Polyisobutylene-based copolymer and preparation method therefor

Abstract

The present invention belongs to the field of polymer compounds, and particularly relates to a thermally cross-linkable polyisobutylene-based block copolymer having a regular structure and a preparation method therefor. In the present invention, the polymerization of a first monomer IB is firstly initiated by means of active / controllable cationic polymerization; an end-capping reagent is then added thereto for end capping, so as to obtain a stable PIB+ active center; and a regulator is then added thereto to regulate the Lewis acidity and reaction activity of the system; and a second monomer 4-VBCB is then added thereto to continue the polymerization reaction, so as to prepare the polyisobutylene-based copolymer. The polyisobutylene-based copolymer of the present invention has good mechanical properties after being thermal crosslinked.

Description

Polyisobutylene-based copolymers and methods for making the same TECHNICAL FIELD

[0001] The present invention belongs to the field of high molecular compounds, and particularly relates to a linear or star-shaped polyisobutylene-based block copolymer with a regular structure and capable of being heat-crosslinked and a preparation method thereof. BACKGROUND

[0002] Isobutylene (IB) is one of the cationic polymerizable monomers, and at present, polyisobutylene (PIB) can only be prepared by cationic polymerization. PIB has been widely reported in commercial application scenarios, and the alternating structure of secondary carbon and quaternary carbon in its main chain makes it have excellent thermal stability, chemical stability, and unparalleled biocompatibility. However, except for PIB with ultra-high molecular weight, PIB is generally a liquid polymer without strength. With the emergence of active cationic polymerization technology, it becomes possible to prepare copolymers based on PIB. Poly(styrene-b-polyisobutylene-b-styrene) (SIBS) is a typical copolymer, in which the two end polystyrene (PS) serves as a hard segment as a physical crosslinking point, and the middle PIB serves as a soft segment; the two phases are incompatible to form a microphase separation structure, thereby having basic mechanical properties, and the physical properties of the copolymer can be adjusted in a wide range by adjusting the ratio of the soft and hard segments. Moreover, SIBS has excellent biocompatibility and has achieved great success in biomedical applications. However, the physical crosslinking structure in SIBS is limited by the glass transition temperature (Tg) of styrene, and has poor creep resistance and heat resistance.

[0003] Patent CN101918461B reports a monomer 4-vinylbenzocyclobutene (4VBCB) with a fused ring, which is used as a second monomer and also as a crosslinking agent to copolymerize with IB to form a PIB-co-4VBCB thermosetting random copolymer with random distribution of two monomer units. The copolymer has similar properties to PIB before crosslinking, and can directly form chemical crosslinking by heating. The crosslinked copolymer has more excellent chemical stability, thermal stability, oxidation resistance, and creep resistance, which well makes up for the performance defects of SIBS. However, in the polymerization process, various complex side reactions will inevitably occur in this random copolymerization method, so that the molecular weight of the final product is uncontrollable, and the mass content of the second monomer is also uncontrollable. Moreover, due to the difference in activity of the two monomers, the molecular weight of the copolymer product is often low, the content of the crosslinking agent is low, and the yield is low, thereby limiting the application of the copolymer.

[0004] SUMMARY

[0005] To improve the above problems, the present application provides a thermosetting elastomer polyisobutylene-based copolymer with regular structure and a preparation method thereof. The method is active / controllable cationic polymerization, which can prepare linear two-block copolymer PIB-b-P4VBCB (polyisobutylene-b-poly-4-vinylbenzocyclobutene), three-block copolymer P4VBCB-b-PIB-b-P4VBCB (poly-4-vinylbenzocyclobutene-b-polyisobutylene-b-poly-4-vinylbenzocyclobutene) or star-shaped block copolymer with regular structure sequence, controllable molecular weight, controllable mass content of second monomer and narrow distribution. By adjusting the molecular weight or structure unit ratio of the product, polyisobutylene-based copolymer thermosetting elastomer with various mechanical properties can be obtained. After high-temperature crosslinking of the polyisobutylene-based copolymer thermosetting elastomer, an elastomer containing stable chemical crosslinking structure can be obtained.

[0006] The first technical problem to be solved by the present application is to provide a preparation method of a polyisobutylene-based copolymer, comprising the following steps: first initiating polymerization of a first monomer IB by active / controllable cationic polymerization, then adding an end-capping agent to cap to obtain stable PIB+ active center, and then adding a regulator to adjust the Lewis acidity and reaction activity of the system; then adding a second monomer 4-VBCB to continue the polymerization reaction, terminating the reaction, and after treatment, the polyisobutylene-based copolymer is obtained.

[0007] Specifically, the preparation method of the polyisobutylene-based copolymer comprises the following steps: carrying out polymerization reaction of a proton trapping agent, a main initiator, a first part of the first monomer IB and a co-initiator in a solvent, then adding a second part of the first monomer IB to continue the polymerization reaction until the conversion rate of the first monomer is above 95%; then adding an end-capping agent to cap to obtain stable PIB+ active center, and then adding a regulator to adjust the Lewis acidity and reaction activity of the system; then adding a second monomer 4-VBCB to continue the polymerization reaction, terminating the reaction, and after treatment, the polyisobutylene-based copolymer is obtained. Specifically, in the above preparation method, the end-capping agent is at least one of 1,1-diphenyl ethylene (DPF), 1,1-di-p-tolyl ethylene (DTE), 2-methyl furan and 2-tert-butyl furan. Preferably, the end-capping agent is 1,1-diphenyl ethylene or 1,1-di-p-tolyl ethylene.

[0008] Specifically, in the above preparation method, the regulator is at least one of Ti(OR)4, SnBr4, SnCl4, n-Bu4NCl and BCl3, wherein R is C1-4 alkyl. Preferably, the regulator is titanium isopropoxide (Ti(OiPr)4) or Bu4NCl.

[0009] Specifically, in the above preparation method, the main initiator is or 2-chloro-2,4,4-trimethylpentane; wherein R1 is methyl, Cl or methoxy, and R2 and R3 are each independently Cl or methoxy.

[0010] Specifically, in the preparation method, the co-initiator is at least one of titanium tetrachloride, iron chloride, boron trifluoride, boron trichloride, gallium trichloride, aluminum chloride, and alkyl aluminum chloride. Preferably, the co-initiator is titanium tetrachloride. The alkyl aluminum chloride is selected from diethyl aluminum chloride, ethyl aluminum sesquichloride, ethyl aluminum dichloride, and the like.

[0011] Specifically, in the preparation method, the proton trap is at least one of 2,6-di-tert-butylpyridine, 2,6-di-tert-butyl-4-methylpyridine, and 2,4,6-tri-tert-butylpyridine. Preferably, the proton trap is 2,6-di-tert-butylpyridine.

[0012] Specifically, in the preparation method, the solvent is a mixed solvent of solvent A and solvent B; wherein the solvent A is at least one of chloromethane, dichloromethane, and trichloromethane, and the solvent B is at least one of n-hexane, cyclohexane, and methylcyclohexane.

[0013] Further, in the preparation method, the volume ratio B / A of the mixed solvent is 7:3, 6:4, or 5:5. Preferably, the volume ratio B / A of the mixed solvent is 6:4.

[0014] Further, in the preparation method, the molar ratio of the first monomer to the second monomer is (60-99):(40-1).

[0015] Further, in the preparation method, the molar ratio of the main initiator to the first monomer is 1:(50-1000).

[0016] Further, in the preparation method, the molar ratio of the main initiator to the co-initiator is 1:(2-64).

[0017] Further, in the preparation method, the molar ratio of the capping agent to the main initiator is 1:(1-10).

[0018] Further, in the preparation method, the molar ratio of the adjusting agent to the capping agent is (1-64):1.

[0019] Further, in the preparation method, the molar ratio of the proton trap to the capping agent is 1:(1-10).

[0020] Further, in the preparation method, the second monomer is added to the system after being mixed with the solvent B. Further, the volume ratio of the second monomer to the solvent B is 1:(1-5).

[0021] Further, in the preparation method, the first part of the first monomer accounts for 5-30 wt% of the total amount of the first monomer, and the second part of the first monomer accounts for 70-95 wt% of the total amount of the first monomer.

[0022] Further, in the above preparation method, the mass fraction of the total mass of the first monomer and the second monomer in the reaction system is 10-50%.

[0023] Specifically, in the above preparation method, each reaction is carried out in anhydrous and anaerobic atmosphere. Preferably, each reaction is carried out in an inert atmosphere.

[0024] Specifically, in the above preparation method, the reaction temperature is-50- -100℃. Preferably, the reaction temperature is-80℃.

[0025] Specifically, in the above preparation method, the solvent is pre-cooled for 5-20 min at the reaction temperature before the proton capture agent, the main initiator and the first part of the first monomer are added. After the proton capture agent, the main initiator and the first part of the first monomer are added to the solvent, the whole system is pre-cooled for 5-20 min at the reaction temperature before the co-initiator is added.

[0026] Specifically, in the above preparation method, the second part of the first monomer is added after the system is subjected to polymerization reaction for 5-30 min.

[0027] Specifically, in the above preparation method, the end-capping agent is added after the second part of the first monomer is added and the polymerization reaction is continued for 60-120 min.

[0028] Specifically, in the above preparation method, the adjusting agent is added after the end-capping agent is added and the reaction is continued for 30-120 min.

[0029] Specifically, in the above preparation method, the second monomer is added after the adjusting agent is added and the reaction is continued for 5-30 min.

[0030] Specifically, in the above preparation method, the reaction is terminated after the second monomer is added and the reaction is continued for 5-120 min. The termination of the reaction is achieved by adding methanol.

[0031] Specifically, in the above preparation method, the conversion rate of the first monomer is 95-100%.

[0032] Specifically, in the above preparation method, the conversion rate of the second monomer is 10-70%.

[0033] The second technical problem to be solved by the present application is to provide a polyisobutylene-based copolymer prepared by the above preparation method.

[0034] Further, in the above polyisobutylene-based copolymer, the number average molecular weight of the copolymer is 1000-5x10 5 g / mol, and the molecular weight distribution is 1.01-1.30.

[0035] Further, the second monomer mass fraction in the above polyisobutylene-based copolymer is 1-50 wt%. The first monomer conversion rate is 95-100%. The second monomer conversion rate is 10-70%.

[0036] A third technical problem to be solved by the present application is to provide a polymer obtained by crosslinking the above polyisobutylene-based copolymer. The crosslinking conditions are heating at 150-300℃ for 5-60 min.

[0037] The present application prepares a polyisobutylene-based block copolymer with controllable molecular weight, controllable content of each block, controllable structure sequence, and controllable soft / hard segment ratio by active / controllable cationic polymerization, wherein polyisobutylene (PIB) is the soft segment and poly-4-vinylbenzocyclobutene (P-4VBCB) is the hard segment. The present application can well control the molecular weight and soft / hard segment ratio of the polyisobutylene-based block copolymer, and the polymer has a narrow molecular weight distribution. The present application has the advantages of high monomer conversion rate and yield. The copolymer prepared by the present application has controllable molecular weight, crosslinker content, and ordered structure, which greatly improves the yield and mechanical properties, and can be widely used in biological medicine, tire inner tube, medical packaging, wire, cable, adhesive tape, rubber tube, various mechanical products, vibration isolation, waterproof sheet for building, sealing and caulking materials, chewing gum, etc. BRIEF DESCRIPTION OF DRAWINGS

[0038] Figure 1 is a structural schematic diagram of the block copolymer prepared by selecting three different initiators.

[0039] Figure 2 is the nuclear magnetic hydrogen spectrum of the final product of Example 2. The mass fraction of the second monomer in the polymer can be calculated from the integral values of the main characteristic peaks in the figure. The calculation method is as follows:

[0040] A / 4*130.19 / (A / 4*130.19+B / 6*56)*100 wherein A and B refer to the integral area of the characteristic peak

[0041] The calculated mass fraction of the second monomer in the final product is 9.81%.

[0042] Figure 3 is the nuclear magnetic hydrogen spectrum of the final product of the comparative example, and the mass fraction of the second monomer is also calculated as 1.61%.

[0043] Figure 4 is the differential (RI) spectrum of the first monomer of the three-block copolymer of Example 2 at different reaction times. All the elution curves are normally distributed without tailing. And with the extension of reaction time, the peak time moves forward, indicating that the molecular weight is continuously increasing. It can be clearly seen that the reaction is active / controllable polymerization.

[0044] Figure 5 shows the differential index (RI) spectra of the second monomer of the triblock copolymer described in Example 2 at various reaction times. All elution curves show a normal distribution with no tailing. Furthermore, the peak time shifts earlier with increasing reaction time, indicating a continuous increase in molecular weight. This clearly demonstrates a living / controlled polymerization.

[0045] Figure 6 is the SEC-MALS-UV-RI spectrum of the final triblock copolymer described in Example 2. The UV, differential, and laser peak times are completely consistent, demonstrating high block efficiency and a uniform block structure between the second monomer and the first monomer.

[0046] Figure 7 compares the DSC spectra of the final products of Example 2 and the comparative example. The DSC spectra clearly show that the final product of the comparative example exhibits only a single glass transition temperature (Tg), while the final product of Example 2 exhibits two distinct Tgs, corresponding to the Tgs of the respective homopolymers of the two segments. This demonstrates that the copolymer prepared according to the present invention possesses a well-defined block structure and combines the properties of both homopolymer segments.

[0047] Figure 8 compares the mechanical properties of the products of Examples 1, 2, and 3 and the comparative example after thermal crosslinking. As can be clearly seen from the figure, the maximum tensile strength and elongation at break of the products of the examples are significantly greater than those of the comparative example. When testing the mechanical properties of the examples and comparative examples, the copolymers formed into films after thermal crosslinking were cut into dumbbell-shaped strips according to the ASDM D-412 test standard. Three strips were taken from each sample, and the results were averaged. DETAILED DESCRIPTION

[0048] It is well known in the professional field that in order to achieve high-efficiency block polymerization of multiple monomers in cationic polymerization, the reactivity between the monomers must be similar. For example, the reactivity of IB is similar to that of styrene (St) monomers. Therefore, when preparing IB and St block copolymers, a simple sequential monomer addition method can achieve cationic active / controlled polymerization. However, compared to St, 4VBCB is a monomer with a fused ring structure with an additional four-membered ring on the benzene ring. In a fused ring structure, due to the increased number of rings, electrons can be distributed among more atoms, which may lead to electron density concentration in certain areas. Due to the complexity of its structure and electron distribution, it may show higher reactivity in specific locations, resulting in the high reactivity of 4VBCB. At the same time, the inventors have also specifically verified through experiments that the reactivity of 4VBCB is higher than that of IB. Conventional reactions cannot introduce more 4VBCB, thereby making the resulting copolymer have higher mechanical properties. It can be seen that based on the huge differences in monomer chemical structure, reactivity, polymerization rate, etc. between IB and 4VBCB, it is very difficult to achieve active / controlled cationic polymerization and thus obtain a regular block copolymer by simply adding monomers in a sequential manner.

[0049] The inventors have discovered that, through a living / controlled cationic polymerization method, polymerization of the first monomer (IB) is initiated. After the first monomer is largely converted, a capping agent is added to cap the end of the first monomer to obtain a stable PIB + active center. A modifier is then added to adjust the Lewis acidity and reactivity of the active center, thereby reducing the chain growth rate of the second monomer to less than the chain initiation rate. The second monomer is then added to react, achieving efficient block formation. Furthermore, by controlling the reaction time of the second monomer, the crosslinker content and molecular weight of the copolymer can be easily controlled. After terminating the reaction, a block copolymer with an orderly structure is obtained. This shows that the method of the present invention can introduce more second monomers, resulting in a higher crosslinker content in the product, and thus better mechanical properties of the resulting copolymer after crosslinking.

[0050] Specifically, the preparation method of the polyisobutylene-based copolymer of the present invention comprises the following steps: first, baking and exhausting glassware to remove water and oxygen, then placing it in an inert atmosphere glove box, cooling it to a reaction temperature of -50 to -100°C, sequentially adding solvent A and solvent B, thoroughly mixing and precooling for 5 to 20 minutes, continuously adding a proton scavenger, a main initiator, and the first portion of the first monomer IB, thoroughly mixing and precooling for 5 to 20 minutes, adding a co-initiator, polymerizing for 5 to 30 minutes, adding the second portion of the first monomer IB, continuing the polymerization for 60 to 120 minutes, adding a capping agent, adding a regulator after 30 to 120 minutes, adding a mixture of the second monomer 4VBCB and solvent B after 5 to 30 minutes, continuing the polymerization for 5 to 120 minutes, and then adding methanol to terminate the reaction, precipitating the product with isopropanol, dissolving it with cyclohexane, repeatedly washing it, and drying it to obtain the copolymer.

[0051] In the method of the present invention, the first monomer IB is added in two stages, with the first portion comprising 5 to 30% by weight of the total first monomer amount and the second portion comprising 70 to 95% of the total first monomer amount. Initially adding a small amount of the first monomer to form a stable active center, followed by adding a larger amount of the first monomer to initiate chain growth, avoids the concentrated exotherm during initiation that can lead to side reactions such as chain transfer.

[0052] In the method of the present invention, the combined mass fraction of the first and second monomers in the reaction system is preferably controlled to be 10-50%. Controlling the concentrations of the first and second monomers within this range can control the degree of heat release and facilitate polymerization. The reaction system is the total mass of the entire system. The first and second monomers can be added in amounts as they are added directly.

[0053] In the method of the present invention, the molecular weight of the copolymer can be controlled by the ratio of the monomer to the initiator; at the same time, the longer the polymerization time of the second monomer and the higher the second monomer content, the greater the molecular weight of the copolymer.

[0054] In the method of the present invention, the reaction temperature of the entire system is controlled at -50 to -100° C., preferably -80° C. Once the temperature is determined, it is preferably maintained at this temperature throughout the polymerization process, so each addition preferably includes a pre-cooling step.

[0055] In the method of the present invention, when the main initiator is When the main initiator is When the main initiator is 2-chloro-2,4,4-trimethylpentane (TMPCl), the obtained polyisobutylene-based copolymer is a three-arm star block copolymer, and all three arms are PIB-b-P4VBCB, and the structural schematic diagram is shown in Figure 1; when the main initiator is 2-chloro-2,4,4-trimethylpentane (TMPCl), the obtained polyisobutylene-based copolymer is a diblock copolymer PIB-b-P4VBCB (polyisobutylene-b-polytetravinylphenylpropylcyclobutene), and the structural schematic diagram is shown in Figure 1.

[0056] In the method of the present invention, the first monomer conversion rate is preferably controlled to be 95-100%, that is, 95-100% of the added first monomer participates in the reaction and becomes part of the copolymer. The second monomer conversion rate is preferably controlled to be 10-70%, that is, 10-70% of the added second monomer participates in the reaction and becomes part of the copolymer.

[0057] The polyisobutylene copolymer prepared by the method of the present invention has a number average molecular weight of 1000 to 5×10 5 g / mol, and the molecular weight distribution is 1.01 to 1.30.

[0058] In the polyisobutylene-based copolymer prepared by the method of the present invention, the mass fraction of the second monomer is 1 to 50 wt%, that is, the content of the second monomer block in the final polyisobutylene-based copolymer is 1 to 50 wt%.

[0059] The polyisobutylene-based copolymer prepared by the method of the present invention has excellent mechanical properties and other effects after being heated at 150-300° C. for 5-60 minutes and thermally cross-linked in a flat-plate vulcanizer.

[0060] Example 1 Synthesis of diblock copolymer PIB-b-P4VBCB (polyisobutylene-b-polytetravinylphenylpropylcyclobutene)

[0061] Pour coolant into the cold trap of the anhydrous and oxygen-free glove box and cool it to -80°C. Place a dried polymerization bottle that has been baked and evacuated, add 1L of a 60 / 40 volume ratio of methylcyclohexane / chloromethane mixed solvent, mix well, and precool for 10 minutes; add 0.143mL of a proton scavenger 2,6-di-tert-butylpyridine, 0.64mL of a main initiator 2-chloro-2,4,4-trimethylpentane (TMPCl), and 5.6mL of IB1 in sequence. Precool for 10 minutes, then add 7.0mL of a co-initiator, titanium tetrachloride, and polymerize for 20 minutes before adding IB2. 50mL of the reaction mixture was added and polymerization continued for 80 minutes. 0.15mL of the end-capping agent 1,1-di-p-tolylethylene (DTE) was added. After 60 minutes, 5.4mL of the modifier titanium isopropoxide (Ti(OiPr)4) was added. 10 minutes later, 25mL of the second monomer, 4-vinylbenzocyclobutene (4VBCB), was added. Polymerization continued for 30 minutes before methanol was added to terminate the reaction. The product was precipitated with isopropanol and dissolved in cyclohexane three times before drying. 8g of the dried product was heat-crosslinked in a flat-plate vulcanizer at 200°C for 25 minutes to form the final product.

[0062] Example 2 Synthesis of triblock copolymer P4VBCB-b-PIB-b-P4VBCB (poly(4-vinylbenzocyclobutene-b-polyisobutylene-b-polytetravinylphenylcyclobutene))

[0063] Pour coolant into the cold trap of the anhydrous and oxygen-free glove box and cool it to -80°C. Place a dried polymerization bottle that has been baked and evacuated, add 1 L of a 60 / 40 volume ratio of methylcyclohexane / chloromethane mixed solvent, mix well, and precool for 10 minutes; add 0.143 mL of a proton scavenger 2,6-di-tert-butylpyridine, 0.79 g of a main initiator 5-tert-butyl-1,3-di(methylethylchloro)benzene, and 5.6 mL of IB1 in sequence, precool for 10 minutes, and then add 7.0 mL of a co-initiator, titanium tetrachloride. After 20 minutes of polymerization, add 250 mL of IB. Take 1 mL of sample at 25, 50, 60, 70, and 90 minutes of polymerization, respectively, and terminate with methanol. After 100 minutes of polymerization, 0.15 mL of the end-capping agent 1,1-di-p-tolylethylene (DTE) was added. After 60 minutes, 5.4 mL of the modifier titanium isopropoxide (Ti(OiPr)4) was added. After 10 minutes, 25 mL of the second monomer, 4-vinylbenzocyclobutene (4VBCB), was added. Samples of 1 mL were taken at 5, 10, 20, 30, 40, and 50 minutes, and terminated with methanol. Methanol was added after 60 minutes of polymerization to terminate the reaction. The product was precipitated with isopropanol and dissolved in cyclohexane three times before drying. The final product was weighed to 62.4 g, with an overall yield (total monomer weight / final copolymer weight) of 94.5%. The product was then placed in a platen curing apparatus and thermally crosslinked at 240°C for 5 minutes.

[0064] Example 3 Synthesis of three-arm star block copolymer (PIB-b-P4VBCB)3 (polyisobutylene-b-polytetravinylphenylcyclobutene)3

[0065] Pour coolant into the cold trap of the anhydrous and oxygen-free glove box and cool it to -80°C. Place a dried polymerization bottle that has been baked and evacuated, add 1 L of a 60 / 40 volume ratio of methylcyclohexane / chloromethane mixed solvent, mix well, and precool for 10 minutes. Then add 0.143 mL of a proton scavenger 2,6-di-tert-butylpyridine, 0.85 g of a primary initiator 1,3,5-tris(methylethylchloro)benzene, and 5.6 mL of IB1 in sequence. After precooling for 10 minutes, 7.0 mL of a co-initiator, titanium tetrachloride, was added. After 20 minutes of polymerization, 50 mL of IB2 was added and the polymerization was continued for 80 minutes. 0.15 mL of a capping agent, 1,1-di-p-tolylethylene (DTE), was added. After 60 minutes, 6.8 mL of a regulator, titanium isopropoxide (Ti(OiPr)4), was added. After 15 minutes, 32 mL of a second monomer, 4-vinylbenzocyclobutene (4VBCB), was added. The polymerization was continued for 30 minutes, and methanol was added to terminate the reaction. The product was precipitated with isopropyl alcohol and then dissolved with cyclohexane, and the process was repeated three times before drying. 8 g of the dried product was placed in a flat plate vulcanizer at 240°C for 6 minutes for thermal cross-linking to form a film.

[0066] Comparative Example

[0067] A coolant was pumped into a cold trap in an anhydrous and oxygen-free glove box and cooled to -80°C. A dried, oven-dried polymerization flask was placed in the flask, followed by 1 L of a 60 / 40 (volume) mixture of methylcyclohexane and methyl chloride. Mixed thoroughly, the mixture was then pre-cooled for 10 minutes. Then, 0.143 mL of the proton scavenger 2,6-di-tert-butylpyridine, 0.79 g of the primary initiator 5-tert-butyl-1,3-di(methylethylchloro)benzene, and 5.6 mL of IB1 were added. After pre-cooling for 10 minutes, 7.0 mL of the co-initiator titanium tetrachloride was added. After 20 minutes of polymerization, 50 mL of IB2 and 25 mL of the secondary monomer 4-vinylbenzocyclobutene (4VBCB) were added. After 60 minutes of polymerization, methanol was added to terminate the reaction. The product was precipitated with isopropanol and dissolved in cyclohexane. This process was repeated three times before drying. The final product, 16.7 g, was weighed, yielding 25.3%. The product was then placed in a plate-type vulcanizer and thermally crosslinked at 240°C for 5 minutes.

Claims

1. A process for the preparation of a polyisobutenyl copolymer comprising the steps of: The first monomer IB is first polymerized by active / controllable cationic polymerization, then a capping agent is added to cap to obtain stable PIB+ active center, then a regulator is added to regulate Lewis acidity and reactivity of the system, then the second monomer 4-VBCB is added to continue polymerization, and the reaction is terminated and post-treated to obtain the polyisobutylene-based copolymer.

2. The method of making a polyisobutylene-based copolymer of claim 1, comprising the steps of: The proton trapping agent, the main initiator, the first part of the first monomer IB, and the co-initiator are subjected to polymerization in a solvent, then the second part of the first monomer IB is added to continue polymerization until the conversion rate of the first monomer is above 95%, then a capping agent is added to cap to obtain stable PIB+ active center, then a regulator is added to regulate Lewis acidity and reactivity of the system, then the second monomer 4-VBCB is added to continue polymerization, and the reaction is terminated and post-treated to obtain the polyisobutylene-based copolymer.

3. The production method according to claim 1 or 2, characterized by: The capping agent is at least one of 1,1-diphenyl ethylene, 1,1-di-p-tolyl ethylene, 2-methyl furan, and 2-tert-butyl furan; preferably, the capping agent is 1,1-diphenyl ethylene or 1,1-di-p-tolyl ethylene.

4. The method of any one of claims 1-3, wherein: The modulator is at least one of Ti(OR)4, SnBr4, SnCl4, n-Bu4NCl, BCl3, where R is C 1-4 alkyl; preferably the modulator is titanium isopropoxide or Bu4NCl.

5. The method of any one of claims 1-4, wherein: At least one of the following conditions is met: The main initiator is chloro-2,4,4-trimethylpentane; wherein R1 is methyl, Cl, or methoxy, and R2 and R3 are each independently Cl or methoxy; The co-initiator is at least one of titanium tetrachloride, iron chloride, boron trifluoride, boron trichloride, gallium trichloride, aluminum chloride, and alkyl aluminum chloride; preferably, the co-initiator is titanium tetrachloride; The proton trapping agent is at least one of 2,6-di-tert-butylpyridine, 2,6-di-tert-butyl-4-methylpyridine, and 2,4,6-tri-tert-butylpyridine; preferably, the proton trapping agent is 2,6-di-tert-butylpyridine; The solvent is a mixed solvent of solvent A and solvent B; wherein solvent A is at least one of chloromethane, dichloromethane, and trichloromethane, and solvent B is at least one of n-hexane, cyclohexane, and methylcyclohexane; further, the volume ratio of the mixed solvent B / A is 7:3, 6:4, or 5:

5.

6. The method of any one of claims 1-5, wherein: At least one of the following conditions is met: The molar ratio of the first monomer to the second monomer is (60-99):(40-1); The molar ratio of the main initiator to the first monomer is 1:(50-1000); The molar ratio of the main initiator to the co-initiator is 1:(2-64); The molar ratio of the capping agent to the main initiator is 1:(1-10); The molar ratio of the regulator to the capping agent is (1-64):1; The molar ratio of the proton trapping agent to the capping agent is 1:(1-10); The first part of the first monomer accounts for 5-30wt% of the total amount of the first monomer, and the second part of the first monomer accounts for 70-95wt% of the total amount of the first monomer; The total mass of the first monomer and the second monomer accounts for 10-50% of the mass of the reaction system.

7. The method of any one of claims 1-6, wherein: Each reaction temperature is -50 to -100℃; preferably, -80℃.

8. The method of any one of claims 1-7, wherein: At least one of the following conditions is met: the solvent is pre-cooled for 5-20 minutes before adding the proton capturing agent, the main initiator and the first part of the first monomer; after adding the proton capturing agent, the main initiator and the first part of the first monomer into the solvent, the whole system is pre-cooled for 5-20 minutes at the reaction temperature before adding the co-initiator; The system is polymerized for 5-30 minutes before adding the second part of the first monomer; After adding the second part of the first monomer and continuing the polymerization for 60-120 minutes, the end-capping agent is added; After adding the end-capping agent and continuing the reaction for 30-120 minutes, the adjusting agent is added; After adding the adjusting agent and continuing the reaction for 5-30 minutes, the second monomer is added; After adding the second monomer and continuing the reaction for 5-120 minutes, the reaction is terminated; The conversion rate of the second monomer is 10-70%.

9. A polyisobutylene-based copolymer prepared by the preparation method of any one of claims 1-8.

10. The polyisobutylene-based copolymer of claim 9, wherein: a number average molecular weight of 1000 to 5 x 10 5 g / mol, and a molecular weight distribution of 1.01 to 1.30; Further, the mass fraction of the second monomer is 1-50 wt%.

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