Active cationic polymerization coupling agent, its preparation method and application

Abstract

This invention belongs to the field of polymer materials technology, specifically to active cationic polymerization coupling agents, their preparation methods, and applications. The coupling agent of this invention is 1,2-bis[4-[1-(4-methoxyphenyl)vinyl]phenyl]ethane, denoted as bis-DPE-OMe; specifically, 1,2-bis(4-acetylphenyl)ethane is synthesized from 1,2-bisphenylethane via a Friedel-Crafts acylation reaction; then, 1,2-bis[4-[1-hydroxy-1-(4-methoxyphenyl)-1-ethyl]phenyl]ethane is synthesized via a Grignard reaction; finally, the target product is obtained through intramolecular dehydration. This coupling agent can be used to couple active chain ends to obtain homopolymers and block copolymers, including for the coupling of polyisobutylene and poly(isobutylene- b Poly(styrene-) diblock copolymers were coupled to prepare poly(styrene-) b -Isobutylene- b (-Styrene). Compared with existing technologies, this invention synthesizes a novel and highly efficient cationic polymerization coupling agent. The synthesis process of the coupling agent is simple and it is easy to achieve coupling to the ends of the active PIB chains.

Description

Technical Field

[0001] This invention belongs to the field of polymer materials technology, specifically relating to active cationic polymeric coupling agents, their preparation methods, and applications. Background Technology

[0002] In living cationic polymerization, several substituted coupling agents (such as silyl enol ether compounds and malonate anions) are used for the coupling of polyisobutyl vinyl ether and polyα-methylstyrene, but this is limited to the coupling of low molecular weight polymers (DPn ~ 10), and the coupling efficiency is not high (Higashimura, T, Macromolecules 1996, 29:1862-1866.).

[0003] 1,1-Diphenylethylene (DPE) is widely used in anionic polymerization due to its steric hindrance and monoaddition properties (He, J. Eur. Polym. J. 2015, 65: 171-190.). Faust et al. introduced DPE into living cationic polymerization and found that it had a satisfactory end-capping rate. The resulting diphenylalkyl cations could efficiently initiate the cationic polymerization of active monomers (Faust, RJ Macromol. Sci. A 1995, 32: 1137-1153.). Utilizing its end-capping properties, Faust et al. attached specific functional groups to the para-position of the DPE phenyl group, using it as a terminal functionalizing agent, or synthesized bis-DPE compounds as coupling agents, achieving the coupling of active PIB cations (Faust, R. Macromolecules 1997, 30: 198-203). Utilizing its end-capping and re-initiation functions, they achieved block copolymerization of monomers with significantly different reactivities by adjusting the acidity of Lewis acids. They also used A2 compounds coupled with bis-DPE coupling agents to initiate the synthesis of polymers with precise structures such as A2B2 (Faust, R. Macromolecules 1998, 31: ). 2480-2487.). Among them, the bis-DPE coupling agent has been used in the process of coupling the active chain of poly(styrene-b-isobutylene) (PSt-PIB) diblock copolymer to poly(styrene-b-isobutylene-b-styrene) (SIBS), but the coupling rate is not high (Faust, R. Macromolecules 1999, 32: 5487-5494.). Summary of the Invention

[0004] The purpose of this invention is to provide a novel, highly efficient active cationic polymeric coupling agent, its preparation method, and its application in obtaining homopolymers and block copolymers by coupling active chain ends.

[0005] The active cationic polymerization coupling agent bis-DPE-OR1 provided by this invention has the following structural formula:

[0006] ;

[0007] Wherein, R is an alkyl group, containing -(CH2). n - , n is 1-100, and its isomers, n is preferably 2-20, more preferably 2. R1 is H or an electron-donating group, wherein the electron-donating group is an alkyl group containing -C m H 2m+1 m is 1-100, and its isomers, m is preferably 1-10, more preferably 1.

[0008] When R is -(CH2)2- and R1 is -CH3 (i.e., n = 2, m = 1), it is 1,2-bis[4-[1-(4-methoxyphenyl)vinyl]phenyl]ethane, denoted as bis-DPE-OMe, with the following structural formula:

[0009] ;

[0010] The preparation method of the active cationic polymeric coupling agent provided by the present invention has the following reaction equation:

[0011] ;

[0012] The specific steps are as follows:

[0013] Step 1, Friedel-Crafts acylation reaction: Compound I and acetyl chloride undergo Friedel-Crafts acylation reaction in an aprotic solvent under the catalysis of Lewis acid to generate compound II. After the reaction is completed, the mixture is quenched with an appropriate amount of glacial hydrochloric acid, then separated, washed, dried, concentrated under reduced pressure, and finally purified by recrystallization.

[0014] Step 2, Grignard reaction: Compound II and Grignard reagent undergo the Grignard reaction in an ether solvent to generate compound III. After the reaction is complete, the mixture is quenched with an appropriate amount of glacial hydrochloric acid, then separated, washed, dried, concentrated under reduced pressure, and then transferred to the next step without further purification.

[0015] Step 3, Dehydration reaction: Compound III is dehydrated by reflux in a Dean-Stark tube in a nonpolar inert solvent under the action of a protic acid catalyst to generate bis-DPE-OR1. After washing, drying, and concentration, it is finally recrystallized with a lower alcohol and filtered to obtain a bright silver flaky crystal product. Finally, it is dried to obtain a bis-DPE coupling agent product with a purity > 99.0%, denoted as bis-DPE-OR1.

[0016] Furthermore:

[0017] In step one, the Lewis acid is selected from ferric chloride, aluminum chloride, boron chloride, titanium tetrachloride, and tin tetrabromide, preferably aluminum chloride. The aprotic solvent is selected from dichloromethane, chloroform, carbon tetrachloride, and 1,2-dichloroethane, preferably dichloromethane.

[0018] The reaction temperature in step one is -10 ℃ ~ 10 ℃, preferably -5 ℃ ~ 5 ℃. The molar ratio of compound I, acetyl chloride and Lewis acid is (1-10): (1-10): (1-10), preferably 1: (5-6): (8-10), for example: 1:5:8, 1:6:8, 1:6:9, 1:6:10.

[0019] In step two, X in the Grignard reagent is chlorine, bromine, or iodine, preferably bromine, and R1 is H or an electron-donating group, wherein the electron-donating group is an alkyl group containing -C. m H 2m+1 The molar ratio of compound II to Grignard reagent is 1:(5-10), preferably 1:6. The m is 1-100, and its isomers are also present.

[0020] The reaction temperature in step two is -10 ℃ to 10 ℃, preferably -5 ℃ to 0 ℃. The ether solvent is selected from diethyl ether, diethyl ether, methyl ethyl ether, isopropyl ether, diisopropyl ether, n-butyl ether, dibutyl ether, isopentyl ether, anisole, phenethyl ether, tetrahydrofuran, 2-methyltetrahydrofuran, 1,4-dioxane, ethylene oxide, epichlorohydrin, epichlorohydrin, methyl ether, dimethoxymethane, diethoxymethane, 1,1-dimethoxyethane, 1,1-diethoxyethane, diethylene glycol dimethyl ether, diethylene glycol ethyl ether, ethylene glycol dimethyl ether, dibenzyl ether, tetrahydropyran, preferably 2-methyltetrahydrofuran or tetrahydrofuran, more preferably 2-methyltetrahydrofuran.

[0021] In step three, the nonpolar inert solvent is selected from xylene, toluene, benzene, and carbon tetrachloride, preferably toluene. The protic acid is selected from hydrochloric acid, sulfuric acid, phosphoric acid, p-toluenesulfonic acid, and methanesulfonic acid, preferably p-toluenesulfonic acid. The lower alcohol used for recrystallization is selected from methanol, ethanol, and isopropanol, preferably ethanol.

[0022] This invention also provides the application of the above-mentioned active cationic polymerization coupling agent bis-DPE-OR1 in obtaining homopolymers and block copolymers by coupling active chain ends, specifically:

[0023] Using a composite solvent of alkane and halogenated hydrocarbon, at low temperature, a co-initiator system consisting of a proton trap additive, an aromatic initiator, and a Lewis acid is used to perform living cationic polymerization of monomers. The active chain ends of the polymer can be coupled with the coupling agent bis-DPE-OR1 to obtain homopolymers or block copolymers.

[0024] The synthesis process of the above polymer uses a co-initiation system including initiator 1,3-di-tert-butyl-5-cumyl ether, co-initiator titanium tetrachloride and proton trap 2,6-di-tert-butylpyridine, and uses a mixed solvent of methylcyclohexane and dichloromethane (v / v 60 / 40).

[0025] In this invention, the monomers are isobutylene, isoprene, butadiene, styrene, p-methylstyrene, p-methoxystyrene, p-tert-butoxystyrene, p-hydroxystyrene, p-chlorostyrene, p-chloromethylstyrene, indene, p-fluorostyrene, N-vinylcarbazole, vinylpyrrolidone, coumarone, and alkyl vinyl ethers.

[0026] Preferred monomers are isobutylene and styrene; for example, polyisobutylene obtained by polymerization of isobutylene is coupled with a coupling agent bis-DPE-OMe to form polyisobutylene with a higher molecular weight; further, poly(styrene-b-isobutylene) (PSt-PIB) obtained by polymerization of styrene is coupled with a coupling agent bis-DPE-OMe to form poly(styrene-b-isobutylene-b-styrene) (SIBS) triblock thermoplastic elastomer; wherein the molar ratio of IB monomer to St monomer is (60-90):(10-40).

[0027] In this invention, when the polyisobutylene homopolymer is synthesized and then coupled, the molar ratio of the initiator to the isobutylene monomer is 1:(1-20000), preferably 1:(10-2000), for example: 1:10, 1:50, 1:100, 1:200, 1:500, 1:1000, 1:2000.

[0028] In this invention, when the PSt-PIB diblock copolymer is coupled to form SIBS, the molar ratio of IB monomer to St monomer is (1 - 100):(1 - 100), for example: 60:40, 65:35, 70:30, 75:25, 80:20, 85:15, 90:10.

[0029] In this invention, the molecular weight of the polymer coupling precursor is 100-200000, preferably 1500-200000.

[0030] In this invention, when adding the coupling agent bis-DPE-OR1 for coupling, the coupling agent is dissolved in the same composite solvent as the polymerization reaction before being added.

[0031] In this invention, the active center is identified based on the characteristics of monomer chain transfer, such that the molar ratio of the active center to the coupling agent bis-DPE-OR1 is (1.5-3):1, preferably 2:1;

[0032] In this invention, the temperature for the active cationic polymerization reaction and coupling is 0 ℃ ~ -100 ℃, preferably -80 ℃ ~ -70 ℃, and is prepared by an ethyl acetate / liquid nitrogen bath.

[0033] In this invention, the structure of the coupling agent, the molecular weight of the polymer, the coupling efficiency, and the mechanical properties were characterized by proton nuclear magnetic resonance spectroscopy, gel permeation chromatography, and an electronic universal testing machine.

[0034] The coupling products obtained by this invention have important applications in biomedical materials (such as artificial heart valves, drug-eluting stents, glaucoma drainage tubes, and artificial ureters).

[0035] The main technical features and functional advantages of this invention are:

[0036] This invention provides a novel coupling agent for living cationic polymerization. By introducing an electron-donating alkoxy group, a bis-DPE type coupling agent, bis-DPE-OR1, is designed and synthesized. When the alkyl group is methyl, it is bis-DPE-OMe. The entire process requires only three reaction steps and two recrystallizations to obtain a high-purity product. The synthesis method is simple and easy to implement, with high yield, and can achieve efficient coupling of active cations in polymers such as PIB, providing a reliable route for the rapid preparation of block copolymers. Attached Figure Description

[0037] Figure 1 The 1H NMR spectrum of the coupling agent bis-DPE-OMe in Example 1 is shown.

[0038] Figure 2 The results are GPC test results taken from the precursor PIB and coupling process in Example 2.

[0039] Figure 3 The above are the proton NMR spectra of the precursor PIB-22(A) and the coupling product C-25(B) in Example 2.

[0040] Figure 4 PSt-PIB(M) in Example 3 p = 5.84 × 10 4 SIBS (M) coupling p = 1.17 × 10 5 The stress-strain curve of the sample.

[0041] Figure 5The image shows the GPC-RID signal of the PSt-PIB coupling process to form SIBS in Example 3, and the peak separation processing of the coupling products. Detailed Implementation

[0042] Example 1, Synthesis of coupling agent bis-DPE-OMe:

[0043] The synthetic route for coupling agents is as follows:

[0044] The specific steps for synthesizing coupling agents are as follows:

[0045] (1) All glassware must be dried in a forced-air drying oven at 120 °C for 24 h before use. Add anhydrous AlCl3 (6.5 g, 0.050 mol) to a round-bottom flask, evacuate and heat with a hot gun, and then fill with argon. Repeat this process three times to ensure that the reaction flask is dry. Connect the CaCl2 drying tower, buffer bottle and gas washing bottle containing NaOH saturated solution as a tail gas treatment device to absorb the HCl gas generated during the reaction and balance the gas pressure. 8.5 mL of anhydrous dichloromethane was injected into a round-bottom flask using a syringe. This process generated a large amount of gas. After stirring for 20 minutes, acetyl chloride (3.6 mL, 0.050 mol) was injected using a syringe. After stirring for another 20 minutes, 1,2-diphenylethane (5.0 g, 0.020 mol) was dissolved in 1.5 mL of anhydrous dichloromethane and added dropwise using a syringe. After stirring for 4 hours, the reaction mixture was quenched in a mixture of 10 mL of 10% hydrochloric acid and 20 g of ice. The mixture was separated, and the organic phase was washed with deionized water until neutral, dried over anhydrous magnesium sulfate, and filtered. The organic phase was concentrated by rotary evaporation to obtain a yellowish-brown solid product, which was recrystallized from anhydrous ethanol. The resulting yellowish-brown crystals were filtered, dried in a fume hood, and then dried in a vacuum oven for 24 hours to obtain 4.5 g of the product 1,2-bis(4-acetylphenyl)ethane, with a yield of 80%.

[0046] (2) The product from the first step, 1,2-bis(4-acetylphenyl)ethane (5.0 g, 0.015 mol), was dissolved in 80 mL of tetrahydrofuran. The solution was then slowly added dropwise to a 1M solution of magnesium methoxybromide / tetrahydrofuran (60 mL, 0.060 mol). After the addition was complete, the reaction system was kept at 50 °C for 4 h, and the reaction was monitored by thin-layer chromatography until the substrate was completely consumed. The reaction system was then slowly poured into 100 mL of 10% glacial hydrochloric acid solution to quench the reaction. The organic phase was extracted with toluene, separated, washed until neutral, dried over anhydrous magnesium sulfate, and filtered. An organic mixture containing 1,2-bis[4-[1-hydroxy-1-(4-methoxyphenyl)-1-ethyl]phenyl]ethane was obtained. No purification was required; the next step was performed directly.

[0047] (3) Add a catalytic amount of p-toluenesulfonic acid to the organic mixture from step 2, and reflux and dehydrate using a Dean-Stark tube for 4 h. Wash with deionized water until neutral, then concentrate by rotary evaporation to obtain a pale yellow solid. Finally, recrystallize with anhydrous ethanol, filter to obtain a bright silver flaky crystal product, and dry the product in a vacuum oven at 50 °C for 24 h to obtain 3.0 g of pure product bis-DPE-OMe, with a yield of 45%.

[0048] Example 2: Coupling synthesis of linear PIBs, the synthetic route is as follows:

[0049] .

[0050] The specific steps are as follows:

[0051] (1) Connect the solvent bottle, polymerization bottle, and isobutylene graduated cylinder in series to a double-row tube, evacuate and heat with a hot gun, then purge with argon. Repeat this process three times to ensure the apparatus is dry, and finally maintain the vacuum state inside the apparatus. Add 40 mL of dichloromethane, 60 mL of methylcyclohexane (MeCHx), and 5 mL of 1 M triethylaluminum / n-hexane solution to the solvent bottle. After removing impurities for 24 hours, slowly heat the solvent bottle to 80 °C. Place the polymerization bottle in a liquid nitrogen bath and flash evaporate the solvent into the polymerization bottle, then liquefy it by heating. Cool the polymerization bottle and isobutylene graduated cylinder in an ethyl acetate / liquid nitrogen bath, open the isobutylene gas path, dry it in a drying tower, liquefy and collect the isobutylene (3.0 mL, 0.036 mol), and pour it into the polymerization bottle.

[0052] (2) The polymerization flask was pressurized with Ar to a slightly positive pressure. The main initiator 1,3-di-tert-butyl-5-cumyl ether (86 mg, 0.32 mmol) and proton trap 2,6-di-tert-butylpyridine (200 μL, 0.90 mmol) were dissolved in 10 mL of dry methylcyclohexane and injected into the polymerization flask using a syringe. Finally, 1 M of pre-cooled co-initiator titanium tetrachloride / dichloromethane standard solution (6.4 mL, 6.4 mmol) was injected to initiate the polymerization reaction. After polymerization, the coupling agent (74 mg, 0.16 mmol) was dissolved in 5 mL of dry dichloromethane and injected into the polymerization flask for coupling. Methanol was injected to terminate the coupling reaction. Midway through the process, at appropriate intervals, 2 mL of sample was taken with a syringe and injected into an appropriate amount of anhydrous methanol to quench and precipitate the sample. An appropriate amount of the precipitate was dissolved in tetrahydrofuran and subjected to GPC analysis. The remaining sample was dissolved in petroleum ether or toluene, drawn up with a syringe, and filtered through a needle filter containing a 0.22 μm polytetrafluoroethylene (PTFE) membrane. The filtrate was precipitated in 12 mL of methanol, forming a semi-transparent gel; the supernatant was discarded. Toluene was then added to dissolve the precipitate, followed by methanol precipitation. This process was repeated six times to obtain a pure polymer. The polymer was then placed in a glass petri dish and covered with aluminum foil. Several small holes were punched in the foil. After drying in a fume hood, the mixture was placed in a vacuum oven at 50 °C for 24 h and then dried for 1H NMR spectroscopy analysis.

[0053] Example 3: Synthesis of SIBS triblock copolymer by coupling PSt-PIB diblock copolymer. The synthetic route is as follows:

[0054] .

[0055] The specific steps are as follows:

[0056] (1) Connect the solvent bottle, polymerization bottle, and isobutylene graduated cylinder in series to a double-row tube, evacuate and heat with a hot gun, then purge with argon. Repeat this process three times to ensure the apparatus is dry, and finally maintain a vacuum state inside the apparatus. Add 40 mL of dichloromethane, 60 mL of methylcyclohexane, and 5 mL of 1 M triethylaluminum / n-hexane solution to the solvent bottle. After removing impurities for 24 hours, slowly heat the solvent bottle to 80 °C. Place the polymerization solution in a nitrogen bath and flash evaporate the solvent into the polymerization bottle, then heat to liquefy it. Cool the polymerization bottle in an ethyl acetate / liquid nitrogen bath.

[0057] (2) The polymerization flask was purged with Ar to a slightly positive pressure. Styrene (4.0 mL, 0.050 mol), the main initiator 1,3-di-tert-butyl-5-cumyl ether (86 mg, 0.32 mmol), and the proton trap 2,6-di-tert-butylpyridine (200 μL, 0.90 mmol) were dissolved in 10 mL of dry methylcyclohexane and injected into the polymerization flask using a syringe. Finally, 1 M of pre-cooled co-initiator titanium tetrachloride / dichloromethane standard solution (6.4 mL, 6.4 mmol) was injected to initiate the polymerization reaction. After synthesizing PSt, the isobutylene graduated cylinder was cooled in an ethyl acetate / liquid nitrogen bath, the isobutylene gas path was opened, and after drying in a drying tower, the isobutylene (10.0 mL, 0.120 mol) was liquefied and collected, and poured into the polymerization flask for block polymerization. After synthesizing PSt-PIB, a coupling agent (37 mg, 0.080 mmol) was dissolved in 5 mL of dry dichloromethane and injected into a polymerization flask for coupling. The coupling dose was less than half that of the monofunctional initiator because the introduction of the St monomer reduced the concentration of the cationic active species. Methanol was injected to terminate the coupling process. Midway through the process, 2 mL of sample was taken with a syringe at appropriate intervals and injected into excess anhydrous methanol to quench and precipitate the precipitate. A small amount of the precipitate was dissolved in tetrahydrofuran and then subjected to GPC analysis.

[0058] Testing of materials prepared in Examples 1, 2, and 3

[0059] (1) The coupling agent bis-DPE-OMe of Example 1 was characterized by proton nuclear magnetic resonance spectroscopy, such as... Figure 1 As shown, the signal peaks at chemical shifts δ = 7.26, 7.16, and 6.87 ppm are attributed to hydrogen on the benzene ring, the peak at δ = 5.36 ppm is attributed to hydrogen on the vinyl group, the singlet at δ = 3.83 ppm is attributed to hydrogen on the methoxy group, and the singlet at δ = 2.94 ppm is attributed to hydrogen on the methylene group.

[0060] (2) The molecular weight of the coupling precursor PIB and the coupling process samples from Example 2 were tested and analyzed by gel permeation chromatography, such as... Figure 3 As shown, C-2 represents 2 minutes of coupling, where a clear bimodal distribution appears, indicating a mixture of initial PIB and coupling product. C-5 shows that the coupling product dominates after 5 minutes of coupling. From C-2 to C-5 and then to C-8, with intervals of 3 minutes, a clear decrease in the coupling rate can be observed. By C-16, a single peak has formed, with the molecular weight approximately doubling, indicating the coupling reaction is nearing completion; it shows no significant difference from the image at C-25. The M value at C-25... nThe smaller value compared to C-16 may be due to errors in instrument timing or baseline taking during integration. Throughout the coupling reaction, the molecular weight distribution first broadens and then narrows until the GPC differential signal plot shows a single peak. Peak separation was performed on the GPC plots of the coupling products, and Gaussian fitting was used; all fitting coefficients of determination were R0. 2 > 0.998, the coupling peak and the precursor peak can be clearly distinguished. It can be seen from the figure that the coupling peak of C-16 is almost the same as that of C-25. Therefore, it is believed that the bis-DPE-OMe coupling agent can complete the coupling of active PIB with a number average molecular weight of 11400 within 16-25 minutes. Among them, the ratio of the area of ​​the coupling peak to the total area is defined as the coupling efficiency (Heller, JJ Polym. Sci. Pol. Chem. 1969, 7(1): 73-81.). The ideal 100% coupling efficiency is difficult to achieve. It requires the active species to react perfectly with an equivalent amount of coupling agent functional groups. The remaining uncoupled part of C-25 in the GPC figure may be caused by chain transfer, inactivation of active species or mismatch of coupling agent dosage.

[0061] (3) The coupling precursor PSt-PIB of Example 3 and the coupling process were sampled and monitored by gel permeation chromatography, and molecular weight analysis was performed, such as... Figure 5 As shown, after 780 minutes of coupling, M will... p = 5.84 × 10 4 Precursor PSt-PIB coupled to M p = 1.17 × 10 5 SIBS was used to perform peak separation on the GPC signal of the coupling products, and Gaussian fitting was applied. The determination coefficients of all fittings were R0. 2 > 0.998, the area of ​​coupled peaks accounts for 53%, the area of ​​uncoupled peaks accounts for 14%, and the area of ​​unblocked peaks accounts for 33%. If the unblocked part is not calculated and only the coupled and uncoupled peaks are compared to calculate the coupling efficiency, the coupling efficiency is 79%.

[0062] (4) The molecular weight of the coupling precursors and coupling products in Examples 2 and 3 was analyzed by gel permeation chromatography, and the characterization results are shown in Table 1:

[0063] Table 1 Synthesis of PIB and PSt-PIB and their final coupling products via living cationic polymerization.

[0064] .

[0065] Figure 4The results of testing the mechanical properties of the coupled SIBS triblock copolymer using an electronic universal testing machine are shown in Example 3. The above coupling agent successfully coupled PSt-PIB into a SIBS triblock thermoplastic elastomer. The coupled SIBS has formed microphase separation, and the hard segment microdomains formed by the polystyrene hard segments have formed physical cross-links, thus exhibiting elasticity and good tensile properties. Its tensile strength is 5.7 MPa, and its elongation at break is 370%, proving that active PSt-PIB can be coupled into a SIBS triblock thermoplastic elastomer using the coupling agent bis-DPE-OMe.

Claims

1. An active cationic polymerization coupling agent, denoted as bis-DPE-OR1, characterized in that, The structural formula is: Wherein, R is an alkyl group, containing -(CH2). n - , n is 1-100, and its isomers; R1 is H or an electron-donating group, wherein the electron-donating group is an alkyl group containing -C m H 2m+1 , m is 1-100, and its isomers.

2. The active cationic polymeric coupling agent according to claim 1, characterized in that, R is -(CH2)2-, R1 is -CH3, i.e., n = 2, m = 1, which is 1,2-bis[4-[1-(4-methoxyphenyl)vinyl]phenyl]ethane, denoted as bis-DPE-OMe, with the following structural formula: 。 3. A method for preparing the active cationic polymeric coupling agent as described in claim 1 or 2, characterized in that, The reaction equation is as follows: ； The specific steps are as follows: Step 1, Friedel-Crafts acylation reaction: Compound I and acetyl chloride undergo Friedel-Crafts acylation reaction in an aprotic solvent under the catalysis of Lewis acid to generate compound II. After the reaction is completed, the mixture is quenched with an appropriate amount of glacial hydrochloric acid, then separated, washed, dried, concentrated under reduced pressure, and finally purified by recrystallization. Step 2, Grignard reaction: Compound II and Grignard reagent undergo the Grignard reaction in an ether solvent to generate compound III. After the reaction is complete, the mixture is quenched with glacial hydrochloric acid, then separated, washed, dried, concentrated under reduced pressure, and then added to the next step. Step 3, Dehydration reaction: Compound III is dehydrated by reflux in a Dean-Stark tube in a nonpolar inert solvent under the action of a protic acid catalyst to generate bis-DPE-OR1. After washing, drying, and concentration, it is finally purified by recrystallization with a lower alcohol. The product is filtered to obtain a bright silver flaky crystal product, and finally dried to obtain a bis-DPE coupling agent product with a purity > 99.0%, denoted as bis-DPE-OR1.

4. The preparation method according to claim 3, characterized in that, In step one: The Lewis acid is selected from ferric chloride, aluminum chloride, boron chloride, titanium tetrachloride, and tin tetrabromide; The aprotic solvent is selected from dichloromethane, chloroform, carbon tetrachloride, and 1,2-dichloroethane; The reaction temperature is -10 ℃ ~ 10 ℃; The molar ratio of compound I, acetyl chloride, and Lewis acid is (1-10): (1-10): (1-10).

5. The preparation method according to claim 3, characterized in that, In step two: In the Grignard reagent, X is chlorine, bromine, or iodine, and R1 is H or an electron-donating group, wherein the electron-donating group is an alkyl group containing -C. m H 2m+1 m is 1-100, and its isomers; the molar ratio of compound II and Grignard reagent is 1:(5-10); The ether solvents are selected from diethyl ether, diethyl ether, methyl ethyl ether, isopropyl ether, diisopropyl ether, n-butyl ether, dibutyl ether, isopentyl ether, anisole, phenethyl ether, tetrahydrofuran, 2-methyltetrahydrofuran, 1,4-dioxane, ethylene oxide, propylene oxide, epichlorohydrin, methyl ether, dimethoxymethane, diethoxymethane, 1,1-dimethoxyethane, 1,1-diethoxyethane, diethylene glycol dimethyl ether, diethylene glycol ethyl ether, ethylene glycol dimethyl ether, dibenzyl ether, and tetrahydropyran; The reaction temperature is -10 ℃ ~ 10℃.

6. The preparation method according to claim 3, characterized in that, In step three: The nonpolar inert solvent is selected from xylene, toluene, benzene, and carbon tetrachloride; The protic acid is selected from hydrochloric acid, sulfuric acid, phosphoric acid, p-toluenesulfonic acid, and methanesulfonic acid; The lower alcohol is selected from methanol, ethanol, and isopropanol.

7. The application of the active cationic polymerization coupling agent as described in claim 1 or 2 in obtaining homopolymers and block copolymers by coupling active chain ends, specifically as follows: In a composite solvent of alkane and halogenated hydrocarbon, at low temperature, a system of proton trap additives, aromatic initiators and Lewis acid co-initiators is used to perform living cationic polymerization of monomers. The active polymer chains are coupled with coupling agent bis-DPE-OR1 to obtain homopolymers or block copolymers.

8. The application according to claim 7, characterized in that, The monomers are selected from isobutylene, isoprene, butadiene, styrene, p-methylstyrene, p-methoxystyrene, p-tert-butoxystyrene, p-hydroxystyrene, p-chlorostyrene, p-chloromethylstyrene, indene, p-fluorostyrene, N-vinylcarbazole, vinylpyrrolidone, coumarone, and alkyl vinyl ethers.

9. The application according to claim 8, characterized in that: In the initiation system, the initiator is 1,3-di-tert-butyl-5-cumyl ether, the co-initiator is titanium tetrachloride, and the proton trap is 2,6-di-tert-butylpyridine; The molar ratio of the initiator to the proton trap is 1:(0-10); The molar ratio of initiator to isobutylene monomer is 1:(1-20000); The molecular weight of polymer coupling precursors is 100 – 200,000; After the polymerization reaction is completed, coupling agent bis-DPE-OR1 is added for coupling. The coupling agent is dissolved in the same composite solvent as the polymerization reaction before being added. The temperature for the active cationic polymerization reaction and coupling is 0 ℃ ~ 100 ℃; The molar ratio of the active site to the coupling agent bis-DPE-OR1 is (1.5-3):

1.

10. The application according to claim 9, characterized in that, The monomers are isobutylene and styrene; specifically, polyisobutylene obtained by polymerization of isobutylene is coupled with a coupling agent bis-DPE-OMe to form polyisobutylene with a higher molecular weight; further, poly(styrene-b-isobutylene) (PSt-PIB) obtained by polymerization of styrene is coupled with a coupling agent bis-DPE-OMe to form poly(styrene-b-isobutylene-b-styrene) (SIBS) triblock thermoplastic elastomer; wherein, the molar ratio of IB monomer to St monomer is (60-90):(10-40).

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