Polar 3,4-isoprene rubber with self-repairing function and preparation method thereof

Abstract

The application relates to a polar 3,4-isoprene rubber with a self-repairing function and a preparation method thereof, and the structural general formula is as follows: wherein E represents O or S; R represents a substituent group on a benzene ring, is hydrogen, a C1-C20 alkyl group, a C6-C20 aryl group, a C1-C20 halogen-containing alkyl group or a halogen substituent group; m represents the number of the substituent group R and is selected from integers from 1 to 5, when m is greater than or equal to 2, the R are the same or different; the ratio of x to y is in the range of 0.1-1000; and the value of n is 30-10000. The content of 3,4-structural units in the polar 3,4-isoprene rubber is not less than 85%; the insertion rate of the polar alpha-olefin in the polar 3,4-isoprene rubber copolymer can be arbitrarily adjusted according to the feeding ratio of monomers, the introduction of oxygen or sulfur groups can increase the polarity of the copolymer, thereby increasing the blending performance of the polar 3,4-isoprene rubber and other polymers, and the copolymer also has excellent self-repairing function.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of polymer preparation, and particularly relates to a polar 3,4-isoprene rubber with self-repairing function and a preparation method thereof. BACKGROUND

[0002] 3,4-isoprene rubber has good wet skid resistance and low sliding resistance due to low double bond content in the main chain and a large number of side chains on the molecular chain. The tread rubber prepared from 3,4-isoprene rubber has excellent wet skid resistance and no serious heat generation phenomenon of styrene-butadiene rubber, which can improve the safety performance of tire driving. Therefore, 3,4-isoprene rubber is an ideal material for preparing high-performance tire tread rubber, and it can also be used as sealing material, shock-resistant material and polypropylene toughening modifier, so it is highly concerned.

[0003] However, 3,4-isoprene rubber lacks polar groups, and its blending performance is poor when mixed with fillers such as carbon black. People have studied functionalized 3,4-isoprene rubber. For example, Diao Kaiying et al. realized the copolymerization of polar styrene isoprene by using a single-metallocene scandium catalytic system, and the 3,4-selectivity of isoprene structural units in the copolymer was 70% (Diao Kaiying. Copolymerization of styrene derivatives and conjugated dienes by single-metallocene scandium catalytic system [D]). In 2020, Sun Mengting et al. realized the copolymerization of isoprene and amine-functionalized pentene by using a single-metallocene scandium catalytic system, and the 3,4-selectivity of isoprene structural units in the copolymer was 60-70% (Sun Mengting. Study on copolymerization of functionalized alpha-olefin and isoprene by single-metallocene scandium catalytic system [D]). However, the selectivity of 3,4-isoprene rubber obtained by the above work is low. Therefore, it is urgent to develop a new catalytic system to obtain polar 3,4-isoprene rubber with high 3,4-selectivity.

[0004] If 3,4-isoprene rubber has self-healing property, it will improve the service life, safety and environmental impact of tire rubber. The ultimate goal is to create a tough and autonomous self-repairing polymer that can spontaneously repair mechanical damage in a highly variable real-world environment without external intervention. Most of the self-repairing polymers reported in previous literature rely on reversible chemical interactions, such as Diels-Alder reaction, hydrogen bonding, ion pair formation and metal-ligand interaction. Such self-repairing polymers based on chemical interactions usually require complex molecular design and tedious multi-step synthesis, and usually require input of external energy or stimuli (such as heat, light or pressure) to achieve significant repair after mechanical damage. In addition, the chemical interactions used for self-repairing mechanism (such as hydrogen bonding, ion pair interaction and metal-ligand interaction) may be destroyed under certain chemical environment (such as acidic or basic conditions), which may affect the self-repairing performance. SUMMARY

[0005] This invention addresses the technical problems in the prior art by providing a self-healing polar 3,4-isoprene rubber and its preparation method. The insertion rate of the polar α-olefin in the 3,4-isoprene rubber copolymer of this invention can be arbitrarily adjusted according to the monomer feed ratio. Simultaneously, the introduction of oxygen- or sulfur-containing groups can increase the polarity of the copolymer, thereby enhancing the blending properties of 3,4-isoprene rubber with other polymers. Furthermore, the 3,4-isoprene rubber copolymer of this invention also possesses excellent self-healing properties.

[0006] To solve the above-mentioned technical problems, the technical solution of the present invention is as follows:

[0007] A polar 3,4-isoprene gum with self-healing function has the structure shown in general formula (I):

[0008]

[0009] In equation (Ⅰ), E represents O or S;

[0010] R represents a substituent on the benzene ring, which can be hydrogen, C1-C20 alkyl, C6-C20 aryl, C1-C20 halogen-containing alkyl, or halogen substituent; m represents the number of substituents R, which is an integer selected from 1 to 5. When m≥2, R can be the same or different.

[0011] The x, y ratio can take any value within the range of 0.1 to 1000;

[0012] The number-average molecular weight of the polar 3,4-isoprene gum is 1×10⁻⁶. 4 ~250×10 4 The value of n is 30 to 10000.

[0013] In the above technical solution, the content of 3,4-structural units in the polar 3,4-isoprene gum is not less than 85%; the insertion rate of polar α-olefin structural units in the structure can be arbitrarily adjusted between 0.1% and 90%.

[0014] A method for preparing a self-healing polar 3,4-isoprene gum includes the following steps:

[0015] a) Under the protection of inert gases nitrogen or argon, the amidine-based rare earth catalyst is dispersed in an organic solvent to obtain a rare earth catalyst solution.

[0016] b) Using isoprene and polar α-olefin as monomer raw materials, the rare earth catalyst solution obtained in step a) is used to catalyze the polymerization reaction. After a certain polymerization time, the polymerization reaction is terminated, the product is precipitated and dried to obtain polar 3,4-isoprene gum.

[0017] The structural formula of polar α-olefin monomers is shown in general formula (Ⅲ):

[0018]

[0019] In the formula, E represents O or S;

[0020] R represents a substituent on the benzene ring, which can be hydrogen, C1-C20 alkyl, C6-C20 aryl, C1-C20 alkyl containing halogen, or a halogen substituent; m represents the number of substituents R, which is an integer selected from 1 to 5. When m≥2, R can be the same or different.

[0021] In the above technical solution, the polar α-olefin monomer is selected from one of the AW structures:

[0022]

[0023]

[0024] In the above technical solution, the rare earth catalyst is composed of three parts: A, B, and C. Among them, A is a rare earth complex, which is the complex shown in formula (II).

[0025]

[0026] In formula (II), R1 is a substituent of the amidine carbon, which is a C1-C20 aryl, a C1-C20 halogenated aryl, a C1-C20 alkyl, or a C1-C20 halogenated alkyl.

[0027] R2 and R3 are substituents on the nitrogen atom, and each is independently a C1-C20 aryl, a C1-C20 halogenated aryl, a C1-C20 alkyl, or a C1-C20 halogenated alkyl.

[0028] The rare earth metal Ln is selected from Sc, Y, La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb or Lu;

[0029] R4 and R5 are each independently C1-C10 alkyl, C1-C10 silyl, C1-C10 silamido, C1-C10 alkylamido, or C3-C10 allyl.

[0030] L represents tetrahydrofuran, diethyl ether, ethylene glycol dimethyl ether, or toluene; m represents 0, 1, or 2.

[0031] B is an organoboron reagent selected from [Ph3C][B(C6F5)4], [PhNMe2H][BPh4], [NEt3H][BPh4], [PhNMe2H][B(C6F5)4], or B(C6F5)3;

[0032] C represents an alkylaluminum compound, selected from alkylaluminum or aluminumoxane.

[0033] In the above technical solution, R1 is phenyl, p-methylphenyl, p-ethylphenyl, p-isopropylphenyl, p-tert-butylphenyl, benzyl, m-methylphenyl, m-ethylphenyl, m-isopropylphenyl, mestrimethylphenyl, 2,6-dimethylphenyl, 2,6-diethylphenyl, mestriethylphenyl or 2,6-diisopropylphenyl.

[0034] R2 and R3 are each independently phenyl, p-methylphenyl, p-ethylphenyl, p-isopropylphenyl, p-tert-butylphenyl, benzyl, m-methylphenyl, m-ethylphenyl, m-isopropylphenyl, mesitylene, mesitylene, mesitylene, mesitylene, mesitylene, 2,6-dimethylphenyl, 2,6-diethylphenyl, 2,6-diisopropylphenyl, 2,6-diethyl-4-methylphenyl, 2,6-diethyl-4-tert-butylphenyl, 2,6-diisopropyl-4-methylphenyl, 2,6-ditert-butyl-4-methylphenyl, 2,6-diphenylphenyl, 2,6-ditrifluoromethylphenyl, 2-fluorophenyl, 3-trifluoromethylphenyl, p-trifluoromethylphenyl, or p-fluorophenyl.

[0035] R4 and R5 are each independently CH3, CH2SiMe3, CH(SiMe3)2, N(SiMe3)2, NH(SiMe3) or 1,3-C3H5;

[0036] B is either [Ph3C][B(C6F5)4] or [PhNMe2H][B(C6F5)4];

[0037] C represents trimethylaluminum, triethylaluminum, tri-n-propylaluminum, tri-n-butylaluminum, triisopropylaluminum, triisobutylaluminum, tripentylaluminum, trihexylaluminum, tricyclohexylaluminum, trioctylaluminum, triphenylaluminum, tri-p-tolylaluminum, tribenzylaluminum, ethyl dibenzylaluminum, ethyl di-p-tolylaluminum, diethylbenzylaluminum, dimethylaluminum hydride, diethylaluminum hydride, di-n-propylaluminum hydride, di-n-butylaluminum hydride, diisopropylaluminum hydride, diisobutylaluminum hydride, dipentylaluminum hydride, dihexylaluminum hydride, dicyclohexylaluminum hydride, dioctylaluminum hydride, diphenylaluminum hydride, and di-p-tolylaluminum hydride. One or more of the following: tolyl aluminum hydride, dibenzyl aluminum hydride, ethylbenzyl aluminum hydride, ethyl-p-tolyl aluminum hydride, dimethyl aluminum chloride, diethyl aluminum chloride, di-n-propyl aluminum chloride, di-n-butyl aluminum chloride, diisopropyl aluminum chloride, diisobutyl aluminum chloride, dipentyl aluminum chloride, dihexyl aluminum chloride, dicyclohexyl aluminum chloride, dioctyl aluminum chloride, diphenyl aluminum chloride, di-p-tolyl aluminum chloride, dibenzyl aluminum chloride, ethylbenzyl aluminum chloride, ethyl-p-tolyl aluminum chloride, methylaluminoxane, ethylaluminoxane, n-propylaluminoxane, and n-butylaluminoxane.

[0038] In the above technical solution, the organic solvent is selected from one or a mixture of several of saturated alkanes, aromatics, halogenated aromatics, and cycloalkanes.

[0039] In the above technical solution, the organic solvent is selected from one or a mixture of several of toluene, xylene, benzene, n-hexane, n-heptane, cyclohexane, chlorobenzene, dichlorobenzene, and trichlorobenzene.

[0040] In the above technical solution, the molar ratio of the polar α-olefin monomer to the rare earth complex having the structure of formula (II) is (50-10000):1; the molar ratio of the isoprene monomer to the rare earth complex having the structure of formula (II) is (50-10000):1; the molar ratio of the organoboron salt to the rare earth complex having the structure of formula (II) is (0.5-2.0):1; and the molar ratio of the alkylaluminum compound to the rare earth complex having the structure of formula (II) is (0.5-3000):1.

[0041] In the above technical solution, the polymerization reaction temperature is -60 to 80°C, and the polymerization reaction time is 0.5 to 48 hours.

[0042] The beneficial effects of this invention are:

[0043] The polar α-olefin insertion rate in the self-healing polar 3,4-isoprene rubber copolymer of the present invention can be arbitrarily adjusted according to the monomer feed ratio. Simultaneously, the introduction of oxygen- or sulfur-containing groups can increase the polarity of the copolymer, thereby enhancing the blending performance of 3,4-isoprene rubber with other polymers. Furthermore, the 3,4-isoprene rubber copolymer of the present invention also possesses excellent self-healing properties.

[0044] The preparation method of the self-healing polar 3,4-isopentyl gum of the present invention uses a catalyst combination of rare earth complexes, alkyl aluminum compounds and organoboron salts. This invention is the first to utilize amidine-based rare earth catalysts to synthesize oxygen- or sulfur-containing polar 3,4-isopentyl gum, and the insertion rate of polar α-olefin structural units in the copolymer can be arbitrarily controlled between 1% and 99%, breaking through the previous limitation of low insertion rate of functionalized monomers in copolymers. Furthermore, the polymer has excellent self-healing function. Therefore, the preparation method of polar 3,4-isopentyl gum provided by the present invention is highly innovative. Attached Figure Description

[0045] The present invention will now be described in further detail with reference to the accompanying drawings and specific embodiments.

[0046] Figure 1 This is the NMR spectrum of the polar 3,4-isoprene gum obtained in Preparation Example 6 of the present invention.

[0047] Figure 2This is a GPC characterization diagram of the polar 3,4-isoprene gum obtained in Preparation Example 6 of the present invention.

[0048] Figure 3 This is a schematic diagram illustrating the self-healing ability of the polar 3,4-isoprene gum with self-healing function of the present invention.

[0049] Figure 4 This is a self-healing tensile curve of the polar 3,4-isoprene gum obtained in Preparation Example 1 of the present invention. Detailed Implementation

[0050] The self-healing polar 3,4-isoprene gum of the present invention has a structure of general formula (I):

[0051]

[0052]

[0053] In the formula, E represents O or S; R represents a substituent on the benzene ring, which is hydrogen, C1-C20 alkyl, C6-C20 aryl, C1-C20 halogen-containing alkyl or halogen substituent; m represents the number of substituents R, which is an integer selected from 1 to 5. When m≥2, R are the same or different.

[0054] The x, y ratio can take any value within the range of 0.1 to 1000;

[0055] The self-healing polar 3,4-isopentyl gum of the present invention also has the following characteristics: the number average molecular weight of the polar 3,4-isopentyl gum is 1×10⁻⁶. 4 ~250×10 4 The value of n is 30 to 10000. The content of 3,4-structural units in the polar 3,4-isoprene gum is not less than 85%. The insertion rate of polar α-olefin structural units in the copolymer can be arbitrarily adjusted between 0.1% and 90%.

[0056] The preparation method of the self-healing polar 3,4-isopentyl gum of the present invention includes the following steps:

[0057] a) Under the protection of inert gases nitrogen or argon, the amidine-based rare earth catalyst is dispersed in an organic solvent to obtain a catalyst solution;

[0058] b) Using polar α-olefins and isoprene as monomer raw materials, and according to a certain monomer feed ratio, a catalyst solution obtained in step a) is used to catalyze the polymerization reaction. After a certain polymerization time, the polymerization reaction is terminated, the product is precipitated, and dried to obtain polar 3,4-isoprene gum with self-healing function. The polymerization reaction can be carried out in the presence of solvent in solution polymerization or in the absence of solvent in bulk polymerization.

[0059] The polar α-olefin monomer has the structure of general formula (Ⅲ):

[0060]

[0061] In the formula, E represents O or S; R represents a substituent on the benzene ring, which is hydrogen, C1-C20 alkyl, C6-C20 aryl, C1-C20 halogen-containing alkyl or halogen substituent; m represents the number of substituents R, which is an integer selected from 1 to 5. When m≥2, R are the same or different.

[0062] Preferably, the polar α-olefin monomer is one of the structures shown in A to W:

[0063]

[0064] The rare earth catalyst of this invention consists of three parts: A, B, and C.

[0065] Wherein, A is a rare earth complex, which is the complex shown in formula (II):

[0066]

[0067] In general formula (II), R1 is a substituent of the amidine carbon, which is a C1-C20 aryl, a C1-C20 halogenated aryl, a C1-C20 alkyl, or a C1-C20 halogenated alkyl, preferably phenyl, p-methylphenyl, p-ethylphenyl, p-isopropylphenyl, p-tert-butylphenyl, benzyl, m-methylphenyl, m-ethylphenyl, m-isopropylphenyl, mestrimethylphenyl, 2,6-dimethylphenyl, 2,6-diethylphenyl, mestriethylphenyl, or 2,6-diisopropylphenyl.

[0068] R2 and R3 are substituents on the nitrogen atom, each independently being a C1-C20 aryl, a C1-C20 halogenated aryl, a C1-C20 alkyl, or a C1-C20 halogenated alkyl, preferably phenyl, p-methylphenyl, p-ethylphenyl, p-isopropylphenyl, p-tert-butylphenyl, benzyl, m-methylphenyl, m-ethylphenyl, m-isopropylphenyl, mesitylene, mesitylene, mesitylene, mesitylene, mesitylene, 2,6-dimethylphenyl, 2,6-diethylphenyl, 2,6-diisopropylphenyl, 2,6-diethyl-4-methylphenyl, 2,6-diethyl-4-tert-butylphenyl, 2,6-diisopropyl-4-methylphenyl, 2,6-ditert-butyl-4-methylphenyl, 2,6-diphenylphenyl, 2,6-ditrifluoromethylphenyl, 2-fluorophenyl, 3-trifluoromethylphenyl, p-trifluoromethylphenyl, or p-fluorophenyl.

[0069] The rare earth metal Ln is selected from Sc, Y, La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb or Lu;

[0070] R4 and R5 are each independently selected from C1-C10 alkyl, C1-C10 silyl, C1-C10 silamido, C1-C10 alkylamido or C3-C10 allyl, preferably CH3, CH2SiMe3, CH(SiMe3)2, N(SiMe3)2, NH(SiMe3) or 1,3-C3H5.

[0071] L is tetrahydrofuran, diethyl ether, ethylene glycol dimethyl ether, or toluene; m = 0, 1, or 2.

[0072] B is an organoboron reagent selected from [Ph3C][B(C6F5)4], [PhNMe2H][BPh4], [NEt3H][BPh4], [PhNMe2H][B(C6F5)4] or B(C6F5)3, preferably [Ph3C][B(C6F5)4] or [PhNMe2H][B(C6F5)4].

[0073] The molar ratio of the organic boron salt to the rare earth complex having the structure of formula (II) is (0.5 to 2.0): 1.

[0074] C is an alkylaluminum compound, selected from: alkylaluminum or aluminum oxane; further preferably, the alkylaluminum is a hydride alkylaluminum or an alkylaluminum chloride, and even more preferably, the alkylaluminum compound is trimethylaluminum, triethylaluminum, tri-n-propylaluminum, tri-n-butylaluminum, triisopropylaluminum, triisobutylaluminum, tripentylaluminum, trihexylaluminum, tricyclohexylaluminum, trioctylaluminum, triphenylaluminum, tri-p-tolylaluminum, tribenzylaluminum, ethyl dibenzylaluminum, ethyl di-p-tolylaluminum, diethylbenzylaluminum, dimethylaluminum hydride, diethylaluminum hydride, di-n-propylaluminum hydride, di-n-butylaluminum hydride, diisopropylaluminum hydride, diisobutylaluminum hydride, dipentylaluminum hydride. The following are some of the following: dihexylaluminum hydride, dicyclohexylaluminum hydride, dioctylaluminum hydride, diphenylaluminum hydride, di-p-tolylaluminum hydride, dibenzylaluminum hydride, ethylbenzylaluminum hydride, ethyl-p-tolylaluminum hydride, dimethylaluminum chloride, diethylaluminum chloride, di-n-propylaluminum chloride, di-n-butylaluminum chloride, diisopropylaluminum chloride, diisobutylaluminum chloride, dipentylaluminum chloride, dihexylaluminum chloride, dicyclohexylaluminum chloride, dioctylaluminum chloride, diphenylaluminum chloride, di-p-tolylaluminum chloride, dibenzylaluminum chloride, ethylbenzylaluminum chloride, ethyl-p-tolylaluminum chloride, methylaluminoxane, ethylaluminoxane, n-propylaluminoxane, and n-butylaluminoxane.

[0075] The molar ratio of the alkylaluminum compound to the rare earth complex having the structure of formula II is (0.5–3000):1.

[0076] When solution polymerization is used, the organic solvent is selected from one or a mixture of several saturated alkanes, aromatics, halogenated aromatics, and cycloalkanes. Preferably, it is selected from one or a mixture of several toluene, xylene, benzene, n-hexane, n-heptane, cyclohexane, chlorobenzene, dichlorobenzene, and trichlorobenzene.

[0077] The molar ratio of the polar α-olefin monomer to the rare earth complex having the structure of formula (II) is (50-10000):1; the molar ratio of the isoprene monomer to the rare earth complex having the structure of formula (II) is (50-10000):1; the feed ratio of the polar α-olefin monomer to the isoprene monomer can be adjusted arbitrarily.

[0078] The concentration of the polar α-olefin monomer is 1–60 g / 100 mL; the concentration of the isoprene monomer is 1–60 g / 100 mL.

[0079] The polymerization reaction is carried out at a temperature of -60 to 80°C for 0.5 to 48 hours.

[0080] A specific embodiment of the preparation method of the self-healing polar 3,4-isoprene gum of the present invention is as follows:

[0081] A solution of the coordination catalytic system composed of the rare earth complex, alkyl aluminum compound, and organoboron salt was placed in a polymerization container that had been treated to be anhydrous and oxygen-free. Simultaneously, polar α-olefin monomers and isoprene monomers were added. The molar ratio of the added polar α-olefin monomer to the rare earth complex in the coordination catalytic system was 50:1 to 10000:1, and the molar ratio of the added isoprene monomer to the rare earth complex in the coordination catalytic system was also 50:1 to 10000:1. The feed ratio of the polar α-olefin monomer to the isoprene monomer could be adjusted arbitrarily. The polymerization reaction was carried out at -60 to 80°C for 0.5 to 48 hours. A 10% (v / v) hydrochloric acid-ethanol solution was added to terminate the polymerization reaction. The reaction solution was poured into methanol to settle, yielding polar 3,4-isoprene gum. The obtained polymer was then dried in a vacuum drying oven to obtain polar 3,4-isoprene gum with constant weight.

[0082] To further understand the present invention, preferred embodiments of the present invention are described below in conjunction with examples. However, it should be understood that these descriptions are only for further illustrating the features and advantages of the present invention and are not intended to limit the scope of the claims of the present invention.

[0083] According to the present invention, the rare earth catalyst comprises a rare earth complex, an alkylaluminum compound, and an organoboron salt; the catalyst is a coordination catalytic system containing multiple compounds. The rare earth complex used in the following examples is a complex of formula (II), wherein the rare earth complex having the structure of formula (II) is preferably a complex of formulas 1 to 15.

[0084]

[0085]

[0086] According to the present invention, the catalyst is prepared by mixing a rare earth complex, an alkyl aluminum compound, and an organoboron salt in an organic solvent according to a specified ratio to obtain a homogeneous catalyst. The organic solvent is selected from one or a mixture of several saturated alkanes, aromatics, halogenated aromatics, and cycloalkanes. Preferred organic solvents include toluene, xylene, benzene, n-hexane, n-heptane, cyclohexane, chlorobenzene, dichlorobenzene, and trichlorobenzene.

[0087] Examples of catalyst combination preparation:

[0088] Preparation of catalyst combination 1: At 25°C, 10 μmol of the rare earth complex shown in Formula 1, 10 μmol of [Ph3C][B(C6F5)4], 100 μmol of triisobutylaluminum, and 5 mL of toluene solvent were added to a 25 mL polymerization container that had been treated with anhydrous and oxygen-free methods. The concentration of the rare earth complex in the catalyst combination was 2.0 mmol·L⁻¹. –1 The reaction was carried out for 2 minutes to obtain catalyst combination 1.

[0089] Preparation of catalyst combination 2: At 25°C, 10 μmol of the rare earth complex shown in Formula 2, 10 μmol of [Ph3C][B(C6F5)4], 100 μmol of triisobutylaluminum, and 5 mL of toluene solvent were added to a 25 mL polymerization container that had been treated with anhydrous and oxygen-free methods. The concentration of the rare earth complex in the catalyst combination was 0.67 mmol·L⁻¹. –1 After reacting for 2 minutes, catalyst combination 2 was obtained.

[0090] Preparation of catalyst combination 3: At 0°C, 10 μmol of the rare earth complex shown in Formula 2, 10 μmol of [Ph3C][B(C6F5)4], 100 μmol of triisobutylaluminum, and 5 mL of toluene solvent were added to a 25 mL polymerization container that had been treated with anhydrous and oxygen-free methods. The concentration of the rare earth complex in the catalyst combination was 0.67 mmol·L⁻¹. –1 After reacting for 2 minutes, catalyst combination 3 was obtained.

[0091] Preparation of catalyst combination 4: At -60℃, 10 μmol of the rare earth complex shown in Formula 2, 10 μmol of [Ph3C][B(C6F5)4], 100 μmol of triisobutylaluminum, and 5 mL of toluene solvent were added to a 25 mL polymerization container that had been treated with anhydrous and oxygen-free solvent. The concentration of the rare earth complex in the catalyst combination was 0.67 mmol·L⁻¹. –1 After reacting for 2 minutes, catalyst combination 4 was obtained.

[0092] Preparation of catalyst combination 5: At 40°C, 10 μmol of the rare earth complex shown in Formula 2, 10 μmol of [Ph3C][B(C6F5)4], 100 μmol of triisobutylaluminum, and 5 mL of toluene solvent were added to a 25 mL polymerization container that had been treated with anhydrous and oxygen-free methods. The concentration of the rare earth complex in the catalyst combination was 0.67 mmol·L⁻¹. –1 After reacting for 2 minutes, catalyst combination 5 was obtained.

[0093] Preparation of catalyst combination 6: At 80°C, 10 μmol of the rare earth complex shown in Formula 2, 10 μmol of [Ph3C][B(C6F5)4], 100 μmol of triisobutylaluminum, and 5 mL of toluene solvent were added to a 25 mL polymerization container that had been treated with anhydrous and oxygen-free methods. The concentration of the rare earth complex in the catalyst combination was 0.67 mmol·L⁻¹. –1 After reacting for 2 minutes, catalyst combination 6 was obtained.

[0094] Preparation of catalyst combination 7: At 25°C, 10 μmol of the rare earth complex shown in Formula 3, 10 μmol of [PhNHMe2][B(C6F5)4], 200 μmol of triethylaluminum, and 10 mL of hexane solvent were added to a 25 mL polymerization container that had been treated with anhydrous and oxygen-free methods. The concentration of the rare earth complex in the catalyst combination was 1.0 mmol·L⁻¹. –1 After reacting for 2 minutes, catalyst combination 7 was obtained.

[0095] Preparation of catalyst combination 8: At -40℃, 10 μmol of the rare earth complex shown in Formula 4, 10 μmol of [Ph3C][B(C6F5)4], 100 μmol of triisobutylaluminum, and 10 mL of toluene solvent were added to a 50 mL polymerization container that had been treated with anhydrous and oxygen-free methods. The concentration of the rare earth complex in the catalyst combination was 1.0 mmol·L⁻¹. –1 After reacting for 2 minutes, catalyst combination 8 was obtained.

[0096] Preparation of catalyst combination 9: At 25°C, 10 μmol of the rare earth complex shown in Formula 5, 10 μmol of [Ph3C][B(C6F5)4], 100 μmol of triisobutylaluminum, and 10 mL of pentane solvent were added to a 50 mL polymerization container that had been treated with anhydrous and oxygen-free methods. The concentration of the rare earth complex in the catalyst combination was 0.5 mmol·L⁻¹. –1 After reacting for 2 minutes, catalyst combination 9 was obtained.

[0097] Preparation of catalyst combination 10: At 60 °C, 10 μmol of the rare earth complex shown in Formula 6, 10 μmol of [PhNHMe2][B(C6F5)4], 1 mmol of triisobutylaluminum, and 10 mL of xylene solvent were added to a 25 mL polymerization container that had been treated with anhydrous and oxygen-free methods. The concentration of the rare earth complex in the catalyst combination was 1.0 mmol·L⁻¹. –1 The reaction was carried out for 2 minutes to obtain catalyst combination 10.

[0098] Preparation of catalyst combination 11: At 25°C, 10 μmol of the rare earth complex shown in Formula 7, 10 μmol of [Ph3C][BPh4], 10 mmol of triisobutylaluminum, and 5 mL of hexane solvent were added to a 50 mL polymerization container that had been treated with anhydrous and oxygen-free methods. The concentration of the rare earth complex in the catalyst combination was 0.2 mmol·L⁻¹. –1 After reacting for 2 minutes, catalyst combination 11 was obtained.

[0099] Preparation of catalyst combination 12: At 0 °C, 10 μmol of the rare earth complex shown in Formula 8, 20 μmol of [PhNHMe2][BPh4], 5 mmol of triisobutylaluminum, and 5 mL of hexane solvent were added to a 50 mL polymerization container that had been treated with anhydrous and oxygen-free methods. The concentration of the rare earth complex in the catalyst combination was 0.25 mmol·L⁻¹. –1 After reacting for 2 minutes, catalyst combination 12 was obtained.

[0100] Preparation of catalyst combination 13: At 80°C, 10 μmol of the rare earth complex shown in Formula 9, 10 μmol of B(C6F5)3, 100 μmol of triisobutylaluminum, and 5 mL of hexane solvent were added to a 50 mL polymerization container that had been treated with anhydrous and oxygen-free methods. The concentration of the rare earth complex in the catalyst combination was 0.2 mmol·L⁻¹. –1 After reacting for 2 minutes, catalyst combination 13 was obtained.

[0101] Preparation of catalyst combination 14: At 0 °C, 10 μmol of the rare earth complex shown in Formula 10, 10 μmol of [Ph3C][B(C6F5)4], 500 μmol of triisobutylaluminum, and 5 mL of xylene solvent were added to a 50 mL polymerization container that had been treated with anhydrous and oxygen-free methods. The concentration of the rare earth complex in the catalyst combination was 0.25 mmol·L⁻¹. –1 After reacting for 2 minutes, catalyst combination 14 was obtained.

[0102] Preparation of catalyst combination 15: At 40°C, 10 μmol of the rare earth complex shown in Formula 11, 10 μmol of [PhNHMe2][B(C6F5)4], 100 μmol of trimethylaluminum, and 10 mL of toluene solvent were added to a 50 mL polymerization container that had been treated with anhydrous and oxygen-free methods. The concentration of the rare earth complex in the catalyst combination was 0.33 mmol·L⁻¹. –1 The reaction was carried out for 2 minutes to obtain catalyst combination 15.

[0103] Preparation of catalyst combination 16: At 25°C, 10 μmol of the rare earth complex shown in Formula 12, 10 μmol of [NEt3H][BPh4], 100 μmol of trimethylaluminum, and 10 mL of xylene solvent were added to a 25 mL polymerization container that had been treated with anhydrous and oxygen-free methods. The concentration of the rare earth complex in the catalyst combination was 0.25 mmol·L⁻¹. –1 The reaction was carried out for 2 minutes to obtain catalyst combination 16.

[0104] Preparation of catalyst combination 17: At –60°C, 10 μmol of the rare earth complex shown in Formula 13, 10 μmol of [Ph3C][BPh4], 100 μmol of triisobutylaluminum, and 5 mL of hexane solvent were added to a 50 mL polymerization container that had been treated with anhydrous and oxygen-free methods. The concentration of the rare earth complex in the catalyst combination was 0.25 mmol·L⁻¹. –1 After reacting for 2 minutes, catalyst combination 17 was obtained.

[0105] Preparation of catalyst combination 18: At 80 °C, 10 μmol of the rare earth complex shown in Formula 14, 10 μmol of [Ph3C][BPh4], 30 mmol of methylaluminoxane, and 5 mL of toluene solvent were added to a 100 mL polymerization container that had been treated to be anhydrous and oxygen-free. The concentration of the rare earth complex in the catalyst combination was 0.2 mmol·L⁻¹. –1 After reacting for 2 minutes, catalyst combination 18 was obtained.

[0106] Preparation of catalyst combination 19: At 0 °C, 10 μmol of the rare earth complex shown in Formula 15, 10 μmol of [Ph3C][B(C6F5)4], 20 μmol of diisobutylaluminum hydride, and 5 mL of chlorobenzene solvent were added to a 50 mL polymerization container that had been treated with anhydrous and oxygen-free methods. The concentration of the rare earth complex in the catalyst combination was 0.2 mmol·L⁻¹. –1 After reacting for 2 minutes, catalyst combination 19 was obtained.

[0107] Preparation of catalyst combination 20: At 25°C, 10 μmol of the rare earth complex shown in Formula 15, 10 μmol of [Ph3C][B(C6F5)4], 100 μmol of methylaluminoxane, and 10 mL of chlorobenzene solvent were added to a 50 mL polymerization container that had been treated with anhydrous and oxygen-free methods. The concentration of the rare earth complex in the catalyst combination was 0.2 mmol·L⁻¹. –1 The reaction was carried out for 2 minutes to obtain catalyst combination 20.

[0108] Examples of preparation of self-healing polar 3,4-isoprene gum by copolymerization of polar α-olefins and isoprene:

[0109] Example 1

[0110] 5 mL of toluene solution of catalyst combination 1 was placed in a polymerization flask that had been treated to be anhydrous and oxygen-free. 5.0 mmol of polar α-olefin monomer A and 5.0 mmol of isoprene monomer were added. The polymerization reaction was carried out at 25 °C for 4 hours. The polymerization reaction was terminated by adding 2 mL of 10% hydrochloric acid in ethanol solution. The reaction solution was poured into 100 mL of methanol for precipitation, yielding a phenoxy-functionalized polar 3,4-polyisoprene copolymer. This copolymer was then dried in a vacuum drying oven for 48 hours to obtain phenoxy-functionalized polar 3,4-polyisoprene with a net weight of 1.19 g. The total conversion rate was 95%. The results were analyzed using 1H NMR spectroscopy (NMR spectroscopy). 1 HNMR and carbon NMR (H2NM) 13 ¹³C NMR analysis revealed that the syndiotacticity of the phenoxy-functionalized polar 3,4-polyisoprene was greater than 99%; the insertion rate of the polar α-olefin monomer in the copolymer was 54%; GPC analysis showed that the number-average molecular weight (Mn) of the phenoxy-functionalized polar 3,4-polyisoprene was... n The value is 80,000, and the molecular weight distribution (M) is... w / M n The glass transition temperature (Tg) was 1.48. DSC analysis yielded the glass transition temperature (Tg) of phenoxy-functionalized polar 3,4-polyisoprene. g The temperature is 7℃.

[0111] Example 2-61

[0112] Examples 2–61 are examples of the copolymerization of polar α-olefins and isoprene using the coordination catalysis system provided by the present invention. Figure 1 The NMR spectrum of the polar 3,4-isoprene gum prepared in Example 6 is shown in Table 1. The procedures were the same as in Example 1, and the specific conditions and results are shown in Table 1.

[0113] Table 1. Synthesis of self-healing polar 3,4-isopentyl gum by coordination polymerization method.

[0114]

[0115]

[0116]

[0117] From the polymerization data of Examples 1-61 of the copolymerization of polar α-olefins and isoprene, it can be concluded that when the rare earth catalyst combination provided by this invention catalyzes the copolymerization reaction of polar α-olefins and isoprene using coordination polymerization, the conversion of polar α-olefin monomers and isoprene monomers can reach 71% to 100%. The number average molecular weight of the polar 3,4-isoprene polymer is 1 × 10⁻⁶. 4 ~250×10 4 Within this range, the molecular weight distribution is 1.1–3.0 (see appendix). Figure 2 This rare-earth catalytic combination exhibits high temperature adaptability; within a polymerization temperature range of -60 to 80°C, the insertion rate of polar α-olefin structural units in the copolymer can be arbitrarily adjusted between 0.1% and 90%. However, because the insertion of polar α-olefin monomers into the copolymer is detrimental to polymer crystallization, most of the copolymers lack a melting point.

[0118] Contact angle is an important indicator of polymer polarity; the smaller the contact angle, the greater the polarity of the polymer. We tested the contact angle of the partially polar α-olefin-isoprene copolymer and pure 3,4-isoprene gum. The test results of the contact angle of the partially polar α-olefin-isoprene copolymer are shown in Table 1. The contact angle of pure 3,4-isoprene gum was 100°. Compared with pure 3,4-isoprene gum, the contact angle of the polar α-olefin-isoprene copolymer of the present invention is smaller, and the polarity of the copolymer increases with the increase of the content of polar α-olefin structural units.

[0119] Tensile testing can determine a range of strength and plasticity properties of a material. Strength generally refers to a material's ability to resist elastic deformation, plastic deformation, and fracture under external force. We conducted tensile tests on polar 3,4-isoprene rubber, as shown in the attached figure. Figure 3 As shown in Table 2, the sample was cut, allowed to heal at room temperature for a period of time, and then subjected to a tensile test again. Figure 4The image shows the self-healing tensile curve of the polar 3,4-isoprene gum obtained in Example 1, indicating that the polar 3,4-isoprene gum has good self-healing function.

[0120] Table 2. Tests on the self-healing function of polar 3,4-isoprene gum

[0121]

[0122]

[0123] The preparation method of a self-healing polar 3,4-isoprene gum provided by the present invention has been described in detail above. Specific examples have been used to illustrate the principle and implementation of the present invention. The above description of the embodiments is only for the purpose of helping to understand the method and core idea of ​​the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made to the present invention without departing from the principle of the present invention, and these improvements and modifications also fall within the protection scope of the claims of the present invention.

Claims

1. A polar 3,4-isoprene gum with self-healing function, characterized in that, It has the structure shown in general formula (Ⅰ): In equation (Ⅰ), E represents O or S; R represents a substituent on the benzene ring, which can be hydrogen, C1-C20 alkyl, C6-C20 aryl, C1-C20 halogen-containing alkyl, or halogen substituent; m represents the number of substituents R, which is an integer selected from 1 to 5. When m≥2, R can be the same or different. The x, y ratio can take any value within the range of 0.1 to 1000; The number-average molecular weight of the polar 3,4-isoprene gum is 1×10⁻⁶. 4 ~250×10 4 The value of n is 30 to 10000.

2. The polar 3,4-isoprene gum with self-healing function according to claim 1, characterized in that, The content of 3,4-structural units in the polar 3,4-isoprene gum is not less than 85%; the insertion rate of polar α-olefin structural units in the structure can be arbitrarily adjusted between 0.1% and 90%.

3. A method for preparing a polar 3,4-isoprene gum with self-healing function as described in claim 1 or 2, characterized in that, Includes the following steps: a) Under the protection of inert gases nitrogen or argon, the amidine-based rare earth catalyst is dispersed in an organic solvent to obtain a rare earth catalyst solution. The amidine-based rare earth catalyst consists of three parts: A, B, and C. composition: Wherein, A is a rare earth complex, which is the complex shown in formula (II): In formula (II), R1 is a substituent of the amidine carbon, which is a C1-C20 aryl, a C1-C20 halogenated aryl, a C1-C20 alkyl, or a C1-C20 halogenated alkyl. R2 and R3 are substituents on the nitrogen atom, and each is independently a C1-C20 aryl, a C1-C20 halogenated aryl, a C1-C20 alkyl, or a C1-C20 halogenated alkyl. The rare earth metal Ln is selected from Sc, Y, La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb or Lu; R4 and R5 are each independently C1-C10 alkyl, C1-C10 silyl, C1-C10 silamido, C1-C10 alkylamido, or C3-C10 allyl. L represents tetrahydrofuran, diethyl ether, ethylene glycol dimethyl ether, or toluene; m represents 0, 1, or 2. B is an organoboron reagent; C is an alkylaluminum, aluminumoxane, or diisobutylaluminum hydride; b) Using isoprene and polar α-olefin as monomer raw materials, the rare earth catalyst solution obtained in step a) is used to catalyze the polymerization reaction. After a certain polymerization time, the polymerization reaction is terminated, the product is precipitated and dried to obtain polar 3,4-isoprene gum. The structural formula of polar α-olefin monomers is shown in general formula (Ⅲ): In the formula, E represents O or S; R represents a substituent on the benzene ring, which can be hydrogen, C1-C20 alkyl, C6-C20 aryl, C1-C20 alkyl containing halogen, or a halogen substituent; m represents the number of substituents R, which is an integer selected from 1 to 5. When m≥2, R can be the same or different.

4. The method for preparing polar 3,4-isoprene gum with self-healing function according to claim 3, characterized in that, The polar α-olefin monomer is selected from one of the AW structures:

5. The method for preparing polar 3,4-isoprene gum with self-healing function according to claim 3, characterized in that, In the amidoyl rare earth catalyst, B is selected from [Ph3C][B(C6F5)4], [PhNMe2H][BPh4], [NEt3H][BPh4], [PhNMe2H][B(C6F5)4], or B(C6F5)3.

6. The method for preparing polar 3,4-isoprene gum with self-healing function according to claim 5, characterized in that, R1 is phenyl, p-methylphenyl, p-ethylphenyl, p-isopropylphenyl, p-tert-butylphenyl, benzyl, m-methylphenyl, m-ethylphenyl, m-isopropylphenyl, mestrimethylphenyl, 2,6-dimethylphenyl, 2,6-diethylphenyl, mestriethylphenyl or 2,6-diisopropylphenyl; R2 and R3 are each independently phenyl, p-methylphenyl, p-ethylphenyl, p-isopropylphenyl, p-tert-butylphenyl, benzyl, m-methylphenyl, m-ethylphenyl, m-isopropylphenyl, mesitylene, mesitylene, mesitylene, mesitylene, mesitylene, 2,6-dimethylphenyl, 2,6-diethylphenyl, 2,6-diisopropylphenyl, 2,6-diethyl-4-methylphenyl, 2,6-diethyl-4-tert-butylphenyl, 2,6-diisopropyl-4-methylphenyl, 2,6-ditert-butyl-4-methylphenyl, 2,6-diphenylphenyl, 2,6-ditrifluoromethylphenyl, 2-fluorophenyl, 3-trifluoromethylphenyl, p-trifluoromethylphenyl, or p-fluorophenyl. R4 and R5 are each independently CH3, CH2SiMe3, CH(SiMe3)2, N(SiMe3)2, NH(SiMe3) or 1,3-C3H5; B is either [Ph3C][B(C6F5)4] or [PhNMe2H][B(C6F5)4]; C is one or more of trimethylaluminum, triethylaluminum, tri-n-propylaluminum, tri-n-butylaluminum, triisopropylaluminum, triisobutylaluminum, tripentylaluminum, trihexylaluminum, tricyclohexylaluminum, trioctylaluminum, methylaluminoxane, ethylaluminoxane, n-propylaluminoxane, and n-butylaluminoxane.

7. The method for preparing polar 3,4-isoprene gum with self-healing function according to claim 3, characterized in that, The organic solvent is selected from one or a mixture of several of saturated alkanes, aromatics, halogenated aromatics, and cycloalkanes.

8. The method for preparing polar 3,4-isoprene gum with self-healing function according to claim 7, characterized in that, The organic solvent is selected from one or a mixture of several of toluene, xylene, benzene, n-hexane, n-heptane, cyclohexane, chlorobenzene, dichlorobenzene, and trichlorobenzene.

9. The method for preparing polar 3,4-isoprene gum with self-healing function according to claim 5, characterized in that, The molar ratio of the polar α-olefin monomer to the rare earth complex having the structure of formula (II) is (50-10000):1; the molar ratio of the isoprene monomer to the rare earth complex having the structure of formula (II) is (50-10000):1; the molar ratio of the organoboron salt to the rare earth complex having the structure of formula (II) is (0.5-2.0):1; and the molar ratio of the alkylaluminum compound to the rare earth complex having the structure of formula (II) is (0.5-3000):

1.

10. The method for preparing polar 3,4-isoprene gum with self-healing function according to claim 3, characterized in that, The polymerization reaction is carried out at a temperature of -60 to 80°C for 0.5 to 48 hours.

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