A micro-crosslinking isobutenyl elastomer and a method for preparing the same

Abstract

The application discloses a kind of micro-crosslinking isobutenyl elastomer, including the following raw materials by weight fraction: unsaturated functional monomer 0.1-10 parts, isobutene and conjugated diene 100 parts, main initiator 1.3x10 ‑5 ~1.3x10 ‑4 Parts, co-initiator 2.4-3.5 parts, dispersant chloromethane 300-800 parts; isobutene 90-100 parts, conjugated diene 0-10 parts; unsaturated functional monomer has the structure shown in the following formula I: formula IThe application generates crosslinking structure in isobutenyl elastomer by adding unsaturated functional monomer shown in formula I to the polymerization system of isobutenyl elastomer, double bond in monomer participates in cationic polymerization reaction, improves tensile strength and tear strength of isobutenyl elastomer, amino and ester group are polar groups, which can improve the processing performance of isobutenyl elastomer.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of high polymer materials, in particular to a micro-crosslinking isobutenyl elastomer and a preparation method thereof. BACKGROUND

[0002] Due to the characteristics of the molecular structure, isobutylene is suitable for preparing polymers by using a cationic initiation system. Isobutylene can be self-polymerized or copolymerized. The products obtained by polymerizing isobutylene or isobutylene and conjugated dienes have a regular linear structure. The most common products are polyisobutylene and butyl rubber obtained by copolymerizing isobutylene and isoprene. However, the existing polyisobutylene or butyl rubber has the problems of weak raw rubber strength and serious cold flow during storage (cold flow refers to the flow deformation of rubber during storage and cannot be restored to the original shape).

[0003] In view of the above problems, Petrochemical Technology (1998, 5(1)1:23-26.) discloses the main influencing factors and rules of synthesizing a terpolymer butyl rubber in a CH2Cl2 solvent by using isobutylene, isoprene and divinylbenzene as monomers and using AlCl3 and H2O as an initiation system. Divinylbenzene is a crosslinking agent. Increasing the monomer concentration is beneficial to accelerating the polymerization reaction rate. Increasing the amount of divinylbenzene increases the probability of divinylbenzene entering the polymer chain, so the crosslinking degree increases. Since the proportion of divinylbenzene in the total monomer amount is very small and the reactivity ratio of divinylbenzene is much smaller than that of isobutylene, divinylbenzene enters very little in the early stage of the polymerization chain. With the increase of the relative concentration of divinylbenzene, the divinylbenzene entering the polymer chain increases with the increase of the amount of divinylbenzene, but the conversion rate does not change much. However, this method can only adjust the crosslinking degree by adjusting the amount of divinylbenzene. With the increase of the amount of divinylbenzene, the gel content increases sharply, which loses practical value.

[0004] The master's degree thesis of Beijing University of Chemical Technology in 2007 "Preparation of hydrogen-bond crosslinked butyl rubber" discloses that 4-amino uracil is reacted with brominated butyl rubber to introduce 4-amino uracil into the molecular chain of butyl rubber. A network of hydrogen bonds between intermolecular amide bonds is formed to form a hydrogen-bond crosslinked network structure with thermal reversibility. The modified butyl rubber can be repeatedly processed thermoplastically. However, the reaction is carried out in a two-phase system and needs to use a phase transfer catalyst. The conversion rate gradually increases with the extension of the reaction time, but the reaction cannot reach a high conversion rate. The post-processing and purification steps are relatively complex.

[0005] Synthetic Rubber Industry (2009, 32(4):302-305.) discloses the heat-reversible quaternary ammonium crosslinking reaction of brominated butyl rubber, using a polymer containing a tertiary amine side group as a crosslinking agent to replace the traditional vulcanizing agent. Crosslinking occurs between the halogen functional group polymer and the amine functional group polymer, forming a -C-N-C- covalent crosslinking bond. Upon heating and shearing force, the reverse quaternization reaction occurs to break the crosslinking, and the material can be re-crosslinked after cooling. This technology is of great significance for the development of brominated butyl rubber products that can be repeatedly processed and used. However, this technology is based on the reverse quaternization reaction of quaternary ammonium crosslinking bonds under the action of heat and shearing force to prepare crosslinked brominated butyl rubber with thermoplastic reprocessing properties. During the reverse quaternization reaction, a small amount of bromomethane is produced.

[0006] Synthetic Rubber Industry (2008, (03): 195-199.) discloses the preparation of heat-reversible crosslinked butyl rubber by replacing bromine atoms in brominated butyl rubber with 4-amino uracil. The structure and tensile properties of IIR containing 4-amino uracil groups were investigated. Under the conditions of 4-amino uracil dosage 0.010 mol, phase transfer catalyst tetrabutylammonium bromide / amino uracil (molar ratio) 1:1, potassium hydroxide aqueous solution / toluene solution (volume ratio) 50:80, reaction temperature 80℃, and reaction time 4h, the maximum bromine atom substitution rate of 4-amino uracil after reaction with brominated butyl rubber can reach 77%. The tensile strength of butyl rubber containing 4-amino uracil groups is 2 times higher than that of brominated butyl rubber. However, the byproduct bromide is not easy to handle when brominated butyl rubber is used to prepare crosslinked butyl rubber.

[0007] Science and Technology Innovation (2020(33), 29-30) discloses the synthesis of hydroxyl-terminated polyisobutylene diols using active cationic polymerization method, and then the synthesis of butyl polyurethane elastomer material through conventional polyurethane polymerization process. The tensile strength of butyl polyurethane material decreases with the increase of polyisobutylene content, and when the polyisobutylene content is 60wt%, it has the best comprehensive mechanical properties. The butyl polyurethane material synthesized by this method has a dense side methyl structure, which makes its internal friction large and energy loss high, showing excellent damping performance. With the increase of PIB content, the maximum value of the corresponding loss factor also increases. However, this material has obvious block structure, and there is obvious performance difference between soft segment and hard segment.

[0008] The effect of six multifunctional monomers on the vulcanization of chlorinated butyl rubber was investigated in High Polymer Material Science and Engineering (1998, (06): 29-31). It was found that trimethylolpropane trimethacrylate could effectively increase the gel content and crosslinking density of chlorinated butyl rubber. The amount of trimethylolpropane trimethacrylate added and the tensile strength of chlorinated butyl rubber were positively correlated. However, if the local crosslinking is uneven, it is easy to cause molecular chain rupture, resulting in a decrease in product strength.

[0009] Chinese patent document CN101955592A provides a method for preparing thermoplastic reworkable crosslinked halogenated butyl rubber: a pyridine side group-containing polymer or dicyclopentadiene formate salt thermoreversible crosslinking agent is blended with halogenated butyl rubber, and a quaternization or esterification reaction occurs under hot pressing conditions to crosslink the rubber and obtain the product. The product undergoes reverse quaternization or reverse Diels-Alder reaction of the dicyclopentadiene crosslinking bridge under high-temperature hot pressing conditions, causing the crosslinked rubber to de-crosslink and exhibit thermoplastic processability. This scheme facilitates the reprocessing and utilization of rubber scraps and waste products. Although the invention provides a method for preparing crosslinked halogenated butyl rubber, its application range is relatively narrow, and it is only used for the reprocessing and utilization of rubber scraps and waste products.

[0010] Chinese patent document CN115850877A discloses a high-performance hydroxylated butyl rubber, a preparation method and application thereof. The hydroxylated butyl rubber is uniformly mixed with a reinforcing agent, a vulcanizing agent and a vulcanizing activator, and then vulcanized under high temperature and high pressure conditions to obtain a high-performance hydroxylated butyl rubber with excellent air tightness and fatigue resistance. This technology realizes high-speed crosslinking of the hydroxylated butyl rubber, and compared with ordinary butyl rubber and epoxidized butyl rubber, the vulcanized rubber has excellent air tightness and fatigue resistance, as well as good mechanical properties. However, the vulcanizing agent used in this technology is a substituted or unsubstituted aliphatic polyol acrylate, which is prone to produce volatile gases during the vulcanization process, increasing the production cost.

[0011] Chinese patent document CN114015170A discloses that epoxidized modified butyl rubber is uniformly mixed with a reinforcing agent, a vulcanizing agent and a vulcanizing activator, and then vulcanized under high temperature and high pressure to realize effective crosslinking of the epoxidized modified butyl rubber. Compared with ordinary butyl rubber and brominated butyl rubber, the vulcanized rubber has excellent air tightness and fatigue resistance, as well as good mechanical properties. The high-performance butyl rubber vulcanized rubber prepared by this method has good application prospects. Although polar groups can be introduced into the molecular chain during the epoxidation process, the epoxidation process is prone to cause molecular chain rupture, resulting in a decrease in the molecular weight of the product.

[0012] Chinese patent document CN110396163A discloses an aqueous crosslinking agent containing urethane structure, by controlling the monomer ratio of polyethylene glycol and the compound containing three isocyanate groups, a part of isocyanate groups is reserved after reaction, after adding the aqueous polyurethane, the remaining isocyanate groups play a crosslinking role. Moreover, the aqueous crosslinking agent containing urethane structure is a crosslinking agent for aqueous system application, does not participate in monomer reaction, and the isobutenyl elastomer polymerization is carried out in a water-free system, and the water content of the polymerized monomers is very harsh. SUMMARY

[0013] In view of the problems in the prior art and the direction for improvement, the present application provides a micro-crosslinked isobutenyl elastomer and a preparation method thereof. By adding a urethane functional monomer during the polymerization of isobutene or isobutene and conjugated diene, the double bonds at both ends of the monomer can participate in the polymerization of different active chains of polymers, forming a micro-crosslinked structure in the elastomer. This solves the problems of weak green strength and severe cold flow during storage of existing isobutenyl elastomers, thereby improving the tensile strength and tear strength of the isobutenyl elastomer. In addition, the urethane functional group is a polar group and is located between different isobutenyl elastomer molecular chains, which can increase the interaction between the isobutenyl elastomer molecular chains and the filler.

[0014] To achieve the above object, the present application provides the following technical scheme:

[0015] A micro-crosslinked isobutenyl elastomer, in terms of weight parts, comprises the following raw materials: 0.1-10 parts of unsaturated functional monomer, 100 parts of isobutene and conjugated diene, 1.3*10 -5 ~1.3*10 -4 parts of main initiator, 2.4-3.5 parts of co-initiator, and 300-800 parts of dispersant.

[0016] Among them, the isobutene is 90-100 parts, and the conjugated diene is 0-10 parts.

[0017] The unsaturated functional monomer has the following formula I structure:

[0018]

[0019] Formula I

[0020] n is an integer of 0-10, m is an integer of 0-5, z is an integer of 0-10, and n and z cannot be 0 at the same time.

[0021] R' and R" are independently selected from H, C6-C10 aryl, or C1-C5 straight chain or branched alkyl.

[0022] R is selected from unsubstituted or substituted phenylene, C1-C10 straight chain or branched alkylene, unsubstituted or substituted C6-C12 cycloalkylene,

[0023] R'" is selected from C1-C5 straight chain or branched alkyl.

[0024] In the above, "substituted" means that at least one H of the substituent group is replaced by C1-C5 alkyl, such as methyl, ethyl, isopropyl, n-propyl, butyl, t-butyl, isobutyl, n-pentyl, isopentyl, and the like.

[0025] Optionally, in the above micro-crosslinking isobutenyl-based elastomer provided by the present application, n is an integer from 0 to 5, m is an integer from 0 to 3, and z is an integer from 0 to 5.

[0026] R' and R" are each independently selected from H, phenyl, or methyl;

[0027] R'" is selected from methyl, ethyl, or butyl;

[0028] R is selected from

[0029] Optionally, in the above micro-crosslinking isobutenyl-based elastomer provided by the present application, the conjugated diene is selected from C4-C8 straight chain or branched diene, preferably C4-C6 diene, more preferably any one of isoprene, 2,3-dimethyl-1,3-butadiene, and 1,4-pentadiene.

[0030] The curved line in the above R group represents the connection position.

[0031] Optionally, in the above micro-crosslinking isobutenyl-based elastomer provided by the present application, the main initiator is selected from at least one of water, inorganic acid, and tertiary halogenated alkane; preferably, the tertiary halogenated alkane is selected from 2-chloro-2,4,4-trimethylpentane and the like, and the inorganic acid is selected from any one of HCl, HBr, HF, HClO4, HClSO3, H2SO4, H3PO4, and the like; more preferably, the main initiator is selected from water and / or HCl. In order to uniformly disperse the main initiator, if necessary, a dispersant can be added, and the dispersant can be selected from solvents such as dichloromethane.

[0032] Optionally, in the above micro-crosslinking isobutenyl-based elastomer provided by the present application, the co-initiator is selected from halogenated metal salt or organic aluminum compound.

[0033] Preferably, the halogenated metal salt is selected from at least one of BeCl2, ZnCl2, CdCl2, HgCl2, BF3, BCl3, AlCl3, AlBr3, SnCl4, TiCl4, TiBr4, ZrCl4, VCl4, WCl5, and FeCl3.

[0034] The general formula of the organic aluminum compound is R'"Al q X p-3 , wherein R'" is a C1-C8 linear or branched alkyl group, such as methyl, ethyl, isopropyl, n-propyl, t-butyl, n-pentyl, n-hexyl, etc., p is an integer of 0-3, and q is 1 or 2;

[0035] More preferably, the co-initiator is selected from at least one of C2H5AlCl2, C6H 15 Al2Cl3 (ethyl aluminum sesquichloride), and C4H 10 AlCl.

[0036] Optionally, the micro-crosslinked isobutenyl-based elastomer provided by the present application further comprises a dispersant selected from at least one of dichloromethane, chloromethane, chloroethylene, and chlorohexane; preferably chloromethane.

[0037] The present application further provides a preparation method of the micro-crosslinked isobutenyl-based elastomer as described above, comprising the following steps:

[0038] After mixing the main initiator and the co-initiator, aging is performed at room temperature to -70°C to obtain a complex initiator;

[0039] Under stirring and at -60 to -98°C, the complex initiator is added to a mixed solution of isobutene or isobutene and a conjugated diene, an unsaturated functional monomer, and a dispersant to perform a polymerization reaction, and after the polymerization reaction is completed, a terminating agent is added to terminate the reaction, and the solvent is removed and dried to obtain the micro-crosslinked isobutenyl-based elastomer.

[0040] Optionally, in the preparation method of the micro-crosslinked isobutenyl-based elastomer as described above provided by the present application, the polymerization reaction is performed for 1 to 30 minutes at a temperature of -60 to -98°C.

[0041] Optionally, in the preparation method of the micro-crosslinked isobutenyl-based elastomer as described above provided by the present application, during the preparation of the complex initiator, the mixture formed by mixing the main initiator and the co-initiator is further diluted before aging; dilution with a diluent is not required to meet the implementation of the technical solution of the present application, but the effect after dilution is better, and the present application recommends that the mixture is diluted by ≤10 times with a diluent selected from any one of hexane, cyclohexane, and dichloromethane, as long as the main initiator and the co-initiator can be dissolved and no precipitation occurs.

[0042] Optionally, in the preparation method of the micro-crosslinked isobutenyl-based elastomer as described above provided by the present application, the aging time is not limited, as long as the main initiator and the co-initiator are fully reacted and the active center is not deactivated; the present application recommends that the aging time is 8 to 15 minutes.

[0043] Optionally, in the preparation method of the above micro-crosslinking isobutenyl-based elastomer, the preparation process of the mixed solution of isobutene or isobutene and conjugated diene, unsaturated functional monomer and dispersant is not particularly limited, and each substance can be uniformly dissolved and dispersed in the solvent. The recommended preparation process of the mixed solution of isobutene or isobutene and conjugated diene, unsaturated functional monomer and dispersant is as follows:

[0044] The unsaturated functional monomer is dissolved in a solvent, and then isobutene or isobutene and conjugated diene and dispersant are added and uniformly mixed to obtain the mixed solution of isobutene or isobutene and conjugated diene, unsaturated functional monomer and dispersant. The solvent is not particularly limited, which can dissolve the unsaturated functional monomer and uniformly mix with isobutene or isobutene and conjugated diene and dispersant without layering. In the low-temperature polymerization reaction, the solvent does not solidify.

[0045] Optionally, in the preparation method of the above micro-crosslinking isobutenyl-based elastomer, the preparation of the unsaturated functional monomer includes the following steps:

[0046] Under the action of a catalyst, the dried unsaturated alcohol reacts with diisocyanate in an organic solvent. After the reaction is completed, deionized water is used for dilution, the pH of the system is adjusted to neutral, and the water phase and the organic solvent are removed to obtain the unsaturated functional monomer.

[0047] Optionally, in the preparation method of the above unsaturated functional monomer, the temperature of the amination reaction is 55-85°C, and the time is 6-20h.

[0048] Optionally, in the preparation method of the above unsaturated functional monomer, the dried unsaturated alcohol is 25-35 parts by weight, the diisocyanate is 15-60 parts by weight, the organic solvent is 50-100 parts by weight, and the catalyst is 0.01-0.2 parts by weight.

[0049] Optionally, in the preparation method of the above unsaturated functional monomer, the terminator is a polar substance containing -OH, such as water, alcohol, organic acid or phenol, and preferably methanol and / or ethanol.

[0050] Optionally, in the preparation method of the above unsaturated functional monomer, the way of removing the water phase and the organic solvent is not particularly limited, and the conventional way in the industry can be used. For example, the water phase can be removed by static layering, and the organic solvent can be removed by distillation or vacuum distillation. The organic solvent is not particularly limited, which can dissolve the diisocyanate and be miscible with the unsaturated alcohol without layering. For example, cyclohexane, cyclohexanone, toluene, benzene and xylene.

[0051] Optionally, in the method for preparing the unsaturated functional monomer, the unsaturated alcohol is a C3-C18 unsaturated alcohol containing C=C (alkene); preferably, the unsaturated alcohol is selected from any one of propenyl alcohol, cinnamyl alcohol, 3-buten-1-ol, 4-penten-1-ol, 5-hexen-1-ol, propenyl alcohol, myristic oil alcohol, oleyl alcohol, citronellol, 2-methyl-3-buten-2-ol and 2,3-dimethyl-3-buten-2-ol; more preferably, the unsaturated alcohol is selected from propenyl alcohol, cinnamyl alcohol, citronellol, 3-buten-1-ol or 4-penten-1-ol.

[0052] Optionally, in the method for preparing the unsaturated functional monomer, the diisocyanate is selected from any one of isophorone diisocyanate, toluene diisocyanate, diphenyl methane diisocyanate, dicyclohexyl methane diisocyanate, hexamethylene diisocyanate, lysine diisocyanate, xylylene diisocyanate and tetramethyl m-xylylene diisocyanate; preferably, the diisocyanate is hexamethylene diisocyanate, isophorone diisocyanate, toluene-2,6-diisocyanate or diphenyl methane diisocyanate.

[0053] Optionally, in the method for preparing the unsaturated functional monomer, the catalyst is an auxiliary agent for accelerating the reaction between the isocyanate group in the diisocyanate and the hydroxyl group in the unsaturated alcohol containing alkene; the recommended catalyst in the present application is selected from a tertiary amine catalyst or an organic metal compound catalyst; preferably, the tertiary amine catalyst is selected from any one of pentamethyldiethylene triamine, pentamethyldipropylene triamine, dimethylcyclohexylamine, 1,3,5-tris(dimethylaminopropyl)hexahydrotriazine, 4-dimethylpyridine, dimethylbenzylamine, dimethylethanolamine and tetramethyldipropylene triamine; more preferably, the tertiary amine catalyst is pentamethyldiethylene triamine.

[0054] Preferably, the organic metal compound catalyst is selected from any one of stannous octoate, dibutyl tin dilaurate, zinc isooctoate and zinc bismuth isooctoate; more preferably, the organic metal compound catalyst is dibutyl tin dilaurate.

[0055] Compared with the prior art, the present application has the following beneficial effects:

[0056] 1. The micro-crosslinking isobutenyl elastomer provided by the application increases the crosslinking degree by adding a functional monomer containing an olefin bond, improves the tensile strength and tear strength of the isobutenyl elastomer, and introduces a polar group urethane to improve the processing performance of the isobutenyl elastomer. Specifically, the application first uses diisocyanate and unsaturated alcohol to design and synthesize a monomer with crosslinking function, and then adds the monomer to the polymerization system of the isobutenyl elastomer. The double bond in the monomer participates in the cationic polymerization reaction to generate a crosslinking structure in the isobutenyl elastomer, thereby improving the tensile strength and tear strength of the isobutenyl elastomer. The amino group and ester group are both polar groups, which can improve the processing performance of the isobutenyl elastomer.

[0057] 2. The micro-crosslinking isobutenyl elastomer provided by the application increases the crosslinking structure between polymer molecules by introducing a urethane functional monomer containing an olefin bond to participate in the polymerization reaction in the polymerization process of isobutene or isobutene and conjugated diene, thereby giving the isobutenyl elastomer good mechanical strength, solving the problems of weak green strength and serious storage cold flow of the isobutenyl elastomer, and improving the tensile strength and tear strength. Since the structure of the urethane functional monomer contains a urethane group, which is a polar group, the urethane functional group is introduced into the molecular chain of the isobutenyl elastomer, and the urethane functional group is located between different molecular chains of the isobutenyl elastomer, thereby enhancing the blending ability of the isobutenyl elastomer with other polar rubbers, increasing the interaction between the molecular chains of the isobutenyl elastomer and fillers, and thereby improving the tensile strength and tear strength of the isobutenyl elastomer and the processing performance of the isobutenyl elastomer.

[0058] 3. The preparation method of the micro-crosslinking isobutenyl elastomer provided by the application has great adjustability in the structure and molecular weight of diisocyanate and unsaturated monol alcohol in the synthesis of the urethane functional monomer, so that the performance of the crosslinking isobutenyl elastomer product can be adjusted according to the type and amount of the urethane functional monomer. DETAILED DESCRIPTION

[0059] The application will be specifically described by the following examples. It is necessary to point out here that the following examples are only used to further illustrate the application and cannot be understood as limiting the protection scope of the application. Those skilled in the art can make some non-essential improvements and adjustments to the application according to the above content of the application.

[0060] The specific experimental steps or conditions not specified in the examples and comparative examples can be performed according to the conventional experimental steps described in the literature in the art. The reagents or instruments not specified by the manufacturer are all conventional reagent products that can be obtained by market purchase.

[0061] Source of raw materials or equipment

[0062] Isophorone diisocyanate: Aladdin;

[0063] Toluene-2,6-diisocyanate: Aldrich;

[0064] Hexamethylene diisocyanate: Aldrich;

[0065] Diphenylmethane diisocyanate: Sigma-Aldrich;

[0066] 4-Penten-1-ol: Aldrich;

[0067] 3-Buten-1-ol: Aldrich;

[0068] Propenyl alcohol: Aldrich;

[0069] Cinnamyl alcohol: Aldrich;

[0070] Citronellol: Sigma-Aldrich;

[0071] Dibutyltin dilaurate: Aldrich;

[0072] Stannous octoate: Sigma-Aldrich;

[0073] Pentamethyldiethylenetriamine: Sigma-Aldrich;

[0074] Pentamethyldipropylene triamine: Aldrich;

[0075] Xylene: National Pharmaceutical Group Chemical Reagent Co., Ltd.;

[0076] Benzene: National Pharmaceutical Group Chemical Reagent Co., Ltd.;

[0077] Ethylaluminum sesquichloride: Balingwei Technology Co., Ltd.;

[0078] C2H5AlCl2: Balingwei Technology Co., Ltd.;

[0079] Polytetrahydrofuran diol (PTMG650): BASF;

[0080] Hydroxyl-terminated polybutadiene (Mn, 1500-1700): Zibo Qilong Chemical Co., Ltd.;

[0081] Mixing type polyurethane B60: Guangzhou Huagong Baichuan Science and Technology Co., Ltd.;

[0082] Water-based polyurethane PU630-6, solid content 30%: Taixing Zhongfeng Auxiliary Factory;

[0083] Isobutene: Zhejiang Xinhuixin Material Co., Ltd.;

[0084] Isoprene: PetroChina Lanzhou Petrochemical Company;

[0085] 2,3-dimethyl-1,3-butadiene: Sigma-Aldrich;

[0086] 1,4-pentadiene: Beijing Bailingwei Technology Co., Ltd.;

[0087] cyclohexane: PetroChina Lanzhou Chemical Research Center;

[0088] cyclohexanone: Sigma-Aldrich;

[0089] chloromethane: Zibo Huibao Chemical Co., Ltd.;

[0090] chloroethylene: Zibo Huibao Chemical Co., Ltd.;

[0091] sodium hydroxide: National Pharmaceutical Group Chemical Reagent Co., Ltd.;

[0092] hydrochloric acid: National Pharmaceutical Group Chemical Reagent Co., Ltd.;

[0093] anhydrous ethanol, Beijing Chemical Plant.

[0094] Evaluation and analysis method

[0095] Molecular weight and molecular weight distribution: execute standard GB / T 21863-2008;

[0096] Tensile strength: execute standard GB / T 528-2009;

[0097] Tear strength: execute standard GB / T 529-2008;

[0098] In the following examples and comparative examples, when adjusting pH, 0.1 mol / L sodium hydroxide solution or 0.1 mol / L hydrochloric acid solution was used according to the actual situation.

[0099] Example 1

[0100] This example provides a kind of micro crosslinking isobutene-based elastomer, and its specific preparation method is as follows:

[0101] (1) preparation of unsaturated functional monomer

[0102] Into a clean and closed reaction vessel, 30 parts by weight of dry 4-penten-1-ol and 30 parts by weight of toluene-2, 6-diisocyanate were added, then 50 parts by weight of xylene, 0.03 parts by weight of dibutyl tin dilaurate were added, and the reaction was carried out at 80°C for 6h until the isocyanate group was completely reacted, then it was cooled to room temperature, 100 parts by weight of deionized water was added for dilution, and then the pH of the system was adjusted to neutral with 0.1 mol / L sodium hydroxide solution and 0.1 mol / L hydrochloric acid solution. After standing and separating, the organic phase was separated, and the solvent xylene and the remaining 4-penten-1-ol and other components were separated by distillation to obtain an unsaturated functional monomer-1. The structure was correct after identification by nuclear magnetic resonance and MS, and the specific structure was as follows:

[0103]

[0104] (2) Preparation of micro-crosslinked butyl rubber

[0105] Preparation of complex initiator: 0.7 parts by weight of dichloromethane saturated aqueous solution (containing water 3.5 x 10 -5 parts by weight) and 2.6 parts by weight of C2H5AlCl2 were mixed, diluted 3 times with hexane, and aged at -20°C for 10 min to obtain a complex initiator;

[0106] Preparation of micro-crosslinked butyl rubber: 2 parts by weight of the above unsaturated functional monomer-1 was dissolved in hexane, then 95 parts by weight of isobutene, 5 parts by weight of isoprene, 350 parts by weight of chloromethane were added, mixed uniformly, then the temperature was reduced to -70°C, and the above complex initiator was added under stirring at this temperature for polymerization reaction for 10 min, then anhydrous ethanol was added to terminate the reaction, the solvent was removed by reduced pressure distillation, and vacuum drying was carried out to obtain a micro-crosslinked butyl rubber sample-A1.

[0107] Comparative Example 1

[0108] This comparative example is similar to Example 1, except that in the preparation process of micro-crosslinked butyl rubber in step (2), no unsaturated functional monomer-1 was added. The preparation of butyl rubber provided in this comparative example specifically includes the following steps:

[0109] Preparation of complex initiator: 0.7 parts by weight of dichloromethane saturated aqueous solution (containing water 3.5 x 10 -5 parts by weight) and 2.6 parts by weight of C2H5AlCl2 were mixed, diluted 5 times with hexane, and aged at -20°C for 10 min to obtain a complex initiator;

[0110] Preparation of butyl rubber: 95 parts by weight of isobutene, 5 parts by weight of isoprene, 350 parts by weight of chloromethane were mixed uniformly, then the temperature was reduced to -70℃, and the above complex initiator was added under stirring at this temperature for polymerization reaction for 10 min, then anhydrous ethanol was added to terminate the reaction, the solvent was removed by distillation under reduced pressure, and vacuum drying was performed to obtain butyl rubber sample-B1.

[0111] Example 2

[0112] The present example provides a micro-crosslinked isobutylene-based elastomer, and the specific preparation method is as follows:

[0113] (1) Preparation of unsaturated functional monomer

[0114] 35 parts by weight of dry propenyl alcohol and 45 parts by weight of isophorone diisocyanate were added to a clean and sealed reaction vessel, then 80 parts by weight of benzene, 0.05 parts by weight of dibutyltin dilaurate were added, and the reaction was carried out at 85℃ for 10h until the isocyanate group was completely reacted, then the temperature was reduced to room temperature, 100 parts by weight of deionized water was added for dilution, then the pH of the system was adjusted to neutral with 0.1 mol / L sodium hydroxide solution and 0.1 mol / L hydrochloric acid solution, and then the system was allowed to stand and separate, the organic phase was separated, and the solvent benzene and the remaining propenyl alcohol were separated by distillation to obtain the unsaturated functional monomer-2, which was identified by nuclear magnetic resonance and MS to have the correct structure, and the specific structure is as follows:

[0115]

[0116] (2) Preparation of micro-crosslinked butyl rubber

[0117] Complex initiator: 1.0 parts by weight of hydrogen chloride in dichloromethane solution (HCl concentration is 0.0005 mol / L, HCl is 1.37 x 10 -5 parts by weight) and 3.2 parts by weight of ethyl aluminum sesquichloride were mixed, then diluted 10 times with hexane, and aged at -40℃ for 10 min to obtain the complex initiator;

[0118] Preparation of micro-crosslinked butyl rubber: 0.5 parts by weight of the above unsaturated functional monomer-2 was dissolved in hexane, then 91 parts by weight of isobutene, 9 parts by weight of isoprene, 700 parts by weight of chloroethylene were mixed uniformly, then the temperature was reduced to -85℃, and the above complex initiator was added under stirring at this temperature for polymerization reaction for 20 min, then anhydrous ethanol was added to terminate the reaction, the solvent was removed by distillation under reduced pressure, and vacuum drying was performed to obtain the micro-crosslinked butyl rubber sample-A2.

[0119] Comparative Example 2

[0120] The comparative example is similar to example 2, the only difference is that the unsaturated functional monomer-2 is added after the polymerization of the butyl rubber in step (2), the unsaturated functional monomer-2 does not participate in the polymerization reaction, but participates in the later vulcanization. The preparation of the butyl rubber provided by the comparative example specifically includes the following steps:

[0121] (1) Preparation of unsaturated functional monomer: the same as example 2.

[0122] (2) Preparation of butyl rubber

[0123] Complex initiator: 1.0 parts by weight of hydrogen chloride in dichloromethane solution (HCl concentration is 0.0005 mol / L, HCl is 1.37 x 10 -5 parts by weight) and 3.2 parts by weight of ethyl aluminum sesquichloride are mixed, then diluted 10 times with hexane, and aged at -40°C for 10 min to obtain a complex initiator;

[0124] Preparation of butyl rubber: 91 parts by weight of isobutene, 9 parts by weight of isoprene and 700 parts by weight of chloroethylene are mixed uniformly, then the temperature is reduced to -85°C, and the above complex initiator is added under stirring at this temperature for polymerization reaction for 20 min, then anhydrous ethanol is added to terminate the reaction, then the solution of unsaturated functional monomer-2 (0.5 parts by weight of the above unsaturated functional monomer-2 is dissolved in hexane) is added and mixed uniformly, then the solvent is removed by vacuum distillation, and vacuum drying is performed to obtain a butyl rubber sample-B2.

[0125] Example 3

[0126] The present example provides a micro-crosslinking isobutylene-based elastomer, and the specific preparation method is as follows:

[0127] (1) Preparation of unsaturated functional monomer

[0128] 30 parts by weight of dry cinnamyl alcohol and 20 parts by weight of hexamethylene diisocyanate are added to a clean and sealed reaction vessel, then 60 parts by weight of cyclohexane, 0.1 parts by weight of stannous octoate are added, and the reaction is carried out at 75°C for 16 h until the isocyanate group is completely reacted, then the temperature is reduced to room temperature, 100 parts by weight of deionized water is added for dilution, then the pH is adjusted to neutral with 0.1 mol / L sodium hydroxide solution and 0.1 mol / L hydrochloric acid solution, and then the organic phase is separated by standing and separation, and the solvent cyclohexane and the remaining cinnamyl alcohol and other components are separated by distillation to obtain the unsaturated functional monomer-3, which is identified by nuclear magnetic resonance and MS to have a correct structure, and the specific structure is as follows:

[0129]

[0130] (2) Preparation of micro-crosslinking butyl rubber

[0131] Complex initiator: 1.2 parts by weight of dichloromethane saturated aqueous solution (water is 6 x 10 -5 parts by weight) and 2.8 parts by weight of ethyl aluminum sesquichloride were mixed, then diluted 10 times with cyclohexane, aged for 10 min at -70°C to obtain a complex initiator;

[0132] Preparation of micro-crosslinked butyl rubber: 10 parts by weight of the above unsaturated functional monomer-3 was dissolved in cyclohexane, then 98 parts by weight of isobutene, 2 parts by weight of isoprene, 400 parts by weight of chloromethane were mixed, then the temperature was reduced to -80°C, and the above complex initiator was added under stirring at this temperature for polymerization reaction for 30 min, then anhydrous ethanol was added to terminate the reaction, the solvent was removed by distillation under reduced pressure, and vacuum drying was performed to obtain a micro-crosslinked butyl rubber sample-A3.

[0133] Comparative Example 3

[0134] This comparative example is similar to Example 3, the only difference being that in the preparation process of step (2) micro-crosslinked butyl rubber, 10 parts by mass of water-based polyurethane PU630-6 emulsion is used instead of the solution of unsaturated functional monomer-3. The preparation of butyl rubber provided in this comparative example specifically includes the following steps:

[0135] Complex initiator: 1.2 parts by weight of dichloromethane saturated aqueous solution (water is 6 x 10 -5 parts by weight) and 2.8 parts by weight of ethyl aluminum sesquichloride were mixed, then diluted 10 times with cyclohexane, aged for 10 min at -70°C to obtain a complex initiator;

[0136] Preparation of butyl rubber / polyurethane mixture: 98 parts by weight of isobutene, 2 parts by weight of isoprene, 400 parts by weight of chloromethane were mixed, then the temperature was reduced to -80°C, and the above initiator was added under stirring at this temperature for polymerization reaction for 30 min, then anhydrous ethanol was added to terminate the reaction, then 10 parts by mass of polyurethane PU630-6 emulsion was added and mixed uniformly, then the solvent was removed by distillation under reduced pressure, and vacuum drying was performed to obtain a micro-crosslinked butyl rubber sample-B3.

[0137] Example 4

[0138] This example provides a micro-crosslinked isobutylene-based elastomer, and the specific preparation method is as follows:

[0139] (1) Preparation of unsaturated functional monomer

[0140] 30 parts by weight of dried citronellol and 48 parts by weight of diphenyl methane diisocyanate were added into a clean and sealed reaction vessel, then 60 parts by weight of toluene, 0.15 parts by weight of pentamethyl diethylene triamine were added, and the reaction was carried out at 80°C for 20h until the isocyanate group was completely reacted, then it was cooled to room temperature, 100 parts by weight of deionized water was added for dilution, and then the pH was adjusted to neutral with 0.1mol / L sodium hydroxide solution and 0.1mol / L hydrochloric acid solution, and then it was left to stand and separate, the organic phase was separated, and the solvent toluene and other components were separated by distillation, to obtain an unsaturated functional monomer-4, which was identified by nuclear magnetic resonance and MS to have a correct structure, and the specific structure was as follows:

[0141]

[0142] (2) Preparation of a micro-crosslinked isobutenyl elastomer

[0143] Complex initiator: 1.0 parts by weight of dichloromethane saturated aqueous solution (water is 5×10 -5 parts by weight) and 2.6 parts by weight of ethyl aluminum sesquichloride were mixed, then diluted 5 times with cyclohexane, and aged at -60°C for 10min to obtain a complex initiator;

[0144] Preparation of a micro-crosslinked isobutenyl elastomer: 7 parts by weight of the above unsaturated functional monomer-4 was dissolved in cyclohexane, then 95 parts by weight of isobutene, 5 parts by weight of 2,3-dimethyl-1,3-butadiene, and 400 parts by weight of chloromethane were added, and then the temperature was reduced to -65°C, and the above complex initiator was added for polymerization reaction under stirring at this temperature for 20min, then anhydrous ethanol was added to terminate the reaction, the solvent was removed by distillation under reduced pressure, and then vacuum drying was carried out to obtain a micro-crosslinked isobutenyl elastomer sample-A4.

[0145] Comparative Example 4

[0146] This comparative example is similar to Example 4, except that in the preparation process of the micro-crosslinked isobutenyl elastomer in step (2), the unsaturated functional monomer-4 was not added. The preparation of the isobutenyl elastomer provided in this comparative example specifically includes the following steps:

[0147] Complex initiator: 1.0 parts by weight of dichloromethane saturated aqueous solution (water is 5×10 -5 parts by weight) and 2.6 parts by weight of ethyl aluminum sesquichloride were mixed, then diluted 5 times with cyclohexane, and aged at -60°C for 10min to obtain a complex initiator;

[0148] Preparation of the micro-crosslinking isobutenyl elastomer: 95 parts by weight of isobutene, 5 parts by weight of 2,3-dimethyl-1,3-butadiene, 400 parts by weight of chloromethane were mixed uniformly, then the temperature was reduced to -65°C, and the above complex initiator was added under stirring at this temperature to carry out polymerization reaction for 20 min, then anhydrous ethanol was added to terminate the reaction, the solvent was removed by distillation under reduced pressure, and vacuum drying was carried out to obtain the micro-crosslinking isobutenyl elastomer sample-B4.

[0149] Example 5

[0150] The present example provides a micro-crosslinking isobutenyl elastomer, and the specific preparation method is as follows:

[0151] (1) Preparation of unsaturated functional monomer

[0152] 30 parts by weight of dry 3-buten-1-ol and 60 parts by weight of isophorone diisocyanate were added to a clean and sealed reaction vessel, then 100 parts by weight of cyclohexanone, 0.2 parts by weight of pentamethyl dipropylene triamine were added, and the reaction was carried out at 85°C for 12 h until the isocyanate group was completely reacted, then the temperature was reduced to room temperature, 100 parts by weight of deionized water was added for dilution, then the pH of the system was adjusted to neutral with 0.1 mol / L sodium hydroxide solution and 0.1 mol / L hydrochloric acid solution, and then the system was allowed to stand and separate, the organic phase was separated, and the solvent cyclohexanone and the remaining 3-buten-1-ol and other components were separated by distillation to obtain the unsaturated functional monomer-5, which was identified by nuclear magnetic resonance and MS to have a correct structure, and the specific structure was as follows:

[0153]

[0154] (2) Preparation of the micro-crosslinking isobutenyl elastomer

[0155] Complex initiator: 1.2 parts by weight of hydrogen chloride in dichloromethane solution (HCl concentration was 0.0005 mol / L, and HCl was 1.65 x 10 -5 parts by weight) and 3.5 parts by weight of C2H5AlCl2 were mixed, and then the mixture was aged at room temperature for 10 min to obtain the complex initiator;

[0156] Preparation of the micro-crosslinking isobutenyl elastomer: 0.2 parts by weight of the above unsaturated functional monomer-5 was dissolved in cyclohexane, then 96 parts by weight of isobutene, 4 parts by weight of 1,4-pentadiene, and 600 parts by weight of chloromethane were added, the mixture was uniformly mixed, then the temperature was reduced to -90°C, and the above complex initiator was added under stirring at this temperature to carry out polymerization reaction for 5 min, then anhydrous ethanol was added to terminate the reaction, the solvent was removed by distillation under reduced pressure, and vacuum drying was carried out to obtain the micro-crosslinking isobutenyl elastomer sample-A5.

[0157] Comparative Example 5

[0158] The preparation of the micro-crosslinking isobutenyl elastomer provided by the present comparative example specifically comprises the following steps:

[0159] (1) Preparation of unsaturated functional monomer

[0160] 35 parts by weight of dry polytetramethylene glycol (PTMG650) is mixed with 18 parts by weight of hydroxyl-terminated polybutadiene (Mn, 1500-1700) and 15 parts by weight of isophorone diisocyanate, 100 parts by weight of cyclohexanone is added, 2 drops of dibutyltin dilaurate is added, and after stirring uniformly at 80°C, the temperature is lowered to room temperature, 100 parts by weight of deionized water is added for dilution, and the pH is adjusted to neutral with 0.1 mol / L sodium hydroxide solution and 0.1 mol / L hydrochloric acid solution. After standing and separating, the organic phase is separated, and the solvent cyclohexanone and other components are separated by distillation to obtain the unsaturated functional monomer-B5, and the specific structure is as follows:

[0161]

[0162] (2) Preparation of micro-crosslinking isobutenyl elastomer

[0163] Complex initiator: 1.2 parts by weight of hydrogen chloride in dichloromethane solution (HCl concentration is 0.0005 mol / L, and HCl is 1.65×10 -5 parts by weight) and 3.5 parts by weight of C2H5AlCl2 are mixed, and then aged at room temperature for 10 min to obtain the complex initiator;

[0164] Preparation of micro-crosslinking isobutenyl elastomer: 0.2 parts by weight of the above unsaturated functional monomer-B5 is dissolved in cyclohexane, then 96 parts by weight of isobutene, 4 parts by weight of 1,4-pentadiene, and 600 parts by weight of chloromethane are added, and then the temperature is lowered to -90°C, and the above initiator is added for polymerization reaction under stirring at this temperature for 5 min, and then anhydrous ethanol is added to terminate the reaction. After removing the solvent by reduced pressure distillation and vacuum drying, a micro-crosslinking isobutenyl elastomer sample-B5 is obtained.

[0165] Example 6

[0166] The present example provides a micro-crosslinking isobutenyl elastomer, and the specific preparation method is as follows:

[0167] (1) Preparation of unsaturated functional monomer

[0168] Into a clean and tightly closed reaction vessel, 25 parts by weight of dry cinnamyl alcohol and 25 parts by weight of isophorone diisocyanate were added, followed by 80 parts by weight of toluene, 0.2 parts by weight of stannous octoate, and the reaction was carried out at 60°C for 14 hours until the isocyanate groups were completely reacted. After the reaction mixture was cooled to room temperature, 100 parts by weight of deionized water was added to dilute the reaction mixture, and the pH was adjusted to neutral with 0.1 mol / L sodium hydroxide solution and 0.1 mol / L hydrochloric acid solution. After the reaction mixture was allowed to stand and separated, the organic phase was separated, and the solvent toluene and the remaining cinnamyl alcohol were distilled off to obtain an unsaturated functional monomer-6. The structure of the obtained unsaturated functional monomer-6 was identified by nuclear magnetic resonance and mass spectrometry, and the structure was correct. The specific structure is as follows:

[0169]

[0170] (2) Preparation of a micro-crosslinked isobutenyl elastomer

[0171] Complex initiator: 2.5 parts by weight of dichloromethane saturated aqueous solution (containing 1.25 x 10 -4 parts by weight of water) and 3.0 parts by weight of ethyl aluminum sesquichloride were mixed, and then diluted with cyclohexane by 8 times. The mixture was aged at -60°C for 10 minutes to obtain a complex initiator.

[0172] Preparation of a micro-crosslinked isobutenyl elastomer: 5 parts by weight of the above unsaturated functional monomer-6 was dissolved in cyclohexane, and then 100 parts by weight of isobutene and 300 parts by weight of chlorohexane were added. After the mixture was uniformly mixed, the temperature was reduced to -98°C, and the above complex initiator was added at the temperature and under stirring conditions for polymerization reaction for 15 minutes. After the reaction was terminated by adding anhydrous ethanol, the solvent was removed by distillation under reduced pressure, and the product was vacuum dried to obtain a micro-crosslinked isobutenyl elastomer sample-A6.

[0173] Comparative Example 6

[0174] This comparative example is similar to Example 6, except that in the preparation of the micro-crosslinked isobutenyl elastomer in step (2), the unsaturated functional monomer-6 was not added. The preparation of the isobutenyl elastomer provided in this comparative example specifically includes the following steps:

[0175] Complex initiator: 2.5 parts by weight of dichloromethane saturated aqueous solution (containing 1.25 x 10 -4 parts by weight of water) and 3.0 parts by weight of ethyl aluminum sesquichloride were mixed, and then diluted with cyclohexane by 8 times. The mixture was aged at -60°C for 10 minutes to obtain a complex initiator.

[0176] Preparation of an isobutenyl elastomer: 100 parts by weight of isobutene and 300 parts by weight of chlorohexane were mixed, and then the temperature was reduced to -98°C. The above initiator was added at the temperature and under stirring conditions for polymerization reaction for 15 minutes. After the reaction was terminated by adding anhydrous ethanol, the solvent was removed by distillation under reduced pressure, and the product was vacuum dried to obtain an isobutenyl elastomer sample-B6.

[0177] Performance test

[0178] The elastomer samples prepared in each of the above examples and Comparative Examples 1-3, 5-6 were mixed with the auxiliaries (ZnO, aromatic oil, carbon black and accelerator) at 45°C, and then powder sulfur S was added to vulcanize and form a composite material, according to the formula in Table 1. The standard used was GB / T 6038-2006.

[0179] The butyl rubber sample prepared in Comparative Example 4 was mixed with the auxiliaries (ZnO, aromatic oil, carbon black, accelerator and 7 parts by weight of mixing type polyurethane B60), and then powder sulfur S was added to vulcanize and form a composite material, according to the formula in Table 1.

[0180] The composite materials prepared were respectively tested according to the national standards GB / T 528-2009 and GB / T 529-2008 to form test samples and perform testing. The specific test results are shown in Table 2.

[0181] Table 1 Formula of the rubber (parts by mass)

[0182] No. Raw material name Formulation (mass parts) Raw material category 1 Butyl rubber sample 100 Synthetic rubber 2 ZnO 3 Activator 3 Aromatic hydrocarbon oil 24 Process oil 4 Carbon black 50 Reinforcing agent 5 S 1.76 Vulcanizing agent 6 Accelerator TMTD 1.8 Accelerator

[0183] Table 2 Test results

[0184]

[0185]

[0186] As can be seen from the data in the above table, the introduction of a functional monomer having cross-linking function, containing an alkene bond and a urethane group, into the isobutenyl elastomer molecule can improve the tensile strength and tear strength of the isobutenyl elastomer, and improve the processing performance of the isobutenyl elastomer. Specifically, as can be seen from the comparison of Example 1 and Comparative Example 1, Example 4 and Comparative Example 4, and Example 6 and Comparative Example 6, the addition of a urethane group-containing molecule having cross-linking function during polymerization improves the processing performance of the isobutenyl elastomer.

[0187] As can be seen from the comparison of Example 2 and Comparative Example 2, the addition of a urethane group-containing molecule having cross-linking function after the polymerization of isobutene and isoprene does not achieve the purpose of improving the processing performance;

[0188] As can be seen from the comparison of Comparative Example 3 and Example 3, the addition of a polyurethane emulsion after the polymerization of isobutene and isoprene does not achieve the purpose of improving the processing performance.

[0189] As can be seen from the comparison of Example 5 and Comparative Example 5, the use of a low molecular weight dihydroxy compound to prepare a urethane group-containing polymer does not achieve the purpose of improving the processing performance.

[0190] Anti-cold flow performance test method: at room temperature, the same mass of sample is loaded into the mold and compacted, the height of the rubber block is measured after taking out and the data is recorded as h0, and the sample height data h is recorded after a period of time i , the sample height change rate at different times is calculated, and the anti-cold flow performance of the sample is judged. In the present application, the sample height change after 5 days and 10 days is mainly tested to characterize the anti-cold flow performance of the sample.

[0191] Anti-cold flow performance (%) = (h0-h i ) / h0x100%

[0192] Table 3 Anti-cold flow performance test results

[0193] Cold flow resistance (%), 5 days Cold flow resistance (%), 10 days Example 1 96.2 91.2 Comparative Example 1 92.3 81.9 Example 2 94.5 90.2 Comparative Example 2 90.2 79.6 Example 3 92.3 87.5 Comparative Example 3 89.2 81.1 Example 4 93.2 89.4 Comparative Example 4 92.2 81.2 Example 5 93.5 86.7 Comparative Example 5 89.2 78.6 Example 6 92.8 86.7 Comparative Example 6 90.4 76.4

[0194] From the data comparison in the above table, it can be seen that the micro-crosslinking isobutenyl elastomer provided by the present application can improve the processing performance of the isobutenyl elastomer by introducing a functional monomer containing a carbon-carbon double bond and a urethane group molecule with crosslinking function in the polymerization process, and the cold flow speed is also significantly reduced.

[0195] Of course, the present application can also have other various embodiments, and those skilled in the art can make various corresponding changes and modifications according to the present application without departing from the spirit and essence of the present application. However, these corresponding changes and modifications should all belong to the protection scope of the claims of the present application.

Claims

1. A micro-crosslinked isobutylene-based elastomer, characterized in that, The product comprises, by weight, the following raw materials: 0.1–10 parts of unsaturated functional monomers, 100 parts of isobutylene and conjugated diene, and 1.3 × 10⁻⁶ main initiator. -5 ~1.3×10 -4 The total amount of initiator is 2.4 to 3.5 parts, and the total amount of dispersant is 300 to 800 parts; Wherein, the isobutylene is 90-100 parts and the conjugated diene is 0-10 parts; The unsaturated functional monomer has the structure shown in Formula I: Formula I n is an integer from 0 to 10, m is an integer from 0 to 5, and z is an integer from 0 to 10, and n and z cannot be 0 at the same time; R' and R” are each independently selected from H, C6-C10 aryl, or C1-C5 straight-chain or branched alkyl; R is selected from unsubstituted or substituted phenylene, C1-C10 straight-chain or branched alkylene, unsubstituted or substituted... C6-C12 cycloalkylene compounds, R”' is selected from C1-C5 straight-chain or branched alkyl groups.

2. The micro-crosslinked isobutylene-based elastomer as described in claim 1, characterized in that, n is an integer from 0 to 5, m is an integer from 0 to 3, and z is an integer from 0 to 5; R' and R” are each independently selected from H, phenyl, or methyl; R”' is selected from methyl, ethyl or butyl; R is selected from 3. The micro-crosslinked isobutylene-based elastomer as described in claim 1, characterized in that, The conjugated diene is selected from straight-chain or branched C4-C8 dienes.

4. The micro-crosslinked isobutylene-based elastomer as described in claim 1, characterized in that, The main initiator is selected from at least one of water, inorganic acid and tertiary alkyl halide.

5. The micro-crosslinked isobutylene-based elastomer as described in claim 1, characterized in that, The co-initiator is selected from metal halide salts, organoaluminum compounds, BF3, or BCl3.

6. The micro-crosslinked isobutylene-based elastomer according to claim 1, characterized in that, The dispersant is selected from at least one of dichloromethane, chloromethane, vinyl chloride, and chlorohexane.

7. The micro-crosslinked isobutylene-based elastomer as described in claim 3, characterized in that, The conjugated diene is selected from C4-C6 dienes.

8. The micro-crosslinked isobutylene-based elastomer as described in claim 7, characterized in that, The conjugated diene is selected from any one of isoprene, 2,3-dimethyl-1,3-butadiene, and 1,4-pentadiene.

9. The micro-crosslinked isobutylene-based elastomer as described in claim 4, characterized in that, The inorganic acid is selected from any one of HCl, HBr, HF, HClO4, HClSO3, H2SO4, and H3PO4.

10. The micro-crosslinked isobutylene-based elastomer as described in claim 9, characterized in that, The main initiator is selected from water and / or HCl.

11. The micro-crosslinked isobutylene-based elastomer as described in claim 5, characterized in that, The halide metal salt is selected from at least one of BeCl2, ZnCl2, CdCl2, HgCl2, AlCl3, AlBr3, SnCl4, TiCl4, TiBr4, ZrCl4, VCl4, WCl5, and FeCl3.

12. The micro-crosslinked isobutylene-based elastomer as described in claim 5, characterized in that, The co-initiator is selected from C2H5AlCl2, C6H 15 Al2Cl3 and C4H 10 At least one of AlCl.

13. The micro-crosslinked isobutylene-based elastomer as described in claim 6, characterized in that, The dispersant is chloromethane.

14. A method for preparing the micro-crosslinked isobutylene-based elastomer according to any one of claims 1-13, characterized in that, Includes the following steps: The main initiator and co-initiator are mixed and aged at room temperature to -70°C to obtain a complex initiator; Under stirring conditions and at -60 to -98°C, the complexing initiator is added to a mixed solution of isobutylene or isobutylene and conjugated diene, unsaturated functional monomer and dispersant to carry out a polymerization reaction. After the polymerization reaction is completed, a terminator is added to terminate the reaction, the solvent is removed and the mixture is dried to obtain a micro-crosslinked isobutylene-based elastomer.

15. The preparation method according to claim 14, characterized in that, The polymerization reaction takes 1 to 30 minutes and is carried out at a temperature of -60 to -98°C.

16. The preparation method according to claim 14, characterized in that, The preparation process of the complexing initiator includes a step of diluting the mixture formed by mixing the main initiator and the co-initiator before aging.

17. The preparation method according to claim 14, characterized in that, The preparation of the unsaturated functional monomer includes the following steps: Under the action of a catalyst, a dry unsaturated alcohol and a diisocyanate are reacted in an organic solvent. After the reaction is completed, the aqueous phase and the organic solvent are removed to obtain the unsaturated functional monomer.

18. The preparation method according to claim 17, characterized in that, The reaction is carried out at a temperature of 55–85°C for a duration of 6–20 hours.

19. The preparation method according to claim 17, characterized in that, The dry unsaturated alcohol comprises 25-35 parts by weight, the diisocyanate comprises 15-60 parts by weight, the organic solvent comprises 50-100 parts by weight, and the catalyst comprises 0.01-0.2 parts by weight.

20. The preparation method according to claim 17, characterized in that, The unsaturated alcohol is a C3-C18 unsaturated alcohol containing C=C.

21. The preparation method according to claim 17, characterized in that, The diisocyanate is selected from any one of isophorone diisocyanate, toluene diisocyanate, diphenylmethane diisocyanate, and hexamethylene diisocyanate.

22. The preparation method according to claim 17, characterized in that, The catalyst is selected from tertiary amine catalysts or organometallic compound catalysts; the tertiary amine catalyst is selected from any one of pentamethyldiethylenetriamine, pentamethyldipropylenetriamine, dimethylcyclohexylamine, 1,3,5-tris(dimethylaminopropyl)hexahydrotriazine, 4-dimethylaminopyridine, dimethylbenzylamine, dimethylethanolamine and tetramethyldipropylenetriamine; The organometallic catalyst is selected from any one of stannous octoate, dibutyltin dilaurate, zinc isooctanoate, and bismuth isooctanoate.

23. The preparation method according to claim 16, characterized in that, Dilute with a diluent ≤10 times, wherein the diluent is selected from any one of hexane, cyclohexane and dichloromethane.

24. The preparation method according to claim 20, characterized in that, The unsaturated alcohol is selected from any one of cinnamyl alcohol, allyl alcohol, 3-buten-1-ol, 4-penten-1-ol, 5-hexen-1-ol, myristyl alcohol, oleyl alcohol, citronellol, 2-methyl-3-buten-2-ol and 2,3-dimethyl-3-buten-2-ol.

25. The preparation method according to claim 24, characterized in that, The unsaturated alcohol is selected from allyl alcohol, cinnamyl alcohol, citronellol, 3-buten-1-ol or 4-penten-1-ol.

26. The preparation method according to claim 21, characterized in that, The diisocyanate is hexamethylene diisocyanate, isophorone diisocyanate, toluene-2,6-diisocyanate, or diphenylmethane diisocyanate.

27. The preparation method according to claim 22, characterized in that, The tertiary amine catalyst is pentamethyldiethylenetriamine.

28. The preparation method according to claim 22, characterized in that, The organometallic catalyst is dibutyltin dilaurate.

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