Monomolecular bifunctional organic catalyst for ring-opening copolymerization of epoxide and cyclic anhydride as well as preparation method and application of monomolecular bifunctional organic catalyst

Abstract

The invention discloses a monomolecular bifunctional organic catalyst for ring-opening copolymerization of epoxide and cyclic anhydride. The structural formula of the monomolecular bifunctional organic catalyst is shown as a formula (I). In the formula (I), the structural formula of X is shown as the following formula (II-1) or (II-2), and in the formula, B is a boron atom; r1 is selected from alkyl; # imgabs0 # represents a connecting bond; the structural formula of Y is as shown in the following formula (III), wherein O is an oxygen atom; r2 is selected from one or more of Li, Na, K, Cs, quaternary ammonium cations and bis (triphenylphosphine) ammonium cations; l is selected from the group consisting of unsubstituted C4-C11 alkyl groups; the monomolecular bifunctional organic catalyst disclosed by the invention is specially used for the ring-opening copolymerization reaction of epoxide and cyclic anhydride, the TOF of the monomolecular bifunctional organic catalyst can be up to 13500h, and the prepared polymer has high molecular weight and low molecular weight distribution and also shows excellent air stability and thermal stability. # imgabs1 # (I); # imgabs2 # (II-1); 3 # imgabs3 # (II-2); and 4 # imgabs4 # (III).

Description

Technical Field

[0001] The present invention relates to the technical field of polymers, and particularly to a single-molecule bifunctional organic catalyst for ring-opening copolymerization of epoxides and cyclic anhydrides, and a preparation method and application thereof. Background Art

[0002] In the past four decades, organometallic chemists have developed a variety of metal complexes through extensive research. These complexes exhibit excellent activity and controllability in the copolymerization reaction of epoxides / anhydrides through a coordination-insertion mechanism. However, the pollution problems caused by metal residues (including high purification costs and restrictions on residual metals in food packaging and biomedical material applications) have prompted researchers to explore new catalytic systems. As the third major catalytic paradigm after enzyme catalysis and metal catalysis, organocatalysis has attracted much attention due to its advantages such as low toxicity, environmental friendliness, and easy accessibility.

[0003] In 2016, Gnanou, Feng Xiaoshuang et al. creatively developed a binary organocatalytic system composed of alkyl borane and onium salt, and for the first time achieved high-activity and high-selectivity copolymerization of epoxides and CO 2 Thereafter, the boron-based bifunctional organocatalytic system has shown remarkable generality in the (co)polymerization of epoxides and oxygen-containing monomers (including cyclic anhydrides). The cooperative catalytic mechanism of this system has been elucidated: borane acts as a Lewis acid to activate epoxides, and onium salt acts as a nucleophilic initiator. Existing studies have generally confirmed that the ring-opening of epoxides is the rate-determining step in the epoxide / anhydride copolymerization reaction. In the borane / onium salt binary system, this process is considered to proceed through a trimolecular reaction, resulting in low levels of both borane and chain-growth species concentrations. This dilution effect driven by entropy increase significantly reduces the polymerization activity at low catalyst loadings. Although the binding of borane and onium salt can promote their proximity, the high dissociation degree of onium salt limits this effect.

[0004] Subsequent studies further designed single-molecule bifunctional catalysts, integrating borane and onium salt into the same molecule. Although this strategy has somewhat improved the catalytic activity, the current molecular weight (Mn = 94.5 kDa) and turnover frequency (TOF = 915 h⁻¹) of boron-based catalysts in epoxide / anhydride copolymerization are still significantly lower than those of metal catalysts (Mn = 167 kDa, TOF = 1901 h⁻¹). In addition, the inherent air sensitivity of boron-based catalysts severely restricts their production, storage, and practical applications. Summary of the Invention

[0005] In view of the above problems existing in the prior art, the present invention discloses a single - molecule bifunctional organic catalyst specifically for the ring - opening copolymerization of epoxides and cyclic anhydrides. Its turnover frequency (TOF) can reach up to 13500 h⁻¹ at most, the turnover number (TON) is as high as 6000, and the prepared polymer has the advantages of high molecular weight and low molecular weight distribution. In addition, this catalyst also exhibits excellent air stability and thermal stability.

[0006] The specific technical solution is as follows:

[0007] A single - molecule bifunctional organic catalyst for the ring - opening copolymerization of epoxides and cyclic anhydrides has the structural formula shown in the following formula (Ⅰ):

[0008] (Ⅰ);

[0009] In formula (Ⅰ), X is selected from an alkyl boron group, and the structural formula is shown in the following formula (Ⅱ - 1) or (II - 2):

[0010] (Ⅱ - 1); (II - 2);

[0011] In the formula: B is a boron atom; R 1 is selected from an alkyl group; represents a connecting bond;

[0012] The structural formula of Y is shown in the following formula (Ⅲ):

[0013] (Ⅲ);

[0014] In the formula: O is an oxygen atom; R 2 is selected from one or more of Li, Na, K, Cs, quaternary ammonium cations, and bis(triphenylphosphine) ammonium cations; represents a connecting bond;

[0015] L is selected from unsubstituted C 4 ~C 11 alkyl.

[0016] Based on the long - term research on organic catalytic polymerization, the present invention discloses a single - molecule bifunctional organic catalyst with a novel structure. By using the covalent borane - oxyanion strategy, an alkyl boron and an alkoxide are combined in a single - molecule catalyst / initiator, thereby realizing the effective intramolecular activation of the initiator / chain end. The catalyst can achieve high catalytic efficiency and high controllability, and can also protect the boron center from air oxidation through the tight coordination of the oxyanion, thus ensuring that the catalyst has excellent air stability and thermal stability.

[0017] Preferably:

[0018] R 1Selected from , or .

[0019] Preferably:

[0020] The structural formula of the single-molecule bifunctional organic catalyst is selected from one or more of the following formulas (I-1) to (I-14):

[0021] (I-1);

[0022] (I-2);

[0023] (I-3);

[0024] (I-4);

[0025] (I-5);

[0026] (I-6);

[0027] (I-7);

[0028] (I-8);

[0029] (I-9);

[0030] (I-10);

[0031] (I-11);

[0032] (I-12);

[0033] (I-13);

[0034] (I-14).

[0035] More preferably, the structural formula of the single-molecule bifunctional organic catalyst is selected from one or more of the above formulas (I-3) to (I-6), (I-12) to (I-14);

[0036] Even more preferably, the structural formula of the single-molecule bifunctional organic catalyst is selected from one or more of the above formulas (I-4) to (I-6), (I-12) to (I-14);

[0037] Most preferably, the structural formula of the single-molecule bifunctional organic catalyst is selected from the above formula (I-12).

[0038] With the continuous optimization of the above catalyst structural formula, the catalytic activity and controllability of each catalyst in the ring-opening copolymerization reaction of epoxides and cyclic anhydrides are continuously improved.

[0039] The present invention also discloses a preparation method of the single-molecule bifunctional organic catalyst for the ring-opening copolymerization of the above epoxides and cyclic anhydrides:

[0040] When R 2 is selected from at least one of Li, Na, K, and Cs, the steps include:

[0041] Mix raw material 1 with the following formula W 1 structure, alkali metal and solvent A evenly to obtain raw material liquid I, and then mix raw material 2 with the following formula W 2 structure with raw material liquid I for an addition reaction to obtain the single-molecule bifunctional organic catalyst;

[0042] W 1 ; Or W 2 ;

[0043] When R 2 is selected from quaternary ammonium cations and / or bis(triphenylphosphine)ammonium cations, the steps include:

[0044] Mix raw material 1 with the above formula W 1 structure, alkali metal and solvent A evenly to obtain raw material liquid I, and then mix raw material 2 with the above formula W 2 structure with raw material liquid I for an addition reaction to obtain an intermediate product;

[0045] Mix the intermediate product with solvent B to obtain raw material liquid II, mix raw material 3 with solvent B to obtain raw material liquid III, and mix raw material liquid II with raw material liquid III and then carry out an ion exchange reaction to obtain the single-molecule bifunctional organic catalyst;

[0046] The raw material 3 is selected from one or more of bis(triphenylphosphine)ammonium chloride, tetrabutylammonium chloride, and 1,3-bis(2,4,6-trimethylphenyl)imidazolium chloride.

[0047] Preferably:

[0048] The solvent A is selected from one or more of tetrahydrofuran, n-hexane, diethyl ether, and methyl tert-butyl ether;

[0049] More preferably, the solvent A is selected from tetrahydrofuran.

[0050] Preferably:

[0051] The alkali metal is selected from one or more of Li, Na, K, and Cs;

[0052] More preferably, the alkali metal is selected from Na and K; even more preferably, it is K.

[0053] Preferably:

[0054] The raw material 1 is selected from one or more of 3-buten-1-ol, 4-penten-1-ol, 5-hexen-1-ol, 8-nonen-1-ol, 9-decen-1-ol, and 10-undecen-1-ol.

[0055] Preferably:

[0056] The molar ratio of raw material 1 to the alkali metal is 1:(1.0 - 1.5);

[0057] More preferably, raw material 1 and the alkali metal are added in equimolar amounts.

[0058] Preferably:

[0059] The molar ratio of raw material 1 to raw material 2 is 1:(1.0 - 1.5);

[0060] More preferably, the molar ratio of raw material 1 to raw material 2 is 1:1.25.

[0061] Preferably:

[0062] In the raw material liquid I, the concentration of raw material 1 is 0.8 - 1.2 mol / L;

[0063] More preferably, the concentration of raw material 1 is 1 mol / L;

[0064] Preferably:

[0065] The temperature of the addition reaction is 80 - 100 °C.

[0066] Preferably:

[0067] The solvent B is selected from one or more of acetonitrile, acetone, chloroform, and dichloromethane;

[0068] More preferably, it is acetonitrile.

[0069] Preferably:

[0070] The concentration of the raw material liquid II is 0.8 - 1.2 mol / L;

[0071] More preferably, the concentration of the raw material liquid II is 1 mol / L;

[0072] Preferably:

[0073] The concentration of the raw material solution III is 0.8 - 1.2 mol / L;

[0074] Further preferably, the concentration of the raw material solution III is 1 mol / L;

[0075] Preferably:

[0076] The volume ratio of the raw material solution II to the raw material solution III is 1:(1.0 - 1.3);

[0077] Further preferably, the raw material solution II and the raw material solution III are added in equal volume.

[0078] The present invention also discloses a ring-opening copolymerization reaction of an epoxide and a cyclic anhydride, using the above-mentioned single-molecule bifunctional organic catalyst.

[0079] Specifically:

[0080] Mix the epoxide monomer, the cyclic anhydride monomer and the single-molecule bifunctional organic catalyst, and carry out the polymerization reaction under the autogenous pressure.

[0081] It has been found through experiments that the single-molecule bifunctional organic catalyst disclosed in the present invention has the advantages of high catalytic efficiency and controllable reaction, which is reflected in that the catalytic efficiency can be regulated by adjusting the catalyst concentration, the reactant concentration, the reaction time and the reaction temperature, etc.

[0082] Preferably:

[0083] The molar ratio of the epoxide monomer to the cyclic anhydride monomer is (2 - 8):1;

[0084] Further preferably:

[0085] The molar ratio of the epoxide monomer to the cyclic anhydride monomer is (3.6 - 7):1;

[0086] More preferably (3.6 - 5):1.

[0087] Preferably:

[0088] The molar ratio of the cyclic anhydride monomer to the single-molecule bifunctional organic catalyst is (100 - 100000):1;

[0089] Further preferably:

[0090] The molar ratio of the cyclic anhydride monomer to the single-molecule bifunctional organic catalyst is (1000 - 100000):1.

[0091] The single-molecule bifunctional organic catalyst disclosed in the present invention also has universality and is applicable to a variety of monomers.

[0092] Preferably:

[0093] The epoxide monomer is selected from one or more of ethylene oxide, propylene oxide, butylene oxide, cyclohexene oxide, phenyl glycidyl ether, benzyl glycidyl ether, isobutene oxide, epichlorohydrin, styrene oxide;

[0094] The cyclic anhydride monomer is selected from one or more of phthalic anhydride, maleic anhydride, succinic anhydride, glutaric anhydride, adipic anhydride, biphenyl anhydride, 3,3-tetramethylenepentanedioic anhydride, 1,1-cyclohexanediacetic anhydride, diglycolic anhydride, norbornenedicarboxylic anhydride, tetrachlorophthalic anhydride, tetrabromophthalic anhydride.

[0095] When the polymerization reaction is solution polymerization, a solvent commonly used in the solution polymerization reaction in the art can also be added.

[0096] Preferably, the temperature of the polymerization reaction is 100-180 °C.

[0097] Compared with the prior art, the present invention has the following beneficial effects:

[0098] (1) The present invention discloses a single-molecule bifunctional organic catalyst with a novel structure, which can catalyze the ring-opening copolymerization of epoxides and cyclic anhydrides, and the catalyst exhibits ultra-high activity and good reaction controllability in the ring-opening copolymerization; the ultra-high activity of the organic catalyst can be comparable to that of metal complexes, with a turnover number (TON) as high as 6000 and a turnover frequency (TOF) as high as 13500 h⁻¹; and the reaction has high controllability, and a copolymer product with a customized structure, predictable molecular weight, and narrow molecular weight distribution can be prepared; the synthesis process of the catalyst is simple and scalable, and a wide range of regulation of the ring-opening copolymerization activity can be achieved.

[0099] (2) The single-molecule bifunctional organic catalyst disclosed in the present invention exhibits excellent air stability and thermal stability during the process of catalyzing the ring-opening copolymerization of epoxides and cyclic anhydrides, and still maintains ultra-high catalytic activity at a high temperature of 180 °C; after being placed in air with a normal temperature and an air humidity of 45-60% for 5 days, its catalytic activity is basically equivalent to that of the fresh catalyst. BRIEF DESCRIPTION OF THE DRAWINGS

[0100] Figure 1 1H NMR spectrum of the catalyst prepared in Example 1 1 1H NMR spectrum;

[0101] Figure 2 13C NMR spectrum of the catalyst prepared in Example 1 13 13C NMR spectrum;

[0102] Figure 3 11B NMR spectrum of the catalyst prepared in Example 1 11 11B NMR spectrum;

[0103] Figure 4Schematic diagram of the principle for preparing the catalyst in Example 11;

[0104] Figure 5 for preparing the catalyst in Example 11 1 1H NMR spectrum;

[0105] Figure 6 for preparing the catalyst in Example 11 13 13C NMR spectrum;

[0106] Figure 7 for preparing the catalyst in Example 11 11 11B NMR spectrum;

[0107] Figure 8 for preparing the catalyst in Example 11 35 31P NMR spectrum;

[0108] Figure 9 for the copolymer product prepared in Application Example 1 1 1H NMR spectrum;

[0109] Figure 10 for the copolymer product prepared in Application Example 1 13 13C NMR spectrum. Detailed implementation manners

[0110] To make the objectives, technical solutions and effects of the present invention clearer and more definite, the present invention will be further described in detail below with reference to the embodiments and the accompanying drawings. It should be understood, however, that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0111] In the ranges disclosed in the present invention, the endpoints and any values are not limited to the precise ranges or values. These ranges or values should be understood to include values close to these ranges or values. For numerical ranges, between the endpoint values of each range, between the endpoint values of each range and individual point values, and between individual point values, they can be combined with each other to obtain one or more new numerical ranges, and these numerical ranges should be regarded as specifically disclosed in the present invention.

[0112] The terms used herein are only for describing specific embodiments and are not intended to limit the present disclosure. The terms "including", "comprising" and the like used herein indicate the presence of the described features, steps, operations and / or components, but do not exclude the presence or addition of one or more other features, steps, operations or components.

[0113] All terms used herein (including technical and scientific terms) have the meanings commonly understood by those skilled in the art, unless otherwise defined. It should be noted that the terms used herein should be interpreted as having a meaning consistent with the context of this specification and should not be interpreted in an idealized or overly rigid manner.

[0114] It should be noted that, unless otherwise defined, the technical terms or scientific terms used in the present invention should have the ordinary meanings understood by those with ordinary skills in the field to which the present invention belongs. If descriptions such as "first", "second", etc. are involved throughout the text, these "first", "second", etc. descriptions are only used to distinguish similar objects, and should not be understood as indicating or implying their relative importance, sequence, or implicitly indicating the quantity of the technical features indicated. It should be understood that the data described by "first", "second", etc. can be interchanged under appropriate circumstances.

[0115] Example 1

[0116] Add an anhydrous tetrahydrofuran solution (2 mL) of 3-buten-1-ol (0.144 g, 0.002 mol) to a Schlenk flask equipped with a magnetic stir bar. Place the flask under an N 2 atmosphere, add potassium metal (0.080 g, 0.002 mol), and react at 25 °C overnight to obtain Feedstock Solution I; then add a THF solution (5 mL, 0.5 M, 0.0025 mol) of 9-borabicyclo[3.3.1]nonane (9-BBN). React the resulting reaction mixture at 80 °C overnight, then cool to room temperature and concentrate under vacuum to obtain a crude product, which is further purified by washing with anhydrous n-hexane three times. Then dry the product under vacuum at 60 °C to constant weight to obtain 0.378 g of a white solid product (yield: 81%), denoted as Catalyst 1.

[0117] The structural formula of the catalyst prepared in this example is shown as follows:

[0118] ;

[0119] The 1 1H NMR spectrum, 13 13C NMR spectrum, and 11 11B NMR spectrum of the catalyst prepared in this example are shown in Figure 1 、 2 、and 3 respectively.

[0120] Example 2

[0121] Add an anhydrous tetrahydrofuran solution (10 mL) of 4-penten-1-ol (0.861 g, 0.01 mol) to a Schlenk flask equipped with a magnetic stir bar. Place the flask under an N 2Under an atmosphere, 0.400 g (0.01 mol) of metallic potassium was added and the mixture was placed at 25 °C and reacted overnight to obtain Feedstock Solution I; then a THF solution of 9-BBN (25 mL, 0.5 M, 0.0125 mol) was added, and the resulting reaction mixture was reacted at 80 °C overnight, then cooled to room temperature and concentrated in vacuo to obtain a crude product, which was further purified by washing with anhydrous n-hexane three times. Then the product was dried in vacuo at 60 °C to constant weight to obtain 2.010 g of a white solid product (yield 82%), denoted as Catalyst 2.

[0122] The structural formula of the catalyst prepared in this example is shown as follows:

[0123] 。

[0124] Example 3

[0125] An anhydrous THF solution (2 mL) of 5-hexen-1-ol (0.201 g, 0.002 mol) was added to a Schlenk flask equipped with a magnetic stirrer. The flask was placed under an N 2 atmosphere, 0.080 g (0.002 mol) of metallic potassium was added and the mixture was placed at 25 °C and reacted overnight to obtain Feedstock Solution I; then a THF solution of 9-BBN (5 mL, 0.5 M, 0.0025 mol) was added, and the resulting reaction mixture was reacted at 80 °C overnight, then cooled to room temperature and concentrated in vacuo to obtain a crude product, which was further purified by washing with anhydrous n-hexane three times. Then the product was dried in vacuo at 60 °C to constant weight to obtain 0.372 g of a white solid product (yield 72%), denoted as Catalyst 3.

[0126] The structural formula of the catalyst prepared in this example is shown as follows:

[0127] 。

[0128] Example 4

[0129] An anhydrous THF solution (2 mL) of 8-nonen-1-ol (0.284 g, 0.002 mol) was added to a Schlenk flask equipped with a magnetic stirrer. The flask was placed under an N 2 atmosphere, 0.080 g (0.002 mol) of metallic potassium was added and the mixture was placed at 25 °C and reacted overnight to obtain Feedstock Solution I; then a THF solution of 9-BBN (5 mL, 0.5 M, 0.0025 mol) was added, and the resulting reaction mixture was reacted at 80 °C overnight, then cooled to room temperature and concentrated in vacuo to obtain a crude product, which was further purified by washing with anhydrous n-hexane three times. Then the product was dried in vacuo at 60 °C to constant weight to obtain 0.429 g of a white solid product (yield 71%), denoted as Catalyst 4.

[0130] The structural formula of the catalyst prepared in this example is shown as follows:

[0131] .

[0132] Example 5

[0133] Add an anhydrous tetrahydrofuran solution (2 mL) of 9-decen-1-ol (0.312 g, 0.002 mol) to a Schlenk flask equipped with a magnetic stir bar. Place the flask under an N 2 atmosphere, add potassium metal (0.080 g, 0.002 mol), and react at 25 °C overnight to obtain Feedstock Solution I; then add a THF solution of 9-BBN (5 mL, 0.5 M, 0.0025 mol), react the resulting reaction mixture at 80 °C overnight, then cool to room temperature, concentrate in vacuo to obtain a crude product, and further purify by washing three times with anhydrous n-hexane. Then dry the product in vacuo at 60 °C to constant weight to obtain 0.411 g of a white solid product (yield 65%), denoted as Catalyst 5.

[0134] The structural formula of the catalyst prepared in this example is shown as follows:

[0135] .

[0136] Example 6

[0137] Add an anhydrous tetrahydrofuran solution (2 mL) of 10-undecen-1-ol (0.341 g, 0.002 mol) to a Schlenk flask equipped with a magnetic stir bar. Place the flask under an N 2 atmosphere, add potassium metal (0.080 g, 0.002 mol), and react at 25 °C overnight to obtain Feedstock Solution I; then add a THF solution of 9-BBN (5 mL, 0.5 M, 0.0025 mol), react the resulting reaction mixture at 80 °C overnight, then cool to room temperature, concentrate in vacuo to obtain a crude product, and further purify by washing three times with anhydrous n-hexane. Then dry the product in vacuo at 60 °C to constant weight to obtain 0.443 g of a white solid product (yield 67%), denoted as Catalyst 6.

[0138] The structural formula of the catalyst prepared in this example is shown as follows:

[0139] .

[0140] Example 7

[0141] Add an anhydrous tetrahydrofuran solution (5 mL) of cis-cyclooctene (1.102 g, 0.01 mol) to a Schlenk flask equipped with a magnetic stir bar. Place the flask under an N 2 atmosphere, cool it to -20 °C, and slowly add a THF solution (5 mL, 1 M, 0.005 mol) of borane tetrahydrofuran complex to the flask. Then raise the temperature to 100 °C and react overnight, and then cool to room temperature to prepare a THF solution of dicyclooctylborane.

[0142] Add an anhydrous tetrahydrofuran solution (2 mL) of 4-penten-1-ol (0.144 g, 0.002 mol) to a Schlenk flask equipped with a magnetic stir bar. Place the flask under an N 2 atmosphere, add potassium metal (0.080 g, 0.002 mol), and react at 25 °C overnight to obtain Feedstock Solution I; then add a THF solution (5 mL, 0.5 M, 0.0025 mol) of dicyclooctylborane, react the resulting reaction mixture at 80 °C overnight, then cool to room temperature, concentrate under vacuum to obtain a crude product, and further purify it by washing three times with anhydrous n-hexane. Then dry the product under vacuum at 60 °C to constant weight to obtain 0.436 g of a white solid product (yield 61%), denoted as Catalyst 7.

[0143] The structural formula of the catalyst prepared in this example is shown as follows:

[0144] .

[0145] Example 8

[0146] Add an anhydrous tetrahydrofuran solution (5 mL) of cyclohexene (0.821 g, 0.01 mol) to a Schlenk flask equipped with a magnetic stir bar. Place the flask under an N 2 atmosphere, cool it to -20 °C, and slowly add a THF solution (5 mL, 1 M, 0.005 mol) of borane tetrahydrofuran complex to the flask. Then raise the temperature to 100 °C and react overnight, and then cool to room temperature to prepare a THF solution of dicyclohexylborane.

[0147] Add an anhydrous tetrahydrofuran solution (2 mL) of 4-penten-1-ol (0.144 g, 0.002 mol) to a Schlenk flask equipped with a magnetic stir bar. Place the flask under an N 2Under an atmosphere, 0.080 g (0.002 mol) of metallic potassium was added and the mixture was reacted overnight at 25 °C to obtain stock solution I; then a THF solution (5 mL, 0.5 M, 0.0025 mol) of dicyclohexylborane was added, and the resulting reaction mixture was reacted overnight at 80 °C, then cooled to room temperature and concentrated in vacuo to obtain a crude product, which was further purified by washing three times with anhydrous n-hexane. Then the product was dried in vacuo at 60 °C to constant weight to obtain 0.387 g of a white solid product (yield 64%), denoted as catalyst 8.

[0148] The structural formula of the catalyst prepared in this example is shown as follows:

[0149] 。

[0150] Example 9

[0151] To a Schlenk flask equipped with a magnetic stirrer was added an anhydrous THF solution (2 mL) of 4-penten-1-ol (0.144 g, 0.002 mol). The flask was placed under an N 2 atmosphere, 0.080 g (0.002 mol) of metallic potassium was added and the mixture was reacted overnight at 25 °C to obtain stock solution I; then a THF solution (5 mL, 0.5 M, 0.0025 mol) of (-)-diisopinocampheylborane was added, and the resulting reaction mixture was reacted overnight at 80 °C, then cooled to room temperature and concentrated in vacuo to obtain a crude product, which was further purified by washing three times with anhydrous n-hexane. Then the product was dried in vacuo at 60 °C to constant weight to obtain 0.533 g of a white solid product (yield 81%), denoted as catalyst 9.

[0152] The structural formula of the catalyst prepared in this example is shown as follows:

[0153] 。

[0154] Example 10

[0155] To a Schlenk flask equipped with a magnetic stirrer was added an anhydrous THF solution (2 mL) of 8-nonen-1-ol (0.284 g, 0.002 mol). The flask was placed under an N 2Under an inert atmosphere, sodium metal (0.050 g, 0.0022 mol) was added and the mixture was reacted overnight at 25 °C to obtain Feedstock Solution I. Then, a THF solution of 9-BBN (5 mL, 0.5 M, 0.0025 mol) was added, and the resulting reaction mixture was reacted overnight at 80 °C, then cooled to room temperature and concentrated in vacuo to obtain a crude product, which was further purified by washing three times with anhydrous n-hexane. Then the product was dried in vacuo at 60 °C to constant weight to obtain 0.360 g of a white solid product (yield 63%), denoted as Catalyst 10.

[0156] The structural formula of the catalyst prepared in this example is shown as follows:

[0157] 。

[0158] Example 11

[0159] An anhydrous acetonitrile solution (2 mL) of Catalyst 2 (0.492 g, 0.002 mmol) prepared in Example 2 was added to a Schlenk flask equipped with a magnetic stir bar. Another Schlenk flask was charged with an anhydrous acetonitrile solution (2 mL) of bis(triphenylphosphine)ammonium chloride (1.205 g, 0.0021 mmol). The two were mixed together to form a suspension, which was then filtered to obtain a bright yellow clear and transparent solution. The solution was concentrated in vacuo to obtain a yellow solid crude product, which was then dissolved in anhydrous tetrahydrofuran and filtered to obtain a bright yellow clear and transparent solution. The solution was concentrated in vacuo, washed three times with anhydrous n-hexane, and the product was dried in vacuo at 60 °C to constant weight to obtain 1.386 g of a yellow solid product (yield 93%), denoted as Catalyst 11.

[0160] The structural formula of the catalyst prepared in this example is shown as follows:

[0161] 。

[0162] Figure 4 This is a schematic diagram of the principle of the single-molecule bifunctional organic catalyst prepared in this example. As can be seen from the figure, this is a catalyst / initiator structure with a brand-new structure.

[0163] The 1 1H NMR spectrum, 13 13C NMR spectrum, 11 11B NMR spectrum, and 35 31P NMR spectrum of the catalyst prepared in this example are shown in Figure 5 、 6 、7, 8 respectively.

[0164] Example 12

[0165] An anhydrous acetonitrile solution (2 mL) of catalyst 4 (0.604 g, 0.002 mol) prepared in Example 4 was added to a Schlenk flask equipped with a magnetic stir bar; another Schlenk flask was taken and an anhydrous acetonitrile solution (2 mL) of bis(triphenylphosphine)ammonium chloride (1.205 g, 0.0021 mol) was added. The two solutions were mixed together to form a suspension, and then filtered to obtain a bright yellow clear and transparent solution. The solution was concentrated in vacuo to obtain a crude yellow solid product, which was then dissolved in anhydrous tetrahydrofuran and then filtered to obtain a bright yellow clear and transparent solution. The solution was concentrated in vacuo, washed three times with anhydrous n-hexane, and then the product was dried in vacuo at 60 °C to constant weight to obtain 1.362 g of a yellow solid product (yield 85%), denoted as catalyst 12.

[0166] The structural formula of the catalyst prepared in this example is shown as follows:

[0167] 。

[0168] Example 13

[0169] An anhydrous acetonitrile solution (2 mL) of catalyst 6 (0.660 g, 0.002 mol) prepared in Example 6 was added to a Schlenk flask equipped with a magnetic stir bar; another Schlenk flask was taken and an anhydrous acetonitrile solution (2 mL) of bis(triphenylphosphine)ammonium chloride (1.205 g, 0.0021 mol) was added. The two solutions were mixed together to form a suspension, and then filtered to obtain a bright yellow clear and transparent solution. The solution was concentrated in vacuo to obtain a crude yellow solid product, which was then dissolved in anhydrous tetrahydrofuran and then filtered to obtain a bright yellow clear and transparent solution. The solution was concentrated in vacuo, washed three times with anhydrous n-hexane, and then the product was dried in vacuo at 60 °C to constant weight to obtain 1.344 g of a yellow solid product (yield 81%), denoted as catalyst 13.

[0170] The structural formula of the catalyst prepared in this example is shown as follows:

[0171] 。

[0172] Comparative Example 1 Binary system TEB / PPNCl

[0173] In the article "Fully alternating and regioselective ring-opening copolymerization of phthalic anhydride with epoxides using highly active metal-free Lewis pairs as a catalyst", Debashis Chakrabort et al. used a binary catalytic system TEB / PPNCl, and the structural formula is shown as follows:

[0174] 。

[0175] Comparative Example 2 Binary system BBN-R 4 NCl

[0176] In the article "Record Productivity and Unprecedented Molecular Weight for Ring-Opening Copolymerization of Epoxides and Cyclic Anhydrides Enabled by Organoboron Catalysts", Wu et al. used a single-molecule bifunctional catalytic system BBN-R 4 NCl, and the structural formula is shown as follows:

[0177] 。

[0178] Application Example 1: Using Catalyst 2 to catalyze the ring-opening copolymerization of ethylene oxide and phthalic anhydride to produce poly(ethylene oxide-alt-phthalic anhydride) (poly(EO-alt-PA))

[0179] In N 2 In a glove box under an atmosphere, a 10 mL pressure-resistant tube with a magnetic stir bar was dried overnight in an oven at 110 °C and then immediately placed in the glove box. After maintaining under vacuum for 2 - 3 hours, the pressure-resistant tube was transferred into a glove box under an N 2 atmosphere. In a 10 mL pressure-resistant tube equipped with a magnetic stir bar, Catalyst 2 (3.3 mg, 0.014 mmol) and phthalic anhydride (PA, 211 mg, 1.429 mmol) were added. The pressure-resistant tube was placed in a refrigerator at -20 °C, sealed and allowed to stand for 5 min, and then ethylene oxide (EO, 0.5 mL, 10.003 mmol) was quickly added to the pressure-resistant tube through a syringe. The pressure-resistant tube was heated to 180 °C and reacted for 5 min. Then, a part of the sample was taken from the crude product and quenched with benzoic acid to pass through 1The composition of the crude product and the conversion rate of raw materials were determined by \(^1H\) NMR spectroscopy. The crude product was dissolved in CH 2 Cl 2 , and the polymer was precipitated from cooled ethanol. The product was collected by centrifugation and finally the obtained polymer was dried to a constant weight in a vacuum drying oven at 40 °C. The molecular weight and molecular weight distribution of the polymer were determined by gel permeation chromatography, and the test results are shown in Table 1.

[0180] Figure 9 , 10 are the \(^1H\) NMR spectrum and 1 the \(^{13}C\) NMR spectrum of the copolymer product prepared in Application Example 1, respectively. 13 C NMR spectrum.

[0181] Application Examples 2 - 13: Using catalysts 1, 3 - 13 to catalyze the ring-opening copolymerization of ethylene oxide and phthalic anhydride to produce poly(EO-alt-PA)

[0182] The preparation process was basically the same as that of Application Example 1, except that the catalyst for the polymerization reaction was successively replaced with equimolar amounts of catalysts 1 and 3 - 13, and the reaction time for Application Examples 11 - 13 was adjusted to 2 min. The molecular weight and molecular weight distribution of the polymers prepared in each application example were determined by gel permeation chromatography, and the test results are shown in Table 1.

[0183] Application Example 14: Using catalyst 11 to catalyze the ring-opening copolymerization of ethylene oxide and phthalic anhydride to produce poly(EO-alt-PA)

[0184] In a glove box under N 2 atmosphere, a 10 mL pressure-resistant tube with a magnetic stirrer was dried overnight in an oven at 110 °C and then immediately placed in the glove box. After maintaining under vacuum for 2 - 3 hours, the pressure-resistant tube was transferred into a glove box under N 2 atmosphere. In a 10 mL pressure-resistant tube equipped with a magnetic stirrer, catalyst 11 (0.4 mg, 0.00056 mmol) and phthalic anhydride (PA, 414 mg, 2.801 mmol) were added. The pressure-resistant tube was placed in a refrigerator at -20 °C, sealed and allowed to stand for 5 min, and then ethylene oxide (EO, 0.7 mL, 14.004 mmol) was quickly added to the pressure-resistant tube through a syringe. The pressure-resistant tube was heated to 180 °C and reacted for 14 min. Then, a part of the sample was taken from the crude product and quenched with benzoic acid to determine the composition of the crude product and the conversion rate of raw materials by 1 \(^1H\) NMR spectroscopy. The crude product was dissolved in CH 2 Cl 2 , and the polymer was precipitated from cooled ethanol. The product was collected by centrifugation and finally the obtained polymer was dried to a constant weight in a vacuum drying oven at 40 °C. The molecular weight and molecular weight distribution of the polymer were determined by gel permeation chromatography, and the test results are shown in Table 1.

[0185] Application Example 15

[0186] The preparation process is basically the same as that of Application Example 14, except that:

[0187] The amount of ethylene oxide used is replaced with 0.5 mL (10.083 mmol), and the molar ratio of ethylene oxide, phthalic anhydride to catalyst 11 is 18000:5000:1;

[0188] The reaction time is replaced with 30 min.

[0189] The molecular weight and molecular weight distribution of the prepared polymer are measured by gel chromatography, and the test results are shown in Table 1.

[0190] Application Example 16

[0191] The preparation process is basically the same as that of Application Example 14, except that:

[0192] The amount of catalyst 11 used is replaced with 0.2 mg (0.0003 mmol), and the molar ratio of ethylene oxide, phthalic anhydride to catalyst 11 is 50000:10000:1;

[0193] The reaction time is replaced with 25 min.

[0194] The molecular weight and molecular weight distribution of the prepared polymer are measured by gel chromatography, and the test results are shown in Table 1.

[0195] Application Example 17

[0196] The preparation process is basically the same as that of Application Example 14, except that:

[0197] The amount of catalyst 11 used is replaced with 0.02 mg (0.00003 mmol), and the molar ratio of ethylene oxide, phthalic anhydride to catalyst 11 is 500000:100000:1;

[0198] The reaction time is replaced with 27 min.

[0199] The molecular weight and molecular weight distribution of the prepared polymer are measured by gel chromatography, and the test results are shown in Table 1.

[0200] Application Example 18: Using the TEB / PPNCl binary catalytic system to catalyze the ring-opening copolymerization of ethylene oxide and phthalic anhydride to generate poly(EO-alt-PA)

[0201] The preparation process is basically the same as that of Application Example 16, except that the catalyst for the polymerization reaction is replaced with TEB / PPNCl provided in Comparative Example 1. The molecular weight and molecular weight distribution of the prepared polymer are measured by gel chromatography, and the test results are shown in Table 1.

[0202] Application Example 19: Using BBN-R 4 The NCl binary catalytic system catalyzes the ring-opening copolymerization of ethylene oxide and phthalic anhydride to produce poly(EO-alt-PA), as a comparative example.

[0203] The preparation process is basically the same as that of Application Example 16, except that the catalyst for the polymerization reaction is replaced with BBN-R provided in Comparative Example 2 4 NCl. The molecular weight and molecular weight distribution of the prepared polymer were measured by gel chromatography, and the test results are shown in Table 1.

[0204] Application Example 20: Using Catalyst 11 exposed to air to catalyze the ring-opening copolymerization of ethylene oxide and phthalic anhydride to produce poly(EO-alt-PA)

[0205] The preparation process is basically the same as that of Application Example 14, except that Catalyst 11 is placed in air at room temperature and air humidity of 45 - 60% for 5 days before use. The molecular weight and molecular weight distribution of the prepared polymer were measured by gel chromatography, and the test results are shown in Table 1.

[0206] Application Example 21: Using Catalyst 11 to catalyze the ring-opening copolymerization of propylene oxide and phthalic anhydride to produce poly(PO-alt-PA)

[0207] In the glove box under N 2 atmosphere, a 10 mL pressure-resistant tube with a magnetic stirrer was dried overnight in an oven at 110 °C, and then immediately placed in the glove box. After maintaining under vacuum for 2 - 3 hours, the pressure-resistant tube was transferred into the glove box under N 2 atmosphere. In a 10 mL pressure-resistant tube equipped with a magnetic stirrer, Catalyst 11 (0.4 mg, 0.57 µmol) and phthalic anhydride (PA, 423 mg, 2.858 mmol) were added. Propylene oxide (PO, 0.6 mL, 8.574 mmol) was taken and added to the pressure-resistant tube through a syringe. The pressure-resistant tube was heated to 180 °C and reacted for 30 min. Then, a part of the sample was taken from the crude product and quenched with benzoic acid to determine the composition of the crude product and the raw material conversion rate by 1 H NMR spectroscopy. The crude product was dissolved in CH 2 Cl 2 and the polymer was precipitated from cooled ethanol. The product was collected by centrifugation, and finally the obtained polymer was dried to a constant weight in a vacuum drying oven at 40 °C. The molecular weight and molecular weight distribution of the polymer were measured by gel chromatography, and the test results are shown in Table 2.

[0208] Application Example 22: Using Catalyst 11 to catalyze the ring-opening copolymerization of cyclohexene oxide and phthalic anhydride to produce poly(CHO-alt-PA)

[0209] In N2 In a glove box under an [atmosphere], a 10 mL pressure-resistant tube with a magnetic stirrer was dried overnight in an oven at 110 °C and then immediately placed in the glove box. After maintaining under vacuum for 2 - 3 hours, the pressure-resistant tube was transferred into an N 2 -atmosphere glove box. In a 10 mL pressure-resistant tube equipped with a magnetic stirrer, catalyst 11 (0.4 mg, 0.57 μmol) and phthalic anhydride (PA, 423 mg, 2.858 mmol) were added. Cyclohexene oxide (CHO, 0.6 mL, 5.716 mmol) was taken and added to the pressure-resistant tube through a syringe. The pressure-resistant tube was heated to 180 °C and reacted for 30 min. Then, a part of the sample was taken from the crude product and quenched with benzoic acid to determine the composition of the crude product and the conversion of raw materials by 1 H NMR spectroscopy. The crude product was dissolved in CH 2 Cl 2 and the polymer was precipitated from cooled ethanol. The product was collected by centrifugation and finally the obtained polymer was dried to a constant weight in a vacuum drying oven at 40 °C. The molecular weight and molecular weight distribution of the polymer were determined by gel permeation chromatography, and the test results are shown in Table 2.

[0210] Application Example 23: Catalyzing the ring-opening copolymerization of butylene oxide and phthalic anhydride to produce poly(BO-alt-PA) using catalyst 11

[0211] In a glove box under an N 2 -atmosphere, a 10 mL pressure-resistant tube with a magnetic stirrer was dried overnight in an oven at 110 °C and then immediately placed in the glove box. After maintaining under vacuum for 2 - 3 hours, the pressure-resistant tube was transferred into an N 2 -atmosphere glove box. In a 10 mL pressure-resistant tube equipped with a magnetic stirrer, catalyst 11 (0.4 mg, 0.57 μmol) and phthalic anhydride (PA, 423 mg, 2.858 mmol) were added. Butylene oxide (BO, 0.6 mL, 7.145 mmol) was taken and added to the pressure-resistant tube through a syringe. The pressure-resistant tube was heated to 180 °C and reacted for 30 min. Then, a part of the sample was taken from the crude product and quenched with benzoic acid to determine the composition of the crude product and the conversion of raw materials by 1 H NMR spectroscopy. The crude product was dissolved in CH 2 Cl 2 and the polymer was precipitated from cooled ethanol. The product was collected by centrifugation and finally the obtained polymer was dried to a constant weight in a vacuum drying oven at 40 °C. The molecular weight and molecular weight distribution of the polymer were determined by gel permeation chromatography, and the test results are shown in Table 2.

[0212] Application Example 24: Catalyzing the ring-opening copolymerization of phenyl glycidyl ether and phthalic anhydride to produce poly(PGE-alt-PA) using catalyst 11

[0213] In an N 2 atmosphere glove box, a 10 mL pressure-resistant tube with a magnetic stirrer was dried overnight in an oven at 110 °C and then immediately placed in the glove box. After maintaining under vacuum for 2 - 3 hours, the pressure-resistant tube was transferred into an N 2 atmosphere glove box. In a 10 mL pressure-resistant tube equipped with a magnetic stirrer, catalyst 11 (0.4 mg, 0.57 µmol) and phthalic anhydride (PA, 423 mg, 2.858 mmol) were added. Phenyl glycidyl ether (PGE, 0.6 mL, 4.287 mmol) was added to the pressure-resistant tube through a syringe. The pressure-resistant tube was heated to 180 °C and reacted for 30 min. Then, a part of the sample was taken from the crude product and quenched with benzoic acid to determine the composition of the crude product and the raw material conversion rate by 1 H NMR spectroscopy. The crude product was dissolved in CH 2 Cl 2 and the polymer was precipitated from cooled ethanol. The product was collected by centrifugation and finally the obtained polymer was dried to a constant weight in a vacuum drying oven at 40 °C. The molecular weight and molecular weight distribution of the polymer were determined by gel permeation chromatography, and the test results are shown in Table 2.

[0214] Application Example 25: Catalytic ring-opening copolymerization of ethylene oxide and glutaric anhydride using catalyst 11 to produce poly(EO-alt-GA)

[0215] In an N 2 atmosphere glove box, a 10 mL pressure-resistant tube with a magnetic stirrer was dried overnight in an oven at 110 °C and then immediately placed in the glove box. After maintaining under vacuum for 2 - 3 hours, the pressure-resistant tube was transferred into an N 2 atmosphere glove box. In a 10 mL pressure-resistant tube equipped with a magnetic stirrer, catalyst 11 (4.3 mg, 5.716 µmol) and glutaric anhydride (GA, 652 mg, 5.716 mmol) were added. The pressure-resistant tube was placed in a refrigerator at -20 °C, sealed and allowed to stand for 5 min, and then ethylene oxide (EO, 0.7 mL, 14.29 mmol) was quickly added to the pressure-resistant tube through a syringe. The pressure-resistant tube was heated to 100 °C and reacted for 360 min. Then, a part of the sample was taken from the crude product and quenched with benzoic acid to determine the composition of the crude product and the raw material conversion rate by 1 H NMR spectroscopy. The crude product was dissolved in CH 2 Cl 2 and the polymer was precipitated from cooled ethanol. The product was collected by centrifugation and finally the obtained polymer was dried to a constant weight in a vacuum drying oven at 40 °C. The molecular weight and molecular weight distribution of the polymer were determined by gel permeation chromatography, and the test results are shown in Table 2.

[0216] Application Example 26: Catalyzed by catalyst 11, ethylene oxide and diglycolic anhydride undergo ring-opening copolymerization to produce poly(EO-alt-DGA)

[0217] In a glove box under N 2 atmosphere, a 10 mL pressure-resistant tube with a magnetic stirrer was dried overnight in an oven at 110 °C and then immediately placed in the glove box. After maintaining under vacuum for 2 - 3 hours, the pressure-resistant tube was transferred into the glove box under N 2 atmosphere. In a 10 mL pressure-resistant tube equipped with a magnetic stirrer, catalyst 11 (4.3 mg, 5.716 µmol) and diglycolic anhydride (DGA, 663 mg, 5.716 mmol) were added. The pressure-resistant tube was placed in a refrigerator at -20 °C, sealed and allowed to stand for 5 min, and then ethylene oxide (EO, 0.7 mL, 14.29 mmol) was quickly added to the pressure-resistant tube through a syringe. The pressure-resistant tube was heated to 100 °C and reacted for 150 min. Then, a part of the sample was taken from the crude product and quenched with benzoic acid to determine the composition of the crude product and the raw material conversion rate by 1 H NMR spectroscopy. The crude product was dissolved in CH 2 Cl 2 and the polymer was precipitated from cooled ethanol. The product was collected by centrifugation, and finally the obtained polymer was dried to a constant weight in a vacuum drying oven at 40 °C. The molecular weight and molecular weight distribution of the polymer were determined by gel permeation chromatography, and the test results are shown in Table 2.

[0218] Application Example 27: Catalyzed by catalyst 11, ethylene oxide and norbornene dianhydride undergo ring-opening copolymerization to produce poly(EO-alt-NA)

[0219] In a glove box under N 2 atmosphere, a 10 mL pressure-resistant tube with a magnetic stirrer was dried overnight in an oven at 110 °C and then immediately placed in the glove box. After maintaining under vacuum for 2 - 3 hours, the pressure-resistant tube was transferred into the glove box under N 2 atmosphere. In a 10 mL pressure-resistant tube equipped with a magnetic stirrer, catalyst 11 (2.2 mg, 2.858 µmol) and norbornene dianhydride (NA, 469 mg, 2.858 mmol) were added. The pressure-resistant tube was placed in a refrigerator at -20 °C, sealed and allowed to stand for 5 min, and then ethylene oxide (EO, 0.7 mL, 14.29 mmol) was quickly added to the pressure-resistant tube through a syringe. The pressure-resistant tube was heated to 100 °C and reacted for 240 min. Then, a part of the sample was taken from the crude product and quenched with benzoic acid to determine the composition of the crude product and the raw material conversion rate by 1 H NMR spectroscopy. The crude product was dissolved in CH 2 Cl 2Among them, the polymer was precipitated from cooled ethanol. The product was collected by centrifugation, and finally the obtained polymer was dried to a constant weight in a vacuum drying oven at 40 °C. The molecular weight and molecular weight distribution of the polymer were determined by gel chromatography, and the test results are shown in Table 2.

[0220] Application Example 28: Using Catalyst 11 to Catalyze the Ring-Opening Copolymerization of Ethylene Oxide and 3,3-Tetramethylenepentanedioic Anhydride to Produce poly(EO-alt-CPDA)

[0221] In an 2 atmosphere glove box, a 10 mL pressure-resistant tube with a magnetic stir bar was dried overnight in an oven at 110 °C and then immediately placed in the glove box. After maintaining under vacuum for 2 - 3 hours, the pressure-resistant tube was transferred into an 2 atmosphere glove box. In a 10 mL pressure-resistant tube equipped with a magnetic stir bar, Catalyst 11 (2.2 mg, 2.858 µmol) and 3,3-tetramethylenepentanedioic anhydride (CPDA, 481 mg, 2.858 mmol) were added. The pressure-resistant tube was placed in a refrigerator at -20 °C and sealed and allowed to stand for 5 min. Then, ethylene oxide (EO, 0.7 mL, 14.29 mmol) was quickly added to the pressure-resistant tube through a syringe. The pressure-resistant tube was heated to 100 °C and reacted for 180 min. Then, a portion of the sample was taken from the crude product and quenched with benzoic acid to 1 determine the composition of the crude product and the raw material conversion rate by 2 H NMR spectroscopy. The crude product was dissolved in 2 CH

[0222] Application Example 29: Using Catalyst 11 to Catalyze the Ring-Opening Copolymerization of Ethylene Oxide and 1,1-Cyclohexanediacetic Anhydride to Produce poly(EO-alt-CHDA)

[0223] In an 2 atmosphere glove box, a 10 mL pressure-resistant tube with a magnetic stir bar was dried overnight in an oven at 110 °C and then immediately placed in the glove box. After maintaining under vacuum for 2 - 3 hours, the pressure-resistant tube was transferred into an 2In a glove box filled with an inert gas atmosphere. In a 10 mL pressure-resistant tube equipped with a magnetic stir bar, catalyst 11 (2.2 mg, 2.858 μmol) and 1,1-cyclohexanediacetic anhydride (CHDA, 521 mg, 2.858 mmol) were added. The pressure-resistant tube was placed in a refrigerator at -20 °C, sealed and allowed to stand still for 5 min. Then, ethylene oxide (EO, 0.7 mL, 14.29 mmol) was quickly added to the pressure-resistant tube through a syringe. The pressure-resistant tube was heated to 100 °C and reacted for 140 min. Then, a portion of the sample was taken from the crude product and quenched with benzoic acid to determine the composition of the crude product and the monomer conversion rate by 1 H NMR spectroscopy. The crude product was dissolved in CH 2 Cl 2 and the polymer was precipitated from cooled ethanol. The product was collected by centrifugation and finally the obtained polymer was dried to a constant weight in a vacuum drying oven at 40 °C. The molecular weight and molecular weight distribution of the polymer were determined by gel permeation chromatography, and the test results are shown in Table 2.

[0224] Table 1

[0225]

[0226] Note: 1 Conv.(%) : The monomer conversion rate was determined by 1 H NMR measurement. 2 Turnover number (TON) = (moles of monomer consumed) / (moles of catalyst). 3 Turnover frequency (TOF) = (moles of monomer consumed) / (moles of catalyst · hour). 4 M n GPC n: Number-average molecular weight, determined by gel permeation chromatography. 5 Ð: Molecular weight distribution, determined by gel permeation chromatography.

[0227] It can be seen from Table 1 that under the high loading ratios of Application Examples 14 - 16 and the extremely high loading ratio of Application Example 17, the catalysts disclosed in the present invention still maintain high catalytic activity and high controllability; and by adjusting the molar ratios between monomers and between monomers and the catalyst, copolymer products with different molecular weights can be obtained, and a copolymer product with a number-average molecular weight of up to 174 kDa can be prepared at most.

[0228] Comparing Application Example 16 with Application Examples 18 and 19, it can be seen that the catalysts disclosed in the present invention have higher catalytic activity, can obtain polymers with higher molecular weights, and have more excellent catalytic effects.

[0229] Comparing Application Example 14 with Application Example 20, it can be seen that the catalysts disclosed in the present invention have excellent air stability.

[0230] Table 2

[0231]

[0232] Note: a Conv.(%) : The monomer conversion was determined by 1 1H NMR. b Turnover number (TON) = (moles of monomer consumed) / (moles of catalyst). c Turnover frequency (TOF) = (moles of monomer consumed) / (moles of catalyst · hour). d M n GPC n: Number-average molecular weight, determined by gel permeation chromatography. e Ð: Molecular weight distribution, determined by gel permeation chromatography.

[0233] It should be noted that the above embodiments are only used to illustrate the present invention, but the present invention is not limited to the above embodiments. Any simple modification, equivalent change and modification made to the above embodiments based on the technical essence of the present invention shall fall within the protection scope of the present invention.

Claims

1. A monomolecular bifunctional organic catalyst for the ring-opening copolymerization of epoxides and cyclic anhydrides, characterized in that: The structural formula is shown in the following formula (I): （Ⅰ）； In formula (I), X is selected from an alkyl boron group, and the structural formula is shown in the following formula (II-1) or (II-2): (Ⅱ-1); (II-2); In the formula: B is a boron atom; R1 is selected from an alkyl group; Indicates the connection key; The structural formula of Y is shown in the following formula (III): （Ⅲ）； In the formula: O is an oxygen atom; R2 is selected from one or more of Li, Na, K, Cs, quaternary ammonium cation, and bis(triphenylphosphine)ammonium cation; Indicates the connection key; L is selected from unsubstituted C4~C 11 alkyl.

2. The unimolecular bifunctional organic catalyst for the ring-opening copolymerization of epoxide and cyclic anhydride according to claim 1, characterized in that: R1 is selected from , or .

3. The unimolecular bifunctional organic catalyst for the ring-opening copolymerization of epoxide and cyclic anhydride according to claim 1, characterized in that: The structural formula is selected from one or more of the following formulas (I-1) to (I-14): （Ⅰ-1）； （Ⅰ-2）； （Ⅰ-3）； （Ⅰ-4）； （Ⅰ-5）； （Ⅰ-6）； （Ⅰ-7）； （Ⅰ-8）； （Ⅰ-9）； （Ⅰ-10）； （Ⅰ-11）； （Ⅰ-12）； （Ⅰ-13）； （Ⅰ-14）。 4. A method for preparing a monomolecular bifunctional organic catalyst for ring-opening copolymerization of epoxide and cyclic anhydride according to any one of claims 1 to 3, characterized in that: When R2 is selected from at least one of Li, Na, K, and Cs, the steps include: The raw material 1 having the structure of the following formula W1, the alkali metal and the solvent A are uniformly mixed to obtain a raw material solution I, and then the raw material 2 having the structure of the following formula W2 is mixed with the raw material solution I for an addition reaction to obtain the monomolecular bifunctional organic catalyst; W1; or W2; When R2 is selected from quaternary ammonium cations and / or bis(triphenylphosphine)ammonium cations, the steps include: The raw material 1 having the structure of the above formula W1, the alkali metal and the solvent A are uniformly mixed to obtain a raw material solution I, and then the raw material 2 having the structure of the above formula W2 is mixed with the raw material solution I for addition reaction to obtain an intermediate product; The intermediate product is mixed with solvent B to obtain raw material solution II, raw material 3 is mixed with solvent B to obtain raw material solution III, and raw material solution II and raw material solution III are mixed and subjected to ion exchange reaction to obtain the monomolecular bifunctional organic catalyst; The raw material 3 is selected from one or more of bis(triphenylphosphine)ammonium chloride, tetrabutylammonium chloride, and 1,3-bis(2,4,6-trimethylphenyl)imidazole chloride.

5. The method for preparing a monomolecular bifunctional organic catalyst for ring-opening copolymerization of epoxide and cyclic anhydride according to claim 4, characterized in that: The solvent A is selected from one or more of tetrahydrofuran, n-hexane, diethyl ether and methyl tert-butyl ether; The alkali metal is selected from one or more of Li, Na, K, and Cs; The raw material 1 is selected from one or more of 3-butene-1-ol, 4-pentene-1-ol, 5-hexene-1-ol, 8-nonene-1-ol, 9-decene-1-ol, and 10-undecene-1-ol; The solvent B is selected from one or more of acetonitrile, acetone, chloroform and dichloromethane.

6. The method for preparing a monomolecular bifunctional organic catalyst for ring-opening copolymerization of epoxide and cyclic anhydride according to claim 4, characterized in that: The molar ratio of raw material 1 to alkali metal is 1: (1.0-1.5); The molar ratio of raw material 1 to raw material 2 is 1:(1.0~1.5); In the raw material solution I, the concentration of raw material 1 is 0.8-1.2 mol / L; The temperature of the addition reaction is 80~100℃.

7. The method for preparing a monomolecular bifunctional organic catalyst for ring-opening copolymerization of epoxide and cyclic anhydride according to claim 4, characterized in that: The concentration of raw material solution II is 0.8~1.2 mol / L; The concentration of raw material solution III is 0.8~1.2 mol / L; The volume ratio of raw material liquid II to raw material liquid III is 1: (1.0~1.3).

8. A ring-opening copolymerization of epoxide and cyclic anhydride, characterized in that: The unimolecular bifunctional organic catalyst according to any one of claims 1 to 3 is used.

9. The ring-opening copolymerization of epoxide and cyclic anhydride according to claim 8, characterized in that: The epoxide monomer is selected from one or more of ethylene oxide, propylene oxide, butylene oxide, cyclohexene oxide, phenyl glycidyl ether, benzyl glycidyl ether, isobutylene oxide, epichlorohydrin, and styrene oxide; The cyclic anhydride monomer is selected from one or more of phthalic anhydride, maleic anhydride, succinic anhydride, glutaric anhydride, adipic anhydride, biphenyl anhydride, 3,3-tetramethyleneglutaric anhydride, 1,1-cyclohexyldiacetic anhydride, diglycolic anhydride, nadic anhydride, tetrachlorophthalic anhydride, and tetrabromophthalic anhydride.

10. The ring-opening copolymerization of epoxide and cyclic anhydride according to claim 8, characterized in that: The molar ratio of the epoxide monomer to the cyclic anhydride monomer is (2-8):1; The molar ratio of the cyclic anhydride monomer to the monomolecular bifunctional organic catalyst is (100-100000):1.

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