Pentadiene-based elastomer and preparation method thereof

Abstract

The invention discloses a pentadiene-based elastomer and a preparation method thereof, and belongs to the technical field of high polymer materials. The copolymer is a binary or terpolymer prepared by catalyzing copolymerization of m-pentadiene, conjugated diene, styrene and ethylene with a rare earth catalyst, the content of combined m-pentadiene in the binary or terpolymer is 5%-100% by mole, and the number-average molecular weight is 1 * 10 < 4 >-80 * 10 < 4 >. By changing the rare earth catalyst ligand and the central metal, the cis-1, 4-selectivity is 2%-98%, the trans-1, 4-selectivity is 2%-98%, and the 3, 4-selectivity is 2%-93% when m-pentadiene and conjugated diene are polymerized; when the styrene is polymerized, the polystyrene block can be syndiotactic and random polystyrene. By adopting the rare earth catalyst with high tolerance and selectivity, direct polymerization of crude pentadiene separated from C5 fractions is realized, and controllable copolymerization of pentadiene, ethylene and conjugated olefins including butadiene, isoprene, myrcene and styrene is realized; the pentadiene-based elastomer with controllable composition, sequence structure, spatial configuration and molecular weight is prepared, and the method has important significance on efficient utilization of C5 fractions and development of new materials.

Description

Technical Field

[0001] The invention belongs to the technical field of polymer materials and relates to a piperyl-based elastomer and a preparation method thereof. Background Art

[0002] Isopentadiene (1,3-pentadiene) is one of the main components of petroleum C5 fraction, accounting for about 11.0%, and is a chemical raw material second only to cyclopentadiene and isoprene. Pure isoprene can be separated from the C5 fraction as a polymerization monomer. Currently, the separated pure polymerization-grade isoprene not only achieves selective homopolymerization, but also can be controlled copolymerized with monomers such as butadiene and styrene to produce isoprene rubber, butadiene-pentadiene rubber, integrated rubber and isoprene-styrene block copolymers with excellent performance.

[0003] At present, the separation process of C5 fraction can only separate crude isoprene mainly composed of isoprene. Crude isoprene contains isoprene, alkynes, cyclopentene, cyclopentadiene, alkanes, etc. The crude isoprene with complex components can only be used as a polymerization monomer to prepare petroleum resin, and cannot be used to prepare rubber and elastomeric materials with higher added value. In order to improve the utilization value of isoprene, researchers have studied new materials of isoprene as a polymerization monomer. The anionic initiator butyl lithium can realize the homopolymerization of isoprene and copolymerization with styrene, and obtain polyisopentadiene and isoprene-styrene alternating copolymers with trans-1,4 structural units as the main components. The coordination polymerization catalyst Ziegler-Natta neodymium catalyst realizes the homopolymerization of isoprene and copolymerization with isoprene to obtain polyisopentadiene and isoprene-isoprene copolymer rubber with cis-1,4 structural units as the main components. When butyl lithium and Ziegler-Natta neodymium catalysts catalyze the polymerization of isoprene, harmful impurities such as cyclopentadiene and acetylene in the polymerization monomer must be removed. Coordination polymerization catalysts titanocene and rare earth ocene catalysts can also achieve isoprene polymerization, and the ligand structure can be adjusted to obtain polyisopentadiene with a content of cis-1,4-structure, cis-1,2-structure, and trans-1,4-structure units up to 90%. However, the catalytic activity of titanium catalysts is low. Even if the catalyst with the highest activity catalyzes the polymerization of isoprene for 4 hours, the yield of polyisopentadiene is only 66%. Both types of metallocene catalysts require the use of pure isoprene as the polymerization monomer.

[0004] So far, the isoprene monomer used for polymerization must be pure or free of harmful impurities such as cyclopentadiene and acetylenes, and there are few studies on the copolymerization of isoprene with other olefins. Currently, only isoprene-isoprene and isoprene-butadiene copolymer rubbers with cis-1,4 structural units as the main components, and isoprene-styrene alternating copolymers with trans-1,4 structural units as the main components can be obtained. Summary of the invention

[0005] In view of the problems existing in the prior art, the present invention provides a type of piperylene-based elastomer and a preparation method thereof. The present invention realizes the controllable copolymerization of crude piperylene, intermediate piperylene and ethylene, conjugated olefins including butadiene, isoprene, and myrcene styrene by designing and synthesizing a rare earth catalyst, using crude piperylene separated from a carbon five fraction as a polymerization monomer, and prepares a piperylene-based elastomer with controllable composition, sequence structure, stereo configuration, and molecular weight. The method does not require purification of crude piperylene, greatly reduces the energy consumption of preparing piperylene-based rubber, which is of great significance to the high added value effective utilization of carbon five fractions and the development of new materials.

[0006] In order to achieve the above object, the technical solution adopted by the present invention is:

[0007] A piperyl-based elastomer, which is prepared by polymerization of piperyl, and is a binary or ternary copolymer prepared by copolymerization of piperyl with conjugated olefins and ethylene using a rare earth catalyst; wherein the combined piperyl content in the binary or ternary copolymer is 5% to 100% by mole percentage, and the number average molecular weight is 1×10 4 ~80×10 4 .

[0008] Furthermore, the piperylene is selected from a mixture mainly composed of piperylene separated from a C5 fraction. The conjugated olefin is selected from one or a mixture of styrene, butadiene, isoprene and myrcene.

[0009] Furthermore, the rare earth catalyst comprises a main catalyst and a co-catalyst. The main catalyst is a rare earth metallocene compound, and its molecular formula is CpLnR2X n , wherein Cp is selected from cyclopentadienyl, substituted cyclopentadienyl, indenyl, substituted indenyl, fluorenyl or substituted fluorenyl; Ln is selected from rare earth metals; R is an alkyl group directly connected to the rare earth metal, selected from CH2SiMe3, CH2C6H4NMe2-o, CH2Ph, CH2CH=CH2, 1,3-C3H4(Me), 1,3-C3H3(SiMe3)2, CH(SiMe3)2, CH3, CH2CH3, i-Pr, t-Bu; X is a coordination group on the rare earth metal, selected from Lewis bases containing O, N, P, S heteroatoms, and n is the number of Lewis bases, selected from 0 or 1. The co-catalyst is an organic boron reagent, or a mixture of an alkyl aluminum and an organic boron reagent. The organoboron reagent is selected from [Ph3C][B(C6F5)4], [PhMe2NH][B(C6F5)4], [HNMe(C 18 H 37)2][B(C6F5)4], B(C6F5)3 or a mixture thereof. The alkyl aluminum reagent is selected from trimethyl aluminum, triethyl aluminum, triisobutyl aluminum, methyl aluminoxane or a mixture thereof.

[0010] A method for preparing a piperyl-based elastomer comprises the following steps:

[0011] Under the protection of inert gas nitrogen or argon, add organic solvent and rare earth catalyst according to the proportion to a dry and deoxygenated polymerization reactor, stir and control the temperature at -20°C to 80°C, mix or add the polymerization monomers into the reaction system in steps, react for 5 minutes to 4 hours, obtain the corresponding random, multi-block or block copolymers, terminate, precipitate, wash and dry the polymers by conventional post-treatment methods to obtain copolymers. The polymerization monomers are a mixture of piperylene, conjugated olefins and ethylene, or a mixture of piperylene and conjugated olefins, or a mixture of piperylene and ethylene.

[0012] Furthermore, in the rare earth catalyst, when the co-catalyst is an organic boron reagent, the molar ratio of the organic boron reagent to the rare earth metallocene compound is 1; when the co-catalyst is an alkyl aluminum, the molar ratio of the alkyl aluminum to the rare earth metallocene compound is 0-500.

[0013] Furthermore, the molar ratio of the polymerization monomer to the rare earth metallocene compound is 1000-500000.

[0014] Furthermore, the organic solvent is selected from one or a mixture of two or more of n-hexane, cyclohexane, n-heptane, benzene, toluene, xylene, chlorobenzene, dichlorobenzene and trichlorobenzene.

[0015] Furthermore, in the preparation method, when the polymerization monomer is piperylene, butadiene, isoprene, or myrcene, by controlling the ligand structure and central metal of the rare earth catalyst, the cis-1,4-selectivity of the polymerization monomer is 2%-98%, the trans-1,4-selectivity of piperylene is 2%-98%, and the myrcene and isoprene 3,4-selectivity is 2%-93%. When the polymerization monomer is styrene, by controlling the ligand structure and central metal of the rare earth catalyst, the polystyrene block can be syndiotactic or atactic polystyrene during polymerization.

[0016] The piperyl-based elastomer and the preparation method thereof provided by the present invention have the following beneficial effects:

[0017] The invention realizes direct polymerization of crude isopentadiene separated from a C5 fraction by adopting a designed synthetic rare earth catalyst. Since the catalyst is tolerant to substances such as cyclopentadiene and acetylenes in the crude isopentadiene and is only active in polymerization of the intermediate isopentadiene in the crude isopentadiene but inactive in polymerization of the monoolefins therein, it is unnecessary to carry out time-consuming and energy-consuming separation and purification of the crude isopentadiene, and controllable copolymerization of the intermediate isopentadiene in the crude isopentadiene with ethylene and conjugated olefins (wherein the conjugated olefins include butadiene, isoprene and myrcene styrene) is realized, and an isopentadiene-based elastomer with controllable composition, sequence structure, stereo configuration and molecular weight is prepared, which is of great significance to the high added value effective utilization of the C5 fraction and the development of new materials. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 This is the NMR spectrum of polyisoprene of Comparative Example 1;

[0019] Figure 2 is the DSC curve of polyisoprene of Comparative Example 1;

[0020] Figure 3 This is the NMR spectrum of polyisoprene of Example 5;

[0021] Figure 4 is the DSC curve of polyisoprene of Example 5;

[0022] Figure 5 This is the NMR spectrum of the piperylene-isoprene copolymer of Example 6;

[0023] Figure 6 is the DSC curve of piperylene-isoprene copolymer of Example 6;

[0024] Figure 7 This is the NMR spectrum of the piperylene-styrene multi-block copolymer of Example 8;

[0025] Figure 8 is the DSC curve of the piperylene and styrene multi-block copolymer of Example 8;

[0026] Fig. 9 This is the NMR spectrum of the random copolymer of piperylene and styrene of Example 9;

[0027] Fig.10 This is the DSC curve of the random copolymer of piperylene and styrene in Example 9. DETAILED DESCRIPTION

[0028] The present invention is further described below in conjunction with specific embodiments.

[0029] The present invention provides the following examples as further illustrations, but they are not intended to limit the scope of protection of the present invention.1 H-, 13 C-NMR) was used to detect the content and structure (molar percentage, %) of the obtained piperylene-based elastomer component, gel permeation chromatography (GPC) was used to determine the molecular weight and molecular weight distribution index (ratio of weight average molecular weight to number average molecular weight) of the piperylene-based elastomer, and differential scanning calorimetry (DSC) was used to determine the glass transition temperature (T g ) and melting point (T m ).

[0030] Examples 1 to 4 are preparations of rare earth catalysts:

[0031] Example 1, Preparation of (C5H4Me)Y(CH2SiMe3)2(NHC)

[0032] In the glove box, weigh 10mmol YCl3 and put it into a Schlenk bottle with a magnetic stirrer, add 20mL of tetrahydrofuran, seal it, take out the glove box, and stir at 40℃ for 12h. Take the activated YCl3(THF)3 white suspension into the glove box, weigh 30mmol trimethylsilylmethyllithium LiCH2SiMe3, add 40mL of tetrahydrofuran to dissolve it, and add it dropwise to the activated YCl3(THF)3 white suspension. After reacting for 30min, vacuum remove the solvent tetrahydrofuran, add 20mL of n-hexane to extract, and put the extract in the refrigerator to freeze out the by-products, filter it while it is cold, and drain the solvent n-hexane to obtain 4.546g of white solid Y(CH2SiMe3)3(THF)2. In the glove box, weigh 7.25mmol Y(CH2SiMe3)3(THF)2 and put it into a round-bottom flask with a magnetic stirrer, add 10mL of n-hexane solvent to dissolve it. Weigh 7.25mmol of methylcyclopentadiene C5H5Me, dissolve it in 1.0mL of n-hexane, and add it dropwise to the reaction bottle at room temperature. After stirring at room temperature for 2h, the reaction was concentrated under reduced pressure to about 1mL, placed in a -30℃ refrigerator overnight, and recrystallized to obtain 3.772g of crystals (C5H4Me)Y(CH2SiMe3)2THF, with a yield of 80%.

[0033] Embodiment 2, {C 13 Preparation of H9(SiMe3)}Lu(CH2SiMe3)2(NHC)

[0034] In the glove box, weigh 10mmol LuCl3 and put it into a Schlenk bottle with a magnetic stirrer, add 20mL of tetrahydrofuran, seal it, take out the glove box, and stir at 40℃ for 12h. Take the activated LuCl3(THF)3 white suspension into the glove box, weigh 30mmol trimethylsilylmethyllithium LiCH2SiMe3, add 40mL of tetrahydrofuran to dissolve it, and add it dropwise to the activated LuCl3(THF)3 white suspension. After reacting for 30min, vacuum remove the solvent tetrahydrofuran, add 20ml of n-hexane to extract, and put the extract in the refrigerator to freeze out the by-products, filter it while it is cold, and drain the solvent n-hexane to obtain 4.546g of white solid Lu(CH2SiMe3)3(THF)2. In the glove box, weigh 7.25mmol Lu(CH2SiMe3)3(THF)2 and put it into a round-bottom flask with a magnetic stirrer, add 10mL of n-hexane solvent to dissolve it. Weigh 7.25mmol of substituted fluorene C 13 H 10 (SiMe3) was dissolved in 1.0 mL of n-hexane and then added dropwise to the reaction flask at room temperature. The reaction was stirred at room temperature for 2 h, concentrated under reduced pressure to about 1 mL, and placed in a -30°C refrigerator overnight. Recrystallization gave 3.772 g of crystals {C 13 H9(SiMe3)}Lu(CH2SiMe3)2THF. In a glove box, weigh 2.0mmol of 1,3-diisopropylimidazole hydrochloride into an eggplant-shaped bottle, add 10mL of toluene to make a suspension, add 2.0mmol of trimethylsilylmethyl lithium in 6mL of toluene solution dropwise under stirring, and stir at room temperature overnight. Add the mixture dropwise into 2.0mmol{C 13 H9(SiMe3)}Lu(CH2SiMe3)2THF was added to 10 mL of toluene solution and stirred at room temperature for 1 h. After the reaction was completed, the system was filtered, and the filtrate was concentrated and recrystallized at -30°C to obtain 1.035 g of {C 13 H9(SiMe3)}Lu(CH2SiMe3)2(NHC), yield 82%.

[0035] Example 3, Preparation of (C9H7)Sc(CH2C6H4NMe2-o)2

[0036] In a glove box, add 100.0mmol N,N-dimethyl-o-toluidine to 40mL ether solution and start stirring, then add 100.0mmol n-butyl lithium solution, stir at room temperature and react for 3 days. After the reaction is completed, remove the ether solvent in vacuo, wash the residual solid with n-hexane and drain to obtain 12.549g of light yellow solid LiCH2C6H4NMe2-o. Weigh 10.0mmol ScCl3 powder in a glove box and add it to 8mL tetrahydrofuran. Weigh 30.0mmol solid LiCH2C6H4NMe2-o and dissolve it in 14mL tetrahydrofuran. After it is completely dissolved, add it dropwise to the tetrahydrofuran suspension of ScCl3 and react for 0.5h. After the reaction is completed, remove the tetrahydrofuran solvent in vacuo, add 28mL toluene to the residual solid to dissolve, filter, and vacuum dry the filtrate to remove toluene to obtain 4.301g of khaki powder Sc(CH2C6H4NMe2-o)3. In a glove box, weigh 4.0mmol Sc(CH2C6H4NMe2-o)3 and put it into a Schlenk bottle with a magnetic stirrer, and add 12mL tetrahydrofuran solvent to dissolve it. Weigh 4.8mmol indene, dissolve it with 6mL tetrahydrofuran, and add it to the Schlenk bottle at room temperature. After sealing the Schlenk bottle, take it out of the glove box and put it in an oil bath, heat it to 40℃ and stir it for 1h, take it back into the glove box, remove the solvent in vacuo, extract the residual solid with toluene, concentrate it and put it in a -30℃ refrigerator overnight, and recrystallize it to obtain 1.271g yellow crystal (C9H7)Sc(CH2C6H4NMe2-o)2, with a yield of 84%.

[0037] Example 4, Preparation of (C5H5)Nd(CH2C6H4NMe2-o)2

[0038] In a glove box, weigh 10mmol NdCl3 powder and add it to 8mL tetrahydrofuran. Weigh 30mmol solid LiCH2C6H4NMe2-o and dissolve it in 14mL tetrahydrofuran. After it is completely dissolved, add it dropwise to the tetrahydrofuran suspension of NdCl3 and stir at room temperature at 25℃ for 12h. After the reaction is completed, remove the tetrahydrofuran solvent in vacuo, add 30mL toluene to the residual solid to dissolve, filter, and vacuum dry the filtrate to remove toluene to obtain 4.926g earthy brown powder Nd(CH2C6H4NMe2-o)3. In a glove box, weigh 4mmol Nd(CH2C6H4NMe2-o)3 and put it into an eggplant-shaped bottle with a magnetic stirrer, and add 12mL tetrahydrofuran solvent to dissolve it. Weigh 4.80 mmol of cyclopentadiene, dissolve it in 6 mL of tetrahydrofuran, add it to an eggplant-shaped flask, stir and react at room temperature 25°C for 12 hours, remove the solvent in vacuo, wash the remaining solid with n-hexane, filter, and dry the residue in vacuo to remove n-hexane to obtain 1.849 g of earthy brown powder (C5H5)Nd(CH2C6H4NMe2-o)2, with a yield of 80%.

[0039] Example 5: Preparation of polyisoprene by homopolymerization of crude isoprene

[0040] In a glove box, add 10 μmol of the catalyst (C5H4Me)Y(CH2SiMe3)2(NHC) prepared in Example 1 to an eggplant-shaped bottle, dissolve it in 2 mL of toluene, and then add an equimolar amount of [Ph3C][B(C6F5)4]2 mL toluene solution under stirring, and then add 1.5307 g of crude isopentadiene, which is obtained by separation of C5 fraction and consists of isopentadiene (44.5 wt%), cyclopentene (17.8 wt%), cyclopentadiene (0.5 wt%), dicyclopentadiene (0.2 wt%), alkynes and alkanes and other components (37 wt%). Stir the reaction at 25°C for 2 min, add methanol to terminate the reaction, wash the polymer with methanol, and dry it in vacuo to obtain 0.6800 g of the polymer product.

[0041] The results of polymer structure and property analysis are as follows: the NMR spectrum of the polymerization product is consistent with that of Example 5, indicating that only piperylene in the crude piperylene is polymerized, and other components do not participate in the polymerization. The polymerization product is polypiperylene, and the ratio of cis-1,4 / trans-1,4 / cis-1,2 / trans-1,2 structural units is 2 / 94 / 1 / 3; the polymerization product T g The temperature is -36℃; the number average molecular weight of the polymerized product is 7.3×10 4 , molecular weight distribution index (M w / M n ) is 1.75, and other components in crude piperylene do not affect the molecular weight of polypiperylene.

[0042] Example 6, Preparation of random copolymer of piperylene and isoprene

[0043] In a glove box, 10 μmol of the catalyst (C9H7)Sc(CH2C6H4NMe2-o)2 prepared in Example 3 was added to an eggplant-shaped bottle, dissolved in 8 mL of n-hexane, and then an equal molar amount of [HNMe(C 18 H 37 )2][B(C6F5)4], add 80mL of n-hexane, then add 4mmol of triisobutylaluminum and a mixture of 187.5g of C5 fraction, the C5 fraction is composed of isoprene (10.9wt%), isoprene (25.8wt%), cyclopentadiene (9.9wt%), monoolefins (23.4wt%), alkanes and alkynes and other components (30wt%). Stir the reaction at 25℃ for 2min, add methanol to terminate the reaction, wash the polymer with methanol, and dry under vacuum to obtain 68g of polymer product.

[0044] The results of polymer structure and performance analysis are as follows: NMR spectrum analysis of the polymerization product shows that the copolymerization of isoprene and isoprene in the C5 fraction forms a random isoprene-isoprene copolymer, with a molar content of 27% for isoprene and 73% for isoprene. The ratio of cis-1,4 / trans-1,4 / cis-1,2 / trans-1,2 structural units of polyisoprene is 80 / 3 / 0 / 17, and the ratio of cis-1,4 / trans-1,4 / 3,4- / 1,2-structural units of polyisoprene is 97 / 0 / 3 / 0. The number average molecular weight of the random isoprene-isoprene copolymer is 73×10 4 , molecular weight distribution index (M w / M n ) is 2.25, the glass transition temperature T g It is -55℃.

[0045] Example 7, Preparation of Block Copolymer of Piperylene and Myrcene

[0046] In a glove box, 10 μmol of the catalyst prepared in Example 2 was added to the eggplant-shaped bottle. 13 H9(SiMe3)}Lu(CH2SiMe3)2(NHC) was dissolved in 8 mL of chlorobenzene and an equal molar amount of [PhMe2NH][B(C6F5)4]8 mL of chlorobenzene solution was added under stirring, and then a mixture of 15 μmol of triethylaluminum and 7.6539 g of crude isopentylene (containing 50 mmol of isopentylene) was added, and the mixture was stirred and polymerized at 25°C for 2 h. A mixture of 15 μmol of triethylaluminum and 50 mmol of myrcene was added, and the reaction was stirred at 25°C for 2 h. Methanol was added to terminate the reaction, and the polymer was washed with methanol and dried in vacuo to obtain 10.2177 g of a polymerization product.

[0047] The results of polymer structure and property analysis are as follows: NMR spectrum analysis of the polymer product shows that the polymer product is a piperylene-myrcene block copolymer, with a piperylene content of 50% and a myrcene content of 50% in mole percentage, a cis-1,4 / trans-1,4 / cis-1,2 / trans-1,2 structural unit ratio of polypiperylene of 30 / 54 / 1 / 15, and a myrcene cis-1,4 / trans-1,4 / 3,4- / 1,2-structural unit ratio of 6 / 4 / 90 / 0; the number average molecular weight of the piperylene-myrcene block copolymer is 33×10 4 , molecular weight distribution index (M w / M n ) is 2.25, T g It is -49℃.

[0048] Example 8, Preparation of a multi-block copolymer of piperylene and styrene

[0049] In a glove box, 10 μmol of the catalyst (C9H7)Sc(CH2C6H4NMe2-o)2 prepared in the above Example 3 was added to an eggplant-shaped bottle, dissolved in 8 mL of toluene, and then an equimolar amount of [Ph3C][B(C6F5)4]8 mL toluene solution was added with stirring. Then, 1 mmol of triethylaluminum, 7.6539 g of crude isopentylene (containing 50 mmol of isopentylene) and 50 mmol of styrene were added as a mixture at room temperature. The mixture was stirred and polymerized at 25°C for 3 h. Methanol was added to terminate the reaction, and the polymer was washed with methanol and dried in vacuo to obtain 8.6135 g of a polymer product.

[0050] The results of polymer structure and performance analysis are as follows: NMR spectrum analysis of the polymer product shows that the polymer product is a piperylene-styrene multi-block copolymer, with a piperylene content of 45% and a styrene content of 55% in mole percentage, a polypiperylene cis-1,4 / trans-1,4 / cis-1,2 / trans-1,2 structural unit ratio of 85 / 3 / 0 / 11, and a styrene block of syndiotactic structure; the number average molecular weight of the piperylene-styrene multi-block copolymer is 23×10 4 , molecular weight distribution index (M w / M n ) is 2.01, T g -49℃, T m It is 259℃.

[0051] Example 9, Preparation of random copolymer of piperylene and styrene

[0052] In a glove box, 10 μmol of the catalyst prepared in Example 4 (C 13H9)Nd(CH2C6H4NMe2-o)2 was dissolved in 4 mL of toluene, and then an equimolar amount of [Ph3C][B(C6F5)4]4 mL toluene solution was added under stirring, and the temperature was raised to 70°C, and then a mixture of 0.5 mmol of trimethylaluminum, 3.0616 g of crude isobutylene (containing 20 mmol of isobutylene) and 20 mmol of styrene was added, and the mixture was stirred at 70°C for 2 h. Methanol was added to terminate the reaction, and the polymer was washed with methanol and dried in vacuo to obtain 3.4454 g of a polymer product.

[0053] The results of the structure and performance analysis of the polymerization product are as follows: The NMR spectrum analysis of the polymerization product shows that the polymerization product is a piperylene-styrene random copolymer, with a piperylene content of 41% and a styrene content of 59% in mole percentage, and a 1,4 / 1,2 structural unit ratio of polypiperylene of 88 / 12; the number average molecular weight of the piperylene-styrene random copolymer is 13×10 4 , molecular weight distribution index (M w / M n ) is 1.96, T g is 15℃.

[0054] Example 10, Preparation of piperylene-ethylene copolymer

[0055] In the glove box, 3.0616 g of crude piperylene (containing 20 mmol of piperylene) in 10 mL of toluene solution was added to a two-necked bottle. The two-necked bottle was sealed with a glass joint and transferred from the glove box to an ethylene fume hood. The Schlenk and ethylene branches were connected. After nitrogen replacement several times, 1.01×10 5 Pa pressure ethylene was introduced into the two-necked bottle, mixed and stirred for 2 minutes, and then 10 μmol of the catalyst (C9H7)Sc(CH2C6H4NMe2-o)2 prepared in Example 3 and 4 mL of toluene solution of [Ph3C][B(C6F5)4] in an equal molar amount were quickly added into the two-necked bottle through a sealed needle, and the polymerization reaction was carried out at 25°C for 10 minutes. Methanol was added to terminate the reaction, and the polymer was washed with methanol and dried in vacuo to obtain 2.7 g of a polymer product.

[0056] The results of the structure and performance analysis of the polymerization product are as follows: The NMR spectrum analysis of the polymerization product shows that the polymerization product is a piperylene-ethylene copolymer, with a piperylene content of 12% and an ethylene content of 88% in mole percentage, a ratio of cis-1,4 / trans-1,4 / cis-1,2 / trans-1,2 structural units of polypiperylene of 88 / 2 / 0 / 10, and the piperylene structural unit is isolated and inserted into the polyethylene block; the number average molecular weight of the piperylene-ethylene copolymer is 9.8×10 4 , molecular weight distribution index (M w / M n ) is 1.86, Tg -49℃, T m is 130℃.

[0057] Example 11 Preparation of a terpolymer of isopentylene, styrene and ethylene

[0058] In the glove box, 10 mmol styrene, 1.5308 g crude isopentylene (containing 10 mmol isopentylene), and 20 mL toluene solution were added to a two-necked bottle. The two-necked bottle was sealed with a glass joint and transferred from the glove box to an ethylene fume hood. The two-necked bottle was connected to the Schlenk and ethylene branches. After nitrogen replacement several times, 1.01×10 5 Pa pressure of ethylene was passed into the two-necked bottle, mixed and stirred for 5 minutes, and then 10 μmol of the catalyst prepared in Example 2 was added. 13 H9(SiMe3)}Lu(CH2SiMe3)2(NHC) and an equimolar amount of [Ph3C][B(C6F5)4]4mL toluene solution were quickly added to a two-necked bottle through a sealed needle and polymerized at 50°C for 10 minutes. Methanol was added to terminate the reaction, and the polymer was washed with methanol and dried in vacuo to obtain 1.9g of polymer product.

[0059] The results of the structure and performance analysis of the polymerization product are as follows: The NMR spectrum analysis of the polymerization product shows that the polymerization product is a piperylene-styrene-ethylene terpolymer, with a piperylene content of 18%, a styrene content of 22%, and an ethylene content of 60% in mole percentage, and a polypiperylene cis-1,4 / trans-1,4 / cis-1,2 / trans-1,2 structural unit ratio of 35 / 52 / 1 / 12; the number average molecular weight of the piperylene-styrene-ethylene copolymer is 19.3×10 4 , molecular weight distribution index (M w / M n ) is 1.56, T g -30℃, T m is 130℃.

[0060] Comparative Example 1: Preparation of polyisoprene from pure isoprene

[0061] In a glove box, 10 μmol of the catalyst (C5H4Me)Y(CH2SiMe3)2(NHC) prepared in Example 1 was added to a 100 mL eggplant-shaped bottle, dissolved in 2 mL toluene, and then an equimolar amount of [Ph3C][B(C6F5)4]2 mL toluene solution was added under stirring, and then 10 mmol of pure isoprene was added, stirred at 25°C for 2 min, methanol was added to terminate the reaction, and the polymer was washed with methanol and vacuum dried to obtain isoprene homopolymer with a yield of 98%. The results of the structure and performance analysis of the obtained polyisopentadiene are as follows: the number average molecular weight is 7.6×10 4, molecular weight distribution index (M w / M n ) is 1.48, T g The temperature is -36°C, and the ratio of cis-1,4 / trans-1,4 / cis-1,2 / trans-1,2 structural units is 2 / 94 / 1 / 3. Compared with Example 5, it can be seen that the polymerization of pure piperylene and crude piperylene catalyzed by the metallocene catalyst reported in this patent have exactly the same effect, and the other components in crude piperylene except piperylene do not affect the catalytic activity and catalytic selectivity, and the other components except piperylene can be used as polymerization solvents.

[0062] Comparative Example 2

[0063] In a glove box, 9 μmol of catalyst Nd(P 204 )3, dissolved in 2mL of n-hexane, added 45μmol of triisobutylaluminum under stirring, sealed the ampoule with a latex tube and a glass plug, and took it outside the glove box to a 50℃ oil bath for reaction for 15min. Use a sealing needle to take out 27μmol of diethylaluminum chloride from the glove box, add it to the ampoule, and continue to react in a 50℃ oil bath for 15min to obtain the aged Ziegler-Natta rare earth catalyst Nd(P 204 )3 / triisobutylaluminum / diethylaluminum chloride. 1.5307g of crude isoprene was added to the catalyst, and the reaction was stirred at 60°C for 12h, and no polymerization product was generated. The Ziegler-Natta rare earth catalyst that can catalyze the efficient polymerization of pure butadiene and isoprene cannot catalyze the polymerization of crude isoprene. Compared with Example 5, it can be seen that cyclopentadiene and the like in crude isoprene can poison the traditional Ziegler-Natta rare earth catalyst and cannot catalyze the polymerization of crude isoprene, while the metallocene catalyst reported in this patent is completely unaffected by it.

[0064] The above-described embodiments merely express the implementation methods of the present invention, but they cannot be understood as limiting the scope of the patent of the present invention. It should be pointed out that for those skilled in the art, several modifications and improvements can be made without departing from the concept of the present invention, which all belong to the protection scope of the present invention.

Claims

1. A piperyl-based elastomer, characterized in that: The piperyl-based elastomer is prepared by polymerization of piperyl, and is a type of binary or ternary copolymer prepared by copolymerization of piperyl with conjugated olefins and ethylene using a rare earth catalyst; wherein the content of combined piperyl in the binary or ternary copolymer is 5%-100% by mole percentage, and the number average molecular weight is 1×10 4 ~80×10 4 .

2. The piperyl-based elastomer according to claim 1, characterized in that: The piperylene is selected from a mixture mainly composed of piperylene separated from the C5 fraction.

3. The piperyl-based elastomer according to claim 1, characterized in that: The conjugated olefin is selected from styrene, butadiene, isoprene, myrcene or a mixture of two thereof.

4. The piperyl-based elastomer according to claim 1, characterized in that: The rare earth catalyst comprises a main catalyst and a co-catalyst, wherein the main catalyst is a rare earth metallocene compound, and the co-catalyst is an organic boron reagent, or a mixture of alkyl aluminum and an organic boron reagent.

5. The piperyl-based elastomer according to claim 4, characterized in that: In the rare earth catalyst: The molecular formula of the rare earth metallocene compound is CpLnR2X n , wherein Cp is selected from cyclopentadienyl, substituted cyclopentadienyl, indenyl, substituted indenyl, fluorenyl or substituted fluorenyl; Ln is selected from rare earth metals; R is an alkyl group directly connected to the rare earth metal, selected from CH2SiMe3, CH2C6H4NMe2-o, CH2Ph, CH2CH=CH2, 1,3-C3H4(Me), 1,3-C3H3(SiMe3)2, CH(SiMe3)2, CH3, CH2CH3, i-Pr, t-Bu; X is a coordination group on the rare earth metal, selected from Lewis bases containing O, N, P, S heteroatoms, and n is the number of Lewis bases, selected from 0 or 1; The organoboron reagent is selected from [Ph3C][B(C6F5)4], [PhMe2NH][B(C6F5)4], [HNMe(C 18 H 37 )2][B(C6F5)4], B(C6F5)3 or a mixture of any of them; The alkyl aluminum reagent is selected from one or a mixture of trimethyl aluminum, triethyl aluminum, triisobutyl aluminum, and methyl aluminoxane.

6. The method for preparing a piperyl elastomer according to any one of claims 1 to 5, characterized in that: The following steps are involved: Under the protection of inert gas, an organic solvent and a rare earth catalyst are added to a polymerization reactor according to a proportion, the temperature is controlled at -20°C to 80°C by stirring, the polymerization monomers are mixed or added stepwise to the reaction system, and the reaction is carried out for 5 minutes to 4 hours to obtain corresponding random, multi-block or block copolymers, and the polymer is terminated, precipitated, washed and dried by a traditional post-treatment method to obtain a copolymer; the polymerization monomers are a mixture of piperylene, a conjugated olefin and ethylene, or a mixture of piperylene and a conjugated olefin, or a mixture of piperylene and ethylene.

7. The method for preparing a piperyl-based elastomer according to claim 6, characterized in that: In the rare earth catalyst, when the cocatalyst is an organic boron reagent, the molar ratio of the organic boron reagent to the rare earth metallocene compound is 1; when the cocatalyst is an alkyl aluminum, the molar ratio of the alkyl aluminum to the rare earth metallocene compound is 0-500.

8. The method for preparing a piperyl-based elastomer according to claim 6, characterized in that: The molar ratio of the polymerization monomer to the rare earth metallocene compound is 1000-500000.

9. The method for preparing a piperyl-based elastomer according to claim 6, characterized in that The organic solvent is selected from one or a mixture of two or more of n-hexane, cyclohexane, n-heptane, benzene, toluene, xylene, chlorobenzene, dichlorobenzene and trichlorobenzene.

10. The method for preparing a piperyl-based elastomer according to claim 6, characterized in that: The preparation method, when the polymerization monomer is piperylene, butadiene, isoprene, or myrcene, controls the ligand structure and central metal of the rare earth catalyst, so that during polymerization of the polymerization monomer, the cis-1,4-selectivity is 2%-98%, the trans-1,4-selectivity of piperylene is 2%-98%, and the myrcene and isoprene 3,4-selectivity is 2%-93%; when the polymerization monomer is styrene, controls the ligand structure and central metal of the rare earth catalyst, so that during polymerization, the polystyrene block can be syndiotactic or atactic polystyrene.

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