A cyclopolymerization method based on free radical migration and polymer thereof

Abstract

This invention discloses a cyclization polymerization method based on free radical migration and its polymer, belonging to the field of cyclization polymer polymerization technology. The invention involves mixing a monomer and an initiator, followed by heating to react and obtain the polymer. The monomer is a diene compound, including electron-withdrawing groups and migratable functional groups; the initiator includes compounds that can generate free radicals under light and / or heat conditions. This invention utilizes a free radical migration strategy, requiring only heating and / or light conditions for the initiator to generate free radicals to initiate the cyclization polymerization of the monomer to form a cyclized polymer. The entire reaction process is easy to operate, the reaction conditions are mild, no auxiliary agents such as catalysts are needed, the polymerization cost is low, the conversion rate is high, and the obtained polymer has a high degree of cyclization, a high molecular weight, a relatively narrow molecular weight distribution, and a stable structure.

Description

Technical Field

[0001] This invention relates to the field of cyclization polymer technology, and more particularly to a cyclization polymerization method based on free radical migration and its polymer. Background Technology

[0002] Hydrocarbon polymers with five- or six-membered rings in repeating units hold promise for high optical transparency, thermal stability, and mechanical strength. For example, the cyclic polymer COP, developed and produced by Zeon Corporation of Japan, is used in medical optical components and high-end pharmaceutical packaging materials. Common reactions for obtaining cyclic polymers include ring-opening metathesis polymerization of bicyclic olefins (such as norbornene) and addition polymerization of cyclic olefins (including cyclopentene and norbornene) catalyzed by transition metal complexes; copolymerization of acyclic and cyclic olefins yields polymers with randomly occurring rings along the polymer chain; cyclopolymerization of non-conjugated dienes allows polymer growth and the formation of five- to eight-membered rings along the polymer chain, providing polymers with these cyclic units; cyclopolymerization of dienes and copolymerization of olefins with dienes yield polymers with cyclic groups along the polymer chain, primarily using early transition metal complexes as catalysts. The polymerization reaction that forms linear polymers with repeating cyclic units from non-conjugated dienes is called cyclization polymerization. Its products exhibit high heat resistance; therefore, cyclization polymerization is a method for preparing heat-resistant polymers.

[0003] Cyclopolymerization of dienes can be broadly classified into two categories: metal-catalyzed cyclization and radical-mediated cyclization. Metal-catalyzed cyclization has developed numerous catalytic systems, such as the Ziegler-Natta system, metallocene systems (including dicelocenes and monocelocenes), non-celocene transition metal systems, and rare earth systems. However, due to the high reactivity of metal catalysts (Pd, Ni, etc.) with olefins, the type of ring in the repeating unit of the polymerization product is often not unique, and the reaction conditions are harsh, the catalysts are expensive, and recovery and purification are difficult. Radical-mediated diene cyclization has advantages over metal-catalyzed polymerization, such as lower cost and no metal doping. The disadvantage is that the monomer structure is unique, often requiring the introduction of electron-withdrawing groups next to the olefin to increase the intermolecular olefin's ability to capture free radicals. This increases the number of monomer synthesis steps, reduces the universality of the reaction, and increases the reaction cost. The generated electron-deficient free radicals may also directly add to the next olefin molecule without cyclization, resulting in a decrease in the proportion of rings in the polymer and the retention of side chains. To address this issue, this invention patent fundamentally solves the problem of cyclization polymerization of non-conjugated dienes and develops a novel synthesis method. Summary of the Invention

[0004] The main objective of this invention is to provide a cyclization polymerization method based on free radical migration and its polymer, which is simple to operate, has mild process conditions, high conversion rate, and low cost.

[0005] To achieve the above objectives, the present invention provides a cyclization polymerization method based on free migration, comprising the following steps: mixing a monomer and an initiator, and heating to react and obtain a polymer;

[0006] in,

[0007] The monomer is a diene compound, which includes electron-withdrawing groups and migratable functional groups, and the initiator includes compounds that can generate free radicals under light and / or heat conditions.

[0008] In some embodiments of this application, the polymeric monomer comprises the following general structural formula:

[0009] R1 includes electron-withdrawing groups or migratable functional groups.

[0010] And / or, R2 includes electron-withdrawing groups or migratable functional groups.

[0011] In some embodiments of this application, the electron-withdrawing groups include -CN, -F, -Cl, -COOR3, -SO2Ph, -NO2, Wherein, R3 in -COOR3 includes aliphatic chains;

[0012] And / or, the migratable functional groups in the polymeric monomer include unsaturated functional groups or heteroatoms, wherein the unsaturated functional groups include cyano, aryl, heteroaryl, oxime, alkenyl, alkynyl or carbonyl, and the heteroatoms include halogen atoms, silicon or boron.

[0013] In some embodiments of this application, the initiator includes at least one of organic peroxides and azo compounds.

[0014] In some embodiments of this application, the organic peroxide includes at least one of acyl peroxides, hydrogen peroxides, dialkyl peroxides, ester peroxides, ketone peroxides, and dicarbonate peroxides;

[0015] And / or, the azo compounds include at least one of azobisisobutyronitrile, azobisisoheptanenitrile, azobisisovalerate, azobiscyclohexylformitrile, and dimethyl azobisisobutyrate.

[0016] In some embodiments of this application, the acyl peroxide includes at least one of benzoyl peroxide and lauroyl peroxide;

[0017] And / or, the hydroperoxide includes at least one of cumene hydroperoxide and tert-butyl hydroperoxide;

[0018] And / or, the dialkyl peroxide includes at least one of di-tert-butyl peroxide and dicumyl peroxide;

[0019] And / or, the ester peroxides include at least one of tert-butyl peroxide and tert-butyl peroxyvalerate;

[0020] And / or, the ketone peroxides include at least one of methyl ethyl ketone peroxide and cyclohexanone peroxide;

[0021] And / or, the dicarbonate peroxide includes at least one of diisopropyl peroxide and dicyclohexyl peroxide.

[0022] In some embodiments of this application, the molar ratio of the polymeric monomer to the initiator is 100:(0.5-20);

[0023] And / or, the temperature range of the heating reaction is above 60°C;

[0024] And / or, the heating reaction is carried out in a protective atmosphere or air, the protective atmosphere including nitrogen or argon;

[0025] And / or, in the step of mixing the polymerizing monomer and the initiator, the polymerizing monomer and the initiator may also be 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, diethylene glycol, and ethylene glycol.

[0026] To achieve the above objectives, this application also provides a polymer prepared by the cyclization polymerization method based on free radical migration as described above.

[0027] In some embodiments of this application, the polymer has a molecular weight of 1000 or higher;

[0028] And / or, the distribution width (PDI) of the polymer is 1.10-5.00;

[0029] And / or, the conversion rate of the polymeric monomer is 20%-95%;

[0030] And / or, the polymer has the following general structural formula:

[0031]

[0032] R1 in the general structural formula includes an electron-withdrawing group;

[0033] R2 in the general structural formula includes a migratable group;

[0034] In the general formula of the structure, n is a natural number greater than or equal to 1.

[0035] In some embodiments of this application, the polymer has the following structural formula (Ⅰ):

[0036]

[0037] In structural formula (Ⅰ), n is a natural number greater than or equal to 1; or, the polymer has structural formula (Ⅱ):

[0038]

[0039] In structural formula (II), n is a natural number greater than or equal to 1; or, the polymer has structural formula (III):

[0040]

[0041] In structural formula (III), n is a natural number greater than or equal to 1; or, the polymer has structural formula (IV):

[0042]

[0043] In the structural formula (Ⅳ), n is a natural number greater than or equal to 1; or, the polymer has the structural formula (Ⅴ):

[0044]

[0045] In the structural formula (V), n is a natural number greater than or equal to 1; or,

[0046] The polymer has the structural formula (VI):

[0047]

[0048] In the structural formula (VI), n is a natural number greater than or equal to 1; or,

[0049] The polymer has the structural formula (VII).

[0050]

[0051] In the structural formula (VII), n is a natural number greater than or equal to 1; or,

[0052] The polymer has the structural formula (VIII).

[0053]

[0054] In the structure (VIII), n is a natural number greater than or equal to 1.

[0055] The beneficial effects that this invention can achieve are:

[0056] This invention applies a free migration strategy to the synthesis of cyclic polymers. Only heating or light conditions are required for the initiator to generate free radicals to initiate the cyclization polymerization of non-conjugated dienes to form cyclic polymers. The entire reaction process is easy to operate, the reaction conditions are mild, no catalysts or other auxiliary agents are needed, the polymerization cost is low, and the conversion rate of the monomers is high. The resulting polymers have a high degree of cyclization, low impurity content, high purity, and stable structure.

[0057] The polymers synthesized by the free radical migration-based cyclization polymerization method of this invention can have a molecular weight of up to 60,000, a narrow molecular weight distribution, certain hardness and temperature resistance, and excellent optical properties.

[0058] This invention can obtain polymers containing different side groups by designing the migratable functional groups and electron-withdrawing groups of the polymer monomers, so that the polymers exhibit different states and properties to adapt to different application fields and application requirements. It has potential application value and is expected to be used as a glass-transparent and extremely pure plastic in fields such as medical, optical, packaging and electronic applications. Attached Figure Description

[0059] 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.

[0060] Figure 1 The image shows the proton NMR spectrum of the polymer obtained in Example 1 of this invention.

[0061] Figure 2 This is a physical image of the polymer obtained in Example 1 of the present invention.

[0062] 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 Implementation

[0063] It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

[0064] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0065] 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.

[0066] This invention provides a cyclization polymerization method based on free radical migration, comprising the following steps:

[0067] The polymer is obtained by mixing the monomer and the initiator and heating the mixture.

[0068] in,

[0069] The monomers are dienes, which include electron-withdrawing groups and migratable functional groups. The initiators include compounds that can generate free radicals under light and / or heat conditions.

[0070] This invention applies a free migration strategy to the synthesis of cyclic polymers. Only heating or light conditions are required for the initiator to generate free radicals, initiating the cyclization polymerization of non-conjugated dienes to form cyclic polymers. The resulting polymers are cyclic polymers. The entire reaction process is easy to operate, the reaction conditions are mild, no catalysts or other auxiliary agents are needed, the polymerization cost is low, and the monomer conversion rate is high, the degree of cyclization is high, and the obtained polymers have high cyclic content, high purity, and stable structure.

[0071] The reaction mechanism of the cyclization polymerization method based on free radical migration of the present invention is as follows: Under heating and / or light conditions, the initiator generates free radicals, which undergo an addition reaction with the non-conjugated diene compound of the polymer monomer to form alkyl free radicals. Then, the free radicals react with the migratable functional groups in the polymer monomers, causing the functional groups to migrate to the distal carbon atom and obtain another new free radical. This free radical continues to repeat the above reaction process with another molecule of polymer monomer. The polymerization reaction is carried out using the free migration strategy, and finally a polymer is obtained, which is a cyclized polymer.

[0072] This invention provides an embodiment to explain the reaction mechanism of the above-mentioned cyclization polymerization method based on free radical migration. 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.

[0073] In this embodiment, the monomer is monomer a, the migratable group in monomer a is -CN, the electron-withdrawing group is R1, and R is used as the initiator. The cyclization polymerization process based on free radical migration is as follows:

[0074]

[0075] First, under the action of initiator R, monomer a reacts to form an active secondary alkyl radical b. Radical b then undergoes tandem cyclization with another olefin unit within the molecule, generating radical c. Due to the presence of unsaturated bonds in the migratable functional group -CN, a bridged cyclic imine radical d is formed, which subsequently initiates the breaking of the C-C bond and cyano group migration, ultimately forming an alkyl radical e. Radical e reacts with another monomer molecule to form a monomer radical, which repeats the above reaction process, eventually forming a polymer, which is a cyclized polymer.

[0076] In some embodiments, the polymeric monomer comprises the following general structural formula: R1 includes an electron-withdrawing group or a migratable functional group, and / or R2 includes an electron-withdrawing group or a migratable functional group. It should be noted that when R1 is an electron-withdrawing group, R2 is a migratable functional group, and vice versa, so that the polymer monomer contains both a migratable functional group and an electron-withdrawing group.

[0077] In some embodiments, the electron-withdrawing groups in the polymeric monomer include -CN, -F, -Cl, -COOR3, -SO2Ph, -NO2, etc. And so on. Among them, R3 in -COOR3 includes aliphatic chains. Under the action of an initiator, the electron-withdrawing groups of the above types can promote the migration of migratory functional groups, causing them to migrate to the distal carbon atom, providing polymerization reaction sites for the next monomer.

[0078] In some embodiments, the migratable functional groups in the polymerizable monomer include unsaturated functional groups or heteroatoms. Unsaturated functional groups include cyano, aryl, heteroaryl, oxime, alkenyl, alkynyl, or carbonyl groups, while heteroatoms include halogen atoms, silicon, or boron. These types of migratable functional groups can undergo migration reactions under the induction of free radicals, migrating to distant carbon atoms. The initiator can then continuously introduce new polymerizable monomers, ultimately completing the polymerization reaction to obtain the polymer.

[0079] This invention does not limit the type of initiator. In some embodiments, the initiator includes at least one of organic peroxides and azo compounds. Initiators of the above types can generate free radicals under light and / or heat conditions, reacting with the polymerizing monomer to obtain alkyl free radicals and generating a new free radical center. This promotes the migration of migratory functional groups in the polymerizing monomer, continuously introducing new polymerizing monomers using a free radical rearrangement strategy, ultimately obtaining the polymer.

[0080] In some embodiments, the organic peroxide includes at least one of acyl peroxides, hydrogen peroxides, dialkyl peroxides, ester peroxides, ketone peroxides, and dicarbonate peroxides.

[0081] In some embodiments, the azo compounds include at least one of azobisisobutyronitrile, azobisisoheptanenitrile, azobisisovalerate, azobiscyclohexylformitrile, and dimethyl azobisisobutyrate.

[0082] In some embodiments, the acyl peroxide includes at least one of benzoyl peroxide and lauroyl peroxide.

[0083] In some embodiments, the hydrogen peroxide includes at least one of cumene hydrogen peroxide and tert-butyl hydrogen peroxide.

[0084] In some embodiments, the dialkyl peroxide includes at least one of di-tert-butyl peroxide and dicumyl peroxide.

[0085] In some embodiments, the ester peroxide includes at least one of tert-butyl peroxide and tert-butyl peroxyvalerate.

[0086] In some embodiments, ketone peroxides include at least one of methyl ethyl ketone peroxide and cyclohexanone peroxide.

[0087] In some embodiments, the dicarbonate peroxide includes at least one of diisopropyl peroxide and dicyclohexyl peroxide.

[0088] The above types of initiators can generate free radicals at relatively low temperatures, which in turn promote the migration of migratory functional groups of polymeric monomers and continuously introduce new polymeric monomers, ultimately obtaining polymers.

[0089] 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, thereby promoting the rearrangement reaction of the migratable functional groups of the polymerizable monomers, continuously introducing new polymerizable monomers, and finally obtaining the polymer.

[0090] This invention does not limit the molar ratio of monomer to initiator in the polymerization reaction. In some embodiments, the molar ratio of monomer to initiator is 100:(0.5-20). For example, the molar ratio can be any ratio within the range of 100:(1-20), such as 100:0.5, 100:1, 100:2, 100:4, 100:5, 100:6, 100:7, 100:8, 100:9, 100:10, 100:11, 100:12, 100:13, 100:14, 100:15, 100:16, 100:17, 100:18, 100:19, 100:20, etc. However, it is not limited to the ratio ranges listed above.

[0091] In some embodiments, the heating reaction temperature is above 60°C. For example, the heating temperature can be 60°C, 70°C, 80°C, 90°C, 100°C, 110°C, 120°C, 130°C, 140°C, 150°C, 180°C, 200°C, 400°C, 500°C, 600°C, 700°C, 800°C, 900°C, 1000°C, or other reaction temperatures above 60°C. This invention can induce the initiator to generate free radicals under relatively mild conditions, initiating the polymerization of monomers to obtain a polymer.

[0092] 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.

[0093] In some embodiments, the heating reaction time is any reaction time of 1 hour or more. For example, the reaction time can be any value of 1 hour or more, such as 1 hour, 2 hours, 3 hours, 4 hours, 5 hours, 6 hours, 7 hours, 8 hours, 9 hours, 10 hours, 11 hours, 12 hours, 20 hours, 30 hours, 40 hours, or 50 hours. Under the above-mentioned heating reaction time constraints, it is advantageous to obtain polymers with higher conversion rates.

[0094] This invention does not impose restrictions on the reaction atmosphere of the cyclization polymerization reaction, and the conditions for the cyclization polymerization reaction are mild and simple. In some embodiments, the cyclization polymerization reaction can be carried out under air conditions, and in other embodiments, the cyclization polymerization reaction can also be carried out under a protective gas atmosphere, including nitrogen or argon.

[0095] This invention applies a free radical migration strategy to cyclization polymerization. Under heating or light conditions, the initiator can generate free radicals to initiate the polymerization of monomers, forming a cyclized polymer. The resulting polymer is a cyclized polymer. The entire reaction is easy to operate, the reaction conditions are mild, and no auxiliary agents such as catalysts are required. The cyclization polymerization cost is low, the monomer conversion rate is high, and the obtained polymer has low impurity content, high purity, high molecular weight, relatively narrow molecular weight distribution, and relatively stable structure, exhibiting certain hardness and temperature resistance. Furthermore, in some embodiments, the polymer prepared by this invention can also achieve a glassy appearance.

[0096] It should be noted that the free migration cyclization polymerization method of the present invention does not require the addition of catalysts or other auxiliary agents. It can be understood that the free migration cyclization polymerization method of the present invention can complete the cyclization polymerization reaction to obtain polymers even without the assistance of catalysts or other auxiliary agents. However, this does not mean that the cyclization polymerization method of the present invention cannot add catalysts or other auxiliary agents.

[0097] For example, in some embodiments, during the step of mixing the monomer and the initiator, an organic solvent can also be used to dissolve and mix the monomer and the initiator. The organic solvent can promote the dissolution of the monomer and the initiator, resulting in a more uniform mixture.

[0098] This invention does not limit the reaction concentration of the monomer in the organic solvent; a higher reaction concentration is more conducive to the polymerization reaction. In some embodiments, the amount of monomer added is (0.5-20) mmol / mL, based on the volume of the organic solvent (mL). The above ratios of organic solvent and monomer are merely some examples of this invention and do not constitute a limitation on the technical solution of this invention.

[0099] This invention does not limit the type of organic solvent. In some embodiments, the organic solvent includes at least one selected from ethanol, acetonitrile, acetone, dimethyl sulfoxide, N,N-dimethylformamide, ethyl acetate, diethylene glycol, and ethylene glycol. These organic solvents have good solubility for both the monomers and the initiator, promoting more uniform mixing of the monomers and initiator and facilitating the cyclization polymerization reaction.

[0100] The present invention also provides a polymer prepared by the cyclization polymerization method based on free radical migration as described above.

[0101] This invention does not limit the molecular weight of the polymers obtained. In some embodiments, the molecular weight of the polymers of this invention is above 1000, and can even reach 60,000. For example, the molecular weight of the polymer can be any one of the following: 1000, 2000, 3000, 4000, 5000, 6000, 7000, 8000, 9000, 10000, 20000, 30000, 40000, 50000, 60000, etc., all above 1000. This invention can control the molecular weight of the polymer by controlling the amount of monomers and initiators added, as well as the temperature and time of the heating reaction, to obtain polymers with a wide range of molecular weights to meet different production needs. Moreover, because the entire polymerization process is easy to operate and the conditions are mild, the reaction conditions can be easily adjusted to obtain polymers with different molecular weights to meet production requirements.

[0102] In some embodiments, the distribution width (PDI) of the polymer of the present invention is 1.10-5.00, which is relatively narrow and the physical properties of the polymer are relatively stable.

[0103] The conversion rate of the polymerizable monomer is related to factors such as reaction temperature, reaction time, and initiator dosage, and the conversion rate can be controlled by controlling the above conditions. In some embodiments, the conversion rate of the polymerizable monomer of the present invention is 20%-95%, for example, it can be any conversion rate in the range of 20%-95%, such as 20%, 30%, 40%, 50%, 60%, 70%, 80%, 90%, 95%, etc.

[0104] In some embodiments, the polymers of the present invention have the following general structural formula:

[0105]

[0106] In the general structural formula, R1 is an electron-withdrawing group and R2 is a migratable functional group; n is a natural number greater than or equal to 1, and R1 and R2 depend on the structure of the polymer monomer.

[0107] In some embodiments, the polymer has structural formula (Ⅰ):

[0108]

[0109] In structural formula (Ⅰ), n is a natural number greater than or equal to 1. The polymer in this embodiment is polymerized from monomers with both migratable functional groups and electron-withdrawing groups of -CN. The resulting polymer contains acrylonitrile structural units and a cyclic structure. The presence of the acrylonitrile structure gives the polymer oil resistance, abrasion resistance, and high mechanical strength, while the presence of the cyclic structure gives the polymer high hardness. It possesses an appearance and properties similar to plexiglass, and therefore has significant application prospects in the application of plexiglass.

[0110] In some embodiments, the polymer has structural formula (II):

[0111]

[0112] In structural formula (II), n is a natural number greater than or equal to 1. The polymer in this embodiment has acrylonitrile structural units and a cyclic structure. The presence of the acrylonitrile structure gives the polymer oil resistance, abrasion resistance, and high mechanical strength, while the presence of the cyclic structure gives the polymer high hardness.

[0113] In some embodiments, the polymer has structural formula (Ⅲ):

[0114]

[0115] In structural formula (Ⅲ), n is a natural number greater than or equal to 1. The polymer in this embodiment has acrylonitrile structural units and a cyclic structure. The presence of the acrylonitrile structure gives the polymer oil resistance, abrasion resistance, and high mechanical strength, while the presence of the cyclic structure gives the polymer high hardness.

[0116] In some embodiments, the polymer has structural formula (Ⅳ):

[0117]

[0118] In structural formula (Ⅳ), n is a natural number greater than or equal to 1. The polymer in this embodiment has acrylonitrile structural units and a cyclic structure. The presence of the acrylonitrile structure gives the polymer oil resistance, abrasion resistance, and high mechanical strength, while the presence of the cyclic structure gives the polymer high hardness.

[0119] In some embodiments, the polymer has the structural formula (V):

[0120]

[0121] In structural formula (V), n is a natural number greater than or equal to 1. The polymer in this embodiment has acrylonitrile structural units and a cyclic structure. The presence of the acrylonitrile structure gives the polymer oil resistance, abrasion resistance, and high mechanical strength, while the presence of the cyclic structure gives the polymer high hardness.

[0122] In some embodiments, the polymer has the structural formula (VI):

[0123]

[0124] In structural formula (VI), n is a natural number greater than or equal to 1. The polymer in this embodiment has acrylonitrile structural units and a cyclic structure. The presence of the acrylonitrile structure gives the polymer oil resistance, abrasion resistance, and high mechanical strength, while the presence of the cyclic structure gives the polymer high hardness.

[0125] In some embodiments, the polymer has the structural formula (VII):

[0126]

[0127] In structural formula (VII), n is a natural number greater than or equal to 1. The polymer in this embodiment has acrylonitrile structural units and a cyclic structure. The presence of the acrylonitrile structure gives the polymer oil resistance, abrasion resistance, and high mechanical strength, while the presence of the cyclic structure gives the polymer high hardness.

[0128] In some embodiments, the polymer has the structural formula (VIII):

[0129]

[0130] In structural formula (VIII), n is a natural number greater than or equal to 1. The polymer in this embodiment has acrylonitrile structural units and a cyclic structure. The presence of the acrylonitrile structure gives the polymer oil resistance, abrasion resistance, and high mechanical strength, while the presence of the cyclic structure gives the polymer high hardness.

[0131] It should be noted that the polymers listed above are only some embodiments of the technical solution of the present invention and do not constitute a limitation on the technical solution of the present invention.

[0132] It should be noted that the present invention does not limit the preparation methods of all types of polymer monomers mentioned above, and preparation methods well known to those skilled in the art can be selected.

[0133] Here, the present invention provides a method for preparing a polymer monomer, but this preparation method should not be regarded as a limitation on the technical solution of the present invention.

[0134] In some embodiments, the method for preparing the polymeric monomer includes the following steps:

[0135] Step 1: Weigh NaH (3.0 equiv.) into a two-necked flask, seal and purge with nitrogen three times, add tetrahydrofuran at 0°C, and stir for 30 min to obtain the reaction solution.

[0136] Step two, slowly add to the reaction solution from step one (1.0 equiv.), continue stirring at 0°C for 0.5 h to 2 h, then add to the reaction system (3.0 equivalent). Among them, The R1 group in the formula is an electron-withdrawing group, which can be -CN, -F, -Cl, -COOR3 (R3 is an aliphatic chain), -SO2Ph, or -NO2, etc. The X group in it includes -Cl, -Br, etc.

[0137] Step 3: The reaction results are detected by thin-layer chromatography. After the reaction is completed, the reaction is quenched with saturated NH4Cl solution, then the reaction product is extracted with ethyl acetate, and finally purified by column chromatography.

[0138] 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.

[0139] Preparation of polymer monomer a

[0140] The preparation method of polymeric monomer a in this embodiment includes the following steps:

[0141] Step 1: Weigh NaH (3.0 equiv.) into a two-necked flask, seal and purge with nitrogen three times, dissolve in tetrahydrofuran at 0°C, and stir for 30 min to obtain the reaction solution.

[0142] Step two, slowly add to the reaction solution from step one (1.0 equiv.), continue stirring at 0°C for 0.5 h to 2 h, then add to the reaction system (3.0 equivalent).

[0143] Step 3: The reaction results were detected by thin-layer chromatography to confirm that the reaction was complete. The reaction was then quenched with saturated NH4Cl solution, followed by extraction with ethyl acetate to obtain the reaction product. The reaction product was then purified by column chromatography.

[0144] The polymer monomer a prepared in this embodiment has the following structural formula: That is, the electron-withdrawing group and the migratable functional group in the polymer monomer a are -CN.

[0145] Examples 1 to 19

[0146] Examples 1 to 19, the cyclization polymerization method based on free radical migration, include the following steps:

[0147] According to Table 1, 5 mmol of monomer a was placed in a pressure-resistant tube, then an initiator was added, nitrogen gas was purged three times, and then the reaction was carried out under a nitrogen atmosphere according to the reaction conditions in Table 1 to obtain the polymer.

[0148] Table 1

[0149]

[0150] Examples 20 to 26

[0151] Examples 20 to 26 were prepared using the same method as Example 1, except that the polymer monomers used in Examples 20 to 26 had different structures, resulting in different polymer structures.

[0152] The structural formulas of the polymer monomers used in Examples 1 to 26 and the structural formulas of the resulting polymers are shown in Table 2.

[0153] Table 2. Monomer Structures and Polymer Structures

[0154]

[0155] Performance testing

[0156] 1. The monomer conversion rate (%) of polymer a in Examples 1 to 26, i.e. the yield of the obtained polymer, and the molecular weight and distribution width (PDI) of the obtained polymer were determined. The results are shown in Table 3.

[0157] 2. Taking the polymer prepared in Example 1 as an example, it was characterized by a hydrogen nuclear magnetic resonance spectrum, and the results were as follows: Figure 1 The hydrogen spectrum shown indicates that the structure of the polymer in this embodiment can be determined from this hydrogen spectrum.

[0158] 3. Taking the polymer prepared in Example 1 as an example, observe its appearance. The polymer in this example is amber in color, has a certain hardness, and has a glass-like appearance, which has application prospects in the field of plexiglass.

[0159] Table 3 Properties of the polymers obtained in Examples 1 to 26

[0160]

[0161] As shown in Tables 2 and 3, the polymers obtained by the free radical migration-based cyclization polymerization method of this invention are numerous, have rich structures, and diverse properties, which can meet different production needs and have potential application value. Moreover, the monomer conversion rate is high, the obtained polymers have a wide range of molecular weights and a narrow distribution width, and the polymer structure is relatively stable.

[0162] The above are merely preferred embodiments of the present invention and do not limit the scope of the patent. Any equivalent structural or procedural transformations made based on the description and drawings of the present invention, or direct or indirect applications in other related technical fields, are similarly included within the scope of patent protection of the present invention.

Claims

1. A cyclization polymerization method based on free radical migration, characterized in that, Includes the following steps: The polymer is obtained by mixing the monomer and the initiator and heating the mixture. in, The polymerization monomer is a diene compound, which includes electron-withdrawing groups and migratable functional groups. The initiator includes compounds that can generate free radicals under light and / or heat conditions; The polymeric monomers include the following general structural formulas: , R1 includes electron-withdrawing groups or migratable functional groups. And / or, R2 includes an electron-withdrawing group or a migratable functional group; The electron-withdrawing groups include -CN, -F, -Cl, -COOR3, -SO2Ph, and -NO2. , or Wherein, R3 in -COOR3 includes aliphatic chains; The migratable functional groups in the polymer monomer include unsaturated functional groups or heteroatoms, wherein the unsaturated functional groups include cyano, aryl, heteroaryl, oxime, alkenyl, alkynyl or carbonyl, and the heteroatoms include halogen atoms, silicon or boron.

2. The cyclization polymerization method based on free radical migration according to claim 1, characterized in that, The initiator includes at least one of organic peroxides and azo compounds.

3. The cyclization polymerization method based on free radical migration according to claim 2, characterized in that, 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 cyclization polymerization method based on free radical migration according to claim 3, characterized in that, The acyl peroxides include at least one of benzoyl peroxide and lauroyl peroxide; And / or, the hydrogen peroxides include at least one of cumene hydrogen peroxide and tert-butyl hydrogen peroxide; And / or, the dialkyl peroxide includes at least one of di-tert-butyl peroxide and dicumyl peroxide; And / or, the ester peroxides include at least one of tert-butyl peroxide and tert-butyl peroxyvalerate; And / or, the ketone peroxides include at least one of methyl ethyl ketone peroxide and cyclohexanone peroxide; And / or, the dicarbonate peroxide includes at least one of diisopropyl peroxide and dicyclohexyl peroxide.

5. The cyclization polymerization method based on free radical migration according to claim 1, characterized in that, The molar ratio of the polymerizable monomer to the initiator is 100:(0.5-20); And / or, the temperature range of the heating reaction is above 60°C; And / or, the heating reaction is carried out in a protective atmosphere or air, the protective atmosphere including nitrogen or argon; And / or, in the step of mixing the polymerizing monomer and the initiator, the polymerizing monomer and the initiator are dissolved and mixed in an organic solvent, the organic solvent including at least one selected from ethanol, acetonitrile, acetone, dimethyl sulfoxide, N,N-dimethylformamide, ethyl acetate, diethylene glycol, and ethylene glycol.

6. A polymer prepared by the cyclization polymerization method based on free radical migration as described in any one of claims 1 to 5.

7. The polymer according to claim 6, characterized in that, The polymer has a molecular weight of 1000 or higher; And / or, the distribution width (PDI) of the polymer is 1.10-5.00; And / or, the conversion rate of the polymeric monomer is 20%-95%; And / or, the polymer has the following general structural formula: R1 in the general structural formula includes an electron-withdrawing functional group; R2 in the general structural formula includes a migratable group; In the general formula of the structure, n is a natural number greater than or equal to 1.

8. The polymer according to claim 7, characterized in that, The polymer has the following structural formula (Ⅰ): （Ⅰ）， In the structural formula (Ⅰ), n is a natural number greater than or equal to 1; or, The polymer has structural formula (II): （Ⅱ）， In the structure (II), n is a natural number greater than or equal to 1; or, The polymer has structural formula (Ⅲ): （Ⅲ）， In the aforementioned structural formula (Ⅲ), n is a natural number greater than or equal to 1; or, The polymer has structural formula (Ⅳ): （Ⅳ）， In the structure (Ⅳ), n is a natural number greater than or equal to 1; or, The polymer has the structural formula (V): （Ⅴ）， In the structural formula (V), n is a natural number greater than or equal to 1; or, The polymer has the structural formula (VI): （Ⅵ）， In the structural formula (VI), n is a natural number greater than or equal to 1; or, The polymer has the structural formula (VII). （Ⅶ）， In the structure (VII), n is a natural number greater than or equal to 1; or, The polymer has the structural formula (VIII). （Ⅷ）， In the structure (VIII), n is a natural number greater than or equal to 1.

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