Polycaprolactone-poly (2-vinyl) ethylene glycol copolymer and preparation method thereof

Abstract

The invention provides a polycaprolactone-poly (2-vinyl) ethylene glycol copolymer and a preparation method thereof.The preparation method comprises the steps that raw materials are provided, and the raw materials comprise polycaprolactone containing 1-4 hydroxyl groups and further comprise 4-vinyl-1, 3-dioxocyclopent-2-ketone or vinyl ethylene oxide; the preparation method comprises the following steps: dissolving the raw materials in an organic solvent, and reacting in the presence of a palladium catalyst and a phosphine ligand to obtain the polycaprolactone-poly (2-vinyl) ethylene glycol copolymer. The preparation method disclosed by the invention has the advantages of high efficiency and high selectivity, and the prepared copolymer is relatively high in vinyl content, controllable in molecular weight and narrow in molecular weight distribution.

Description

Technical Field

[0001] The invention relates to the technical field of polymer materials, and in particular to a polycaprolactone-poly(2-vinyl) glycol copolymer and a preparation method thereof. Background Art

[0002] Polycaprolactone (PCL) is a semi-crystalline aliphatic polyester. Due to its excellent biocompatibility, biodegradability and mechanical properties, it is widely used in the field of biomedical materials, such as drug delivery systems, tissue engineering scaffolds and absorbable sutures (Prog. Polym. Sci., 2019, 96, 1-20; Chem. Soc. Rev., 2009, 38, 3484-3504). However, although PCL has good biocompatibility, its high crystallinity and melting temperature limit its use in certain applications that require low temperature processing or high flexibility (J. Biomed. Mater. Res., 2022; 110 (6): 1479-1503.). In addition, the hydrophobicity of PCL in aqueous solution may lead to nonspecific adsorption of proteins, thereby inducing an immune response and reducing the biocompatibility and functionality of the material (Annu. Rev. Mater. Res. 2001, 31, 81-110; Angew. Chem. Int. Edit. 2014, 53, 8004-8031). Therefore, how to regulate the crystallinity, melting temperature and surface properties of PCL while maintaining its basic properties has become an important topic in materials science research.

[0003] In recent years, chemical grafting and copolymerization modification technology has gradually become one of the important means to improve the performance of PCL. The functionalization method of PCL mainly focuses on the chemical modification of its end group or main chain structure. By introducing functional groups (such as vinyl, carboxyl, methacrylate, thiol, etc.), it can be cross-linked with other polymers or small molecule compounds, thereby enhancing the mechanical properties and thermal stability of PCL and giving it new functional properties (Polym.Sci.A Polym.Chem., 2005, 43: 1369-1381; Polym.Chem., 2012, 3, 2956-2963; Macromolecules 2014, 47, 1828-1836.). For example, by introducing vinyl at the end of the PCL chain, the cross-linkability of the material can be significantly improved, thereby improving its thermodynamic properties and mechanical strength (Adv.Mater.2023, 35, 2210136.).

[0004] However, traditional PCL grafting is usually limited to a single functional group or a small number of reactive groups, which limits the precise regulation of material properties. Therefore, exploring multifunctional grafting monomers and achieving fine regulation of PCL structure and properties by precisely controlling their grafting amount and distribution is an important direction of current research.

[0005] After searching, it was found that the Chinese invention patent with application publication number CN117510826A discloses a vinyl functional polyether polyol and a preparation method thereof, which uses a compound containing 1 to 4 hydroxyl groups and 4-vinyl-1,3-dioxolane-2-one or vinyl oxirane as raw materials, dissolves them in an organic solvent, and reacts under the action of a palladium catalyst and a phosphine ligand to obtain a vinyl functional polyether polyol. The patent prepares vinyl functional polyether polyols, which are completely different from the biomedical application field of polycaprolactone and cannot achieve modification of polycaprolactone. Summary of the invention

[0006] In view of the defects in the prior art, the object of the present invention is to provide a polycaprolactone-poly (2-vinyl) glycol copolymer and a preparation method thereof.

[0007] Poly(2-vinyl) glycol (PVEG) is a polymer containing vinyl groups. By using PCL to initiate polymerization, a certain number of vinyl groups can be introduced at the chain end of PCL, giving it a wider range of functional modification potential. PCL-PVEG copolymers can not only maintain the excellent biocompatibility and water solubility of PCL, but also reduce crystallinity, improve thermal stability, enhance mechanical properties, and give the material cross-linkability and shape memory properties by regulating the content of PVEG. In addition, the vinyl functionalization of PCL also provides the possibility for subsequent cross-linking reactions and further modifications, giving it greater flexibility in controllable polymer structure design.

[0008] Based on this, the present invention provides a method for preparing functionalized PCL-PVEG copolymers by a palladium catalytic system. The method can effectively control the molecular weight and vinyl content of the copolymer, significantly improve the functional properties of the material, and is suitable for high-demand industrial applications and the field of biomedical materials, especially in shape memory materials.

[0009] According to one aspect of the present invention, a polycaprolactone-poly(2-vinyl)ethylene glycol copolymer is provided, wherein the structural formula of the polycaprolactone-poly(2-vinyl)ethylene glycol copolymer is shown in any one of the following:

[0010]

[0011]

[0012] Wherein R1 is selected from hydrogen, C1-C 20 Alkyl, benzyl, C6-C 14 Aryl, C6-C 14 Oxygen heterocycle, C6-C 14 Nitrogen heterocycle, C6-C 14 Sulfur heterocycle, C5-C 20 Oxyheterochain, C5-C 20 Azachain and C5-C 20 Any of the sulfur chains;

[0013] R2, R3 and R4 are selected from C1-C 20 Alkyl, benzyl, C6-C 14 Aryl, C6-C 14 Oxygen heterocycle, C6-C 14 Nitrogen heterocycle, C6-C 14 Sulfur heterocycle, C5-C 20 Oxyheterochain, C5-C 20 Azachain and C5-C 20 Any of the sulfur chains;

[0014] m, m1, m2, m3, m4, n, n1, n2, n3 and n4 are all positive integers, and m, m1, m2, m3, m4, n, n1, n2, n3, n4 ≥ 1.

[0015] Furthermore, the number average molecular weight of the polycaprolactone-poly(2-vinyl)ethylene glycol copolymer is 500 to 100,000, and the double bond content is 0.10 mmol / g to 6.40 mmol / g.

[0016] Furthermore, the polydispersity PDI of the polycaprolactone-poly(2-vinyl)glycol copolymer is 1.13 to 1.26. The polydispersity of the polycaprolactone-poly(2-vinyl)glycol copolymer provided by the present invention is close to 1, indicating that the molecular weight of the polymer is relatively uniform and concentrated, and it is easy to control the quality of the material performance when it is used in the preparation of materials in the later stage.

[0017] According to another aspect of the present invention, there is provided a method for preparing the above-mentioned polycaprolactone-poly(2-vinyl)glycol copolymer, the method comprising:

[0018] Providing a raw material, the raw material includes polycaprolactone containing 1 to 4 hydroxyl groups, and also includes 4-vinyl-1,3-dioxolane-2-one or vinyl oxirane;

[0019] The raw materials are dissolved in an organic solvent, and reacted in the presence of a palladium catalyst and a phosphine ligand to obtain a polycaprolactone-poly(2-vinyl)ethylene glycol copolymer.

[0020] Optionally, the palladium catalyst is selected from any one of tris(dibenzylideneacetone)dipalladium(0)-chloroform adduct, tris(dibenzylideneacetone)dipalladium(0), bis(dibenzylideneacetone)dipalladium(0), bis(triphenylphosphine)palladium chloride, palladium acetate, palladium oxide, tetrakis(triphenylphosphine)palladium, palladium chloride, palladium nitrate, bis(acetonitrile)dichloropalladium(II), 1,1'-bis(diphenylphosphino)ferrocenedichloropalladium, bis(benzonitrile)dichloropalladium, 1,4-bis(diphenylphosphine)butane-palladium chloride and allylpalladium chloride(II) dimer. Preferably, the palladium catalyst is selected from tris(dibenzylideneacetone)dipalladium(0)-chloroform adduct or tris(dibenzylideneacetone)dipalladium(0).

[0021] The palladium catalyst selects 0-valent or 2-valent oxides. By using a palladium source with moderate catalytic activity, it can effectively activate the reaction and avoid side reactions (such as decarbonylation and β-hydrogen elimination); at the same time, the efficient catalyst needs to maintain stability under the reaction conditions to avoid deactivation. Using the above substances as palladium catalysts can ensure the conversion rate and selectivity of the reaction.

[0022] Optionally, the phosphine ligand is selected from any one of tri(2-furyl)phosphine, 1,1'-binaphthyl-2,2'-bisdiphenylphosphine, bis(2-diphenylphosphinophenyl)ether, 1,2-bis(diphenylphosphino)ethane, 1,3-bis(diphenylphosphino)propane, 1,4-bis(diphenylphosphino)butane, tri-tert-butylphosphine, tri(2-methoxyphenyl)phosphine, tri(3-methoxyphenyl)phosphine, 1,1-bis(diphenylphosphino)ferrocene, tri(4-trifluoromethylphenyl)phosphine, tri-tert-butylphosphine tetrafluoroborate, tri(p-tolyl)phosphine and tri(m-tolyl)phosphine. Preferably, the phosphine ligand is selected from 1,1'-binaphthyl-2,2'-bisdiphenylphosphine or bis(2-diphenylphosphinophenyl)ether.

[0023] The phosphine ligand is set according to factors such as electronic effect, spatial effect and solubility. Using the above substances as phosphine ligands can regulate the electronic and stereo environment of the palladium center, thereby improving the catalytic activity and reaction selectivity; and enhancing the stability of the catalyst and extending the catalytic life.

[0024] Optionally, the organic solvent is selected from any one of 1,4-dioxane, methyl tert-butyl ether, benzene, toluene, tetrahydrofuran, dichloromethane, ether, acetonitrile and acetone. Preferably, the solvent is selected from tetrahydrofuran or toluene.

[0025] The organic solvent is set according to factors such as solubility, polarity selection, reaction compatibility, boiling point and operating temperature. Using the above substances as organic solvents can provide good solubility and reaction environment, increase the reaction rate; at the same time, improve the reaction selectivity, such as stabilizing specific intermediates through solvent effects; and prevent catalyst deactivation and prolong the reaction time.

[0026] Optionally, the molar ratio of the polycaprolactone-poly(2-vinyl)glycol copolymer containing 1 to 4 hydroxyl groups to 4-vinyl-1,3-dioxolane-2-one or vinyl oxirane is 1:n, wherein n is the number of repetitions of the chemical structure (2-vinyl)glycol fragment in the structural formula of the polycaprolactone-poly(2-vinyl)glycol copolymer. The amount of the palladium catalyst is 0.15% (mol) of the amount of vinyl carbonate (VEC), and the amount of the phosphine ligand and triethyl boron is 0.3% (mol) of the amount of vinyl carbonate (VEC).

[0027] As shown in the following reaction equation (I), polycaprolactone containing one hydroxyl group and 4-vinyl-1,3-dioxolane-2-one or vinyl oxirane are used as raw materials, dissolved in an organic solvent, and the reaction is controlled at 10-70° C. and stirred for 1-8 hours under the action of a palladium catalyst and a phosphine ligand to obtain a polycaprolactone-poly(2-vinyl)ethylene glycol copolymer having a structure of formula (1).

[0028]

[0029] As shown in the following reaction equation (II), polycaprolactone containing two hydroxyl groups and 4-vinyl-1,3-dioxolane-2-one or vinyl oxirane are used as raw materials, dissolved in an organic solvent, and the reaction is controlled to stir at 10-70° C. for 1-8 hours under the action of a palladium catalyst and a phosphine ligand to prepare a polycaprolactone-poly(2-vinyl)ethylene glycol copolymer having a structure of formula (2).

[0030]

[0031] As shown in the following reaction equation (III), polycaprolactone containing three hydroxyl groups and 4-vinyl-1,3-dioxolane-2-one or vinyl oxirane are used as raw materials, dissolved in an organic solvent, and the reaction is controlled to stir at 10-70° C. for 1-8 hours under the action of a palladium catalyst and a phosphine ligand to prepare a polycaprolactone-poly(2-vinyl)ethylene glycol copolymer having a structure of formula (3).

[0032]

[0033] As shown in the following reaction formula (IV), polycaprolactone containing four hydroxyl groups and 4-vinyl-1,3-dioxolane-2-one or vinyl oxirane are used as raw materials, dissolved in an organic solvent, and the reaction is controlled at 10-70° C. and stirred for 1-8 hours under the action of a palladium catalyst and a phosphine ligand to prepare a polycaprolactone-poly(2-vinyl)ethylene glycol copolymer having a structural formula (4).

[0034]

[0035] Optionally, the reaction temperature is 10-70° C., and the reaction time is 1-8 hours.

[0036] Preferably, the reaction temperature is 10-20°C.

[0037] Preferably, the reaction time is 2-6 hours.

[0038] The reaction temperature is set according to factors such as the difficulty of operation of the preparation process and the preparation effect. The closer the reaction is to room temperature, the easier it is to operate. The temperature will also affect the molecular weight distribution of the prepared polymer compound. Specifically, the temperature affects the control of the kinetics and chain growth rate, the coordination of the initiation and growth stages, the solubility and diffusivity of the solvent, and the inhibition of side reactions. The above temperature setting of the present invention can optimize the molecular weight distribution, improve the uniformity of grafting, inhibit side reactions, and be easy to operate and improve the preparation efficiency. The reaction time affects the efficiency and effect of the preparation. For the grafting efficiency, if the time is too short, the hydroxyl groups on the polycaprolactone molecules are not fully reacted with VEC, resulting in a low grafting rate and insufficient functionalization of the product. Properly extending the reaction time can improve the grafting efficiency and make the reaction close to complete, but too long a time may cause side reactions (such as polymerization) or degradation, and the lower the preparation efficiency, so the appropriate reaction time is very important for the preparation efficiency and effect. For the uniformity and controllability of the molecular structure, too short a time may lead to uneven grafting and form an unevenly distributed product; too long a time is easy to generate an over-grafted branched or cross-linked structure. The appropriate time can ensure the uniformity and controllability of the product structure (such as controlling the grafting rate and functionalization density). The above reaction time of the present invention can ensure high yield and high selectivity, and control the molecular weight and functionalization degree, thereby improving the overall preparation efficiency.

[0039] The present invention uses 4-vinyl-1,3-dioxolane-2-one or vinyl oxirane as raw materials, uses various polycaprolactones as initiators, and prepares such polycaprolactone-poly(2-vinyl)ethylene glycol copolymers under palladium catalysis. The detailed synthesis method is: polycaprolactone, a catalyst and a phosphine ligand are added to a reactor, vacuum dehydrated, replaced with N2 three times, an organic solvent is added, and stirred until the polycaprolactone is completely dissolved. According to the vinyl content of the copolymer to be prepared, a corresponding molar amount of 4-vinyl-1,3-dioxolane-2-one or vinyl oxirane is added, wherein the molar ratio of polycaprolactone containing 1 to 4 hydroxyl groups to 4-vinyl-1,3-dioxolane-2-one or vinyl oxirane is 1:n, and the reaction is controlled at 10-70°C and stirred for 1-8 hours.

[0040] After the reaction is finished, the catalyst and the phosphine ligand are removed to obtain the polycaprolactone-poly(2-vinyl)glycol copolymer. The present invention does not require high temperature and high pressure reaction conditions, has a short reaction time, and has a high efficiency and high selectivity in the preparation method, controllable molecular weight, and narrow molecular weight distribution.

[0041] The polycaprolactone-poly(2-vinyl) glycol copolymer prepared by the present invention can be applied to the fields of hydrophilic / hydrophobic materials, drug carriers, antibacterial materials, shape memory materials, etc. through post-functionalization, and can be used in the preparation of photocurable coating materials and the field of functionalized polyurethane synthesis.

[0042] Compared with the prior art, the present invention has at least one of the following beneficial effects:

[0043] The polycaprolactone-poly(2-vinyl) glycol copolymer provided by the present invention has a number average molecular weight of 500 to 30,000, a high vinyl content, a controllable molecular weight, and a narrow molecular weight distribution. The polycaprolactone-poly(2-vinyl) glycol copolymer can be used in the fields of hydrophilic / hydrophobic materials, drug carriers, antibacterial materials, phase change materials, shape memory materials, and the like.

[0044] The present invention uses hydroxyl-containing polycaprolactone as an initiator, 4-vinyl-1,3-dioxolane-2-one or vinyl oxirane as a raw material, and efficiently prepares polycaprolactone-poly(2-vinyl)ethylene glycol copolymer under the action of a palladium catalyst and a phosphine ligand, which can greatly reduce the reaction steps and the reaction time. The preparation method of the present invention has the advantages of high efficiency and high selectivity. DETAILED DESCRIPTION

[0045] The present invention is described in detail below in conjunction with specific embodiments. The following embodiments will help those skilled in the art to further understand the present invention, but are not intended to limit the present invention in any form. It should be noted that, for those of ordinary skill in the art, several variations and improvements may be made without departing from the concept of the present invention. These all belong to the protection scope of the present invention.

[0046] Example 1

[0047] The reaction formula in this embodiment is as follows:

[0048]

[0049] Polycaprolactone monoalcohol (6.0 g, 1 mmol), tris(dibenzylideneacetone)dipalladium(0)-chloroform adduct (62.1 mg, 0.06 mmol), and phosphine ligand bis(2-diphenylphosphinophenyl)ether (64.6 mg, 0.12 mmol) were added to the reactor, vacuum dehydrated, and replaced with N2 three times, 4-vinyl-1,3-dioxolane-2-one (4564.0 mg, 40.0 mmol), BEt3 (120 μL of 1 mol·L -1 in THF solution) and 12 mL of tetrahydrofuran solvent, and the reaction was controlled at 10°C and stirred for 6 hours.

[0050] After the reaction, the catalyst and phosphine ligand were removed to obtain polycaprolactone-poly(2-vinyl)ethylene glycol copolymer with a yield of 80%, a number average molecular weight Mn: 8000, Mw / Mn: 1.11, a vinyl content of 2.75±0.10mmol / g, and n, m≥1.

[0051] Example 2

[0052] The reaction formula in this embodiment is as follows:

[0053]

[0054] Polycaprolactone diol (9.4 g, 1 mmol), tris(dibenzylideneacetone)dipalladium(0)-chloroform adduct (62.1 mg, 0.06 mmol), and phosphine ligand bis(2-diphenylphosphinophenyl)ether (64.6 mg, 0.12 mmol) were added to the reactor, vacuum dehydrated, and replaced with N2 three times, 4-vinyl-1,3-dioxolane-2-one (4564.0 mg, 40.0 mmol), BEt3 (120 μL of 1 mol·L -1 in THF solution) and 18.8 mL of tetrahydrofuran solvent, and the reaction was controlled at 10°C and stirred for 6 hours.

[0055] After the reaction is completed, the catalyst and phosphine ligand are removed to obtain polycaprolactone-poly(2-vinyl)ethylene glycol copolymer with a yield of 90%, a number average molecular weight Mn: 11200, Mw / Mn: 1.26, a vinyl content of 1.52±0.06mmol / g, and m1, m2, n1 and n2≥1.

[0056] Example 3

[0057] The reaction formula in this embodiment is as follows:

[0058]

[0059] Polycaprolactone diol (8.0 g, 1 mmol), tris(dibenzylideneacetone)dipalladium(0)-chloroform adduct (62.1 mg, 0.06 mmol), and phosphine ligand bis(2-diphenylphosphinophenyl)ether (64.6 mg, 0.12 mmol) were added to the reactor, vacuum dehydrated, and replaced with N2 three times, 4-vinyl-1,3-dioxolane-2-one (4564.0 mg, 40.0 mmol), BEt3 (120 μL of 1 mol·L -1 in THF solution) and 16 mL of tetrahydrofuran solvent, and the reaction was controlled at 10°C and stirred for 6 hours.

[0060] After the reaction is completed, the catalyst and the phosphine ligand are removed to obtain a polycaprolactone-poly(2-vinyl)ethylene glycol copolymer with a yield of 80%, a number average molecular weight Mn: 9200, Mw / Mn: 1.23, a vinyl content of 1.79±0.04mmol / g, and m1, m2, m3, n1, n2 and n3≥1.

[0061] Example 4

[0062] The reaction formula in this embodiment is as follows:

[0063]

[0064] Polycaprolactone tetraol (9.2 g, 1 mmol), tris(dibenzylideneacetone)dipalladium(0)-chloroform adduct (62.1 mg, 0.06 mmol), and phosphine ligand bis(2-diphenylphosphinophenyl)ether (64.6 mg, 0.12 mmol) were added to the reactor, vacuum dehydrated, and replaced with N2 three times, 4-vinyl-1,3-dioxolane-2-one (4564.0 mg, 40.0 mmol), BEt3 (120 μL of 1 mol·L -1 in THF solution) and 18.4 mL of tetrahydrofuran solvent, and the reaction was controlled at 10°C and stirred for 6 hours.

[0065] After the reaction is completed, the catalyst and the phosphine ligand are removed to obtain a polycaprolactone-poly (2-vinyl) glycol copolymer with a yield of 80%, a number average molecular weight Mn: 11100, Mw / Mn: 1.21, a vinyl content of 1.92±0.02mmol / g, and m1, m2, m3, m4, n1, n2, n3 and n4≥1.

[0066] Example 5

[0067] The reaction formula in this embodiment is as follows:

[0068]

[0069] Polycaprolactone tetraol (9.2 g, 1 mmol), tris(dibenzylideneacetone)dipalladium(0)-chloroform adduct (124.4 mg, 0.12 mmol), and phosphine ligand bis(2-diphenylphosphinophenyl)ether (129.2 mg, 0.24 mmol) were added to the reactor, vacuum dehydrated, and replaced with N2 three times, 4-vinyl-1,3-dioxolane-2-one (9128.0 mg, 80.0 mmol), BEt3 (240 μL of 1 mol·L -1 in THF solution) and 18.4 mL of tetrahydrofuran solvent, and the reaction was controlled at 10°C and stirred for 6 hours.

[0070] After the reaction is completed, the catalyst and the phosphine ligand are removed to obtain a polycaprolactone-poly(2-vinyl)glycol copolymer with a yield of 70%, a number average molecular weight Mn: 14600, Mw / Mn: 1.13, a vinyl content of 3.20±0.15mmol / g, and m1, m2, m3, m4, n1, n2, n3 and n4≥1.

[0071] Example 6

[0072] The reaction formula in this embodiment is as follows:

[0073]

[0074] Polycaprolactone diol (9.4 g, 1 mmol), tris(dibenzylideneacetone)dipalladium(0)-chloroform adduct (15.5 mg, 0.015 mmol), and phosphine ligand bis(2-diphenylphosphinophenyl)ether (16.2 mg, 0.03 mmol) were added to the reactor, vacuum dehydrated, and replaced with N2 three times, 4-vinyl-1,3-dioxolane-2-one (1141.0 mg, 10.0 mmol), BEt3 (30 μL of 1 mol·L -1 in THF solution) and 18.8 mL of tetrahydrofuran solvent, and the reaction was controlled at 10°C and stirred for 6 hours.

[0075] After the reaction is completed, the catalyst and phosphine ligand are removed to obtain polycaprolactone-poly(2-vinyl)ethylene glycol copolymer with a yield of 95%, a number average molecular weight Mn: 9800, Mw / Mn: 1.24, a vinyl content of 0.43±0.02mmol / g, and m1, m2, n1 and n2≥1.

[0076] Example 7

[0077] The reaction formula in this embodiment is as follows:

[0078]

[0079] Polycaprolactone diol (9.4 g, 1 mmol), tris(dibenzylideneacetone)dipalladium(0)-chloroform adduct (31.1 mg, 0.03 mmol), and phosphine ligand bis(2-diphenylphosphinophenyl)ether (32.4 mg, 0.06 mmol) were added to the reactor, vacuum dehydrated, and replaced with N2 three times, 4-vinyl-1,3-dioxolane-2-one (2282.0 mg, 20.0 mmol), BEt3 (60 μL of 1 mol·L -1 in THF solution) and 18.8 mL of tetrahydrofuran solvent, and the reaction was controlled at 10°C and stirred for 6 hours.

[0080] After the reaction is completed, the catalyst and phosphine ligand are removed to obtain polycaprolactone-poly(2-vinyl)ethylene glycol copolymer with a yield of 93%, a number average molecular weight Mn: 10500, Mw / Mn: 1.20, a vinyl content of 1.04±0.03mmol / g, and m1, m2, n1 and n2≥1.

[0081] Example 8

[0082] The reaction formula in this embodiment is as follows:

[0083]

[0084] Polycaprolactone tetraol (6.0 g, 1 mmol), tris(dibenzylideneacetone)dipalladium(0)-chloroform adduct (62.1 mg, 0.06 mmol), and phosphine ligand bis(2-diphenylphosphinophenyl)ether (64.6 mg, 0.12 mmol) were added to the reactor, vacuum dehydrated, and replaced with N2 three times, 4-vinyl-1,3-dioxolane-2-one (4564.0 mg, 40.0 mmol), BEt3 (120 μL of 1 mol·L -1 in THF solution) and 12 mL of tetrahydrofuran solvent, and the reaction was controlled at 10°C and stirred for 6 hours.

[0085] After the reaction is completed, the catalyst and the phosphine ligand are removed to obtain a polycaprolactone-poly (2-vinyl) glycol copolymer with a yield of 70%, a number average molecular weight Mn: 8200, Mw / Mn: 1.12, a vinyl content of 2.24±0.07mmol / g, and m1, m2, m3, m4, n1, n2, n3 and n4≥1.

[0086] The above describes the specific embodiments of the present invention. It should be understood that the present invention is not limited to the above specific embodiments, and those skilled in the art can make various modifications or variations within the scope of the claims, which does not affect the essence of the present invention. The above preferred features can be used in any combination without conflicting with each other.

Claims

1. A polycaprolactone-poly(2-vinyl)glycol copolymer, characterized in that: The structural formula of the polycaprolactone-poly(2-vinyl) glycol copolymer is shown in any one of the following: Wherein R1 is selected from hydrogen, C1-C 20 Alkyl, benzyl, C6-C 14 Aryl, C6-C 14 Oxygen heterocycle, C6-C 14 Nitrogen heterocycle, C6-C 14 Sulfur heterocycle, C5-C 20 Oxyheterochain, C5-C 20 Azachain and C5-C 20 Any of the sulfur chains; R2, R3 and R4 are selected from C1-C 20 Alkyl, benzyl, C6-C 14 Aryl, C6-C 14 Oxygen heterocycle, C6-C 14 Nitrogen heterocycle, C6-C 14 Sulfur heterocycle, C5-C 20 Oxyheterochain, C5-C 20 Azachain and C5-C 20 Any of the sulfur chains; m, m1, m2, m3, m4, n, n1, n2, n3 and n4 are all positive integers, and m, m1, m2, m3, m4, n, n1, n2, n3, n4 ≥ 1.

2. The polycaprolactone-poly(2-vinyl)glycol copolymer according to claim 1, characterized in that The number average molecular weight of the polycaprolactone-poly(2-vinyl)ethylene glycol copolymer is 500 to 100,000, and the double bond content is 0.10 mmol / g to 6.40 mmol / g.

3. A method for preparing the polycaprolactone-poly(2-vinyl)glycol copolymer according to claim 1 or 2, characterized in that: include: Providing a raw material, the raw material includes polycaprolactone containing 1 to 4 hydroxyl groups, and also includes 4-vinyl-1,3-dioxolane-2-one or vinyl oxirane; The raw materials are dissolved in an organic solvent, and reacted in the presence of a palladium catalyst and a phosphine ligand to obtain a polycaprolactone-poly(2-vinyl)ethylene glycol copolymer.

4. The preparation method according to claim 3, characterized in that: The palladium catalyst is selected from any one of tris(dibenzylideneacetone)dipalladium(0)-chloroform adduct, tris(dibenzylideneacetone)dipalladium(0), bis(dibenzylideneacetone)dipalladium(0), bis(triphenylphosphine)palladium chloride, palladium acetate, palladium oxide, tetrakis(triphenylphosphine)palladium, palladium chloride, palladium nitrate, bis(acetonitrile)palladium(II) dichloride, 1,1'-bis(diphenylphosphino)ferrocenepalladium(II) dichloride, bis(benzonitrile)palladium(II) dichloride, 1,4-bis(diphenylphosphino)butane-palladium chloride and allylpalladium(II) chloride dimer.

5. The preparation method according to claim 3, characterized in that: The phosphine ligand is selected from any one of tri(2-furyl)phosphine, 1,1'-binaphthyl-2,2'-bisdiphenylphosphine, bis(2-diphenylphosphinophenyl)ether, 1,2-bis(diphenylphosphine)ethane, 1,3-bis(diphenylphosphine)propane, 1,4-bis(diphenylphosphine)butane, tri-tert-butylphosphine, tri(2-methoxyphenyl)phosphine, tri(3-methoxyphenyl)phosphine, 1,1-bis(diphenylphosphino)ferrocene, tri(4-trifluoromethylphenyl)phosphine, tri-tert-butylphosphine tetrafluoroborate, tri(p-tolyl)phosphine and tri(m-tolyl)phosphine.

6. The preparation method according to claim 3, characterized in that: The organic solvent is selected from any one of 1,4-dioxane, methyl tert-butyl ether, benzene, toluene, tetrahydrofuran, dichloromethane, ethyl ether, acetonitrile and acetone.

7. The preparation method according to claim 3, characterized in that: The molar ratio of the polycaprolactone-poly(2-vinyl)glycol copolymer containing 1 to 4 hydroxyl groups to 4-vinyl-1,3-dioxolane-2-one or vinyl oxirane is 1:n, wherein n is the number of repetitions of the chemical structure (2-vinyl)glycol fragment in the structural formula of the polycaprolactone-poly(2-vinyl)glycol copolymer.

8. The preparation method according to claim 3, characterized in that: The reaction temperature is 10-70°C, and the reaction time is 1-8 hours.

9. The preparation method according to claim 8, characterized in that: The reaction temperature is 10-20°C.

10. The preparation method according to claim 8, characterized in that: The reaction time is 2-6 hours.

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