Ether-ester double-ligand complex and application thereof in preparation of high-activity polyisobutene

Abstract

The invention discloses an ether-ester double-ligand complex and an application of the ether-ester double-ligand complex in preparation of high-activity polyisobutene. The ether-ester double-ligand complex comprises a main electron donor, an auxiliary electron donor and an initiator. The stability of the complex is controlled by accurately regulating and controlling the ether / ester molar ratio (such as 5-20) in the composite electron donor system and the halogen type in the main and auxiliary electron donors, the layered regulation and control of electron density are realized through the spatial configuration design, the chain transfer and termination are synergistically inhibited, the preparation of polyisobutene under high monomer concentration is realized, and the monomer has the advantages of high conversion rate and low cost. The polyisobutene is high in activity (high exo-olefin content) and narrow in molecular weight distribution, the exo-olefin content is larger than or equal to 90%, the monomer conversion rate is larger than or equal to 95%, and the molecular weight distribution is narrow (1.2-1.8).

Description

Technical Field

[0001] This invention belongs to the field of polymer synthesis, specifically relating to an ether-ester bis-complex electron donor technology and its application in the preparation of highly active polyisobutylene. Background Technology

[0002] Highly reactive polyisobutylene (HRPIB) is a type of end-rich... exo HRPIB is a specialty polymer containing olefin functional groups (content > 60%, industrial preferred grade ≥ 75%). Its highly reactive double bond structure at the molecular chain ends provides a unique chemical platform for preparing high-performance polymer additives. Through a cyclization addition reaction with maleic anhydride (MA), HRPIB can directionally synthesize polyisobutylene succinimide ashless dispersant. This product exhibits over 40% higher anti-deposition efficiency in lubricating oil systems compared to traditional sulfonates. When a third monomer such as 1-decene and acrylic acid is introduced for ternary copolymerization, the low-temperature embrittlement temperature of the resulting elastomer thickener can be reduced to below -50°C, while the compatibility index with fluororubber seals increases to 0.92 (ASTM D2000 standard). In particular, the polyisobutylene monoamine gasoline detergent prepared via a carbonylation-ammonialysis route reduces intake valve deposits by up to 92% in bench tests, significantly outperforming competing polyetheramine products.

[0003] Current industrial production mainly relies on boron-based (BF3), aluminum-based (AlCl3 / EtAlCl2), and titanium / iron-based catalytic systems, among which BASF's secondary alcohol / ether electron donor regulation technology is representative. Studies have shown a synergistic effect between the pKa value of the oxygen atom in the electron donor and the steric hindrance index (SSI) of the alkyl group: when using isopropanol with pKa=16.5, the monomer conversion can reach 89%, but the resulting product molecular weight distribution width (PDI) reaches 2.8; while using tert-butanol ether with pKa=18.2, although the PDI narrows to 2.3, the reaction rate decreases by 35%. This "activity-selectivity" trade-off can be balanced by adjusting the catalyst ratio when the isobutylene monomer concentration is below 50 wt%. However, when the monomer concentration increases to industrial-grade levels (≥50 wt%), β - The hydrogen transfer reaction rate increases exponentially, causing the proportion of chain termination reactions to surge from 12% to 38%, ultimately leading to three major technical defects: First, the molecular weight distribution broadens to above 3.2, resulting in decreased batch stability of downstream derivatives; second, the end-of-chain... exo - The double bond retention rate falls below the 60% threshold, directly weakening the ability of PIBA-type detergents to capture nanoscale carbon deposits; third, the monomer conversion rate is limited to below 82%, forcing manufacturers to use 3-5 times the solvent circulation volume to maintain the reaction, resulting in an increase in energy consumption costs of 28%-35%.

[0004] Although from an industrial economic perspective, high-concentration polymerization processes have significant advantages: space-time yields can be increased from 12 kg / (m³) of existing technologies. 3 •h) increased to 18kg / (m 3 The solvent recovery unit energy consumption is reduced by 42%, and the carbon emission per unit product is reduced by 0.8 tCO2e / t. However, the activity decay mechanism of the existing catalytic system under high concentration conditions is not yet clear, and the competitive adsorption kinetics between electron donors and isobutylene monomers lack a quantitative model, which means that industrial plants still need to operate at monomer concentrations below 45 wt%. Therefore, how to develop a highly efficient catalytic system suitable for high monomer concentrations, thereby achieving a narrower HRPIB molecular weight distribution (PDI≤2.0) and maintaining end-group activity (…) exo -Double bonds ≥75%) has become a core task for enhancing the international competitiveness of the domestic polyisobutylene industry. Summary of the Invention

[0005] To solve the above-mentioned technical problems, the present invention provides the following technical solution: An ether-ester bis-coefficient complex, comprising a primary electron donor, a secondary electron donor, and an initiator; wherein... The primary electron donor is selected from ether compounds, preferably ether compounds capable of forming stable bidentate or polydentate coordination structures with Lewis acids (e.g., AlCl3, EtAlCl2, BF3, etc.) to construct clusters; the ether compound has the general structural formula shown in Formula I below: Formula I In Formula I, X is selected from F, Cl, or Br; p is selected from integers from 0 to 15, such as 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14 or any range between two numbers; R 1 Selected from unsubstituted or by one, two or more selected from R c The following groups are substituted by the following groups: C1–C5 alkyl, C2–C5 alkenyl, C6–C 10 One of the aryl groups (such as phenyl); R c Selected from F, Cl, Br or C1–C3 alkyl groups; The secondary electron donor is selected from monoester compounds; the general formula of the monoester compound is R. a –C(=O)–O–R b , where R a Selected from C1–C5 straight-chain alkyl groups; R b It is selected from C1–C5 straight-chain alkyl, C1–C5 branched alkyl or C1–C5 cycloalkyl, and the C1–C5 branched alkyl does not contain tertiary carbon atoms; The initiator is selected from at least one of boron-based initiators, aluminum-based initiators, titanium-based initiators, and iron-based initiators.

[0006] According to an embodiment of the present invention, the halogen may be selected from fluorine, chlorine, bromine and iodine, preferably fluorine, chlorine or bromine.

[0007] For example, R 1 Selected from one of the following groups: methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, tert-butyl, chloromethyl, bromomethyl, chloroethyl, bromoethyl, chloropropyl, bromopropyl, chlorobutyl, bromobutyl, vinyl, phenyl, 2,6-dimethylphenyl, 2,6-diethylphenyl, 2,6-diisopropylphenyl.

[0008] According to a preferred embodiment of the present invention, in formula I, R 1 The C1–C3 alkyl group substituted with F, Cl or Br or the C2–C3 alkenyl group substituted with halogen are selected from at least one of 2,2-dichlorodiethyl ether, 2,2-dibromodiethyl ether, bromomethyl methyl ether, 3-bromopropylmethyl ether, 2-chloroethyl vinyl ether, isopropyl-2-bromoethyl ether, chloromethyl methyl ether, and chloromethyl isopropyl ether.

[0009] The inventors discovered that when the radius of halogen atoms in the main electron-donating ether compounds increases, the stability of bidentate or polydentate coordination clusters formed by the complexation of ether compounds with Lewis acids decreases, thereby weakening the polymer's chain growth advantage and exo-double bond selectivity, resulting in varying degrees of deterioration in the polymer's conversion rate, terminal olefin content, and molecular weight distribution.

[0010] Preferably, the monoester compound is selected from at least one of isobutyl propionate, propyl propionate, methyl heptanoate, ethyl octanoate, etc.

[0011] The inventors discovered that the weak coordination of the carbonyl oxygen with the Lewis acid in the monoester compounds of this invention can adjust the acid strength, reduce the chain transfer rate in the polymerization reaction, and improve the molecular weight distribution of the polymer. Furthermore, the spatial arrangement and steric hindrance of the monoester compounds have a significant impact on the polymerization reaction: in linear monoester compounds, R... a The steric hindrance of the functional groups plays a major role in the polymerization reaction, while R The influence of functional groups is relatively small; therefore, in polymerization reactions, R groups with high steric hindrance should be avoided as much as possible. a (such as R containing tert-butyl) a Specifically: for example, propyl propionate R a and R b All are straight-chain alkyl groups with low steric hindrance, which is beneficial for increasing the growth rate; while isobutyl propionate R a For straight chain, R bThe isobutyl group provides moderate steric hindrance to the reaction center, offering a better balance between activity and selectivity. Other monoester compounds with high steric hindrance, however, weaken the regulation of Lewis acids, thus reducing conversion and broadening the distribution; for example, R in propyl tert-butyrate. It is tert-butyl, with three methyl groups (–CH3) attached to the tert-carbon atom, resulting in great steric hindrance, which in turn causes a strong steric hindrance effect on the molecular skeleton or reaction sites attached to it.

[0012] According to an embodiment of the present invention, the initiator is selected from one, two or more of boron trifluoride, boron trichloride, aluminum trichloride, dichloroethylaluminum, titanium tetrachloride, and ferric trichloride.

[0013] According to an embodiment of the present invention, the molar ratio of the main electron donor to the initiator is 0.1 to 1:1, preferably 0.2 to 0.6:1, and more preferably 0.3 to 0.5:1.

[0014] According to an embodiment of the present invention, the molar ratio of the primary electron donor to the secondary electron donor is 5 to 20:1, for example, 6:1, 7:1, 8:1, 9:1, 10:1, or 15:1.

[0015] According to an embodiment of the present invention, the ether-ester bis-complex further includes a solvent. Preferably, the solvent used in the present invention can be any amount known in the art, as long as it is sufficient to obtain the ether-ester bis-complex.

[0016] According to an embodiment of the present invention, the solvent is selected from weakly polar solvents, such as one, two or more of n-hexane, cyclohexane, methylcyclohexane, and n-heptane.

[0017] The present invention also provides a method for preparing the above-mentioned ether-ester bis-complex, the method comprising: mixing a primary electron donor and a secondary electron donor in a solvent under an inert atmosphere to obtain a mixed solution, cooling to a temperature not higher than 0°C, then adding an initiator and stirring the reaction to obtain the ether-ester bis-complex.

[0018] According to an embodiment of the present invention, the inert atmosphere may be an inert gas known in the art, such as nitrogen, and the oxygen content may be below the range known in the art, such as 100 ppm.

[0019] According to embodiments of the present invention, the molar ratio of the main electron donor to the secondary electron donor, and the molar ratio of the main electron donor to the initiator, have the meanings described above.

[0020] According to an embodiment of the present invention, the cooling can be performed using conditions known in the art, and the present invention does not impose any specific limitations.

[0021] According to an embodiment of the present invention, when the initiator is added, it can be added slowly, and the preferred flow rate is 0.001-0.01 mol / min, for example, 0.002 mol / min or 0.005 mol / min.

[0022] According to an embodiment of the present invention, the stirring can be performed using methods known in the art, such as rapid stirring.

[0023] The present invention also provides the application of the above-mentioned ether-ester bis-complex in the preparation of polyisobutylene.

[0024] The present invention also provides a polyisobutylene, which is prepared by the above-mentioned ether-ester bis-complex.

[0025] According to an embodiment of the present invention, the polyisobutylene has high activity. Preferably, the polyisobutylene has a terminal olefin content greater than 90%, more preferably 91-99%, for example 92%, 93%, 94%, 95%, 96%, 97%, 98%, or any two of the above values.

[0026] According to an embodiment of the present invention, the number average molecular weight of the polyisobutylene is greater than 10,000, for example, 20,000, 25,000, 30,000, 35,000, 40,000, 50,000 or any two of the above values.

[0027] According to an embodiment of the present invention, the molecular weight distribution coefficient of the polyisobutylene is not greater than 1.8, preferably 1.2-1.8, for example, 1.2, 1.3, 1.4, 1.5, 1.6, 1.7 or any two of the above values.

[0028] The present invention also provides a polymerization method for the above-mentioned polyisobutylene, the polymerization method comprising: adding isobutylene monomer in the presence of a solvent, and then adding the above-mentioned ether-ester bis-complex to carry out a polymerization reaction to obtain the polyisobutylene.

[0029] According to an embodiment of the present invention, the solvent is cooled to the polymerization temperature before the isobutylene monomer is added.

[0030] According to an embodiment of the present invention, the polymerization temperature is -50℃ to -20℃, preferably -35℃.

[0031] According to an embodiment of the present invention, the ether-ester bis-complex is added to the reaction system in one step.

[0032] According to an embodiment of the present invention, in the reaction system, the concentration of the isobutylene monomer is 30wt% to 60wt%, preferably 35wt%, 40wt%, 45wt%, 50wt%, 55wt%, or any two of the above values.

[0033] According to an embodiment of the present invention, in the reaction system, the concentration of the initiator is 0.0001~0.1 mol / L, preferably 0.005~0.1 mol / L, for example 0.01 mol / L or 0.05 mol / L.

[0034] According to an embodiment of the present invention, the polymerization reaction time is 1-120 minutes, preferably 20-60 minutes, for example 30 minutes, 40 minutes, or 50 minutes.

[0035] According to an embodiment of the present invention, the polymerization reaction is terminated using methods known in the art, such as adding an alcohol solvent. Further, the alcohol solvent is selected from alcohols known in the art, such as methanol.

[0036] According to an embodiment of the present invention, after the reaction is terminated, the reaction solution can be purified to obtain polyisobutylene. Preferably, the purification can be carried out using methods known in the art, such as alkaline washing and / or solvent removal (e.g., desolventizing by vacuum distillation). Exemplarily, alkalinity is specifically achieved using an alkaline solution, such as a 5%-10% aqueous sodium carbonate solution or a 2%-5% aqueous sodium hydroxide solution.

[0037] According to an embodiment of the present invention, after the polymerization reaction is completed, the conversion rate of isobutylene monomer is greater than 95%, for example greater than 97%, or for example 98%, 99%, or any two of the above values.

[0038] The present invention also provides the application of the above-mentioned polyisobutylene in the preparation of high-performance polymers, especially in the fields of gasoline detergents and lubricant additives.

[0039] The beneficial effects of this invention are: (1) This invention provides a composite electron donor system in which a primary electron donor (ether compound) and a secondary electron donor (monoester compound) synergistically complex. The primary electron donor enhances the solubility of the initiator, while the secondary electron donor weakens the Lewis acid strength. By precisely controlling the molar ratio of ether / ester in the composite electron donor system (e.g., 5~20:1), controlling the stability of the complex by the type of halogen in the primary electron donor, and achieving stratified regulation of electron density and synergistic inhibition of chain transfer and termination through spatial configuration design, polyisobutylene can be prepared at high monomer concentrations. The monomer has a high conversion rate, and the polyisobutylene has high activity (high exo-olefin content) and a narrow molecular weight distribution, wherein: the exo-olefin content is ≥90%, the monomer conversion rate is ≥95%, and the molecular weight distribution is narrow (1.2-1.8).

[0040] (2) The present invention achieves the regulation and control of the molecular weight of the polymer by adjusting the molar ratio of ether / ester and the concentration of complexation with Lewis acid; specifically, the ether main ligand promotes the reversibility of the β-H migration reaction by forming stable clusters with Lewis acid (such as AlCl3, EtAlCl2, BF3), thereby increasing the exo-olefin content (≥90%); the monoester auxiliary ligand adjusts the acid strength of the system and reduces the chain transfer probability through the weak coordination of carbonyl oxygen with Lewis acid, significantly improving the molecular weight distribution of polymerization at high monomer concentration (PDI≤1.8).

[0041] (3) This invention provides a new electronic design concept for cationic polymerization systems, which can be widely applied to the industrial production of polyisobutylene and its derivatives. Detailed Implementation

[0042] The technical solution of the present invention will be further described in detail below with reference to specific embodiments. It should be understood that the following embodiments are merely illustrative and explanatory of the present invention, and should not be construed as limiting the scope of protection of the present invention. All technologies implemented based on the above content of the present invention are covered within the scope of protection intended by the present invention.

[0043] Unless otherwise stated, the raw materials and reagents used in the following examples are commercially available products or can be prepared by known methods.

[0044] In the following embodiments, the primary electron donor is referred to as the primary electron donor ether, and the secondary electron donor is referred to as the secondary electron donor ester.

[0045] Example 1: Add 10 mL of n-hexane and the main ether 2,2-dichlorodiethyl ether (1.430 g, 0.010 mol) to a nitrogen-purged complexing reactor. Add the corresponding amount of the secondary ester isobutyl propionate (0.0651 g, 0.0005 mol) at an ester:ether molar ratio of 0.05:1. Cool to 0°C, and then slowly introduce boron trifluoride (1.36 g, 0.02 mol) at a flow rate of 0.002 mol / min. Stir rapidly at 500 rpm and react for 10 minutes to obtain a boron trifluoride-electron donor complex solution for later use.

[0046] Add 900 mL of n-hexane to a polymerization flask and cool to -35°C; then add 560 g of isobutylene liquid (10.0 mol, 48 wt% in the reaction system) and stir thoroughly; finally, add the pre-cooled boron trifluoride and electron donor complex solution in one go to prepare highly reactive polyisobutylene. The reaction is terminated with methanol after 30 minutes. The reaction solution is then washed with alkali and desolventized by vacuum distillation to obtain the target product.

[0047] The alkaline washing procedure for the reaction solution is as follows: A 7% sodium carbonate aqueous solution is used as the alkaline solution. Each time, the volume of alkaline solution used is 1 / 3 of the reaction solution volume. After adding the alkaline solution to the reaction solution, stir at 250 rpm for 15 minutes at 25°C to ensure sufficient contact between the reaction solution and the alkaline solution to neutralize residual Lewis acids and acidic byproducts. After stirring, allow the mixture to stand for 10 minutes until the system separates into layers, discarding the lower aqueous phase. Repeat the above procedure three times until the pH of the upper organic phase stabilizes at 7, completing the alkaline washing process.

[0048] The specific conditions for desolventizing by vacuum distillation are as follows: use a rotary evaporator or a conventional vacuum distillation apparatus, control the distillation temperature at 50℃, maintain the vacuum degree (absolute pressure) at 0.09MPa, and the stirring speed at 200 rpm to promote solvent evaporation. Control the distillation time at 1 hour until no solvent distills out of the condenser of the distillation apparatus and the material in the reaction flask is homogeneous and viscous, then stop the distillation. Cool the reaction flask to room temperature to obtain the target polyisobutylene product.

[0049] The monomer conversion rate, exo-terminated olefin content, number-average molecular weight, and molecular weight distribution coefficient were determined, and the results are shown in Table 1.

[0050] Example 2: The method is basically the same as in Example 1, except that the amount of the auxiliary ester isobutyl propionate added is 0.130 g, 0.001 mol, and the ester:ether molar ratio is 0.1:1.

[0051] Example 3: The method is basically the same as in Example 1, except that the amount of the auxiliary ester isobutyl propionate added is 0.260 g, 0.002 mol, and the ester:ether molar ratio is 0.2:1.

[0052] Comparative Example 1: The method is basically the same as in Example 1, except that the amount of the auxiliary ester isobutyl propionate added is 0.326 g, 0.0025 mol, and the ester:ether molar ratio is 0.25:1.

[0053] Comparative Example 2: The method is basically the same as in Example 1, except that the amount of the auxiliary ester isobutyl propionate added is 0.391 g, 0.003 mol, and the ester:ether molar ratio is 0.3:1.

[0054] Comparative Example 3: It is basically the same as Example 1, except that the auxiliary ester isobutyl propionate is not added, and the ester: ether molar ratio is 0.

[0055] Comparative Example 4: To compare the effects of the present invention with those of the prior art, a control experiment was conducted with reference to the catalytic system of Example 1 in BASF Patent Publication No. CN1206246C. Specifically, the initiator was boron trifluoride (BF3), the co-catalyst was propanol, and the molar ratio was BF3:propanol = 1:1.6, which was consistent with CN1206246C. At the same time, the mass concentration of isobutylene in the liquid organic phase was adjusted to approximately 48% (i.e., equivalent to the concentration in Example 1 of this application), the reaction temperature was -35°C, and the reaction time was 30 minutes. The remaining steps were carried out under the conditions of Example 1 in the CN1206246C specification.

[0056] The polyisobutylene obtained in this comparative example was found to have a monomer conversion rate of 88.5%, a terminal olefin content of 82.3%, a number-average molecular weight of 21,500, and a molecular weight distribution coefficient of 1.9.

[0057] Table 1. Effect of the ratio of primary ether to secondary ester on the properties of highly reactive polyisobutylene

[0058] Example 4: Add 10 mL of n-hexane and the main ether 2,2-difluorodiethyl ether (1.101 g, 0.010 mol) to a nitrogen-purged complexing reactor. Add the corresponding amount of the secondary ester isobutyl propionate (0.1302 g, 0.001 mol) at an ester:ether molar ratio of 0.1:1. Cool to 0°C, then slowly introduce boron trifluoride (1.36 g, 0.02 mol), stir rapidly, and react for 10 minutes to obtain a boron trifluoride-electron donor complex solution for later use.

[0059] Hexane (900 mL) was added to a polymerization flask and cooled to -35°C. Then, isobutylene liquid (560 g, 10.0 mol) was added and stirred thoroughly. Finally, the pre-cooled boron trifluoride and electron donor complex solution was added in one go to prepare highly reactive polyisobutylene. The reaction was terminated with methanol after 30 minutes. The reaction solution was subjected to multiple alkaline washings and vacuum distillation to remove the solvent (alkaline washing and vacuum distillation steps were the same as in Example 1) to obtain the target product. The monomer conversion rate, exo-terminated olefin content, number-average molecular weight, and molecular weight distribution coefficient were determined, and the results are shown in Table 2.

[0060] Example 5: It is basically the same as Example 4, except that the main ether is 2,2-dibromodiethyl ether (2.319 g, 0.010 mol) and the ester:ether molar ratio is 0.1:1.

[0061] Comparative Example 5: It is basically the same as Example 4, except that the main ether is 2,2-diiododiethyl ether (3.259 g, 0.010 mol) and the ester:ether molar ratio is 0.1:1.

[0062] Table 2. Effect of the type of main ether halogen on the properties of highly reactive polyisobutylene

[0063] Example 6: It is basically the same as Example 2, except that: the auxiliary ester is propyl propionate (0.116 g, 0.001 mol), and the ester: ether molar ratio is 0.1:1.

[0064] Comparative Example 6: It is basically the same as Example 2, except that: the auxiliary ester is propyl tert-butyrate (0.144 g, 0.001 mol), and the ester:ether molar ratio is 0.1:1.

[0065] Table 3. Effect of the spatial structure of the secondary esters on the properties of highly reactive polyisobutylene

[0066] Comparative Example 7: Add 10 mL of n-hexane and the secondary ester isobutyl propionate (0.130 g, 0.001 mol) to a complexing reactor that has been fully purged with nitrogen, and cool to 0 °C. Then slowly introduce boron trifluoride (1.36 g, 0.02 mol), stir rapidly, and react for 10 minutes to obtain a solution of boron trifluoride and electron donor complex for later use.

[0067] Hexane (900 mL) and 1.430 g of the main ether 2,2-dichlorodiethyl ether (0.010 mol, ester:ether molar ratio 0.1:1) were added to a polymerization flask and cooled to -35°C. Then, isobutylene liquid (560 g, 10.0 mol) was added and stirred thoroughly. Finally, the pre-cooled boron trifluoride and electron donor complex solution was added in one go to prepare highly reactive polyisobutylene. The reaction was terminated with methanol after 30 minutes. The reaction solution was subjected to multiple alkaline washings and vacuum distillation to remove the solvent (alkaline washing and vacuum distillation steps were the same as in Example 1) to obtain the target product. The monomer conversion rate, exo-terminated olefin content, number-average molecular weight, and molecular weight distribution coefficient were determined, and the results are shown in Table 4.

[0068] Table 4. Effect of the complexation sequence of ether ester and boron trifluoride on the properties of highly reactive polyisobutylene

[0069] From the data above, we can see that: As shown in Examples 1-3, Comparative Examples 1-2, and Table 1, the technical solution provided by this invention can achieve high monomer conversion rates and high polymerization rates for highly reactive polyisobutylene. exo The content of olefin terminal functional groups, especially when the molar ratio of main ether to secondary ester is in the range of 5~20:1, can maintain a high conversion rate (>96%) and further increase the exo-terminal olefin content (≥90%) and narrow the PDI (≤1.8). Within this window, the lactone acts as a weak ligand to slightly regulate the Lewis acid, thereby significantly inhibiting chain transfer and narrowing the molecular weight distribution. According to Comparative Examples 1 and 2, when the molar ratio of main ether to secondary ester is less than 5:1, the secondary ester will dilute the main ligand effect, resulting in a slight decrease in activity / selectivity; when the molar ratio of main ether to secondary ester is greater than 20:1, the regulating effect of the secondary ester is insufficient.

[0070] As can be seen from Examples 1, 3, and 4 and Table 1, compared with conventional electron donor tert-butyl methyl ether, the electron donor provided by the present invention has a qualitative leap in performance, indicating that the synergistic complexation structure of the ether-based main ligand and the monoester-based auxiliary ligand is more conducive to initiating the living polymerization of isobutylene, and achieving dynamic adjustment of Lewis acid strength and balance of chain growth / transfer reaction (as shown in Table 1).

[0071] According to Examples 2, 4, 5 and Comparative Example 5 and Table 2, when the halogen atom in the main ether is replaced by bromine and iodine in sequence from chlorine, the conversion rate, terminal olefin content and molecular weight distribution all show a deterioration trend to varying degrees. This indicates that the increase in halogen radius leads to a decrease in the stability of ether-Lewis acid complexation, thereby weakening the chain growth advantage and exo-double bond selectivity (as shown in Table 2).

[0072] As can be seen from Examples 2, 6, Comparative Example 6, and Table 3, in the ether / ester bis-ligand system of the present invention, the spatial arrangement and steric hindrance of the monoester have a significant impact on the polymerization performance. Specifically, for example, propyl propionate R... a and R b All are straight-chain alkyl groups with low steric hindrance, which is beneficial for increasing the growth rate; while isobutyl propionate R a For straight chain, R b The isobutyl group provides moderate steric hindrance to the reaction center, offering a good balance between reactivity and selectivity. In propyl tert-butyrate, R... As a tert-butyl group, the tert-carbon atom is simultaneously attached to three methyl groups (–CH3), resulting in significant steric hindrance. This creates a strong steric hindrance effect on the molecular skeleton or reaction sites attached to it, weakening the regulatory effect on Lewis acids, thereby reducing conversion and broadening the distribution. Therefore, in linear monoester compounds, R… a The steric hindrance of the functional groups plays a major role in the polymerization reaction, while R The influence of functional groups is relatively small. Based on this principle, the present invention preferably uses esters with moderate steric hindrance or weak multi-point proximity characteristics as auxiliary ligands to simultaneously achieve high conversion rate, high number-average molecular weight and narrow molecular weight distribution coefficient at high monomer concentrations (as shown in Table 3).

[0073] As can be seen from Example 2, Comparative Example 7, and Table 4, the best catalytic activity and selectivity can only be achieved when the main ether and the secondary ester synergistically complex with boron trifluoride. If any single component is preferentially complexed, the terminal olefin content will decrease and the PDI will increase due to the imbalance of the coordination mode, which further verifies the core mechanism of "coordination synergy" proposed in this invention (as shown in Table 4).

[0074] The exemplary embodiments of the present invention have been described above. However, the scope of protection of this application is not limited to the above embodiments. Any modifications, equivalent substitutions, improvements, etc., made by those skilled in the art within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. An ether-ester bis-complex, characterized in that, The ether-ester bis-complex comprises a primary electron donor, a secondary electron donor, and an initiator; wherein... The primary electron donor is selected from ether compounds; the ether compounds have the general structural formula shown in Formula I below: Equation I In Formula I, X is selected from F, Cl, or Br; p is selected from integers from 0 to 15; R 1 Selected from unsubstituted or by one, two or more selected from R c The following groups are substituted by the following groups: C1–C5 alkyl, C2–C5 alkenyl, C6–C 10 One of the aryl groups (such as phenyl); R c Selected from F, Cl, Br or C1–C3 alkyl groups; The secondary electron donor is selected from monoester compounds; the general formula of the monoester compound is R. a –C(=O)–O–R b , where R a Selected from C1–C5 straight-chain alkyl groups; R b It is selected from C1–C5 straight-chain alkyl, C1–C5 branched alkyl or C1–C5 cycloalkyl, and the C1–C5 branched alkyl does not contain tertiary carbon atoms; The initiator is selected from at least one of boron-based initiators, aluminum-based initiators, titanium-based initiators, and iron-based initiators; The molar ratio of the primary electron donor to the secondary electron donor is 5~20:1; The molar ratio of the main electron donor to the initiator is 0.1 to 1:

1.

2. The ether-ester bis-complex according to claim 1, characterized in that, The initiator is selected from one, two or more of boron trifluoride, boron trichloride, aluminum trichloride, dichloroethylaluminum, titanium tetrachloride, and ferric trichloride.

3. The ether-ester bis-complex according to claim 1, characterized in that, The ether-ester bis-complex further includes a solvent; The solvent is selected from one, two or more of n-hexane, cyclohexane, methylcyclohexane, and n-heptane.

4. The ether-ester bis-complex according to claim 3, characterized in that, In formula I, R 1 Selected from C1–C3 alkyl groups substituted with F, Cl, or Br, or C2–C3 alkenyl groups substituted with halogens; In the general formula of the monoester compounds, R b Selected from C1–C 12 Straight-chain alkyl or branched-chain alkyl.

5. The method for preparing the ether-ester bis-complex according to any one of claims 1-4, characterized in that, The preparation method includes: mixing the main electron donor and the secondary electron donor in an inert atmosphere under solvent conditions to obtain a mixed solution, cooling it to no higher than 0°C, then adding an initiator, and stirring the reaction to obtain the ether-ester bis-complex.

6. The use of the ether-ester bis-complex according to any one of claims 1-4 in the preparation of polyisobutylene.

7. A method for polymerizing polyisobutylene, characterized in that, The polymerization method includes: adding isobutylene monomer in the presence of a solvent, and then adding the ether-ester bis-complex of any one of claims 1-4 to carry out a polymerization reaction to obtain the polyisobutylene.

8. The polymerization method according to claim 7, characterized in that, The polyisobutylene exhibits high activity; the terminal olefin content of the polyisobutylene is greater than 90%. The number-average molecular weight of the polyisobutylene is greater than 10,000; The molecular weight distribution coefficient of the polyisobutylene is not greater than 1.

8.

9. The polymerization method according to claim 7, characterized in that, The solvent is cooled to the polymerization temperature before the isobutylene monomer is added; The polymerization temperature is -50℃ to -20℃; The ether-ester dual complex was added to the reaction system in one step.

10. The polymerization method according to claim 6, characterized in that, In the reaction system, the concentration of the isobutylene monomer is 30wt%~60wt%; In the reaction system, the concentration of the initiator is 0.0001~0.1 mol / L; The polymerization reaction takes 1-120 minutes; After the polymerization reaction is completed, the conversion rate of isobutylene monomer is greater than 95%.

Images