An initiator, a double-end functionalized polyconjugated diene liquid rubber and preparation thereof

Abstract

The application discloses an initiator, a double-end functionalized poly-conjugated diene liquid rubber and a preparation method thereof. In the application, alkyl lithium and di(4-piperidyl) substituted alkane are reacted to generate a double nitrogen lithium initiator in situ, and the initiator is used to initiate conjugated diene polymerization to prepare the double-end functionalized liquid rubber. The raw material is easy to obtain, the preparation is simple, the application is suitable for large-scale use, the prepared double-end functionalized liquid rubber has excellent performance, and can be widely applied to the fields of national defense and military industry, automobiles, aerospace, ships, electrical instruments, electromechanical equipment and the like.

Description

Technical Field

[0001] This invention relates to an initiator, a bifunctionalized polyconjugated diene liquid rubber, and the preparation thereof. Background Technology

[0002] Liquid rubber is commonly used in adhesives, modifiers, sealants, circuit board adhesives, rocket propellants, etc. Depending on its application, liquid rubber generally needs to be functionalized. Liquid rubber can be classified according to the type of functional group into hydroxyl-terminated liquid polybutadiene rubber (HTPB), carboxyl-terminated liquid polybutadiene rubber (CTPB), hydroxyl-carboxyl-terminated liquid polybutadiene rubber (HCTPB), epoxidized liquid rubber, amination liquid rubber, hydrogenated liquid rubber, etc. These terminal-functionalized liquid rubbers are mainly synthesized by two methods: free radical method and anionic method. Among them, the anionic method has obvious advantages over the free radical method: (1) the polymer has good monodispersity, with a dispersion index close to 1.0; (2) the polymer molecular weight is controllable, and polymers with different molecular weights can be obtained by controlling the ratio of initiator and monomer; (3) the microstructure is tunable, and the microstructure of the polymer can be controlled by adjusting the initiator concentration, solvent polarity, reaction temperature, etc., to obtain products with different properties; (4) some functional polymers and block polymers can be synthesized conveniently and effectively. Currently, there are two main methods for anionic synthesis of functionalized liquid rubber: one is the dilithium initiator method, which uses lithium metal and dichloroalkane to react to generate organic dilithium compounds. The preparation conditions are harsh, the product yield is low, and it is not suitable for large-scale use. The other is the single lithium initiator method with a protecting group. This method uses protection and deprotection reactions, and the synthesis steps are complicated, which leads to increased costs. Summary of the Invention

[0003] In order to at least partially solve the above-mentioned technical problems, the present invention uses alkyl lithium compounds and di(4-piperidinyl) substituted alkanes as raw materials to prepare an initiator by reacting them in a non-polar solvent. This initiator can initiate the in-situ polymerization of conjugated dienes from both ends to prepare a liquid rubber of a double-ended functionalized polyconjugated diene.

[0004] As a first aspect of the present invention, an initiator is provided, the initiator having the following structure:

[0005]

[0006] Where R is (CH2)n, and the value of n ranges from 3 to 8.

[0007] As a second aspect of the present invention, a method for preparing the initiator is provided, comprising the following steps:

[0008] (1) Dissolve the di(4-piperidinyl)-substituted alkane in a polar solvent to form a solution;

[0009] (2) Add the solution described in step (1), the nonpolar solvent and the alkyl lithium compound to the polymerization reactor in sequence, control the reaction temperature to 25-40°C and react for 10-20 minutes.

[0010] In one or more optional embodiments, the di(4-piperidinyl)substituted alkane is one or more of 1,3-di(4-piperidinyl)propane, 1,3-di(4-piperidinyl)butane, 1,3-di(4-piperidinyl)pentane or 1,3-di(4-piperidinyl)aliphatic hydrocarbons, preferably 1,3-di(4-piperidinyl)propane.

[0011] In one or more alternative embodiments, the 1,3-bis(4-piperidinyl)aliphatic hydrocarbon has an aliphatic hydrocarbon carbon number of 3 to 8 natural numbers.

[0012] In one or more optional embodiments, the alkyl lithium compound is one or more of n-butyllithium, sec-butyllithium or tert-butyllithium, preferably n-butyllithium.

[0013] In one or more alternative embodiments, the molar ratio of the alkyllithium compound to the di(4-piperidinyl)substituted alkane is 2.0:1.0 to 2.4:1.0.

[0014] In one or more alternative embodiments, the polar solvent in step (1) is selected from one or more of toluene, benzene, or tetrahydrofuran.

[0015] In one or more alternative embodiments, the concentration of the solution in step (1) is 0.4 to 2.4 mol / L.

[0016] In one or more alternative embodiments, the nonpolar solvent in step (2) is selected from one or more of hexanes, cyclohexane, or cyclopentane.

[0017] In one or more alternative embodiments, step (2) may further include the addition of a solubilizer, which is a conjugated diene.

[0018] In one or more optional embodiments, the molar ratio of the alkyllithium compound to the solubilizer is 1:0.0001 to 1:50, preferably 1:2 to 1:10.

[0019] In one or more optional embodiments, the conjugated diene is one or more of butadiene, styrene, and isoprene.

[0020] As a third aspect of the invention, there is a bifunctionalized polyconjugated diene liquid rubber, which is polymerized from a conjugated diene monomer under the aforementioned initiator conditions.

[0021] As a fourth aspect of the present invention, a method for preparing a difunctionalized polyconjugated diene liquid rubber is provided, the method comprising: adding a conjugated diene monomer to carry out an in-situ polymerization reaction in the presence of the above-mentioned initiator and nonpolar solvent, then adding a capping agent to cap the monomer, and finally acid washing and solvent removal.

[0022] In one or more alternative embodiments, the capping agent is ethylene oxide, carbon dioxide, or maleic anhydride.

[0023] In one or more alternative embodiments, the molar amount of the capping agent is 3 to 10 times that of the alkyl lithium compound.

[0024] In one or more optional embodiments, the liquid rubber preparation method may further include a modifier, which may be tetrahydrofuran, tetrahydrofurfuryl ether, diethylene glycol dimethyl ether, tetramethylvinyl diamine, pentamethyldiethyltriamine, 1,4-dichlorobenzenebicyclo[2,2,2]octane, or 2,2-bis-(4,4,6-trimethyl-1,3-dichlorohexacyclo).

[0025] In one or more alternative embodiments, the molar amount of the regulator is 0.2 to 4 times that of the alkyl lithium compound.

[0026] In one or more optional embodiments, the conjugated diene monomer is at least one of butadiene, isoprene, and styrene.

[0027] In one or more optional embodiments, the molar ratio of the conjugated diene monomer to the initiator is 20 to 4000:1.

[0028] In one or more optional embodiments, the polymerization reaction temperature is 55–90°C.

[0029] In one or more optional embodiments, the nonpolar solvent is selected from one or more of hexane, cyclohexane, or cyclopentane.

[0030] This invention uses alkyl lithium compounds and di(4-piperidinyl)-substituted alkanes as raw materials to prepare bi-terminal active initiators. Compared with the existing technology of preparing bi-terminal active initiators from metallic lithium in the laboratory, the raw materials are readily available, the preparation process is simple, and it is suitable for large-scale industrial production. The resulting bi-terminal functionalized polyconjugated diene liquid rubber has excellent properties and can be widely used in defense, automotive, aerospace, shipbuilding, electrical instrumentation, electromechanical equipment and other fields. Attached Figure Description

[0031] Figure 1 The infrared curve of the liquid rubber prepared in Example 6 of this invention;

[0032] Figure 2 This is the GPC spectrum of the liquid rubber prepared in Example 6 of the present invention. Detailed Implementation

[0033] The embodiments of the present invention are described in detail below: The embodiments of the present invention are implemented under the premise of the technical solution of the present invention, and detailed implementation methods and processes are given. However, the protection scope of the present invention is not limited to the following embodiments. The process parameters in the following embodiments that do not specify specific conditions are generally in accordance with conventional conditions.

[0034] The endpoints and any values ​​of the ranges disclosed in this invention are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of the various ranges, the endpoint values ​​of the various ranges and individual point values, and individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed in this invention.

[0035] When synthesizing liquid rubber using the bislithium initiator method, the inventors need to react metallic lithium with dihaloalkanes to obtain the bislithium initiator. This method requires harsh conditions and cannot be prepared on a large scale. The inventors implemented the relevant technical solution with reference to patent CN101274972A and found that the method uses protection and deprotection reactions, and the synthesis steps are complicated, which leads to increased costs.

[0036] Since none of the above methods met the inventor's expectations, the inventor conducted further research and developed a method to use alkyllithium and di(4-piperidinyl)-substituted alkanes to react and generate bis(nitrogen) lithium initiator, which is used to initiate the in-situ polymerization of conjugated dienes to prepare bifunctionalized liquid rubber. The raw materials are readily available, the process is simple, and it has the potential for large-scale application.

[0037] The acid washing and desolventizing steps described in this invention employ commonly used reagents and techniques in the field.

[0038] Example 1

[0039] Add 50g of 1,3-bis(4-piperidinyl)propane to a flask, then add 148ml of tetrahydrofuran and dissolve under magnetic stirring to prepare a 1.6mol / L solution.

[0040] The polymerization reactor was solvent cleaned and purged three times with inert gas to maintain a slight positive pressure. 3600g of hexane, 265ml of 1.6mol / L n-butyllithium, 125ml of 1.6mol / L 1,3-bis(4-piperidinyl)propane solution, and 78.3g of butadiene as a solubilizer were added to the 10L polymerization reactor. At the same time, cold water was introduced and the temperature was controlled at 25℃. The reactor was stirred and reacted for 10 minutes.

[0041] Add 600g of butadiene and 35ml of tetrahydrofuran as a regulator. Heat to 65℃, maintaining the reaction temperature below 85℃ for 2 hours. After the reaction, add 30ml of ethylene oxide as a capping agent, heat to 85℃, and react for 0.5 hours. After the reaction, add 100ml of 0.1mol / L hydrochloric acid, then add ethanol to terminate the reaction. Stir for 15 minutes, then cool to 30℃ and discharge to obtain a rubber solution. Pour the rubber solution into a washing tank and wash repeatedly with neutral water until neutral. Allow it to stand and separate into layers. Discard the lower layer of wash water, and allow the upper layer of rubber solution to enter a thin-film evaporator for volatilization, ultimately obtaining liquid rubber.

[0042] Example 2

[0043] Add 75g of 1,3-bis(4-piperidinyl)propane to a flask, then add 222ml of tetrahydrofuran and dissolve under magnetic stirring to prepare a 1.6mol / L solution.

[0044] The polymerization reactor was solvent cleaned and purged three times with inert gas to maintain a slight positive pressure. 3600g of hexane, 420ml of 1.6mol / L n-butyllithium, 200ml of 1.6mol / L 1,3-bis(4-piperidinyl)propane, and 71.2g of butadiene as a solubilizer were added to the 10L polymerization reactor. At the same time, cold water was introduced and the temperature was controlled at 25℃. The reaction was stirred for 15 minutes.

[0045] Add 600g of butadiene and 45ml of tetrahydrofurfuryl ether (THF) as a regulator. Heat to 65℃ and maintain the reaction temperature below 85℃ for 2 hours. After the reaction, add 35ml of ethylene oxide as a capping agent, heat to 85℃, and react for 0.5 hours. After the reaction, add 100ml of 0.1mol / L hydrochloric acid, then add ethanol to terminate the reaction. Stir for 15 minutes, then cool to 30℃ and discharge to obtain a rubber solution. Pour the rubber solution into a washing tank and wash repeatedly with neutral water until neutral. Allow it to stand and separate into layers. Discard the lower layer of wash water, and allow the upper layer of rubber solution to enter a thin-film evaporator for devolatilization, ultimately obtaining liquid rubber.

[0046] Example 3

[0047] Add 50g of 1,3-bis(4-piperidinyl)propane to a flask, then add 148ml of toluene, and dissolve under magnetic stirring to prepare a 1.6mol / L solution.

[0048] The polymerization reactor was solvent cleaned and purged three times with inert gas to maintain a slight positive pressure. 3600g of cyclohexane, 178ml of 1.6mol / L sec-butyllithium, 85ml of 1.6mol / L 1,3-bis(4-piperidinyl)propane solution, and 77.5g of isoprene solubilizer were added to the 10L polymerization reactor. At the same time, cold water was introduced and the temperature was controlled at 30℃. The reaction was stirred for 15 minutes.

[0049] Add 600g of butadiene and 45ml of diethylene glycol dimethyl ether (2g) as a regulator. Heat to 65℃ and maintain the reaction temperature below 85℃ for 2 hours. After the reaction, add 55ml of propylene oxide as a capping agent, heat to 85℃, and react for 0.5 hours. After the reaction, add 100ml of 0.1mol / L hydrochloric acid, then add ethanol to terminate the reaction. Stir for 15 minutes, then cool to 30℃ and discharge to obtain a rubber solution. Pour the rubber solution into a washing tank and wash repeatedly with neutral water until neutral. Allow it to stand and separate into layers. Discard the lower layer of wash water, and allow the upper layer of rubber solution to enter a thin-film evaporator for volatilization, finally obtaining liquid rubber.

[0050] Example 4

[0051] Add 50g of 1,3-bis(4-piperidinyl)propane to a flask, then add 296ml of toluene, and dissolve under magnetic stirring to prepare a 0.8mol / L solution.

[0052] The polymerization reactor was solvent cleaned and purged three times with inert gas to maintain a slight positive pressure. 4000g of cyclopentane, 238ml of 1.6mol / L sec-butyllithium, 226ml of 0.8mol / L 1,3-bis(4-piperidinyl)butane, and 82g of butadiene as a solubilizer were added to the 10L polymerization reactor. At the same time, cold water was introduced and the temperature was controlled at 40℃. The reaction was stirred for 10 minutes.

[0053] Add 800g of butadiene and 45ml of tetrahydrofurfuryl ether (THF) as a regulator. Heat to 65℃ and maintain the reaction temperature below 85℃ for 2 hours. After the reaction, add 65ml of ethylene oxide as a capping agent, heat to 85℃, and react for 0.5 hours. After the reaction, add 100ml of 0.1mol / L hydrochloric acid, then add ethanol to terminate the reaction. Stir for 15 minutes, then cool to 30℃ and discharge to obtain a rubber solution. Pour the rubber solution into a washing tank and wash repeatedly with neutral water until neutral. Allow it to stand and separate into layers. Discard the lower layer of wash water, and allow the upper layer of rubber solution to enter a thin-film evaporator for devolatilization, ultimately obtaining liquid rubber.

[0054] Example 5

[0055] Add 50g of 1,3-bis(4-piperidinyl)propane to a flask, then add 592ml of toluene, and dissolve under magnetic stirring to prepare a 0.4mol / L solution.

[0056] The polymerization reactor was solvent cleaned and purged three times with inert gas to maintain a slight positive pressure. 4000g of cyclohexane, 238ml of 1.6mol / L n-butyllithium, 452ml of 0.4mol / L 1,3-bis(4-piperidinyl)butane, and 54g of butadiene as a solubilizer were added to the 10L polymerization reactor. At the same time, cold water was introduced and the temperature was controlled at 30℃. The reaction was stirred for 20 minutes.

[0057] Add 600g butadiene, 200g styrene, and 45ml tetramethylvinyldiamine as a regulator. Heat to 65℃, maintaining the reaction temperature below 85℃ for 2 hours. After the reaction, add 55ml ethylene oxide as a capping agent, heat to 85℃, and react for 0.5 hours. After the reaction, add 100ml of 0.1mol / L hydrochloric acid, then add ethanol to terminate the reaction. Stir for 15 minutes, then cool to 30℃ and discharge to obtain a rubber solution. Pour the rubber solution into a washing tank and wash repeatedly with neutral water until neutral. Allow it to stand and separate into layers. Discard the lower layer of wash water, and allow the upper layer of rubber solution to enter a thin-film evaporator for devolatilization, ultimately obtaining liquid rubber.

[0058] Example 6

[0059] Add 50g of 1,3-bis(4-piperidinyl)propane to a flask, then add 148ml of toluene, and dissolve under magnetic stirring to prepare a 1.6mol / L solution.

[0060] The polymerization reactor was solvent cleaned and purged three times with inert gas to maintain a slight positive pressure. 3600g of cyclopentane, 178ml of 1.6mol / L n-butyllithium, 85ml of 1.6mol / L 1,3-bis(4-piperidinyl)propane, and 61.5g of butadiene as a solubilizer were added to the 10L polymerization reactor. At the same time, cold water was introduced and the temperature was controlled at 40℃. The reaction was stirred for 10 minutes.

[0061] Add 600g of butadiene and 35ml of 1,4-dichlorobenzenebicyclo[2,2,2]octane as a regulator. Heat to 65℃ and maintain the reaction temperature below 85℃ for 2 hours. After the reaction, add 35ml of ethylene oxide as a capping agent, heat to 85℃, and react for 0.5 hours. After the reaction, add 100ml of 0.1mol / L hydrochloric acid, then add ethanol to terminate the reaction. Stir for 15 minutes, then cool to 30℃ and discharge to obtain a gel. Pour the gel into a washing tank and wash repeatedly with neutral water until neutral. Allow it to stand and separate into layers. Discard the lower layer of washing water, and allow the upper layer of gel to enter a thin-film evaporator for devolatilization. The final liquid rubber is a liquid polybutadiene polymer. Perform infrared scanning on it; the infrared spectrum is shown below. Figure 1 As shown in Table 1, its structure and performance are as follows.

[0062] Example 7

[0063] Add 50g of 1,3-bis(4-piperidinyl)propane to a flask, then add 148ml of toluene, and dissolve under magnetic stirring to prepare a 1.6mol / L solution.

[0064] The polymerization reactor was solvent cleaned and purged three times with inert gas to maintain a slight positive pressure. 3600g of cyclopentane, 178ml of 1.6mol / L n-butyllithium, 85ml of 1.6mol / L 1,3-bis(4-piperidinyl)propane, and 1.14mol of butadiene as a solubilizer were added to the 10L polymerization reactor. At the same time, cold water was introduced and the temperature was controlled at 25℃. The reaction was stirred for 10 minutes.

[0065] Add 600g of butadiene and 35ml of 2,2-bis-(4,4,6-trimethyl-1,3-dichlorohexane) regulator. Heat to 65℃ and maintain the reaction temperature below 85℃ for 2 hours. After the reaction, introduce carbon dioxide as a capping agent to a pressure of 0.4MPa and maintain this pressure while stirring for 0.5 hours. After the reaction is complete, add 100ml of 0.1mol / L hydrochloric acid, followed by ethanol to terminate the reaction. Stir for 15 minutes, then cool to 30℃ and discharge to obtain a rubber solution. Transfer the solution to a washing tank and wash repeatedly with neutral water until neutral. Allow it to stand and separate into layers. Discard the lower layer of wash water and allow the upper layer of rubber solution to enter a thin-film evaporator for volatilization, ultimately obtaining liquid rubber.

[0066] Example 8

[0067] Add 50g of 1,3-bis(4-piperidinyl)propane to a flask, then add 148ml of toluene, and dissolve under magnetic stirring to prepare a 1.6mol / L solution.

[0068] The polymerization reactor was solvent cleaned and purged three times with inert gas to maintain a slight positive pressure. 3600g of cyclopentane, 178ml of 1.6mol / L n-butyllithium, 85ml of 1.6mol / L 1,3-bis(4-piperidinyl)propane, and 77.5g of isoprene were added to the 10L polymerization reactor. At the same time, cold water was introduced and the temperature was controlled at 30℃. The reaction was stirred for 10 minutes.

[0069] Add 600g of butadiene and 35ml of tetrahydrofurfuryl ether (THF) as a regulator. Heat to 65℃ and maintain the reaction temperature below 85℃ for 2 hours. After the reaction, add 60ml of maleic anhydride solution as a capping agent. Heat to 85℃ and react for 0.5 hours. After the reaction, add 100ml of 0.1mol / L hydrochloric acid, then add ethanol to terminate the reaction. Stir for 15 minutes, then cool to 30℃ and discharge to obtain a rubber solution. Pour the rubber solution into a washing tank and wash repeatedly with neutral water until neutral. Allow it to stand and separate into layers. Discard the lower layer of wash water, and allow the upper layer of rubber solution to enter a thin-film evaporator for volatilization, finally obtaining liquid rubber.

[0070] Example 9

[0071] Add 75g of 1,3-bis(4-piperidinyl)propane to a flask, then add 148ml of toluene, and dissolve under magnetic stirring to prepare a 2.4mol / L solution.

[0072] The polymerization reactor was solvent cleaned and purged three times with inert gas to maintain a slight positive pressure. 3600g of cyclohexane, 178ml of 1.6mol / L tert-butyllithium, 85ml of 1.6mol / L 1,3-di(4-piperidinyl)propane, and 98.6g of isoprene were added to the 10L polymerization reactor. At the same time, cold water was introduced and the temperature was controlled at 30℃. The reaction was stirred for 10 minutes.

[0073] Add 600g of butadiene and 35ml of tetrahydrofurfuryl ether (THF) as a regulator. Heat to 65℃ and maintain the reaction temperature below 85℃ for 2 hours. After the reaction, introduce carbon dioxide as a capping agent to a pressure of 0.4MPa and maintain this pressure while stirring for 0.5 hours. After the reaction is complete, add 100ml of 0.1mol / L hydrochloric acid, then add ethanol to terminate the reaction. Stir for 15 minutes, then cool to 30℃ and discharge to obtain a rubber solution. Pour the solution into a washing tank and wash repeatedly with neutral water until neutral. Allow it to stand and separate into layers. Discard the lower layer of wash water, and allow the upper layer of rubber solution to enter a thin-film evaporator for devolatilization, ultimately obtaining liquid rubber.

[0074] Example 10

[0075] Add 50g of 1,3-bis(4-piperidinyl)propane to a flask, then add 148ml of toluene, and dissolve under magnetic stirring to prepare a 1.6mol / L solution.

[0076] The polymerization reactor was solvent cleaned and purged three times with inert gas to maintain a slight positive pressure. 4000g of cyclopentane, 115ml of 1.6mol / L tert-butyllithium, 55ml of 1.6mol / L 1,3-bis(4-piperidinyl)propane, and 87g of isoprene were added to the 10L polymerization reactor. At the same time, cold water was introduced and the temperature was controlled at 30℃. The reaction was stirred for 10 minutes.

[0077] Add 800g of butadiene and 35ml of tetrahydrofurfuryl ether (THF) as a regulator. Heat to 65℃ and maintain the reaction temperature below 85℃ for 2 hours. After the reaction, add 35ml of ethylene oxide as a capping agent, heat to 85℃, and react for 0.5 hours. After the reaction, add 100ml of 0.1mol / L hydrochloric acid, then add ethanol to terminate the reaction. Stir for 15 minutes, then cool to 30℃ and discharge to obtain a rubber solution. Pour the rubber solution into a washing tank and wash repeatedly with neutral water until neutral. Allow it to stand and separate into layers. Discard the lower layer of wash water, and allow the upper layer of rubber solution to enter a thin-film evaporator for devolatilization, ultimately obtaining liquid rubber.

[0078] Example 11

[0079] Add 50g of 1,3-bis(4-piperidinyl)propane to a flask, then add 148ml of toluene, and dissolve under magnetic stirring to prepare a 1.6mol / L solution.

[0080] The polymerization reactor was solvent cleaned and purged three times with inert gas to maintain a slight positive pressure. 4000g of cyclopentane, 115ml of 1.6mol / L tert-butyllithium, 55ml of 1.6mol / L 1,3-bis(4-piperidinyl)propane, and 59.8g of isoprene were added to the 10L polymerization reactor. At the same time, cold water was introduced and the temperature was controlled at 30℃. The reaction was stirred for 10 minutes.

[0081] Add 800g of butadiene and 35ml of tetrahydrofurfuryl ether (THF) as a regulator. Heat to 65℃ and maintain the reaction temperature below 85℃ for 2 hours. After the reaction, add 35ml of ethylene oxide as a capping agent, heat to 85℃, and react for 0.5 hours. After the reaction, add 100ml of 0.1mol / L hydrochloric acid, then add ethanol to terminate the reaction. Stir for 15 minutes, then cool to 30℃ and discharge to obtain a rubber solution. Pour the rubber solution into a washing tank and wash repeatedly with neutral water until neutral. Allow it to stand and separate into layers. Discard the lower layer of wash water, and allow the upper layer of rubber solution to enter a thin-film evaporator for devolatilization, ultimately obtaining liquid rubber.

[0082] Example 12

[0083] Add 50g of 1,3-bis(4-piperidinyl)propane to a flask, then add 148ml of toluene, and dissolve under magnetic stirring to prepare a 1.6mol / L solution.

[0084] The polymerization reactor was solvent cleaned and purged three times with inert gas to maintain a slight positive pressure. 4000g of cyclopentane, 115ml of 1.6mol / L n-butyllithium, 55ml of 1.6mol / L 1,3-bis(4-piperidinyl)propane, and 25.9g of butadiene as a solubilizer were added to the 10L polymerization reactor. At the same time, cold water was introduced and the temperature was controlled at 30℃. The reaction was stirred for 10 minutes.

[0085] Add 600g of butadiene and 35ml of tetrahydrofuran as a regulator. Heat to 65℃ and maintain the reaction temperature below 85℃ for 2 hours. After the reaction, add 35ml of ethylene oxide as a capping agent, heat to 85℃, and react for 0.5 hours. After the reaction, add 100ml of 0.1mol / L hydrochloric acid, then add ethanol to terminate the reaction. Stir for 15 minutes, then cool to 30℃ and discharge to obtain a rubber solution. Pour the rubber solution into a washing tank and wash repeatedly with neutral water until neutral. Allow it to stand and separate into layers. Discard the lower layer of wash water, and allow the upper layer of rubber solution to enter a thin-film evaporator for volatilization, finally obtaining liquid rubber.

[0086] Example 13

[0087] Add 50g of 1,3-bis(4-piperidinyl)propane to a flask, then add 148ml of toluene, and dissolve under magnetic stirring to prepare a 1.6mol / L solution.

[0088] The polymerization reactor was solvent cleaned and purged three times with inert gas to maintain a slight positive pressure. 4000g of cyclopentane, 115ml of 1.6mol / L n-butyllithium, 55ml of 1.6mol / L 1,3-bis(4-piperidinyl)propane, and 12.96g of butadiene as a solubilizer were added to the 10L polymerization reactor. At the same time, cold water was introduced and the temperature was controlled at 30℃. The reactor was stirred and reacted for 10 minutes.

[0089] Add 600g of butadiene and 35ml of tetrahydrofuran as a regulator. Heat to 65℃, maintaining the reaction temperature below 85℃ for 2 hours. After the reaction, add 35ml of ethylene oxide as a capping agent, heat to 85℃, and react for 0.5 hours. After the reaction, add 100ml of 0.1mol / L hydrochloric acid, then add ethanol to terminate the reaction. Stir for 15 minutes, then cool to 30℃ and discharge to obtain a rubber solution. Pour the rubber solution into a washing tank and wash repeatedly with neutral water until neutral. Allow it to stand and separate into layers. Discard the lower layer of wash water, and allow the upper layer of rubber solution to enter a thin-film evaporator for volatilization, ultimately obtaining liquid rubber.

[0090] Example 14

[0091] Add 50g of 1,3-bis(4-piperidinyl)propane to a flask, then add 148ml of toluene, and dissolve under magnetic stirring to prepare a 1.6mol / L solution.

[0092] The polymerization reactor was solvent cleaned and purged three times with inert gas to maintain a slight positive pressure. 4000g of cyclopentane, 115ml of 1.6mol / L n-butyllithium, 55ml of 1.6mol / L 1,3-di(4-piperidinyl)propane, and 8.16g of isoprene were added to the 10L polymerization reactor. At the same time, cold water was introduced and the temperature was controlled at 30℃. The reaction was stirred for 10 minutes.

[0093] Add 600g butadiene, 200g styrene, and 35ml of 2,2-bis-(4,4,6-trimethyl-1,3-dichlorohexane) regulator. Heat to 65℃ and maintain the reaction temperature below 85℃ for 2 hours. After the reaction, add 35ml of ethylene oxide end-capping agent and heat to 85℃ for 0.5 hours. After the reaction, add 100ml of 0.1mol / L hydrochloric acid, then add ethanol to terminate the reaction. Stir for 15 minutes, then cool to 30℃ and discharge to obtain a rubber solution. Pour the rubber solution into a washing tank and wash repeatedly with neutral water until neutral. Allow it to stand and separate into layers. Discard the lower layer of wash water, and allow the upper layer of rubber solution to enter a thin-film evaporator for volatilization, ultimately obtaining liquid rubber.

[0094] Example 15

[0095] Add 50g of 1,3-bis(4-piperidinyl)propane to a flask, then add 148ml of toluene, and dissolve under magnetic stirring to prepare a 1.6mol / L solution.

[0096] The polymerization reactor was solvent cleaned and purged three times with inert gas to maintain a slight positive pressure. 4000g of cyclopentane, 238ml of 1.6mol / L n-butyllithium, 113ml of 1.6mol / L co-initiator 1,3-bis(4-piperidinyl)propane, and 5.1g of solubilizer butadiene were added to the 10L polymerization reactor. At the same time, cold water was introduced and the temperature was controlled at 30℃. The reactor was stirred and reacted for 10 minutes.

[0097] Add 600g butadiene, 200g styrene, and 45ml pentamethyldiethyltriamine as a regulator. Heat to 65℃ and maintain the reaction temperature below 85℃ for 2 hours. After the reaction, add 55ml ethylene oxide as a capping agent, heat to 85℃, and react for 0.5 hours. After the reaction, add 100ml of 0.1mol / L hydrochloric acid, then add ethanol to terminate the reaction. Stir for 15 minutes, then cool to 30℃ and discharge to obtain a rubber solution. Pour the rubber solution into a washing tank and wash repeatedly with neutral water until neutral. Allow it to stand and separate into layers. Discard the lower layer of wash water, and allow the upper layer of rubber solution to enter a thin-film evaporator for devolatilization, ultimately obtaining liquid rubber.

[0098] Example 16

[0099] Add 50g of 1,3-bis(4-piperidinyl)propane to a flask, then add 148ml of toluene, and dissolve under magnetic stirring to prepare a 1.6mol / L solution.

[0100] The polymerization reactor was solvent cleaned and purged three times with inert gas to maintain a slight positive pressure. 4000g of cyclopentane, 115ml of 1.6mol / L n-butyllithium, 55ml of 1.6mol / L co-initiator 1,3-bis(1-methylvinyl)benzene, and 1.36g of isoprene solubilizer were added to the 10L polymerization reactor. At the same time, cold water was introduced and the temperature was controlled at 30℃. The reactor was stirred and reacted for 10 minutes.

[0101] Add 600g butadiene, 200g styrene, and 35ml of 2,2-bis-(4,4,6-trimethyl-1,3-dichlorohexane) regulator. Heat to 65℃ and maintain the reaction temperature below 85℃ for 2 hours. After the reaction, add 35ml of ethylene oxide end-capping agent and heat to 85℃ for 0.5 hours. After the reaction, add 100ml of 0.1mol / L hydrochloric acid, then add ethanol to terminate the reaction. Stir for 15 minutes, then cool to 30℃ and discharge to obtain a rubber solution. Pour the rubber solution into a washing tank and wash repeatedly with neutral water until neutral. Allow it to stand and separate into layers. Discard the lower layer of wash water, and allow the upper layer of rubber solution to enter a thin-film evaporator for volatilization, ultimately obtaining liquid rubber.

[0102] Example 17

[0103] Add 50g of 1,3-bis(4-piperidinyl)propane to a flask, then add 148ml of toluene, and dissolve under magnetic stirring to prepare a 1.6mol / L solution.

[0104] The polymerization reactor was cleaned with solvent and purged three times with inert gas to maintain a slight positive pressure. 4000g of cyclopentane, 238ml of 1.6mol / L n-butyllithium, and 113ml of 1.6mol / L 1,3-bis(4-piperidinyl)propane were added to the 10L polymerization reactor. At the same time, cold water was introduced and the temperature was controlled at 30℃. The reaction was stirred for 10 minutes.

[0105] Add 600g butadiene, 200g styrene, and 45ml tetramethylvinyldiamine as a regulator. Heat to 65℃, maintaining the reaction temperature below 85℃ for 2 hours. After the reaction, add 55ml ethylene oxide as a capping agent, heat to 85℃, and react for 0.5 hours. After the reaction, add 100ml of 0.1mol / L hydrochloric acid, then add ethanol to terminate the reaction. Stir for 15 minutes, then cool to 30℃ and discharge to obtain a rubber solution. Pour the rubber solution into a washing tank and wash repeatedly with neutral water until neutral. Allow it to stand and separate into layers. Discard the lower layer of wash water, and allow the upper layer of rubber solution to enter a thin-film evaporator for devolatilization, ultimately obtaining liquid rubber.

[0106] Test Example 1

[0107] The molecular weight and molecular weight distribution of the liquid rubbers prepared in Examples 1-17 were determined by gel permeation chromatography (GPC). The hydroxyl functional groups and functionality were tested according to GB1327-91 standard, and the carboxyl functional groups and functionality were tested according to GB / T10338-1989 standard. The results are shown in Table 1. The infrared spectrum of the hydroxyl-terminated liquid rubber prepared in Example 6 is shown below. Figure 1 As shown, Figure 1 The absorption peak between 3000-3500 nm is the hydroxyl absorption peak. The analytical chromatogram of the hydroxyl-terminated liquid rubber GPC prepared in Example 6 is shown below. Figure 2 As shown, analysis Figure 2 It can be seen that the number-average molecular weight of the hydroxyl-terminated liquid rubber prepared in the embodiments of the present invention is 4326, and the molecular weight distribution is 1.36.

[0108] Table 1. Properties of the liquid rubbers obtained in Examples 1-17

[0109] Example 1 3140 1.24 hydroxyl 1.88 Example 2 2060 1.09 hydroxyl 1.98 Example 3 4852 1.37 hydroxyl 1.79 Example 4 4430 1.37 hydroxyl 1.79 Example 5 4245 1.36 hydroxyl 1.84 Example 6 4326 1.36 hydroxyl 1.89 Example 7 4852 1.34 hydroxyl 1.89 Example 8 4345 1.28 carboxyl 1.75 Example 9 4250 1.26 carboxyl 1.78 Example 10 9200 1.69 hydroxyl 1.64 Example 11 14500 2.18 hydroxyl 1.64 Example 12 13500 2.45 hydroxyl 0.85 Example 13 24850 2.87 hydroxyl 0.43 Example 14 54500 3.35 hydroxyl 0.25 Example 15 100800 2.49 hydroxyl 0.47 Example 16 154800 3.26 hydroxyl 0.55 Example 17 175000 3.52 hydroxyl 0.15

[0110] Wherein, functionality (f) = number of moles of functional groups per gram of polymer / number of moles of polymer per gram

[0111] As shown in Table 1, the liquid rubber prepared in the embodiments of the present invention meets the requirements for double-ended functionalized liquid rubber in terms of molecular weight, molecular weight distribution, and functionality. Furthermore, as can be seen from Examples 1-9 and Examples 10-17, the present invention can also obtain double-ended functionalized liquid rubber with molecular weight, molecular weight distribution, and functionality closer to the theoretical design values ​​by adjusting the amount of solubilizer.

[0112] Although specific embodiments of the invention have been described in detail, those skilled in the art will understand that various modifications and substitutions can be made to those details based on all the teachings disclosed, and all such changes are within the scope of protection of this invention. The full scope of this invention is given by the appended claims and any equivalents thereof.

Claims

1. A process for preparing a di-end-functionalized polyconjugated diene liquid rubber, characterized in that, The method includes: (1) Dissolve the di(4-piperidinyl)-substituted alkane in a polar solvent to form a solution; (2) Add nonpolar solvent, solution obtained in step (1) and alkyl lithium compound to polymerization reactor in sequence, add solubilizer, control reaction temperature at 25~40℃, and react for 10~20 minutes; (3) Add conjugated diene monomer and regulator to carry out in-situ polymerization reaction, the polymerization reaction temperature is 55~90℃; then add end-capping agent to end-cap, and finally acid wash and solvent removal; In step (1), the di(4-piperidinyl)substituted alkane is a 1,3-di(4-piperidinyl) aliphatic hydrocarbon, and the number of carbon atoms in the 1,3-di(4-piperidinyl) aliphatic hydrocarbon is a natural number from 3 to 8. In step (2), the alkyl lithium compound is one or more of n-butyllithium, sec-butyllithium, or tert-butyllithium, and the molar ratio of the alkyl lithium compound to the di(4-piperidinyl)substituted alkane is 2.0:1.0 to 2.4:1.0; the solubilizer is a conjugated diene, and the molar ratio of the alkyl lithium compound to the solubilizer is 1:0.0001 to 1:50; In step (3), the molar amount of the regulator is 0.2 to 4 times that of the alkyl lithium compound; the end-capping agent is ethylene oxide, carbon dioxide or maleic anhydride; and the molar amount of the end-capping agent is 3 to 10 times that of the alkyl lithium compound.

2. The method of claim 1, wherein, In step (1), the di(4-piperidinyl)substituted alkane is one of 1,3-di(4-piperidinyl)propane, 1,3-di(4-piperidinyl)butane or 1,3-di(4-piperidinyl)pentane.

3. The method of claim 1, wherein, In step (2), the alkyl lithium compound is n-butyllithium.

4. The method of claim 1, wherein, In step (1), the polar solvent is selected from one or more of toluene, benzene or tetrahydrofuran.

5. The method of claim 1, wherein, The concentration of the solution in step (1) is 0.4~2.4 mol / l.

6. The method of claim 1, wherein, In step (2), the nonpolar solvent is selected from one or more of hexanes, cyclohexane, or cyclopentane.

7. The method of claim 1, wherein, In step (2), the molar ratio of the alkyl lithium compound to the solubilizer is 1:2 to 1:

10.

8. The method of claim 1, wherein, In step (2), the solubilizer is one or more of butadiene, styrene, and isoprene.

9. The method as described in claim 1, characterized in that, In step (3), the regulator is tetrahydrofuran, tetrahydrofurfuryl ether, diethylene glycol dimethyl ether, tetramethylvinyl diamine, pentamethyldiethyltriamine, 1,4-dichlorobenzenebicyclo[2,2,2]octane or 2,2-bis-(4,4,6-trimethyl-1,3-dichlorohexacyclo).

10. The method as described in claim 1, characterized in that, In step (3), the conjugated diene monomer is at least one of butadiene, isoprene or styrene.

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