Functional group migration free radical copolymerization method and polymer thereof

Abstract

The invention discloses a functional group migration free radical copolymerization reaction method and a polymer thereof, and belongs to the technical field of polymer polymerization. A first polymeric monomer A and an initiator are mixed and react to obtain primary free radicals, then a second polymeric monomer B is added, and the second polymeric monomer B and the first polymeric monomer A are subjected to a copolymerization reaction to obtain the polymer. In the polymerization process, the polarity of the polymeric monomers and the reaction conditions such as the feeding ratio and the feeding sequence of the comonomers are regulated and controlled, so that two or more polymeric monomers can be controlled to obtain a series of polymers which are clear in structure, narrow in molecular weight distribution and few in branched chains through the copolymerization reaction; moreover, the reaction conditions are simple and easy to control, the technical problems that the polymerization process of various different polymeric monomers is difficult to control, the reaction process is complicated, and the obtained polymer is relatively wide in molecular weight distribution, serious in branching, random in structure and unstable can be solved, and the method has potential application value.

Description

Technical Field

[0001] This invention relates to the field of polymer polymerization technology, and more particularly to a method for functional group migration radical copolymerization and its polymer. Background Art

[0002] In chain reactions, polymerization involving two or more monomers is called binary copolymerization or multi-component copolymerization. The product is a multi-component copolymer. Copolymerization of multiple monomers can improve the structural properties of macromolecules, increase variety, and expand the range of applications. However, it is difficult to control the reaction process when polymerizing two or more monomers, resulting in unstable polymer structures with many branches. For example, polymers obtained through free radical copolymerization of two or more monomers exhibit a wide molecular weight distribution and severe branching due to chain transfer reactions. Furthermore, because the reaction rates of the various monomers differ, the resulting polymers are generally random copolymers, making it difficult to achieve ordered copolymerization and obtain polymers with defined structures. Moreover, due to the rapid development of society, industry, and manufacturing, traditional materials and monomers are no longer sufficient to meet the demands of modern society, necessitating new polymerization methods and novel monomers to construct high-performance polymers. Summary of the Invention

[0003] The main objective of this invention is to provide a method for functional group migration free radical copolymerization and its polymer, thereby solving the technical problems of difficulty in controlling the reaction process when two or more monomers are polymerized, and the resulting polymer having a wide molecular weight distribution, severe branching, and random and unstable structure.

[0004] To achieve the above objectives, the present invention provides a method for functional group migration radical copolymerization, comprising the following steps:

[0005] Step 1: Mix the initiator and the first monomer A, and heat the mixture to obtain the reaction mother liquor;

[0006] Step 2: Add the second monomer B dropwise to the mother liquor of the reaction, heat the reaction to obtain a reaction solution, and precipitate the reaction solution in an organic solvent to obtain a polymer;

[0007] in,

[0008] The initiator includes compounds that can generate free radicals under light and / or heat conditions;

[0009] The first polymerizable monomer A comprises an olefin compound containing four or more carbon atoms, and includes electron-donating groups and electron-withdrawing groups that can migrate.

[0010] The second polymerizable monomer B includes an electron-deficient olefin compound.

[0011] In some embodiments of the present invention, the electron-withdrawing groups that can migrate in the first polymeric monomer A include benzofuran, benzothiophene, thiophene, oxazole, -CN, -SO2Ph, -NO2, etc.

[0012] And / or, the electron-donating group in the first polymeric monomer A includes phenyl or alkyl groups;

[0013] And / or, the second polymerizable monomer B includes at least one of acrylonitrile, acrylate compounds, methacrylates, acrylic acid, or acrylamide compounds;

[0014] And / or, the initiator includes at least one of organic peroxides and azo compounds;

[0015] And / or, the organic solvent includes at least one of ethanol, acetonitrile, acetone, dimethyl sulfoxide, N,N-dimethylformamide, ethyl acetate, N-methylpyrrolidone, toluene, dimethyl sulfoxide, and chlorobenzene.

[0016] In some embodiments of the present invention, the first polymeric monomer A has the following general structural formula:

[0017]

[0018] in,

[0019] n≥1 in the first polymerizable monomer A;

[0020] R1 in the first polymeric monomer A includes a migratable electron-withdrawing group or an electron-donating group;

[0021] R2 in the first polymeric monomer A includes a migratable electron-withdrawing group or an electron-donating group;

[0022] And / or,

[0023] The second polymerizable monomer B has the following general structural formula:

[0024]

[0025] in,

[0026] R3 in the second polymer monomer B includes an electron-withdrawing group.

[0027] In some embodiments of the present invention, the organic peroxide includes at least one of acyl peroxides, hydrogen peroxides, dialkyl peroxides, ester peroxides, ketone peroxides, and dicarbonate peroxides;

[0028] And / or, the azo compounds include at least one of azobisisobutyronitrile, azobisisoheptanenitrile, azobisisovalerate, azobiscyclohexylformitrile, and dimethyl azobisisobutyrate.

[0029] In some embodiments of the present invention, the organic peroxide is an acyl peroxide, which includes at least one of benzoyl peroxide and lauroyl peroxide;

[0030] And / or, the organic peroxide is a hydrogen peroxide, and the hydrogen peroxide includes at least one of cumene hydrogen peroxide and tert-butyl hydrogen peroxide;

[0031] And / or, the organic peroxide is a dialkyl peroxide, which includes at least one of di-tert-butyl peroxide and dicumyl peroxide;

[0032] And / or, the organic peroxide is an ester peroxide, which includes at least one of tert-butyl peroxide and tert-butyl peroxide;

[0033] And / or, the organic peroxide is a ketone peroxide, which includes at least one of methyl ethyl ketone peroxide and cyclohexanone peroxide;

[0034] And / or, the organic peroxide is a dicarbonate peroxide, which includes at least one of diisopropyl peroxide and dicyclohexyl peroxide.

[0035] In some embodiments of the present invention, the molar ratio of the first polymeric monomer A to the initiator is in the range of 100:(1-50);

[0036] And / or, the molar ratio of the first polymeric monomer A and the second polymeric monomer B is in the range of 3:(3 to 10); or, the molar ratio of the first polymeric monomer A and the second polymeric monomer B is in the range of (3 to 10):3.

[0037] In some embodiments of the present invention, in step one, the temperature range of the heating reaction is 45°C to 150°C;

[0038] And / or, in step one, the heating reaction time is greater than or equal to 0.5 h;

[0039] And / or, in step two, the temperature range of the heating reaction is 45°C to 150°C;

[0040] And / or, in step two, the heating reaction time is greater than or equal to 1 hour;

[0041] And / or, the heating reaction in step one and the heating reaction in step two are carried out in a protective atmosphere or air, the protective atmosphere including nitrogen or argon;

[0042] And / or, in step one, the first polymerizable monomer A and the initiator are dissolved and mixed in an organic solvent;

[0043] And / or, in step one, the first polymeric monomer A and the initiator are dissolved and mixed in an organic solvent, and the amount of the first polymeric monomer A added is (3-10) mmol / mL, based on the volume of the organic solvent in mL.

[0044] And / or, in step one, the first polymerization monomer A and the initiator are dissolved and mixed in an organic solvent, the organic solvent including at least one of ethanol, acetonitrile, acetone, dimethyl sulfoxide, N,N-dimethylformamide, ethyl acetate, N-methylpyrrolidone, toluene, dimethyl sulfoxide, and chlorobenzene.

[0045] The present invention also provides a polymer prepared by the method described above for functional group migration radical copolymerization.

[0046] In some embodiments, the polymer has a molecular weight of 1000 or higher;

[0047] And / or, the distribution width (PDI) of the polymer is 1.10-4.00;

[0048] And / or, the conversion rate of the first polymeric monomer A is 10%-90%;

[0049] And / or, the conversion rate of the second polymerizable monomer B is 10%-90%.

[0050] In some embodiments, the polymer has the following general structural formula:

[0051]

[0052] R1 includes an electron-donating group, R2 includes a migratable electron-withdrawing group, R3 includes a migratable electron-withdrawing group, and n, x, and y are all greater than or equal to 1.

[0053] In some embodiments, the polymer has the following structural formula (Ⅰ):

[0054] Where x and y are both greater than or equal to 1; or,

[0055] It has the following structural formula (II):

[0056] Where x and y are both greater than or equal to 1; or,

[0057] It has the following structural formula (Ⅲ):

[0058] Where x and y are both greater than or equal to 1; or,

[0059] It has the following structural formula (Ⅳ):

[0060] Where x and y are both greater than or equal to 1; or,

[0061] It has the following structural formula (V):

[0062] Where x and y are both greater than or equal to 1; or, it has the following structure (VI):

[0063] Where x and y are both greater than or equal to 1; or, it has the following structure (Ⅶ):

[0064] Where x and y are both greater than or equal to 1; or

[0065] It has the following structural formula (VIII):

[0066] Where x and y are both greater than or equal to 1; or, it has the following structure (IX):

[0067] Where x and y are both greater than or equal to 1.

[0068] In some embodiments of the present invention

[0069] The structural formula (Ⅰ) is as follows: n is greater than or equal to 1;

[0070] And / or, the structural formula (II) is as follows: n is greater than or equal to 1;

[0071] And / or, the structural formula (Ⅲ) is as follows: n is greater than or equal to 1;

[0072] And / or, the structural formula (Ⅳ) is as follows: n is greater than or equal to 1;

[0073] And / or, the structural formula (V) is as follows: n is greater than or equal to 1;

[0074] And / or, the structural formula (VI) is as follows: n is greater than or equal to 1;

[0075] And / or, the structural formula (VII) is as follows: n is greater than or equal to 1;

[0076] And / or, the structural formula (VIII) is as follows: n is greater than or equal to 1;

[0077] And / or, the structural formula (IX) is as follows: n is greater than or equal to 1.

[0078] The beneficial effects that this invention can achieve are:

[0079] This invention selects an olefin compound containing four or more carbon atoms and having both migratable electron-withdrawing and electron-donating groups as the first polymerizing monomer A, and an olefin compound with electron-deficient characteristics as the second polymerizing monomer B. Using the first polymerizing monomer A as the basis for the polymerization reaction, it reacts with an initiator to allow the migratable electron-withdrawing groups to migrate to carbon atoms at the distal end of the main chain, providing reaction sites for the subsequent introduction of the second polymerizing monomer B. Furthermore, a primary active free radical is formed. Because this primary active free radical is connected to the electron-donating group, it possesses nucleophilicity. This nucleophilic free radical cannot undergo an addition reaction with the electron-rich first polymerizing monomer A, but readily undergoes a polymerization reaction with the second polymerizing monomer B, which has an electron-deficient carbon-carbon double bond. This forms a new electrophilic free radical, which in turn promotes the continued polymerization of either the first polymerizing monomer A or the second polymerizing monomer B. This achieves the polymerization between the second polymerizing monomer B and the first polymerizing monomer A, resulting in a series of polymers with few branches and stable structures.

[0080] This invention utilizes functional group transfer radical polymerization to regulate the polarity of the polymer during the polymerization process. This allows for the controlled polymerization of two or more different monomers to obtain a series of polymers with stable and ordered structures and narrow molecular weight distributions. Furthermore, random copolymers can be obtained by adjusting the feed ratio and feed sequence of the monomers. Moreover, the reaction conditions are simple and easy to control, solving the technical problems of difficult-to-control polymerization processes of multiple different monomers, complex reaction processes, and polymers with many branches and unstable structures. Attached Figure Description

[0081] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art are briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without creative effort.

[0082] Figure 1This is a schematic diagram of a functional group migration radical copolymerization reaction according to an embodiment of the present invention. Figure 2 The image shows the proton NMR spectrum of the polymer obtained in Example 1 of this invention.

[0083] The realization of the objective, functional features and advantages of the present invention will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. DETAILED DESCRIPTION

[0084] It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

[0085] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without making any creative efforts shall fall within the scope of protection of the present invention.

[0086] In this invention, the terms "first," "second," etc., are used for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined with "first" or "second" may explicitly or implicitly include at least one of that feature. Furthermore, the technical solutions of the various embodiments can be combined with each other, but only on the basis of being achievable by those skilled in the art. If the combination of technical solutions is contradictory or impossible to implement, such a combination of technical solutions should be considered non-existent and not within the scope of protection claimed by this invention.

[0087] This invention provides a method for polymerizing functional group migrating radicals, comprising the following steps:

[0088] Step 1: Mix the initiator and the first monomer A, and heat the mixture to obtain the reaction mother liquor;

[0089] Step 2: Add the second monomer B dropwise to the mother liquor, heat to obtain a reaction solution, and precipitate the reaction solution in an organic solvent to obtain the polymer. The initiator includes compounds that can generate free radicals under light and / or heat conditions. The first monomer A includes an olefin compound containing four or more carbon atoms and including electron-donating and electron-withdrawing groups. The second monomer B includes an electron-deficient olefin compound.

[0090] It should be noted that the presence of four or more carbon atoms in the first monomer A can be understood as the olefin compound having at least four carbon atoms in its main chain. The presence of at least four carbon atoms in the main chain of the first monomer A facilitates the migration of electron-withdrawing groups to the distal carbon atoms of the main chain via functional group migration radicals, thus completing the polymerization reaction. Simultaneously, it provides reaction sites for the polymerization of the second monomer B, enabling the polymerization of two or more monomers to form a novel polymer.

[0091] This invention utilizes a free radical migration reaction to complete the polymerization of free radicals. In the reaction process, a primary active free radical is obtained by reacting a first monomer A with an initiator. This newly formed free radical is nucleophilic, and the nucleophilic free radical readily reacts with the double bond in the electron-deficient olefin compound, the second monomer B, to generate a new electrophilic free radical. The electrophilic free radical readily undergoes an addition reaction with either the first monomer A or the second monomer B, thereby forming new free radicals and creating reaction conditions for further polymerization. In this way, the second monomer B and the first monomer A undergo a polymerization reaction to ultimately form a series of polymers. The resulting polymers have few branches, stable structures, and simple and controllable reaction conditions.

[0092] This invention provides an embodiment to explain the reaction mechanism of the above-described polymerization method based on functional group migrating free radicals. However, it should be noted that the following embodiment is only one embodiment of the technical solution of this invention and does not constitute a limitation on the technical solution of this invention.

[0093] In this embodiment, the monomers undergoing the polymerization reaction are a first monomer A and a second monomer B. The structural formula of the first monomer A is as follows: The second monomer B contains an electron-donating group R1 and a migratable electron-withdrawing group R2, and n is greater than or equal to 1. Its structural formula is as follows: The polymerization process, which involves the use of electron-withdrawing groups R3 and the generation of free radicals X· by the initiator under light and / or heat conditions, is as follows:

[0094] A free radical X· is generated by an initiator and undergoes an addition reaction with the first monomer A. The electron-withdrawing group R2 in monomer A migrates to the carbon atom at the distal end of the main chain, forming a primary active free radical b, which provides a reaction site. This free radical b is nucleophilic and readily undergoes an addition reaction with the double bonds in electron-deficient olefin compounds. The second monomer B is precisely an electron-deficient olefin compound with carbon-carbon double bonds. Therefore, free radical b can initiate a new round of addition reactions in the second monomer B, generating an electrophilic free radical c. This electrophilic free radical c readily undergoes an addition reaction with the first monomer A to regenerate the nucleophilic free radical b, providing conditions for further polymerization with the second monomer B. This invention achieves stable ordered or random polymer structures with fewer branches by adjusting the polarity of the polymer during polymerization, and the entire reaction process is easily controlled.

[0096] In some embodiments, the first polymeric monomer A has the following general structural formula:

[0097]

[0098] In this embodiment, R1 in the first polymerizable monomer A is a migratory electron-withdrawing or electron-donating group, and R2 in the first polymerizable monomer A is a migratory electron-withdrawing or electron-donating group, where n ≥ 1. In some embodiments, n = 1, 2, 3, 4. It should be noted that when R1 in the first polymerizable monomer A in this embodiment is a migratory electron-withdrawing group, then R2 is an electron-donating group, and when R1 is an electron-donating group, then R2 is a migratory electron-withdrawing group.

[0099] In this invention, the second monomer B is an electron-deficient olefin compound with carbon-carbon double bonds, exhibiting electron-deficient characteristics that readily undergo addition reactions with nucleophilic free radicals. Furthermore, the nucleophilic monomer free radical formed by the first monomer A and the initiator readily undergoes an addition reaction with the second monomer B to form an electrophilic free radical, which in turn readily undergoes an addition reaction with either the first monomer A or the second monomer B, thereby achieving copolymerization between different monomers.

[0100] In some embodiments, the migratable electron-withdrawing groups in the first polymerizable monomer A include benzofuran, benzothiophene, thiophene, oxazole, -CN, -SO2Ph, -NO2, etc. The above-mentioned types of migratable electron-withdrawing groups, under the action of an initiator, can easily migrate to the carbon atom at the distal end of the first polymerizing monomer A, providing a reaction site for the introduction of the second polymerizing monomer B. Moreover, it is beneficial to form new nucleophilic free radicals at the reaction site, thereby initiating the polymerization reaction of olefin compounds with carbon-carbon double bonds and electron-deficient properties, such as the second polymerizing monomer B.

[0101] In some embodiments, the electron-donating group in the first polymeric monomer A includes a phenyl or alkyl group. The connection of the electron-donating group to the formed primary active radical makes the primary active radical nucleophilic. This nucleophilic radical cannot undergo an addition reaction with the electron-rich first polymeric monomer A, but readily undergoes a polymerization reaction with the electron-deficient second polymeric monomer B, which has a carbon-carbon double bond, thereby promoting copolymer formation. In this embodiment, firstly, the first polymeric monomer A and an initiator are added to the polymerization reaction system. After heating, perhaps for half an hour, the initiator reacts with the first polymeric monomer A, and a primary active radical is formed along with the migration of functional groups. Because this primary active radical is connected to the electron-donating group, the entire primary active radical is nucleophilic. Therefore, this primary active radical cannot undergo an addition reaction with the electron-rich first polymeric monomer A, but can only undergo an addition reaction with the electron-deficient second polymeric monomer B, and so on, cyclically forming a copolymer with a definite structure.

[0102] In some embodiments, the second polymeric monomer B has the following general structural formula:

[0103]

[0104] In this embodiment, R3 in the second monomer B is a migratable electron-withdrawing group. The second monomer B contains a carbon-carbon double bond, exhibiting electron-deficient characteristics. It readily undergoes polymerization with the newly formed nucleophilic free radicals in the mother liquor of step one. Furthermore, the migratable electron-withdrawing group R3 in the second monomer B can provide reaction sites for further polymerization with the first monomer A, offering electrophilic free radicals to initiate a new round of polymerization in the first monomer A, thereby achieving an ordered polymerization reaction between different monomers.

[0105] In some embodiments, the second monomer B comprises at least one of acrylonitrile, acrylate compounds, methacrylates, acrylic acid, or acrylamide compounds. The above-mentioned types of second monomer B are advantageous in initiating the polymerization reaction of the first monomer A, thereby achieving polymerization reactions between different monomers to obtain a series of structurally stable copolymers.

[0106] In some embodiments, the second polymeric monomer B comprises at least one of the following structural formulas:

[0107]

[0108] In some embodiments, the initiator includes at least one of organic peroxides and azo compounds. Initiators of these types can generate free radicals under light and / or heat conditions, reacting with the first polymerizable monomer A while simultaneously promoting the migration of electron-withdrawing groups in the first polymerizable monomer A to distal carbon atoms, providing reaction sites for subsequent reactions with the second polymerizable monomer B.

[0109] In some embodiments, the organic peroxide includes at least one of acyl peroxides, hydrogen peroxides, dialkyl peroxides, ester peroxides, ketone peroxides, and dicarbonate peroxides.

[0110] In some embodiments, the azo compounds include at least one of azobisisobutyronitrile, azobisisoheptanenitrile, azobisisovalerate, azobiscyclohexylformitrile, and dimethyl azobisisobutyrate.

[0111] In some embodiments, the acyl peroxide includes at least one of benzoyl peroxide and lauroyl peroxide.

[0112] In some embodiments, the hydrogen peroxide includes at least one of cumene hydrogen peroxide and tert-butyl hydrogen peroxide.

[0113] In some embodiments, the dialkyl peroxide includes at least one of di-tert-butyl peroxide and dicumyl peroxide.

[0114] In some embodiments, the ester peroxide includes at least one of tert-butyl peroxide and tert-butyl peroxyvalerate.

[0115] In some embodiments, ketone peroxides include at least one of methyl ethyl ketone peroxide and cyclohexanone peroxide.

[0116] In some embodiments, the dicarbonate peroxide includes at least one of diisopropyl peroxide and dicyclohexyl peroxide.

[0117] The above types of initiators can generate free radicals at relatively low temperatures, which can easily react with the first polymerizing monomer A to obtain nucleophilic free radicals. At the same time, they promote the migration of electron-withdrawing groups in the first polymerizing monomer A to the distal carbon atom, providing reaction sites for subsequent reactions with different polymerizing monomers, such as the second polymerizing monomer B.

[0118] It should be noted that the initiators of the present invention are not limited to the types listed above. The initiators of the present invention include all compounds that can generate free radicals under light and / or heat conditions. For example, when the initiator is a dithioester compound, the initiator can generate free radicals under light conditions, which can then react with the first polymerizable monomer A to obtain nucleophilic free radicals, while promoting the migration of electron-withdrawing groups in the first polymerizable monomer A to the distal carbon atom, providing reaction conditions for subsequent reactions with different polymerizable monomers, such as the second polymerizable monomer B.

[0119] In some embodiments, the organic solvent in step two includes at least one of ethanol, acetonitrile, acetone, dimethyl sulfoxide, N,N-dimethylformamide, ethyl acetate, N-methylpyrrolidone, toluene, dimethyl sulfoxide, and chlorobenzene.

[0120] In some embodiments of step one, the molar ratio of the first polymeric monomer A to the initiator is 100:(1-50). For example, it can be any ratio within the range of 100:(1-50), such as 100:1, 100:5, 100:10, 100:15, 100:20, 100:25, 100:30, 100:35, 100:40, 100:45, 100:50, etc. Under the above ratio range, the first polymeric monomer A is added in excess relative to the initiator, which can promote the ordered polymerization between the first polymeric monomer A and the second polymeric monomer B, thereby obtaining a series of polymers with stable and ordered structures.

[0121] In some embodiments, the molar ratio of the first polymeric monomer A and the second polymeric monomer B can be in the range of (3–10):3, for example, any ratio within the range of (3–10):3 such as 10:3, 9.5:3, 3:1, 8:3, 7:3, 2:1, 5:3, 4:3, 3.5:3, 3:2, 1:1, etc. Under the above molar ratio range, the first polymeric monomer A is added in an equivalent or excess amount relative to the second polymeric monomer B, which is beneficial to promoting the ordered polymerization between the first polymeric monomer A and the second polymeric monomer B, thereby obtaining a series of polymers with stable and ordered structures. In this embodiment, the prepared polymer includes a structure similar to ABB, where A in the ABB structure refers to polymeric monomer A and B refers to polymeric monomer B.

[0122] In some embodiments, random polymers can also be obtained by controlling the feed ratio of the reaction raw materials. For example, the molar ratio of the first polymeric monomer A and the second polymeric monomer B is in the range of 3:(3 to 10), which can be any ratio in the range of 3:(3 to 10), such as 3:3.5, 3:4, 3:5, 3:6, 3:7, 3:8, 3:9, 3:10, etc. The first polymeric monomer A is added in small amounts relative to the second polymeric monomer B, which is beneficial to promoting the random copolymerization between the first polymeric monomer A and the second polymeric monomer B.

[0123] This invention is based on a functional group migration strategy, and by controlling the polarity of monomers during polymerization and varying the feeding ratio and order of different monomers, it can not only obtain ordered copolymers with well-defined structures, but also prepare random copolymers.

[0124] In some embodiments of step one, the heating reaction temperature is 45℃ to 150℃. For example, the heating temperature can be 45℃, 55℃, 65℃, 85℃, 95℃, 105℃, 115℃, 120℃, 130℃, 140℃, 145℃, 150℃, etc., which are reaction temperatures of 45℃ to 150℃.

[0125] It should be noted that the temperature conditions listed above are only some embodiments of the present invention. The present invention does not limit the temperature of the heating reaction, and the temperature of the heating reaction can be adjusted according to the temperature at which the initiator generates free radicals.

[0126] In some embodiments of step one, the heating reaction time is any reaction time of 0.5 h or more. For example, the reaction time can be any value of 0.5 h, 1 h, 2 h, 3 h, 4 h, 5 h, 6 h, 7 h, 8 h, 9 h, 10 h, 11 h, 12 h, 20 h, 30 h, 40 h, 50 h, etc., whichever is longer than 0.5 h. After the initiator and the first polymerizing monomer A are mixed, the above-mentioned heating reaction time limit is beneficial to obtaining a polymer with a higher conversion rate.

[0127] In some embodiments of step two, the heating reaction temperature is 45℃ to 150℃. For example, the heating temperature can be 45℃, 55℃, 65℃, 85℃, 95℃, 105℃, 115℃, 120℃, 130℃, 140℃, 145℃, 150℃, etc. Under the above reaction temperature conditions, polymerization between the second polymeric monomer B and the first polymeric monomer A can be promoted.

[0128] In some embodiments of step two, the heating reaction time is any reaction time of 1 hour or more.

[0129] In steps one and two, the present invention does not impose restrictions on the reaction atmosphere of the polymerization reaction, and the polymerization conditions are mild and simple. In some embodiments, the polymerization reaction can be carried out under air conditions, and in other embodiments, the polymerization reaction can also be carried out under a protective gas atmosphere, including nitrogen or argon.

[0130] In some embodiments of step two, the reaction solution is added dropwise to at least one of ethanol, acetonitrile, acetone, dimethyl sulfoxide, N,N-dimethylformamide, ethyl acetate, N-methylpyrrolidone, toluene, dimethyl sulfoxide, and chlorobenzene to induce precipitation, and the resulting precipitate is the polymer.

[0131] This invention utilizes the principle of functional group migration of free radicals. Under heating or light conditions, an initiator can generate free radicals that polymerize with a first monomer A. This causes the electron-withdrawing groups in the first monomer A to migrate to distant carbon atoms, providing reaction sites for the subsequent reaction with the second monomer B. Furthermore, the electron-withdrawing groups in the first monomer A react with the initiator to generate nucleophilic free radicals, which promote the polymerization of the second monomer B, thus achieving an ordered polymerization reaction of multiple monomers. The entire reaction is easy to operate, with mild reaction conditions, requiring no catalysts or other auxiliary agents. The polymerization cost is low, the monomer conversion rate is high, and the resulting polymer has low impurity content, few branches, high purity, novel and stable structure, and a high molecular weight with a relatively narrow molecular weight distribution. In some embodiments, the series of polymers obtained through the ordered polymerization reaction of the second monomer B and the first monomer A possess stable and novel structures, exhibiting good heat resistance and chemical corrosion resistance. The technical solution of this invention has potential market application prospects.

[0132] It should be noted that the functional group migration radical polymerization method of the present invention does not require the addition of catalysts or other auxiliary agents. This can be understood as follows: the functional group migration radical polymerization method of the present invention can complete the ordered polymerization reaction of various monomers to obtain structurally stable polymers even without the assistance of catalysts or other auxiliary agents. However, this does not mean that the polymerization method of the present invention cannot add catalysts or other auxiliary agents.

[0133] For example, in some embodiments of step one, during the step of mixing the first polymerizable monomer A and the initiator, an organic solvent can also be used to dissolve and mix the first polymerizable monomer A and the initiator. The organic solvent can promote the dissolution of the first polymerizable monomer A and the initiator, making them more uniformly mixed and promoting the polymerization reaction.

[0134] In this embodiment, the present invention does not limit the reaction concentration of the first polymerizable monomer A in the organic solvent; a higher reaction concentration is more conducive to the polymerization reaction. In some embodiments, the amount of the first polymerizable monomer A added is (3-10) mmol / mL, based on the volume (mL) of the organic solvent. The above ratio of organic solvent to first polymerizable monomer A is only one example of the present invention and does not constitute a limitation on the technical solution of the present invention. In some embodiments, the organic solvent includes at least one of ethanol, acetonitrile, acetone, dimethyl sulfoxide, N,N-dimethylformamide, ethyl acetate, N-methylpyrrolidone, toluene, dimethyl sulfoxide, and chlorobenzene. The above organic solvents have good solubility for the first polymerizable monomer A and the initiator, making the polymerizable monomer and initiator more uniformly mixed and promoting the polymerization reaction.

[0135] The present invention also provides a polymer prepared by the above-mentioned method of functional group migration radical copolymerization.

[0136] This invention does not limit the molecular weight of the polymer obtained. In some embodiments, the molecular weight of the polymer of this invention is above 1000. For example, the molecular weight of the polymer is any one of the following: 1000, 2000, 3000, 4000, 5000, 6000, 7000, 8000, 9000, 10000, 20000, 30000, 40000, 50000, 55000, 60000, 70000, 75000, 78000, 79000, 80000, 81000, 83000, 85000, 87000, 88000, 89000, 90000, 95000, 100000, etc., all above 1000. This invention allows for the control of polymer molecular weight by adjusting the amounts of the first polymeric monomer A, the second polymeric monomer B, and the initiator, as well as the temperature and time of the heating reaction, and the feeding ratio of the first polymeric monomer A and the second polymeric monomer B. This allows for the acquisition of a series of polymers with different molecular weights to meet diverse production needs and applications. Furthermore, because the entire polymerization process is easy to operate and operates under mild conditions, the reaction conditions can be easily adjusted to obtain polymers with different molecular weights to meet production requirements.

[0137] In some embodiments, the polymer of the present invention has a distribution width (PDI) of 1.10-4.00, which is relatively narrow, resulting in more stable physical properties and better chemical stability. In some embodiments, the distribution width of the polymer can be any value within the range of 1.10-4.00, such as 1.10, 1.20, 1.40, 1.60, 1.80, 2.00, 2.20, 2.40, 2.60, 2.80, 3.00, 3.20, 3.40, 3.60, 3.80, or 4.00.

[0138] In some embodiments, the polymer obtained by the present invention has the following general structural formula:

[0139]

[0140] Where R1 is an electron-donating group, R2 is a migratable electron-withdrawing group, R3 is a migratable electron-withdrawing group, and n, x, and y are all greater than or equal to 1.

[0141] In some embodiments, the polymer has the following structural formula (Ⅰ):

[0142] Where x and y are both greater than or equal to 1.

[0143] The polymer in this embodiment has a high acrylonitrile content, which gives it good solvent resistance, chemical corrosion resistance, high decomposition temperature, high strength, and high hardness.

[0144] In one embodiment, the structural formula (Ⅰ) is as follows:

[0145]

[0146] In some embodiments, the polymer has the following structural formula (II):

[0147] Where x and y are both greater than or equal to 1.

[0148] The polymer in this embodiment has high resistance to solvents, chemical corrosion, and high temperatures.

[0149] In one embodiment, the structural formula (II) is as follows:

[0150]

[0151] In some embodiments, the polymer has the following structural formula (Ⅲ):

[0152] Where x and y are both greater than or equal to 1.

[0153] The polymer in this embodiment contains bromine atoms in its main chain, giving the material a pale yellow color. It also exhibits high resistance to solvents, chemical corrosion, and high temperatures.

[0154] In one embodiment, the structural formula (Ⅲ) is as follows:

[0155]

[0156] In some embodiments, the polymer has the following structural formula (Ⅳ):

[0157] Where x and y are both greater than or equal to 1.

[0158] The polymer in this embodiment has high resistance to solvents, chemical corrosion, and high temperatures.

[0159] In one embodiment, the structural formula (Ⅳ) is as follows:

[0160]

[0161] In some embodiments, the polymer has the following structural formula (V):

[0162] Where x and y are both greater than or equal to 1.

[0163] The polymer in this embodiment exhibits high solvent resistance, chemical corrosion resistance, and high-temperature resistance. In one embodiment, the structural formula (V) is as follows:

[0164]

[0165] In some embodiments, the polymer has the following structural formula (VI):

[0166] Where x and y are both greater than or equal to 1.

[0167] The polymer in this embodiment exhibits high solvent resistance, chemical corrosion resistance, and high-temperature resistance. In one embodiment, the structural formula (VI) is as follows:

[0168]

[0169] In some embodiments, the polymer has the following structural formula (VII):

[0170] Where x and y are both greater than or equal to 1.

[0171] The polymer in this embodiment exhibits high solvent resistance, chemical corrosion resistance, and high-temperature resistance. In one embodiment, the structural formula (VII) is as follows:

[0172]

[0173] In some embodiments, the polymer has the following structural formula (VIII):

[0174] Where x and y are both greater than or equal to 1.

[0175] The polymer in this embodiment exhibits high solvent resistance, chemical corrosion resistance, and high-temperature resistance. In one embodiment, the structural formula (VIII) is as follows:

[0176]

[0177] In some embodiments, the polymer has the following structural formula (IX):

[0178] Where x and y are both greater than or equal to 1.

[0179] In one embodiment, the structural formula (IX) is as follows:

[0180]

[0181] Furthermore, it should be noted that the first polymeric monomer A and the second polymeric monomer B listed above are merely some embodiments of the technical solution of this invention. This invention does not limit the preparation methods of all types of first polymeric monomer A and second polymeric monomer B mentioned above; they can be prepared using methods well known to those skilled in the art, or the initiator and the second polymeric monomer B can be purchased.

[0182] This invention provides one method for preparing the first polymeric monomer A, but this method should not be considered as a limitation of the technical solution of this invention.

[0183] In some embodiments, the method for preparing the first polymeric monomer A includes the following steps:

[0184] Step 1: Weigh NaH or lithium diisopropylamino (LDA) (1.2 equiv.) into a two-necked flask, seal and purge with nitrogen three times, add N,N-dimethylformamide at 0°C, and stir for 30 min to obtain the reaction solution.

[0185] Step two, slowly add to the reaction solution from step one (2.0 equiv.), continue stirring at 0°C for 0.5 h to 2 h, then add to the reaction system (1.0 equivalent). Among them, The R1 group is a migratable electron-withdrawing group, which can be -CN, -F, -Cl, -COOR3 (R3 is an aliphatic chain), -SO2Ph or -NO2; The X groups in it include -Cl and -Br.

[0186] Step 3: The reaction results are detected by thin-layer chromatography. After the reaction is completed, the reaction is quenched with saturated NH4Cl solution, and then the reaction product is extracted with ethyl acetate. The reaction product is then purified by vacuum distillation or column chromatography.

[0187] The technical solution of the present invention will be further described in detail below with reference to specific embodiments. It should be understood that the following specific embodiments are only used to explain the present invention and are not intended to limit the present invention.

[0188] The initiator and second monomer B used in Examples 1 to 18 below were all purchased, and the structure of the second monomer B is as follows: Examples 1 to 9

[0189] The polymerization methods for functional group migrating radicals in Examples 1 to 9 include the following steps:

[0190] Step 1: Place 3.5 mmol of the first monomer A in a pressure-resistant tube according to the reaction conditions in Table 1, then add the initiator, purge the nitrogen gas three times, add 1 mL of the reaction solvent ethanol, and then heat the reaction under a nitrogen atmosphere at 100℃~150℃ for 30 min according to the reaction conditions in Table 1 to obtain the reaction mother liquor.

[0191] Step 2: Slowly add the second monomer B to the reaction mother liquor from Step 1, and then carry out the reaction at 45℃~100℃ according to the reaction conditions in Table 1 to obtain the reaction solution. The reaction solution is then added dropwise to a hexane or methanol solution to precipitate and obtain the polymer.

[0192] Table 1 Reactant conditions and polymerization conditions of the examples

[0193]

[0194] Example 10

[0195] Example 10 follows the preparation method of Example 1, except that N,N-dimethylformamide solution is used as the reaction solvent to dissolve the polymerization monomer and initiator, and the amount of N,N-dimethylformamide solution added is 1 mL.

[0196] Examples 11 to 18

[0197] Examples 11 to 18 are prepared using the same method as Example 1, except that the first polymeric monomer A used in Examples 11 to 18 has a different structure, resulting in different polymer structures.

[0198] The structural formulas of the polymer monomers used in Examples 1 to 18 and the structural formulas of the resulting polymers are shown in Table 2.

[0199] Table 2. Monomer Structures and Polymer Structures

[0200]

[0201] Structural performance testing

[0202] 1. The polymer obtained in Example 1 was characterized using a proton nuclear magnetic resonance (NMR) spectrometer. The characterization results are shown in the figure below. Figure 1 ,like Figure 1 As shown, the structure of the copolymer synthesized by the method of this invention can be determined by analysis of 1H NMR spectroscopy.(j) The position of hydrogen is the chemical shift value of the hydrogen on the benzene ring, while H (b,g,i) The positions of the hydrogen atoms connected to the cyano group are shown in the figure. The ratio of the two monomers can be deduced from the ratio of the number of hydrogen atoms at these two locations. In this figure, the ratio is approximately 5:3, so the resulting polymer structure is in the form of ABB.

[0203] 2. Determine the yield, molecular weight, distribution width, and T of the polymers prepared in Examples 1 to 18. g (°C), T d，5％ (°C), the test results are shown in Table 3.

[0204] Table 3 Properties of the polymers obtained in Examples 1 to 18

[0205]

[0206] As shown in Tables 2 and 3, the present invention utilizes the method of functional group migration free radicals to select the first and second polymers, adjust the polarity of the polymers during the polymerization process, and enable two different monomers to undergo ordered polymerization reactions to obtain a series of polymers. The polymers are diverse in type, rich in structure, novel and stable, and have various properties. Moreover, the monomer conversion rate is high, and the obtained polymers have a wide range of molecular weights and a narrow distribution width, which can meet different production needs and has potential application value.

[0207] The above are merely preferred embodiments of the present invention and do not limit the patent scope of the present invention. Any equivalent structural or procedural transformations made based on the content of the present invention's specification and drawings, or direct or indirect applications in other related technical fields, are similarly included within the patent protection scope of the present invention.

Claims

1. A method for functional group migration radical copolymerization, characterized in that, The following steps are involved: Step 1: Mix the initiator and the first monomer A, and heat the mixture to obtain the reaction mother liquor; Step 2: Add the second monomer B dropwise to the mother liquor of the reaction, heat the reaction to obtain a reaction solution, and precipitate the reaction solution in an organic solvent to obtain a polymer; in, The initiator includes compounds that can generate free radicals under light and / or heat conditions; The first polymerizable monomer A comprises an olefin compound containing four or more carbon atoms, and includes electron-donating groups and electron-withdrawing groups that can migrate. The second polymerizable monomer B includes an electron-deficient olefin compound.

2. The method for functional group migration radical copolymerization according to claim 1, characterized in that, The electron-withdrawing groups that can migrate in the first polymerizable monomer A include benzofuran, benzothiophene, thiophene, oxazole, -CN, -SO2Ph, and -NO2. And / or, the electron-donating group in the first polymeric monomer A includes phenyl or alkyl groups; And / or, the second polymerizable monomer B includes at least one of acrylonitrile, acrylate compounds, methacrylates, acrylic acid, or acrylamide compounds; And / or, the initiator includes at least one of organic peroxides and azo compounds; And / or, the organic solvent includes at least one of ethanol, acetonitrile, acetone, dimethyl sulfoxide, N,N-dimethylformamide, ethyl acetate, N-methylpyrrolidone, toluene, dimethyl sulfoxide, and chlorobenzene; And / or, the first polymeric monomer A has the following general structural formula: in, n≥1 in the first polymerizable monomer A; R1 in the first polymeric monomer A includes a migratable electron-withdrawing group or an electron-donating group; R2 in the first polymeric monomer A includes a migratable electron-withdrawing group or an electron-donating group; And / or, The second polymerizable monomer B has the following general structural formula: in, R3 in the second polymer monomer B includes an electron-withdrawing group.

3. The method for functional group migration radical copolymerization according to claim 2, characterized in that, The initiator includes at least one of organic peroxides and azo compounds. in, The organic peroxides include at least one of acyl peroxides, hydrogen peroxides, dialkyl peroxides, ester peroxides, ketone peroxides, and dicarbonate peroxides; And / or, the azo compounds include at least one of azobisisobutyronitrile, azobisisoheptanenitrile, azobisisovalerate, azobiscyclohexylformitrile, and dimethyl azobisisobutyrate.

4. The method for functional group migration radical copolymerization according to claim 3, characterized in that, The organic peroxide is an acyl peroxide, which includes at least one of benzoyl peroxide and lauroyl peroxide; And / or, the organic peroxide is a hydrogen peroxide, and the hydrogen peroxide includes at least one of cumene hydrogen peroxide and tert-butyl hydrogen peroxide; And / or, the organic peroxide is a dialkyl peroxide, which includes at least one of di-tert-butyl peroxide and dicumyl peroxide; And / or, the organic peroxide is an ester peroxide, which includes at least one of tert-butyl peroxide and tert-butyl peroxide; And / or, the organic peroxide is a ketone peroxide, which includes at least one of methyl ethyl ketone peroxide and cyclohexanone peroxide; And / or, the organic peroxide is a dicarbonate peroxide, which includes at least one of diisopropyl peroxide and dicyclohexyl peroxide.

5. The method for functional group migration radical copolymerization according to claim 1, characterized in that, The molar ratio of the first polymerizable monomer A to the initiator is in the range of 100:(1~50); And / or, the molar ratio of the first polymeric monomer A and the second polymeric monomer B is in the range of (3 to 10):3; or, the molar ratio of the first polymeric monomer A and the second polymeric monomer B is in the range of 3:(3 to 10).

6. The method for functional group migrating radical copolymerization according to claim 1, characterized in that, In step one, the temperature range of the heating reaction is 45℃~150℃; And / or, in step one, the heating reaction time is greater than or equal to 0.5 h; And / or, in step two, the temperature range of the heating reaction is 45°C to 150°C; And / or, in step two, the heating reaction time is greater than or equal to 1 hour; And / or, the heating reaction in step one and the heating reaction in step two are carried out in a protective atmosphere or air, the protective atmosphere including nitrogen or argon; And / or, in step one, the first polymerizable monomer A and the initiator are dissolved and mixed in an organic solvent; And / or, in step one, the first polymeric monomer A and the initiator are dissolved and mixed in an organic solvent, and the amount of the first polymeric monomer A added is (3-10) mmol / mL, based on the volume of the organic solvent in mL. And / or, in step one, the first polymerization monomer A and the initiator are dissolved and mixed in an organic solvent, the organic solvent including at least one of ethanol, acetonitrile, acetone, dimethyl sulfoxide, N,N-dimethylformamide, ethyl acetate, N-methylpyrrolidone, toluene, dimethyl sulfoxide, and chlorobenzene.

7. A polymer prepared by the method of functional group migration radical copolymerization according to any one of claims 1 to 6.

8. The polymer according to claim 7, characterized in that, The polymer has a molecular weight of 1000 or higher; And / or, the distribution width (PDI) of the polymer is 1.10-4.00; And / or, the conversion rate of the first polymeric monomer A is 10%-90%; And / or, the conversion rate of the second polymerizable monomer B is 10%-90%; And / or, the polymer has the following general structural formula: R1 includes an electron-donating group, R2 includes a migratable electron-withdrawing group, R3 includes a migratable electron-withdrawing group, and n, x, and y are all greater than or equal to 1.

9. The polymer according to claim 8, characterized in that, The polymer has the following general structural formula: in, The polymer has the following structural formula (Ⅰ): Where x and y are both greater than or equal to 1; or, It has the following structural formula (II): Where x and y are both greater than or equal to 1; or, It has the following structural formula (Ⅲ): Where x and y are both greater than or equal to 1; or, It has the following structural formula (Ⅳ): Where x and y are both greater than or equal to 1; or, It has the following structural formula (V): Where x and y are both greater than or equal to 1; or, It has the following structural formula (VI): Where x and y are both greater than or equal to 1; or, It has the following structural formula (Ⅶ): Where x and y are both greater than or equal to 1; or It has the following structural formula (VIII): Where x and y are both greater than or equal to 1; or, It has the following structural formula (IX): Where x and y are both greater than or equal to 1.

10. The polymer according to claim 9, characterized in that, The structural formula (Ⅰ) is as follows: n is greater than or equal to 1; And / or, the structural formula (II) is as follows: n is greater than or equal to 1; and / or, the structure (Ⅲ) is as follows: n is greater than or equal to 1; And / or, the structural formula (Ⅳ) is as follows: n is greater than or equal to 1; And / or, the structural formula (V) is as follows: n is greater than or equal to 1; And / or, the structural formula (VI) is as follows: n is greater than or equal to 1; And / or, the structural formula (VII) is as follows: n is greater than or equal to 1; And / or, the structural formula (VIII) is as follows: n is greater than or equal to 1; And / or, the structural formula (IX) is as follows: n is greater than or equal to 1.

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