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

Abstract

The invention discloses a polyethylene glycol-poly (2-vinyl) ethylene glycol copolymer and a preparation method thereof, and relates to the technical field of high polymer materials, and the structure of the polyethylene glycol-poly (2-vinyl) ethylene glycol copolymer is selected from any one of the following structural formulas: # imgabs0. The preparation method comprises the following steps: taking hydroxyl-containing polyethylene glycol and 4-vinyl-1, 3-dioxocyclopent-2-ketone or vinyl ethylene oxide as raw materials; under the action of a palladium catalyst and a phosphine ligand, the polyethylene glycol-poly (2-vinyl) glycol copolymer is efficiently prepared and can be used in the fields of hydrophilic / hydrophobic materials, drug carriers, antibacterial materials, phase change materials, shape memory materials and the like.

Description

Technical Field

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

[0002] Polyethylene glycol (PEG) has been widely used in medical implants, drug carriers and phase change energy storage materials due to its good biocompatibility, low toxicity, biodegradability and excellent solubility (Angew. Chem. Int. Ed. 2010, 49, 6288.). However, the high crystallinity, low mechanical strength and thermal stability of PEG limit its further application in the field of high-performance materials. In recent years, how to improve the mechanical properties, thermal stability and functionality of PEG through chemical modification has become one of the research hotspots (ACS Macro Lett. 2022, 11, 805; Adv. Funct. Mater. 2024, 2409487; Angew. Chem. Int. Ed., 50: 7988).

[0003] The functionalization methods of PEG mainly focus on the chemical modification of its end groups or main chain structures. By introducing functional groups (such as vinyl, carboxyl, amino, aldehyde, etc.), it can be cross-linked with other polymers or small molecule compounds, thereby enhancing the mechanical properties and thermal stability of PEG and giving it new functional properties (CN113631631B; CN114479059B; CN113896882A). For example, by introducing vinyl groups at the ends of PEG chains, the cross-linkability of the material can be significantly improved, thereby improving its thermodynamic properties and mechanical strength.

[0004] Poly(2-vinyl)ethylene glycol (PVEG) is a polymer containing vinyl groups. By using PEG to initiate polymerization, a certain number of vinyl groups can be introduced at the chain end of PEG, giving it a wider range of functional modification potential. PEG-PVEG copolymers can not only maintain the excellent biocompatibility and water solubility of PEG, 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 PEG also provides the possibility for subsequent cross-linking reactions and further modifications, giving it higher flexibility in controllable polymer structure design.

[0005] To this end, the present invention provides a polyethylene glycol-poly (2-vinyl) glycol copolymer and a method for preparing a functionalized PEG-PVEG copolymer using a palladium catalytic system. The method can effectively control the molecular weight and vinyl content of the copolymer, significantly improve the thermal stability, mechanical properties and functional properties of the material, and is suitable for high-demand industrial applications and the field of biomedical materials, especially in shape memory materials and solid-solid phase change energy storage materials. Summary of the invention

[0006] In view of the defects in the prior art, the first aspect of the present invention is to provide a polyethylene glycol-poly (2-vinyl) glycol copolymer.

[0007] The technical solution adopted by the present invention is as follows:

[0008] A polyethylene glycol-poly (2-vinyl) glycol copolymer, whose structure is selected from any one of the following structural formulas:

[0009]

[0010] Where:

[0011] 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 one of the sulfur hetero chains; m, n, n1 and n2 are all positive integers, and m, n, n1 and n2 ≥ 1.

[0012] The number average molecular weight of the polyethylene glycol-poly (2-vinyl) glycol copolymer is 500 to 30000, and the double bond content is 0.33 mmol / g to 6.14 mmol / g. The polydispersity PDI of the polyethylene glycol-poly (2-vinyl) glycol copolymer is 1.03 to 1.08. The polydispersity of the polyethylene glycol-poly (2-vinyl) glycol copolymer of the present invention is close to 1, indicating that the molecular weight of the polymer is relatively uniform and concentrated, and the deviation from the theoretically designed polymer size is small. It is easy to control the quality of the material performance when it is used in the preparation of materials in the later stage.

[0013] The second aspect of the present invention is to provide a method for preparing a polyethylene glycol-poly (2-vinyl) glycol copolymer, comprising the following steps: using polyethylene glycol containing 1 or 2 hydroxyl groups and 4-vinyl-1,3-dioxolane-2-one or vinyl oxirane as raw materials, dissolving them in an organic solvent, and reacting in the presence of a palladium catalyst and a phosphine ligand to obtain a polyethylene glycol-poly (2-vinyl) glycol copolymer.

[0014] Further:

[0015] The polyethylene glycol is selected from any one of polyethylene glycols with a molecular weight of 400 to 25,000, preferably polyethylene glycol with a molecular weight of 500, 1,000, 2,000, 4,000, 6,000, 8,000, 10,000 or 20,000.

[0016] 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(diphenylphosphine)butane-palladium chloride and allylpalladium(II) chloride dimer; preferably, the palladium catalyst is selected from any one of tris(dibenzylideneacetone)dipalladium(0)-chloroform adduct and tris(dibenzylideneacetone)dipalladium(0).

[0017] 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 any one of 1,1'-binaphthyl-2,2'-bisdiphenylphosphine and bis(2-diphenylphosphinophenyl)ether.

[0018] 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 one of tetrahydrofuran and ether.

[0019] The reaction temperature is set according to factors such as the difficulty of the preparation process and the preparation effect. The closer the reaction is to room temperature, the easier it is to operate. The temperature also affects the molecular weight distribution of the prepared polymer compound. Optionally, the reaction temperature is 10-70°C; preferably, the reaction temperature is 10-20°C.

[0020] The reaction time affects the efficiency and effect of the preparation. The shorter the time, the more violent the reaction, which is inconvenient to control the reaction. The longer the time, the lower the preparation efficiency. Therefore, the appropriate reaction time is very important for the preparation efficiency and effect. Optionally, the reaction time is 1-8 hours; preferably, the reaction time is 2-6 hours.

[0021] Furthermore, the molar ratio of the polyethylene glycol 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 polyethylene glycol-poly (2-vinyl) glycol copolymer.

[0022] As shown in the following reaction equation (1), polyethylene glycol 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 polyethylene glycol-poly(2-vinyl)ethylene glycol copolymer having a structural formula (I).

[0023]

[0024] As shown in the following reaction equation (2), polyethylene glycol 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 polyethylene glycol-poly (2-vinyl) glycol copolymer having a structural formula (II).

[0025]

[0026] The third aspect of the present invention is to provide an application of a polyethylene glycol-poly (2-vinyl) glycol copolymer. The polyethylene glycol-poly (2-vinyl) glycol copolymer prepared by the present invention can be applied to the fields of hydrophilic / hydrophobic materials, drug carriers, antibacterial materials, phase change 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.

[0027] Compared with the prior art, the present invention has at least one of the following beneficial effects:

[0028] The above-mentioned preferred conditions of the present invention can be used alone or in any combination without conflict.

[0029] The invention uses hydroxyl-containing polyethylene glycol and 4-vinyl-1,3-dioxolane-2-one or vinyl oxirane as raw materials, and efficiently prepares polyethylene glycol-poly (2-vinyl) glycol copolymer under the action of palladium catalyst and phosphine ligand, which can greatly reduce the reaction steps and the reaction time. The prepared polyethylene glycol-poly (2-vinyl) glycol copolymer has a number average molecular weight of 500 to 30000. The polyethylene glycol-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. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 These are the NMR and IR spectra of the polyethylene glycol-poly(2-vinyl)ethylene glycol copolymer prepared in Example 1.

[0031] Figure 2 This is the NMR spectrum of the polyethylene glycol-poly(2-vinyl)ethylene glycol copolymer prepared in Example 3.

[0032] Figure 3 This is the NMR spectrum of the polyethylene glycol-poly(2-vinyl)ethylene glycol copolymer prepared in Example 4.

[0033] Figure 4 This is the NMR spectrum of the polyethylene glycol-poly(2-vinyl)ethylene glycol copolymer prepared in Example 5.

[0034] Figure 5 This is the NMR spectrum of the polyethylene glycol-poly(2-vinyl)ethylene glycol copolymer prepared in Example 6.

[0035] Figure 6 This is the NMR spectrum of the polyethylene glycol-poly(2-vinyl)ethylene glycol copolymer prepared in Example 15. DETAILED DESCRIPTION

[0036] 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.

[0037] Example 1

[0038] Polyethylene glycol 10000 (60.0 g, 6 mmol, Mn: 12600, Mw / Mn: 1.06), tris(dibenzylideneacetone)dipalladium(0)-chloroform adduct (373.6 mg, 0.15 mol% for VEC), and phosphine ligand bis(2-diphenylphosphinophenyl)ether (387.2 mg, 0.3 mol% for VEC) were added into the reactor, vacuum dehydrated, and replaced with N2 three times, and BEt3 (720 μL of 1 mol·L -1 in THF solution, 0.3mol% for VEC) and 120mL of dichloromethane solvent, after the polyethylene glycol is dissolved, 4-vinyl-1,3-dioxolane-2-one (27384.0mg, 240mmol, 40eq.) is added, and the reaction is controlled at 10°C and stirred for 6 hours. After the reaction is completed, the catalyst and phosphine ligand are removed to obtain polyethylene glycol-poly (2-vinyl) ethylene glycol copolymer with a yield of 81%, a vinyl content of 1.24±0.02mmol / g, a number average molecular weight Mn: 14200, a polydispersity Mw / Mn: 1.06, and n1, n2≥1.

[0039] The reaction formula involved in this embodiment is as follows:

[0040]

[0041] Product Confirmation:

[0042] Figure 1 The NMR and IR spectra of the polyethylene glycol-poly(2-vinyl) glycol copolymer prepared in this example are as follows: Figure 1 (A) NMR spectrum and Figure 1 The infrared spectrum of (B) shows that the 5.8ppm and 5.2ppm in the NMR spectrum (A) correspond to the characteristic peaks of vinyl. In the infrared spectrum B, 3078cm -1 and 995cm -1 They correspond to the CH stretching vibration peak of the vinyl group and the out-of-plane bending vibration of the C=C double bond, respectively.

[0043] Example 2

[0044] Polyethylene glycol monomethyl ether 4000 (4.0 g, 1 mmol) and tri(dibenzylideneacetone)dipalladium(0)-chloroform adduct (62.1 mg, 0.06 mmol), 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) and solvent dichloromethane 8 mL were added, and the reaction was controlled at 10°C and stirred for 6 hours. After the reaction was completed, the catalyst and phosphine ligand were removed to obtain polyethylene glycol-poly(2-vinyl)ethylene glycol copolymer with a yield of 80%, a number average molecular weight Mn: 5500, Mw / Mn: 1.06, and n,m≥1.

[0045] The reaction formula involved in this embodiment is as follows:

[0046]

[0047] Example 3

[0048] Polyethylene glycol 2000 (12.0 g, 6 mmol, Mn: 2500, Mw / Mn: 1.08), tris(dibenzylideneacetone)dipalladium(0)-chloroform adduct (373.6 mg, 0.15 mol% for VEC), and phosphine ligand bis(2-diphenylphosphinophenyl)ether (387.2 mg, 0.3 mol% for VEC) were added to the reactor, vacuum dehydrated, and replaced with N2 three times, and BEt3 (720 μL of 1 mol·L -1 in THF solution, 0.3 mol% for VEC) and 24 mL of dichloromethane solvent. After the polyethylene glycol is dissolved, 4-vinyl-1,3-dioxolane-2-one (27384.0 mg, 240 mmol, 40 eq.) is added, and the reaction is controlled at 10°C and stirred for 6 hours. After the reaction is completed, the catalyst and phosphine ligand are removed to obtain polyethylene glycol-poly (2-vinyl) ethylene glycol copolymer with a yield of 70%, a vinyl content of 6.14 ± 0.89 mmol / g, a number average molecular weight Mn: 4100, a polydispersity Mw / Mn: 1.07, and n1, n2 ≥ 1.

[0049] The reaction formula involved in this embodiment is as follows:

[0050]

[0051] The NMR spectrum of the polyethylene glycol-poly (2-vinyl) glycol copolymer prepared in this example is as follows Figure 2 shown.

[0052] Example 4

[0053] Polyethylene glycol 4000 (24.0 g, 6 mmol, Mn: 4900, Mw / Mn: 1.07), tris(dibenzylideneacetone)dipalladium(0)-chloroform adduct (373.6 mg, 0.15 mol% for VEC), and phosphine ligand bis(2-diphenylphosphinophenyl)ether (387.2 mg, 0.3 mol% for VEC) were added to the reactor, vacuum dehydrated, and replaced with N2 three times, and BEt3 (720 μL of 1 mol·L -1 in THF solution, 0.3mol% for VEC) and 48mL of solvent dichloromethane, after the polyethylene glycol is dissolved, 4-vinyl-1,3-dioxolane-2-one (27384.0mg, 240mmol, 40eq.) is added, and the reaction is controlled at 10°C and stirred for 6 hours. After the reaction is completed, the catalyst and phosphine ligand are removed to obtain polyethylene glycol-poly (2-vinyl) ethylene glycol copolymer with a yield of 78%, a vinyl content of 3.80±0.27mmol / g, a number average molecular weight Mn: 6800, a polydispersity Mw / Mn: 1.06, and n1, n2≥1.

[0054] The reaction formula involved in this embodiment is as follows:

[0055]

[0056] The NMR spectrum of the polyethylene glycol-poly (2-vinyl) glycol copolymer prepared in this example is as follows Figure 3 shown.

[0057] Example 5

[0058] Polyethylene glycol 6000 (36.0 g, 6 mmol, Mn: 8300, Mw / Mn: 1.03), tris(dibenzylideneacetone)dipalladium(0)-chloroform adduct (373.6 mg, 0.15 mol% for VEC), and phosphine ligand bis(2-diphenylphosphinophenyl)ether (387.2 mg, 0.3 mol% for VEC) were added to the reactor, vacuum dehydrated, and replaced with N2 three times, and BEt3 (720 μL of 1 mol·L -1in THF solution, 0.3mol% for VEC) and 72mL of dichloromethane solvent. After the polyethylene glycol is dissolved, 4-vinyl-1,3-dioxolane-2-one (27384.0mg, 240mmol, 40eq.) is added, and the reaction is controlled at 10°C and stirred for 6 hours. After the reaction is completed, the catalyst and phosphine ligand are removed to obtain polyethylene glycol-poly (2-vinyl) ethylene glycol copolymer with a yield of 87%, a vinyl content of 2.49±0.09mmol / g, a number average molecular weight Mn: 10100, a polydispersity Mw / Mn: 1.03, and n1, n2≥1.

[0059] The reaction formula involved in this embodiment is as follows:

[0060]

[0061] The NMR spectrum of the polyethylene glycol-poly (2-vinyl) glycol copolymer prepared in this example is as follows Figure 4 shown.

[0062] Example 6

[0063] Polyethylene glycol 8000 (48.0 g, 6 mmol, Mn: 10000, Mw / Mn: 1.04), tris(dibenzylideneacetone)dipalladium(0)-chloroform adduct (373.6 mg, 0.15 mol% for VEC), and phosphine ligand bis(2-diphenylphosphinophenyl)ether (387.2 mg, 0.3 mol% for VEC) were added to the reactor, vacuum dehydrated, and replaced with N2 three times, and BEt3 (720 μL of 1 mol·L -1 in THF solution, 0.3 mol% for VEC) and 96 mL of dichloromethane solvent. After the polyethylene glycol is dissolved, 4-vinyl-1,3-dioxolane-2-one (27384.0 mg, 240 mmol, 40 eq.) is added, and the reaction is controlled at 10°C and stirred for 6 hours. After the reaction is completed, the catalyst and phosphine ligand are removed to obtain polyethylene glycol-poly (2-vinyl) ethylene glycol copolymer with a yield of 87%, a vinyl content of 1.46 ± 0.07 mmol / g, a number average molecular weight Mn: 11300, a polydispersity Mw / Mn: 1.04, and n1, n2 ≥ 1.

[0064] The reaction formula involved in this embodiment is as follows:

[0065]

[0066] The NMR spectrum of the polyethylene glycol-poly (2-vinyl) glycol copolymer prepared in this example is as follows Figure 5 shown.

[0067] Example 7

[0068] Polyethylene glycol 10000 (60.0 g, 6 mmol, Mn: 12600, Mw / Mn: 1.06), tris(dibenzylideneacetone)dipalladium(0)-chloroform adduct (747.2 mg, 0.15 mol% for VEC), and phosphine ligand bis(2-diphenylphosphinophenyl)ether (774.4 mg, 0.3 mol% for VEC) were added into the reactor, vacuum dehydrated, and replaced with N2 three times, and BEt3 (1440 μL of 1 mol·L -1 in THF solution, 0.3mol% for VEC) and 120mL of dichloromethane solvent, after the polyethylene glycol is dissolved, 4-vinyl-1,3-dioxolane-2-one (54768.0mg, 480mmol, 80eq.) is added, and the reaction is controlled at 10°C and stirred for 12 hours. After the reaction is completed, the catalyst and phosphine ligand are removed to obtain polyethylene glycol-poly (2-vinyl) ethylene glycol copolymer with a yield of 85%, a vinyl content of 2.10±0.08mmol / g, a number average molecular weight Mn: 15400, a polydispersity Mw / Mn: 1.10, and n1, n2≥1.

[0069] The reaction formula involved in this embodiment is as follows:

[0070]

[0071] Example 8

[0072] Polyethylene glycol 20000 (60.0 g, 3 mmol, Mn: 22600, Mw / Mn: 1.10) and tris(dibenzylideneacetone)dipalladium(0)-chloroform adduct (186.8 mg, 0.15 mol% for VEC), phosphine ligand bis(2-diphenylphosphinophenyl)ether (193.6 mg, 0.3 mol% for VEC) were added into the reactor, vacuum dehydrated, and replaced with N2 three times, and BEt3 (360 μL of 1 mol·L -1 in THF solution, 0.3mol% for VEC) and 120mL of dichloromethane solvent, after the polyethylene glycol is dissolved, 4-vinyl-1,3-dioxolane-2-one (13692.0mg, 120mmol, 40eq.) is added, and the reaction is controlled at 10°C and stirred for 6 hours. After the reaction is completed, the catalyst and phosphine ligand are removed to obtain polyethylene glycol-poly (2-vinyl) ethylene glycol copolymer with a yield of 88%, a vinyl content of 0.33±0.05mmol / g, a number average molecular weight Mn: 23300, a polydispersity Mw / Mn: 1.10, and n1, n2≥1.

[0073] The reaction formula involved in this embodiment is as follows:

[0074]

[0075] Example 9

[0076] Polyethylene glycol 20000 (60.0 g, 3 mmol, Mn: 22600, Mw / Mn: 1.10) and tris(dibenzylideneacetone)dipalladium(0)-chloroform adduct (747.2 mg, 0.15 mol% for VEC) and phosphine ligand bis(2-diphenylphosphinophenyl)ether (774.4 mg, 0.3 mol% for VEC) were added into the reactor, vacuum dehydrated, and replaced with N2 three times, and BEt3 (1440 μL of 1 mol·L -1 in THF solution, 0.3mol% for VEC) and 120mL of dichloromethane solvent, after the polyethylene glycol is dissolved, 4-vinyl-1,3-dioxolane-2-one (54768.0mg, 480mmol, 160eq.) is added, and the reaction is controlled at 10°C and stirred for 12 hours. After the reaction is completed, the catalyst and phosphine ligand are removed to obtain polyethylene glycol-poly (2-vinyl) ethylene glycol copolymer with a yield of 72%, a vinyl content of 0.89±0.03mmol / g, a number average molecular weight Mn: 24000, a polydispersity Mw / Mn: 1.10, and n1, n2≥1.

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

[0078]

[0079] Example 10

[0080] Polyethylene glycol 10000 (60.0 g, 6 mmol, Mn: 12600, Mw / Mn: 1.06), tris(dibenzylideneacetone)dipalladium(0)-chloroform adduct (46.7 mg, 0.15 mol% for VEC), and phosphine ligand bis(2-diphenylphosphinophenyl)ether (48.4 mg, 0.3 mol% for VEC) were added into the reactor, vacuum dehydrated, and replaced with N2 three times, and BEt3 (90 μL of 1 mol·L -1in THF solution, 0.3 mol% for VEC) and 120 mL of dichloromethane solvent, after the polyethylene glycol is dissolved, 4-vinyl-1,3-dioxolane-2-one (3423.0 mg, 30 mmol, 5 eq.) is added, and the reaction is controlled at 10°C and stirred for 6 hours. After the reaction is completed, the catalyst and phosphine ligand are removed to obtain polyethylene glycol-poly (2-vinyl) ethylene glycol copolymer with a yield of 92%, a vinyl content of 0.23 ± 0.02 mmol / g, a number average molecular weight Mn: 12800, a polydispersity Mw / Mn: 1.06, and n1, n2 ≥ 1.

[0081] The reaction formula involved in this embodiment is as follows:

[0082]

[0083] Embodiment 11

[0084] Polyethylene glycol 10000 (60.0 g, 6 mmol, Mn: 12600, Mw / Mn: 1.06), tris(dibenzylideneacetone)dipalladium(0)-chloroform adduct (93.4 mg, 0.15 mol% for VEC), and phosphine ligand bis(2-diphenylphosphinophenyl)ether (96.8 mg, 0.3 mol% for VEC) were added into the reactor, vacuum dehydrated, and replaced with N2 three times, and BEt3 (180 μL of 1 mol·L -1 in THF solution, 0.3mol% for VEC) and 120mL of dichloromethane solvent, after the polyethylene glycol is dissolved, 4-vinyl-1,3-dioxolane-2-one (6846.0mg, 60mmol, 10eq.) is added, and the reaction is controlled at 10°C and stirred for 6 hours. After the reaction is completed, the catalyst and phosphine ligand are removed to obtain polyethylene glycol-poly (2-vinyl) ethylene glycol copolymer with a yield of 93%, a vinyl content of 0.46±0.04mmol / g, a number average molecular weight Mn: 12900, a polydispersity Mw / Mn: 1.07, and n1, n2≥1.

[0085] The reaction formula involved in this embodiment is as follows:

[0086]

[0087] Example 12

[0088] Polyethylene glycol 10000 (60.0 g, 6 mmol, Mn: 12600, Mw / Mn: 1.06), tris(dibenzylideneacetone)dipalladium(0)-chloroform adduct (186.8 mg, 0.15 mol% for VEC), and phosphine ligand bis(2-diphenylphosphinophenyl)ether (193.6 mg, 0.3 mol% for VEC) were added into the reactor, vacuum dehydrated, and replaced with N2 three times, and BEt3 (360 μL of 1 mol·L -1 in THF solution, 0.3 mol% for VEC) and 120 mL of dichloromethane solvent, after the polyethylene glycol is dissolved, 4-vinyl-1,3-dioxolane-2-one (13692.0 mg, 120 mmol, 20 eq.) is added, and the reaction is controlled at 10°C and stirred for 6 hours. After the reaction is completed, the catalyst and phosphine ligand are removed to obtain polyethylene glycol-poly (2-vinyl) ethylene glycol copolymer with a yield of 85%, a vinyl content of 0.63 ± 0.03 mmol / g, a number average molecular weight Mn: 13800, a polydispersity Mw / Mn: 1.07, and n1, n2 ≥ 1.

[0089] The reaction formula involved in this embodiment is as follows:

[0090]

[0091] Embodiment 13

[0092] Polyethylene glycol 6000 (36.0 g, 6 mmol, Mn: 8300, Mw / Mn: 1.03), tris(dibenzylideneacetone)dipalladium(0)-chloroform adduct (46.7 mg, 0.15 mol% for VEC), and phosphine ligand bis(2-diphenylphosphinophenyl)ether (48.4 mg, 0.3 mol% for VEC) were added into the reactor, vacuum dehydrated, and replaced with N2 three times, and BEt3 (90 μL of 1 mol·L -1 in THF solution, 0.3mol% for VEC) and 72mL of dichloromethane solvent. After the polyethylene glycol is dissolved, 4-vinyl-1,3-dioxolane-2-one (3423.0mg, 30mmol, 5eq.) is added, and the reaction is controlled at 10°C and stirred for 6 hours. After the reaction is completed, the catalyst and phosphine ligand are removed to obtain polyethylene glycol-poly (2-vinyl) glycol copolymer with a yield of 96%, a vinyl content of 0.43±0.04mmol / g, a number average molecular weight Mn: 8500, a polydispersity Mw / Mn: 1.03, and n1, n2≥1.

[0093] The reaction formula involved in this embodiment is as follows:

[0094]

[0095] Embodiment 14

[0096] Polyethylene glycol 4000 (24.0 g, 6 mmol, Mn: 4900, Mw / Mn: 1.07), tris(dibenzylideneacetone)dipalladium(0)-chloroform adduct (46.7 mg, 0.15 mol% for VEC), and phosphine ligand bis(2-diphenylphosphinophenyl)ether (48.4 mg, 0.3 mol% for VEC) were added into the reactor, vacuum dehydrated, and replaced with N2 three times, and BEt3 (90 μL of 1 mol·L -1 in THF solution, 0.3mol% for VEC) and 48mL of dichloromethane solvent, after the polyethylene glycol is dissolved, 4-vinyl-1,3-dioxolane-2-one (3423.0mg, 30mmol, 5eq.) is added, and the reaction is controlled at 10°C and stirred for 6 hours. After the reaction is completed, the catalyst and phosphine ligand are removed to obtain polyethylene glycol-poly (2-vinyl) ethylene glycol copolymer with a yield of 94%, a vinyl content of 0.73±0.06mmol / g, a number average molecular weight Mn: 5000, a polydispersity Mw / Mn: 1.07, and n1, n2≥1.

[0097] The reaction formula involved in this embodiment is as follows:

[0098]

[0099] Embodiment 15

[0100] Polyethylene glycol 8000 (48.0 g, 6 mmol, Mn: 10000, Mw / Mn: 1.04), tris(dibenzylideneacetone)dipalladium(0)-chloroform adduct (46.7 mg, 0.15 mol% for VEC), and phosphine ligand bis(2-diphenylphosphinophenyl)ether (48.4 mg, 0.3 mol% for VEC) were added into the reactor, vacuum dehydrated, and replaced with N2 three times, and BEt3 (90 μL of 1 mol·L -1in THF solution, 0.3mol% for VEC) and 96mL of dichloromethane solvent, after the polyethylene glycol is dissolved, 4-vinyl-1,3-dioxolane-2-one (3423.0mg, 30mmol, 5eq.) is added, and the reaction is controlled at 10°C and stirred for 6 hours. After the reaction is completed, the catalyst and phosphine ligand are removed to obtain polyethylene glycol-poly (2-vinyl) ethylene glycol copolymer with a yield of 96%, a vinyl content of 0.32±0.02mmol / g, a number average molecular weight Mn: 10100, a polydispersity Mw / Mn: 1.04, and n1, n2≥1.

[0101] The reaction formula involved in this embodiment is as follows:

[0102]

[0103] The NMR spectrum of the polyethylene glycol-poly (2-vinyl) glycol copolymer prepared in this example is as follows Figure 6 shown.

[0104] Application Example: Application of the Copolymer of the Present Invention to the Preparation of Phase Change Materials

[0105] The preparation method is as follows:

[0106] 94 parts of polyethylene glycol 8000-poly (2-vinyl) glycol copolymer prepared in Example 15, 4 parts of trimethylolpropane tris (3-mercaptopropionate) (TMPTMP), and 2 parts of Irgacure 1173 were taken by mass, and the raw materials of each component were melt-blended at 80° C. in a dark room away from light for 10 minutes. After mixing evenly, the mixture was poured into a mold and irradiated under a 365nm ultraviolet lamp for 5 minutes to obtain a phase change material PCM.

[0107] Performance Test:

[0108] The solid-solid phase change characteristics, phase change temperature, heat storage capacity, thermal stability and mechanical properties of the phase change material PCM are evaluated. The test method is as follows:

[0109] (1) Solid-solid phase change characteristics test:

[0110] After placing the material on a heating table set at 80°C / 120°C for one hour, observe whether the solid-solid phase change material leaks.

[0111] (2) Testing of phase change temperature and heat storage capacity:

[0112] The phase transition temperature and heat storage capacity of the polymer were tested by DSC2000 of TA in the United States. Weigh 5-10 mg of sample in an aluminum crucible, heat it from 40°C to 100°C at a heating rate of 20°C / min in a nitrogen atmosphere, and keep it warm for 3 minutes to eliminate the thermal history. Then cool it to 0°C at a cooling rate of 10°C / min and keep it warm for 2 minutes, and then heat it to 100°C at a heating rate of 10°C / min. Use TA University Analysis software to process the data to obtain the phase transition temperature of the polymer, as well as the latent heat, that is, the heat storage capacity.

[0113] (3) Thermal performance test:

[0114] Thermogravimetric analyzer (TG 209F3) was used in the range of 50-700°C with a heating rate of 20°C min -1 The thermal stability of the cured material in a nitrogen atmosphere was determined, and the temperature corresponding to the 5% mass degradation was taken as the initial decomposition temperature of the material (T 5％ ).

[0115] (4) Tensile test:

[0116] The material was tensile tested using an Instron 3365 electronic universal material testing machine at a speed of 50 mm / min, and the accurate values ​​of modulus, tensile strength at break and elongation at break were obtained using the average value of five experiments.

[0117] After testing, the phase change temperature (T m ) is 52.1℃, latent heat is 98.9J / g, no leakage at 80℃ and 120℃, initial decomposition temperature T 5％ The temperature is 354.1℃, the Young's modulus is 88.2MPa, the tensile strength at break is 12.4MPa, and the elongation at break is 52%. The prepared phase change material has excellent solid-solid phase change characteristics, heat storage capacity, thermal stability and mechanical properties.

Claims

1. A polyethylene glycol-poly (2-vinyl) glycol copolymer, the structure of which is selected from any one of the following structural formulas: Where: 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 one of the sulfur hetero chains; m, n, n1 and n2 are all positive integers, and m, n, n1 and n2 ≥ 1.

2. A polyethylene glycol-poly (2-vinyl) glycol copolymer according to claim 1, characterized in that: The polyethylene glycol-poly (2-vinyl) glycol copolymer has a number average molecular weight of 500 to 30,000, a double bond content of 0.33 mmol / g to 6.14 mmol / g, and a polydispersity PDI of 1.03 to 1.

08.

3. A method for preparing a polyethylene glycol-poly (2-vinyl) glycol copolymer, characterized in that: The method comprises the following steps: using polyethylene glycol containing 1 or 2 hydroxyl groups and 4-vinyl-1,3-dioxolane-2-one or vinyl oxirane as raw materials, dissolving them in an organic solvent, and reacting them in the presence of a palladium catalyst and a phosphine ligand to obtain a polyethylene glycol-poly (2-vinyl) glycol copolymer.

4. The method for preparing a polyethylene glycol-poly (2-vinyl) glycol copolymer according to claim 3, characterized in that: The polyethylene glycol is selected from any one of polyethylene glycols with a molecular weight of 400 to 25,000.

5. The method for preparing a polyethylene glycol-poly (2-vinyl) glycol copolymer 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.

6. The method for preparing a polyethylene glycol-poly (2-vinyl) glycol copolymer 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.

7. The method for preparing a polyethylene glycol-poly (2-vinyl) glycol copolymer 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.

8. The method for preparing a polyethylene glycol-poly (2-vinyl) glycol copolymer according to claim 7, characterized in that: The solvent is selected from tetrahydrofuran and diethyl ether.

9. The method for preparing a polyethylene glycol-poly (2-vinyl) glycol copolymer according to claim 3, characterized in that: The reaction temperature is 10-70°C.

10. The method for preparing a polyethylene glycol-poly (2-vinyl) glycol copolymer according to claim 3, characterized in that: The reaction time is 1-8 hours.

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