A copolymer of isobutylene, alloocimene and its derivatives and preparation method thereof

Abstract

The present invention provides a copolymer of isobutylene, alloocimene and its derivatives and a preparation method thereof. In the copolymer system, the content of isobutylene monomer is 50-99%, the content of alloocimene and its derivatives is 1-50%, and the hardness range of the copolymer is 45-85A. The present invention provides a copolymer of isobutylene, alloocimene and its derivatives having a wide hardness range and can meet more application requirements.

Description

Technical Field

[0001] The invention relates to the field of polymer materials, and more particularly to a copolymer of isobutylene, alloocimene and derivatives thereof and a preparation method thereof. Background Art

[0002] As an indispensable and important synthetic polymer in the chemical industry, the design and research of polyisobutylene and polyisobutylene-based copolymers have always been an important topic. Polyisobutylene (PIB) is a linear homopolymer obtained by cationic polymerization of isobutylene, and its relative molecular weight can range from hundreds to millions. Among them, low molecular weight and high activity polyisobutylene is a high-quality raw material for synthetic lubricant additives, and is also widely used in ashless dispersants, gasoline detergents, emulsifiers for emulsified explosives and other fields. High relative molecular weight polyisobutylene has good ozone resistance, corrosion resistance, acid and alkali resistance, UV aging resistance, as well as excellent air tightness and damping properties. It occupies a large market share in pillar fields such as transportation, chemical production, and medicine. It has a wide range of applications and the demand continues to grow.

[0003] Among polyisobutylene copolymers and their derivatives, butyl rubber is the earliest, most widely used and most deeply studied. Butyl rubber is a linear polymer obtained by cationic polymerization of isobutylene (IB) and a small amount (generally less than 2.7 mol%) of isoprene (IP) at low temperature. The molecular chain of butyl rubber is mainly composed of isobutylene chain ends connected in a head-to-tail manner, and many dense side methyl groups are arranged in a spiral around the main chain, which has large steric hindrance and strong intramolecular friction, so that butyl rubber has good air density and damping properties. In theory, there are three types of isoprene addition: 1,4-addition, 1,2-addition and 3,4-addition, but 1,4-addition is the main one, and there is almost no 3,4-addition structure. Isoprene only accounts for 1% to 2.5% of the main chain in butyl rubber, which shows that the unsaturation of butyl rubber is relatively low. Therefore, butyl rubber has good aging resistance, chemical resistance and water resistance. At the same time, it also has the problems of slow vulcanization speed, poor adhesion with other unsaturated diene rubbers (such as natural rubber, styrene-butadiene rubber, butadiene rubber, etc.), and difficulty in blending or co-vulcanization.

[0004] Several other major products of polyisobutylene copolymers and their derivatives include poly(styrene-b-isobutylene) block copolymers, brominated isobutylene-p-methylstyrene copolymers, poly(tetrahydrofuran-b-isobutylene) block copolymers, etc. Poly(styrene-b-isobutylene) block copolymers have high stability and low rejection reaction, and have high application value in the medical field; brominated isobutylene-p-methylstyrene copolymers have the excellent air tightness and dynamic damping properties of butyl rubber, as well as excellent heat resistance and weather resistance, and have good application prospects in the tire industry; poly(tetrahydrofuran-b-isobutylene) block copolymers have a supramolecular network structure and excellent self-healing properties, and can be used in biomedicine, intelligent repair and other fields.

[0005] α-Pinene is the main extract of pine needles, belongs to the monoterpene class, and is an important raw material for synthetic fragrances. Its main thermal cracking products and derivatives include polyenes such as cymene, citronellal, ocimene, alloocimene and myrcene. Among them, alloocimene is 2,6-dimethyl-2,4,6-octatriene, which exists naturally in essential oils such as geranium oil. In industry, it is mainly obtained by thermal cracking and isomerization of α-pinene, and is a good green renewable raw material.

[0006] In order to expand the product types of polyisobutylene-based copolymers and expand the application fields of α-pinene thermal cracking and its derivatives, researchers have been actively exploring. For example, Guo Tingqiao et al. found that the three double bond structure makes allo-ocimene have a higher reactivity. When it is cationic copolymerized with isobutylene, the reactivity rate is higher than that of isobutylene, and it tends to be homopolymerized, obtaining a block copolymer of allo-ocimene and isobutylene, and multi-block copolymers can be obtained by adjusting the feed ratio (Depascual Teresa J, CA, 1979, 89, 163752y; Guo Tingqiao, Hu Zhongqin, Liu Xianghuan, Yan Baisen, Liu Jianjun. Forest Products Chemical Industry Newsletter, 1996, 6: 15-18); Gergely AL et al. found that the diblock copolymer of isobutylene and alloocimene has stretch-induced crystallization behavior, with a strength of up to 6 MPa and an elongation at break of up to 1000%. At the same time, the structure of the three double bonds of the alloocimene monomer makes the copolymer have a high double bond content. In the theoretical polymerization product, alloocimene mainly exists in the main chain of the macromolecule in the form of 4,7 bonds, so that there is a double bond in the main chain and a double bond hanging in the side chain. It is a thermoplastic elastomer with certain application prospects (Puskas JE, Gergely AL, Kaszas G. Controlled / living carbocationic copolymerization of isobutylene with alloocimene[J]. Polym. Sci. A Polym. Chem, 2012, 51: 29-33; Gergely AL, Turkarslan O, Puskas J E. The role of electron pairdonors in the carbocationic copolymerization of isobutylene with alloocimene[J]. Polym. Sci. Part A:Polym.Chem.,2013,51(22):4717-4721;Gergely AL,Puskas JE.Synthesis and characterization of thermoplastic elastomers withpolyisobutylene and polyalloocimene blocks[J].Polym.Sci.Part A:Polym.Chem.,2015,53(13):1567-1574.).

[0007] Under this technical background, under the same vulcanization formula and processing conditions, if you want to broaden the hardness range of isobutylene and alloocimene copolymers, you can only do so by adjusting the amount of alloocimene during copolymerization to change the double bonds, conjugated double bond content and the structure of the copolymer from a microscopic perspective. However, as a cracking product of α-pinene, alloocimene has extremely high preparation costs, complex preparation processes and scarce raw material sources. It is not appropriate to broaden the hardness range by adjusting the amount of alloocimene. Moreover, most applications require a certain double bond content and a certain vulcanization formula for the copolymer, and changes in the amount of alloocimene and the vulcanization formula are not allowed. Therefore, it is necessary to explore a new method to broaden the hardness range of isobutylene and alloocimene copolymers. Summary of the invention

[0008] In order to solve the above problems, the present invention provides a copolymer of isobutylene, alloocimene and derivatives thereof and a preparation method thereof. The copolymer has a wider hardness range and can meet more application requirements.

[0009] Firstly, one of the objects of the present invention is to provide a copolymer of isobutylene, alloocimene and derivatives thereof.

[0010] Specifically, in the copolymer system, the content of isobutylene monomer is 50-99%, the content of alloocimene and its derivatives is 1-50%, the weight average molecular weight of the copolymer is greater than 100kg / mol, preferably greater than 150kg / mol; the double bond content is higher than 5mol%, preferably higher than 10mol%; the gel content is lower than 8wt%, preferably lower than 5wt%; the hardness range is 45-85A. Further, the alloocimene derivative is one of cymene, citronellal, ocimene, myrcene, and 2,3-dimethyl-1,3-butadiene.

[0011] Secondly, the second object of the present invention is to provide a method for preparing the copolymer of isobutylene and alloocimene and their derivatives.

[0012] The following steps are involved:

[0013] Isobutylene, alloocimene and their derivatives are prepared by cationic polymerization in a solvent under the action of an initiator.

[0014] Furthermore, the preparation method can be achieved in two different ways, as follows:

[0015] Method 1:

[0016] Isobutylene and the first batch of alloocimene and its derivatives are added to a solvent, and then an initiator is added to initiate a polymerization reaction, and then the remaining alloocimene and its derivatives are added in batches or drop by drop until the reaction is completed.

[0017] It is worth mentioning that the present invention uses preparation method 1 to obtain a copolymer with lower hardness. Specifically, when alloocimene and its derivatives are copolymerized with isobutylene, the reactivity ratio is higher than that of isobutylene and is biased towards homogeneous polymerization, and it is easy to form obvious crystals. Therefore, when the total content of the unit structure of alloocimene and its derivatives is certain, it is necessary to make the unit structure of the copolymer as randomly arranged as possible, that is, to destroy the crystalline structure as much as possible. Therefore, in the polymerization stage, by making alloocimene and its derivatives always at a low content in the copolymerization system during the reaction process, the homopolymer chain length can be effectively shortened and the homopolymer chain molecular weight can be reduced to reduce the hardness of the material.

[0018] The method of the present invention comprises the following steps: firstly adding isobutylene and a certain amount of alloocimene and its derivatives into a polymerization system, then adding a corresponding amount of initiator to initiate polymerization, and then adding the remaining alloocimene cracked product and its derivatives in batches or dropwise until the reaction is completed.

[0019] Specifically, the mass fraction of isobutylene monomer in the solvent is 5-20wt%, preferably 10-15wt%; the amount of alloocimene and its derivatives is 2-20% of the total molar content of the copolymer monomers, preferably 3-12%; wherein, the amount of the first batch of alloocimene and its derivatives added is 1-80% of the total amount of alloocimene and its derivatives, preferably 1-30%, more preferably 1-20%, and the more alloocimene and its derivatives added first, the more significant the crystallization phenomenon; after the initiator is added to react for 1s-20min, preferably 1-10min, more preferably 1-5min, the remaining alloocimene and its derivatives are added in batches or drop by drop; wherein, the remaining alloocimene and its derivatives are divided into 3-8 equal parts and added to the reaction system in batches, and the addition time of the remaining alloocimene and its derivatives is controlled to be completed within 1-20min, preferably 1-10min, more preferably 2-8min.

[0020] Method 2:

[0021] Isobutylene, alloocimene and its derivatives, and a crosslinking agent are added into a solvent, and then an initiator is added to initiate a polymerization reaction until the reaction is completed.

[0022] It is worth mentioning that the present invention utilizes preparation method 2 to obtain a copolymer with higher hardness. Specifically, when the total content of unit structures of alloocimene and its derivatives is certain, a cross-linking agent is added to allow the homopolymer chains with high double bond content to be pre-cross-linked during the polymerization stage. The copolymer has a cross-linked structure rather than a linear polymer structure, and the block structure is arranged more closely, thereby strengthening the crystal structure and improving the hardness of the material.

[0023] The second method of the present invention first adds isobutylene and all alloocimenes and derivatives thereof into a polymerization system, then adds a crosslinking agent, and finally adds an initiator of a corresponding content to initiate polymerization.

[0024] Specifically, the mass fraction of isobutylene monomer in the solvent is 5-20wt%, preferably 10-15wt%; the amount of alloocimene and its derivatives is 2-20% of the total molar content of the copolymer monomers, preferably 3-12%; the amount of the crosslinking agent is 0.03-5% of the mass fraction of isobutylene, preferably 0.03-3%; the crosslinking agent is one of divinylbenzene, diisopropenylbenzene, divinyltoluene, 1,5-hexadiene, 1,6-heptadiene, and 1,7-octadiene, preferably divinylbenzene.

[0025] Furthermore, in the cationic polymerization reaction, the solvent is a halogenated hydrocarbon or an isomer of a halogenated hydrocarbon, preferably one or a combination of monochloromethane and dichloromethane.

[0026] Further, the initiator comprises a combination of at least one catalyst and at least one proton source; the catalyst is an alkyl aluminum halide, an aluminum chloride-derived catalyst or a Lewis acid, preferably one of aluminum trichloride, ethylaluminum dichloride, diethylaluminum chloride, dimethylaluminum chloride, and boron trichloride; the amount of the catalyst is 0.5 to 5‰ of the molar amount of isobutylene monomer, preferably 1 to 3‰; the proton source is one or a combination of water, hydrogen chloride, and carboxylic acid; the amount of the proton source is 0.1 to 3‰ of the molar amount of isobutylene monomer; preferably, the initiator is a combination of ethylaluminum dichloride and hydrogen chloride.

[0027] Furthermore, in the cationic polymerization reaction, the polymerization temperature is -120°C to -20°C, preferably -100°C to -0°C, and more preferably -95°C to -10°C; the polymerization pressure is 0.1 bar to 4 bar; the polymerization time is 1 s to 60 min; preferably 1 to 40 min, and more preferably 1 to 30 min.

[0028] Furthermore, after the polymerization reaction is completed, a solvent needs to be added to terminate the reaction, and then the binary copolymer is obtained through desolvation and drying. Among them, the solvent is preferably ethanol.

[0029] Compared with the prior art, the present invention has the following beneficial effects:

[0030] The copolymer of isobutylene, alloocimene and derivatives thereof provided by the present invention can adjust the structural state in the copolymer while maintaining low cost and high efficiency by improving the polymerization process and adding a cross-linking agent, so that the copolymer can obtain a copolymer material with a wider hardness range under the same vulcanization formula and the same processing conditions. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 The NMR spectrum of the copolymer prepared in Example 1 of the present invention;

[0032] Figure 2The DSC curves of the copolymers prepared in Examples 1 and 2 of the present invention;

[0033] Figure 3 The NMR spectrum of the copolymer prepared in Comparative Example 1 of the present invention;

[0034] Figure 4 The DSC curve of the copolymer prepared in Comparative Example 1 of the present invention;

[0035] Figure 5 This is the NMR spectrum of the copolymer prepared in Example 5 of the present invention;

[0036] Figure 6 This is the DSC curve of the copolymer prepared in Example 5 of the present invention. DETAILED DESCRIPTION

[0037] The present invention is described in detail below in conjunction with specific embodiments and drawings. It is necessary to point out that the following embodiments are only used to further illustrate the present invention and cannot be understood as limiting the scope of protection of the present invention. Some non-essential improvements and adjustments made to the present invention by those skilled in the art based on the content of the present invention still fall within the scope of protection of the present invention.

[0038] Example 1

[0039] The total molar ratio of the comonomer isobutylene to alloocimene is 95 / 5. At -95°C and under the protection of high-purity nitrogen, with chloroform as solvent, a chloroform solution of isobutylene (IB) (the mass fraction of IB is 10%) and 30% alloocimene are sequentially added into a low-temperature polymerization reactor. After uniform mixing, a dichloromethane initiator solution of ethylaluminum dichloride (the amount of ethylaluminum dichloride is 1‰ of the molar amount of the comonomer isobutylene) and hydrogen chloride (the amount of hydrogen chloride is 0.05‰ of the molar amount of the comonomer isobutylene) is added to initiate the monomer copolymerization reaction. From the first minute after the initiator is added, the remaining 70% of alloocimene is added in three equal parts within the next 9 minutes, and the total reaction time is 10 minutes. After the reaction is completed, a white emulsion is obtained, and the reaction is terminated with 20 ml of anhydrous ethanol. After the polymer product is desolventized, it is placed in a 40°C vacuum oven and dried for 48 hours, and the yield of the obtained copolymer is 55.4%. The fully dried product was tested and the weight average molecular weight (Mw) of the copolymer was found to be 4.36×10 5 g / mol, the molecular weight distribution index (Mw / Mn) is 1.44, the unsaturation degree is 7.3%, wherein the content of alloocimene is 3.65%, the content of isobutylene is 96.35%, and no gel component is detected in the copolymer.

[0040] Combination Figure 1 and Figure 2It can be seen that the copolymer of isobutylene and alloocimene is obtained in this example, and the copolymer has no high-temperature melting peak, which indicates that the copolymer obtained in this example is not easy to crystallize.

[0041] The weight average molecular weight (Mw) and molecular weight distribution index (MWD) of the copolymer were determined by gel permeation chromatography (GPC) using tetrahydrofuran as solvent; the unsaturation of the copolymer was determined by hydrogen nuclear magnetic resonance ( 1 The gel content of the copolymer was determined by the method specified in "SH / T 1050 Determination of gel content of synthetic raw rubber".

[0042] Furthermore, the copolymer and the common formula were used for vulcanization treatment and then hardness test was performed. Specifically, the mass fractions of each component were as follows:

[0043]

[0044] The preparation process is as follows:

[0045] The isobutylene and alloocimene copolymer was transferred to an open mill, and the mixing temperature was set to 50°C and the mixing speed was set to 22r / min. After plasticizing for 2 minutes, fillers, stearic acid, accelerators and vulcanizers were added in sequence and mixed for 10 minutes to obtain tablets. After standing for 24 hours, the positive vulcanization time was measured to be 31 minutes by a vulcanizer, and the tablets were vulcanized in a 155°C flat plate vulcanizer to obtain sulfide. After standing for 24 hours, the Shore D hardness of the sulfide was measured to be 53.

[0046] Among them, the hardness of the copolymer is measured after unified processing using the method specified in "GBT531.1-2008 Vulcanized Rubber or Thermoplastic Rubber Indentation Hardness Test Method Shore Hardness (Shore Hardness)".

[0047] Example 2

[0048] The total molar ratio of the comonomer isobutylene to alloocimene is 95 / 5. At -95°C and under the protection of high-purity nitrogen, with chloroform as solvent, a chloroform solution of isobutylene (IB) (the mass fraction of IB is 10%) and 30% alloocimene are sequentially added into a low-temperature polymerization reactor. After uniform mixing, ethyl aluminum dichloride (the amount of ethyl aluminum dichloride is 1‰ of the molar amount of the comonomer isobutylene) and a dichloromethane initiator solution of hydrogen chloride (the amount of hydrogen chloride is 0.05‰ of the molar amount of the comonomer isobutylene) are added to initiate the monomer copolymerization reaction. From the first minute after the initiator is added, the remaining 70% of alloocimene is continuously added dropwise until all is added, and the total reaction time is 10 minutes. After the polymerization reaction is completed, a white emulsion is obtained, and the reaction is terminated with 20 ml of anhydrous ethanol. After the polymer product is desolventized, it is placed in a 40°C vacuum oven and dried for 48 hours, and the yield of the obtained copolymer is 48.7%. The fully dried product was tested and the weight average molecular weight (Mw) of the copolymer was found to be 3.82×10 5 g / mol, the molecular weight distribution index (Mw / Mn) was 2.22, the unsaturation degree was 6.5%, among which the content of alloocimene was 3.25%, the content of isobutylene was 96.75%, and no gel component was detected.

[0049] Depend on Figure 2 It can be seen that the copolymer obtained in this example has no high-temperature melting peak, which means that the copolymer is not easy to crystallize.

[0050] Furthermore, the copolymer was vulcanized by the same vulcanization method as in Example 1, and the hardness was tested. The Shore D hardness of the sulfide was 51.

[0051] Example 3

[0052] The total molar ratio of the comonomer isobutylene to alloocimene is 95 / 5. At -95°C and under the protection of high-purity nitrogen, with chloroform as solvent, a chloroform solution of isobutylene (IB) (the mass fraction of IB is 15%) and 30% alloocimene are sequentially added into a low-temperature polymerization reactor. After uniform mixing, ethyl aluminum dichloride (the amount of ethyl aluminum dichloride is 1‰ of the molar amount of the comonomer isobutylene) and a dichloromethane initiator solution of hydrogen chloride (the amount of hydrogen chloride is 0.05‰ of the molar amount of the comonomer isobutylene) are added to initiate the monomer copolymerization reaction. From the first minute after the initiator is added, the remaining 70% of alloocimene is continuously added dropwise until all is added, and the total reaction time is 10 minutes. After the polymerization reaction is completed, a white emulsion is obtained, and the reaction is terminated with 20 ml of anhydrous ethanol. After the polymer product is desolventized, it is placed in a 40°C vacuum oven and dried for 48 hours, and the yield of the obtained copolymer is 60.7%. The fully dried product was tested and the weight average molecular weight (Mw) of the copolymer was found to be 4.18×10 5g / mol, the molecular weight distribution index (Mw / Mn) was 3.16, the unsaturation degree was 7.9%, among which the content of alloocimene was 3.95%, the content of isobutylene was 96.05%, and no gel component was detected.

[0053] Furthermore, the copolymer was vulcanized by the same vulcanization method as in Example 1, and the hardness was tested. The Shore A hardness of the sulfide was 53.

[0054] Example 4

[0055] The total molar ratio of the comonomer isobutylene to alloocimene is 95 / 5. At -95°C and under the protection of high-purity nitrogen, with chloroform as solvent, a chloroform solution of isobutylene (IB) (the mass fraction of IB is 10%) and 20% alloocimene are sequentially added into a low-temperature polymerization reactor. After uniform mixing, a dichloromethane initiator solution of ethylaluminum dichloride (the amount of ethylaluminum dichloride is 1‰ of the molar amount of the comonomer isobutylene) and hydrogen chloride (the amount of hydrogen chloride is 0.05‰ of the molar amount of the comonomer isobutylene) is added to initiate the monomer copolymerization reaction. From the first minute after the initiator is added, the remaining 80% of alloocimene is continuously added dropwise until all is added, and the total reaction time is 10 minutes. After the polymerization reaction is completed, a white emulsion is obtained, and the reaction is terminated with 20 ml of anhydrous ethanol. After the polymer product is desolventized, it is placed in a 40°C vacuum oven and dried for 48 hours, and the yield of the obtained copolymer is 58.4%. The fully dried product was tested and the weight average molecular weight (Mw) of the copolymer was found to be 3.53×10 5 g / mol, the molecular weight distribution index (Mw / Mn) was 3.07, the unsaturation degree was 7.1%, among which the content of alloocimene was 3.55%, the content of isobutylene was 96.45%, and no gel component was detected.

[0056] Furthermore, the copolymer was vulcanized by the same vulcanization method as in Example 1, and the hardness was tested. The Shore A hardness of the sulfide was found to be 51.

[0057] Comparative Example 1

[0058] The total molar ratio of the comonomer isobutylene to alloocimene is 95 / 5. At -95°C and under the protection of high-purity nitrogen, with chloroform as the solvent, a chloroform solution of isobutylene (IB) (the mass fraction of IB is 10%) and all the alloocimene are added in sequence in a low-temperature polymerization reactor. After uniform mixing, ethyl aluminum dichloride (the amount of ethyl aluminum dichloride is 1‰ of the molar amount of the comonomer isobutylene) and a dichloromethane initiator solution of hydrogen chloride (the amount of hydrogen chloride is 0.05‰ of the molar amount of the comonomer isobutylene) are added to initiate the copolymerization reaction of the monomers. The total reaction time is 10 minutes. After the polymerization reaction, a white emulsion is obtained. The reaction is terminated with 20ml of anhydrous ethanol. After the polymer product is desolvated, it is placed in a vacuum oven at 40°C and dried for 48 hours to obtain a diblock copolymer with a yield of 53.6%. The fully dried product is tested, and the weight average molecular weight (Mw) of the copolymer is 4.39×10 5 g / mol, the molecular weight distribution index (Mw / Mn) was 2.91, the unsaturation degree was 6.9%, and no gel component was detected.

[0059] Combination Figure 3 and Figure 4 It can be seen that the copolymer of isobutylene and alloocimene is obtained in this example, and the copolymer has an obvious high-temperature melting peak at 80° C., indicating that the copolymer is mainly homopolymerized and is easier to form crystals.

[0060] Furthermore, the copolymer was vulcanized by the same vulcanization method as in Example 1, and the hardness was tested. The Shore D hardness of the sulfide was 56.

[0061] Example 5

[0062] The total molar ratio of the comonomer isobutylene to alloocimene is 95 / 5. At -95°C and under the protection of high-purity nitrogen, with chloroform as the solvent, a chloroform solution of isobutylene (IB) (the mass fraction of IB is 10%), all alloocimenes, and a crosslinker divinylbenzene (the amount of divinylbenzene is 1‰ of the mass fraction of isobutylene) are added in sequence in a low-temperature polymerization reactor. After uniform mixing, ethyl aluminum dichloride (the amount of ethyl aluminum dichloride is 1‰ of the molar amount of the comonomer isobutylene) and a dichloromethane initiator solution of hydrogen chloride (the amount of hydrogen chloride is 0.05‰ of the molar amount of the comonomer isobutylene) are added to initiate the copolymerization reaction of the monomers, and the total reaction time is 10 minutes. After the addition of the crosslinker, the reaction gradually disappears the solution polymerization characteristics over time, and finally presents a slurry polymerization. A white solid product is obtained after the reaction is completed, and the reaction is terminated with 20ml of anhydrous ethanol. After the polymer product is desolventized, it is placed in a 40°C vacuum oven and dried for 48 hours, and the yield of the obtained copolymer is 39.9%. The fully dried product was tested and the weight average molecular weight (Mw) of the copolymer product was found to be 3.62×10 5g / mol, a molecular weight distribution index (Mw / Mn) of 1.61, an unsaturation degree of 13.6%, wherein the content of alloocimene is 6.8%, the content of isobutylene is 93.2%, and the gel content is 3.7%.

[0063] Combination Figure 5 and Figure 6 It can be seen that the copolymer of isobutylene and alloocimene is obtained in this embodiment. After the cross-linking agent is added to the reaction system, there is an obvious high-temperature melting peak at 85°C, indicating that the copolymer is mainly homopolymerized and is easy to produce a crystalline structure. This is because the cross-linking agent pre-cross-links the double bonds in alloocimene in the main chain, so that the linear structure is changed into a cross-linked structure, the alloocimene is arranged more closely, and the crystalline structure is larger, thereby improving the hardness of the copolymer.

[0064] Furthermore, the copolymer was vulcanized by the same vulcanization method as in Example 1, and the hardness was tested. The Shore D hardness of the sulfide was found to be 62.

[0065] Example 6

[0066] The total molar ratio of the comonomer isobutylene to alloocimene is 95 / 5. At -95°C and under the protection of high-purity nitrogen, with chloroform as the solvent, a chloroform solution of isobutylene (IB) (the mass fraction of IB is 10%), all alloocimenes, and a crosslinker divinylbenzene (the amount of divinylbenzene is 2‰ of the mass fraction of isobutylene) are sequentially added to a low-temperature polymerization reactor. After uniform mixing, ethyl aluminum dichloride (the amount of ethyl aluminum dichloride is 1‰ of the molar amount of the comonomer isobutylene) and a dichloromethane initiator solution of hydrogen chloride (the amount of hydrogen chloride is 0.05‰ of the molar amount of the comonomer isobutylene) are added to initiate the monomer copolymerization reaction, and the total reaction time is 10 minutes. After the addition of the crosslinker, the reaction gradually disappears with the passage of time. The solution polymerization characteristics are finally presented as slurry polymerization. A white solid product is obtained after the reaction is completed, and the reaction is terminated with 20ml of anhydrous ethanol. After the polymer product is desolventized, it is placed in a 40°C vacuum oven and dried for 48 hours. The yield of the obtained copolymer is 35.7%. The fully dried product was tested and the weight average molecular weight (Mw) of the copolymer was found to be 3.28×10 5 g / mol, a molecular weight distribution index (Mw / Mn) of 1.84, an unsaturation degree of 15.3%, wherein the content of alloocimene is 7.65%, the content of isobutylene is 92.35%, and the gel content is 5.1%.

[0067] Furthermore, the copolymer was vulcanized by the same vulcanization method as in Example 1, and the hardness was tested. The Shore D hardness of the sulfide was found to be 65.

[0068] Example 7

[0069] The total molar ratio of the comonomer isobutylene to alloocimene is 92 / 8. At -95°C and under the protection of high-purity nitrogen, with chloroform as solvent, a chloroform solution of isobutylene (IB) (the mass fraction of IB is 10%), all alloocimene, and a crosslinker divinylbenzene (the amount of divinylbenzene is 3‰ of the mass fraction of isobutylene) are added in sequence in a low-temperature polymerization reactor. After uniform mixing, ethyl aluminum dichloride (the amount of ethyl aluminum dichloride is 1‰ of the molar amount of the comonomer isobutylene) and a dichloromethane initiator solution of hydrogen chloride (the amount of hydrogen chloride is 0.05‰ of the molar amount of the comonomer isobutylene) are added to initiate the copolymerization reaction of the monomers, and the total reaction time is 10 minutes. After the addition of the crosslinker, the reaction gradually disappears with the passage of time. The solution polymerization characteristics are finally presented as slurry polymerization. A white solid product is obtained after the reaction is completed, and the reaction is terminated with 20ml of anhydrous ethanol. After the polymer product is desolventized, it is placed in a 40°C vacuum oven and dried for 48 hours. The yield of the obtained copolymer is 31.1%. The fully dried product was tested and the weight average molecular weight (Mw) of the copolymer was found to be 2.21×10 5 g / mol, a molecular weight distribution index (Mw / Mn) of 2.78, an unsaturation degree of 21.6%, wherein the content of alloocimene is 10.8%, the content of isobutylene is 89.2%, and the gel content is 6.9%.

[0070] Furthermore, the copolymer was vulcanized by the same vulcanization method as in Example 1, and the hardness was tested. The Shore A hardness of the sulfide was found to be 81.

[0071] Example 8

[0072] The total molar ratio of comonomer isobutylene to alloocimene is 95 / 5. At -95°C and under the protection of high-purity nitrogen, with chloroform as solvent, a chloroform solution of isobutylene (IB) (10% by mass fraction of IB), all alloocimene, and crosslinker 1,5-hexadiene (1,5-hexadiene is 2‰ of the mass fraction of isobutylene) are added in sequence in a low-temperature polymerization reactor. After mixing evenly, a dichloromethane initiator solution of ethylaluminum dichloride (the amount of ethylaluminum dichloride is 1‰ of the molar amount of comonomer isobutylene) and hydrogen chloride (the amount of hydrogen chloride is 0.05‰ of the molar amount of comonomer isobutylene) is added to initiate the copolymerization reaction of the monomers, and the total reaction time is 10 minutes. After the addition of the crosslinker, the reaction gradually loses the characteristics of solution polymerization over time, and finally presents a slurry polymerization. After the reaction, a white solid product was obtained. The reaction was terminated with 20 ml of anhydrous ethanol. After the polymer product was desolventized, it was placed in a vacuum oven at 40°C and dried for 48 hours. The yield of the copolymer was 51.8%. The fully dried product was tested and the weight average molecular weight (Mw) of the copolymer was 2.89×10 5g / mol, a molecular weight distribution index (Mw / Mn) of 2.67, an unsaturation degree of 12.8%, wherein the content of alloocimene is 6.4%, the content of isobutylene is 93.6%, and the gel content is 2.7%.

[0073] Furthermore, the copolymer was vulcanized by the same vulcanization method as in Example 1, and the hardness was tested. The Shore A hardness of the sulfide was found to be 63.

[0074] It can be seen from Examples 1 to 4 and Comparative Example 1 that the polymer obtained by adding isobutylene and alloocimene to the reaction system at one time in Comparative Example 1 has an obvious high-temperature melting peak at 80°C, and the obtained copolymer is easier to crystallize and has a larger hardness value; while when Examples 1 to 4 respectively control the content of alloocimene in the reaction system in batches or dropwise addition, the obtained copolymer has no high-temperature melting peak, is not easy to crystallize, and has a lower hardness.

[0075] It can be seen from Examples 5 to 8 that after adding a cross-linking agent to the reaction system, the obtained copolymer is more likely to produce a crystalline structure. This is because the cross-linking agent pre-cross-links the double bonds in the alloocimene in the main chain, so that the linear structure is changed into a cross-linked structure, the alloocimene is arranged more closely, and the crystalline structure is larger, thereby further improving the hardness of the copolymer; at the same time, the cross-linking agent further increases the unsaturation of the product at the same alloocimene dosage.

[0076] It can be seen that the present invention can regulate the crystallization state of the copolymer and then adjust the hardness range of the copolymer by improving the polymerization process and adding a cross-linking agent, which makes it easy for the copolymer to have a wider hardness range and obtain a copolymer with higher unsaturation while reducing costs.

Claims

1. A method for preparing a copolymer of isobutylene, alloocimene and derivatives thereof, the method comprising the following steps: Adding isobutylene and the first batch of alloocimene and its derivatives into a solvent, then adding an initiator to initiate a polymerization reaction, and then adding the remaining alloocimene and its derivatives in batches or dropwise until the reaction is completed; The amount of the first batch of alloocimene and its derivatives added is 1 to 80% of the total amount of alloocimene and its derivatives; After the initiator is added and reacted for 1 second to 20 minutes, the remaining alloocimene and its derivatives are added in batches or dropwise; The remaining alloocimene and its derivatives are divided into 3 to 8 equal parts and added into the reaction system in batches; The addition time of the remaining alloocimene and its derivatives is controlled to be completed within 1 to 20 minutes; The mass fraction of the isobutylene monomer in the solvent is 5 to 20 wt %; The amount of alloocimene and its derivatives is 2-20% of the total molar content of the monomers; The alloocimene derivative is one of cymene, citronellal, ocimene, myrcene, and 2,3-dimethyl-1,3-butadiene; The initiator comprises a combination of at least one catalyst and at least one proton source; The catalyst is an alkylaluminum halide, an aluminum chloride-derived catalyst or a Lewis acid; The amount of the catalyst used is 0.5 to 5‰ of the molar amount of the isobutylene monomer; The proton source is one or a combination of water, hydrogen chloride, and carboxylic acid; The amount of the proton source is 0.1 to 3‰ of the molar amount of the isobutylene monomer; The solvent is a halogenated hydrocarbon or an isomer of a halogenated hydrocarbon; The polymerization reaction temperature is -120 to -20°C; the polymerization reaction time is 1s to 60min; After the polymerization reaction is completed, the solvent ethanol is added to terminate the reaction, and then the solvent is removed and dried to obtain the copolymer; In the copolymer system, the content of the isobutylene monomer is 50-99%, the content of the alloocimene and its derivatives is 1-50%, and the hardness range of the copolymer is 45-85A; The copolymer has a weight average molecular weight greater than 100 kg / mol, a double bond content greater than 5 mol%, and a gel content less than 8 wt%.

2. The method for preparing the copolymer of isobutylene, alloocimene and derivatives thereof according to claim 1, characterized in that: The copolymer has a weight average molecular weight greater than 150 kg / mol, a double bond content greater than 10 mol%, and a gel content less than 5 wt%.

3. The method for preparing the copolymer of isobutylene, alloocimene and derivatives thereof according to claim 1, characterized in that: The amount of the first batch of alloocimene and its derivatives added is 1 to 30% of the total amount of alloocimene and its derivatives; After the initiator is added and reacted for 1 to 10 minutes, the remaining alloocimene and its derivatives are added in batches or dropwise; The addition time of the remaining alloocimene and its derivatives is controlled to be completed within 1 to 10 minutes.

4. The method for preparing the copolymer of isobutylene, alloocimene and derivatives thereof according to claim 3, characterized in that: The amount of the first batch of alloocimene and its derivatives added is 1 to 20% of the total amount of alloocimene and its derivatives; After the initiator is added and reacted for 1 to 5 minutes, the remaining alloocimene and its derivatives are added in batches or dropwise; The addition time of the remaining alloocimene and its derivatives is controlled to be completed within 2 to 8 minutes.

5. The method for preparing the copolymer of isobutylene, alloocimene and derivatives thereof according to claim 1, characterized in that: The mass fraction of the isobutylene monomer in the solvent is 10 to 15 wt %; The amount of alloocimene and its derivatives is 3-12% of the total molar content of the copolymer monomers.

6. The method for preparing the copolymer of isobutylene, alloocimene and derivatives thereof according to claim 1, characterized in that: The catalyst is one of aluminum trichloride, ethylaluminum dichloride, diethylaluminum chloride, dimethylaluminum chloride and boron trichloride; the amount of the catalyst is 1 to 3‰ of the molar amount of the isobutylene monomer.

7. The method for preparing the copolymer of isobutylene, alloocimene and derivatives thereof according to claim 6, characterized in that: The initiator is a combination of ethylaluminum dichloride and hydrogen chloride.

8. The method for preparing the copolymer of isobutylene, alloocimene and derivatives thereof according to claim 1, characterized in that: The solvent is one or a combination of methyl chloride and dichloromethane.

9. The method for preparing the copolymer of isobutylene, alloocimene and derivatives thereof according to claim 8, characterized in that: The solvent is methyl chloride.

10. The method for preparing the copolymer of isobutylene, alloocimene and derivatives thereof according to claim 1, characterized in that: In the polymerization reaction, the polymerization reaction temperature is -100 to 0°C; and the polymerization reaction time is 1 to 40 minutes.

11. The method for preparing the copolymer of isobutylene, alloocimene and derivatives thereof according to claim 10, characterized in that: In the polymerization reaction, the polymerization reaction temperature is -95 to -10°C; and the polymerization reaction time is 1 to 30 minutes.

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