CN113912795A

CN113912795A - Polyisomonoolefin copolymer, preparation method thereof, initiator and application

Info

Publication number: CN113912795A
Application number: CN202111536847.8A
Authority: CN
Inventors: 伍一波; 刘若凡; 金玉顺
Original assignee: Beijing Institute of Petrochemical Technology
Current assignee: Beijing Institute of Petrochemical Technology
Priority date: 2021-09-30
Filing date: 2021-12-16
Publication date: 2022-01-11
Anticipated expiration: 2041-12-16
Also published as: CN113912795B; CN116425930A; CN116478350A

Abstract

The invention belongs to the field of high molecular compounds and preparation thereof, and particularly relates to a polyisomonoolefin copolymer, a preparation method thereof, an initiator and application thereof. The copolymer is prepared by copolymerizing a first monomer selected from the group consisting of isomonoolefins and a second monomer comprising an unsubstituted or substituted vinyl aromatic hydrocarbon under an initiator system. The copolymer is used as an asphalt modifier, a medical material, a 5G optical fiber protective layer or an elastomer in hot melt adhesive.

Description

Polyisomonoolefin copolymer, preparation method thereof, initiator and application

Technical Field

The invention belongs to the field of high molecular compounds and preparation thereof, and particularly relates to a polyisomonoolefin copolymer, a preparation method thereof, an initiator and application thereof.

Background

Polystyrene-isobutylene-styrene is a triblock copolymer prepared by active carbon cationic polymerization of isobutylene as a main monomer and styrene as a second monomer, polystyrene as a hard segment and polyisobutylene as a soft segment are subjected to covalent bonding and microphase separation, and a polystyrene phase is physically crosslinked in a polyisobutylene phase to form a thermoplastic elastomer. SIBS can be obtained by varying the styrene/isobutylene ratio and molecular mass during the polymerization process to obtain different mechanical properties, with lower styrene ratios providing similar mechanical properties to rubber, and higher ratios providing similar mechanical properties to toughened plastics.

Patent document CN1982350A reports that a diblock copolymer is obtained by cationic polymerization using water as an initiator and lewis acid as a co-initiator, and then adding an isoolefin or a styrenic second monomer containing an additive. And adding a first monomer containing an additive, and carrying out third-stage polymerization to obtain a triblock copolymer, wherein the molecular weight of the SIBS polymer prepared by the method is low, and an active center is unstable and easy to transfer, so that side reactions are easy to occur and difficult to control. In addition, the processes reported in other documents have the problems of wide molecular weight distribution of the obtained product, too high molecular weight and difficult processing and the like. For example, patent document CN1283681C reports a method for preparing isobutylene block copolymer by sequential initiation, but this preparation method requires addition of new lewis acid during the second-stage monomer copolymerization, and the synthesis process is complicated.

Disclosure of Invention

To ameliorate the above problems, the present invention provides a copolymer prepared by copolymerizing a first monomer selected from isomonoolefins and a second monomer comprising an unsubstituted or substituted vinyl aromatic hydrocarbon under an initiator system.

According to an embodiment of the invention, the copolymer is a thermoplastic copolymer (thermoplastic elastomer) or a thermosetting copolymer (thermosetting elastomer).

According to an embodiment of the invention, the copolymer has a soft block of a polyisomonoolefin.

According to an embodiment of the invention, the first monomer is selected from isobutylene.

According to an embodiment of the invention, in the second monomer, the substituent of the substituted vinyl aromatic hydrocarbon is located on the aromatic hydrocarbon ring and may be selected from one or more of the following groups: halogen, unsubstituted or halogenated C_1-10An alkyl group.

According to an embodiment of the invention, the aromatic hydrocarbon is selected from C_6-20Aromatic hydrocarbons, preferably benzene.

According to an embodiment of the present invention, the second monomer may comprise a monomer selected from styrene or a styrene derivative. Preferably, the styrene derivative is selected from substituted styrenes. Wherein a substituent of styrene is substituted on the phenyl or vinyl group and is selected from one or more of the following groups: halogen, C_1-10Alkyl or halo C_1-10An alkyl group.

Preferably, the second monomer is selected from one, two or more of the following compounds: styrene; by one or more C_1-10Alkyl-substituted styrenes such as alpha-methylstyrene, p-methylstyrene, m-methylstyrene, p-ethylstyrene, p-tert-butylstyrene; styrene substituted with one or more halogens, such as p-chlorostyrene, p-bromostyrene; by one or more monohaloalkyl or polyhaloC_1-10Alkyl-substituted styrenes such as p-chloromethylstyrene, p-bromomethylstyrene; phenyl and C_4-8Cycloalkenyl-fused styrenes, such as 4-vinylbenzocyclobutene (4-VBCB).

According to a preferred embodiment of the invention, the second monomer comprises a monomer a selected from one, two or more of the following compounds: styrene; by one or more C_1-10Alkyl-substituted styrenes such as alpha-methylstyrene, p-methylstyrene, m-methylstyrene, p-ethylstyrene, p-tert-butylstyrene; styrene substituted with one or more halogens, such as p-chlorostyrene, p-bromostyrene; by one or more monohaloalkyl or polyhaloC_1-10Alkyl-substituted styrenes such as p-chloromethylstyrene, p-bromomethylstyrene;

and the number of the first and second groups,

optionally present or absent, monomers B selected from one, two or more of the following compounds: phenyl and C_4-8Cycloalkenyl-fused styrenes, such as 4-vinylbenzocyclobutene.

According to an embodiment of the present invention, the copolymer may be a thermoplastic elastomer.

According to an exemplary embodiment of the invention, the second monomer of the thermoplastic elastomer is selected from monomers a, which are selected from one, two or more of the following compounds: styrene; by one or more C_1-10Alkyl-substituted styrenes such as alpha-methylstyrene, p-methylstyrene, m-methylstyrene, p-ethylstyrene, p-tert-butylstyrene; styrene substituted with one or more halogens, such as p-chlorostyrene, p-bromostyrene; by one or more radicals selected from monohaloalkyl or polyhaloC_1-10And styrene substituted with a substituent of an alkyl group, such as p-chloromethylstyrene and p-bromomethylstyrene. Preferably, the monomer a is selected from styrene.

According to an embodiment of the present invention, the thermoplastic elastomer copolymer comprises a linear polystyrene-isobutylene-styrene (SIBS) triblock copolymer, a three-armed radial polystyrene-isobutylene-styrene (SIBS) triblock copolymer;

preferably, the linear polystyrene-isobutylene-styrene (SIBS) triblock copolymer has a structure as shown in formula (i) and the three-armed radial polystyrene-isobutylene-styrene (SIBS) triblock copolymer has a structure as shown in formula (ii).

Wherein each x is the same or different and is independently selected from a number of 40 to 7000, preferably from 80 to 5000, for example 80, 100, 200, 300, 400, 500, 600, 700, 800, 900, 1000, 2000, 3000, 4000 or 5000;

each y is the same or different and is independently selected from a number of 20 to 3000, preferably 50 to 2000, for example 50, 100, 200, 300, 400, 500, 600, 700, 800, 900, 1000 or 2000.

According to an embodiment of the present invention, the copolymer may be a thermosetting elastomer.

According to a preferred embodiment of the invention, the second monomer of the thermosetting elastomer comprises a monomer a selected from one, two or more of the following compounds: styrene; by one or more C_1-10Alkyl-substituted styrenes such as alpha-methylstyrene, p-methylstyrene, m-methylstyrene, p-ethylstyrene, p-tert-butylstyrene; styrene substituted with one or more halogens, such as p-chlorostyrene, p-bromostyrene; by one or more monohaloalkyl or polyhaloC_1-10Alkyl-substituted styrenes such as p-chloromethylstyrene, p-bromomethylstyrene;

and the number of the first and second groups,

monomer B selected from one, two or more of the following compounds: phenyl and C_4-8Cycloalkenyl-fused styrenes, such as 4-vinylbenzocyclobutene.

According to an exemplary aspect of the present invention, the second monomer of the thermosetting elastomer includes styrene and 4-vinylbenzocyclobutene.

According to an embodiment of the present invention, the molar ratio of the monomer A to the monomer B in the second monomer is (80-100): 0-20), preferably (90-100): 0-10, and preferably the content of the monomer B is not 0. For example, the molar ratio of monomer A to monomer B is 95: 5.

According to an embodiment of the present invention, the thermosetting elastomeric copolymer comprises a linear poly (styrene-co-block-4-vinylbenzocyclobutene) -polyisobutylene-poly (styrene-co-block-4-vinylbenzocyclobutene) triblock copolymer (xSIBS), a three-arm star-shaped poly (styrene-co-block-4-vinylbenzocyclobutene) -polyisobutylene-poly (styrene-co-block-4-vinylbenzocyclobutene) triblock copolymer (xSIBS).

Preferably, the linear poly (styrene-co-block-4-vinylbenzocyclobutene) -polyisobutylene-poly (styrene-co-block-4-vinylbenzocyclobutene) triblock copolymer (xSIBS) has a structure as shown in formula (iii), and the three-arm star-shaped poly (styrene-co-block-4-vinylbenzocyclobutene) -polyisobutylene-poly (styrene-co-block-4-vinylbenzocyclobutene) triblock copolymer (xSIBS) has a structure as shown in formula (iv):

wherein each x is the same or different and is independently selected from a number of 40 to 7000, preferably 80 to 5000, for example 80, 100, 200, 300, 400, 500, 600, 700, 800, 900, 1000, 2000, 3000, 4000 or 5000;

Each m is identical or different and is independently selected from a number from 0 to 10, preferably from 0 to 1, for example 0.01, 0.02, 0.03, 0.04, 0.05, 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9 or 1.

According to an embodiment of the present invention, the Mn of the copolymer may be 4.0 × 10³To 5.0X 10⁵For example 2.0X 10⁴To 2.0X 10⁵。

According to an embodiment of the invention, the copolymer may have a molecular weight distribution coefficient Mw/Mn of 1.10 to 2.50, such as 1.10 to 2.00, for example 1.15 to 1.40, preferably 1.17 to 1.36.

According to an embodiment of the invention, the second monomer is present in the copolymer in an amount selected from 5wt% to 50wt%, for example, in an amount selected from 5wt%, 6wt%, 7wt%, 8wt%, 9wt%, 10wt%, 11wt%, 12wt%, 13wt%, 14wt%, 15wt%, 16wt%, 17wt%, 18wt%, 19wt%, 20wt%, 21wt%, 22wt%, 23wt%, 24wt%, 25wt%, 26wt%, 27wt%, 28wt%, 29wt%, 30wt%, 31wt%, 32wt%, 33wt%, 34wt%, 35wt%, 36wt%, 37wt%, 38wt%, 39wt%, 40wt%, 41wt%, 42wt%, 43wt%, 44wt%, 45wt%, 46wt%, 47wt%, 48wt%, 49wt% or 50wt%

According to an embodiment of the present invention, the total content of the second monomer in the copolymer is 20wt% to 50wt% when monomer a is present and monomer B is absent.

According to an embodiment of the present invention, when monomer A, B is present together, the second monomer content is 5wt% to 50wt% in the copolymer.

According to an embodiment of the present invention, in the copolymer, the molecular weight of the first monomer segment may be 0.2 to 40 ten thousand, for example, 0.2 ten thousand, 0.5 ten thousand, 1.0 ten thousand, 5.0 ten thousand, 10.0 ten thousand, 15.0 ten thousand, 20.0 ten thousand, 25.0 ten thousand, 30.0 ten thousand, 35.0 ten thousand, or 40.0 ten thousand; the molecular weight of the second monomer segment may be in the range of 0.2 to 30 million, for example 0.2, 0.5, 1.0, 5.0, 10.0, 15.0, 20.0, 25.0 or 30.0 million.

According to a preferred embodiment of the invention, the mass percentage of gel in the copolymer is below 5wt%, preferably below 5wt%, for example below 3wt%, below 2wt%, below 1wt%, below 0.5wt%, below 0.4wt%, below 0.3wt%, below 0.2 wt% or below 0.1 wt%.

According to the embodiment of the invention, the thermoplastic elastomer copolymer has the elongation at break of 200-1100% and the ultimate tensile strength of 4-30 MPa.

According to an embodiment of the present invention, the thermosetting elastomer copolymer has an elongation at break of 200% to 1100% and an ultimate tensile strength of 4.5MPa to 50 MPa.

The present invention also provides a process for the preparation of a copolymer, preferably as described above, for example for the preparation of the thermoplastic elastomer or thermoset elastomer, which comprises preparing the copolymer, for example the thermoplastic elastomer or thermoset elastomer, by copolymerization of a first monomer and a second monomer, wherein the first monomer and the second monomer have the definitions as described above, under an initiator system.

Preferably, the first monomer is added in portions to the initiator system.

According to an embodiment of the invention, the initiator system comprises at least one initiator, for example selected from a primary initiator or a combination of a primary initiator and a co-initiator.

According to an embodiment of the present invention, the primary initiator is selected from at least one of a bifunctional initiator, a multifunctional initiator. Illustratively, the difunctional initiators are used to prepare linear polymers. Illustratively, the multifunctional initiator is used to prepare a three-arm star polymer.

According to an embodiment of the invention, the bifunctional initiator presents two functional groups, identical or different from each other.

Preferably, the difunctional initiator includes, but is not limited to, at least one selected from the group consisting of: p-cumyl alcohol, p-cumyl chloride, 1, 3-bis (2-chloroisopropyl) benzene, 5-tert-butyl-1, 3-bis (2-chloroisopropyl) benzene, 1, 3-bis (2-methoxyisopropyl) benzene or 5-tert-butyl-1, 3-bis (2-methoxyisopropyl) benzene.

According to an embodiment of the present invention, the multifunctional initiator has three or more functional groups identical to each other or three or more functional groups, at least one of which is different from the other functional groups.

Preferably, the multifunctional initiator includes, but is not limited to, at least one selected from the group consisting of: 1,3, 5-tri-cumyl alcohol, 1,3, 5-tris (2-chloroisopropyl) benzene or 1,3, 5-tris (2-methoxyisopropyl) benzene.

According to an embodiment of the present invention, the primary initiator is at least one selected from the group consisting of compounds represented by the following formula (a):

（A）

wherein X is selected from tBu (tert-butyl), iPr (isopropyl), OMe (methoxy), 2-methoxyisopropyl, 2-chloroisopropyl, NO₂Cl, Br, I or H;

each Y is the same or different and is independently selected from H, NO₂Isopropyl or tert-butyl;

z is selected from H, NO₂Or a tert-butyl group;

r is selected from Cl, methyl (-Me) or methoxy (-OMe).

According to an embodiment of the present invention, the compound represented by formula (a) may be selected from compounds 1 to 22 having the following groups X, Y, Z and R:

compound (I)

1

2

3

4

5

6

7

8

9

10

11

12

X

tBu

iPr

OMe

Y

H

NO₂

H

NO₂

H

NO₂

iPr

Z

H

NO₂

H

NO₂

H

NO₂

H

NO₂

H

NO₂

R

Cl

Compound (I)

13

14

15

16

17

18

19

20

21

22

X

NO₂

Cl

Br

I

H

2-chloro-isopropyl

2-methoxy isopropyl group

Y

H

iPr

tBu

iPr

NO₂

H

Z

H

NO₂

tBu

NO₂

H

R

Cl

OMe

According to an embodiment of the invention, when X is tBu and Y is H, Z is H, R is Me, the compound of formula (a) is compound 1, i.e. 5-tert-butyl-1, 3-bis (2-chloroisopropyl) benzene.

According to an embodiment of the invention, when X is ClC (CH)₃)₂When Y is H, Z is H, R is Cl, the compound represented by the formula (A) is a compound 21, i.e., 1,3, 5-tris (2-chloroisopropyl) benzene.

According to an embodiment of the invention, when X is CH₃OC(CH₃)₂When Y is H, Z and OMe is H, R, the compound represented by formula (A) is compound 22, i.e., 1,3, 5-tris (2-methoxyisopropyl) benzene.

According to an embodiment of the invention, the method of preparing the copolymer comprises cationic polymerization. For example, the copolymer can be prepared by adding a first monomer to the initiator system in portions to initiate polymerization, followed by addition of a second monomer to copolymerize.

According to an embodiment of the invention, the copolymer is prepared by first adding a first portion of the first monomer to the initiator system, followed by the addition of a second portion of the first monomer, followed by the addition of the second monomer.

According to embodiments of the present invention, an exemplary method of batch addition of a first monomer may comprise: firstly, initiating polymerization by adding a first part of first monomers and the initiator system to form a stable primary active center; and then adding a second part of the first monomer to prepare the polyisomonoolefin containing the multi-active chain end. The inventors have found that this way of adding the first monomer in batches is effective in avoiding severe chain transfer and chain termination reactions due to excessive concentrations of exotherm.

Preferably, the first portion of the first monomer is added in an amount less than the second portion of the first monomer. Further preferably, the first portion of the first monomer comprises less than 40wt%, such as 3wt% to 40wt%, preferably 10wt% to 30wt%, of the total mass of the first monomer; the second part of the first monomer is the rest of the first monomer except the first part of the first monomer.

According to an embodiment of the invention, the conversion of the second monomer reaches 50wt% to 100 wt%.

According to an embodiment of the invention, the preparation process is carried out in the presence of a solvent. The solvent is selected from at least one of chloroalkane, methylcyclohexane or cyclohexane.

Preferably, the chlorinated alkane is selected from monochloro or polychlorinated methanes.

Further, the methyl chloride is selected from at least one of methyl chloride, dichloromethane or trichloromethane.

Further preferably, the solvent system is selected from mixed solvents. Illustratively, the mixed solvent is selected from cyclohexane and methyl chloride, and hexane and methyl chloride.

According to an embodiment of the present invention, preferably, in order to enhance participation of the second monomer styrene and its derivatives in the block polymerization, the second monomer is provided in the form of a second monomer solution.

Preferably, the flow rate of the second monomer solution is 0.1-10 mL/s, for example, the flow rate is controlled by a metering pump or a separating funnel, so that the heat release amount per unit time is reduced, the uniform heat release of the reaction is ensured, and the occurrence of side reactions is avoided.

According to an embodiment of the invention, the initiator system further comprises a third component.

According to a preferred embodiment of the invention, the initiator system further comprises a proton scavenger.

Preferably, the third component is selected from aromatic compounds having a P-pi conjugation.

Preferably, the aromatic compound is selected from at least one of aromatic ester, aromatic ether or aromatic ketone.

Further preferably, the aromatic ketone is selected from at least one of benzophenone, acetophenone, 2, 4-dimethylacetophenone, phenyl acetone and the like.

Further preferably, the aromatic ether is at least one selected from anisole, phenetole, diphenyl ether, p-ethylphenyl ether, n-butylphenyl ether, p-tert-butylphenyl ether and the like.

More preferably, the aromatic ester is at least one selected from the group consisting of methyl benzoate, ethyl phenylacetate, dimethyl terephthalate, diethyl terephthalte acetate, diethyl isophthalate, diethyl phthalate, dibutyl terephthalate, diethyl 2, 6-dimethyl terephthalate, dimethyl phthalate, diethyl phthalate, diisooctyl phthalate, and the like.

Preferably, the proton scavenger is selected from tertiary amine compounds, such as substituted or unsubstituted aromatic tertiary amine compounds, examples of which may be selected from at least one of 2, 6-di-tert-butylpyridine, 2, 6-di-tert-butyl-4-methylpyridine, or 2,4, 6-tri-tert-butylpyridine.

According to an embodiment of the invention, the initiator system further comprises a co-initiator.

Preferably, the coinitiator is selected from at least one of titanium tetrachloride, ferric chloride, boron trifluoride, boron trichloride, gallium trichloride, aluminum chloride, alkyl aluminum chloride (such as monoethylaluminum dichloride or triethylaluminum trichloride).

According to an embodiment of the present invention, the co-initiator may be added to the initiator system after the first portion of the first monomer is added to initiate polymerization of the first portion of isobutylene.

Further, the mass fraction of the sum of the first monomer and the second monomer in the total reaction system is 5wt% -45 wt%.

Further, in the preparation of the thermosetting elastomer, the molar ratio of the monomer A (such as styrene) to the monomer B (such as 4-vinylbenzocyclobutene) in the second monomer is (80-100): 0-20, preferably (90-100): 0-10, for example (90-100): 1-10); wherein in the molar ratio of the monomer A to the monomer B, when the proportion value of the monomer A is 90-100, the proportion value can be selected from 90, 91, 92, 93, 94, 95, 96, 97, 98, 99 or 100; when the ratio of the monomer B is 0 to 10, it may be selected from 0, 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1.0, 1.5, 2.0, 2.5, 3.0, 3.5, 4.0, 4.5, 5.0, 5.5, 6.0, 6.5, 7.0, 7.5, 8.0, 8.5, 9.0, 9.5 or 10.0. By way of example, the molar ratio of monomer a to monomer B may be 95: 5.

According to an embodiment of the invention, the molar ratio of the third component to the main initiator in the initiator system, when present, is (0 to 10: 1, e.g. 0:1, 0.1:1, 0.2:1, 0.3:1, 0.4:1, 0.5:1, 0.6:1, 0.7:1, 0.8:1, 0.9:1, 1.0:1, 1.5:1, 2.0:1, 2.5:1, 3.0:1, 3.5:1, 4.0:1, 4.5:1, 5.0:1, 5.5:1, 6.0:1, 6.5:1, 7.0:1, 7.5:1, 8.0:1, 8.5:1, 9.0:1, 9.5:1 or 10.0: 1.

According to an embodiment of the invention, the molar ratio of the main initiator and the co-initiator in the initiator system, when present, is 1 (2 to 50), such as 1:2, 1:3, 1:4, 1:5, 1:6, 1:7, 1:8, 1:9, 1:10, 1:15, 1:20, 1:25, 1:30, 1:35, 1:40, 1:45, 1: 50.

According to an embodiment of the invention, the molar ratio of the primary initiator and the first monomer is 1 (40 to 7000), such as 1:50, 1:100, 1:200, 1:500, 1:1000, 1:1500, 1:2000, 1:2500, 1:3000, 1:3500, 1:4000, 1:4500, 1:5000, 1:5500, 1:6000, 1:6500 or 1: 7000.

According to an exemplary embodiment of the invention, when a proton scavenger is present, the molar ratio of the proton scavenger to the primary initiator in the initiator system is (0-5: 1), e.g., 0.1:1, 0.2:1, 0.3:1, 0.4:1, 0.5:1, 0.6:1, 0.7:1, 0.8:1, 0.9:1, 1.0:1, 1.5:1, 2.0:1, 2.5:1, 3.0:1, 3.5:1, 4.0:1, 4.5:1, or 5.0: 1.

According to an embodiment of the present invention, the temperature range of the copolymerization reaction in the preparation process is-100 ℃ to-50 ℃, preferably-90 ℃ to-50 ℃, such as-90 ℃, 80 ℃, 70 ℃, 60 ℃ or-50 ℃.

According to an embodiment of the invention, the mass percentage of gel in the copolymer obtained by the preparation method is below 5wt%, preferably below 5wt%, for example below 3wt%, below 2wt%, below 1wt%, below 0.5wt%, below 0.4wt%, below 0.3wt%, below 0.2 wt% or below 0.1 wt%.

According to an embodiment of the present invention, the preparation process forms stable linear and/or star polymer structures.

The inventors have surprisingly found that styrene and its derivatives are electron-rich structures and are susceptible to nucleophilic attack by carbenium ions to generate alkylation reaction (the reaction process shown in the following reaction formula v), which results in severe cross-linking between macromolecular chains, thereby forming insoluble gel in the system. For example, CN201710177847.0 discloses that the styrene content in the block copolymer is not over 20wt%, because in the process of this document, if the styrene content in the block copolymer is further increased, intermolecular crosslinking is liable to occur at the end of the polymerization to form a high content gel, and the reaction mechanism is shown in the following reaction formula v.

The invention discovers that at least one of aromatic ester, aromatic ether or aromatic ketone is used as a third component, or the third component is matched with a proton trapping agent, so that the gel content generated in copolymerization can be effectively reduced, the conversion rate of the second monomer styrene and derivatives thereof participating in reaction can be effectively improved, the charge of a carbocation active center can be reduced, and the active center of carbocation can be stabilized.

According to an embodiment of the present invention, a thermosetting elastomer is obtained by mixing and adding 4-vinylbenzocyclobutene while adding the second monomer styrene, thereby copolymerizing 4-vinylbenzocyclobutene copolymerized units to the polystyrene-based hard segment of the SIBS. At least one selected from aromatic ester, aromatic ether or aromatic ketone is added as a third component, or a proton scavenger is added to effectively solve the problem that 4-VBCB is difficult to participate in copolymerization reaction and difficult to copolymerize with a first monomer during block polymerization, and then the mechanical property of the material is greatly improved through thermal crosslinking (a reaction process shown in the following reaction formula vi).

The present invention also provides an initiator having a structure represented by formula (a) as described above, for example, compounds 1 to 22 as described above.

The invention also provides a preparation method of the initiator, which specifically comprises the following steps:

(1) carrying out esterification reaction on the compound B and methanol in concentrated sulfuric acid to generate an intermediate product B-1;

(2) carrying out a Grignard reaction on the intermediate product B-1 and a Grignard reagent in an organic solvent to generate an intermediate product B-2;

(3) the intermediate product B-2 and methanol are subjected to acidification reaction to obtain a compound A, or

(4) And (3) introducing dry hydrogen chloride gas into the solution of the intermediate product B-2 in dichloromethane to obtain the compound A.

Wherein in the compound B, X' is selected from tBu, iPr, OMe, -COOH and NO₂Cl, Br, I or H;

in the intermediate B-1, X '' is selected from tBu, iPr, OMe, -COOMe, NO₂Cl, Br, I or H;

in intermediate B-2, X ' ' ' is selected from tBu, iPr, OMe, -C (CH)₃）₂OH、NO₂Cl, Br, I or H;

x, Y, Z, R have the meaning as described above.

According to an embodiment of the invention, the preparation process is preferably carried out under an atmosphere inert to the reaction, for example under a nitrogen atmosphere.

According to an embodiment of the invention, in step (2), the grignard reagent is selected from CH₃MgBr and/or CH₃MgI。

According to an embodiment of the present invention, in the step (2), the organic solvent comprises at least one selected from the group consisting of tetrahydrofuran, 2-methyltetrahydrofuran, and cyclopentyl methyl ether.

Preferably, the organic solvent also comprises an optionally present aromatic hydrocarbon solvent, such as benzene or toluene. For example, the aromatic hydrocarbon solvent accounts for 0 to 50 percent of the volume of the organic solvent. When present, the aromatic hydrocarbon solvent comprises from 1% to 50% by volume of the organic solvent, for example 1%, 2%, 3%, 4%, 5%, 10%, 15%, 20%, 25%, 30%, 35%, 40%, 45% or 50%.

According to an embodiment of the present invention, in the step (2), the reaction temperature is 0 ℃ to 40 ℃.

According to an embodiment of the present invention, in the step (3), the acidification reaction is performed in the presence of an acidification catalyst. Preferably, the acidification catalyst is selected from sulfuric acid.

According to the embodiment of the invention, in the preparation method, the intermediate products B-1 and B-2 in the reaction process are subjected to extraction, washing, recrystallization and drying processes, so that the problem of difficult preparation and post-treatment processes is solved, and the product purity is at least 95%.

According to an embodiment of the present invention, in the production method, the steps (2), (3) preferably include a quenching step. The quenching step can be carried out in a mode of slowly dripping firstly and then pouring a terminator, so that the phenomenon that the exothermic reaction is violent and the quality of a product is influenced is avoided. Preferably, the terminating agent is selected from aqueous sodium sulfite solution and/or aqueous ammonium chloride solution, preferably saturated aqueous sodium sulfite solution and/or saturated aqueous ammonium chloride solution.

According to the embodiment of the invention, in the preparation method, in the step (4), the dry hydrogen chloride gas is continuously introduced for 12-48 hours. Preferably, in step (4), the off-gas is slowly absorbed with an alkaline aqueous solution, such as an aqueous sodium hydroxide solution, to prevent environmental pollution.

According to an embodiment of the invention, in the preparation process, when X' in B is selected from tBu, iPr, OMe, NO₂Cl, Br, I or H, B can be obtained by oxidizing B' with potassium permanganate.

According to an exemplary embodiment of the present invention, the method for preparing compounds 1-20 specifically comprises the steps of:

(1) adding acid potassium permanganate into SM-0 to oxidize to generate a product SM-01;

(2) carrying out esterification reaction on SM-01 and methanol in concentrated sulfuric acid to generate a product SM-02;

(3) carrying out a Grignard reaction on SM-02 and a Grignard reagent to generate a product SM-03;

(4) introducing dry hydrogen chloride gas into the SM-03 in a dichloromethane solution to obtain a product SM-04; wherein SM-04 is selected from any one of compounds 1-20;

；

wherein X, Y, Z has the meaning as described above;

IPA for isopropanol, THF for tetrahydrofuran, and DCM for dichloromethane.

According to an exemplary embodiment of the present invention, the method of preparing compounds 21-22 may comprise the steps of:

(1) reacting the I with methanol in concentrated sulfuric acid to generate a product II;

(2) II, performing a Grignard reaction with a Grignard reagent in a solvent to generate a product III;

(3) III reacts with concentrated sulfuric acid in methanol to generate a product IV, namely a compound 22; or III, introducing dry hydrogen chloride gas into a dichloromethane solution to obtain a product V, namely a compound 21;

；

the invention also provides a preparation method of the compound B-2, which comprises the step of carrying out Grignard reaction on the compound B-1 and a Grignard reagent in an organic solvent to prepare the compound B-2. Wherein the organic solvent and the grignard reagent have the meanings as described above.

The invention also provides application of an organic solvent containing at least one of tetrahydrofuran, 2-methyltetrahydrofuran and cyclopentyl methyl ether in preparation of the compound B2.

Preferably, the organic solvent further comprises an aromatic hydrocarbon solvent, such as benzene or toluene. For example, the toluene is present in an amount of 0% to 50% by volume of the organic solvent.

The invention also provides the use of the copolymer (such as a thermoplastic elastomer or a thermosetting elastomer), for example, the copolymer can be used in the aspects of asphalt modifiers, medical fields such as medical materials, 5G optical fiber protective layers or hot melt adhesives, and the like, for example, as an elastomer in the aspects of asphalt modifiers, medical materials, 5G optical fiber protective layers or hot melt adhesives.

The medical material may be selected from materials such as glaucoma catheters (drainage tubes), intracorneal contact lenses, intraocular lenses, drug delivery vehicles, vascular grafts, tissue fillers.

Definition and description of terms

Unless otherwise indicated, the definitions of groups and terms described in the specification and claims of the present application, including definitions thereof as examples, exemplary definitions, preferred definitions, definitions described in tables, definitions of specific compounds in the examples, and the like, may be arbitrarily combined and coupled with each other. The definitions of the groups and the structures of the compounds in such combinations and after the combination are within the scope of the present specification.

Unless otherwise indicated, the numerical ranges set forth in the specification and claims are equivalent to at least each and every specific integer numerical value set forth therein. For example, a numerical range of "1 to 10" is equivalent to reciting each integer value in the numerical range of "1 to 10," i.e., 1,2, 3, 4, 5, 6, 7, 8, 9, 10. Further, when certain numerical ranges are defined as "numbers," it should be understood that the two endpoints of the range, each integer within the range, and each decimal within the range are recited. For example, "a number of 1 to 10" is to be understood as describing not only each integer of 1,2, 3, 4, 5, 6, 7, 8, 9 and 10 but also at least the sum of each integer and 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, respectively.

It is to be understood that when one or more is described herein, "a plurality" shall mean more than two, for example, an integer of 2 or more, such as 3, 4, 5, 6, 7, 8, 9, or 10.

The term "halogen" denotes fluorine, chlorine, bromine and iodine, preferably chlorine or bromine.

The term "C_1-10Alkyl is understood to mean a straight-chain or branched saturated monovalent hydrocarbon radical having from 1 to 10 carbon atoms. For example, "C_1-6Alkyl "denotes straight-chain and branched alkyl groups having 1,2, 3, 4, 5 or 6 carbon atoms. The alkyl group is, for example, a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, an isopropyl group, an isobutyl group, a sec-butyl group, a tert-butyl group, an isopentyl group, a 2-methylbutyl group, a 1-ethylpropyl group, a 1, 2-dimethylpropyl group, a neopentyl group, a 1, 1-dimethylpropyl group, a 4-methylpentyl group, a 3-methylpentyl group, a 2-ethylbutyl group, a 1-ethylbutyl group, a 3, 3-dimethylbutyl group, a 2, 2-dimethylbutyl group, a 1, 1-dimethylbutyl group, a 2, 3-dimethylbutyl group, a 1, 3-dimethylbutyl group or a 1, 2-dimethylbutyl group, or the like, or isomers thereof.

The term "halo C_1-10Alkyl "means C substituted by one or more halogens_1-10An alkyl group. Unless otherwise stated, C_1-10Alkyl groups have the definitions described above.

The term "vinyl aromatic hydrocarbon" means an aromatic hydrocarbon substituted with a vinyl group.

The term "aromatic hydrocarbon" is understood to mean a monocyclic, bicyclic (e.g. fused, bridged, spiro) or tricyclic hydrocarbon ring with aromatic character, which may be a monoaromatic ring or a polyaromatic ring fused together, preferably "C_6-20Aromatic hydrocarbon "or" C_6-14Aromatic hydrocarbons ". For example, "C_6-14Arene "is understood as preferably meaning a mono-, bi-or tricyclic hydrocarbon ring having a monovalent or partial aromaticity of 6, 7, 8, 9, 10, 11, 12, 13 or 14 carbon atoms (" C_6-14Aromatic hydrocarbons "), in particular a ring having 6 carbon atoms (" C ")₆Aromatic hydrocarbons) such as benzene. When said C is_6-20When the arene is substituted, it may be mono-or poly-substituted. And, the substitution site thereof is not limited, and may be, for example, ortho-, para-or meta-substitution.

Advantageous effects

1. The inventor surprisingly finds that the gel content of the polyisomonoolefin copolymer (such as thermoplastic/thermosetting elastomer) is obviously reduced, the prepared copolymer has controllable structure, molecular weight and comonomer ratio, excellent mechanical property, narrower molecular weight distribution, excellent biocompatibility and wide application prospect, and can be used as a raw material for preparing controlled release drugs, external catheters, implanted stents and the like, for example, in the fields of ophthalmic implant materials, vascular stent coatings, glaucoma catheters, heart valves and the like.

2. The invention adds the third component into the initiator system of the polyisomonoolefin copolymer to form stable primary active center. And by controlling the feeding rate of the second monomer, the gel phenomenon in block polymerization is effectively inhibited, the conversion rate of the styrene and the derivatives thereof participating in the reaction is improved, and a stable linear and star structure is formed.

3. According to the invention, a 4-vinylbenzocyclobutene (4-VBCB) copolymerization unit is copolymerized to a polystyrene-based hard segment of the SIBS to obtain the poly (styrene-co-block-4-vinylbenzocyclobutene) -polyisobutylene-poly (styrene-co-block-4-vinylbenzocyclobutene) triblock thermosetting elastomer copolymer. The difficult problem that the 4-VBCB is low in activity and not easy to participate in copolymerization is solved, the ultimate tensile strength of the material can be greatly improved in a thermal crosslinking mode, and the hardness of the material and the strength after heating crosslinking can be controlled by regulating and controlling the using amount of the 4-VBCB.

4. The invention relates to a preparation method of copolymer elastomer taking polyisobutylene as soft segment, which is prepared by an active/controllable cationic polymerization system and an initiator system in a batch feeding mode. In the preparation method, the polymerization of the first part of the low-concentration isobutene is initiated to form a stable primary active center; followed by addition of a second portion of the isobutylene monomer to produce a polyisobutylene containing multiple living chain ends, followed by addition of a second monomer styrene and its derivatives to produce a linear or three-armed radial polystyrene-isobutylene-styrene triblock copolymer (SIBS), a linear or three-armed radial poly (styrene-co-block-4-vinylbenzocyclobutene) -polyisobutylene-poly (styrene-co-block-4-vinylbenzocyclobutene) triblock copolymer (xsibss). The invention effectively avoids serious chain transfer and chain termination reaction caused by excessive concentration of heat release by adding isobutene in batches, and the molecular weight distribution of the polymer is narrow, thereby obtaining the linear or three-arm star polymer with controllable molecular structure.

5. The invention also provides a new method for preparing the bifunctional and polyfunctional main initiator by improving the process conditions, solves the potential danger that the solvent is easy to explode when being contacted with air in the traditional Grignard reaction, and promotes the complete conversion of the product. In the preparation method of the main initiator, the invention improves the problem of difficult preparation and post-treatment processes, greatly improves the production efficiency, and successfully enlarges the preparation process of the main initiator to the scale meeting the industrial production level. By developing a series of novel initiator derivatives, the initiator for cationic polymerization with higher initiation efficiency and high purity is prepared, and the linear or three-arm star polymer with controllable molecular structure can be synthesized by using the initiator.

Drawings

FIG. 1 is a nuclear magnetic diagram of the bifunctional initiator (Compound 1) of preparation example 1.

Detailed Description

The technical solution of the present invention will be further described in detail with reference to specific embodiments. It is to be understood that the following examples are only illustrative and explanatory of the present invention and should not be construed as limiting the scope of the present invention. All the technologies realized based on the above-mentioned contents of the present invention are covered in the protection scope of the present invention.

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

Preparation example

Preparation example 1 preparation of bifunctional initiator (Compound 1)

SM-0, SM-1, SM-2, SM-3, hereinafter of this example, have the chemical structures described above, where when present, X is tBu, Y is H, Z is H, and R is Cl.

(1) Firstly, sequentially adding IPA (isopropyl alcohol), water and SM-0 into a reaction kettle; subsequently, the temperature was increased and 3.0kg of KMnO was added in portions₄And then the reaction was carried out under reflux with stirring. And (3) cooling the reaction system to room temperature, dropwise adding saturated sodium sulfite to terminate the reaction, collecting the centrifugate, collecting the solid, airing, and drying to obtain the product SM-01.

(2) And sequentially adding methanol and SM-01 into the reaction kettle, heating to reflux, then dropwise adding concentrated sulfuric acid, and reacting after dropwise adding. And then cooling the system to room temperature, centrifuging to obtain a white solid, and drying to obtain a white solid product SM-02.

(3) Adding SM-02, 2-methyltetrahydrofuran and toluene solvent (v: v =60: 40) into the reaction kettle in sequence, and slowly dropwise adding CH₃MgBr, introducing nitrogen to protect the whole system, stirring at room temperature for reaction, and dropwise adding saturated ammonium chloride for quenching reaction after the raw materials are completely converted. The aqueous phase was extracted once with ethyl acetate, the organic phases were then combined, washed again, dried and concentrated to give a crude white solid, which was recrystallized to give SM-03 in 95% yield.

(4) Adding SM-03 and dichloromethane into the reaction kettle in sequence, continuously introducing dry hydrogen chloride gas into the reaction system, and slowly absorbing tail gas by using a sodium hydroxide aqueous solution. And filtering out the solid of the reaction system, washing the solid with dichloromethane, and recrystallizing to obtain a white solid final product SM-04, wherein the initiator is the compound 1, namely 5-tert-butyl-1, 3-di (2-chloro isopropyl) benzene, and the yield is 92%.

Preparation example 2 preparation of trifunctional initiators (Compounds 21, 22)

(1) In a 1000mL single-neck flask, 18g (0.086mol) of a reactant I in which X is ClC (CH), 500 mL of anhydrous methanol, and 20 mL of concentrated sulfuric acid were charged₃)₂-Y is H, Z is H; the stirring and the circulating cooling water are opened, and the reaction is carried out at room temperature. After the reaction is finished, sealing and standing at low temperature. The product was filtered off with a funnel to give a white solid which was then dried thoroughly to give product II in 90% yield.

(2) Grignard reaction in a 1000mL three-neck flask, 16g (0.063mol) of II was added, 280 mL of THF was added, stirring was started and cooling water was circulated, and the reaction environment was kept under nitrogen atmosphere. 150mL of methyl magnesium bromide was slowly added dropwise to the reaction system by means of a syringe to carry out the reaction. The product was then extracted into a mixture of 280g of crushed ice and 18g of ammonium chloride and dried. Finally, recrystallization provided product iii in 93% yield.

(3) In a 250 mL single-neck flask, 14g of III, 72.5 mL of methanol and 0.0084 mL of concentrated sulfuric acid were added and reacted, after cooling, 100mL of n-hexane was added. The supernatant liquid was washed to neutrality and dried. Finally recrystallizing for several times to obtain a product IV, namely the compound 21, namely the 5-tert-butyl-1, 3-tri (2-chloro isopropyl) benzene, with the yield of 95 percent.

(4) The flask was charged with III and methylene chloride in this order, and dry hydrogen chloride gas was continuously introduced into the reaction system, and the tail gas was slowly absorbed by an aqueous sodium hydroxide solution. Filtering out the solid of the reaction system, washing the solid with dichloromethane, concentrating to obtain a solid, and recrystallizing to obtain a white solid final product V, namely the compound 22 which is 1,3, 5-tri (2-methoxy isopropyl) benzene with the yield of 96%.

Example II

Example 1

A4-liter low-temperature polymerization kettle is adopted, after baking, vacuumizing and nitrogen filling, the temperature is cooled to-70 ℃, methylene dichloride 40ml, hexane 60ml, isobutene 8ml (1.25M), 5ml (0.lM) of 5-tert-butyl-1, 3-di (1-methoxy-1-methyl ethyl) benzene and ethyl benzoate 0.lM are added into the polymerization kettle, and titanium tetrachloride 5ml (0.4M) is added to initiate small-amount isobutene prepolymerization. Then 1.57mL (3M) of a hard segment monomer styrene solution is added into a polymerization system by using a metering pump to control the flow rate (0.1 mL/s) so as to initiate the second segment block polymerization, finally a small amount of methanol is added to terminate the reaction, and then the product is subjected to solvent removal and vacuum drying at 45 ℃ to constant weight so as to obtain the thermoplastic elastomer 1.

Example 2

A4-liter low-temperature polymerization kettle is adopted, after baking, vacuumizing and nitrogen filling, the temperature is cooled to minus 80 ℃, 40ml of methylene dichloride, 60ml of methylcyclohexane, 25 ml of isobutene (1.25M), 5ml of 5-tert-butyl-1, 3-di (1-methoxy-1-methyl-ethyl) benzene (0.l M), 0.l M acetophenone and 0.l M anisole are added into the polymerization kettle, and 5ml of titanium tetrachloride (0.4M) is added to initiate isobutene prepolymerization. Then 2.2mL (3M) of a styrene solution was added to the polymerization system at a controlled flow rate (0.1 mL/s) using a metering pump to initiate the second block polymerization, and finally a small amount of methanol was added to terminate the reaction, after which the product was freed of the solvent and dried under vacuum at 45 ℃ to constant weight to give thermoplastic elastomer 2.

Example 3

A4-liter low-temperature polymerization kettle is adopted, after baking, vacuumizing and nitrogen filling, the temperature is cooled to minus 60 ℃, 40ml of methylene dichloride, 60ml of cyclohexane, 8ml of isobutene (1.25M), 5ml of 5-tert-butyl-1, 3-di (1-methoxy-1-methyl-ethyl) benzene (0.lM), 5ml (0.2M) of 2, 6-di-tert-butylpyridine are added into the polymerization kettle, 5ml (0.2M) of ethyl benzoate is added, and 5ml (0.4M) of titanium tetrachloride is added to initiate isobutene polymerization. Then, 1.57mL (3M) of a styrene solution was added to the polymerization system at a flow rate (0.2 mL/s) controlled by a metering pump to initiate the second-stage block polymerization, and finally, a small amount of methanol was added to terminate the reaction, after which the product was freed of the solvent and vacuum-dried at 45 ℃ to a constant weight to give thermoplastic elastomer 3.

Example 4

A4-liter low-temperature polymerization kettle is adopted, after baking, vacuumizing and nitrogen filling, the temperature is cooled to minus 80 ℃, 300g of methyl chloride, 450g of methylcyclohexane, 20g of isobutene, 0.0034mol of 5-tert-butyl-1, 3-di (1-methoxy-1-methyl-ethyl) benzene, 0.0034mol of ethyl benzoate and 2, 4-dimethylacetophenone are added into the polymerization kettle, 0.11mol of boron trifluoride ether solution is added to initiate a small amount of isobutene prepolymerization, and then 120g of a second part of isobutene is added in batches for continuous reaction. Then 120g of p-tert-butylstyrene solution is added into a polymerization system by using a metering pump to control the flow rate (2 mL/s) so as to initiate second-stage block polymerization, finally a small amount of methanol is added to terminate the reaction, and then the product is subjected to solvent removal and vacuum drying at 45 ℃ to constant weight so as to obtain the thermoplastic elastomer 4.

Example 5

A4-liter low-temperature polymerization kettle is adopted, after baking, vacuumizing and nitrogen filling, the temperature is cooled to-70 ℃, 500g of dichloromethane, 750g of cyclohexane, 50g of isobutene, 0.0062mol of 5-tert-butyl-1, 3-di (1-methoxy-1-methyl-ethyl) benzene, 0.0032mol of dimethyl terephthalate and 0.012mol of 2, 6-di-tert-butylpyridine are added into the polymerization kettle, 0.14mol of boron trichloride ether solution is added to initiate a small amount of isobutene prepolymerization, and then 170g of the second part of isobutene is added in batches for continuous reaction. Then 200g of styrene solution is added into a polymerization system by using a metering pump to control the flow rate (4 mL/s) to initiate second-stage block polymerization, finally a small amount of methanol solution containing ammonia water is added to terminate the reaction, then the solvent of the product is removed, and the product is dried in vacuum at the temperature of 45 ℃ to constant weight, so that the thermoplastic elastomer 5 is obtained.

Example 6

A4-liter low-temperature polymerization kettle is adopted, after baking, vacuumizing and nitrogen filling, the temperature is cooled to 50 ℃ below zero, 115g of methane chloride, 175g of methylcyclohexane, 20g of isobutene, 0.0062mol of 5-tert-butyl-1, 3-di (1-methoxy-1-methyl-ethyl) benzene, 0.0032mol of diethyl phthalate and 0.0032mol of p-tert-butyl ethyl ether are added into the polymerization kettle, 0.14mol of titanium tetrachloride is added to initiate a small amount of isobutene to be prepolymerized, and then 100g of a second part of isobutene is added in batches to continuously react. Then 94g of styrene solution is added into a polymerization system by using a metering pump to control the flow rate (5 mL/s) to initiate second-stage block polymerization, finally a small amount of methanol solution containing ammonia water is added to terminate the reaction, then the solvent of the product is removed, and the product is dried in vacuum at the temperature of 45 ℃ to constant weight, so that the thermoplastic elastomer 6 is obtained.

Example 7

A4-liter low-temperature polymerization kettle is adopted, after baking, vacuumizing and nitrogen filling, the temperature is cooled to minus 90 ℃, 500g of methane chloride, 750g of cyclohexane, 50g of isobutene, 0.0072mol of 1,3, 5-triisopropylchlorobenzene, 0.012mol of acetophenone and 0.0062mol of 2, 6-di-tert-butyl-4-methylpyridine are added into the polymerization kettle, 0.186mol of titanium tetrachloride is added to initiate a small amount of isobutene to be prepolymerized, and 170g of a second part of isobutene is added in batches to continuously react for 70 min. Then 270g of p-methylstyrene solution was added to the polymerization system at a controlled flow rate (2 mL/s) using a metering pump to initiate the second block polymerization, and finally a small amount of methanol was added to terminate the reaction, after which the product was freed from the solvent and dried under vacuum at 45 ℃ to constant weight to give thermoplastic elastomer 7.

Example 8

A4-liter low-temperature polymerization kettle is adopted, after baking, vacuumizing and nitrogen filling, the temperature is cooled to minus 80 ℃, 130g of methylene dichloride, 300g of methylcyclohexane, 20g of isobutene, 0.0034mol of 1,3, 5-tri (1-methoxy-1-methyl-ethyl) benzene (namely the compound 22 in the preparation example 2) and 0.0012mol of phenetole are added into the polymerization kettle, 0.136mol of ferric chloride is added to initiate prepolymerization of a small amount of isobutene, and then 90g of a second part of isobutene is added in batches to continue reaction. 185g of a p-ethylstyrene solution was then added to the polymerization system at a controlled flow rate (2 mL/s) using a metering pump to initiate the second stage of block polymerization, and finally a small amount of methanol was added to terminate the reaction, after which the product was freed of solvent and dried under vacuum at 45 ℃ to constant weight to give thermoplastic elastomer 8.

Example 9

A4-liter low-temperature polymerization kettle is adopted, after baking, vacuumizing and nitrogen filling, the temperature is cooled to 50 ℃ below zero, 160g of dichloromethane, 240g of cyclohexane, 30g of isobutene, 0.003mol of 5-tert-butyl-1, 3-di (2-chloro isopropyl) benzene (namely the compound 1 of the preparation example 1) and 0.0017mol of 2, 6-di-tert-butylpyridine are added into the polymerization kettle, 0.0017mol of phenetole are added, 0.096mol of ferric chloride is added to initiate a small amount of isobutene to be prepolymerized, and then 70g of a second part of isobutene is added in batches for continuous reaction. 130g of styrene solution is added into a polymerization system by using a metering pump to control the flow rate (2 mL/s) to initiate second-stage block polymerization, a small amount of methanol is added to terminate the reaction, and then the product is subjected to solvent removal and vacuum drying at 45 ℃ to constant weight to obtain the thermoplastic elastomer 9.

Example 10

A4-liter low-temperature polymerization kettle is adopted, after baking, vacuumizing and nitrogen filling, the temperature is cooled to minus 60 ℃, 240g of methane chloride, 240g of methylcyclohexane, 25g of isobutene and 0.0025mol of trifunctional initiator 1,3, 5-tri (2-chloro isopropyl) benzene (namely the compound 21 in the preparation example 2), 0.0012mol of anisole, 0.0012mol of benzophenone and 0.002mol of 2,4, 6-tri-tert-butyl pyridine are added into the polymerization kettle, 0.096mol of boron trifluoride ether solution is added to initiate a small amount of isobutene to be prepolymerized, and 80g of second part of isobutene is added to continuously react. Then 160g of p-tert-butylstyrene solution is added into the polymerization system by using a metering pump to control the flow rate (2 mL/s) so as to initiate the second-stage block polymerization, finally a small amount of methanol is added to terminate the reaction, and then the product is subjected to solvent removal and vacuum drying at 45 ℃ to constant weight so as to obtain the thermoplastic elastomer 10.

Example 11

A4-liter low-temperature polymerization kettle is adopted, after baking, vacuumizing and nitrogen filling, the temperature is cooled to minus 80 ℃, 400g of methylene dichloride, 930g of methylcyclohexane, 50g of isobutene, 0.0062mol of 5-tert-butyl-1, 3-di (1-methoxy-1-methyl-ethyl) benzene and 0.0032mol of methyl benzoate are added into the polymerization kettle, 0.14mol of boron trichloride ether solution is added to initiate a small amount of isobutene to be prepolymerized, and then 170g of a second part of isobutene is added in batches for continuous reaction. Then 200g of alpha-methyl styrene solution is added into a polymerization system by using a metering pump to control the flow rate (4 mL/s) to initiate second-stage block polymerization, finally a small amount of methanol solution containing ammonia water is added to terminate the reaction, and then the product is subjected to solvent removal and vacuum drying at 45 ℃ to constant weight to obtain the thermoplastic elastomer 11.

Example 12

A4-liter low-temperature polymerization kettle is adopted, after baking, vacuumizing and nitrogen charging, the temperature is cooled to-70 ℃, 400g of methylene dichloride, 930g of methylcyclohexane, 60g of isobutene, 0.0062mol of 5-tert-butyl-1, 3-bis (1-methoxy-1-methyl-ethyl) benzene, 0.005mol of phenetole and 0.005mol of ethyl phenylacetate are added into the polymerization kettle, 0.14mol of boron trifluoride ether solution is added to initiate a small amount of isobutene prepolymerization, and then 170g of the second part of isobutene is added in batches for continuous reaction. Then 200g of styrene solution is added into a polymerization system by using a metering pump to control the flow rate (2 mL/s) to initiate second-stage block polymerization, finally a small amount of methanol solution containing ammonia water is added to terminate the reaction, then the solvent of the product is removed, and the product is dried in vacuum at the temperature of 45 ℃ to constant weight, so that the thermoplastic elastomer 12 is obtained.

Example 13

A4-liter low-temperature polymerization kettle is adopted, after baking, vacuumizing and nitrogen filling, the temperature is cooled to-70 ℃, n-hexane/dichloromethane with the volume ratio of 60/40 is added as a solvent of 100ml, the mixture is uniformly mixed, 2ml of isobutene, 5ml (0.l M) of 5-tert-butyl-1, 3-di (2-chloro isopropyl) benzene (namely the compound 1 of the preparation example 1) and 5ml of diisooctyl phthalate are added into the polymerization kettle, 5ml (0.4M) of boron trichloride ether solution is added to initiate isobutene prepolymerization, and then 6ml of a second part of isobutene is added in batches for continuous reaction. Then, 1.57mL (3M) of hard segment monomer styrene and 0.16mL (0.3M) of 4-vinylbenzocyclobutene were added to the polymerization system at a flow rate (0.1 mL/s) controlled by a metering pump to initiate the second-segment block polymerization, and finally, precooled methanol containing a small amount of aqueous ammonia solution was added to terminate the polymerization, after which the product was freed from the solvent and dried in vacuum at 45 ℃ to constant weight, to obtain a thermosetting elastomer 13.

Example 14

A4-liter low-temperature polymerization kettle is adopted, after baking, vacuumizing and nitrogen filling, the temperature is cooled to minus 80 ℃, 200g of dichloromethane, 300g of methylcyclohexane, 25g of isobutene, 0.003mol of trifunctional initiator 1,3, 5-tri (2-chloro isopropyl) benzene, 0.0015mol of diisooctyl phthalate and 0.0015mol of acetophenone are added into the polymerization kettle, 0.14mol of boron trifluoride ether solution is added to initiate small amount of isobutene prepolymerization, and then 160g of second part of isobutene is added in batches for continuous reaction. And then adding 170g of styrene and 50g of 4-vinylbenzocyclobutene solution into a polymerization system at a flow rate (1.5 mL/s) controlled by a metering pump to initiate second-stage block polymerization, adding precooled methanol containing a small amount of ammonia solution to terminate the polymerization, removing the solvent from the product, and drying the product in vacuum at 45 ℃ to constant weight to obtain the thermosetting elastomer 14.

Example 15

A4-liter low-temperature polymerization kettle is adopted, after baking, vacuumizing and nitrogen filling, the temperature is cooled to minus 80 ℃, 300g of methane chloride, 300g of methylcyclohexane, 25g of isobutene, 0.003mol of trifunctional initiator 1,3, 5-tri (2-chloro isopropyl) benzene, 0.0015mol of anisole and 0.0015mol of acetophenone are added into the polymerization kettle, 0.14mol of titanium tetrachloride is added to initiate a small amount of isobutene to be prepolymerized, and then 160g of a second part of isobutene is added in batches for continuous reaction. Then 40g of styrene and 14g of 4-vinylbenzocyclobutene solution are added into a polymerization system at a flow rate (1.5 mL/s) controlled by a metering pump to initiate second-stage block polymerization, and finally precooled methanol containing a small amount of ammonia solution is added to terminate the polymerization, and then the solvent is removed from the product, and the product is dried in vacuum at 45 ℃ to constant weight to obtain the thermosetting elastomer 15.

Example 16

A4-liter low-temperature polymerization kettle is adopted, after baking, vacuumizing and nitrogen filling, the temperature is cooled to minus 80 ℃, 300g of dichloromethane, 300g of cyclohexane, 30g of isobutene, 0.003mol of 5-tert-butyl-1, 3-di (2-chloro isopropyl) benzene, 0.002mol of anisole and 0.002mol of dibutyl terephthalate are added into the polymerization kettle, 0.14mol of ferric trichloride is added to initiate a small amount of isobutene to be prepolymerized, and then 160g of a second part of isobutene is added in batches for continuous reaction. And then adding 45g of styrene and 20g of 4-vinylbenzocyclobutene solution into a polymerization system at a flow rate (1.5 mL/s) controlled by a metering pump to initiate second-stage block polymerization, adding precooled methanol containing a small amount of ammonia solution to terminate the polymerization, removing the solvent from the product, and drying the product in vacuum at 45 ℃ to constant weight to obtain the thermosetting elastomer 16.

Comparative example III

Comparative example 1a

Pumping cold liquid into a vacuum glove box, cooling to the polymerization temperature of-70 ℃, adding 100ml of n-hexane/dichloromethane serving as a solvent with the volume ratio of 60/40 into a treated polymerization bottle, and uniformly mixing; then theAdding an initiator system formed by aging 5ml (0.lM) of a main initiator 5-tert-butyl-1, 3-bis (1-methoxy-1-methylethyl) benzene, 5ml (0.4M) of a co-initiator titanium tetrachloride and 5ml (0.2M) of a third component EtOAc (0.2M), adding 8ml (1.25M) of middle-stage monomer isobutene after aging for 5min, adding 1.57ml (3M) of hard-stage monomer styrene after reacting for 45-60 min, continuing to react for 90min, and finally adding methanol (CH) based on the termination of the reaction₃OH), removing the solvent from the product after the reaction is stopped, and drying the product in vacuum at the temperature of 45 ℃ to constant weight.

Comparative example 2b

Pumping cold liquid into a vacuum glove box, cooling to the polymerization temperature of-80 ℃, adding 100ml of n-hexane/dichloromethane serving as a solvent with the volume ratio of 40/60 into a treated polymerization bottle, and uniformly mixing; then adding 5ml (0.l M) of main initiator 5-tert-butyl-1, 3-bis (1-methoxy-1-methylethyl) benzene, 5ml (0.4M) of co-initiator titanium tetrachloride and 5ml (0.2M) of proton scavenger DTBP (2, 6-di-tert-butylpyridine) to age the initiator system, adding 25 ml (1.25M) of middle-segment monomer isobutene after aging for 15min, adding 2.2ml (3M) of hard-segment monomer styrene after reacting for 45-60 min, continuing to react for 90min, and finally adding methanol (CH) based on the termination of the reaction₃OH), removing the solvent from the product after the reaction is stopped, and drying the product in vacuum at the temperature of 45 ℃ to constant weight.

Comparative example 3c

Pumping cold liquid into a vacuum glove box, cooling to the polymerization temperature of-80 ℃, adding 100ml of n-hexane/dichloromethane serving as a solvent with the volume ratio of 60/40 into a treated polymerization bottle, and uniformly mixing; then adding an initiator system formed by aging 5ml (0.l M) of a main initiator 5-tert-butyl-1, 3-bis (2-methoxy-1-methylethyl) benzene, 5ml (0.4M) of a co-initiator titanium tetrachloride and 5ml (0.2M) of a proton scavenger DTBP, adding 8ml (1.25M) of intermediate-segment monomer isobutene after aging for 5min, adding 1.57ml (3M) of hard-segment monomer styrene after reacting for 45-60 min, continuing to react for 90min, and finally adding methanol (CH) based on the termination of the reaction₃OH), removing the solvent from the product after the reaction is stopped, and drying the product in vacuum at the temperature of 45 ℃ to constant weight.

Comparative example 13d

Pumping into a vacuum glove boxCooling the liquid to-70 deg.c, adding 60/40 vol n-hexane/dichloromethane as solvent 100ml into the treated polymerization bottle and mixing; then adding 5ml (0.l M) of main initiator 5-tert-butyl-1, 3-bis (2-methoxy-1-methylethyl) benzene, 5ml (0.4M) of co-initiator boron trifluoride ether solution and 5ml (0.2M) of proton scavenger DTBP for aging to form an initiator system, adding 8ml (1.25M) of intermediate-segment monomer isobutene after aging for 5min, adding 1.57ml (3M) of hard-segment monomer styrene and 0.16ml (0.3M) of 4-vinylbenzocyclobutene after reacting for 45-60 min, continuing to react for 90min, and finally adding methanol (CH) based on reaction termination₃OH), removing the solvent from the product after the reaction is stopped, and drying the product in vacuum at the temperature of 45 ℃ to constant weight.

The test conditions and results of the above examples and comparative examples are summarized in the following tables 1,2 and 3:

TABLE 1

TABLE 2

TABLE 3

Examples/comparative examples	Elongation at break%	Ultimate tensile strength MPa
			Example 1	793	20.1
Comparative example 1a	602	15.5
			Example 2	589	19.6
Comparative example 2b	550	16.1
			Example 3	700	18.2
Comparative example 3c	603	17.8
			Example 4	724	18.8
Example 5	662	16.3
			Example 6	761	19.6
Example 7	635	15.6
			Example 8	540	14.5
Example 9	610	14.8
			Example 10	520	14.2
Example 11	630	19.2
			Example 12	665	20.9
Example 13	698	21.2
			Comparative example 13d	563	17.6
Example 14	682	21.8
			Example 15	320	9.6
Example 16	342	10.5

As can be seen from the above experimental data, the present invention provides a method for preparing polyisobutylene-soft block copolymer, i.e., thermoplastic/thermosetting elastomer, by a living/controllable cationic polymerization system and an initiator system in a batch feeding manner. In the preparation method, the polymerization of the first part of the low-concentration isobutene is initiated to form a stable primary active center; followed by the addition of a second portion of the isobutylene monomer to produce a polyisobutylene containing multiple living chain ends, followed by the addition of styrene and its derivatives to produce a linear or three-armed radial polystyrene-isobutylene-styrene triblock copolymer (SIBS), a linear or three-armed radial poly (styrene-co-block-4-vinylbenzocyclobutene) -polyisobutylene-poly (styrene-co-block-4-vinylbenzocyclobutene) triblock copolymer (xsibss).

And testing the polymer according to the determination of the gel content of the raw rubber synthesized by the petrochemical industry standard SH/T1050-2014 of the people's republic of China, wherein the mass percent of the gel in the copolymer prepared by the embodiment of the invention is less than 5 percent.

The above examples effectively avoid severe chain transfer and chain termination reactions due to excessive exothermic concentration by adding isobutylene in batches, thereby obtaining linear or three-armed star polymers with controlled molecular structures.

The embodiment of the invention adopts an initiator system to synthesize the thermoplastic/thermosetting elastomer, and can form a stable primary active center. The initiator system comprises a main initiator, a co-initiator, a third component and a proton scavenger, wherein the main initiator comprises a bifunctional group or a polyfunctional group. In the above embodiment, the third component is added to the initiator system to stabilize the active center, so as to effectively reduce the gel content in the copolymer, and improve the conversion rate of the styrene and the derivatives thereof participating in the reaction (the conversion rate of the second monomer reaches 50wt% to 100 wt%), thereby forming a stable linear and star polymer structure. In the polymerization preparation process, different mechanical properties can be obtained by changing the feeding ratio of the first monomer/the second monomer and the relative molecular mass, and the obtained product has narrow molecular weight distribution.

The invention also provides a new method for preparing the main initiator by improving the process conditions, solves the potential danger of easy explosion caused by contact of the solvent and air in the traditional format reaction, and promotes the complete conversion of the product. In the preparation method of the main initiator, the purification process of the intermediate product in each process further improves the problem of difficult preparation and post-treatment processes, greatly improves the production efficiency, and successfully enlarges the preparation process of the main initiator to the scale meeting the industrial production level. By developing a series of novel initiator derivatives, the initiator for cationic polymerization with higher initiation efficiency and high purity is prepared, and the linear or three-arm star polymer with controllable molecular structure can be synthesized by using the initiator.

The copolymer can be used for preparing raw materials of controlled drug release, external catheters, implant stents and the like, such as ophthalmic implant materials, vascular stent coatings, glaucoma catheters, artificial blood vessels and heart valves.

The above description is directed to exemplary embodiments of the present invention. However, the scope of protection of the present application is not limited to the above-described embodiments. Any modification, equivalent replacement, improvement and the like made by those skilled in the art within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A copolymer prepared by copolymerizing a first monomer and a second monomer under an initiator system, characterized in that:

said first monomer is selected from isomonoolefins and said second monomer comprises monomer a and optionally monomer B, either present or absent;

the monomer A is selected from one, two or more of the following compounds: styrene; by one or more C_1-10Alkyl substituted styrenes; styrene substituted with one or more halogens; by one or more monohaloalkyl or polyhaloC_1-10Alkyl substituted styrenes;

the monomer B is selected from phenyl and C_4-8Cycloalkenyl-fused styrenes;

the molar ratio of the monomer A to the monomer B is (80-100) to (0-20);

in the copolymer, the total content of the second monomer is 5-50 wt%;

in the copolymer, the mass percent of gel is less than 5 wt%.

2. The copolymer of claim 1, wherein:

the first monomer is selected from isobutylene;

the monomer A is selected from styrene, alpha-methyl styrene, p-methyl styrene, m-methyl styrene, p-ethyl styrene, p-tert-butyl styrene, p-chlorostyrene, p-bromostyrene, p-chloromethyl styrene and p-bromomethyl styrene;

the monomer B is selected from 4-vinylbenzocyclobutene;

the molar ratio of the monomer A to the monomer B is (90-100) to (0-10);

in the copolymer, when the monomer A exists and the monomer B does not exist, the total content of the second monomer is 20-50 wt%;

when the monomer A, B is present simultaneously, the second monomer content is 5wt% to 50 wt%;

in the copolymer, the mass percent of gel is less than 3 wt%.

3. The copolymer of claim 1 or 2, wherein:

the Mn of the copolymer was 4.0X 10³To 5.0X 10⁵The molecular weight of the first single body section is 0.2-40 ten thousand, and the molecular weight of the second single body section is 0.2-30 ten thousand;

the copolymer has a molecular weight distribution coefficient Mw/Mn of 1.10-2.50.

4. The copolymer of claim 1 or 2, wherein: the copolymer is selected from the structures represented by formulas (i), (ii), (iii) or (iv):

wherein each x is the same or different and is independently selected from a number of 40-7000;

each y is the same or different and is independently selected from a number of 20 to 3000;

each m is the same or different and is independently selected from a number from 0 to 10.

5. Process for the preparation of the copolymers according to any of claims 1 to 4, characterized in that: the preparation method comprises the steps of adding a first monomer to an initiator system in batches under the initiator system to initiate polymerization, and then adding a second monomer to perform copolymerization to prepare the copolymer;

the temperature of the copolymerization reaction is-100 ℃ to-50 ℃;

the initiator system comprises a primary initiator or a combination of a primary initiator and a co-initiator, and optionally a third component and/or a proton scavenger;

the primary initiator has a structure represented by the following formula (A):

（A）

wherein X is selected from tert-butyl, isopropyl, methoxy, 2-methoxyisopropyl, 2-chloroisopropyl, NO₂Cl, Br, I or H;

z is selected from H, NO₂Or a tert-butyl group;

r is selected from Cl, methyl or methoxy;

the coinitiator is selected from at least one of titanium tetrachloride, ferric chloride, boron trifluoride, boron trichloride, gallium trichloride, aluminum chloride and alkyl aluminum chloride;

the third component is at least one of aromatic ester, aromatic ether or aromatic ketone;

the proton scavenger is selected from tertiary amine compounds.

6. The method of claim 5, wherein:

the aromatic ketone is selected from at least one of benzophenone, acetophenone, 2, 4-dimethylacetophenone and phenyl acetone;

the aromatic ether is selected from at least one of anisole, phenetole, diphenyl ether, p-ethyl phenetole, n-butylphenyl ether and p-tert-butyl phenetole;

the aromatic ester is selected from at least one of methyl benzoate, ethyl phenylacetate, dimethyl terephthalate, diethyl terephthalte, diethyl isophthalate, diethyl phthalate, dibutyl terephthalate, diethyl 2, 6-dimethyl terephthalate, dimethyl phthalate, diethyl phthalate and diisooctyl phthalate;

the proton scavenger is selected from substituted or unsubstituted tertiary aromatic amine compounds.

7. The method of claim 5, wherein:

adding a first part of a first monomer into the initiator system, adding a second part of the first monomer, and then adding a second monomer to prepare the copolymer;

the first portion of the first monomer accounts for less than 40wt% of the total mass of the first monomer.

8. The method of claim 5, wherein:

the mass fraction of the sum of the first monomer and the second monomer in the total reaction system is 5-45 wt%;

the molar ratio of the main initiator to the first monomer is 1 (40-7000);

when the coinitiator exists, the molar ratio of the main initiator to the coinitiator is 1 (2-50);

when the third component is present, the molar ratio of the third component to the main initiator is (0-10) to 1;

when the proton scavenger is present, the molar ratio of the proton scavenger to the main initiator is (0-5): 1.

9. The method according to claim 8, wherein the method is carried out in the presence of a solvent selected from at least one of chloroalkanes, methylcyclohexane, or cyclohexane.

10. Use of a copolymer according to any of claims 1 to 4 as an elastomer in asphalt modifiers, medical materials, 5G optical fibre protective layers or hot melt adhesives.

11. The use according to claim 10, wherein the medical material is selected from the group consisting of glaucoma catheters, intracorneal contact lenses, intraocular lenses, drug delivery vehicles, vascular grafts, and tissue fillers.