CN116003660A

CN116003660A - Linear poly-1, 3-pentadiene elastomer with high trans-1, 4-structure content and preparation method and application thereof

Info

Publication number: CN116003660A
Application number: CN202111235804.6A
Authority: CN
Inventors: 呼振鹏; 邓皓云; 徐伟箭; 张�杰; 吕万树; 王雪; 杨智雄; 赵姜维
Original assignee: Sinopec Beijing Research Institute of Chemical Industry; China Petroleum and Chemical Corp; Hunan University
Current assignee: Sinopec Beijing Research Institute of Chemical Industry; China Petroleum and Chemical Corp; Hunan University
Priority date: 2021-10-22
Filing date: 2021-10-22
Publication date: 2023-04-25

Abstract

The invention relates to the technical field of functional polymers, and discloses a linear poly-1, 3-pentadiene elastomer with high trans-1, 4-structure content, a preparation method and application thereof. The poly-1, 3-pentadiene elastomer comprises 50 to 95 mole% of trans-1, 4-structure and the content of 1,4-4,1 head-to-tail linkages in the microscopic sequence distribution of the poly-1, 3-pentadiene elastomer is 30 to 80 mole%. The preparation method is simple, and the microstructure can be regulated and controlled efficiently; in the prepared poly (1, 3-pentadiene) elastomer, the proportion of trans-1, 4-structure is very high, the sequence of the polymer is highly regular, the linear degree of the polymer is good, and the 1,4-4,1 head-tail linkage mode is dominant.

Description

Linear poly-1, 3-pentadiene elastomer with high trans-1, 4-structure content and preparation method and application thereof

Technical Field

The invention relates to the technical field of functional polymers, in particular to a linear poly-1, 3-pentadiene elastomer with high trans-1, 4-structure content, a preparation method and application thereof.

Background

With the high-speed development of aerospace and automobile industries, development of novel rubber with special purposes, energy conservation and environmental protection becomes important. The high trans-1, 4-structure polydiene rubber has low heat generation, high fatigue resistance and wear resistance, and simultaneously effectively balances the rolling resistance of the tire, thereby being an ideal rubber formulation for developing high-performance energy-saving tires.

The current high-reflection polydiolefins such as high-trans polybutadiene (HTBD), high-Trans Polyisoprene (TPI) and high-trans poly Bd-Ip are prepared by using a Z-N catalyst or lithium polymerization. The polymer obtained by the coordination system catalytic system has very high trans-1, 4-structure, slightly poor control capability of a lithium system structure, strong designability of a molecular structure, narrower molecular weight distribution and advantages in Mooney viscosity and cold fluidity. TPI and HTBD prepared by the Z-N catalyst have trans-1, 4-structure content up to 99%, the polymer presents crystallinity due to excessively high trans-structure content, the polymer is hard plastic at normal temperature, the sulfur content used for vulcanization and cross-linking is large, or the polymer is co-vulcanized with other rubber types, and the polymer is not easy to process due to excessively high melting temperature; the introduction of a small amount of Ip adopts lithium series copolymerization, so that the regularity of chain segments can be effectively reduced, the complete crystallization process is avoided, but the side propenyl structure content of Ip cannot be effectively controlled, and the elasticity of the polymer can be reduced.

1, 3-pentadiene is an important conjugated diene derived from a C5 fraction which is an ethylene cracking byproduct, and the industrialization of an elastomer material is not realized at present, and is generally used for producing C5 petroleum resin. The product route and the process method of the lithium elastomer process are suitable for the polymerization of the 1, 3-pentadiene, and the chemical stereospecific formed by different addition modes and the stereoisomer of asymmetric carbon atoms show different mechanical properties from polybutadiene rubber and isoprene rubber. The research shows that the addition mode of the 1, 3-pentadiene is mainly 1, 4-and 4, 1-addition, continuous tail trans-4, 1-and head trans-1, 4-structures are easy to form in chain segments under a specific catalytic system, the polymer chain is highly regular, the obtained elastomer can be stretched and crystallized, the heat generation, wet skid resistance and wear resistance are more outstanding, and the related research reports are few at present.

The solid-state company discloses that Sodium Dodecyl Benzene Sulfonate (SDBS) is adopted to prepare SIR rubber with high trans-1, 4-structure content, the combination amount of St is from 10% to 40%, and the SDBS plays a role of randomizing agent besides serving as a trans-1, 4-structure regulator of Ip. The copolymer obtained by the method has wide molecular weight distribution, outstanding raw rubber performance and adhesiveness, and can be used for tread rubber of high-performance pneumatic tires. However, this process does not involve 1, 3-pentadiene and the overall trans 1, 4-structure is still not sufficiently high (Adel f.halasa, chad Jusinas, wen-Liang Hsu, et al, random low vinyl styrene-isoprene copolymers, european Polymer Journal,2010, 46:2013-2018). US4048418 discloses a process for preparing poly-1, 3-pentadiene having 93% cis-1, 4-structure using an iron-based catalyst, in which the cis-isomer of the 1, 3-pentadiene monomer is an inert component and polymerization is difficult to initiate, thus resulting in a low overall monomer conversion.

CN104557660a discloses a barium dibenzopyrrole formate compound, a preparation method thereof, an anion initiating system and a preparation method of a copolymer; CN104557855a discloses dibenzothiophene barium formate compounds and their preparation method and anionic initiator system and preparation method of conjugated diene polymer; the two systems respectively adopt an organolithium/organoaluminium/alkoxy barium catalytic system of barium pyrrolecarboxylic acid and barium dibenzothiophene formate to prepare the styrene-butadiene-pentadiene ternary copolymer rubber with high trans-1, 4-structure content, the content of the styrene-butadiene-pentadiene ternary copolymer rubber under the two systems respectively reaches 87% and 88%, and meanwhile, the barium salt of the type has high boiling point of corresponding organic acid after the product is hydrolyzed, and the corresponding organic acid is not azeotroped with cyclohexane, so that the styrene-butadiene-pentadiene ternary copolymer rubber can be recovered in a condensing tower. However, the organic acid portion of the barium salt is expensive and is used in large amounts, which greatly increases the cost of production and equipment maintenance.

CN102351970a discloses a method for preparing poly-1, 3-pentadiene, which uses organic amine light rare earth system and lanthanide catalytic system to prepare poly-1, 3-pentadiene, the polymerization conversion rate can reach 50% at 50 ℃ for 7h, but the microstructure can not be precisely controlled, the polymer is mainly composed of cis-1, 4-structure (50%), and the rest is trans-1, 4-structure and cis-trans-isomerism 1,2 addition structure.

CN105585646a discloses a linear poly-1, 3-pentadiene with low propylene content and narrow molecular weight distribution and a preparation method thereof, which relates to a lithium system polymerization preparation method for linear poly-1, 3-pentadiene with low side propylene content, the molecular weight distribution PDI of the product is less than 1.2, the conversion rate is very fast, and the overall side propylene structure content formed by 1, 2-addition is less than 20%. However, the trans 1, 4-structure content can be controlled within the range of 40-70%, the elasticity of the polymer is reduced by a continuous propenyl structure, the Tg temperature is slightly increased, and the mechanical strength and low-temperature performance of the rubber used for high-performance tread or side wall are still required to be improved.

Therefore, research and development of a linear poly-1, 3-pentadiene elastomer with high trans-1, 4-structure content and a preparation method thereof are of great significance.

Disclosure of Invention

The invention aims to overcome the defect that the structure of preparing poly (1, 3-pentadiene) cannot be accurately controlled in the prior art, and provides a linear poly (1, 3-pentadiene) elastomer with high trans-1, 4-structure content, a preparation method and application thereof, wherein the elastomer has a trans-1, 4-structure of 50-95 mol percent, and in addition, the preparation method is simple, the conversion rate is high, and the microstructure can be efficiently regulated and controlled.

In order to achieve the above object, the present invention provides a linear high trans 1, 4-structure content poly 1, 3-pentadiene elastomer, wherein the poly 1, 3-pentadiene elastomer has a linear structure and the poly 1, 3-pentadiene elastomer comprises 50 to 95 mol% of trans 1, 4-structure, and the content of 1,4 to 4,1 head-to-tail linkages is 30 to 80 mol% in a microscopic sequence distribution of the poly 1, 3-pentadiene elastomer.

In a second aspect, the present invention provides a method for preparing a linear poly-1, 3-pentadiene elastomer having a high trans-1, 4-structure content, wherein the method comprises:

(1) Mixing 1, 3-pentadiene monomer with nonpolar hydrocarbon solvent for first preheating to obtain mixed solution;

(2) Contacting the mixed solution with a catalyst to perform second preheating or ageing treatment; the catalyst comprises a main catalyst and a cocatalyst, wherein the main catalyst comprises organic barium salt or organic sodium salt, and the cocatalyst is aluminum alkyl;

(3) And (3) contacting the product obtained in the step (2) with a polar regulator and an initiator to perform initiation polymerization reaction, and then performing termination reaction to obtain the linear poly-1, 3-pentadiene elastomer with a high trans-1, 4-structure.

In a third aspect, the present invention provides a linear high trans 1, 4-structure content poly-1, 3-pentadiene elastomer prepared by the aforementioned preparation method.

In a fourth aspect, the present invention provides the use of a linear high trans 1, 4-structure content poly-1, 3-pentadiene elastomer as described previously as a compound in a tire tread and/or sidewall.

Through the technical scheme, the technical scheme provided by the invention has the following advantages:

(1) The preparation method has the advantages of easily available raw materials, high reaction rate and high conversion rate.

(2) The molecular weight of the poly-1, 3-pentadiene elastomer prepared by the invention has wide designable range, and the number average molecular weight Mn is 2 multiplied by 10 ⁴ g/mol to 5X 10 ⁵ The molecular weight distribution is narrow between g/mol, the molecular weight distribution is far lower than that of 1, 3-pentadiene prepared by coordination polymerization in a narrow range, the microstructure can be efficiently regulated and controlled, the proportion of trans-1, 4-structure is very high, and meanwhile, the content of a side propenyl structure is very small; the sequence of the polymer is highly regular, and the 1,4-4,1 head-tail linkage mode is dominant.

Drawings

FIG. 1 shows the hydrogen nuclear magnetic resonance spectra of the poly (1, 3-pentadiene) elastomers prepared in example 1, example 14 and comparative example 1 of the present invention ¹ H NMR) map;

FIG. 2 shows nuclear magnetic resonance spectra of unsaturated carbon regions of the poly (1, 3-pentadiene) elastomers prepared in example 1, example 14 and comparative example 1 according to the present invention ¹³ C NMR) map;

FIG. 3 shows nuclear magnetic resonance spectra of saturated carbon regions of the poly (1, 3-pentadiene) elastomers prepared in example 1, example 14 and comparative example 1 of the present invention ¹³ C NMR) map;

FIG. 4 is a Gel Permeation Chromatograph (GPC) diagram of the poly (1, 3-pentadiene) elastomers prepared in example 1, example 10, example 14 and comparative example 1 of the present invention;

FIG. 5 is a differential calorimetric scan (DSC) of the poly (1, 3-pentadiene) elastomer prepared in example 1, example 10, example 14 and comparative example 1 of the present invention.

Detailed Description

The endpoints and any values of the ranges disclosed herein are not limited to the precise range or value, and are understood to encompass values approaching those ranges or values. For numerical ranges, one or more new numerical ranges may be found between the endpoints of each range, between the endpoint of each range and the individual point value, and between the individual point value, in combination with each other, and are to be considered as specifically disclosed herein.

As previously mentioned, a first aspect of the present invention provides a linear high trans 1, 4-structure content poly 1, 3-pentadiene elastomer, wherein the poly 1, 3-pentadiene elastomer has a linear structure and the poly 1, 3-pentadiene elastomer comprises from 50 to 95 mole percent trans 1, 4-structure and the content of 1,4 to 4,1 head-to-tail linkages in the microscopic sequence distribution of the poly 1, 3-pentadiene elastomer is from 30 to 80 mole percent.

The inventors of the present invention found that: the polar regulator is used for regulating the alkyl aluminum to initiate the polymerization of the 1, 3-pentadiene under the catalysis of the compounding of the optional organic barium salt or organic sodium salt and the alkyl aluminum, so that the raw materials of the components are easy to obtain, the reaction rate is high, and the conversion rate is high; in addition, the self-characteristics of anion polymerization by taking alkyl lithium as an initiator are that the molecular weight of the prepared poly-1, 3-pentadiene elastomer is easy to control and the molecular weight distribution is narrow; because the complex formed by organic barium salt or organic sodium salt and alkyl aluminum is more beneficial to the conversion of 1,3 pentadiene monomer into six-membered ring transition state in the polymerization process by sigma-allyl structure, the microstructure can be efficiently regulated and controlled, the ratio of trans-1, 4-structure is very high, and meanwhile, the content of side propenyl structure is very small; since n-butyllithium and tert-butyllithium do not undergo side reactions of branching or cyclization when initiating polymerization of 1, 3-pentadiene, the sequence of the polymer is highly regular, and the polymer chain presents a linear structure, wherein the 1,4-4,1 head-tail linkage mode is dominant.

According to the invention, the microstructure can be efficiently regulated and controlled, the proportion of trans-1, 4-structure is very high, and meanwhile, the content of side propenyl structure is very small; preferably, the poly-1, 3-pentadiene elastomer comprises from 70 to 95 mole% of trans-1, 4-structure; preferably, the poly-1, 3-pentadiene elastomer comprises 79 to 91 mole% of trans-1, 4-structure; more preferably, the poly-1, 3-pentadiene elastomer includes from 85 to 91 mole percent of trans-1, 4-structure.

According to the invention, the poly-1, 3-pentadiene elastomer further comprises 0 to 30 mole% of cis-1, 4-structure, 4 to 25 mole% of 1, 2-structure and 0 to 10 mole% of 3, 4-structure in each structural ratio of the poly-1, 3-pentadiene elastomer; preferably, the poly 1, 3-pentadiene elastomer comprises 0 to 15 mole% of cis 1, 4-structure, 7 to 15 mole% of 1, 2-structure and 0 to 3 mole% of 3, 4-structure.

According to the invention, the poly-1, 3-pentadiene elastomer has a highly ordered sequence and a predominantly 1,4-4,1 head-to-tail linkage, in the microscopic sequence distribution of the poly-1, 3-pentadiene elastomer:

the content of the 1,4-4,1 head-to-tail linkage is 45 to 80 mol%, preferably 51 to 78 mol%, preferably 65 to 80 mol%, more preferably 71 to 79 mol%.

The total content of head-to-head 1, 4-to-1, 4-and tail-to-tail 4, 1-to-1 linkages is 10-40 mole%, preferably 10-33 mole%, more preferably 10-20 mole%; in addition, the ratio of the contents of 1,4-1,4 and 4,1-4,1 is 1: (1-5), preferably 1:1, a step of;

the content of the 1,4-1, 2-linkage is 5 to 20 mol%, preferably 5 to 10 mol%.

In the present invention, other linking means are also included in a small amount, and preferably the linking means is in an amount of 0 to 20 mol%, preferably 0 to 12 mol%.

According to the invention, the molecular weight of the poly-1, 3-pentadiene elastomer can be designed in a wide range, the number average molecular weight Mn of the poly-1, 3-pentadiene elastomer being 2X 10 ⁴ g/mol to 5X 10 ⁵ g/mol。

According to the present invention, the molecular weight distribution is narrow, and the molecular weight distribution PDI (pdi=weight average molecular weight Mw/number average molecular weight Mn) is 1.05 to 2.5, preferably 1.1 to 1.9, more preferably 1.26 to 1.88; in the invention, the microstructure of the poly-1, 3-pentadiene elastomer prepared by coordination polymerization is far lower than that of the poly-1, 3-pentadiene elastomer in the PDI range, the microstructure can be efficiently regulated, the proportion of trans-1, 4-structure is very high, and meanwhile, the content of a side propenyl structure is very small.

According to the invention, the glass transition temperature T of the poly-1, 3-pentadiene elastomer is determined by DSC _g From-70 ℃ to-30 ℃, preferably from-70 ℃ to-50 ℃; melting temperature T _m From 0 to 90℃and preferably from 70 to 90 ℃.

(3) And (3) contacting the product obtained in the step (2) with a polar regulator and an initiator to perform initiation polymerization reaction, and then performing termination reaction to obtain the linear poly-1, 3-pentadiene elastomer with high trans-1, 4-structure content.

In the present invention, in the step (2), when the catalyst is an organic sodium salt, aging treatment is not required.

According to the invention, the catalyst used in the catalytic-initiation reaction system is composed of a main catalyst and a cocatalyst under anhydrous and anaerobic conditions, wherein the molar ratio of the cocatalyst to the main catalyst is (0-100): 1, preferably (0-4): 1.

according to the invention, the main catalyst is organic barium salt or organic sodium salt which can be used for preparing trans-poly conjugated olefin by lithium system; in the invention, the organic barium salt is selected from one or more of alkoxy barium salt, cycloalkoxy barium salt, alcohol ether barium salt, alcohol amine barium salt, phenol barium salt and carboxylic acid barium salt; preferably, the organic barium salt is selected from one or more of menthol barium, thymol Barium (BHT), diethylene glycol monoethyl ether Barium (BAD), morpholine ethanol barium, dodecyl benzene sulfonate barium, tetrahydrofurfuryl acid barium, and tetrahydrofurfuryl alcohol barium; more preferably, the organic barium salt is barium thymol and/or barium diethylene glycol monoethyl ether.

According to the invention, the organic sodium salt is an alkoxy sodium salt and/or a sodium sulfonate salt; preferably, the organic sodium salt is selected from one or more of Sodium Dodecyl Sulfate (SDS), sodium p-toluene sulfonate, sodium Dodecyl Benzene Sulfonate (SDBS), sodium tetrahydrofurfuryl alcohol and sodium tert-amyl alcohol, preferably sodium dodecyl benzene sulfonate and sodium dodecyl sulfate.

According to the invention, the cocatalyst is an alkylaluminum, wherein the alkylaluminum is selected from one or more of Trimethylaluminum (TMA), triethylaluminum (TEA), tripropylaluminum, triisobutylaluminum (TIBA), triisopropylaluminum, trioctylaluminum and methylaluminoxane, preferably trimethylaluminum, triethylaluminum and triisobutylaluminum.

According to the present invention, the nonpolar hydrocarbon solvent is selected from one or more of cyclohexane, n-hexane, n-pentane, n-heptane, benzene, hydrogenated oil and extracted oil, preferably cyclohexane; wherein benzene includes toluene, ethylbenzene and xylenes.

According to the invention, the polarity modifier is selected from one or more of Tetrahydrofuran (THF), dioxane, triethylamine, ditetrahydrofuran propane, N-dimethyltetrahydrofurfuryl amine, tetrahydrofurfuryl alcohol ethyl ether, tetrahydrofurfuryl alcohol butyl ether, pentamethyldiethyl triamine, dipiperidine ethane, triphenylphosphine and carbon disulphide, preferably one or more of tetrahydrofuran, tetrahydrofurfuryl alcohol ethyl ether and carbon disulphide.

According to the invention, the initiator is an organolithium initiator; preferably, the initiator is selected from one or more of alkyl lithium, aryl lithium, amine lithium, organo lithium chloride and macromolecular active lithium; wherein the alkyl lithium is n-butyl lithium (n-BuLi), sec-butyl lithium, tert-butyl lithium (t-BuLi) or methyl lithium; aryl lithium is phenyl lithium or benzyl lithium; the amine lithium is dimethylamino lithium, diethylamino lithium or diisopropylamino lithium; the organic lithium chloride is n-butyl lithium chloride and isobutyl lithium chloride; the macromolecular active lithium is polystyrene active lithium, polybutadiene active lithium, polyisoprene active lithium or poly 1, 3-hexadiene active lithium. Preferred are n-butyllithium, sec-butyllithium, tert-butyllithium, polystyrene-based active lithium and polybutadiene-based active lithium.

In the invention, the polystyrene-based active lithium initiator PSLi synthesis method comprises the following steps:

under the anhydrous and anaerobic condition, 25mL of styrene cyclohexane solution containing 5% mass fraction is added into a polymerization bottle which is subjected to drying, nitrogen filling and vacuum pumping treatment, 1.3mL of n-butyl lithium initiator (0.4 mol/L of cyclohexane solution and polystyrene segment design molecular weight Mn of 2,000 g/mol) is added for reaction for 2h at 60 ℃, and the reaction is sealed under the inert gas atmosphere for preservation after the reaction is finished. Determination of PSLi Using GPC results [ Li ⁺ ]Is a concentration of (3).

In the invention, the polybutadiene alkenyl active lithium initiator PBLi synthesis method is as follows:

under the anhydrous and anaerobic condition, 25mL of butadiene cyclohexane solution containing 3% mass fraction is added into a polymerization bottle which is subjected to drying, nitrogen filling and vacuum pumping treatment, 0.75mL of n-butyl lithium initiator (0.4 mol/L of cyclohexane solution and 2,000g/mol of polybutadiene alkenyl segment design molecular weight Mn) is added for reaction for 2h at 70 ℃, and the reaction is sealed under the inert gas atmosphere for preservation after the reaction is finished. Determination of [ Li ] in PBLi by GPC results ⁺ ]Is a concentration of (3).

According to the invention, the 1, 3-pentadiene monomer used is selected from cis-1, 3-pentadiene (Zp), trans-1, 3-pentadiene (Ep), mixed isomerism 1, 3-pentadiene (Pd), 2-methyl-1, 3-pentadiene (Mpd), 2, 3-dimethyl-1, 3-pentadiene (Dmpd) in any ratio; preference is given to cis-1, 3-pentadiene (Zp), trans-1, 3-pentadiene (Ep) and the specific ratio of the mixed isomeric 1, 3-pentadienes (Pd, E/z=65/35).

According to the invention, the molar ratio of the total amount of cocatalyst to procatalyst to the amount of initiator is (0.01-100): 1, preferably (0.2-1.53): 1.

according to the invention, the molar ratio of the polar regulator to the initiator is (0.1-100): 1, preferably (10-20): 1.

According to the invention, the molar ratio of 1, 3-pentadiene monomer to the amount of initiator used is (200-1000): 1, preferably (294-735): 1, more preferably (588-735): 1. the ratio of monomer to initiator is generally related by defining a designed molecular weight, e.g., a designed molecular weight of 50,000g/mol, i.e., an actual molar ratio of (monomer: initiator) 735:1; if the molecular weight is designed to be 20,000g/mol, i.e., the actual molar ratio is (monomer: initiator) 588:1.

According to the present invention, in step (1), the concentration of 1, 3-pentadiene monomer in the mixed solution of 1, 3-pentadiene and nonpolar hydrocarbon solvent used is 5 to 20% by weight, preferably 8 to 15% by weight.

According to the present invention, the first preheating conditions include: the temperature is 25-80 ℃ and the time is 0.5-3h.

According to the present invention, the second preheating conditions include: the temperature is 50-60 ℃ and the time is 4-5h.

According to the invention, the aging treatment conditions include: the temperature is 25-60deg.C, and the time is 10-300min.

According to the invention, the polymerization conditions include: the temperature is 0-100deg.C, and the time is 1-24h.

According to the invention, after the polymerization is finished, 0.5-3mL of aqueous solution or alcohol solution containing an anti-aging agent and an antioxidant is added to terminate the reaction, and after excessive methanol is precipitated, the reaction is dried in vacuum at 40-60 ℃ for 24-72h.

In the present invention, the anti-aging agent is selected from the group consisting of anti-aging agent 264 and/or anti-aging agent 2264.

In the present invention, the antioxidant is selected from one or more of antioxidant 1010, antioxidant 168 and antioxidant 1076.

According to the present invention, the terminator used in the termination reaction is generally selected from any one of water, methanol, ethanol and isopropanol, preferably isopropanol.

According to a preferred embodiment of the present invention, a process for preparing a linear high trans 1, 4-structure content poly-1, 3-pentadiene elastomer comprises:

(1) Preparing a mixed solution of a polymerization-grade 1, 3-pentadiene monomer and a nonpolar hydrocarbon solvent, and adding the mixed solution into a polymerization bottle which is baked, filled with nitrogen and deoxidized; preheating a polymerization bottle for 0.5-3h at 25-80 ℃;

(2) Adding a catalyst into the mixed solution, preheating for 4-5 hours at 50-60 ℃, and aging for 10-300 minutes at 25-60 ℃; wherein the catalyst comprises two components of a cocatalyst and a main catalyst according to the molar ratio of (0-4): 1, wherein the main catalyst is alkoxy barium salt, cycloalkoxy barium salt, alcohol ether barium salt, alcohol amine barium salt, phenol barium salt, carboxylic acid barium salt, alkoxy sodium salt and sulfonic acid sodium salt; the cocatalyst is aluminum alkyl;

(3) Adding a polarity regulator and an organic lithium initiator to initiate polymerization after the aging is finished and the impurities are broken, wherein the polymerization temperature is 0-100 ℃ and the polymerization time is 1-24 hours; the molar ratio of the total amount of the cocatalyst to the main catalyst to the organolithium initiator is (0.2-1.53): 1, a step of; the molar ratio of the polar regulator to the organic lithium initiator is (10-20): 1;

(4) And (3) adding 0.5-3mL of alcohol solution containing an antioxidant and an antioxidant to terminate the reaction after polymerization, precipitating excessive methanol, and then vacuum-drying at 40-60 ℃ for 24-72h to obtain the poly-1, 3-pentadiene elastomer with high trans-1, 4-structure content.

In the present invention, the poly-1, 3-pentadiene elastomer is a homopolymer.

The present invention will be described in detail by examples.

The microstructure of the synthesized polymer was measured using a nuclear magnetic resonance apparatus model INOVA-400, manufactured by Varian, inc. of America, at a frequency of 400MHz, with Tetramethylsilane (TMS) as an internal standard and deuterated chloroform as a solvent.

The molecular weight and molecular weight distribution were measured by gel permeation chromatograph model GPC-220, manufactured by PL company, england, and the eluent was THF at a flow rate of 1.0mL/min and a test temperature of 40 ℃.

The glass transition temperature was measured by DSC200F3 differential calorimeter scanner manufactured by Kagaku Kogyo Co., ltd. Heating to 25-100deg.C at 10deg.C/min for 10min; cooling to 100-100 deg.c at 5 deg.c/min; the temperature is raised for the second time (-100) to 150 ℃ and 5 ℃/min; sweep gas: nitrogen, 50mL/min; protective gas: nitrogen, 50mL/min.

The 1, 3-pentadiene monomer, solvent and terminator used in the polymerization reaction are subjected to strict operations of removing water and oxygen, and the water and oxygen content reaches the requirement of anion polymerization.

The organic sodium salts SDBS, SDS and organic barium salt BAD, BHT can be obtained from commercial purchase or prepared according to the existing public common synthetic route when preparing the catalyst and the reaction system. N-butyllithium, t-butyllithium, sec-butyllithium, antioxidant 1010 and antioxidant 264 are all available from Baling petrochemical company.

In the present invention, the formulation and the molar ratio of the main catalyst, the cocatalyst, the polarity regulator or the organolithium initiator in the catalytic-initiation reaction systems a to h in the comparative examples and examples are as follows:

organic barium catalyst:

system a: n (BHT): n (TEA): n (THF): n (t-BuLi) =0.25:0.25:10:1

System b: n (BHT): n (TEA): n (t-BuLi) =0.25:0.75:1

System c: n (BHT): n (TMA): n (t-BuLi) =0.33:1.2:1

And (3) a system d: n (BHT): n (TIBA): n (t-BuLi) =0.16:0.32:1

System e: n (BAD): n (TEA): n (t-BuLi) =0.25:0.50:1

Organic sodium catalyst:

and (3) a system f: n (SDBS): n (THF): n (n-BuLi) =0.2:20:1

System g: n (SDS): n (THF): n (n-BuLi) =0.2:10:1

Unipolar regulator system:

and (3) a system h: n (THF): n (t-BuLi) =20:1

Example 1

This example is intended to illustrate a poly-1, 3-pentadiene elastomer prepared using the organobarium catalyst system in the process of the present invention.

(1) 250mL of cyclohexane and 21.75g (0.33 mol) of cis-1, 3-pentadiene (Zp) are sequentially added into a pressure-resistant polymerization bottle which is subjected to dry nitrogen filling and vacuum pumping under the anhydrous and anaerobic condition; preheating for 30 minutes at 50 ℃;

(2) After preheating, adding 0.67mL (0.32 mol/L,0.216mmol and toluene solution) of thymol barium BHT serving as a main catalyst of the system a, 2.2mL (0.1 mol/L,0.216mmol and toluene solution) of triethylaluminum TEA, fully mixing, standing and aging for 1h at 50 ℃;

(3) After aging, adding 0.7mL (8.65 mmol) of THF, breaking impurities by using t-butyllithium t-BuLi until the solution develops color, adding 1.3mL (0.33 mol/L of cyclohexane solution, 0.865 mmol) of t-butyllithium t-BuLi, and reacting at 80 ℃ for 4h, wherein the designed molecular weight Mn of the poly-1, 3-pentadiene elastomer is 50,000 g/mol;

(4) After the reaction is finished, cooling to room temperature, adding isopropanol-toluene solution containing 1% of an anti-aging agent 264 and 1% of an antioxidant 1010 to terminate the reaction, repeatedly washing for 3-4 times after excessive methanol is precipitated, and vacuum drying at 40 ℃ for 24 hours to obtain a polymerization product. The monomer conversion was found to be 95% by weight.

¹ H NMR analysis showed that the poly-1, 3-pentadiene elastomer had a Trans-1, 4-structure (Trans-1, 4-structure) content of 88% and a 1, 2-structure content of 12% and was substantially free of 3, 4-structure and Cis-1, 4-structure (Cis-1, 4-structure).

The molecular weight distribution pdi=1.45 of the polymer obtained has a glass transition temperature tg= -54 ℃, a distinct melting peak, an onset temperature of 47 ℃, and a midpoint temperature Tm of 76 ℃.

The sequence composition of the polymer is shown in Table 1.

Example 2

Poly (1, 3-pentadiene) elastomer was prepared according to the same organobarium catalyst and alkyllithium polymerization conditions as in example 1, except that: the anionic polymerization of 1, 3-pentadiene was carried out using "trans-1, 3-pentadiene (Ep)" instead of "cis-1, 3-pentadiene (Zp)" in example 1. The polymer obtained was dried to remove the solvent, and the monomer conversion was 91% by weight.

¹ H NMR analysis shows that the poly (1, 3-pentadiene) elastomer has a trans-1, 4-structure content of 79%, a 1, 2-structure content of 15.7%, and a cis-1, 4-structure content of 6.4% and is substantially free of 3, 4-structures.

The molecular weight distribution pdi=1.77 of the obtained polymer, the glass transition temperature tg= -46 ℃, no cold crystallization peak and no obvious melting peak appear.

The sequence composition of the polymer is shown in Table 1.

Example 3

Poly (1, 3-pentadiene) elastomer was prepared according to the same organobarium catalyst and alkyllithium polymerization conditions as in example 1, except that: the anionic polymerization of 1, 3-pentadiene was carried out by changing only the monomer type and replacing "cis-1, 3-pentadiene (Zp)" in example 1 with "mixed isomerism 1, 3-pentadiene (Pd, E/z=65/35)". The polymer obtained was dried with the solvent removed, and the monomer conversion was 94% by weight.

¹ H NMR analysis shows that the poly (1, 3-pentadiene) elastomer has a trans-1, 4-structure content of 82%, a 1, 2-structure content of 16.2%, and a cis-1, 4-structure content of 1.8% and is substantially free of 3, 4-structures.

The molecular weight distribution pdi=1.62 of the obtained polymer, the glass transition temperature tg= -48 ℃, the cold crystallization peak at-4 ℃ and no obvious melting peak.

The sequence composition of the polymer is shown in Table 1.

Example 4

Poly (1, 3-pentadiene) elastomer was prepared according to the same organobarium catalyst and alkyllithium polymerization conditions as in example 1, except that: only the organolithium type was changed, and the polymerization of 1, 3-pentadiene was carried out by replacing "t-butyllithium t-BuLi" in example 1 with "n-butyllithium n-BuLi (0.40 mol/L, cyclohexane solution, design molecular weight Mn of poly-1, 3-pentadiene elastomer: 50,000 g/mol)". The polymer obtained was dried with the solvent removed, and the monomer conversion was 93% by weight.

¹ H NMR results showed that the poly (1, 3-pentadiene) elastomer had a trans-1, 4-structure content of 85% and a 1, 2-structure content of 14.9% and was substantially free of 3, 4-structure and cis-1, 4-structure.

The molecular weight distribution pdi=1.42 of the polymer obtained has a glass transition temperature tg= -49 ℃, a distinct melting peak, an onset temperature of 42 ℃ and a midpoint temperature Tm of 69 ℃.

The sequence composition of the polymer is shown in Table 1.

Example 5

Poly (1, 3-pentadiene) elastomer was prepared according to the same organobarium catalyst and alkyllithium polymerization conditions as in example 1, except that: only the organolithium type was changed, and the polymerization of 1, 3-pentadiene was carried out by replacing "t-butyllithium t-BuLi" in example 1 with "sec-butyllithium s-BuLi (0.29 mol/L in n-hexane solution, design molecular weight Mn of the poly-1, 3-pentadiene elastomer: 50,000 g/mol)". The polymer obtained was dried with the solvent removed, and the monomer conversion was 92% by weight.

¹ H NMR analysis shows that the poly (1, 3-pentadiene) elastomer has a trans-1, 4-structure content of 84%, a cis-1, 4-structure content of 0.7%, and a 1, 2-structure content of 15.3% and is substantially free of 3, 4-structures.

The molecular weight distribution pdi=1.73 of the polymer obtained has a glass transition temperature tg= -51 ℃, a distinct melting peak, an onset temperature of 39 ℃ and a midpoint temperature Tm of 68 ℃.

The sequence composition of the polymer is shown in Table 1.

Example 6

Poly (1, 3-pentadiene) elastomer was prepared according to the same organobarium catalyst and alkyllithium polymerization conditions as in example 1, except that: the polymerization of 1, 3-pentadiene was carried out by replacing the "t-butyllithium t-BuLi" in example 1 with "large-molecular active lithium polystyrene-based active lithium (cyclohexane solution of PSLi, polystyrene design molecular weight Mn of 2,000g/mol, design molecular weight Mn of poly-1, 3-pentadiene elastomer of 50,000 g/mol)". The polymer obtained was dried with the solvent removed, and the monomer conversion was 95% by weight.

¹ The H NMR analysis showed that the trans 1, 4-structure content of the poly-1, 3-pentadiene elastomer segment was 89% and the 1, 2-structure content was 10.9%, essentially free of 3, 4-structure and cis 1, 4-structure.

The molecular weight distribution pdi=1.81 of the polymer obtained has a glass transition temperature tg= -52 ℃, a distinct melting peak, an onset temperature of 45 ℃ and a midpoint temperature Tm of 78 ℃.

The sequence composition of the polymer is shown in Table 1.

Example 7

Poly (1, 3-pentadiene) elastomer was prepared according to the same organobarium catalyst and alkyllithium polymerization conditions as in example 1, except that: the polymerization of 1, 3-pentadiene was carried out by replacing "t-butyllithium t-BuLi" in example 1 with "large molecular active lithium polybutadiene-based active lithium (cyclohexane solution of PBLi, polybutadiene design molecular weight Mn of 2,000g/mol, design molecular weight Mn of poly-1, 3-pentadiene elastomer of 50,000 g/mol)". The polymer obtained was dried with the solvent removed, and the monomer conversion was determined by a gravimetric method to be 96%.

¹ The H NMR analysis showed that the trans 1, 4-structure content of the poly-1, 3-pentadiene elastomer segment was 88% and the 1, 2-structure content was 12% and the poly-1, 3-and cis-1, 4-structures were substantially absent.

The molecular weight distribution pdi=1.73 of the polymer obtained has a glass transition temperature tg= -46 ℃, a distinct melting peak, an onset temperature of 48 ℃ and a midpoint temperature Tm of 81 ℃.

The sequence composition of the polymer is shown in Table 1.

Example 8

Poly (1, 3-pentadiene) elastomer was prepared according to the same organobarium catalyst and alkyllithium polymerization conditions as in example 1, except that: only the ratio of cis-1, 3-pentadiene monomer to initiator was varied, specifically:

in the step (2), 0.67mL (0.32 mol/L,0.216mmol, toluene solution) of "thymol barium BHT" was modified to 1.68mL (0.32 mol/L,0.54mmol, toluene solution) "of" thymol barium BHT; "triethylaluminum TEA 2.2mL (0.1 mol/L,0.216mmol, toluene solution)" was modified to "triethylaluminum TEA 5.5mL (0.1 mol/L,0.54mmol, toluene solution)";

in the step (3), 1.3mL (0.33 mol/L, cyclohexane solution, 0.865 mmol) of "t-butyllithium t-BuLi" was modified to 3.2mL (0.33 mol/L, cyclohexane solution, 2.16mmol ");

namely, the anionic polymerization of 1, 3-pentadiene was carried out by changing the designed molecular weight Mn of the poly-1, 3-pentadiene elastomer to 20,000 g/mol. The polymer obtained was dried with the solvent removed, and the monomer conversion was 97% by weight.

¹ H NMR analysis shows that the poly (1, 3-pentadiene) elastomer has a trans-1, 4-structure content of 86%, a cis-1, 4-structure content of 0.7%, and a 1, 2-structure content of 13.3% and is substantially free of 3, 4-structures.

The molecular weight distribution pdi=1.51 of the obtained polymer, the glass transition temperature tg= -49 ℃, the cold crystallization peak at-8 ℃ and no obvious melting peak.

The sequence composition of the polymer is shown in Table 1.

Example 9

Poly (1, 3-pentadiene) elastomer was prepared according to the same organobarium catalyst and alkyllithium polymerization conditions as in example 1, except that: only the type of the polarity regulator was changed, and anionic polymerization of 1, 3-pentadiene was carried out with "tetrahydrofurfuryl alcohol ethyl ether (1.2 mL,8.65 mmol)" instead of "THF" as the polarity regulator. The polymer obtained was dried to remove the solvent, and the monomer conversion was 91% by weight.

¹ The H NMR analysis results showed thatThe poly (1, 3-pentadiene) elastomer has a trans-1, 4-structure content of 91% and a 1, 2-structure content of 7%, is substantially free of cis-1, 4-structures and contains a small amount of 3, 4-structures, ¹³ C NMR analysis gave a content of about 2.0%.

The molecular weight distribution pdi=1.49 of the obtained polymer has a glass transition temperature tg= -55 ℃, a distinct melting peak, an onset temperature of 59 ℃ and a midpoint temperature Tm of 84 ℃.

The sequence composition of the polymer is shown in Table 1.

Example 10

Poly (1, 3-pentadiene) elastomer was prepared according to the same organobarium catalyst and alkyllithium polymerization conditions as in example 1, except that: the anionic polymerization of 1, 3-pentadiene is carried out with "catalytic system of system b" with only varying initiator types. The polymer obtained was dried with the solvent removed, and the monomer conversion was 93% by weight. The DSC curve is shown in FIG. 2.

¹ H NMR analysis results show that the trans 1, 4-structure content in the poly 1, 3-pentadiene elastomer is 86%, the cis 1, 4-structure content is 0.9%, the 1, 2-structure content is 13%, and the poly 1, 3-pentadiene elastomer is basically free of 3, 4-structures; the sequence composition of the polymer is shown in Table 1.

The molecular weight distribution pdi=1.66 of the obtained polymer has a glass transition temperature tg= -51 ℃, a distinct melting peak, an onset temperature of 42 ℃, and a midpoint temperature Tm of 71 ℃.

The sequence composition of the polymer is shown in Table 1.

Example 11

Poly (1, 3-pentadiene) elastomer was prepared according to the same organobarium catalyst and alkyllithium polymerization conditions as in example 1, except that: the anionic polymerization of 1, 3-pentadiene is carried out with "catalytic system of system c" with only varying initiator types. The polymer obtained was dried with the solvent removed, and the monomer conversion was determined by a gravimetric method to be 90%.

¹ H NMR analysis shows that the poly (1, 3-pentadiene) elastomer has a trans-1, 4-structure content of 83%, a cis-1, 4-structure content of 6%, a 1, 2-structure content of 11% and substantially no 3, 4-structure.

The molecular weight distribution pdi=1.58 of the obtained polymer, the glass transition temperature tg= -48 ℃, the cold crystallization peak at-6 ℃ and no obvious melting peak.

The sequence composition of the polymer is shown in Table 1.

Example 12

Poly (1, 3-pentadiene) elastomer was prepared according to the same organobarium catalyst and alkyllithium polymerization conditions as in example 1, except that: the anionic polymerization of 1, 3-pentadiene is carried out with "catalytic system of system d" with only varying initiator types. The polymer obtained was dried with the solvent removed, and the monomer conversion was 93% by weight.

¹ H NMR analysis results show that the poly (1, 3-pentadiene) elastomer has a trans-1, 4-structure content of 89%, a cis-1, 4-structure content of 0.5%, a 1, 2-structure content of 11% and substantially no 3, 4-structure.

The molecular weight distribution pdi=1.54 of the polymer obtained has a glass transition temperature tg= -54 ℃, a distinct melting peak, an onset temperature of 55 ℃ and a midpoint temperature Tm of 79 ℃.

The sequence composition of the polymer is shown in Table 1.

Example 13

Poly (1, 3-pentadiene) elastomer was prepared according to the same organobarium catalyst and alkyllithium polymerization conditions as in example 1, except that: the anionic polymerization of 1, 3-pentadiene is carried out with "catalytic system of system e" with only varying initiator types. The polymer obtained was dried with the solvent removed, and the monomer conversion was 97% by weight.

¹ H NMR analysis results showed that the poly (1, 3-pentadiene) elastomer had a trans-1, 4-structure content of 83%, a cis-1, 4-structure content of 2.2%, a 1, 2-structure content of 13.1% and a small amount of 3, 4-structure.

The molecular weight distribution pdi=1.75 of the obtained polymer, the glass transition temperature tg= -47 ℃, the cold crystallization peak at 5 ℃ and no obvious melting peak appear.

The sequence composition of the polymer is shown in Table 1.

Example 14

This example is intended to illustrate a poly-1, 3-pentadiene elastomer prepared using the organic sodium catalytic system in the process of the present invention.

(1) 100mL of cyclohexane and 8.7g (0.13 mol) of cis-1, 3-pentadiene (Zp) are sequentially added into a polymerization bottle which is subjected to dry nitrogen filling and vacuum pumping treatment under the anhydrous and anaerobic condition, and the mixture is preheated for 30 minutes at 50 ℃;

(2) After preheating, add system f, wherein SDBS 0.012g (0.0346 mmol), THF 0.22mL (3.46 mmol), 0.40mol/L n-BuLi cyclohexane solution 0.48mL (0.173 mmol, designed molecular weight Mn 50,000 g/mol), react at 75deg.C for 4h;

(3) After the reaction is finished, cooling to room temperature, adding isopropanol-toluene solution containing 1% of an antioxidant 264 and 1% of an antioxidant 1010 to terminate the reaction, repeatedly washing for 3-4 times after excessive methanol is precipitated, and vacuum drying at 40 ℃ for 24 hours to obtain a polymerization product poly-1, 3-pentadiene elastomer, wherein the monomer conversion rate is 99% by a gravimetric method.

¹ H NMR analysis result shows that the trans 1, 4-structure content in the poly 1, 3-pentadiene elastomer is 81%, the cis 1, 4-structure content is 6.6%, the 1, 2-structure content is 12.5%, and the poly 1, 3-pentadiene elastomer is basically free of 3, 4-structure;

the molecular weight distribution pdi=1.37 of the obtained polymer, the glass transition temperature tg= -52 ℃, the cold crystallization peak at-7 ℃ and no obvious melting peak.

The sequence composition of the polymer is shown in Table 1.

Example 15

Poly (1, 3-pentadiene) elastomer was prepared according to the same polymerization conditions as in example 14 using an organosodium catalyst and an alkyllithium, except that: the anionic polymerization of 1, 3-pentadiene was carried out with the "cis-1, 3-pentadiene (Zp)" in example 14 replaced with "trans-1, 3-pentadiene (Ep)" only by changing the monomer type. The polymer obtained was dried with the solvent removed, and the monomer conversion was 97% by weight.

¹ H NMR analysis shows that the poly (1, 3-pentadiene) elastomer has a trans-1, 4-structure content of 77%, a cis-1, 4-structure content of 10.2%, and a 1, 2-structure content of 12.9% and is substantially free of 3, 4-structures.

The molecular weight distribution pdi=1.46 of the obtained polymer has a glass transition temperature tg= -39 ℃, no cold crystallization peak and no obvious melting peak.

The sequence composition of the polymer is shown in Table 1.

Example 16

Poly (1, 3-pentadiene) elastomer was prepared according to the same polymerization conditions as in example 14 using an organosodium catalyst and an alkyllithium, except that: the anionic polymerization of 1, 3-pentadiene was carried out with only the monomer type changed, with "mixed isomerism 1, 3-pentadiene (Pd, E/z=65/35)" replacing "cis-1, 3-pentadiene (Zp)". The polymer obtained was dried with the solvent removed, and the monomer conversion was 98% by weight.

¹ H NMR analysis shows that the poly (1, 3-pentadiene) elastomer has a trans-1, 4-structure content of 79%, a cis-1, 4-structure content of 9.7%, and a 1, 2-structure content of 10.3% and is substantially free of 3, 4-structures.

The molecular weight distribution pdi=1.39 of the obtained polymer has a glass transition temperature tg= -45 ℃, no cold crystallization peak and no obvious melting peak.

The sequence composition of the polymer is shown in Table 1.

Example 17

Poly (1, 3-pentadiene) elastomer was prepared according to the same polymerization conditions as in example 14 using an organosodium catalyst and an alkyllithium, except that: only the ratio of SDBS to THF was changed, namely, 0.025g (0.0865 mmol) of SDBS and 0.11mL (1.73 mmol) of THF were used for anionic polymerization of 1, 3-pentadiene. The polymer obtained was dried with the solvent removed, and the monomer conversion was 95% by weight.

¹ H NMR analysis results show that the trans 1, 4-structure content in the poly-1, 3-pentadiene elastomer is 80%, the cis 1, 4-structure content is 14.5%, the 1, 2-structure content is 4.2%, and a small amount of 3, 4-structure is contained, ¹³ c NMR analysis gave about 1.3% of the total content. The molecular weight distribution PDI of the resulting polymer=1.26,

The glass transition temperature Tg= -52 ℃, cold crystallization peak appears at 0 ℃, and no obvious melting peak appears.

The sequence composition of the polymer is shown in Table 1.

Example 18

Poly (1, 3-pentadiene) elastomer was prepared according to the same polymerization conditions as in example 14 using an organosodium catalyst and an alkyllithium, except that: only the type of the polarity regulator is changed, and 'THF' is replaced by 'carbon disulfide' as the polarity regulator, SDBS0.025g (0.0865 mmol) and CS are adopted ₂ 0.21mL (3.46 mmol) of 1, 3-pentadiene was polymerized anionically. The polymer obtained was dried with the solvent removed, and the monomer conversion was 93% by weight.

¹ H NMR analysis results showed that the trans 1, 4-structure content in the poly-1, 3-pentadiene elastomer was 82%, the cis 1, 4-structure content was 12.1%, and 1,2-The structural content is 5.9%, and the composition is basically free of 3, 4-structure.

The molecular weight distribution pdi=1.51 of the obtained polymer, the glass transition temperature tg= -50 ℃, the cold crystallization peak at 3 ℃ and no obvious melting peak appear.

The sequence composition of the polymer is shown in Table 1.

Example 19

Poly (1, 3-pentadiene) elastomer was prepared according to the same polymerization conditions as in example 14 using an organosodium catalyst and an alkyllithium, except that: anionic polymerization of 1, 3-pentadiene with "System g System" with only varying initiator type, SDBS0.025g (0.0865 mmol), CS ₂ 0.21mL (3.46 mmol) of 1, 3-pentadiene was polymerized anionically. The polymer obtained was dried to remove the solvent, and the monomer conversion was 99% by weight.

¹ H NMR analysis shows that the poly (1, 3-pentadiene) elastomer has a trans-1, 4-structure content of 71%, a cis-1, 4-structure content of 18.9%, a 1, 2-structure content of 10.2% and substantially no 3, 4-structure.

The molecular weight distribution pdi=1.88 of the obtained polymer has a glass transition temperature tg= -44 ℃, no cold crystallization peak and no obvious melting peak.

The sequence composition of the polymer is shown in Table 1.

Comparative example 1

100mL of cyclohexane, 8.7g (0.13 mol) of mixed isomeric 1, 3-pentadiene (Pd, E/Z=65/35) are added in succession to a dry nitrogen-filled evacuated polymerization flask under anhydrous and anaerobic conditions. After the polymerization flask was preheated at 50℃for 30 minutes, system h was charged with 0.22mL (3.46 mmol) of THF and 0.48mL (0.173 mmol) of n-BuLi (designed molecular weight Mn: 50,000 g/moL) and reacted at 75℃for 4 hours. After the reaction is finished, cooling to room temperature, adding isopropanol-toluene solution containing 1% of an anti-aging agent 264 and 1% of an antioxidant 1010 to terminate the reaction, repeatedly washing for 3-4 times after excessive methanol is precipitated, and vacuum drying at 40 ℃ for 24 hours to obtain a polymerization product, wherein the monomer conversion rate is 95% by a gravimetric method.

¹ The H NMR analysis result shows that the trans 1, 4-structure content in the poly-1, 3-pentadiene elastomer is 46%, the cis 1, 4-structure content is 17%, the 1, 2-structure content is 30%, the poly-1, 3-pentadiene elastomer contains a small amount of 3, 4-structure, ¹³ c NMR analysis gave a 3, 4-content of about 7.0%.

The molecular weight distribution pdi=1.19 of the obtained polymer had a glass transition temperature tg= -44 ℃, no cold crystallization peak nor obvious melting peak.

The sequence composition of the polymer is shown in Table 1.

FIG. 1 shows the hydrogen nuclear magnetic resonance spectra of the poly (1, 3-pentadiene) elastomers prepared in example 1, example 14 and comparative example 1 of the present invention ¹ H NMR) diagram, as can be seen from fig. 1: the saturation H characteristic peak in the cis-1, 4-structure corresponding to δ2 (2.5 ppm), the 1, 2-structure corresponding to δ4 (1.6 ppm) and δ5 (1.3 ppm) and the saturation H characteristic peak in the cis-1, 4-structure corresponding to δ6 (1.0 ppm), the methyl H characteristic peak in the 1, 4-structure content corresponding to δ6, the δ2 signal of example 1 and that of example 14 were extremely low, δ4 and δ5 were also extremely low with respect to comparative example 1, and the two characteristic peaks of example 1 were the lowest, indicating that the trans-1, 4-structure was the main in the poly-1, 3-pentadiene elastomers obtained by the methods of example 1 and example 14, and that the trans-1, 4-structure in example 1 was relatively higher.

FIG. 2 shows nuclear magnetic resonance spectra of unsaturated carbon regions of the poly (1, 3-pentadiene) elastomers prepared in example 1, example 14 and comparative example 1 according to the present invention ¹³ C NMR) diagram, as can be seen from fig. 2: the unsaturated carbon regions of examples 1 and 14 are mainly represented by two unsaturated carbons C2 and C3 of the trans 1, 4-structure with delta=127 ppm and delta=137 ppm, two units in the chain structure are mainly TT and TV (trans 1, 4-structure and 1, 2-structure), more TV and CV peak signals are generated in comparative example 1, and a characteristic signal peak delta=116 ppm which is only the obvious 3, 4-structure is generated.

FIG. 3 shows nuclear magnetic resonance spectra of saturated carbon regions of the poly (1, 3-pentadiene) elastomers prepared in example 1, example 14 and comparative example 1 of the present invention ¹³ C NMR) diagram, as can be seen from fig. 3: example 1 and example 1The carbon shift of the saturated carbon region of 4 shows that the 1,4-4,1 (head-to-tail) and 1,4-1,4 (head-to-tail) contents of TT are dominant in the polymer chain structures of examples 1 and 14, wherein the TT of example 1 is the highest in 1,4-4,1 (delta=41 ppm, delta=37 ppm, delta=20 ppm) in the two-chain manner, the content ratio of 1,4-1,4, 1-4,1 of TT is the same, and the 1,4-1,2 and 1, 2-corresponding carbon shifts are substantially absent in example 1, and the polymer chain is clear; whereas example 14 shows corresponding shifts of carbon atoms of CV, TV and VV dias at δ=33 ppm, δ=35 ppm, because the polymer still contains small amounts of 1, 2-and cis-1, 4-structures, the curve of comparative example 1 shows shifts δ=15 ppm and δ=21.5 ppm which occur only with high amounts of VV dias and 3,4-3,4 dias. In addition, no special carbon shift due to side reactions such as branching and cyclization was observed in example 1, example 14 and comparative example 1, indicating that the degree of linearity of the polymer obtained by the present method was very high.

FIG. 4 is a differential calorimetric scan (DSC) of the poly (1, 3-pentadiene) elastomer prepared in example 1, example 7, example 15 and comparative example 1 of the present invention, as can be seen from FIG. 4: as the trans 1, 4-structure content increases, the glass transition temperature Tg decreases continuously, cold crystallization peaks to occur, and as the content increases, it is converted to the melting peak of the semi-crystalline polymer.

FIG. 5 is a Gel Permeation Chromatograph (GPC) diagram of the poly (1, 3-pentadiene) elastomers prepared in example 1, example 7 and comparative example 1 of the present invention, as can be seen from FIG. 5: the molecular weight of the poly-1, 3-pentadiene elastomer shows normal unimodal distribution, the molecular weight distribution of the comparative example 1 without adding organic barium salt or organic sodium salt is narrower, the molecular weight is slightly widened after adding the organic barium salt and the organic sodium salt, but still the molecular weight is in the controllable range of the unimodal distribution, and compared with the molecular weight distribution (> 2.0) of the high trans-structure conjugated diene rubber prepared by a vanadium-based, titanium-based and transition-based (Co) catalytic system, the molecular weight distribution is narrower.

Comparative example 2

Poly (1, 3-pentadiene) elastomer was prepared according to the same organobarium catalyst and alkyllithium polymerization conditions as in example 1, except that: the "catalyst thymol barium BHT" in example 1 was replaced with "sodium t-butoxide (t-Buona)", and the anionic polymerization of 1, 3-pentadiene was carried out in the same ratio as in the system a. The polymer obtained was dried with the solvent removed, and the monomer conversion was 45% by weight.

¹ H NMR analysis shows that the poly-1, 3-pentadiene elastomer has a trans-1, 4-structure content of 46%, a cis-1, 4-structure content of 14%, a 1, 2-structure content of 31% and a small amount of 3, 4-structure, ¹³ c NMR analysis gave a content of about 8.0%.

The molecular weight distribution pdi=1.96 of the obtained polymer has a glass transition temperature tg= -39 ℃, no cold crystallization peak and no obvious melting peak.

The sequence composition of the polymer is shown in Table 1.

Comparative example 3

Poly (1, 3-pentadiene) elastomer was prepared according to the same polymerization conditions as in example 14 using an organosodium catalyst and an alkyllithium, except that: system f "n (SDBS): n (THF): n (n-BuLi) =0.2:20:1" was modified to "0.2:0.1:1 carrying out anionic polymerization of 1, 3-pentadiene. The polymer obtained was dried to remove the solvent, and the monomer conversion was 91% by weight.

¹ H NMR analysis shows that the poly (1, 3-pentadiene) elastomer has a trans-1, 4-structure content of 69%, a cis-1, 4-structure content of 12%, a 1, 2-structure content of 19% and substantially no 3, 4-structure.

The molecular weight distribution pdi=1.32 of the obtained polymer has a glass transition temperature tg= -42 ℃, no cold crystallization peak and no obvious melting peak.

The sequence composition of the polymer is shown in Table 1.

TABLE 1

Note 1: when the Trans-1,4 structure content is more than 80%, the sequence composition and the 1, 2-structure content are not completely corresponding to each other because the three-chain structure TVT overlaps with the 1,4-4, 1-methyl carbon shift peak of TT of two, and the characteristic peak of the 1,2-1,2 content in the saturated carbon region is not obvious.

And (2) injection: including various linking patterns of 1,2-1,2, and head-to-head, head-to-tail, and tail-to-tail of Cis-1,4, and the linking content of 1,4-3, 4.

Remarks: "%" is "mole%".

From the results of examples, comparative examples and Table 1, it can be seen that:

(1) By adopting the preparation method provided by the invention, raw materials of each component are easy to obtain, the reaction rate is high, and the conversion rate is high.

(2) The molecular weight of the poly (1, 3-pentadiene) elastomer prepared by the invention is easy to control, and the number average molecular weight Mn is 4 multiplied by 10 ⁴ g/mol to 5X 10 ⁵ The molecular weight distribution is narrow between g/mol, the molecular weight distribution is far lower than that of 1, 3-pentadiene prepared by coordination polymerization in the range of 1.26-1.88, the microstructure can be efficiently regulated and controlled, the proportion of trans-1, 4-structure is very high, and meanwhile, the content of side propenyl structure is very small; the sequence of the polymer is highly regular, the polymer chain presents a linear structure, and the 1,4-4,1 head-tail linkage mode is dominant.

The preferred embodiments of the present invention have been described in detail above, but the present invention is not limited thereto. Within the scope of the technical idea of the invention, a number of simple variants of the technical solution of the invention are possible, including combinations of the individual technical features in any other suitable way, which simple variants and combinations should likewise be regarded as being disclosed by the invention, all falling within the scope of protection of the invention.

Claims

1. A linear high trans 1, 4-structure content poly 1, 3-pentadiene elastomer characterized in that the poly 1, 3-pentadiene elastomer has a linear structure and the poly 1, 3-pentadiene elastomer comprises 50 to 95 mole% trans 1, 4-structure and the content of 1,4 to 4,1 head-to-tail linkages in the microscopic sequence distribution of the poly 1, 3-pentadiene elastomer is 30 to 80 mole%.

2. The elastomer of claim 1, wherein the poly 1, 3-pentadiene elastomer comprises from 70 to 95 mole percent trans 1, 4-structure; preferably, the poly 1, 3-pentadiene elastomer comprises 79 to 91 mole% of trans 1, 4-structure;

and/or, in the microscopic sequence distribution of the poly-1, 3-pentadiene elastomer, the content of linkages in a 1,4-4,1 head-to-tail manner is 45-80 mole%; preferably, the content of 1,4-4,1 head-to-tail linkages in the microscopic sequence distribution of the poly-1, 3-pentadiene elastomer is 51 to 78 mole percent.

3. The elastomer of claim 1 or 2, wherein the poly 1, 3-pentadiene elastomer further comprises 0-30 mole% of cis 1, 4-structure, 4-25 mole% of 1, 2-structure and 0-10 mole% of 3, 4-structure;

preferably, the poly 1, 3-pentadiene elastomer comprises 0 to 15 mole% of cis 1, 4-structure, 7 to 15 mole% of 1, 2-structure and 0 to 3 mole% of 3, 4-structure.

4. The elastomer according to claim 1 or 2, wherein in the microscopic sequence distribution of the poly-1, 3-pentadiene elastomer:

the total content of head-to-head 1,4-1,4 and tail-to-tail 4,1-4,1 linkages is 10-40 mole%, preferably 10-33 mole%;

and/or, the ratio of head-to-head 1,4-1,4 and tail-to-tail 4,1-4,1 content is 1: (1-5);

and/or the content of the 1,4-1,2 linkage is 5-20 mol%, preferably 5-10 mol%.

5. The elastomer according to any one of claims 1 to 4, wherein the poly-1, 3-pentadiene elastomer has a number average molecular weight of 2 x 10 ⁴ g/mol to 5X 10 ⁵ g/mol；

And/or the molecular weight distribution PDI of the poly 1, 3-pentadiene elastomer is from 1.05 to 2.5, preferably from 1.1 to 1.9;

and/or the glass transition temperature T of the poly-1, 3-pentadiene elastomer _g From-70 ℃ to-30 ℃, preferably from-70 ℃ to-50 ℃;

and/or the melting temperature T of the poly-1, 3-pentadiene elastomer _m Is at 0-90deg.CPreferably 70-90 ℃.

6. A method for preparing a linear high trans-1, 4-structure poly-1, 3-pentadiene elastomer, which is characterized in that the method comprises the following steps:

7. The process according to claim 6, wherein the molar ratio of the total amount of the procatalyst and the cocatalyst to the amount of the initiator is (0.01-100): 1, a step of;

and/or the molar ratio of the polar regulator to the initiator is (0.1-100): 1;

and/or the molar ratio of the 1, 3-pentadiene monomer to the initiator is (200-1000): 1, a step of;

and/or the molar ratio of the cocatalyst to the main catalyst is (0-100): 1, preferably (0-4): 1, a step of;

and/or in step (1), the concentration of 1, 3-pentadiene monomer in the mixed solution is 5 to 20 wt%.

8. The production process according to claim 6, wherein the 1, 3-pentadiene monomer is selected from one or more of cis-1, 3-pentadiene, trans-1, 3-pentadiene, mixed isomerism-1, 3-pentadiene, 2-methyl-1, 3-pentadiene and 2, 3-dimethyl-1, 3-pentadiene;

And/or the organic barium salt is selected from one or more of alkoxy barium salt, cycloalkoxy barium salt, alcohol ether barium salt, alcohol amine barium salt, phenol barium salt and carboxylic acid barium salt;

and/or the organic sodium salt is an alkoxy sodium salt and/or a sodium sulfonate;

and/or the alkyl aluminum is selected from one or more of trimethyl aluminum, triethyl aluminum, tripropyl aluminum, triisobutyl aluminum, triisopropyl aluminum, trioctyl aluminum and methylaluminoxane;

and/or the nonpolar hydrocarbon solvent is selected from one or more of cyclohexane, n-hexane, n-pentane, n-heptane, benzene, hydrogenated oil and extracted oil;

and/or the polarity modifier is selected from one or more of tetrahydrofuran, dioxane, triethylamine, ditetrahydrofuran propane, N-dimethyl tetrahydrofurfuryl amine, tetrahydrofurfuryl alcohol ethyl ether, tetrahydrofurfuryl alcohol butyl ether, pentamethyl diethyl triamine, dipiperidine ethane, triphenylphosphine and carbon disulphide;

and/or, the initiator is an organolithium initiator; preferably, the initiator is selected from one or more of alkyl lithium, aryl lithium, amine lithium, organo lithium chloride and macromolecular active lithium.

9. The production method according to claim 6, wherein the first preheating condition includes: the temperature is 25-80 ℃ and the time is 0.5-3h;

And/or, the second preheating conditions include: the temperature is 50-75 ℃ and the time is 4-5h;

and/or, the polymerization conditions include: the temperature is 0-100deg.C, and the time is 1-24h.

10. A linear high trans 1, 4-structure content poly 1, 3-pentadiene elastomer prepared by the method of any one of claims 6-9.

11. Use of a linear high trans 1, 4-structure content poly-1, 3-pentadiene elastomer as defined in any one of claims 1 to 5 and 10 as a compound in a tire tread and/or sidewall.