A bromine-functionalized polyester and a method for preparing the same

Abstract

The application discloses a kind of bromine functionalized polyester and its preparation method, the structural formula of the bromine functionalized polyester is as shown in formula I, the preparation method of the bromine functionalized polyester, including urea or thiourea, brønsted base, solvent, initiator and bromine substitution bridged lactone monomer reaction.Compared with existing aliphatic polyester polymer material, the multifunctionality of the bromine functionalized polyester provided in the application is enriched, the application value is improved, and the application field is expanded.Meanwhile, the prepared bromine functionalized polyester has recyclability.Secondly, the preparation method of the bromine functionalized polyester of the application is simple to operate, controllable, the product yield is high, and subsequent conversion can occur.

Description

Technical Field

[0001] This invention relates to the field of polymer synthetic chemistry, specifically to a brominated functionalized polyester and its preparation method. Background Technology

[0002] This section provides only background information relevant to this disclosure and is not necessarily prior art.

[0003] The widespread use of plastics results in millions of units of plastic waste generated annually, most of which end up incinerated, landfilled, or dumped into the ocean. This leads to enormous energy losses and severe environmental pollution. Plastic pollution and energy waste have drawn the attention of governments worldwide, and addressing the plastic crisis has become a global concern. In this context, plastic recycling is an effective method for solving the plastic problem. Chemical recycling offers a solution, where recycled plastics are depolymerized under mild conditions into their original monomers. These monomers are then repolymerized to create plastics with superior properties, establishing a closed-loop lifecycle of "monomer-polymer-monomer." Currently, significant progress has been made in the chemical recycling of monomers from polyesters, polysulfides, polycarbonates, and polyamides. Among these recyclable polymers, aliphatic polyesters, due to their excellent properties, hold promise as a substitute for petroleum-based plastics.

[0004] However, the current functionalization of polyesters is limited and cannot meet the diverse practical application needs. Brominated functionalized polyester materials, as an important class of polymer materials, can undergo various transformations, such as copolymerization, crosslinking, and grafting, to prepare materials with special properties. Summary of the Invention

[0005] Purpose of the invention: The technical problem to be solved by the present invention is to provide a brominated functionalized polyester and its preparation method, which addresses the shortcomings of the prior art.

[0006] To solve the above-mentioned technical problems, the present invention discloses the following technical solution:

[0007] In a first aspect, the present invention discloses a brominated functionalized polyester, which is shown in general formula I:

[0008]

[0009] in,

[0010] Y is selected from methoxy, ethoxy, isopropoxy, tert-butoxy, benzyloxy, phenylethoxy, phenylpropoxy, diphenylmethoxy, and 2,2-diphenylethoxy.

[0011] n is any integer selected from 10 to 2000;

[0012] The number-average molecular weight of the brominated functionalized polyester is 2000–400000 g / mol. -1 For example, 4000, 5000, 6000, 7000, 15000, 16000, 56000, 80000, 90000, 190000, 370000, 380000 g mol -1 In some embodiments, n is selected from any integer from 10 to 2000 such that the number-average molecular weight of the brominated functionalized polyester is 2000 to 400000 g mol. -1 ;

[0013] The dispersion coefficient of the brominated functionalized polyester is 1.00-1.50, such as 1.20, 1.30, or 1.40.

[0014] In some embodiments, the brominated functionalized polyester is any one of those shown in Formula II;

[0015]

[0016] Secondly, the present invention discloses a method for preparing the above-mentioned polymer.

[0017] The method includes the following steps: reacting urea or thiourea of ​​Formula III, Brønsted base, solvent, initiator, and bromo-substituted bridged-ring lactone monomer of Formula IV; further, the method includes the following steps: stirring urea or thiourea of ​​Formula III, Brønsted base, solvent, and initiator for 1-8 min, and then adding bromo-substituted bridged-ring lactone monomer of Formula IV for reaction; even further, the method includes the following steps: stirring urea or thiourea of ​​Formula III, Brønsted base, solvent, and initiator for 3-6 min, and then adding bromo-substituted bridged-ring lactone monomer of Formula IV for reaction.

[0018] In some embodiments, the method includes the following steps: stirring urea or thiourea of ​​Formula III, Brønsted base, a first solvent and an initiator at 25-100°C for 3-6 min, then adding a solution of a bromo-substituted bridged ring lactone monomer of Formula IV and a second solvent, and continuing to stir the reaction at 25-100°C for 5 min-24 h; the first solvent and the second solvent are the same solvent; in some embodiments, the molar volume ratio of the bromo-substituted bridged ring lactone monomer of Formula IV to the first solvent and the second solvent is 1.5-2.5 mol / L, preferably 2 mol / L.

[0019] The structure of urea or thiourea represented by Formula III is as follows:

[0020]

[0021] in,

[0022] X is selected from O or S;

[0023] R 1 -R 4 They were independently selected from H, OMe, Cl, and CF3, respectively.

[0024] Furthermore,

[0025] When X is selected from O, R 1 -R 4 The functional groups are:

[0026] R 1 =OMe,R 2 -R 4 =H;

[0027] or R 1 -R 4 =H;

[0028] or R 1 =Cl, R 2 -R 4 =H;

[0029] or R 1 =CF3,R 2 -R 4 =H;

[0030] or R 1 -R 2 =CF3,R 3 -R 4 =H;

[0031] or R 1 -R 3 =CF3,R 4 =H;

[0032] or R 1 -R 4 =CF3;

[0033] When X is selected from S, R 1 -R 4 =CF3.

[0034] Furthermore, the structure of the urea or thiourea shown in Formula III is any one of U1 to U9 or TU1;

[0035]

[0036]

[0037] The Brønsted base includes 1,5,7-triazabicyclo[4.4.0]dec-5-ene (TBD), diphenyl phosphate (DPP), 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU), 1,3-dimethyltrimethylimidazolium-2-ene (IMes), and 7-methyl-1,5,7-triazabicyclo[4.4.0]dec-5-ene (MTBD).

[0038] The reaction solvent is one of toluene, tetrahydrofuran, dichloromethane, and N,N-dimethylformamide.

[0039] The initiator is an alcohol; preferably, the initiator is methanol, ethanol, isopropanol, tert-butanol, benzyl alcohol, phenylethanol, phenylpropanol, diphenylmethanol, or 2,2-diphenylethanol.

[0040] The structural formula of the bromine-substituted bridged ring lactone monomer represented by formula IV is as follows:

[0041]

[0042] Wherein, the molar ratio of the bromine-substituted bridged ring lactone monomer represented by Formula IV, the urea or thiourea represented by Formula III, the Brønsted base, and the initiator is 10-2000:1-20:1-20:1, 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.

[0043] The reaction temperature is 25–100°C; the reaction time is 5–1440 min.

[0044] Thirdly, the present invention discloses the application of the brominated functionalized polyester described in the first aspect or the brominated functionalized polyester prepared by the method described in the second aspect in the preparation of chemically recyclable materials.

[0045] The brominated functionalized polyester prepared by this invention can rapidly depolymerize to monomers under certain conditions, with a purity of 99% and good recyclability. The degradation conditions are as follows: p-toluenesulfonic acid as catalyst (2-10 mol% of polymer), reaction temperature of 60-120℃, toluene as solvent (polymer concentration of 0.3-0.7 g / mL), reaction time of 2-12 h, and a recovery rate of 60-80%.

[0046] Beneficial effects:

[0047] (1) The bromine-functionalized polyester synthesized in this invention is a new type of polymer material. Its bromine functional groups have a wide range of physical and chemical properties, including excellent flame retardancy and the ability to initiate free radical reactions (crosslinking or graft polymerization), which can endow the material with diverse functionalizations and properties and expand its application fields.

[0048] (2) The brominated functionalized polyester prepared by the present invention can be depolymerized under certain conditions and is recyclable.

[0049] (3) The synthesis method provided by the present invention is simple, highly controllable, and has a high product yield. Attached Figure Description

[0050] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments, and the advantages of the present invention in the above and / or other aspects will become clearer.

[0051] Figure 1 Polymer of Example 1 1 H NMR spectrum.

[0052] Figure 2 Polymer of Example 1 13 C HMR plot.

[0053] Figure 3 The image shows the matrix-assisted laser ionization desorption time-of-flight mass spectrum of the polymer in Example 1.

[0054] Figure 4 The image shows the polymer GPC diagram for Example 1. Detailed Implementation

[0055] The present invention can be better understood from the following embodiments. However, those skilled in the art will readily understand that the descriptions in the embodiments are for illustrative purposes only and should not, and will not, limit the invention as detailed in the claims.

[0056] Unless otherwise specified, the experimental methods described in the following examples are conventional methods; unless otherwise specified, the reagents and materials are commercially available.

[0057] In the following examples, the products were measured using a 400MHz Bruker nuclear magnetic resonance instrument: the deuteration reagent was tetramethylsilane (TMS) as an internal standard, the concentration for 1H NMR was approximately 10 mg / mL, the concentration for 1C NMR was approximately 20 mg / mL, and the deuteration reagent was deuterated chloroform.

[0058] The molecular weight and molecular weight distribution of the brominated functionalized polyester described in this invention were obtained by Wyatt gel permeation chromatography. Tetrahydrofuran (THF) was used as the mobile phase at a flow rate of 0.70 mL / min. The concentration of the polymer in chromatographic grade THF was approximately 4 mg / mL. Polystyrene (PS) was used as a standard, and the molecular weight and molecular weight distribution of the polymer were determined using a relative method.

[0059] The topological structure of the polymer in this invention was determined using a Microflex LRF mass spectrometer provided by Bruker Spectroscopy Instruments. The sample concentration was 10 mg / mL, with 2,5-dihydroxybenzoic acid (DHB) as the matrix at a concentration of 20 mg / mL. The solvents were 60% isopropanol and 40% chloroform. Sodium iodide was used as the cation exchange reagent at a concentration of 20 mg / mL in methanol. The final mixture of sample / matrix / cation exchange reagent was prepared in a 1:10:1 ratio, added dropwise to the test plate, dried, and then analyzed.

[0060] The catalysts described in the following examples are Brønsted base and (thio)urea. The (thio)urea described in this invention is thiourea or urea, specifically having any one of U1 to U9 or as shown in TU1.

[0061] Example 1:

[0062] Two ampoules were evacuated using a Schlenk apparatus and simultaneously baked with a Bunsen burner to remove residual moisture. After baking, they were purged with argon for protection, and this process was repeated three times. The ampoules were then cooled to room temperature and transferred to a glove box. In the glove box, 1.5 mmol of a brominated bridged-ring lactone monomer was weighed into ampoule #1, and 400 μl of redistilled toluene was added to dissolve it. 0.05 mmol of Brønsted base (DBU) and 0.05 mmol of thiourea (U9) were weighed into ampoule #2, and 300 μl of toluene was added to dissolve the catalyst. Then, 0.05 mmol of benzyl alcohol was added, and the mixture was stirred at 25°C for 5 minutes. Finally, the dissolved monomer was added to the ampoule containing the catalyst and initiator to begin polymerization.

[0063] After stirring at 25°C for 10 minutes, 3-4 drops of the polymer solution were added dropwise to deuterated chloroform containing benzoic acid to test the monomer conversion. The remainder was added dropwise to ice-cold methanol containing dissolved benzoic acid to quench the precipitate. After centrifugation at 10000 rpm for 3 minutes, the supernatant was discarded. A small amount of dichloromethane (DCM) was then used to completely dissolve the polymer, which was then added dropwise to ice-cold methanol to precipitate. This process was repeated three times. The polymer product was placed in a desiccator and then vacuum-sealed for 12 hours using a Schlenk apparatus. The conversion rate was measured by analyzing the reaction mixture. 1 The polymer structure and molecular weight were obtained through H NMR calculations. 1The polymer was identified by ¹H NMR and its dispersibility was determined by GPC. The conversion rate was 98%, the number-average molecular weight was 5070 g / mol, and the dispersibility index was 1.20.

[0064] Example 2:

[0065] Two ampoules were evacuated using a Schlenk apparatus and simultaneously baked with a Bunsen burner to remove residual moisture. After baking, they were purged with argon gas for protection. This process was repeated three times, followed by cooling to room temperature and transferring to a glove box. In the glove box, 1.5 mmol of the brominated bridged-ring lactone monomer was weighed into ampoule #1, and 400 μl of redistilled toluene was added to dissolve it. 0.03 mmol of Brønsted base (MTBD) and 0.03 mmol of (thio)urea (U 8) were weighed into ampoule #2, and 320 μl of toluene was added to dissolve the catalyst. Then, 0.03 mmol of phenylethanol was added, and the mixture was stirred at 100 °C for 5 minutes. Finally, the dissolved monomer was added to the ampoule containing the catalyst and initiator to begin polymerization.

[0066] After stirring at 100℃ for 20 minutes, 3-4 drops of the polymer solution were added dropwise to deuterated chloroform of benzoic acid to test the monomer conversion. The remainder was added dropwise to ice-cold methanol containing dissolved benzoic acid to quench the precipitate. After centrifugation at 10000 r / min for 3 minutes, the supernatant was discarded. A small amount of dichloromethane (DCM) was then used to completely dissolve the polymer, which was then added dropwise to ice-cold methanol to precipitate. This process was repeated three times. The polymer product was placed in a desiccator and then evacuated under vacuum for 12 hours using a Schlenk apparatus. The conversion rate was calculated using 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 75%, the number-average molecular weight was 7290 g / mol, and the dispersion index was 1.26.

[0067] Example 3:

[0068] Two ampoules were evacuated using a Schlenk apparatus and simultaneously baked with a Bunsen burner to remove residual moisture. After baking, they were purged with argon for protection. This process was repeated three times, followed by cooling to room temperature and transferring to a glove box. In the glove box, 5 mmol of the brominated bridged-ring lactone monomer was weighed into ampoule #1, and 2000 μl of redistilled tetrahydrofuran (THF) was added to dissolve it. 0.05 mmol of Brønsted base (TBD) and 0.05 mmol of (thio)urea (U 7) were weighed into ampoule #2, and 450 μl of tetrahydrofuran (THF) was added to dissolve the catalyst. Then, 0.05 mmol of phenylpropanol was added, and the mixture was stirred at 25°C for 5 minutes. Finally, the dissolved monomer was added to the ampoule containing the catalyst and initiator to begin polymerization.

[0069] After stirring at 25°C for 1 hour, 3-4 drops of the polymer solution were added dropwise to deuterated chloroform containing benzoic acid to test the monomer conversion. The remainder was added dropwise to ice-cold methanol containing dissolved benzoic acid to quench the precipitate. After centrifugation at 10000 rpm for 3 minutes, the supernatant was discarded. The polymer was then completely dissolved with a small amount of dichloromethane (DCM) and added dropwise to ice-cold methanol to precipitate. This process was repeated three times. The polymer product was placed in a desiccator and then vacuum-sealed for 12 hours using a Schlenk apparatus. The conversion rate was measured by analyzing the reaction mixture. 1 The polymer structure and molecular weight were obtained through H NMR calculations. 1 The polymer was identified by ¹H NMR and its dispersibility was determined by GPC. The conversion rate was 82%, the number-average molecular weight was 15720 g / mol, and the dispersibility index was 1.32.

[0070] Example 4:

[0071] Two ampoules were evacuated using a Schlenk apparatus and simultaneously baked with a Bunsen burner to remove residual moisture. After baking, they were purged with argon gas for protection. This process was repeated three times, followed by cooling to room temperature and transferring to a glove box. In the glove box, 3 mmol of the brominated bridged-ring lactone monomer was weighed into ampoule #1, and 1000 μl of redistilled toluene was added to dissolve it. 0.01 mmol of Brønsted base (TBD) and 0.01 mmol of (thio)urea (U 7) were weighed into ampoule #2, and 490 μl of toluene was added to dissolve the catalyst. Then, 0.01 mmol of diphenylmethanol was added, and the mixture was stirred at 25 °C for 5 minutes. Finally, the dissolved monomer was added to the ampoule containing the catalyst and initiator to begin polymerization.

[0072] After stirring at 25°C for 2 hours, 3-4 drops of the polymer solution were added dropwise to deuterated chloroform containing benzoic acid to test the monomer conversion. The remainder was added dropwise to ice-cold methanol containing dissolved benzoic acid to quench the precipitate. After centrifugation at 10000 rpm for 3 minutes, the supernatant was discarded. The polymer was then completely dissolved with a small amount of dichloromethane (DCM) and added dropwise to ice-cold methanol to precipitate. This process was repeated three times. The polymer product was placed in a desiccator and then vacuum-sealed for 12 hours using a Schlenk apparatus. The conversion rate was measured by analyzing the reaction mixture. 1 The polymer structure and molecular weight were obtained through H NMR calculations. 1 The polymer was identified by 1H NMR and its dispersibility was determined by GPC. The conversion rate was 97%, the number-average molecular weight was 55,700 g / mol, and the dispersibility index was 1.35.

[0073] Example 5:

[0074] Two ampoules were evacuated using a Schlenk apparatus and simultaneously baked with a Bunsen burner to remove residual moisture. After baking, they were purged with argon gas for protection. This process was repeated three times, followed by cooling to room temperature and transferring to a glove box. In the glove box, 5 mmol of the brominated bridged-ring lactone monomer was weighed into ampoule #1, and 2000 μl of redistilled toluene was added to dissolve it. 0.02 mmol of Brønsted base (IMes) and 0.02 mmol of (thio)urea (U 1) were weighed into ampoule #2, and 490 μl of toluene was added to dissolve the catalyst. Then, 0.01 mmol of 2,2-diphenylethanol was added, and the mixture was stirred at 25 °C for 5 minutes. Finally, the dissolved monomer was added to the ampoule containing the catalyst and initiator to begin polymerization.

[0075] After stirring at 25°C for 18 hours, 3-4 drops of the polymer solution were added dropwise to deuterated chloroform containing benzoic acid to test the monomer conversion. The remainder was added dropwise to ice-cold methanol containing dissolved benzoic acid to quench the precipitate. The mixture was centrifuged at 10000 rpm for 3 minutes, the supernatant was discarded, and a small amount of dichloromethane (DCM) was used to completely dissolve the polymer, which was then added dropwise to ice-cold methanol to precipitate. This process was repeated three times. The polymer product was placed in a desiccator and then vacuum-sealed for 12 hours using a Schlenk apparatus. The conversion rate was measured by analyzing the reaction mixture. 1 The polymer structure and molecular weight were obtained through H NMR calculations. 1 The polymer was identified by ¹H NMR and its dispersibility was determined by GPC. The conversion rate was 83%, the number-average molecular weight was 79460 g / mol, and the dispersibility index was 1.28.

[0076] Example 6:

[0077] Two ampoules were evacuated using a Schlenk apparatus and simultaneously baked with a Bunsen burner to remove residual moisture. After baking, they were purged with argon gas for protection. This process was repeated three times, followed by cooling to room temperature and transferring to a glove box. In the glove box, 5 mmol of the brominated bridged-ring lactone monomer was weighed into ampoule #1, and 1000 μl of redistilled toluene was added to dissolve it. 0.09 mmol of Brønsted base (DBU) and 0.09 mmol of thiourea (U9) were weighed into ampoule #2, and 1490 μl of toluene was added to dissolve the catalyst. Then, 0.01 mmol of benzyl alcohol was added, and the mixture was stirred at 25 °C for 5 minutes. Finally, the dissolved monomer was added to the ampoule containing the catalyst and initiator to begin polymerization.

[0078] After stirring at 25°C for 18 hours, 3-4 drops of the polymer solution were added dropwise to deuterated chloroform containing benzoic acid to test the monomer conversion. The remainder was added dropwise to ice-cold methanol containing dissolved benzoic acid to quench the precipitate. The mixture was centrifuged at 10000 rpm for 3 minutes, the supernatant was discarded, and a small amount of dichloromethane (DCM) was used to completely dissolve the polymer, which was then added dropwise to ice-cold methanol to precipitate. This process was repeated three times. The polymer product was placed in a desiccator and then vacuum-sealed for 12 hours using a Schlenk apparatus. The conversion rate was measured by analyzing the reaction mixture. 1 The polymer structure and molecular weight were obtained through H NMR calculations. 1 The polymer was identified by ¹H NMR and its dispersity was determined by GPC. The conversion rate was 99%, the number-average molecular weight was 91,800 g / mol, and the dispersity index was 1.22.

[0079] Example 7:

[0080] Two ampoules were evacuated using a Schlenk apparatus and simultaneously baked with a Bunsen burner to remove residual moisture. After baking, they were purged with argon gas for protection. This process was repeated three times, followed by cooling to room temperature and transferring to a glove box. In the glove box, 10 mmol of the brominated bridged-ring lactone monomer was weighed into ampoule #1, and 2500 μl of redistilled toluene was added to dissolve it. 0.1 mmol of Brønsted base (DBU) and 0.1 mmol of thiourea (U9) were weighed into ampoule #2, and 2490 μl of toluene was added to dissolve the catalyst. Then, 0.01 mmol of benzyl alcohol was added, and the mixture was stirred at 25 °C for 5 minutes. Finally, the dissolved monomer was added to the ampoule containing the catalyst and initiator to begin polymerization.

[0081] After stirring at 25°C for 24 hours, 3-4 drops of the polymer solution were added dropwise to deuterated chloroform containing benzoic acid to test the monomer conversion. The remainder was added dropwise to ice-cold methanol containing dissolved benzoic acid to quench the precipitate. The mixture was centrifuged at 10000 rpm for 3 minutes, the supernatant was discarded, and a small amount of dichloromethane (DCM) was used to completely dissolve the polymer, which was then added dropwise to ice-cold methanol to precipitate. This process was repeated three times. The polymer product was placed in a desiccator and then vacuum-sealed using a Schlenk apparatus for 12 hours. The conversion rate was measured by analyzing the reaction mixture. 1 The polymer structure and molecular weight were obtained through H NMR calculations. 1 The polymer was identified by ¹H NMR and its dispersity was determined by GPC. The conversion rate was 99%, the number-average molecular weight was 189,220 g / mol, and the dispersity index was 1.22.

[0082] Example 8:

[0083] Two ampoules were evacuated using a Schlenk apparatus and simultaneously baked with a Bunsen burner to remove residual moisture. After baking, they were purged with argon gas for protection. This process was repeated three times, followed by cooling to room temperature and transferring to a glove box. In the glove box, 20 mmol of the brominated bridged-ring lactone monomer was weighed into ampoule #1, and 5000 μl of redistilled toluene was added to dissolve it. 0.2 mmol of Brønsted base (DBU) and 0.2 mmol of (thio)urea (U 9) were weighed into ampoule #2, and 4990 μl of toluene was added to dissolve the catalyst. Then, 0.01 mmol of benzyl alcohol was added, and the mixture was stirred at 25 °C for 5 minutes. Finally, the dissolved monomer was added to the ampoule containing the catalyst and initiator to begin polymerization.

[0084] After stirring at 25°C for 24 hours, 3-4 drops of the polymer solution were added dropwise to deuterated chloroform containing benzoic acid to test the monomer conversion. The remainder was added dropwise to ice-cold methanol containing dissolved benzoic acid to quench the precipitate. The mixture was centrifuged at 10000 rpm for 3 minutes, the supernatant was discarded, and a small amount of dichloromethane (DCM) was used to completely dissolve the polymer, which was then added dropwise to ice-cold methanol to precipitate. This process was repeated three times. The polymer product was placed in a desiccator and then vacuum-sealed using a Schlenk apparatus for 12 hours. The conversion rate was measured by analyzing the reaction mixture. 1 The polymer structure and molecular weight were obtained through H NMR calculations. 1 The polymer was identified by ¹H NMR and its dispersity was determined by GPC. The conversion rate was 98%, the number-average molecular weight was 374,510 g / mol, and the dispersity index was 1.24.

[0085] Example 9:

[0086] The polymer (0.5000 g) prepared in Example 1, p-toluenesulfonic acid (2 mol%), and toluene (1 mL) were transferred to a pressure-resistant bottle and heated at 120 °C for 12 hours. The yield was obtained by measuring the reaction mixture. 1 The structure was obtained through H NMR calculations. 1 H NMR analysis revealed that the product was a bromine-substituted bridged ring lactone monomer with a recovery rate of 70%.

[0087] The embodiments described above are merely illustrative of several implementations of the present invention, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of the present invention. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these modifications and improvements all fall within the scope of protection of the present invention. Therefore, the scope of protection of this patent should be determined by the appended claims.

Claims

1. A brominated functionalized polyester as shown in Formula I; Ⅰ； in, Y is selected from methoxy, ethoxy, isopropoxy, tert-butoxy, benzyloxy, phenylethoxy, phenylpropoxy, diphenylmethoxy, and 2,2-diphenylethoxy. The number-average molecular weight of the brominated functionalized polyester is 2000~400000 g mol. -1 .

2. The brominated functionalized polyester according to claim 1, characterized in that, The brominated functionalized polyester is any one of those shown in Formula II; II.

3. The method for preparing the brominated functionalized polyester according to claim 1 or 2, characterized in that, Includes the following steps: The reaction involves reacting the urea or thiourea of ​​Formula III, a Brønsted base, a solvent, an initiator, and the brominated bridged-ring lactone monomer of Formula IV; the reaction temperature is 25–100 °C; the molar ratio of the brominated bridged-ring lactone monomer of Formula IV, the urea or thiourea of ​​Formula III, the Brønsted base, and the initiator is 10–2000:1–20:1–20:

1. Ⅲ； in, X is selected from O or S; R 1 -R 4 They were independently selected from H, OMe, Cl, and CF3, respectively; Ⅳ。 4. The preparation method according to claim 3, characterized in that, In the urea or thiourea shown in Formula III; When X is selected from O, R 1 -R 4 The functional groups are: R 1 =OMe,R 2 -R 4 =H; or R 1 -R 4 =H; or R 1 = Cl, R 2 -R 4 = H; or R 1 =CF3, R 2 -R 4 =H; or R 1 -R 2 =CF3, R 3 -R 4 =H; or R 1 -R 3 =CF3, R 4 =H; or R 1 -R 4 =CF3; When X is selected from S, R 1 -R 4 =CF3.

5. The preparation method according to claim 3, characterized in that, The Brønsted base includes 1,5,7-triazabicyclo[4.4.0]dec-5-ene, diphenyl phosphate, 1,8-diazabicyclo[5.4.0]undec-7-ene, 1,3-dimethoxyimidazol-2-ylene, and 7-methyl-1,5,7-triazabicyclo[4.4.0]dec-5-ene.

6. The preparation method according to claim 3, characterized in that, The solvent is any one of toluene, tetrahydrofuran, dichloromethane, and N,N-dimethylformamide.

7. The preparation method according to claim 3, characterized in that, The initiator is an alcohol.

8. The preparation method according to claim 7, characterized in that, The initiator is any one of methanol, ethanol, isopropanol, tert-butanol, benzyl alcohol, phenylethanol, phenylpropanol, diphenylmethanol, and 2,2-diphenylethanol.

9. The preparation method according to claim 3, characterized in that, The reaction time is 5 to 1440 min.

10. The preparation method according to claim 3, characterized in that, Includes the following steps: First, stir the urea or thiourea shown in Formula III, the Brønsted base, the solvent, and the initiator, then add the bromine-substituted bridged ring lactone monomer shown in Formula IV to react.

11. The preparation method according to claim 10, characterized in that, The stirring time is 1-8 minutes.

12. The use of the brominated functionalized polyester of claim 1 or 2 or the brominated functionalized polyester prepared by the method of any one of claims 3-10 in the preparation of chemically recyclable materials.

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