A conjugated diene polymer-based composite and a method for preparing the same

Abstract

The present application belongs to the field of olefin polymerization, and relates to a conjugated diene polymer-based composite and a preparation method thereof. The content of cis-1,4-structure of conjugated diene structural units in a polymer molecular chain is 40% to 70%, the content of 1,2-structure is 20% to 50%, the content of trans-1,4-structure is 5% to 20%, the mass content of SiO2 is 0.5% to 40%, and the SiO2 is uniformly dispersed in the composite. The prepared polybutadiene-based composite provided by the present application has higher thermal stability and green rubber tensile strength, and has improved wet skid resistance, reduced rolling resistance and heat generation, and is beneficial to manufacturing high-performance tires.

Description

TECHNICAL FIELD

[0001] The present application belongs to the field of olefin polymerization, and relates to a conjugated diene polymer-based composite and an in-situ preparation method thereof, in particular to a conjugated diene polymer-based composite and a preparation method of the poly-conjugated diene-based composite. BACKGROUND

[0002] Rubber is widely used in the fields of national economy and military and national defense due to its unique high elasticity. However, the mechanical properties, fatigue resistance and wear resistance of un-reinforced rubber are relatively poor, and it is usually necessary to add fillers having a reinforcing effect to rubber to improve its practical value. Since the surface of silica is rich in hydroxyl groups, the silica has relatively high polarity and poor compatibility with rubber (such as polybutadiene rubber, polyisoprene rubber, styrene-butadiene rubber, etc.), and has serious agglomeration in rubber. The agglomerates will become stress concentration points of the material, leading to premature damage of the material during use. Direct addition of silica to rubber results in poor reinforcing effect. In order to improve the dispersibility of silica in the rubber matrix and the interfacial bonding strength between silica and rubber, there are usually three methods: (1) adding a silane coupling agent during mixing of silica and rubber; (2) surface modification of silica by using a silane coupling agent; and (3) surface modification of silica by grafting a polymer chain. When mixing with a coupling agent, the chemical bonds generated during vulcanization link silica to rubber macromolecules through the coupling agent, but there are problems of residue and migration of small molecule coupling agents in the system, and the increase of the amount of the coupling agent will lead to the problem of reduced strength of solution styrene-butadiene rubber (SSBR) vulcanizate, and the use of a silane coupling agent (such as Si69) during operation will release a large amount of ethanol, which is not conducive to environmental protection. See: Synthetic Rubber Industry, 2014, 37(2): 144-148; Journal of Qingdao University of Science and Technology, 2004, 25(2): 160-162. Surface modification of silica by using a coupling agent can introduce long-chain alkyl groups, reactive groups such as C=C double bonds, epoxy groups, mercapto groups and amide groups, which can improve the dispersibility of silica and reduce the agglomeration phenomenon. In the subsequent vulcanization process, the silica particles can exist in the rubber in the form of crosslinking centers, thereby improving the dispersibility of silica in the rubber and improving the dynamic mechanical properties of the vulcanizate. See: Polym. Adv. Tech., 2004, 15: 400-408; Composite Interface, 2013, 20: 1-12; Chinese J. Chem. Eng., 2006, 14(1): 93-98. Surface modification of silica by using a coupling agent can make the surface of silica contain an initiation group, and initiate polymerization on the surface of the modified particles to prepare a polyisoprene grafted modified silica hybrid material, which is used to regulate the reinforcing performance of rubber. See: Eur. Polym. J., 2013, 49(10): 3078-3088.

[0003] In the prior art, silica is blended with rubber by using a blending technique, and a silane coupling agent is added to chemically bond the silica and rubber during subsequent vulcanization to improve the dispersion of carbon dioxide and reinforcing effect. Alternatively, the surface of the silica is modified to introduce long-chain alkyl groups, reactive groups or polymer chains, which is a complex process. SUMMARY

[0004] One of the objects of the present application is to provide a conjugated diene polymer-based composite in which the content of cis-1,4-structure of conjugated diene structural units is 40 to 70%, the content of 1,2-structure is 20 to 50%, the content of trans-1,4-structure is 2 to 20%, the mass content of SiO2 is 0.5 to 40%, and the SiO2 is uniformly dispersed in the composite.

[0005] Preferably, the content of cis-1,4-structure in the polymer molecular chain is 43 to 64%, the content of 1,2-structure is 24 to 48%, the content of trans-1,4-structure is 3 to 16%, the mass content of SiO2 is 1 to 35%, and the SiO2 is uniformly dispersed in the composite.

[0006] Another object of the present application is to provide a method for preparing a conjugated diene polymer-based composite, which uses a conjugated diene polymerization system comprising a cobalt compound (A), an organic aluminum compound (B), a silicon-containing compound (C), a conjugated diene monomer (D) and a solvent (E).

[0007] The method comprises the following steps: contacting and mixing the cobalt compound (A), the organic aluminum compound (B), the silicon-containing compound (C), the conjugated diene monomer (D) and the solvent (E) to perform a polymerization reaction, and after the reaction is completed, the polymerization product is precipitated and dried to obtain the conjugated diene polymer-based composite.

[0008] According to a preferred embodiment of the present application, the molar ratio of the cobalt compound (A) to the conjugated diene monomer (D) is (1 x 10 -6 ~ 6 x 10 -4 ): 1, preferably (5 x 10 -5 ~ 5 x 10 -4 ): 1, and more preferably (8 x 10 -5 ~ 4 x 10 -4 ): 1; and the molar ratio of the organic aluminum compound (B) to the conjugated diene monomer (D) is (6 x 10 -4 ~ 9.0 x 10 -3 ): 1, preferably (8 x 10 -4 ~ 8.0 x 10 -3 ): 1, and more preferably (9 x 10 -4~ 7.0 x 10 -3 ): 1 ; the mass ratio of the silicon-containing compound (C) to the conjugated diene monomer (D) is (0.1 x 10 -2 ~ 8 x 10 -2 ): 1, preferably (0.2 x 10 -2 ~ 7 x 10 -2 ): 1, more preferably (0.4 x 10 -2 ~ 6 x 10 -2 ): 1 ; the mass-volume ratio of the conjugated diene monomer (D) to the monomers and solvent (D+E) is 40-560 g: 1 L, preferably 50-550 g: 1 L, more preferably 60-540 g: 1 L.

[0009] According to a preferred embodiment of the present application, the cobalt compound (A) is selected from at least one compound of organic acid salts of cobalt and / or cobalt acetylacetonate, preferably selected from at least one compound of cobalt diacetylacetonate, cobalt triacetylacetonate, cobalt naphthenate, cobalt neodecanoate, cobalt benzoate, cobalt stearate, cobalt octanoate, cobalt iso-octanoate, cobalt oleate and cobalt linoleate; more preferably selected from at least one compound of cobalt naphthenate, cobalt octanoate, cobalt neodecanoate and cobalt iso-octanoate.

[0010] According to a preferred embodiment of the present application, the organoaluminum compound (B) is a compound of the general formula AlR 1 3 and / or the general formula AlHR 2 2, R 1 and R 2 are each independently a C1-C6 alkyl, preferably selected from at least one compound of ethyl, propyl or butyl; the organoaluminum compound (B) is preferably selected from at least one compound of trimethylaluminum, triethylaluminum, tripropylaluminum, tributylaluminum, triisobutylaluminum, triamylaluminum, trihexylaluminum, diethylaluminum hydride, dibutylaluminum hydride and diisobutylaluminum hydride; more preferably selected from at least one compound of triethylaluminum, triisobutylaluminum, diethylaluminum hydride, dibutylaluminum hydride and diisobutylaluminum hydride.

[0011] According to a preferred embodiment of the present application, the silicon-containing compound (C) is selected from at least one compound of polysiloxane and / or silicon dioxide.

[0012] Further, the polysiloxane is a silicone oil (linear polysiloxane), preferably selected from at least one compound of methyl silicone oil, ethyl silicone oil, phenyl silicone oil, methyl hydrogen-containing silicone oil, methyl phenyl silicone oil, methyl chlorophenyl silicone oil, methyl ethoxy silicone oil, methyl trifluoropropyl silicone oil, methyl vinyl silicone oil, methyl hydroxyl silicone oil, ethyl hydrogen-containing silicone oil, hydroxyl hydrogen-containing silicone oil and cyano-containing silicone oil; more preferably selected from at least one compound of methyl silicone oil, ethyl silicone oil, methyl hydrogen-containing silicone oil, ethyl hydrogen-containing silicone oil and hydroxyl hydrogen-containing silicone oil.

[0013] Further, the silica is a precipitated silica or a fumed silica; preferably, the specific surface area of the silica is 150-450 m 2 / g, more preferably 175-350 m 2 / g; and the surface double bond content is preferably 0.01-300 mmol / kg, more preferably 0.05-260 mmol / kg.

[0014] According to a preferred embodiment of the present application, the conjugated diene monomer (D) is selected from at least one of butadiene, isoprene, 2-methyl-1,3-pentadiene, 2,4-hexadiene, styrene and methylstyrene, preferably at least one compound of butadiene, isoprene, styrene and methylstyrene, more preferably at least one compound of butadiene, isoprene and styrene.

[0015] According to a preferred embodiment of the present application, the solvent (E) is a hydrocarbon compound, which is preferably at least one of aliphatic hydrocarbons, alicyclic hydrocarbons and aromatic hydrocarbons, more preferably at least one compound selected from butane, pentane, hexane, cyclohexane, heptane, octane, methylcyclohexane, benzene, toluene, xylene and mesitylene, further preferably at least one compound selected from butane, pentane, hexane, cyclohexane and toluene.

[0016] In the present application, the components in the catalyst are mixed with the conjugated diene monomer / olefin solvent solution at a certain temperature in a certain order to carry out the reaction. The feeding order has certain influence on the catalyst activity and catalytic effect. The mixing mode is selected from any one of C-(A+E)-(D+E)-(B+E), (C+A+E)-(D+E)-(B+E), C-(D+E)-(A+E)-(B+E), C-(D+E)-(B+E)-(A+E), (D+E)-C-(A+E)-(B+E), (D+E)-C-(B+E)-(A+E), (D+E)-(A+E)-C-(B+E) and (D+E)-(A+E)-B-C.

[0017] According to the preparation method provided by the present application, preferably, the reaction temperature of the polymerization reaction is -60-120°C, more preferably -30-110°C, further preferably 0-105°C; the reaction time is 30 min-30 h, more preferably 1 h-20 h, further preferably 30 min-3 h. When the polymerization reaction temperature is low, the polymerization time can be prolonged; when the polymerization reaction temperature is high, the polymerization time can be shortened.

[0018] The copolymerization reaction of the present application is carried out under the protection of inert gas, preferably under the protection of nitrogen. When the polymerization reaction is finished, the reaction can be terminated by using water, alcohol, phenol and other compounds as the terminating agent; and the terminating agent can also be added with carboxylic acid, amine compound, ester compound and other additives.

[0019] The coordination polymerization reaction can be carried out in a single polymerization reactor device, a series of polymerization reactor devices, or a tubular reactor, and can be operated in a batch polymerization or continuous polymerization mode.

[0020] The present application also provides a conjugated diene polymer-based composite prepared by the above method.

[0021] The present application provides the following beneficial effects:

[0022] (1) The conjugated diene polymer-based composite is directly prepared by using the in-situ polymerization method, and the SiO2 is uniformly dispersed in the composite, thereby eliminating the process of adding silane coupling agent during the mixing and processing of rubber and silica.

[0023] (2) The microstructure and composition content can be adjusted within a certain range, wherein the content of cis-1,4-structure in the polybutadiene structural unit is 40% to 70%, the content of 1,2-structure is 20% to 50%, the content of trans-1,4-structure is 2% to 20%, and the mass content of SiO2 is 0.5% to 40%.

[0024] (3) Compared with the commercial product BR9000 of high-cis polybutadiene, the prepared polybutadiene-based composite has higher thermal stability and green rubber tensile strength, and has improved wet skid resistance, reduced rolling resistance and heat generation, which is beneficial to the manufacture of high-performance tires.

[0025] Other features and advantages of the present application will be described in detail in the following specific embodiments. DETAILED DESCRIPTION

[0026] The preferred embodiments of the present application will be described in more detail below. Although the preferred embodiments of the present application are described below, it should be understood that the present application can be implemented in various forms and should not be limited by the embodiments described herein.

[0027] The characterization methods involved in the present application are as follows:

[0028] (1) The infrared spectrum of the soluble part is measured by using the Nicolet Fourier transform infrared spectrometer Nicolet 6700 (FTIR), and the scanning range is set to 400-2000 cm -1 , and the microstructure content of the polymer is calculated.

[0029] (2) The dispersion of silica in the composite was observed using an Olympus-BX51 phase contrast microscope (PCM).

[0030] (3) The dynamic mechanical properties of the hybrid material were tested using a TA-Q800 DMA dynamic mechanical analyzer, with the test conditions being film stretching, a temperature range of -130°C to 100°C, and a temperature rise rate of 10°C / min.

[0031] (4) Stress-strain tensile tests were performed using an Instron-3345 universal tensile testing machine in accordance with the national standard GB / T 528-2009.

[0032] Example 1

[0033] Under nitrogen protection, 489 mg of nano-SiO2 (specific surface area of 339 m 2 / g, surface double bond content of 0.5 mmol / kg) and a hexane solution of cobalt neodecanoate ([Co]=0.016 mol / L) were added to a dry polymerization reactor, mixed at 50°C for 1 h, and then a butadiene / hexane solution and a triisobutyl aluminum solution were added, with the mass ratio of SiO2 to monomer being 2.5%, the molar ratio of cobalt to monomer being 1×10 -4 :1, the molar ratio of aluminum to monomer being 1.0×10 -3 :1, and the mass-volume ratio of monomer (D) to monomer and solvent (D+E) being 131 g:1 L. After polymerization at 50°C for 3 h, a hexane solution containing 1 wt% of 3-(3,5-di-tert-butyl-4-hydroxyphenyl) propyl octadecylate was added to the polymerization reactor to terminate the reaction, and the product was washed and dried to constant weight in a vacuum oven at 40°C. In the obtained polybutadiene / silica composite, the mass content of polybutadiene was 97.3%, and the mass content of silica was 2.7%, which was uniformly dispersed in the composite. In addition, the content of cis-1,4 in the polybutadiene structural unit was 58.1%, the content of trans-1,4 was 14.5%, and the content of 1,2 was 27.4%.

[0034] The initial decomposition temperature of the polybutadiene / silica composite in air was 429.9°C; the tensile strength was 1.02 MPa, and the elongation at break was 161%; the tan δ value at 0°C was 0.16, and the tan δ value at 60°C was 0.05.

[0035] Compared with Comparative Example 1 (existing cis-butadiene rubber industrial product BR9000), the initial decomposition temperature was increased by 4.6°C, the thermal stability was improved; the tensile strength was increased by 6.3 times, effectively improving the physical and mechanical properties; the tan δ value at 0°C was increased by 3.7 times, and the tan δ value at 60°C was reduced by 4.7 times, effectively improving the wet skid resistance of the rubber and reducing the rolling resistance and heat generation.

[0036] Example 2

[0037] The catalyst and polymerization process were the same as in Example 1, except that the cobalt compound A was cobalt isooctoate, 259 mg of nano-SiO2 (specific surface area 310 m 2 / g, surface double bond content 2.5 mmol / kg) was added to the dry polymerization reactor, so that the mass ratio of SiO2 to monomer was 5%, the molar ratio of cobalt to monomer was 1 x 10 -4 :1, and the molar ratio of aluminum to monomer was 2.5 x 10 -3 :1. In the resulting polybutadiene / silica composite, the polybutadiene mass content was 83.4%, the silica mass content was 16.6%, and the silica was uniformly dispersed in the composite. In addition, the content of cis-1,4 structure in the polybutadiene structural units was 60.6%, the content of trans-1,4 structure was 15.3%, and the content of 1,2 was 24.6%.

[0038] The initial thermal decomposition temperature of the polybutadiene / silica composite in air was 428.6°C.

[0039] Compared with Comparative Example 1, the initial thermal decomposition temperature was increased by 3.3°C, and the thermal stability was improved.

[0040] Example 3

[0041] The catalyst and polymerization process were the same as in Example 1, except that the cobalt compound A was cobalt isooctoate, 259 mg of nano-SiO2 (specific surface area 317 m 2 / g, surface double bond content 5 mmol / kg) was added to the dry polymerization reactor, so that the mass ratio of SiO2 to monomer was 5%, the molar ratio of cobalt to monomer was 4 x 10 -4 :1, and the molar ratio of aluminum to monomer was 6 x 10 -3 :1. In the resulting polybutadiene / silica composite, the polybutadiene mass content was 88.9%, the silica mass content was 11.1%, and the silica was uniformly dispersed in the composite. In addition, the content of cis-1,4 structure in the polybutadiene structural units was 54.6%, the content of trans-1,4 structure was 8.1%, and the content of 1,2 was 37.3%.

[0042] The initial thermal decomposition temperature of the polybutadiene / silica composite in air was 433.7°C.

[0043] Compared with Comparative Example 1, the initial thermal decomposition temperature was increased by 8.4°C, and the thermal stability was improved.

[0044] Example 4

[0045] The catalyst and polymerization process are the same as in Example 1, except that cobalt compound A is cobalt isooctanoate, and 259 mg of SiO2 (with a specific surface area of ​​317 m²) is added to a dry polymerization reactor. 2 / g, surface double bond content is 5mmol / kg), silicon to monomer mass ratio is 5%, cobalt to monomer molar ratio is 2×10 -4 :1, The molar ratio of triisobutylaluminum to monomer is 3×10 -3 1. The feeding sequence is as follows: first add SiO2, then add a hexane solution of cobalt isooctanoate. The SiO2 and cobalt isooctanoate hexane solution are pre-mixed at 30°C for 0.5 h. Next, add a hexane solution of Bd, and finally add triisobutylaluminum. In the resulting polybutadiene / silica composite, the mass content of polybutadiene is 90.6%, and the mass content of silica is 9.4%, both uniformly dispersed in the composite. Furthermore, the content of cis-1,4-polybutadiene structural units is 43.8%, trans-1,4-polybutadiene is 8.5%, and 1,2-polybutadiene is 47.7%.

[0046] The initial decomposition temperature of the polybutadiene / silica composite in air is 432.7℃.

[0047] Compared with Comparative Example 1, the initial thermal decomposition temperature increased by 7.4℃, and the thermal stability was improved.

[0048] Example 5

[0049] The catalyst and polymerization process are the same as in Example 1, except that cobalt compound A is cobalt isooctanoate, and 259 mg of SiO2 (with a specific surface area of ​​317 m²) is added to a dry polymerization reactor. 2 / g, surface double bond content is 5mmol / kg), silicon to monomer mass ratio is 5%, cobalt to monomer molar ratio is 2×10 -4 :1, The molar ratio of triisobutylaluminum to monomer is 3×10 -3 1. The feeding sequence is as follows: first add SiO2, then add hexane solution of Bd and hexane solution of cobalt isooctanoate, and finally add triisobutylaluminum.

[0050] In the obtained polybutadiene / silica composite, the mass content of polybutadiene was 86.1%, and the mass content of silica was 13.9%, both uniformly dispersed in the composite. Furthermore, the polybutadiene structural units contained 51.4% cis-1,4-, 7.0% trans-1,4-, and 41.6% 1,2-.

[0051] The initial decomposition temperature of the polybutadiene / silica composite in air is 439.3℃.

[0052] Compared with Comparative Example 1, the initial thermal decomposition temperature increased by 14.0℃, and the thermal stability was improved.

[0053] Example 6

[0054] The catalyst and polymerization process are the same as in Example 1, except that 52 mg of nano-SiO2 (with a specific surface area of ​​293 m²) is added to the dry polymerization reactor. 2 / g (surface double bond content of 0.1 mmol / kg), making the mass ratio of SiO2 to monomer 1%, SiO2 and cobalt neodecanoate in hexane solution were mixed at 30°C for 1 h, and the polymerization reaction was carried out at 30°C for 3 h. In the obtained polybutadiene / silica composite, the mass content of polybutadiene was 97.7%, the mass content of silica was 2.3%, and they were uniformly dispersed in the composite. In addition, in the polybutadiene structural units, the content of cis-1,4 was 63.2%, the content of trans-1,4 was 8.7%, and the content of 1,2- was 28.1%.

[0055] The polybutadiene / silica composite has an initial decomposition temperature of 435.3℃ in air; a tensile strength of 1.12MPa; an elongation at break of 470%; a tanδ value of 0.14 at 0℃ and a tanδ value of 0.04 at 60℃.

[0056] Compared with Comparative Example 1 (butadiene rubber industrial product BR9000), the initial thermal decomposition temperature increased by 10℃, and the thermal stability was improved; the tensile strength increased by 7.0 times, effectively improving the physical and mechanical properties; the tanδ value at 0℃ increased by 3.1 times, and the tanδ value at 60℃ decreased by 6.2 times, which can effectively improve the rubber's anti-slip properties and reduce rolling resistance and heat generation.

[0057] Example 7

[0058] The catalyst and polymerization process are the same as in Example 1, except that 52 mg of nano-SiO2 (with a specific surface area of ​​293 m²) is added to the dry polymerization reactor. 2 / g, with a surface double bond content of 0.1 mmol / kg), resulting in a SiO2 to monomer mass ratio of 1%. The SiO2 and cobalt neodecanoate solution in hexane were aged at 60°C for 1 h, and the polymerization reaction was carried out at 60°C for 3 h. In the resulting polybutadiene / silica composite, the polybutadiene mass content was 97.3%, the silica mass content was 2.7%, and they were uniformly dispersed in the composite. Furthermore, the polybutadiene structural units contained 57.1% cis-1,4 structures, 12.1% trans-1,4 structures, and 30.8% 1,2-.

[0059] The polybutadiene / silica composite has an initial decomposition temperature of 432.6℃ in air; a tensile strength of 1.36MPa; a tanδ value of 0.15 at 0℃ and a tanδ value of 0.04 at 60℃.

[0060] Compared with Comparative Example 1 (industrial product of butadiene rubber BR9000), the initial thermal decomposition temperature is increased by 7.3°C, the thermal stability is improved; the tensile strength is increased by 8.7 times, the physical and mechanical properties are effectively improved; the tan δ value at 0°C is increased by 3.4 times, the tan δ value at 60°C is decreased by 6.2 times, the wet skid resistance of the rubber is effectively improved, and the rolling resistance and heat generation are reduced.

[0061] Example 8

[0062] The catalyst and the polymerization process are the same as in Example 1, except that 52 mg of modified nano-SiO2 (specific surface area of 308 m 2 / g, surface double bond content of 1 mmol / kg) is added to the dry polymerization reactor, so that the mass ratio of SiO2 to monomer is 1%, and the mass-volume ratio of monomer (D) to monomer and solvent (D+E) is 64.8 g:1 L. In the obtained polybutadiene / silica composite, the mass content of polybutadiene is 95.9%, the mass content of silica in the polymerization product is 4.1%, and the silica is uniformly dispersed in the composite. In addition, the content of cis-1,4 in the polybutadiene structural unit is 53.6%, the content of trans-1,4 is 11.6%, and the content of 1,2 is 34.8%.

[0063] The initial decomposition temperature of the polybutadiene / silica composite in air is 428.9°C, and the tensile strength is 3.50 MPa; the tan δ value at 0°C is 0.16, and the tan δ value at 60°C is 0.05.

[0064] Compared with Comparative Example 1, the initial thermal decomposition temperature is increased by 3.6°C, the thermal stability is improved; the tensile strength is increased by 24.0 times, the physical and mechanical properties are greatly improved; the tan δ value at 0°C is increased by 3.7 times, and the tan δ value at 60°C is decreased by 4.7 times, which effectively improves the wet skid resistance of the rubber and reduces the rolling resistance and heat generation.

[0065] Example 9

[0066] The catalyst and the polymerization process are the same as in Example 1, except that the cobalt compound A is cobalt isooctanoate, the amount of SiO2 (specific surface area of 339 m 2 / g, surface double bond content of 0.5 mmol / kg) is 0.185 g, the mass ratio of silicon to monomer is 2.1%, the molar ratio of cobalt to monomer is 2×10 -4 :1, and the molar ratio of aluminum to monomer is 4.5×10 -31, monomer solution 30 mL, [Bd]=130 g / L, [Ip]=408 g / L, mass volume ratio of monomer to monomer and solvent (D+E) 538 g:1 L. Polymerization reaction at 30℃ for 2 hours. In the obtained poly(butadiene-co-isoprene) / silica composite, the copolymer mass content is 66.9%, the silica mass content is 33.1 wt%, and is uniformly dispersed in the composite. In addition, in the copolymer, the molar content of butadiene structural units is 83.7%, the molar content of isoprene structural units is 16.3%; the content of cis-1,4 in butadiene structural units is 54.0%, the content of trans-1,4 is 3.9%, and the content of 1,2 is 42.1%; the content of cis-1,4 in isoprene structural units is 55.3%, and the content of 3,4 is 44.7%.

[0067] The tensile strength of the poly(butadiene-co-isoprene) / silica composite is 1.29 MPa. Compared with Comparative Example 1 (industrial product of cis-polybutadiene BR9000), the tensile strength is increased by 8.2 times, and the physical and mechanical properties are greatly improved.

[0068] Comparative Example 1

[0069] The thermal stability, tensile strength and dynamic mechanical properties of the raw rubber of the existing cis-polybutadiene industrial product (brand: BR9000) are tested: the initial thermal decomposition temperature in air atmosphere is 425.3℃; the raw rubber tensile strength is 0.14 MPa; the tan δ value at 0℃ is 0.034, and the tan δ value at 60℃ is 0.287.

[0070] The above has described various embodiments of the present application, and the above description is exemplary, not exhaustive, and is not limited to the disclosed embodiments. Many modifications and changes are obvious to those skilled in the art without departing from the scope and spirit of the described embodiments.

Claims

1. A conjugated diene polymer-based composite, wherein, The conjugated diene polymer-based composite is prepared by a method comprising the following steps: Cobalt compound (A), organoaluminum compound (B), silicon-containing compound (C), conjugated diene monomer (D), and solvent (E) are contacted and mixed to carry out a polymerization reaction. After the reaction is completed, the polymerization product is precipitated and dried to obtain the conjugated diene polymer-based composite. The silicon-containing compound (C) is selected from polysiloxanes and / or silicon dioxide. The molar ratio of cobalt compound (A) to conjugated diene monomer (D) is (1 × 10⁻⁶). -6 ~6×10 -4 ):1; The molar ratio of the organoaluminum compound (B) to the conjugated diene monomer (D) is (6 × 10⁻⁶). -4 ~9.0×10 -3 ):1; The mass ratio of the silicon-containing compound (C) to the conjugated diene monomer (D) is (0.1 × 10⁻⁶). -2 ~8×10 -2 ):1; The mass-to-volume ratio of the conjugated diene monomer (D) to the monomer and solvent (D+E) is 40~560 g:1L; The polymer molecular chain contains 40% to 70% cis-1,4-structure, 20% to 50% 1,2-structure, and 2% to 20% trans-1,4-structure, and has a SiO2 mass content of 0.5% to 40%, with the SiO2 uniformly dispersed in the composite.

2. The conjugated diene polymer-based composite according to claim 1, wherein, The polymer molecular chain contains 43% to 64% cis-1,4-structure, 24% to 48% 1,2-structure, 3% to 16% trans-1,4-structure, and 1% to 35% SiO2 by mass, and the SiO2 is uniformly dispersed in the composite.

3. A method for preparing the conjugated diene polymer-based composite according to claim 1 or 2, wherein the preparation method employs a conjugated diene polymerization system comprising the following components: cobalt compound (A), organoaluminum compound (B), silicon-containing compound (C), conjugated diene monomer (D), and solvent (E); The preparation method includes the following steps: The cobalt compound (A), organoaluminum compound (B), silicon-containing compound (C), conjugated diene monomer (D), and solvent (E) are contacted and mixed to carry out a polymerization reaction. After the reaction is completed, the polymerization product is precipitated and dried to obtain the conjugated diene polymer-based composite.

4. The method for preparing the conjugated diene polymer-based composite according to claim 3, wherein, The molar ratio of the cobalt compound (A) to the conjugated diene monomer (D) is (1×10⁻⁶). -6 ~6×10 -4 ):1; The molar ratio of the organoaluminum compound (B) to the conjugated diene monomer (D) is (6 × 10⁻⁶). -4 ~9.0×10 -3 ):1; The mass ratio of the silicon-containing compound (C) to the conjugated diene monomer (D) is (0.1 × 10⁻⁶). -2 ~8×10 -2 ):1; The mass-to-volume ratio of the conjugated diene monomer (D) to the monomer and solvent (D+E) is 40~560 g:1L.

5. The method for preparing the conjugated diene polymer-based composite according to claim 4, wherein, The molar ratio of the cobalt compound (A) to the conjugated diene monomer (D) is (5 × 10⁻⁶). -5 ~5×10 -4 ):1; The molar ratio of the organoaluminum compound (B) to the conjugated diene monomer (D) is (8 × 10⁻⁶). -4 ~8.0×10 -3 ):1; The mass ratio of the silicon-containing compound (C) to the conjugated diene monomer (D) is (0.2 × 10⁻⁶). -2 ~7×10 -2 ):1; The mass-to-volume ratio of the conjugated diene monomer (D) to the monomer and solvent (D+E) is 50~550 g:1L.

6. The method for preparing the conjugated diene polymer-based composite according to claim 4, wherein, The molar ratio of the cobalt compound (A) to the conjugated diene monomer (D) is (8 × 10⁻⁶). -5 ~4×10 -4 ):1; The molar ratio of the organoaluminum compound (B) to the conjugated diene monomer (D) is (9 × 10⁻⁶). -4 ~7.0×10 -3 ):1; The mass ratio of the silicon-containing compound (C) to the conjugated diene monomer (D) is (0.4 × 10⁻⁶). -2 ~6×10 -2 ):1; The mass-to-volume ratio of the conjugated diene monomer (D) to the monomer and solvent (D+E) is 60~540 g:1L.

7. The method for preparing the conjugated diene polymer-based composite according to claim 3, wherein, The cobalt compound (A) is selected from cobalt organic acid salts and / or cobalt acetylacetonate.

8. The method for preparing the conjugated diene polymer-based composite according to claim 7, wherein, The cobalt compound (A) is selected from at least one compound selected from diacetylacetonate cobalt, triacetylacetonate cobalt, naphthenate cobalt, neodecanoate cobalt, cobalt benzoate, cobalt stearate, cobalt octanoate, cobalt isooctanoate, cobalt oleate, and cobalt linoleate.

9. The method for preparing the conjugated diene polymer-based composite according to claim 8, wherein, The cobalt compound (A) is selected from at least one compound selected from cobalt naphthenate, cobalt octanoate, cobalt neodecanoate and cobalt isooctanoate.

10. The method for preparing the conjugated diene polymer-based composite according to claim 3, wherein, The organoaluminum compound (B) is of the general formula AlR 1 3 and / or general formula AlHR 2 Compound 2, R 1 and R 2 Each is an alkyl group that is independently C1-C6.

11. The method for preparing the conjugated diene polymer-based composite according to claim 10, wherein, R 1 and R 2 Each is independently selected from ethyl, propyl, or butyl.

12. The method for preparing the conjugated diene polymer-based composite according to claim 10, wherein, The organoaluminum compound (B) is selected from at least one compound selected from trimethylaluminum, triethylaluminum, tripropylaluminum, tributylaluminum, tripentylaluminum, trihexylaluminum, diethylaluminum hydride, and dibutylaluminum hydride.

13. The method for preparing the conjugated diene polymer-based composite according to claim 12, wherein, The organoaluminum compound (B) is selected from at least one compound selected from triethylaluminum, triisobutylaluminum, diethylaluminum hydride, and diisobutylaluminum hydride.

14. The method for preparing the conjugated diene polymer-based composite according to claim 3, wherein, The polysiloxane is silicone oil; The silicon dioxide is obtained by precipitation or gas phase method.

15. The method for preparing the conjugated diene polymer-based composite according to claim 14, wherein, The polysiloxane is selected from at least one compound selected from methyl silicone oil, ethyl silicone oil, phenyl silicone oil, methyl hydrogen silicone oil, methyl phenyl silicone oil, methyl chlorophenyl silicone oil, methyl ethoxy silicone oil, methyl trifluoropropyl silicone oil, methyl vinyl silicone oil, methyl hydroxy silicone oil, ethyl hydrogen silicone oil, hydroxy hydrogen silicone oil, and cyanide silicone oil.

16. The method for preparing the conjugated diene polymer-based composite according to claim 15, wherein, The polysiloxane is selected from at least one compound selected from methyl silicone oil, ethyl silicone oil, methyl hydrogen silicone oil, ethyl hydrogen silicone oil and hydroxyl hydrogen silicone oil.

17. The method for preparing the conjugated diene polymer-based composite according to claim 14, wherein, The specific surface area of ​​the silicon dioxide is 150~450 m². 2 / g.

18. The method for preparing the conjugated diene polymer-based composite according to claim 17, wherein, The specific surface area of ​​the silicon dioxide is 175~350 m². 2 / g.

19. The method for preparing the conjugated diene polymer-based composite according to claim 14, wherein, The surface double bond content of the silica is 0.01–300 mmol / kg.

20. The method for preparing the conjugated diene polymer-based composite according to claim 19, wherein, The surface double bond content of the silica is 0.05–260 mmol / kg.

21. The method for preparing the conjugated diene polymer-based composite according to claim 3, wherein, The conjugated diene monomer (D) is selected from at least one of butadiene, isoprene, 2-methyl-1,3-pentadiene, 2,4-hexadiene, styrene, and methylstyrene; The solvent (E) is a hydrocarbon compound.

22. The method for preparing the conjugated diene polymer-based composite according to claim 21, wherein, The conjugated diene monomer (D) is selected from at least one compound selected from butadiene, isoprene, styrene and methylstyrene.

23. The method for preparing the conjugated diene polymer-based composite according to claim 22, wherein, The conjugated diene monomer (D) is selected from at least one compound selected from butadiene, isoprene and styrene.

24. The method for preparing the conjugated diene polymer-based composite according to claim 21, wherein, The solvent (E) is at least one of aliphatic hydrocarbons, alicyclic hydrocarbons, and aromatic hydrocarbons.

25. The method for preparing the conjugated diene polymer-based composite according to claim 24, wherein, The solvent (E) is selected from at least one compound selected from butane, pentane, hexane, cyclohexane, heptane, octane, methylcyclohexane, benzene, toluene, xylene and trimethylbenzene.

26. The method for preparing the conjugated diene polymer-based composite according to claim 25, wherein, The solvent (E) is selected from at least one compound selected from butane, pentane, hexane, cyclohexane and toluene.

27. The method for preparing the conjugated diene polymer-based composite according to claim 3, wherein, The mixing method is selected from any one of C-(A+E)-(D+E)-(B+E), (C+A+E)-(D+E)-(B+E), C-(D+E)-(A+E)-(B+E), C-(D+E)-(B+E)-(A+E), (D+E)-C-(A+E)-(B+E), (D+E)-C-(B+E)-(A+E), (D+E)-(A+E)-C-(B+E), and (D+E)-(A+E)-BC.

28. The method for preparing the conjugated diene polymer-based composite according to claim 3, wherein, The polymerization reaction temperature is -60℃ to 120℃; the reaction time is 30 min to 30 h. All steps were performed under inert gas protection.

29. The method for preparing the conjugated diene polymer-based composite according to claim 28, wherein, The polymerization reaction temperature is -30℃ to 110℃; the reaction time is 1h to 20h.

30. The method for preparing the conjugated diene polymer-based composite according to claim 29, wherein, The polymerization reaction is carried out at a temperature of 0℃ to 105℃ and for a reaction time of 30 min to 3 h.

31. The method for preparing the conjugated diene polymer-based composite according to claim 28, wherein, All steps were performed under nitrogen protection.