Tetrahydrofurfuryl acrylate-ethylene binary copolymer and preparation method thereof

Abstract

The invention relates to the field of macromolecules, in particular to a tetrahydrofurfuryl acrylate-ethylene binary copolymer and a preparation method thereof. In the preparation method, a nonmetal Lewis acid complex catalyst is adopted to catalyze ethylene and tetrahydrofurfuryl acrylate to be copolymerized under mild conditions of low temperature and low pressure to form a biopolymer. According to the preparation method disclosed by the invention, the catalyst and the initiator are matched with each other, so that the finally obtained binary copolymer has an ethylene insertion rate of not less than 30%, the ethylene insertion rate is high, the chain flexibility of the binary copolymer can be increased, and the binary copolymer has a relatively low glass-transition temperature of-20 DEG C or below. And the conversion rate of the tetrahydrofurfuryl acrylate can reach more than 80%.

Description

Technical Field

[0001] The present invention relates to the field of polymers, and particularly to a tetrahydrofurfuryl acrylate-ethylene binary copolymer and a preparation method thereof. Background Art

[0002] With the rapid increase of environmental problems and the concern for the sustainability of the ecological environment, the demand for the resource utilization and functionalization of biomass raw materials is also increasing day by day. Due to the inherent structural diversity and chemical heterogeneity of biomass, compared with their petroleum-based counterparts, most biomass products have poor performance and high costs. Moreover, it is usually necessary to carefully adjust chemical composition, molecular weight, chain entanglement, topological structure, microphase separation morphology and network structure to develop biomass-based polymer materials with specific structures and properties.

[0003] Tetrahydrofurfuryl acrylate (THFA) is an acrylate monomer with a furan ring side group. THFA has shown good application potential in the fields of photocuring, 3D printing and the construction of elastomers. It can be converted from inexpensive biomass materials such as cellulose, hemicellulose and lignin. Although its homopolymer (PTHFA) has a glass transition temperature below -20°C, due to the steric hindrance of the lateral furan ring and intermolecular interactions, it is difficult for PTHFA above the glass transition temperature at room temperature to improve its mechanical strength through crystallization. Improving and regulating the chain structure, especially the sequence structure, of PTHFA is a common method to solve the above problems. If it is necessary to maintain the flexible chain characteristics of PTHFA itself, copolymerization with non-polar ethylene (E) without side groups is a good choice.

[0004] There are generally three methods for copolymerizing non-polar monomers such as ethylene with polar olefin monomers such as THFA: (1) free radical polymerization under high temperature and high pressure; (2) coordination polymerization of transition metal-complexes; (3) Lewis acid catalysis.

[0005] First is free radical polymerization under high temperature and high pressure: copolymerizing ethylene with polar monomers by means of harsh polymerization, such as ethylene-acrylonitrile. Compared with polymerization under mild conditions, this method can obtain ethylene chain segments with a higher insertion rate. However, the insertion rate of polar monomers is low and it is difficult to control the sequence structure, with high energy consumption and high requirements for equipment.

[0006] Second is coordination polymerization catalyzed by transition metals: This method enables polar monomers to copolymerize with ethylene under relatively mild conditions. Generally, transition metal catalysis can well regulate the sequence structure of copolymers by regulating ligands, etc. However, due to the poisoning effect of the polar groups of polar monomers on the transition metal center, this will hinder the further insertion of monomers. Therefore, this polymerization method often results in a low insertion rate of polar monomers in the binary copolymer.

[0007] Finally, there is Lewis acid-catalyzed radical polymerization: Radical polymerization under Lewis acid catalysis is also called complex polymerization. In this method, after a Lewis acid coordinates with the polar group of a polar monomer, the electron cloud density difference between the polar monomer and the C=C double bond of ethylene is further increased, and it grows into a binary copolymer under the initiation of a radical polymerization initiator. Complex polymerization can obtain copolymers with a wide range of changes in the insertion rate of polar monomers, and the polymerization conditions are relatively mild. However, there are also technical problems such as long reaction time and large catalyst dosage. Summary of the Invention

[0008] The object of the present invention is to overcome the technical defects in the prior art that the reactivity ratios of ethylene and THFA are quite different, and the products obtained by polymerization have low conversion rate, low molecular weight, and low insertion rate of ethylene.

[0009] Provide a tetrahydrofurfuryl acrylate-ethylene binary copolymer and a preparation method thereof.

[0010] In a first aspect, the present invention provides a method for preparing a tetrahydrofurfuryl acrylate-ethylene binary copolymer, comprising the following steps:

[0011] Step 1: Pre-complex a catalyst with a tetrahydrofurfuryl acrylate polar monomer under an inert gas atmosphere to form a mixed solution E; the catalyst is at least one of BF3·THF and BF3·OEt2;

[0012] Step 2: Add the mixed solution E to a high-pressure reactor for copolymerization reaction to obtain a polymer, the pressure range of the copolymerization reaction is 1-10 MPa, and the temperature of the copolymerization reaction is 40-60 °C.

[0013] In the method of the present invention, a non-metallic Lewis acid complex catalyst is used to catalyze the copolymerization of ethylene and tetrahydrofurfuryl acrylate to form a binary copolymer under mild conditions of low temperature (40-60 °C) and low pressure (1-10 MPa). By selecting the mutual cooperation between the catalyst and the initiator in the preparation method of the present invention, the finally obtained binary copolymer has an ethylene insertion rate of not less than 30%. The high ethylene insertion rate can increase the flexibility of the binary copolymer chain and further reduce the glass transition temperature of the binary copolymer. In the preparation method of the present invention, the conversion rate of tetrahydrofurfuryl acrylate can reach more than 80%.

[0014] For a polymer chain that grows by a radical mechanism, the greater the difference in the electron cloud density of the two monomers, the more conducive it is to the generation of an alternating sequence structure. Based on this characteristic, the inventor uses Lewis acid coordination to further increase the electron cloud density of the C=C double bonds of the two types of monomers.

[0015] Commonly used metal salt Lewis acids such as trifluoromethanesulfonates often remain in the copolymer, damaging various properties of the copolymer including thermal properties, and need to be washed multiple times to remove.

[0016] Non-metal Lewis acids avoid the toxicity of metal catalysts and the characteristics of being sensitive to oxygen and moisture, and the Lewis acids with non-metal centers added in the form of complexes are very suitable for the coordination copolymerization of biomass monomers with furan rings while avoiding the above problems.

[0017] Lewis acid-catalyzed binary copolymerization of E-THFA can make E insert relatively uniformly into the structural units of PTHFA, and greatly improve the polymer chain structure, especially the sequence structure, under mild conditions.

[0018] Non-metal Lewis acids have the characteristics of avoiding the toxicity of metal catalysts and being sensitive to oxygen and moisture. Therefore, the present invention uses non-metal Lewis acids for catalysis to polymerize E-THFA binary copolymers under relatively mild conditions.

[0019] Preferably, in step 1, the pre-complexation specifically includes:

[0020] Step 1.1: Dissolve the tetrahydrofurfuryl acrylate monomer to obtain solution A; dissolve the initiator to obtain solution B, and store it for standby at 2-8°C; the initiator is at least one of azo initiators and peroxide initiators;

[0021] Preferably, in the pre-complexation reaction, the solvent used for dissolution is at least one of tetrahydrofuran, toluene, dichloromethane, N-methylpyrrolidone, dimethyl sulfoxide, N,N-dimethylformamide, 1,4-dioxane, dichloromethane, and chloroform.

[0022] More preferably, in step 1.1, the mass ratio of the tetrahydrofurfuryl acrylate monomer to the solvent is 8-10:40-50;

[0023] In step 1.1, the mass ratio of the initiator to the solvent is 0-0.06:0-20; preferably, the amounts of the initiator and the solvent do not include the endpoint value 0.

[0024] Step 1.2: Add BF3·THF complex and / or BF3·OEt2 complex to solution A in step 1.1, stir until the solution turns light orange to obtain solution C, mix solution C with solution B in step 1.1 to obtain solution D, and add a solvent to solution D to a predetermined polymerization amount to obtain a mixed solution E.

[0025] Preferably, in step 1.2, the stirring rate is 50-1000 r / min;

[0026] Preferably, in step 1.2, the mass ratio of solution D to the solvent is 50-60:50-40.

[0027] Preferably, the inert gas atmosphere is a nitrogen atmosphere.

[0028] Preferably, the azo initiator includes azobisisobutyronitrile, azobisisoheptonitrile, azodimethoxyisoheptonitrile, azobisisovaleronitrile, dimethyl azobisisobutyrate;

[0029] The peroxide initiator includes benzoyl peroxide, tert-butyl benzoyl peroxide, methyl ethyl ketone peroxide, diisopropylbenzene peroxide, di-tert-butyl peroxide.

[0030] More preferably, the amount of the initiator is 0.05 mol - 5 mol% of the tetrahydrofurfuryl acrylate monomer.

[0031] Preferably, the amount of the catalyst is 10 - 100 mol% of the tetrahydrofurfuryl acrylate monomer.

[0032] Preferably, in step 2, the copolymerization reaction specifically includes:

[0033] Set the gas pressure range of the ethylene high-pressure reactor to 1 - 10 MPa, set the reaction time and stirring rate, react for 1 - 12 h, precipitate the reaction solution, and obtain the ethylene-tetrahydrofurfuryl acrylate binary copolymer after concentration and drying.

[0034] Step 2.1: Pour the mixed solution E into the reaction kettle of the ethylene high-pressure reactor and tighten the nut for sealing. Put the heating jacket on the reaction kettle, open the valve of the ethylene gas cylinder, first adjust the pressure reducing valve to 0.5 MPa, sequentially open the ball valve and needle valve leading to the reaction kettle, and slowly open the inlet valve on the reaction kettle to introduce 0.5 MPa of ethylene gas into the reaction kettle.

[0035] Step 2.2: After flushing the reaction pipeline 3 times with 0.5 MPa of ethylene gas, keep the ethylene inlet valve on the reaction kettle open and the outlet valve closed, slowly adjust the pressure reducing valve in front to increase the pressure of ethylene gas in the reaction kettle to 1 - 10 MPa, and then close the ethylene inlet valve.

[0036] Step 2.3: Set the reaction temperature at 40 - 60 °C and the stirring speed at 50 - 400 r / min, start heating and stirring, and record the time when the predetermined temperature, speed, and ethylene pressure are reached as the start time of the polymerization reaction.

[0037] After the reaction time of 1 - 12 h, pour the reaction solution into 400 - 500 mL of a precipitant for precipitation, concentrate, filter by suction, and place it in a vacuum drying oven at 40 - 70 °C for vacuum drying for 12 - 48 h to obtain the ethylene-tetrahydrofurfuryl acrylate binary copolymer.

[0038] Preferably, the pressure of ethylene in the reaction kettle is 4-10 MPa.

[0039] Preferably, the polymerization reaction time is 6-12 h.

[0040] In the second aspect, the acrylic tetrahydrofurfuryl ester-ethylene binary copolymer obtained according to the above preparation method has the chemical structure:

[0041]

[0042] Among them, m represents the number of repeating structural units of acrylic tetrahydrofurfuryl ester (THFA), and n represents the number of repeating structural units of ethylene;

[0043] In the binary copolymer, the proportion range of the alternating sequence structure is 20 mol%-30 mol%;

[0044] The weight-average molecular weight range of the binary copolymer is 10,000-20,000;

[0045] In the binary copolymer, the ethylene insertion rate range is not less than 30 mol%.

[0046] In the acrylic tetrahydrofurfuryl ester-ethylene binary copolymer obtained by the preparation method of the present invention, the monomer conversion rate of the acrylic tetrahydrofurfuryl ester (THFA) is not less than 80%; among them, the ethylene insertion rate is 30 mol%-45 mol%. The glass transition temperature is further reduced to less than -20 °C.

[0047] Compared with the prior art, the beneficial effects of the present invention:

[0048] In the method of the present invention, a non-metallic Lewis acid complex catalyst is used to catalyze the copolymerization of ethylene and acrylic tetrahydrofurfuryl ester to form a binary copolymer under mild conditions of low temperature (40-60 °C) and low pressure (1-10 MPa). By selecting the mutual cooperation between the catalyst and the initiator in the preparation method of the present invention, the finally obtained binary copolymer has an ethylene insertion rate of not less than 30%, and the high ethylene insertion rate can increase the flexibility of the binary copolymer chain, making the binary copolymer have a low glass transition temperature (below -20 °C). In the preparation method of the present invention, the conversion rate of acrylic tetrahydrofurfuryl ester can reach more than 80%. Description of the Drawings

[0049] Figure 1 The molecular weight and its distribution diagram of polymer #1 obtained by the preparation method of Example 1.

[0050] Figure 2 The nuclear magnetic resonance hydrogen spectrum of polymer #1 obtained by the preparation method of Example 1.

[0051] Figure 3 The molecular weight and its distribution diagram of the homopolymer obtained by the preparation method of Comparative Example 3.

[0052] Figure 4 1H NMR spectrum of the homopolymer obtained by the preparation method of Comparative Example 3.

[0053] Figure 5 13C NMR spectrum of the E-THFA copolymer of Example 1.

[0054] Figure 6 Enlarged view of the peak position of carbon No. 3 in the 13C NMR spectrum of the E-THFA copolymer of Example 1.

[0055] Figure 7 Schematic diagram for comparison of 13C NMR spectra of three different halo-boron catalyzed copolymers obtained by the preparation methods corresponding to Example 1 and Comparative Examples 2-3;

[0056] Figure 8 DSC curve of the E-THFA copolymer of Example 1. Detailed Description of the Specific Embodiments

[0057] The present invention will be further described in detail below in conjunction with specific embodiments. However, it should not be understood that the scope of the above subject matter of the present invention is limited to the following embodiments. All technologies implemented based on the content of the present invention belong to the scope of the present invention.

[0058] Example 1

[0059] A preparation method of a binary copolymer of tetrahydrofurfuryl acrylate and ethylene,

[0060] Step 1.1: 8.132 mL (0.056 mol) of tetrahydrofurfuryl acrylate, 6.113 mL (0.056 mol) of BF3·THF, 0.055 g of azodiisobutyronitrile, 100 mL of tetrahydrofuran. The above content of tetrahydrofurfuryl acrylate is dissolved in tetrahydrofuran solvent to obtain solution A, and azodiisobutyronitrile is dissolved in tetrahydrofuran solvent to obtain solution B, and stored at 2-8 °C for later use;

[0061] Step 1.2: Add BF3·THF to solution A, stir until the solution turns light orange to obtain solution C, mix solution C with solution B to obtain solution D, and add solvent to solution D to a predetermined amount for polymerization to obtain mixed solution E.

[0062] Add the above-mentioned mixed solution E into the reaction kettle of the high-pressure ethylene reactor. After flushing the reaction pipeline with ethylene gas three times, close the outlet valve, and react with 4 MPa of ethylene in the high-pressure ethylene reactor at 50 °C for 8 h to obtain a polymer solution. Concentrate it by rotary evaporation at 50 °C, then pour the solution into water to obtain a polymer precipitate. Let it stand for 24 h, filter off the supernatant, and dry it under vacuum at 50 °C and -0.1 MPa to obtain copolymer #1.

[0063] Copolymer #1 was dissolved in tetrahydrofuran (THF), and the molecular weight and distribution of the polymer were characterized by gel permeation chromatography (GPC). The results are as Figure 1 shown; the polymer was dissolved in deuterated chloroform for nuclear magnetic resonance hydrogen spectrum characterization of the copolymer structure, as Figure 2 shown.

[0064] Example 2

[0065] This example provides a method for preparing a binary copolymer of tetrahydrofurfuryl acrylate and ethylene. The preparation method is the same as that of Example 1, except that the catalyst is selected as BF3·OEt2.

[0066] Example 3

[0067] This example provides a method for preparing a binary copolymer of tetrahydrofurfuryl acrylate and ethylene. The preparation method is the same as that of Example 1, except that the catalyst dosage is 10 mol%.

[0068] Example 4

[0069] This example provides a method for preparing a binary copolymer of tetrahydrofurfuryl acrylate and ethylene. The preparation method is the same as that of Example 2, except that the catalyst dosage is 30 mol%.

[0070] Example 5

[0071] This example provides a method for preparing a binary copolymer of tetrahydrofurfuryl acrylate and ethylene. The preparation method is the same as that of Example 1, except that the catalyst dosage is 50 mol%.

[0072] Example 6

[0073] This example provides a method for preparing a binary copolymer of tetrahydrofurfuryl acrylate and ethylene. The preparation method is the same as that of Example 2, except that the catalyst dosage is 70 mol%.

[0074] Example 7

[0075] This example provides a method for preparing a binary copolymer of tetrahydrofurfuryl acrylate and ethylene. The preparation method is the same as that of Example 1, except that the catalyst dosage is 90 mol%.

[0076] Example 8

[0077] This example provides a preparation method of a binary copolymer of tetrahydrofurfuryl acrylate and ethylene. The preparation method is the same as that of Example 1, except that the dosage of the initiator is 0.05 mol%.

[0078] Example 9

[0079] This example provides a preparation method of a binary copolymer of tetrahydrofurfuryl acrylate and ethylene. The preparation method is the same as that of Example 1, except that the polymerization temperature is 60 °C.

[0080] Example 10

[0081] This example provides a preparation method of a binary copolymer of tetrahydrofurfuryl acrylate and ethylene. The preparation method is the same as that of Example 1, except that the initiator is BPO and the polymerization temperature is 100 °C.

[0082] Example 11

[0083] This example provides a preparation method of a binary copolymer of tetrahydrofurfuryl acrylate and ethylene. The preparation method is the same as that of Example 1, except that the initiator is DMPPA and the polymerization temperature is 65 °C.

[0084] Example 12

[0085] This example provides a preparation method of a binary copolymer of tetrahydrofurfuryl acrylate and ethylene. The preparation method is the same as that of Example 1, except that the initiator is AIBME and the polymerization temperature is 66 °C.

[0086] Example 13

[0087] This example provides a preparation method of a binary copolymer of tetrahydrofurfuryl acrylate and ethylene. The preparation method is the same as that of Example 1, except that the initiator is AMBN and the polymerization temperature is 67 °C.

[0088] Comparative Example 1

[0089] This example provides a preparation method of a binary copolymer of tetrahydrofurfuryl acrylate and ethylene. The preparation method is the same as that of Example 1, except that the catalyst is B(Et)3.

[0090] Comparative Example 2

[0091] This example provides a preparation method of a binary copolymer of tetrahydrofurfuryl acrylate and ethylene. The preparation method is the same as that of Example 1, except that the catalyst is BCl3·CH2Cl2.

[0092] Comparative Example 3

[0093] This example provides a method for preparing a binary copolymer of tetrahydrofurfuryl acrylate and ethylene. The preparation method is the same as that of Example 1, except that the catalyst is selected as BBr3·CH2Cl2.

[0094] Comparative Example 4

[0095] This example provides a method for preparing a binary copolymer of tetrahydrofurfuryl acrylate and ethylene. The preparation method is the same as that of Example 1, except that no catalyst is used.

[0096] Comparative Example 5

[0097] This example provides a method for preparing a binary copolymer of tetrahydrofurfuryl acrylate and ethylene. The difference from Example 1 is that no catalyst and initiator are set.

[0098] Comparative Example 6

[0099] This example provides a method for preparing a binary copolymer of tetrahydrofurfuryl acrylate and ethylene. The difference from Example 1 is that no initiator is set.

[0100] Comparative Example 7

[0101] This example provides a method for preparing a binary copolymer of tetrahydrofurfuryl acrylate and ethylene. The difference from Example 1 is that the polymerization reaction is carried out at atmospheric pressure.

[0102] Specifically, the experimental parameters and structure test data in the above Examples 1-13 and Comparative Examples 1-7 are summarized in Tables 1-3.

[0103] Table 1 is a summary table of the parameter information and performance data of Examples 8-13 and Comparative Examples 5-7

[0104]

[0105] Note: The dosages of the catalyst and the initiator are calculated respectively according to the dosage of the tetrahydrofurfuryl acrylate monomer

[0106] Table 2 is a summary table of the parameter information and performance data of Examples 1-2 and Comparative Examples 1-3

[0107]

[0108] Note: The dosages of the catalyst and the initiator are calculated respectively according to the dosage of the tetrahydrofurfuryl acrylate monomer

[0109] Table 3 is a summary table of the parameter information and performance data of Examples 3-7 and Comparative Example 3

[0110]

[0111] Note: The dosages of the catalyst and the initiator are calculated according to the dosage of the tetrahydrofurfuryl acrylate monomer respectively.

[0112] Among them, the weight-average molecular weight and the ethylene insertion rate of the polymerization products in Examples 1-13 and Comparative Examples 1-7 were obtained by calculating with 13C NMR spectroscopy.

[0113] As can be seen from Examples 1-2 and Comparative Examples 1-3 in Table 2, in the same tetrahydrofuran (THF) solvent, different Lewis acids as catalysts have significant differences in the catalytic copolymerization effect of tetrahydrofurfuryl acrylate (THFA) and ethylene. When two BF3 complexes are used as catalysts, both have a relatively high conversion rate of tetrahydrofurfuryl acrylate. While when alkyl boron and two more Lewis acidic halo borons are used as catalysts, the conversion rate is relatively low.

[0114] In Comparative Examples 2-3, the catalytic copolymerization effect of the two halo borons on THFA and ethylene is very limited, and it is difficult to obtain more copolymers. What is obtained is likely to be a mixture of a small amount of copolymers and homopolymers. This is the reason why the molecular weight of the polymer obtained by BCl3 catalysis is significantly higher than that of BF3. Therefore, the molecular weight distribution of Comparative Example 2 also shows the characteristic of bimodal distribution, and there is no characteristic peak of the No. 3 carbon at 40-45 ppm in its 13C NMR spectrum, as Figure 7 shown. From top to bottom are the 13C NMR spectra of the halo boron-catalyzed copolymers obtained by using BF3, BCl3, and BBr3 catalysts respectively.

[0115] As can be seen from the parameter information of Comparative Example 3 in Table 3, in the case of not adding a Lewis acid catalyst, only homopolymers can be catalytically obtained, as Figure 2 and Figure 4 , Figure 2 is the 1H NMR spectrum of the copolymer prepared in Example 1; Figure 4 is the 1H NMR spectrum of the THFA homopolymer prepared in Comparative Example 3. According to Figure 2 , Figure 4 's 1H NMR spectra, there is an extra peak of the H of the ethylene -CH2 around 1.2 position in the copolymer. Figure 2 The unimodal distribution of the GPC of the E-THFA copolymer in

[0116] also indicates that this is not a mixture of homopolymers of the two monomers, fully proving the success of the copolymerization. Figure 5 As shown in Figure 5 is the 13C NMR spectrum of the E-THFA copolymer of Example 1. The peak at around 40-45 ppm is the peak of the C connected to the carbonyl group on the main chain. At this position, it is divided into three peaks, which respectively represent three sequence structures in the polymer main chain. Further, expanding Figure 6 the carbon spectrum ofFigure 6 It can be seen that from low field to high field are the alternating sequence (EME), the THFA-rich sequence (MME), and the THFA homopolymer sequence (MMM) respectively. From Figure 6 the distribution of the carbon spectral peaks, it can be known that the proportion of the THFA homopolymer sequence in the copolymer chain is not very high. The possible reason is that some THFA has undergone free radical homopolymerization before reaching the predetermined polymerization temperature and ethylene gas pressure.

[0117] Such as Figure 1 shown is the molecular weight distribution curve of the copolymer of Example 1, Figure 3 and is the molecular weight distribution curve of the homopolymer of Comparative Example 3. Such as Figure 8 shown is the DSC curve of the copolymer of Example 1.

[0118] In the technical solution of the present invention, a non-metallic Lewis acid complex catalyst is used to catalyze the copolymerization of ethylene and tetrahydrofurfuryl acrylate to form a binary copolymer under mild conditions of low temperature and low pressure. By selecting the mutual cooperation between the catalyst and the initiator in the preparation method of the present invention, the finally obtained binary copolymer has an ethylene insertion rate of not less than 30%. The high ethylene insertion rate can increase the flexibility of the binary copolymer chain, making the binary copolymer have a lower glass transition temperature; and the conversion rate of tetrahydrofurfuryl acrylate can reach more than 80%.

[0119] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent replacements, and improvements made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A preparation method of a tetrahydrofurfuryl acrylate-ethylene binary copolymer, characterized in that, It includes the following steps: Step 1: Pre-complex the catalyst with the tetrahydrofurfuryl acrylate polar monomer in an inert gas atmosphere to form a mixed solution E; the catalyst is at least one of BF3·THF and BF3·OEt2; Step 2: Add the mixed solution E into an ethylene high-pressure reactor for copolymerization reaction to obtain a polymer. The pressure range of the copolymerization reaction is 1-10 MPa, and the temperature of the copolymerization reaction is 40-60 °C.

2. The preparation method according to claim 1, characterized in that, In Step 1, the specific steps of the pre-complexation are: Step 1.1: Dissolve the tetrahydrofurfuryl acrylate polar monomer to obtain solution A; dissolve the initiator to obtain solution B and store it for standby at 2-8 °C; the initiator is at least one of azo initiators and peroxide initiators; Step 1.2: Add the BF3·THF and / or BF3·OEt2 complex into solution A in Step 1.1, stir until the solution turns light orange to obtain solution C, mix solution C with solution B to obtain solution D, and add a solvent to solution D to a predetermined amount for polymerization to obtain a mixed solution E.

3. The preparation method according to claim 2, wherein, The azo initiators include azobisisobutyronitrile, azobisisoheptonitrile, azodimethoxyisoheptonitrile, azobisisovaleronitrile, and dimethyl azodicarboxylate; The peroxide initiators include benzoyl peroxide, tert-butyl peroxybenzoate, methyl ethyl ketone peroxide, diisopropylbenzene peroxide, and di-tert-butyl peroxide.

4. The preparation method according to claim 2, characterized in that, The dosage of the initiator is 0.05 mol - 5 mol% of the tetrahydrofurfuryl acrylate monomer.

5. The preparation method according to claim 2, characterized in that The dosage of the catalyst is 10 mol - 100 mol% of the tetrahydrofurfuryl acrylate monomer.

6. The preparation method according to claim 2, characterized in that, In the pre-complexation reaction, the solvent used for dissolution is at least one of tetrahydrofuran, toluene, dichloromethane, N-methylpyrrolidone, dimethyl sulfoxide, N,N-dimethylformamide, 1,4-dioxane, dichloromethane, and chloroform.

7. The preparation method according to claim 1, characterized in that, In Step 2, the copolymerization reaction specifically includes: Set the gas pressure range of the ethylene high-pressure reactor to 4-10 MPa, set the stirring rate and react for 1-12 h, precipitate the reaction solution, and obtain the ethylene-tetrahydrofurfuryl acrylate binary copolymer after concentration and drying.

8. The preparation method according to claim 7, wherein The copolymerization reaction in Step 2 includes: Pour the mixed solution E into the reaction kettle of the ethylene high-pressure reactor, flush the reaction pipeline with ethylene gas 3 times, then close the outlet valve, and adjust the pressure of ethylene gas in the reaction kettle to 4-10 MPa; Set the reaction temperature at 40-60 °C, the stirring speed at 50-400 r / min, and start heating and stirring; record the time when the predetermined temperature, speed, and ethylene pressure are reached simultaneously as the start time of the polymerization reaction; After reacting for 6-12 h, pour the reaction solution into a precipitant for precipitation, concentrate, filter by suction, and vacuum dry for 12-48 h to obtain the ethylene-tetrahydrofurfuryl acrylate binary copolymer.

9. The tetrahydrofurfuryl acrylate-ethylene binary copolymer obtained by the preparation method according to any one of claims 1-8, It is characterized in that The chemical structure is: Wherein, m represents the number of repeating units of the tetrahydrofurfuryl acrylate structural unit, and n represents the number of repeating units of the ethylene structural unit; In the sequence structure of the binary copolymer, the proportion of the alternating sequence is 20 mol% - 30 mol%; The weight-average molecular weight range of the binary copolymer is 10,000 - 20,000; In the binary copolymer, the ethylene insertion rate is not less than 30 mol%.

10. The tetrahydrofurfuryl acrylate-ethylene binary copolymer according to claim 9, wherein The ethylene insertion rate range is 30 mol% - 45 mol%.

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