represented by Formula II and the second solvent and continuing to stir and react at 0-100°C for 5 minutes to 24 hours; the first solvent and the second solvent are the same solvent; in some embodiments, the molar volume ratio of the glycine lactone represented by Formula II to the first solvent and the second solvent is 1-5 mol / L, preferably 3.14 mol / L.

[0022] The catalyst includes 1,5,7-triazabicyclo[4.4.0]dec-5-ene (TBD), 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU), and 1,3-dimesityl imidazole-2-ylidene (IMes).

[0023] Wherein, the reaction solvent is one of toluene, tetrahydrofuran, dichloromethane and N,N-dimethylformamide.

[0024] Wherein, the initiator is an alcohol; preferably, the initiator is methanol, ethanol, isopropanol, tert-butanol, benzyl alcohol, phenylethyl alcohol, phenylpropanol, diphenylmethanol, 2,2-diphenylethanol.

[0025] The structural formula of the glycine lactone shown in Formula II is as follows:

[0026]

[0027] The general structural formula of epoxide is shown in Formula III:

[0028]

[0029] Wherein, the molar ratio of the glycine lactone represented by formula II, the catalyst represented by formula V and the initiator represented by formula IV is 10-3000:1-20:1-20:1, such as 30-50:1:1:1, such as 100-300:1:1:1, such as 500:2:2:1, such as 55:9:9:1, such as 1000-200:10-20:10-20:1.

[0030] Wherein, the reaction temperature is 0-100° C.; and the reaction time is 5-1440 min.

[0031] In a third aspect, the present invention discloses the use of the glycine-based polyamino ester described in the first aspect or the glycine-based polyamino ester prepared by the method described in the second aspect in the preparation of chemically recyclable materials.

[0032] The glycine-based polyurethane prepared by the present invention can be rapidly depolymerized to monomers under certain conditions, has a purity of 99%, and has good recyclability. The degradation conditions are: the catalyst is 1,5,7-triazabicyclo[4.4.0]dec-5-ene (TBD) (1 to 10 mol% of the polymer), the reaction temperature is 60 to 120°C, toluene is used as the solvent (polymer concentration is 0.3 to 0.7 g / mL), the reaction time is 1 to 60 minutes, and the recovery rate is 60 to 99%.

[0033] Beneficial effects:

[0034] (1) The raw materials are bio-based, the monomer synthesis method is simple, the monomer types are rich and the structure is highly adjustable. The glycine-based polyurethane synthesized by the present invention is a new type of polymer material.

[0035] (2) The bio-based polyurethane synthesized in the present invention is a new type of polymer material. It not only retains the inherent biocompatibility and biodegradability of polyester, but can also be endowed with diversified functions through modification with multiple functional groups, such as achieving special properties such as water solubility, response to external stimuli (such as pH or temperature changes), and fluorescence; it can be applied to gene delivery, drug delivery, biological imaging agents and other fields.

[0036] (3) The synthesis method of the polymer is simple, the polydispersity is small, and it has good controllability.

[0037] (4) The glycine-based polyurethane prepared by the present invention can be depolymerized under certain conditions and is recyclable. The depolymerization conversion rate can reach 99% in a relatively short period of time, thus establishing a complete "monomer-polymer" recycling system and opening up an innovative direction for the development of a new generation of sustainable polymer materials with closed-loop recyclable properties. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] The present invention will be further described below in conjunction with the accompanying drawings and specific embodiments, and the above and / or other advantages of the present invention will become more apparent.

[0039] Figure 1 The monomer of Example 1 1 H NMR spectrum.

[0040] Figure 2The monomer of Example 1 13 C HMR diagram

[0041] Figure 3 The polymer of Example 4 1 H NMR spectrum.

[0042] Figure 4 The polymer of Example 4 13 C HMR diagram.

[0043] Figure 5 This is the matrix-assisted laser ionization desorption / ionization time-of-flight mass spectrum of the polymer in Example 4.

[0044] Figure 6 This is the GPC chart of the polymer in Example 4.

[0045] Figure 7 The polymer of Example 8 1 H NMR spectrum.

[0046] Figure 8 The polymer of Example 8 13 C HMR diagram.

[0047] Figure 9 The polymer of Example 10 1 H NMR spectrum.

[0048] Figure 10 The polymer of Example 10 13 C HMR diagram.

[0049] Figure 11 TGA-T of Examples 4, 8, and 10 d,5％ picture.

[0050] Figure 12 TGA-T of Examples 4, 8, and 10 d,max picture.

[0051] Figure 13 These are the DSC graphs of Examples 4, 8, and 10.

[0052] Figure 14 This is the DSC chart of Example 10. DETAILED DESCRIPTION

[0053] The present invention can be better understood according to the following examples. However, it is easy for those skilled in the art to understand that the contents described in the examples are only used to illustrate the present invention, and should not and will not limit the present invention described in detail in the claims.

[0054] The experimental methods described in the following examples are conventional methods unless otherwise specified; the reagents and materials are commercially available unless otherwise specified.

[0055] In the following examples, a 400 MHz Bruker nuclear magnetic resonance instrument was used to measure the products: the deuterated reagent used tetramethylsilane (TMS) as the internal standard, the H NMR test concentration was about 10 mg / mL, the C NMR test concentration was about 20 mg / mL, and the deuterated reagent was deuterated chloroform.

[0056] The molecular weight and molecular weight distribution of the glycine-based polyurethane described herein were determined using a Wyatt gel permeation chromatography (GPC) instrument. The polymer concentration in chromatographic-grade THF was approximately 4 mg / mL, using tetrahydrofuran (THF) as the mobile phase at a flow rate of 0.70 mL / min. Polystyrene (PS) was used as the standard sample. The molecular weight and molecular weight distribution of the polymer were determined using a relative method.

[0057] The topological structures of the polymers described herein were determined using a Microflex LRF mass spectrometer provided by Bruker Spectroscopy. The sample concentration was 10 mg / mL, using 2,5-dihydroxybenzoic acid (DHB) as the matrix at a concentration of 20 mg / mL in a solvent of 60% isopropanol and 40% chloroform. Sodium iodide was used as the cationic reagent at a concentration of 20 mg / mL in a methanol solvent. A mixture of sample / matrix / cationic reagent (1 / 10 / 1) was added dropwise to a test plate, dried, and then tested.

[0058] The thermal stability of the polymer in the present invention was tested using a TGA-550 instrument. 4-8 mg of the polymer product was kept at 100° C. for 10 minutes under a nitrogen atmosphere (gas flow rate of 50 ml / min), and then heated to 800° C. at a heating rate of 10° C. / min.

[0059] The glass transition temperature (T) of the polymer was measured by DSC-250. g ), melting temperature (T m ), crystallization temperature (T c The heating and cooling process of the polymer was carried out under a nitrogen atmosphere with a nitrogen flow rate of 50 ml / min. 4 to 8 mg of sample was weighed into a sample pan and heated from -60°C to 200°C at a rate of 10°C / min, maintained for 3 minutes, then cooled from 200°C to -60°C at a rate of 10°C / min, and finally heated back to 200°C.

[0060] Example 1:

[0061] At room temperature (25°C), glycine (7.507 g, 100 mmol, 1 equiv) and sodium hydroxide (3.997 g, 100 mol, 1 equiv) were added to a 50 mL pressure flask. A minimum amount of water was added and stirred until the glycine and sodium hydroxide dissolved. Once dissolved, propylene oxide (7 mL, 100 mmol, 1 equiv) was added dropwise to the pressure flask. The reaction was allowed to react at room temperature (25°C) for 24 h. After the reaction, 4 mol / L hydrochloric acid was added to adjust the pH to 5-6. After rotary evaporation to remove most of the water, the 50 mL reaction flask was evacuated using a Schlenk apparatus to yield a white solid. This solid was used directly in the next step without further purification.

[0062] The product from the previous step was added to 150 mL of dichloromethane (DCM) at 0°C and stirred to dissolve. 4-Dimethylaminopyridine (DMAP) (0.611 g, 25 mmol, 0.05 equiv) was then added, and di-tert-butyl dicarbonate (23 mL, 110 mmol, 1.1 equiv) was added dropwise using a syringe pump. After the addition was complete, the mixture was allowed to react at 0°C for 10 min and then at room temperature for 24 h. The DCM solvent was removed by rotary evaporation, and the intermediate product was diluted with a suitable amount of ethyl acetate (EA). The product was washed twice with distilled water and once with saturated brine. The organic phase was dried over anhydrous magnesium sulfate, filtered, and rotary evaporated to obtain a yellow liquid. The product was then purified by column chromatography (PE:EA = 40:1 to 8:1). After the majority of the solvent was removed by rotary evaporation, the remaining solvent was removed using a Schlenk apparatus to obtain a pale yellow liquid, the crude product. After column chromatography, petroleum ether (PE) was added to the monomer and heated. An appropriate amount of ethyl acetate (EA) was slowly added to completely dissolve the monomer. Insoluble impurities were filtered while hot, and the mixture was cooled to room temperature and transferred to a low-temperature refrigerator. White crystals eventually precipitated and the relatively pure monomer was obtained by rotary evaporation. Finally, a Schlenk apparatus was used to evacuate the 25 mL branched reaction flask and the vacuum distillation apparatus. The entire apparatus was then heated with a Bunsen burner to remove any residual moisture. After heating, argon was filled in for protection. This process was repeated three times and cooled to room temperature before use. The product after rotary evaporation was then subjected to vacuum distillation under the Schlenk apparatus to obtain pure, colorless, transparent liquid glycine-based azalide 1.

[0063] Example 2:

[0064] At room temperature (25°C), glycine (7.507 g, 100 mmol, 1 equiv) and sodium hydroxide (3.997 g, 100 mol, 1 equiv) were added to a 50 mL pressure bottle. A minimum amount of water was added and stirred until the glycine and sodium hydroxide dissolved. Once dissolved, 1,2-butylene oxide (8.8 mL, 100 mmol, 1 equiv) was added dropwise to the pressure bottle. The reaction was allowed to react at room temperature (25°C) for 24 h. After the reaction, 4 mol / L hydrochloric acid was added to adjust the pH to 5-6. After rotary evaporation to remove most of the water, the 50 mL reaction bottle was evacuated using a Schlenk apparatus to yield a white solid. This solid was used directly in the next step without further purification.

[0065] The product from the previous step was added to 150 mL of dichloromethane (DCM) at 0°C and stirred to dissolve. 4-Dimethylaminopyridine (DMAP) (0.611 g, 25 mmol, 0.05 equiv) was then added, and di-tert-butyl dicarbonate (23 mL, 110 mmol, 1.1 equiv) was added dropwise using a syringe pump. After the addition was complete, the mixture was allowed to react at 0°C for 10 min and then at room temperature for 24 h. The DCM solvent was removed by rotary evaporation, and the intermediate product was diluted with ethyl acetate (EA) and washed twice with distilled water and once with saturated brine. The organic phase was dried over anhydrous magnesium sulfate, filtered, and rotary evaporated to obtain a yellow liquid. Purification was then performed by column chromatography (PE:EA = 40:1 to 10:1). After the majority of the solvent was removed by rotary evaporation, the remaining solvent was removed using a Schlenk apparatus to obtain a pale yellow liquid, the crude product. After column chromatography, petroleum ether (PE) was added to the monomer and heated. An appropriate amount of ethyl acetate (EA) was slowly added to completely dissolve the monomer. Insoluble impurities were filtered while hot, and the mixture was cooled to room temperature and transferred to a low-temperature refrigerator. White crystals were eventually precipitated and then rotary distilled to obtain a relatively pure monomer. Finally, a Schlenk apparatus was used to evacuate the 25 mL branched reaction flask and the vacuum distillation apparatus. The entire apparatus was then baked with a Bunsen burner to remove any residual moisture. After baking, argon was filled in for protection. This process was repeated three times and cooled to room temperature before use. The product after rotary distillation was vacuum distilled under the Schlenk apparatus to obtain pure, colorless, transparent liquid glycine-based azalactone 2.

[0066] Example 3:

[0067] At room temperature (25°C), glycine (7.507 g, 100 mmol, 1 equiv) and sodium hydroxide (3.997 g, 100 mol, 1 equiv) were added to a 50 mL pressure bottle. A minimum amount of water was added and stirred until the glycine and sodium hydroxide dissolved. Once dissolved, 1,2-epoxyhexane (12 mL, 100 mmol, 1 equiv) was added dropwise to the pressure bottle. The reaction was allowed to react at room temperature (25°C) for 24 h. After the reaction, 4 mol / L hydrochloric acid was added to adjust the pH to 5-6. After rotary evaporation to remove most of the water, the 50 mL reaction bottle was evacuated using a Schlenk apparatus to yield a white solid. This solid was used directly in the next step without further purification.

[0068] The product from the previous step was added to 150 mL of dichloromethane (DCM) at 0°C and stirred to dissolve. 4-Dimethylaminopyridine (DMAP) (0.611 g, 25 mmol, 0.05 equiv) was then added, and di-tert-butyl dicarbonate (23 mL, 110 mmol, 1.1 equiv) was added dropwise using a syringe pump. After the addition was complete, the mixture was allowed to react at 0°C for 10 min and then at room temperature for 24 h. The DCM solvent was removed by rotary evaporation, and the intermediate product was diluted with ethyl acetate (EA) and washed twice with distilled water and once with saturated brine. The organic phase was dried over anhydrous magnesium sulfate, filtered, and rotary evaporated to obtain a yellow liquid. Purification was then performed by column chromatography (PE:EA = 40:1 to 10:1). After the majority of the solvent was removed by rotary evaporation, the remaining solvent was removed using a Schlenk apparatus to obtain a pale yellow liquid, the crude product. After column chromatography, petroleum ether (PE) was added to the monomer and heated. An appropriate amount of ethyl acetate (EA) was slowly added to completely dissolve the monomer. Insoluble impurities were filtered while hot, and the mixture was cooled to room temperature and transferred to a low-temperature refrigerator. White crystals eventually precipitated and the relatively pure monomer was obtained by rotary evaporation. Finally, a Schlenk apparatus was used to evacuate the 25 mL branched-end reaction flask and the vacuum distillation apparatus. The entire apparatus was then baked with a Bunsen burner to remove any residual moisture. After baking, argon was filled in for protection. This process was repeated three times and cooled to room temperature before use. The product after rotary evaporation was then vacuum distilled under the Schlenk apparatus to obtain pure, colorless, transparent liquid glycine-based azalactone 3.

[0069] Example 4:

[0070] Both ampoules were evacuated using a Schlenk apparatus and baked with a Bunsen burner to remove any residual moisture. After baking, the ampoules were filled with argon for protection. This process was repeated three times, cooled to room temperature, and transferred to a glove box. In the glove box, 1.2 mmol of glycine-based azalide 1 was weighed into ampoule 1 and dissolved in 350 μl of redistilled toluene. 0.012 mmol of TBD was weighed into ampoule 2, and 32 μl of toluene was added to dissolve the catalyst. 0.04 mmol of benzyl alcohol was then added and stirred at 0°C for 5 minutes. Finally, the dissolved monomer was added to the ampoule containing the catalyst and initiator to initiate polymerization.

[0071] After stirring at 0℃ for 20 minutes, 3-4 drops of the polymer solution were added to deuterated chloroform of benzoic acid to test the monomer conversion rate, and the rest were added to n-hexane dissolved with benzoic acid to quench and precipitate. After centrifugation at 10000r / min for 3 minutes, the supernatant was poured out, and a small amount of dichloromethane (DCM) was used to completely dissolve the polymer and added dropwise to n-hexane for precipitation. This was repeated three times, and the polymer product was placed in a drying dish and then vacuumed with a Schlenk device for 12 hours. The conversion rate was measured by the reaction solution. 1 The polymer structure and molecular weight were calculated by H NMR. 1 The polymer was characterized by H NMR and its dispersion was determined by GPC. The conversion rate was 74%, the polymer number-average molecular weight was 5110 g / mol, and the dispersion coefficient was 1.16. The glass transition temperature was 31°C, the initial decomposition temperature was 194°C, and the maximum decomposition temperature was 229°C.

[0072] Example 5:

[0073] Both ampoules were evacuated using a Schlenk apparatus and baked with a Bunsen burner to remove any residual moisture. After baking, the ampoules were filled with argon for protection. This process was repeated three times, cooled to room temperature, and transferred to a glove box. In the glove box, 15 mmol of glycine-based azalide 1 was weighed into ampoule 1 and dissolved in 3500 μl of redistilled toluene. 0.3 mmol of DBU and 0.3 mmol of (thio)urea (O-5) were weighed into ampoule 2, and 1280 μl of toluene was added to dissolve the catalyst. 0.005 mmol of phenylethanol was then added and stirred at 25°C for 5 minutes. Finally, the dissolved monomer was added to the ampoule containing the catalyst and initiator to initiate polymerization.

[0074] After stirring at 25°C for 40 minutes, 3 to 4 drops of the polymer solution were added to deuterated chloroform of benzoic acid to test the monomer conversion rate, and the remaining drops were added to n-hexane dissolved with benzoic acid to quench and precipitate. After centrifugation at 10,000 r / min for 3 minutes, the supernatant was poured out, and a small amount of dichloromethane (DCM) was used to completely dissolve the polymer and added dropwise to n-hexane for precipitation. This was repeated three times. The polymer product was placed in a drying dish and then vacuumed using a Schlenk apparatus for 12 hours. The conversion rate was calculated by 1H NMR of the reaction solution, the polymer structure and molecular weight were identified by 1H NMR, and the polymer dispersion was determined by GPC. The conversion rate was 60%, the polymer number average molecular weight was 3,875,600 g / mol, and the dispersion coefficient was 1.33.

[0075] Example 6:

[0076] Both ampoules were evacuated using a Schlenk apparatus and baked with a Bunsen burner to remove any residual moisture. After baking, the ampoules were filled with argon for protection. This process was repeated three times, cooled to room temperature, and transferred to a glove box. In the glove box, 1.2 mmol of glycine-based azalide 1 was weighed and placed in ampoule 1. 350 μl of redistilled tetrahydrofuran (THF) was added to dissolve it. 0.012 mmol of TBD was weighed and placed in ampoule 2. 32 μl of tetrahydrofuran (THF) was added to dissolve the catalyst. 0.012 mmol of phenylpropanol was then added and stirred at 25°C for 5 minutes. Finally, the dissolved monomer was added to the ampoule containing the catalyst and initiator to initiate polymerization.

[0077] After stirring at 25°C for 24 hours, 3 to 4 drops of the polymer solution were added to deuterated chloroform of benzoic acid to test the monomer conversion rate, and the rest were added to n-hexane dissolved with benzoic acid to quench and precipitate. After centrifugation at 10,000 r / min for 3 minutes, the supernatant was poured out, and a small amount of dichloromethane (DCM) was used to completely dissolve the polymer and added dropwise to n-hexane for precipitation. This was repeated three times, and the polymer product was placed in a drying dish and then vacuumed with a Schlenk device for 12 hours. The conversion rate was calculated by 1HNMR of the reaction solution, and the polymer structure and molecular weight were obtained by 1 The polymer was characterized by H NMR and its dispersion was determined by GPC. The conversion rate was 9%, the number average molecular weight of the polymer was 1200 g / mol, and the dispersion coefficient was 1.25.

[0078] Example 7:

[0079] Both ampoules were evacuated using a Schlenk apparatus and baked with a Bunsen burner to remove any residual moisture. After baking, the ampoules were filled with argon for protection. This process was repeated three times, cooled to room temperature, and transferred to a glove box. In the glove box, 5 mmol of glycine lactone monomer 1 was weighed and placed in ampoule 1. 1200 μl of redistilled toluene was added to dissolve it. 0.05 mmol of IMes was weighed and placed in ampoule 2. 392 μl of toluene was added to dissolve the catalyst. 0.01 mmol of 2,2-diphenylethanol was then added and stirred at 25°C for 5 minutes. Finally, the dissolved monomer was added to the ampoule containing the catalyst and initiator to initiate polymerization.

[0080] After stirring at 25°C for 24 hours, 3-4 drops of the polymer solution were added to deuterated chloroform of benzoic acid to test the monomer conversion rate, and the remaining drops were added to n-hexane dissolved with benzoic acid to quench and precipitate. After centrifugation at 10000r / min for 3 minutes, the supernatant was poured out, and a small amount of dichloromethane (DCM) was used to completely dissolve the polymer and added dropwise to n-hexane for precipitation. This was repeated three times, and the polymer product was placed in a drying dish and then vacuumed with a Schlenk device for 12 hours. The conversion rate was measured by the reaction solution. 1 The polymer structure and molecular weight were calculated by H NMR. 1 The polymer was characterized by H NMR and its dispersion was determined by GPC. The conversion rate was 48%, the polymer number average molecular weight was 10530 g / mol, and the dispersion coefficient was 1.36.

[0081] Example 8:

[0082] Both ampoules were evacuated using a Schlenk apparatus and baked with a Bunsen burner to remove any residual moisture. After baking, the ampoules were filled with argon for protection. This process was repeated three times, cooled to room temperature, and transferred to a glove box. In the glove box, 1.5 mmol of glycine-based azalide 2 was weighed and placed in ampoule 1. 400 μl of redistilled toluene was added to dissolve it. 0.009 mmol of TBD was weighed and placed in ampoule 2. 78 μl of toluene was added to dissolve the catalyst. 0.03 mmol of benzhydrol was then added and stirred at 0°C for 5 minutes. Finally, the dissolved monomer was added to the ampoule containing the catalyst and initiator to initiate polymerization.

[0083] After stirring at 0℃ for 1 hour, 3-4 drops of the polymer solution were added to deuterated chloroform of benzoic acid to test the monomer conversion rate, and the rest were added to n-hexane dissolved with benzoic acid to quench and precipitate. After centrifugation at 10000r / min for 3 minutes, the supernatant was poured out, and a small amount of dichloromethane (DCM) was used to completely dissolve the polymer and added dropwise to n-hexane for precipitation. This was repeated three times, and the polymer product was placed in a drying dish and then vacuumed with a Schlenk device for 12 hours. The conversion rate was measured by the reaction solution. 1The polymer structure and molecular weight were calculated by H NMR. 1 The polymer was characterized by H NMR and its dispersion was determined by GPC. The conversion rate was 60%, the polymer number-average molecular weight was 7060 g / mol, and the dispersion coefficient was 1.20. The glass transition temperature was 23°C, the initial decomposition temperature was 204°C, and the maximum decomposition temperature was 223°C.

[0084] Example 9:

[0085] Both ampoules were evacuated using a Schlenk apparatus and baked with a Bunsen burner to remove any residual moisture. After baking, the ampoules were filled with argon for protection. This process was repeated three times, cooled to room temperature, and transferred to a glove box. In the glove box, 5 mmol of glycine-based azalide 3 was weighed and placed in ampoule 1. 1200 μl of redistilled toluene was added to dissolve it. 0.1 mmol of TBD was weighed and placed in ampoule 2. 392 μl of toluene was added to dissolve the catalyst. 0.1 mmol of benzyl alcohol was then added and stirred at 0°C for 5 minutes. Finally, the dissolved monomer was added to the ampoule containing the catalyst and initiator to initiate polymerization.

[0086] After stirring at 0℃ for 1 hour, 3-4 drops of the polymer solution were added to deuterated chloroform of benzoic acid to test the monomer conversion rate, and the rest were added to n-hexane dissolved with benzoic acid to quench and precipitate. After centrifugation at 10000r / min for 3 minutes, the supernatant was poured out, and a small amount of dichloromethane (DCM) was used to completely dissolve the polymer and added dropwise to n-hexane for precipitation. This was repeated three times, and the polymer product was placed in a drying dish and then vacuumed with a Schlenk device for 12 hours. The conversion rate was measured by the reaction solution. 1 The polymer structure and molecular weight were calculated by H NMR. 1 The polymer was characterized by H NMR and its dispersion was determined by GPC. The conversion rate was 67%, the polymer number-average molecular weight was 8730 g / mol, and the dispersion coefficient was 1.22. The glass transition temperature was 10°C, the initial decomposition temperature was 201°C, the maximum decomposition temperature was 210°C, the cold crystallization temperature was 63°C, and the melting temperature was 144°C.

[0087] Example 10:

[0088] Both ampoules were evacuated using a Schlenk apparatus and baked with a Bunsen burner to remove any residual moisture. After baking, the ampoules were filled with argon for protection. This process was repeated three times, cooled to room temperature, and transferred to a glove box. In the glove box, 10 mmol of glycine-based azalide 3 was weighed into ampoule 1 and dissolved in 2000 μl of ultra-dry N,N-dimethylformamide (DMF). 0.05 mmol of TBD was weighed into ampoule 2, and 500 μl of ultra-dry N,N-dimethylformamide (DMF) was added to dissolve the catalyst. 0.05 mmol of benzyl alcohol was then added and stirred at 0°C for 5 minutes. Finally, the dissolved monomer was added to the ampoule containing the catalyst and initiator to initiate polymerization.

[0089] After stirring at 0℃ for 4 hours, 3-4 drops of the polymer solution were added to deuterated chloroform of benzoic acid to test the monomer conversion rate, and the rest were added to n-hexane dissolved with benzoic acid to quench and precipitate. After centrifugation at 10000r / min for 3 minutes, the supernatant was poured out, and a small amount of dichloromethane (DCM) was used to completely dissolve the polymer and added dropwise to n-hexane for precipitation. This was repeated three times, and the polymer product was placed in a drying dish and then vacuumed with a Schlenk device for 12 hours. The conversion rate was measured by the reaction solution. 1 The polymer structure and molecular weight were calculated by H NMR. 1 The polymer was characterized by H NMR and its dispersion was determined by GPC. The conversion rate was 14%, the polymer number average molecular weight was 7260 g / mol, and the dispersion coefficient was 1.33.

[0090] Example 11:

[0091] Both ampoules were evacuated using a Schlenk apparatus and baked with a Bunsen burner to remove any residual moisture. After baking, the ampoules were filled with argon for protection. This process was repeated three times, cooled to room temperature, and transferred to a glove box. In the glove box, 5 mmol of glycine-based azalide 3 was weighed into ampoule 1 and dissolved in 800 μl of ultra-dry dichloromethane (DCM). 0.01 mmol of Brønsted base (TBD) was weighed into ampoule 2, and 200 μl of ultra-dry dichloromethane (DCM) was added to dissolve the catalyst. 0.01 mmol of benzyl alcohol was then added and stirred at 25°C for 5 minutes. Finally, the dissolved monomer was added to the ampoule containing the catalyst and initiator to initiate polymerization.

[0092] After stirring at 25°C for 6 hours, 3-4 drops of the polymer solution were added to deuterated chloroform of benzoic acid to test the monomer conversion rate, and the remaining drops were added to n-hexane dissolved with benzoic acid to quench and precipitate. After centrifugation at 10000r / min for 3 minutes, the supernatant was poured out, and a small amount of dichloromethane (DCM) was used to completely dissolve the polymer and then added dropwise to n-hexane for precipitation. This was repeated three times, and the polymer product was placed in a drying dish and then vacuumed with a Schlenk device for 12 hours. The conversion rate was measured by the reaction solution. 1 The polymer structure and molecular weight were calculated by H NMR. 1 The polymer was characterized by H NMR and its dispersion was determined by GPC. The conversion rate was 17%, the polymer number average molecular weight was 21810 g / mol, and the dispersion coefficient was 1.39.

[0093] Disaggregation experiments:

[0094] The polymer prepared in Example 4 (0.1000 g), 1,5,7-triazabicyclo[4.4.0]dec-5-ene (TBD) (1 mol%), and toluene (5 mL) were transferred to a pressure bottle and heated at 100° C. for 10 minutes. The yield was calculated by the reaction mixture. 1 The structure was obtained by H NMR calculation. 1 H NMR identification showed that the product was glycine lactone monomer with a purity >99% and a recovery rate of 99%.

[0095] The above-described embodiments merely illustrate several implementations of the present invention, and while their descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the present invention. It should be noted that a person skilled in the art would be able to make numerous variations and improvements without departing from the spirit of the present invention, all of which fall within the scope of protection of the present invention. Therefore, the scope of protection of the present invention shall be determined by the appended claims.

Claims

1. A glycine-based azalide, characterized in that The glycine-based aza lactone is shown in formula II 2. A method for preparing the glycine-based azalide according to claim 1, wherein the specific process steps and conditions of the preparation method are as follows: At room temperature (25°C), glycine (7.507 g, 100 mmol, 1 equiv) and sodium hydroxide (3.997 g, 100 mol, 1 equiv) were added to a 50 mL pressure bottle. Water was added and stirred until the glycine and sodium hydroxide dissolved. Epoxide (100 mmol, 1 equiv) was then added dropwise to the pressure bottle. The reaction was allowed to react at room temperature (25°C) for 24 h. After the reaction, hydrochloric acid was added to adjust the pH to 5-6. The solution was then rotary evaporated, concentrated, and vacuum-evacuated to yield a white solid. This solid was used directly in the next step without further purification. The product from the previous step, 4-dimethylaminopyridine (DMAP) (0.611 g, 25 mmol, 0.05 equiv), was added to 150 mL of dichloromethane (DCM) at 0°C and stirred to dissolve. Di-tert-butyl dicarbonate (23 mL, 110 mmol, 1.1 equiv) was then added dropwise. The mixture was allowed to react at 0°C for 10 min and then at room temperature for 24 h. After completion of the reaction, the mixture was concentrated by rotary evaporation. The intermediate product was diluted with a suitable amount of ethyl acetate (EA) and washed twice with distilled water and once with saturated brine. The organic phase was dried over anhydrous magnesium sulfate, filtered, and rotary evaporated to yield a yellow liquid. Purification by column chromatography (PE:EA = 40:1 to 8:1) afforded the colorless, transparent glycine-based azalide (yield 20-50%). The general structural formula of epoxide is shown in Formula III:

3. A bio-based polyurethane using the glycine-based azalactone according to claim 1, wherein the bio-based polyurethane has a general structural formula as shown in Formula I: in, The general structure of Y is shown in Formula IV: The number average molecular weight of the glycine polyurethane is 2000 to 400000 g mol -1 .

4. The method for preparing the glycine polyamino ester according to claim 1 or 2, characterized in that: The following steps are involved: reacting a catalyst represented by formula V, a solvent, an initiator, and a glycine-based azalactone represented by formula II; 5. The preparation method according to claim 2, characterized in that The catalyst is any one of 1,5,7-triazabicyclo[4.4.0]dec-5-ene, 1,8-diazabicyclo[5.4.0]undec-7-ene, and 1,3-dimesityl imidazole-2-ylidene; the solvent is any one of toluene, tetrahydrofuran, dichloromethane, and N,N-dimethylformamide; and the initiator is any one of methanol, ethanol, isopropanol, tert-butanol, benzyl alcohol, phenylethyl alcohol, phenylpropyl alcohol, diphenylmethanol, and 2,2-diphenylethanol.

6. The preparation method according to claim 2, characterized in that The molar ratio of the glycine-based azalactone, the initiator and the catalyst is (10-3000):1:(0.1-5); the reaction temperature is -20-100° C.; and the reaction time is 5-1440 minutes.

7. Use of the glycine-based polyamino ester according to claim 1 or 2 or the glycine-based polyamino ester prepared by the method according to any one of claims 3 to 6 in the preparation of chemically recyclable materials.

Images