Polyester block polymer, preparation method thereof and chemical circulation method of polyester block polymer

Abstract

The invention provides a polyester block polymer, a preparation method thereof and a chemical circulation method of the polyester block polymer. The structural formula of the polyester block polymer is shown in the specification. Blocks in the polyester block polymer can be degraded into polymerization precursors. Meanwhile, the polyester block polymer has better mechanical properties.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of chemically recyclable polymers, in particular to a polyester block polymer and a preparation method thereof, and a chemical recycling method of the polyester block polymer. BACKGROUND

[0002] Polymeric materials are closely related to our production and life, which greatly promotes the development of industry and also facilitates our daily life. However, the pollution problem is also corresponding, a large number of non-degradable plastics, rubbers and other polymeric materials based on petroleum have caused a huge burden to the environment we live in.

[0003] Chemically recyclable polymers as a new type of material can depolymerize into polymer precursors after use, avoiding polymer pollution and providing raw materials for polymer production, which can improve the problem of "white pollution" of plastics. Therefore, in recent years, chemically recyclable polymers have developed rapidly. At present, completely chemically recyclable polymers are obtained by ring-opening homopolymerization of a monomer or ring-opening copolymerization or polycondensation of two monomers, and there is no completely chemically recyclable polymer prepared by two-block polymers, four-block or six-block polymers.

[0004] Block polymers are a kind of materials with rich properties, which can form various morphological polymer materials such as elastomers or plastics according to the composition of the block. Limited monomers can be used to form infinite polymer structures, thereby obtaining polymer materials with adjustable properties. Among them, polyester thermoplastic block polymers are of great concern due to their good biodegradability and biomass sources. Hillmyer et al. prepared a soft segment of poly-ε-caprolactone using p-xylyleneglycol as an initiator, and then prepared a thermoplastic elastomer with excellent mechanical properties by ring-opening polymerization of lactide (Polym. Chem. 2015, 6, 3641-3651). In addition, the research group designed a variety of biomass-derived lactone monomers as soft segments to block copolymerize with lactide to obtain thermoplastic elastomer materials (Macromolecules 2011, 44, 8537-8545; Biomacromolecules 2007, 8, 3634-3640; Proc. Natl. Acad. Sci. U.S.A. 2014, 111, 8357-8362). Recently, the research group of Zhang Yetao obtained a thermoplastic elastomer with high elongation at break and high tensile strength by block copolymerization of copolymer of valerolactone and ε-caprolactone with lactide (CCS Chemistry 2022, 4, 1263-1272). The research group of Li Zhibo also synthesized a triblock copolymer using biobased monomer δ-caprolactone and lactide, which has good mechanical properties and can be degraded by alcoholysis (Angew. Chem. Int. Ed. 2022, 61, e202201407). The research group of William produced a semi-aromatic polyester by ring-opening copolymerization of phthalic anhydride and cyclohexene oxide, which was used as a hard segment to obtain a thermoplastic elastomer with good mechanical properties and alcoholysis (Chem. Sci. 2020, 11, 6567-6581; J. Am. Chem. Soc. 2020, 142, 4367-4378; Macromolecules 2022, 55, 2290-2299).

[0005] However, the reported thermoplastic polymer materials with certain mechanical properties (tensile strength greater than 3 MPa) constructed by block method can only convert the two polymer segments in the block into new small molecule substances (non-polymer precursors) and oligomers by alcoholysis or hydrolysis, and some oligomers are converted into polymer precursors by pyrolysis. Overall, the reported block polymer materials for constructing thermoplastic polymers cannot be completely converted into polymer precursors. It is a very challenging task to obtain chemically recyclable thermoplastic block polymer materials with certain mechanical properties. SUMMARY

[0006] To solve the above technical problems, the present application aims to provide a polyester block polymer, a preparation method thereof, and a chemical recycling method of the polyester block polymer. All blocks in the polyester block polymer can be degraded into polymer precursors. Meanwhile, the polyester block polymer has good mechanical properties.

[0007] To achieve the above-mentioned purposes, the present application provides a polyester block polymer, and a structure formula of the polyester block polymer is as follows:

[0008]

[0009] In the structure formula of the polyester block polymer, y is an integer of 10-10 6 (For example, 20, 50, 100, 1000, 10 4 , 5×10 4 , 1×10 5 , 5×10 5 , 9×10 5 ) integers, x, z, m, n, p are integers of 0-10 6 ;

[0010] When x=m=n=p=0 and z is not equal to 0, the polyester block polymer is a two-block polymer;

[0011] When z=m=n=p=0 and x is not equal to 0, the polyester block polymer is a two-block polymer;

[0012] When z=0, m=0, y=n, and x=p, the polyester block polymer is a four-block polymer;

[0013] When x=p=0, y=n, and m=z, the polyester block polymer is a four-block polymer;

[0014] When x, m, n, p, and z are not equal to 0, z=m, n=y, and x=p, the polyester block polymer is a six-block polymer;

[0015] In the structure formula of the polyester block polymer, the structure of A is shown in formula (I), and the structure of B is shown in formula (II):

[0016]

[0017] In formula (I), R 1 is selected from an alkyl group with 1-20 (for example, 1, 2, 3, 5, 7, 10, 13, 15, 17, 19, or 20) carbon atoms, an aryl group with 6-12 (for example, 6, 8, 10, or 12) carbon atoms, or an alkenyl group with 2-20 (for example, 2, 3, 5, 7, 10, 13, 15, 17, or 19) carbon atoms;

[0018] C is selected from one of the structures shown in formula (III) :

[0019]

[0020] R in formula (III) is selected from one of the structures shown in formula (III) : 3 selected from one of the structures shown in formula (III) :

[0021] R in formula (III) is selected from one of the structures shown in formula (III) : 4 C is selected from one of the structures shown in formula (IV) :

[0022]

[0023] R in formula (IV) is selected from one of the structures shown in formula (IV) : 10 selected from one of the structures shown in formula (IV) :

[0024] R in formula (IV) is selected from one of the structures shown in formula (IV) : 5 C is selected from one of the structures shown in formula (V) :

[0025]

[0026] R in formula (V) is selected from one of the structures shown in formula (V) : 6 C is selected from one of the structures shown in formula (VI) :

[0027]

[0028] R in formula (I) is selected from one of the structures shown in formula (I) : 1 selected from one of the structures shown in formula (I) :

[0029] R in formula (III) is selected from one of the structures shown in formula (III) : 3 selected from one of the structures shown in formula (III) :

[0030] The present application also provides a method for preparing the polyester block polymer as described above, which comprises: using lactone monomers as raw materials, and performing polymerization (ring-opening polymerization) under the action of a catalyst and an initiator; adding water or an acidic substance to terminate the polymerization reaction; adding a second organic solvent to the terminated reaction system to precipitate the polymerization product; and drying the polymerization product to obtain the polyester block polymer; the lactone monomers comprise one monomer 1 having a structure shown in formula (VII) and one monomer 2 having a structure shown in formula (VIII),

[0031]

[0032] R in formula (VII) is selected from one of the structures shown in formula (VII) : 1 selected from one of the structures shown in formula (VII) :

[0033] Further, the method for preparing the polyester block polymer includes: dissolving a mixture of catalyst and initiator in a first organic solvent, stirring at room temperature for 1–10 min (e.g., 2 min, 3 min, 5 min, 7 min, 8 min, 9 min), then adding monomer 1 and polymerizing at -70–80°C (e.g., -68°C, -65°C, -60°C, -50°C, -40°C, -30°C, -20°C, -10°C, 0°C, 10°C, 20°C, 30°C, 40°C, 50°C, 60°C, 70°C, 75°C, 78°C) for 0.1–48 h (e.g., 0.2 h, 0.5 h, 1 h, 3 h, 5 h, 10 h, 15 h, 20 h, 25 h, 30 h, 35 h, 40 h, 45 h). Monomer 2 is added and polymerized at -70 to 80°C (e.g., -68°C, -65°C, -60°C, -50°C, -40°C, -30°C, -20°C, -10°C, 0°C, 10°C, 20°C, 30°C, 40°C, 50°C, 60°C, 70°C, 75°C, 78°C) for 0.1 to 48 hours (e.g., 0.2 hours, 0.5 hours, 1 hour, 3 hours, 5 hours, 10 hours, 15 hours, 20 hours, 25 hours, 30 hours, 35 hours, 40 hours, 45 hours). Water or an acidic substance is then added to terminate the polymerization reaction. A second organic solvent is then added to the terminated reaction system to precipitate the polymer product (by precipitation). The polymer product (i.e., the precipitate) is then filtered, washed, and dried sequentially to obtain the polyester block polymer.

[0034] Preferably, the polymerization reaction temperature is around 15–25°C.

[0035] Furthermore, the catalyst includes one or more of the following: metal catalysts, organic catalysts, and inorganic catalysts.

[0036] The metal catalyst includes rare earth metal compounds and / or transition metal compounds; more preferably, the metal catalyst includes Ln(OCH2C6H5)3, Ln(OR)3, etc. 8 3. Ln(CH2SiMe3)3(THF) d 、Ln[N(SiMe3)2]3、M(OR 9 )2, one or more combinations of M(CH2SiMe3)2 and M[N(SiMe3)2]2, wherein Ln is selected from La, Yb, Sc, Y and Lu; M is selected from Zn and Mg; R 8 R 9 Each is independently selected from hydrocarbon groups with 1 to 20 (e.g., 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 15, 18, 19) carbon atoms; d is 0 to 4.

[0037] The organic catalyst includes an organic base or an organic acid; more preferably, the organic acid is diphenyl phosphate; more preferably, the organic base includes one or more of the following structures:

[0038]

[0039] Among them, R 21 R 22 R 23 Selected from hydrocarbon groups with 1 to 20 carbon atoms (e.g., 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 15, 18, 19), R 21 R 22 R 23 Same or different; R 21 Whether the same or different in different structural formulas, R 22 Whether the same or different in different structural formulas, R 23 The same or different in different structural formulas;

[0040] Among them, the inorganic catalyst is a basic inorganic substance, such as sodium methoxide and sodium ethoxide.

[0041] Furthermore, the initiator comprises one or more of the following structures:

[0042]

[0043] Furthermore, when water or an acidic substance is added to terminate the polymerization reaction, the amount of water or acidic substance added is 1 to 10 times the equivalent of the catalyst (e.g., 1, 3, 5, 8, or 10 times).

[0044] Furthermore, acidic substances include one or more combinations of acetic acid, benzoic acid, hydrochloric acid, sulfuric acid, and phosphoric acid.

[0045] Furthermore, the first organic solvent includes one or more combinations of benzene, toluene, ethylbenzene, hexane, heptane, octane, tetrahydrofuran, diethyl ether, petroleum ether, chloroform, dichloromethane, and N,N-dimethylformamide.

[0046] Furthermore, the second organic solvent includes one or more of hexane, heptane, octane, tetrahydrofuran, diethyl ether, petroleum ether, methanol, and ethanol.

[0047] Furthermore, the polymerization reaction is carried out at a pressure of 1 to 10 atmospheres (e.g., 2 atmospheres, 3 atmospheres, 5 atmospheres, 6 atmospheres, 7 atmospheres, 8 atmospheres, or 9 atmospheres); the polymerization reaction is carried out under the protection of an inert gas atmosphere.

[0048] Furthermore, the molar ratio of catalyst to lactone monomer is 1:10 to 100,000 (e.g., 1:20, 1:50, 1:100, 1:500, 1:1000, 1:10000, 1:50000, 1:100000); the molar ratio of initiator to catalyst is 1 to 100:1 (e.g., 1:1, 10:1, 20:1, 30:1, 40:1, 50:1, 60:1, 70:1, 80:1, 90:1, 95:1, 98:1).

[0049] The present invention also provides a chemical recycling method for the aforementioned polyester block polymer, comprising: mixing the polyester block polymer with an acidic catalyst, and obtaining lactone monomers with the structures shown in formulas (VII) and (VIII) by atmospheric distillation, vacuum sublimation, or vacuum distillation at 40–350°C (e.g., 60°C, 80°C, 100°C, 150°C, 200°C, 250°C, 300°C, 350°C, 370°C, 390°C).

[0050]

[0051] Furthermore, the acidic catalyst includes one or more of zinc chloride, ferrous chloride, ferric chloride, zinc acetate, stannous octoate, and phosphomolybdic acid.

[0052] Furthermore, the acidic catalyst accounts for 0.1% to 50% of the weight of the polyester block polymer (e.g., 0.1%, 1%, 5%, 10%, 15%, 20%, 25%, 30%, 35%, 40%, 45%, 50%).

[0053] All blocks in the polyester block polymer of the present invention can be degraded into polymerization precursors, with a monomer recovery rate greater than 95%. Simultaneously, the recyclable polyester block polymer of the present invention possesses certain mechanical properties (tensile strength greater than 3 MPa), which are attributed to the incompatibility between the substituted valerolactone segments and the unsubstituted valerolactone segments due to polymer substituents. Attached Figure Description

[0054] Figure 1 The diagram shows a comparison of the nuclear magnetic resonance (NMR) spectra of the tetrablock polyester of Example 4 of the present invention and the δ-valerolactone and α-methyl-δ-valerolactone monomers recovered by chemical recycling degradation with the two monomers that form the polymer.

[0055] Figure 2 The mechanical property test diagrams of polyester block polymerization in Examples 1, 4, 6, 7, 8, 20 and 21 of the present invention are shown. Detailed Implementation

[0056] In order to provide a clearer understanding of the technical features, objectives and beneficial effects of the present invention, the technical solution of the present invention will now be described in detail below, but it should not be construed as limiting the scope of implementation of the present invention.

[0057] Example 1

[0058] This embodiment provides a diblock polyester, the structural formula of which is shown below:

[0059]

[0060] The preparation method of this diblock polyester includes the following steps:

[0061] At 20°C, in a pre-dried 25 mL round-bottom flask, 0.02 mmol of the initiator benzyl alcohol was first weighed, and then 10 mmol of the monomer α-methyl-δ-valerolactone was added and stirred for 20 min. Polymerization was initiated by the rapid addition of 0.04 mmol of the catalyst TBD. 1 After confirming that the polymerization had reached equilibrium by ¹H NMR, a toluene solution of 6 mmol δ-valerolactone was added. After a period of time, the polymerization reaction was immediately quenched by adding 5 mL of benzoic acid / CDCl₃ (10 mg / mL), and then... 1 The monomer conversion was determined by ¹H NMR analysis. The quenched mixture was then precipitated in cold methanol, filtered, washed three times with cold methanol to remove any unreacted monomers, and dried overnight at room temperature in a vacuum oven to constant weight. 0.81 g of a white solid was obtained. Gel chromatography determined the polymer's average molecular weight to be 40600 g / mol with a molecular weight distribution of 1.53. DSC analysis showed a melting point of 60 °C, a glass transition temperature of -53 °C, and a tensile strength of 4 MPa.

[0062] Example 2

[0063] This embodiment provides a diblock polyester, the structural formula of which is shown below:

[0064]

[0065] The preparation method of this diblock polyester includes the following steps:

[0066] At 20°C, in a pre-dried 25 mL round-bottom flask, 0.02 mmol of the initiator benzyl alcohol was weighed first, and then 10 mmol of the monomer α-eicosyl-δ-pentanolide was added and stirred for 20 min. Polymerization was initiated by the rapid addition of 0.04 mmol of the catalyst TBD. 1After confirming that the polymerization had reached equilibrium by ¹H NMR, a toluene solution of 6 mmol δ-valerolactone was added. After a period of time, the polymerization reaction was immediately quenched by adding 5 mL of benzoic acid / CDCl₃ (10 mg / mL), and then... 1 The monomer conversion was determined by ¹H NMR analysis. The quenched mixture was then precipitated in cold methanol, filtered, washed three times with cold methanol to remove any unreacted monomers, and dried overnight at room temperature in a vacuum oven to constant weight. 0.91 g of a white solid was obtained. Gel chromatography determined the polymer's average molecular weight to be 60600 g / mol with a molecular weight distribution of 1.63. DSC analysis showed a melting point of 60 °C, a glass transition temperature of -54 °C, and a tensile strength of 5 MPa.

[0067] Example 3

[0068] A diblock polyester, with the following structural formula:

[0069]

[0070] The preparation method of this diblock polyester includes the following steps:

[0071] At 20°C, in a pre-dried 25 mL round-bottom flask, 0.02 mmol of benzyl alcohol as the initiator was first weighed, and 10 mmol of α-phenyl-δ-valerolactone monomer was added and stirred for 20 min. Polymerization was initiated by the rapid addition of 0.04 mmol of TBD catalyst. After confirming that the polymerization had reached equilibrium by 1H NMR, a toluene solution of 6 mmol of δ-valerolactone was added. After a period of time, the polymerization reaction was immediately quenched by adding 5 mL of benzoic acid / CDCl3 (10 mg / mL), and then... 1 The monomer conversion was determined by ¹H NMR analysis. The quenched mixture was then precipitated in cold methanol, filtered, washed three times with cold methanol to remove any unreacted monomers, and dried overnight at room temperature in a vacuum oven to constant weight. 0.76 g of a white solid was obtained. Gel chromatography determined the average molecular weight of the polymer to be 50600 g / mol with a molecular weight distribution of 1.73. DSC analysis showed the polymer melting point to be 60 °C and the tensile strength to be 10 MPa.

[0072] Example 4

[0073] A tetrablock polyester, with the following structural formula:

[0074]

[0075] The preparation method of this tetrablock polyester includes the following steps:

[0076] At 20°C, in a pre-dried 25 mL round-bottom flask, 0.02 mmol of the initiator 1,4-phenylenediol (BDM) was first weighed, and 10 mmol of the monomer α-methyl-δ-valerolactone was added. The mixture was stirred for 20 min, and after the BDM was completely dissolved, 2.5 mL of toluene was added. Polymerization was initiated by the rapid addition of 0.04 mmol of the catalyst TBD. 1 After confirming that the polymerization had reached equilibrium by ¹H NMR, a toluene solution of 6 mmol δ-valerolactone was added. After a period of time, the polymerization reaction was immediately quenched by adding 5 mL of benzoic acid / CDCl₃ (10 mg / mL), and then... 1 The monomer conversion was determined by ¹H NMR analysis. The quenched mixture was then precipitated in cold methanol, filtered, washed three times with cold methanol to remove any unreacted monomers, and dried overnight at room temperature in a vacuum oven to constant weight. 1.40 g of a white solid was obtained. Gel chromatography determined the polymer's average molecular weight to be 80600 g / mol with a molecular weight distribution of 1.53. DSC analysis showed a melting point of 60 °C, a glass transition temperature of -53 °C, and a tensile strength of 23 MPa.

[0077] Example 5

[0078] Using the same experimental apparatus and under the same conditions as in Example 4, the temperature was lowered to -10°C. 1 After confirming that the polymerization had reached equilibrium by 1H NMR, a toluene solution of 6 mmol δ-valerolactone was added. After a period of time, the polymerization reaction was immediately quenched by adding 5 mL of benzoic acid / CDCl3 (10 mg / mL), and then analyzed by 1H NMR to obtain the monomer conversion. The quenched mixture was then precipitated in cold methanol, filtered, washed three times with cold methanol to remove any unreacted monomers, and dried overnight at room temperature in a vacuum drying oven to constant weight. 1.43 g of a white solid was obtained. The average molecular weight of the polymer was determined to be 87700 g / mol by gel permeation chromatography, with a molecular weight distribution of 1.44. DSC analysis showed that the polymer had a melting point of 60 °C, a glass transition temperature of -53 °C, and a tensile strength of 12 MPa.

[0079] Example 6

[0080] Using the same experimental apparatus and under the same conditions as in Example 4, only the solvent was changed to tetrahydrofuran. 1 After confirming that the polymerization had reached equilibrium by ¹H NMR, 6 mmol of a tetrahydrofuran solution of δ-valerolactone was added. After a period of time, the polymerization reaction was immediately quenched by adding 5 mL of benzoic acid / CDCl₃ (10 mg / mL), and then... 1The monomer conversion was determined by ¹H NMR analysis. The quenched mixture was then precipitated in cold methanol, filtered, washed three times with cold methanol to remove any unreacted monomers, and dried overnight in a vacuum oven at room temperature to constant weight. 1.38 g of a white solid was obtained. Gel chromatography determined the polymer's average molecular weight to be 81900 g / mol with a molecular weight distribution of 1.37. DSC analysis showed a melting point of 60 °C, a glass transition temperature of -53 °C, and a tensile strength of 10 MPa.

[0081] Example 7

[0082] Using the same experimental apparatus and under the same conditions as in Example 4, except that the initiator was replaced with ethylene glycol. 1 After confirming that the polymerization had reached equilibrium by ¹H NMR, a tetrahydrofuran solution of δ-valerolactone was added. After a period of time, 5 mL of benzoic acid / CDC was added. l3 (10 mg / mL) Immediately quench the polymerization reaction, then use 1 The monomer conversion was determined by ¹H NMR analysis. The quenched mixture was then precipitated in cold methanol, filtered, washed three times with cold methanol to remove any unreacted monomers, and dried overnight in a vacuum oven at room temperature to constant weight. 1.38 g of a white solid was obtained. Gel chromatography determined the polymer's average molecular weight to be 79900 g / mol with a molecular weight distribution of 1.47. DSC analysis showed a melting point of 60 °C, a glass transition temperature of -53 °C, and a tensile strength of 10 MPa.

[0083] Example 8

[0084] This embodiment provides a tetrablock polyester, with the following structural formula:

[0085]

[0086] Using the same experimental apparatus and under the same conditions as in Example 4, except that the initiator was replaced with pentaerythritol. 1 After confirming that the polymerization had reached equilibrium by ¹H NMR, a toluene solution of 6 mmol δ-valerolactone was added. After a period of time, the polymerization reaction was immediately quenched by adding 5 mL of benzoic acid / CDCl₃ (10 mg / mL), and then... 1 The monomer conversion was determined by ¹H NMR analysis. The quenched mixture was then precipitated in cold methanol, filtered, washed three times with cold methanol to remove any unreacted monomers, and dried overnight in a vacuum oven at room temperature to constant weight. 1.40 g of a white solid was obtained. Gel chromatography determined the polymer's average molecular weight to be 109300 g / mol with a molecular weight distribution of 1.63. DSC analysis showed a melting point of 59 °C, a glass transition temperature of -54 °C, and a tensile strength of 14 MPa.

[0087] Example 9

[0088] Using the same experimental apparatus and under the same conditions as in Example 4, except that the catalyst was replaced with diphenyl phosphate. 1 After confirming that the polymerization had reached equilibrium by ¹H NMR, a toluene solution of 6 mmol δ-valerolactone was added. After a period of time, the polymerization reaction was immediately quenched by adding 5 mL of benzoic acid / CDCl₃ (10 mg / mL), and then... 1 The monomer conversion was determined by ¹H NMR analysis. The quenched mixture was then precipitated in cold methanol, filtered, washed three times with cold methanol to remove any unreacted monomers, and dried overnight in a vacuum oven at room temperature to a constant weight. 1.40 g of a white solid was obtained. Gel chromatography determined the polymer's average molecular weight to be 83300 g / mol with a molecular weight distribution of 1.53. DSC analysis showed a melting point of 60 °C, a glass transition temperature of -53 °C, and a tensile strength of 14 MPa.

[0089] Example 10

[0090] Using the same experimental apparatus and conditions as in Example 4, except that the catalyst was replaced with Ln[N(SiMe3)2]. After confirming that the polymerization had reached equilibrium by 1H NMR, a toluene solution of 6 mmol δ-valerolactone was added. After a period of time, the polymerization reaction was immediately quenched by adding 5 mL of benzoic acid / CDCl3 (10 mg / mL), and then... 1 The monomer conversion was determined by ¹H NMR analysis. The quenched mixture was then precipitated in cold methanol, filtered, washed three times with cold methanol to remove any unreacted monomers, and dried overnight in a vacuum oven at room temperature to constant weight. 1.40 g of a white solid was obtained. Gel chromatography determined the polymer's average molecular weight to be 82400 g / mol with a molecular weight distribution of 1.63. DSC analysis showed a melting point of 60 °C, a glass transition temperature of -53 °C, and a tensile strength of 13 MPa.

[0091] Example 11

[0092] This embodiment provides a tetrablock polyester, with the following structural formula:

[0093]

[0094] The preparation method of this tetrablock polyester includes the following steps:

[0095] At 20°C, in a pre-dried 25 mL round-bottom flask, 0.02 mmol of the initiator 1,4-phenylenediol (BDM) was first weighed, and 10 mmol of the monomer α-ethyl-δ-valerol was added. The mixture was stirred for 20 min, and after the BDM was completely dissolved, 2.5 mL of toluene was added. Polymerization was initiated by the rapid addition of 0.04 mmol of the catalyst TBD. 1 After confirming that the polymerization had reached equilibrium by ¹H NMR, a toluene solution of 6 mmol δ-valerolactone was added. After a period of time, the polymerization reaction was immediately quenched by adding 5 mL of benzoic acid / CDCl₃ (10 mg / mL), and then... 1 The monomer conversion was determined by ¹H NMR analysis. The quenched mixture was then precipitated in cold methanol, filtered, washed three times with cold methanol to remove any unreacted monomers, and dried overnight in a vacuum oven at room temperature to constant weight. 1.51 g of a white solid was obtained. Gel chromatography determined the polymer's average molecular weight to be 89600 g / mol with a molecular weight distribution of 1.46. DSC analysis showed a melting point of 59 °C, a glass transition temperature of -50 °C, and a tensile strength of 15 MPa.

[0096] Example 12

[0097] This embodiment provides a tetrablock polyester, with the following structural formula:

[0098]

[0099] The preparation method of this tetrablock polyester includes the following steps:

[0100] At 20°C, in a pre-dried 25 mL round-bottom flask, 0.02 mmol of the initiator 1,4-phenylenediol (BDM) was first weighed, and 10 mmol of the monomer α-octyl-δ-valerolactone was added. The mixture was stirred for 20 min, and after the BDM was completely dissolved, 2.5 mL of toluene was added. Polymerization was initiated by the rapid addition of 0.04 mmol of the catalyst TBD. 1 After confirming that the polymerization had reached equilibrium by ¹H NMR, a toluene solution of 6 mmol δ-valerolactone was added. After a period of time, the polymerization reaction was immediately quenched by adding 5 mL of benzoic acid / CDCl₃ (10 mg / mL), and then... 1 The monomer conversion was determined by ¹H NMR analysis. The quenched mixture was then precipitated in cold methanol, filtered, washed three times with cold methanol to remove any unreacted monomers, and dried overnight in a vacuum oven at room temperature to a constant weight. 1.82 g of a white solid was obtained. Gel chromatography determined the polymer's average molecular weight to be 128,600 g / mol with a molecular weight distribution of 1.42. DSC analysis showed a melting point of 61 °C, a glass transition temperature of -55 °C, and a tensile strength of 15 MPa.

[0101] Example 13

[0102] This embodiment provides a tetrablock polyester, with the following structural formula:

[0103]

[0104] The preparation method of this tetrablock polyester includes the following steps:

[0105] At 20°C, in a pre-dried 25 mL round-bottom flask, 0.02 mmol of the initiator 1,4-phenylenediol (BDM) was first weighed, and 10 mmol of the monomer α-eicosanoyl-δ-pentanolide was added. The mixture was stirred for 20 min, and after the BDM was completely dissolved, 2.5 mL of toluene was added. Polymerization was initiated by the rapid addition of 0.04 mmol of the catalyst TBD. 1 After confirming that the polymerization had reached equilibrium by ¹H NMR, a toluene solution of 6 mmol δ-valerolactone was added. After a period of time, the polymerization reaction was immediately quenched by adding 5 mL of benzoic acid / CDCl₃ (10 mg / mL), and then... 1 The monomer conversion was determined by ¹H NMR analysis. The quenched mixture was then precipitated in cold methanol, filtered, washed three times with cold methanol to remove any unreacted monomers, and dried overnight in a vacuum oven at room temperature to constant weight. 1.58 g of a white solid was obtained. Gel chromatography determined the polymer's average molecular weight to be 97600 g / mol with a molecular weight distribution of 1.56. DSC analysis showed a melting point of 60 °C, a glass transition temperature of -52 °C, and a tensile strength of 16 MPa.

[0106] Example 14

[0107] This embodiment provides a tetrablock polyester, with the following structural formula:

[0108]

[0109] The preparation method of this tetrablock polyester includes the following steps:

[0110] At 20°C, in a pre-dried 25 mL round-bottom flask, 0.02 mmol of the initiator 1,4-phenylenediol (BDM) was first weighed, and 10 mmol of the monomer α-phenyl-δ-valerol was added. The mixture was stirred for 20 min, and after the BDM was completely dissolved, 2.5 mL of toluene was added. Polymerization was initiated by the rapid addition of 0.04 mmol of the catalyst TBD. 1 After confirming that the polymerization had reached equilibrium by ¹H NMR, a toluene solution of 6 mmol δ-valerolactone was added. After a period of time, the polymerization reaction was immediately quenched by adding 5 mL of benzoic acid / CDCl₃ (10 mg / mL), and then...1 The monomer conversion was determined by ¹H NMR analysis. The quenched mixture was then precipitated in cold methanol, filtered, washed three times with cold methanol to remove any unreacted monomers, and dried overnight in a vacuum oven at room temperature to constant weight. 1.62 g of a white solid was obtained. Gel chromatography determined the polymer's average molecular weight to be 104600 g / mol with a molecular weight distribution of 1.46. DSC analysis showed a melting point of 60 °C and a tensile strength of 15 MPa.

[0111] Example 15

[0112] This embodiment provides a tetrablock polyester, with the following structural formula:

[0113]

[0114] The preparation method of this tetrablock polyester includes the following steps:

[0115] At 20°C, in a pre-dried 25 mL round-bottom flask, 0.02 mmol of the initiator 1,4-terephthalic acid (BDM) was first weighed, and 10 mmol of the monomer α-benzyl-δ-valerolactone was added. The mixture was stirred for 20 min, and after the BDM was completely dissolved, 2.5 mL of toluene was added. Polymerization was initiated by the rapid addition of 0.04 mmol of the catalyst TBD. 1 After confirming that the polymerization had reached equilibrium by ¹H NMR, a toluene solution of 6 mmol δ-valerolactone was added. After a period of time, the polymerization reaction was immediately quenched by adding 5 mL of benzoic acid / CDCl₃ (10 mg / mL), and then... 1 The monomer conversion was determined by ¹H NMR analysis. The quenched mixture was then precipitated in cold methanol, filtered, washed three times with cold methanol to remove any unreacted monomers, and dried overnight in a vacuum oven at room temperature to constant weight. 1.69 g of a white solid was obtained. Gel chromatography determined the average molecular weight of the polymer to be 109,600 g / mol with a molecular weight distribution of 1.42. DSC analysis showed a melting point of 61 °C and a tensile strength of 15 MPa.

[0116] Example 16

[0117] This embodiment provides a tetrablock polyester, with the following structural formula:

[0118]

[0119] The preparation method of this tetrablock polyester includes the following steps:

[0120] At 20°C, in a pre-dried 25 mL round-bottom flask, 0.02 mmol of the initiator 1,4-phenylenediol (BDM) was first weighed, and 10 mmol of the monomer α-(6-phenyl-hexyl)-δ-pentanolide was added. The mixture was stirred for 20 min, and after the BDM was completely dissolved, 2.5 mL of toluene was added. Polymerization was initiated by the rapid addition of 0.04 mmol of the catalyst TBD. 1 After confirming that the polymerization had reached equilibrium by ¹H NMR, a toluene solution of 6 mmol δ-valerolactone was added. After a period of time, the polymerization reaction was immediately quenched by adding 5 mL of benzoic acid / CDCl₃ (10 mg / mL), and then... 1 The monomer conversion was determined by ¹H NMR analysis. The quenched mixture was then precipitated in cold methanol, filtered, washed three times with cold methanol to remove any unreacted monomers, and dried overnight in a vacuum oven at room temperature to constant weight. 1.75 g of a white solid was obtained. Gel chromatography determined the average molecular weight of the polymer to be 115600 g / mol with a molecular weight distribution of 1.45. DSC analysis showed the polymer melting point to be 60 °C and the tensile strength to be 12 MPa.

[0121] Example 17

[0122] This embodiment provides a tetrablock polyester, with the following structural formula:

[0123]

[0124] The preparation method of this tetrablock polyester includes the following steps:

[0125] At 20°C, in a pre-dried 25 mL round-bottom flask, 0.02 mmol of the initiator 1,4-phenylenediol (BDM) was first weighed, and 10 mmol of the monomer α-vinyl-δ-valerolactone was added. The mixture was stirred for 20 min, and after the BDM was completely dissolved, 2.5 mL of toluene was added. Polymerization was initiated by the rapid addition of 0.04 mmol of the catalyst TBD. 1 After confirming that the polymerization had reached equilibrium by ¹H NMR, a toluene solution of 6 mmol δ-valerolactone was added. After a period of time, the polymerization reaction was immediately quenched by adding 5 mL of benzoic acid / CDCl₃ (10 mg / mL), and then... 1 The monomer conversion was determined by ¹H NMR analysis. The quenched mixture was then precipitated in cold methanol, filtered, washed three times with cold methanol to remove any unreacted monomers, and dried overnight in a vacuum oven at room temperature to constant weight. 1.77 g of a white solid was obtained. Gel chromatography determined the average molecular weight of the polymer to be 118,600 g / mol with a molecular weight distribution of 1.41. DSC analysis showed a melting point of 62 °C and a tensile strength of 16 MPa.

[0126] Example 18

[0127] This embodiment provides a tetrablock polyester, with the following structural formula:

[0128]

[0129] The preparation method of this tetrablock polyester includes the following steps:

[0130] At 20°C, in a pre-dried 25 mL round-bottom flask, 0.02 mmol of the initiator 1,4-terephthalic acid (BDM) was first weighed, and 10 mmol of the monomer α-allyl-δ-valerol was added. The mixture was stirred for 20 min, and after the BDM was completely dissolved, 2.5 mL of toluene was added. Polymerization was initiated by the rapid addition of 0.04 mmol of the catalyst TBD. 1 After confirming that the polymerization had reached equilibrium by ¹H NMR, a toluene solution of 6 mmol δ-valerolactone was added. After a period of time, the polymerization reaction was immediately quenched by adding 5 mL of benzoic acid / CDCl₃ (10 mg / mL), and then... 1 The monomer conversion was determined by ¹H NMR analysis. The quenched mixture was then precipitated in cold methanol, filtered, washed three times with cold methanol to remove any unreacted monomers, and dried overnight in a vacuum oven at room temperature to constant weight. 1.77 g of a white solid was obtained. Gel chromatography determined the average molecular weight of the polymer to be 128,600 g / mol with a molecular weight distribution of 1.51. DSC analysis showed a melting point of 62 °C and a tensile strength of 16 MPa.

[0131] Example 19

[0132] This embodiment provides a tetrablock polyester, with the following structural formula:

[0133]

[0134] The preparation method of this tetrablock polyester includes the following steps:

[0135] Polymerization was carried out at 20°C in a pre-dried 25 mL round-bottom flask. First, 0.02 mmol of the initiator 1,4-phenylenediol (BDM) was weighed, and 10 mmol of the monomer α-(19-eneicosyl)-δ-pentanolide was added. The mixture was stirred for 20 min until the BDM was completely dissolved, and then 2.5 mL of toluene was added. Polymerization was initiated by the rapid addition of 0.04 mmol of the catalyst TBD. 1 After confirming that the polymerization had reached equilibrium by ¹H NMR, a toluene solution of 6 mmol δ-valerolactone was added. After a period of time, the polymerization reaction was immediately quenched by adding 5 mL of benzoic acid / CDCl₃ (10 mg / mL), and then... 1The monomer conversion was determined by ¹H NMR analysis. The quenched mixture was then precipitated in cold methanol, filtered, washed three times with cold methanol to remove any unreacted monomers, and dried overnight in a vacuum oven at room temperature to constant weight. 1.77 g of a white solid was obtained. Gel chromatography determined the average molecular weight of the polymer to be 155,700 g / mol with a molecular weight distribution of 1.61. DSC analysis showed a melting point of 62 °C and a tensile strength of 12 MPa.

[0136] Example 20

[0137] This embodiment provides a hexablock polyester, with the following structural formula:

[0138]

[0139] The preparation method of this hexablock polyester includes the following steps:

[0140] At 20°C, in a pre-dried 25 mL round-bottom flask, 0.02 mmol of the initiator 1,4-phenylenediol (BDM) was first weighed, and 10 mmol of the monomer δ-valerolactone was added. The mixture was stirred for 20 min, and after the BDM was completely dissolved, 2.5 mL of toluene was added. Polymerization was initiated by the rapid addition of 0.04 mmol of the catalyst TBD. 1 After confirming that the polymerization had reached equilibrium by HNMR, a toluene solution of 6 mmol of α-methyl-δ-valerolactone was added. 1 After confirming that the polymerization had reached equilibrium by ¹H NMR, a toluene solution of 6 mmol δ-valerolactone was added. After a period of time, the polymerization reaction was immediately quenched by adding 5 mL of benzoic acid / CDCl₃ (10 mg / mL), and then... 1 The monomer conversion was determined by ¹H NMR analysis. The quenched mixture was then precipitated in cold methanol, filtered, washed three times with cold methanol to remove any unreacted monomers, and dried overnight at room temperature in a vacuum oven to constant weight. 1.60 g of a white solid was obtained. Gel chromatography determined the polymer's average molecular weight to be 124,500 g / mol, with a molecular weight distribution of 1.64, and a tensile strength of 15 MPa.

[0141] Example 21

[0142] This embodiment provides a hexablock polyester, with the following structural formula:

[0143]

[0144] The preparation method of this hexablock polyester includes the following steps:

[0145] At 20°C, in a pre-dried 25 mL round-bottom flask, 0.02 mmol of the initiator 1,4-phenylenediol (BDM) was first weighed, and 10 mmol of the monomer δ-valerolactone was added. The mixture was stirred for 20 min, and after the BDM was completely dissolved, 2.5 mL of toluene was added. Polymerization was initiated by the rapid addition of 0.04 mmol of the catalyst TBD. 1 After confirming that the polymerization had reached equilibrium by HNMR, a toluene solution of 6 mmol of α-eicosyl-δ-pentanolide was added. 1 After confirming that the polymerization had reached equilibrium by ¹H NMR, a toluene solution of 6 mmol δ-valerolactone was added. After a period of time, the polymerization reaction was immediately quenched by adding 5 mL of benzoic acid / CDCl₃ (10 mg / mL), and then... 1 The monomer conversion was determined by ¹H NMR analysis. The quenched mixture was then precipitated in cold methanol, filtered, washed three times with cold methanol to remove any unreacted monomers, and dried overnight at room temperature in a vacuum oven to constant weight. 1.60 g of a white solid was obtained. Gel chromatography determined the polymer's average molecular weight to be 114,500 g / mol, with a molecular weight distribution of 1.63 and a tensile strength of 30 MPa. Figure 2 The mechanical property test diagrams of the polymers formed in Examples 1, 4, 6, 7, 8, 20 and 21 of the present invention are shown.

[0146] Example 22

[0147] 0.5 g of the polymer obtained in Example 1 was added to a stainless steel autoclave and placed in a muffle furnace preheated to 300 °C. After 1 hour, the autoclave was removed to obtain 0.49 g of α-methyl-δ-valerolactone and δ-valerolactone monomer. Gas chromatography determined its purity to be greater than 99%.

[0148] Example 23

[0149] 0.5 g of the polymer obtained in Example 2 was added to a stainless steel autoclave and placed in a muffle furnace preheated to 340 °C. After 1 hour, the autoclave was removed to obtain 0.49 g of α-eicosyl-δ-valerolactone and δ-valerolactone monomer. Gas chromatography determined its purity to be greater than 99%.

[0150] Example 24

[0151] 0.5 g of the polymer obtained in Example 3 was added to a stainless steel autoclave and placed in a muffle furnace preheated to 340 °C. After 1 hour, the autoclave was removed to obtain 0.49 g of α-phenyl-δ-valerolactone and δ-valerolactone monomer. Gas chromatography determined its purity to be greater than 99%.

[0152] Example 25

[0153] 1 g of the tetrablock polymer obtained in Example 4 was added to a sublimator, along with 10 mg of zinc chloride. The mixture was kept under vacuum of 0.07 torr and at 180°C to obtain 0.99 g of a mixture of α-methyl-δ-valerolactone and δ-valerolactone. Gas chromatography determined the purity of both to be greater than 99%. Figure 1 The diagram shows a comparison of the nuclear magnetic resonance (NMR) images of the tetrablock polyester of Example 4 of the present invention and the δ-valerolactone and α-methyl-δ-valerolactone monomers recovered by chemical recycling degradation with the two monomers that form the polymer.

[0154] Example 26

[0155] 1 g of the tetrablock polymer obtained in Example 8 was added to a sublimator, along with 10 mg of zinc chloride. The mixture was kept under vacuum of 0.07 torr and at 180°C to obtain 0.98 g of a mixture of α-methyl-δ-valerolactone and δ-valerolactone. Gas chromatography determined the purity of both to be greater than 99%.

[0156] Example 27

[0157] 1 g of the block polymer obtained in Example 11 was added to a sublimator, along with 10 mg of zinc chloride. The mixture was kept under vacuum of 0.07 torr and at 180°C to obtain 0.99 g of a mixture of α-ethyl-δ-valerolactone and δ-valerolactone. Gas chromatography determined the purity of both to be greater than 99%.

[0158] Example 28

[0159] 1 g of the block polymer obtained in Example 12 was added to a sublimator, followed by 10 mg of zinc chloride. The mixture was kept under vacuum of 0.06 torr and at 180°C to obtain 0.99 g of a mixture of α-octyl-δ-valerolactone and δ-valerolactone. Gas chromatography determined the purity of both to be greater than 99%.

[0160] Example 29

[0161] 1 g of the block polymer obtained in Example 13 was added to a sublimator, along with 10 mg of zinc chloride. The mixture was kept under vacuum of 0.09 torr and at 200°C to obtain 0.99 g of a mixture of α-eicosyl-δ-valerolactone and δ-valerolactone. Gas chromatography determined the purity of both to be greater than 99%.

[0162] Example 30

[0163] 1 g of the block polymer obtained in Example 14 was added to a sublimator, along with 10 mg of zinc chloride. The mixture was kept under vacuum of 0.07 torr and at 220°C to obtain 0.98 g of a mixture of α-phenyl-δ-valerolactone and δ-valerolactone. Gas chromatography determined the purity of both to be greater than 99%.

[0164] Example 31

[0165] 1 g of the block polymer obtained in Example 15 was added to a sublimator, along with 10 mg of zinc chloride. The mixture was kept under vacuum of 0.07 torr and at 170°C to obtain 0.99 g of a mixture of α-benzyl-δ-valerolactone and δ-valerolactone. Gas chromatography determined the purity of both to be greater than 99%.

[0166] Example 32

[0167] 1 g of the block polymer obtained in Example 16 was added to a sublimator, along with 10 mg of zinc chloride. The mixture was kept under vacuum of 0.07 torr and at 190°C to obtain 0.97 g of a mixture of α-(6-phenyl-hexyl)-δ-valerolactone and δ-valerolactone. Gas chromatography determined the purity of both to be greater than 99%.

[0168] Example 33

[0169] 1 g of the block polymer obtained in Example 17 was added to a sublimator, along with 10 mg of zinc chloride. The mixture was kept under vacuum of 0.07 torr and at 160°C to obtain 0.97 g of a mixture of α-vinyl-δ-valerolactone and δ-valerolactone. Gas chromatography determined the purity of both to be greater than 99%.

[0170] Example 34

[0171] 1 g of the block polymer obtained in Example 18 was added to a sublimator, along with 10 mg of zinc chloride. The mixture was kept under vacuum of 0.07 torr and at 160°C to obtain 0.97 g of a mixture of α-allyl-δ-valerolactone and δ-valerolactone. Gas chromatography determined the purity of both to be greater than 99%.

[0172] Example 35

[0173] 1 g of the block polymer obtained in Example 19 was added to a sublimator, followed by 10 mg of zinc chloride. The mixture was kept under vacuum of 0.07 torr and at 200°C to obtain 0.97 g of a mixture of α-(19-eneicosyl)-δ-pentanolide and δ-pentanolide. Gas chromatography determined the purity of both to be greater than 99%.

[0174] Example 36

[0175] 1 g of the block polymer obtained in Example 20 was added to a sublimator, along with 10 mg of phosphomolybdic acid. The mixture was kept under vacuum of 0.07 torr and at 200°C to obtain 0.97 g of a mixture of δ-valerolactone and α-methyl-δ-valerolactone. Gas chromatography determined the purity of both to be greater than 99%.

[0176] Example 37

[0177] 1 g of the block polymer obtained in Example 21 was added to a sublimator, along with 10 mg of phosphomolybdic acid. The mixture was kept under vacuum of 0.07 torr and at 180°C to obtain 0.97 g of a mixture of δ-valerolactone and α-eicosyl-δ-valerolactone. Gas chromatography determined the purity of both mixtures to be greater than 99%.

Claims

1. A polyester block polymer, wherein, The polyester block polymer has a structure formula as follows: The structural formula of the polyester block polymer is: y is an integer of 10-10 6 x, z, m, n, p are integers of 0-10 6 ​ When x=m=n=p=0, and z is not equal to 0, the polyester block polymer is a two-block polymer; When z=m=n=p=0, and x is not equal to 0, the polyester block polymer is a two-block polymer; When z=0, m=0, y=n, and x=p, the polyester block polymer is a four-block polymer; When x=p=0, y=n, and m=z, the polyester block polymer is a four-block polymer; When x, m, n, p, and z are not equal to 0, z=m, n=y, and x=p, the polyester block polymer is a six-block polymer; In the structure formula of the polyester block polymer, the structure of A is shown in formula (I), and the structure of B is shown in formula (II): In formula (I), R 1 is selected from alkyl of 1 to 20 carbon atoms, aryl of 6 to 12 carbon atoms or alkenyl of 2 to 20 carbon atoms; In the structure formula of the polyester block polymer, C is selected from one of the structures shown in formula (III): In formula (III), R 3 is selected from a hydrocarbon group of 1 to 20 carbon atoms or an aryl group of 6 to 12 carbon atoms; R 4 C corresponds to one of the structures as shown in formula (IV): In formula (IV), R 10 is an alkyl group having from 1 to 20 carbon atoms, u is an integer selected from 1 to 3, and w is an integer selected from 1 to 3. R 5 C corresponds to one of the structures shown as formula (V): R 6 C corresponds to a structure selected from the group consisting of formula (VI):

2. The polyester block polymer of claim 1, wherein, In formula (I), R 1 is selected from alkyl groups of 1 to 20 carbon atoms.

3. The polyester block polymer of claim 1, wherein, In formula (III), R 3 is selected from hydrocarbyl groups of 1 to 20 carbon atoms.

4. A process for the preparation of the polyester block polymer of any one of claims 1 to 3, wherein, The polyester block polymer is prepared by the following steps: Polymerization is carried out under the action of a catalyst and an initiator, and water or an acidic substance is added to terminate the polymerization reaction; A second organic solvent is added to the terminated reaction system to precipitate a polymerization product, and the polymerization product is dried to obtain the polyester block polymer; The lactone monomer includes a monomer 1 having a structure shown in formula (VII) and a monomer 2 having a structure shown in formula (VIII), in which R is selected from alkyl of 1 to 20 carbon atoms, aryl of 6 to 12 carbon atoms or alkenyl of 2 to 20 carbon atoms. 1 in which R is selected from alkyl of 1 to 20 carbon atoms, aryl of 6 to 12 carbon atoms or alkenyl of 2 to 20 carbon atoms.

5. The method of making a polyester block polymer according to claim 4, wherein, The polyester block polymer is prepared by the following steps: The mixture of the catalyst and the initiator is dissolved in a first organic solvent, and the monomer 1 is polymerized at -70-80 ℃ for 0.1-48 h, and then the monomer 2 is polymerized at -70-80 ℃ for 0.1-48 h, and then the water or the acidic substance is added to terminate the polymerization reaction, and then the second organic solvent is added to the terminated reaction system to precipitate the polymerization product, and the polymerization product is sequentially filtered, washed, and dried to obtain the polyester block polymer.

6. The method of making a polyester block polymer according to claim 4, wherein, The catalyst includes one or a combination of two or more of a metal catalyst, an organic catalyst, and an inorganic catalyst; The metal catalyst includes a rare earth metal compound and / or a transition metal compound; The organic catalyst includes an organic base or an organic acid; the organic acid is diphenyl phosphate; and the organic base includes one or a combination of two or more of the following structures: wherein R 21 , R 22 , R 23 are selected from hydrocarbyl groups of 1 to 20 carbon atoms, R 21 , R 22 , R 23 are the same or different; R 21 are the same or different in different structural formulas, R 22 are the same or different in different structural formulas, R 23 are the same or different in different structural formulas; The inorganic catalyst is an alkaline inorganic substance.

7. The method of making a polyester block polymer according to claim 4, wherein, The initiator includes one or a combination of two or more of the following structures:

8. The method of making a polyester block polymer according to claim 4, wherein, When the water or the acidic substance is added to terminate the polymerization reaction, the amount of the water or the acidic substance added is 1-10 times the equivalent of the catalyst.

9. The method of making a polyester block polymer according to claim 4, wherein, The acidic substance includes one or a combination of two or more of acetic acid, benzoic acid, hydrochloric acid, sulfuric acid, and phosphoric acid.

10. The method of making a polyester block polymer according to claim 4, wherein, The second organic solvent includes one or a combination of two or more of hexane, heptane, octane, tetrahydrofuran, diethyl ether, petroleum ether, methanol, and ethanol.

11. The method of making a polyester block polymer according to claim 4, wherein, The molar ratio of the catalyst to the lactone monomer is 1:10-100,000; and the molar ratio of the initiator to the catalyst is 1-100:

1.

12. A method of chemical recycling of the polyester block polymer of any one of claims 1 to 3, wherein, The polyester block polymer is mixed with an acidic catalyst, and lactone monomers having structures shown in formula (VII) and formula (VIII) are obtained by atmospheric distillation, vacuum sublimation, or vacuum distillation at a temperature of 40-350 ℃: ​ 13. The chemical recycling process of a polyester block polymer according to claim 12, wherein, The acid catalyst includes one or a combination of two or more of zinc chloride, ferrous chloride, ferric chloride, zinc acetate, stannous octoate, and phosphomolybdic acid.

14. The chemical recycling process of a polyester block polymer according to claim 12, wherein, The acid catalyst comprises 0.1 to 50% by weight of the polyester block polymer.

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