Modified fluorosilicone polymer, modified polydiene rubber and preparation method of modified fluorosilicone polymer and modified polydiene rubber

Abstract

The invention discloses a modified fluorosilicone polymer, modified polydiene rubber and preparation of the modified fluorosilicone polymer and the modified polydiene rubber. The modified fluorosilicone polymer is a product obtained after substitution reaction of a chlorosilane-terminated fluorosilicone polymer and polydiene alkyl lithium. When the modified fluorosilicone polymer provided by the invention is used for modifying the polydiene rubber, the problems of wear resistance and thermal stability of the polydiene rubber and generation of heat by friction in molecular chains in a rubber body can be improved, and the service life of the rubber is further prolonged.

Description

Technical Field

[0001] The invention relates to a modified fluorosilicone polymer, a modified polydiene rubber and a preparation method thereof. Background Art

[0002] In recent years, with the rapid development of new energy vehicles and the petroleum industry, the use of rubber sealing materials has increased, such as pneumatic parts, rubber plugs, O-rings, etc. These rubber sealing materials are mostly contact-type dynamic sealing parts. When the parts are in a dynamic working condition, they will produce friction on the surface of the friction pair, causing the surface of the rubber product to generate intense heat and wear. The sealing performance of the rubber product will gradually weaken and eventually cause failure. Organic fluorine materials can effectively reduce the wear between rubber seals and friction pairs, improve the lubricity between the two, and reduce the roughness of the friction substrate surface, thereby increasing the service life of the sealing parts. Therefore, organic fluorine materials play a key role in rubber seals. At present, organic fluorine is mainly used to improve the friction resistance of rubber surfaces through the following three methods: (1) spraying fluorine-containing coatings on the surface of rubber products; (2) plasma fluorination treatment of the surface of rubber products; (3) adding polytetrafluoroethylene powder to the rubber mixing formula. Summary of the invention

[0003] The present invention is made in order to improve the wear resistance, high temperature resistance, thermal stability of rubber and the problem of heat generation due to friction within the molecular chains of the colloid.

[0004] As a first aspect of the present invention, it relates to a modified fluorosilicone polymer, and the modified fluorosilicone polymer has the following structure:

[0005]

[0006] Wherein: m is 0 to 2, n is 1 to 3, R is a polydiene segment, R f It is a fluorinated chain segment.

[0007] In one or some optional embodiments, the fluorinated segment R f It is perfluoropolyether or liquid fluororubber;

[0008] The perfluoropolyether has the following structure:

[0009]

[0010] Among them, the value of p is 5 to 10, and the value of q is 5 to 10;

[0011] The liquid fluororubber has the following structure:

[0012]

[0013] Among them, the value of a is 1 to 20, the value of b is 1 to 20, and the value of c is 1 to 5.

[0014] In one or some optional embodiments, the polydiene segment R is polybutadiene, styrene-butadiene rubber, polyisoprene or isoprene-styrene polymer;

[0015] The polybutadiene has the following structure:

[0016]

[0017] The styrene-butadiene rubber has the following structure:

[0018]

[0019] The polyisoprene has the following structure:

[0020]

[0021] The isoprene-styrene polymer has the following structure:

[0022]

[0023] Among them, the value of x is 1 to 500, the value of y is 1 to 20, the value of z is 1 to 20, and the value of o is 1 to 20.

[0024] As a second aspect of the present invention, it relates to a method for preparing the above-mentioned modified fluorosilicone polymer, which comprises: subjecting a chlorosilane-terminated fluorosilicone polymer to a substitution reaction with a polydiene alkyl lithium to obtain the modified fluorosilicone polymer.

[0025] In one or some optional embodiments, the molar ratio of the terminal chlorosilane fluorosilicone polymer to the polydiene alkyl lithium is 1:1-6.

[0026] In one or some optional embodiments, the reaction conditions of the substitution reaction include: the reaction temperature is room temperature to 60° C., and the reaction time is 0.5 to 2 hours.

[0027] In one or some optional embodiments, the polydiene alkyl lithium includes at least one of polybutadiene alkyl lithium and butadiene-styrene copolymer alkyl lithium.

[0028] In one or some optional embodiments, the chlorosilane-terminated fluorosilicone polymer is obtained by a hydrosilylation reaction of an allyl ether-terminated fluoropolymer and a hydrogen-containing chlorosilane.

[0029] In one or some preferred embodiments, the terminal allyl ether fluorinated polymer is selected from at least one of terminal allyl ether K-type perfluoropolyether, terminal allyl ether Y-type perfluoropolyether, terminal allyl ether Z-type perfluoropolyether or liquid fluororubber 246.

[0030] In one or some optional embodiments, the average molecular weight of the terminal allyl ether fluorinated polymer is 1,000 to 10,000.

[0031] In one or some optional embodiments, the hydrogen-containing chlorosilane is selected from at least one of dimethyl monochlorohydrogensilane and methyl dichlorohydrogensilane.

[0032] In one or some optional embodiments, the molar ratio of the terminal allyl ether fluorinated polymer to the hydrogen-containing chlorosilane is 1:1-20.

[0033] In one or some optional embodiments, the reaction conditions of the hydrosilylation reaction include: a reaction temperature of 85 to 100° C. and a reaction time of 3 to 12 hours.

[0034] As a third aspect of the present invention, it relates to a modified polydiene rubber, which comprises the above-mentioned modified fluorosilicone polymer and polydiene rubber.

[0035] In one or some optional embodiments, the mass ratio of the modified fluorosilicone polymer to the polydiene rubber is 1 to 5:100.

[0036] As a fourth aspect of the present invention, it relates to a method for preparing a modified polydiene rubber, the method comprising:

[0037] The modified fluorosilicone polymer and unvulcanized polydiene rubber are added into a roller, and then milled and vulcanized to obtain a fluorosilicone polymer block polydiene rubber.

[0038] The invention uses a block synthesis method to block the terminal chlorosilane fluorosilicone polymer molecular chain on a polydiene alkyllithium molecular chain to obtain a terminal chlorosilane fluorosilicone polymer obtained by capping a terminal allyl ether fluoropolymer with silicon and chlorine, thereby obtaining a modified fluorosilicone polymer. Since the terminal chlorosilane fluorosilicone polymer can react with the carbon-carbon double bonds on the polydiene alkyllithium molecular chain, the terminal chlorosilane fluorosilicone polymer can be effectively dispersed in the polydiene alkyllithium. The modified fluorosilicone polymer is added as an additive to unvulcanized rubber, thereby improving the performance of the rubber and broadening the application field of the rubber. The invention has important application prospects in the fields of aerospace sealing materials, oilfield products, medical equipment, daily necessities, sealing gaskets for new energy equipment, solvent-resistant rubber products for the outer layer of oil pipes, and the like.

[0039] The modified fluorosilicone polymer provided by the present invention has the advantages of low surface energy, low friction, high lubrication performance, corrosion resistance, wide temperature range, high temperature resistance, high insulation, low glass transition temperature, etc., because the perfluoropolyether segment, liquid fluororubber segment and polysiloxane segment in the fluorine-containing segment contained in the modified fluorosilicone polymer have the advantages of low surface energy, low friction, high lubrication performance, corrosion resistance, wide temperature range, high temperature resistance, high insulation, low glass transition temperature, etc. Therefore, the modified fluorosilicone polymer is applied as an additive to unvulcanized rubber to improve the wear resistance and thermal stability of the rubber and the problem of frictional heat generation within the molecular chain of the colloid.

[0040] The preparation method provided by the invention has the advantages of simple operation, short process flow, small equipment investment, easy process control and environmental friendliness. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] Figure 1 is the infrared spectrum of the modified fluorosilicone polymer prepared in Example 1;

[0042] Figure 2 This is the infrared spectrum of the modified fluorosilicone polymer prepared in Example 2. DETAILED DESCRIPTION

[0043] The following is a detailed description of the embodiments of the present invention: The embodiments of the present invention are implemented on the premise of the technical solution of the present invention, and detailed implementation methods and processes are given, but the protection scope of the present invention is not limited to the following embodiments. The process parameters for which specific conditions are not specified in the following embodiments are generally based on conventional conditions.

[0044] The endpoints and any values ​​of the ranges disclosed in the present 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 each range, the endpoint values ​​of each range and the individual point values, and the individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be regarded as specifically disclosed in the present invention.

[0045] The inventors referred to the paper "Zhang Lingxin et al. Friction properties of HNBR modified by spraying fluorine-containing coating on the surface [J], Rubber Industry, 2011, 58(5): 261-268." and used water-based polytetrafluoroethylene coating to spray on the surface of hydrogenated nitrile rubber. The inventors analyzed that although this technical solution reduced the friction coefficient from 1.0 to 0.15-0.20, it had poor adhesion, short effective time, and could not penetrate into the interior of the colloid, and could not improve the problem of frictional heat generation within the molecular chain. The inventors referred to the paper "Mi Tong et al. Study on the Friction Reduction Mechanism of Plasma Fluorination Modified Nitrile Rubber Surface Coating [J], Rubber Industry, 2013, 60(9): 527-532." and used carbon tetrafluoride as the reaction gas to perform plasma fluorination modification on the surface of nitrile rubber. It was found that although the friction coefficient of this technical solution was reduced from 1.89 to 1.02-1.51, it could only fluorinate the surface of the nitrile rubber in a shallow layer. Once worn, it could not play a friction reduction role and had a short service life, which did not meet the requirements of long-term use. In addition, the fluorination treatment on the surface could easily destroy the surface structure of the rubber, generate free radicals, and easily cause the molecular chains to break, and also could not improve the problem of frictional heat generation within the molecular chains. The inventors referred to the paper "Liu Yang. Research on the performance of polytetrafluoroethylene modified styrene butadiene / nitrile rubber, Northwest Normal University [D], 2014.", and found that the technical solution can improve the oil resistance and tensile strength of rubber by blending polytetrafluoroethylene dispersion with emulsion polystyrene butadiene, and to a certain extent improve the scorch resistance of the rubber, thereby improving processing safety. In addition, the use of polytetrafluoroethylene dispersion blended with nitrile rubber can also improve the oil resistance and tensile properties of nitrile rubber. However, the preparation technology has the problem that polytetrafluoroethylene powder is incompatible with the non-fluorine rubber matrix, which is easy to produce phase separation, resulting in changes in crosslinking density, affecting the performance of the product. During long-term use, polytetrafluoroethylene powder gradually precipitates on the surface of the colloid, resulting in cavities inside the rubber, which to a certain extent destroys the mechanical properties and heat stability of the product and greatly reduces its service life.

[0046] In view of the fact that the above methods did not meet the inventor's expectations, the inventor made the present invention after further research and development, which effectively solved the compatibility problem between organic fluorine materials and non-fluorine rubbers, and improved the wear resistance, high temperature resistance, thermal stability and frictional heat generation within the molecular chains of traditional rubbers.

[0047] The raw materials and their sources used in the embodiments of the present invention are:

[0048] Terminal allyl ether perfluoropolyether, terminal allyl ether liquid rubber 246, perfluorocyclohexane, double-terminal hydrogen-containing silicone oil (the mass fraction of active hydrogen is 0.166%, 0.115% and 0.052%): industrial grade, Shenzhen Tianke New Materials Co., Ltd.

[0049] Butadiene-styrene copolymer alkyl lithium, polybutadiene alkyl lithium, nitrile rubber (combined with acrylonitrile, 35% to 40%), zinc oxide, stearic acid, sulfur, accelerator CZ, N550, dioctyl phthalate, vulcanizer DCP and crosslinking agent TAIC: industrial grade, PetroChina Lanzhou Chemical Research Center.

[0050] Speier catalyst, dimethyl monochlorosilane, anhydrous methanol: analytical grade, Shanghai Aladdin Biochemical Technology Co., Ltd.

[0051] The evaluation and analysis methods used in the embodiments of the present invention are: DMA: test temperature range: -50°C to 120°C, heating rate: 3°C / min, force: 2.5N, frequency: 5Hz, displacement: 0.8μm. Akron wear volume: in accordance with GB / T1689-1998. Friction coefficient: in accordance with GB / T 22895-2008.

[0052] It should be noted that the terminal chlorosilane fluorosilicone polymer involved in the present invention is obtained by a hydrosilylation reaction of a terminal allyl ether fluoropolymer and a hydrogen-containing chlorosilane, but the present invention does not limit the silane addition reaction method, as long as the method can achieve the preparation of the terminal chlorosilane fluorosilicone polymer, for example, the hydrosilylation reaction method can be: adding the terminal allyl ether fluoropolymer and the hydrogen-containing chlorosilane into a reaction container, using m-ditrifluorotoluene as a solvent, and carrying out a hydrosilylation reaction while stirring in the presence of a Speier catalyst, the reaction temperature is 85 to 100°C, the reaction time is 3 to 12 hours, and after the reaction is completed, the solvent and excess unreacted hydrogen-containing chlorosilane are removed by reduced pressure distillation to obtain a terminal chlorosilane fluorosilicone polymer.

[0053] The modified fluorosilicone polymer provided by the present invention is obtained by a substitution reaction between a terminal chlorosilane fluorosilicone polymer and a polydiene alkyl lithium, but the present invention does not limit the substitution reaction method, as long as the method can achieve the preparation of the modified fluorosilicone polymer, for example, the substitution reaction method can be: adding a hexane solution of the polydiene alkyl lithium to a reaction container, and then adding the terminal chlorosilane fluorosilicone polymer to the reaction container while stirring for a substitution reaction, the reaction temperature is room temperature to 60°C, the reaction time is 0.5 to 2 hours, after the reaction is completed, anhydrous methanol is added and continued to be stirred for 5 minutes, then the mixture solution in the reaction container is added to boiling water, the hexane and methanol are removed, and then dried to obtain the modified fluorosilicone polymer.

[0054] The unvulcanized polydiene rubber involved in the present invention is a conventional polydiene rubber, such as nitrile rubber or styrene-butadiene rubber, and its formula can be: 100 parts of nitrile rubber NBR, 5 parts of zinc oxide, 1 part of stearic acid, 1 part of sulfur, 1.8 parts of accelerator CZ, 70 parts of N550, 10 parts of dioctyl phthalate, 3 parts of vulcanizing agent DCP and 1.2 parts of crosslinking agent TAIC.

[0055] The preparation method of the modified polydiene rubber involved in the present invention is a conventional method, for example, the modified fluorosilicone polymer and the unvulcanized polydiene rubber are uniformly mixed in a mass ratio of 1 to 5:100, and then added to a roller for open refining and vulcanization to obtain the modified polydiene rubber. The specific reaction conditions can be adjusted according to the mass of the added raw materials. Considering the dispersibility of the modified fluorosilicone polymer in the polydiene rubber, the mass ratio of the modified fluorosilicone polymer and the unvulcanized polydiene rubber used in the present invention is 1:10.

[0056] Example 1

[0057] 50 g (Mw=1580, 0.032 mol) of terminal allyl ether Z-type perfluoropolyether and 12 g (0.13 mol) of dimethyl monochlorohydrosilane were added to a three-necked flask, and then 50 mL of m-ditrifluorotoluene and 2 mL of Speier catalyst were added, and stirred at 85° C. for 12 h. After the reaction was completed, the solvent and excess unreacted dimethyl monochlorohydrosilane were removed by distillation under reduced pressure to obtain about 55 g of liquid, which was then diluted with 220 g of m-ditrifluorotoluene to obtain product 1 with a solid content of 20%.

[0058] 500 g (Mw=20000, mass fraction of 10%, 0.0025 mol) of butadiene-styrene copolymer alkyllithium hexane solution was added to a clean 1L conical flask, and then 11.1 g of product 1 was injected into the conical flask within 5 minutes while stirring for substitution reaction. After stirring at 40°C for 30 minutes, the color in the conical flask no longer changed, and the substitution reaction was completed; then 10 mL of anhydrous methanol was added and stirred for 5 minutes; then the mixture solution in the conical flask was slowly added to boiling water to remove hexane and methanol, precipitate the polymer, and then dried in vacuo at 90°C for 5 hours to obtain a modified fluorosilicone polymer.

[0059] The infrared spectrum of the modified fluorosilicone polymer prepared in this example is as follows: Figure 1 As shown by Figure 1 Analysis shows that 3073cm -1 The CH peak of the carbon-carbon double bond on the chain segment of styrene-butadiene copolymer is 1620-1600 cm -1 C=C peak on the butadiene repeating unit, 1498-1411 cm -1 C=C peak on the benzene ring, 1214~1066cm-1 The peaks are CF and CO on the perfluoropolyether chain segment, indicating that the butadiene-styrene copolymer was successfully grafted with the Z-type perfluoropolyether.

[0060] Example 2

[0061] Take 500g (Mw=2000, mass fraction of 10%, 0.025mol) of polybutadiene alkyl lithium hexane solution and add it to a clean 1L conical flask, then inject 111g of product 1 in Example 1 into the conical flask within 5 minutes for substitution reaction. After stirring at room temperature for 25 minutes, the color in the conical flask no longer changes, and the substitution reaction is completed; then add 10mL of anhydrous methanol and stir for 5 minutes; then slowly add the mixture solution in the conical flask into boiling water to remove hexane and methanol, precipitate the polymer, and then vacuum dry at 90°C for 5 hours to obtain a modified fluorosilicone polymer.

[0062] The infrared spectrum of the modified fluorosilicone polymer prepared in this example is as follows: Figure 2 As shown by Figure 2 Analysis shows that 3073 and 1633 cm -1 The CH peak of the carbon-carbon double bond on the polybutadiene chain segment is 1214-1066 cm -1 The peaks are CF and CO on the perfluoropolyether chain segment, indicating that polybutadiene and Z-type perfluoropolyether were successfully grafted.

[0063] Example 3

[0064] 50 g (Mw=1580, 0.032 mol) of terminal allyl ether K-type perfluoropolyether and 15 g (0.13 mol) of dimethyl monochlorosilane were added to a three-necked flask, and then 50 mL of m-ditrifluorotoluene and 2 mL of Speier catalyst were added, and stirred at 100° C. for 12 h. After the reaction was completed, the solvent and excess unreacted dimethyl monochlorosilane were removed by reduced pressure distillation to obtain about 57 g of liquid, which was then diluted with 228 g of m-ditrifluorotoluene to obtain product 2 with a solid content of 20%.

[0065] Take 500g (Mw=20000, mass fraction of 10%, 0.0025mol) of butadiene-styrene copolymer alkyllithium hexane solution and add it to a clean 1L conical flask, then inject 5.55g of product 2 into the conical flask within 5 minutes for substitution reaction. After stirring at room temperature for 25 minutes, the color in the conical flask no longer changes, and the substitution reaction is completed; then add 10mL of anhydrous methanol and stir for 5 minutes; then slowly add the mixture solution in the conical flask into boiling water to remove hexane and methanol, precipitate the polymer, and then vacuum dry at 90°C for 5 hours to obtain a modified fluorosilicone polymer.

[0066] Example 4

[0067] 50 g (Mw=3200, 0.016 mol) of terminal allyl ether liquid fluororubber 246 and 6.1 g (0.064 mol) of dimethyl monochlorosilane were added to a three-necked flask, and then 50 mL of m-ditrifluorotoluene and 2 mL of Speier catalyst were added, and stirred at 100° C. for 12 h. After the reaction was completed, the solvent and excess unreacted dimethyl monochlorosilane were removed by distillation under reduced pressure to obtain about 52 g of liquid, which was then diluted with 208 g of m-ditrifluorotoluene to obtain product 3 with a solid content of 20%.

[0068] 500 g (Mw=20000, mass fraction of 10%, 0.0025 mol) of butadiene-styrene copolymer alkyllithium hexane solution was added to a clean 1L conical flask, and then 21.2 g of product 3 was injected into the conical flask within 5 minutes for substitution reaction. After stirring at room temperature for 25 minutes, the color in the conical flask no longer changed, and the substitution reaction was completed; then 10 mL of anhydrous methanol was added and stirred for 5 minutes; then the mixture solution in the conical flask was slowly added to boiling water to remove hexane and methanol, precipitate the polymer, and then dried in vacuo at 90°C for 5 hours to obtain a modified fluorosilicone polymer.

[0069] Example 5

[0070] 50 g (Mw=1580, 0.032 mol) of terminal allyl ether Z-type perfluoropolyether and 15 g (0.13 mol) of methyldichlorosilane were added to a three-necked flask, and then 50 mL of m-ditrifluorotoluene and 2 mL of Speier catalyst were added, and stirred at 100° C. for 12 h; after the reaction was completed, the solvent and excess unreacted methyldichlorosilane were removed by distillation under reduced pressure to obtain about 55 g of liquid, which was then diluted with 220 g of m-ditrifluorotoluene to obtain product 4 with a solid content of 20%.

[0071] 500 g (Mw=20000, mass fraction of 10%, 0.0025 mol) of butadiene-styrene copolymer alkyllithium hexane solution was added to a clean 1L conical flask, and then 5.6 g of product 4 was injected into the conical flask within 5 minutes while stirring for substitution reaction. After stirring at 40°C for 30 minutes, the color in the conical flask no longer changed, and the substitution reaction was completed; then 10 mL of anhydrous methanol was added and stirred for 5 minutes; then the mixture solution in the conical flask was slowly added to boiling water to remove hexane and methanol, precipitate the polymer, and then vacuum dried at 90°C for 5 hours to obtain a modified fluorosilicone polymer, which is perfluoropolyether silane-modified styrene-butadiene rubber (III).

[0072] Example 6

[0073] 50 g (Mw=1580, 0.032 mol) of terminal allyl ether K-type perfluoropolyether and 15 g (0.13 mol) of methyldichlorosilane were added to a three-necked flask, and then 50 mL of m-ditrifluorotoluene and 2 mL of Speier catalyst were added, and stirred at 100° C. for 12 h. After the reaction was completed, the solvent and excess unreacted methyldichlorosilane were removed by distillation under reduced pressure to obtain about 53 g of liquid, which was then diluted with 212 g of m-ditrifluorotoluene to obtain product 5 with a solid content of 20%.

[0074] 500 g (Mw=20000, mass fraction of 10%, 0.0025 mol) of butadiene-styrene copolymer alkyllithium hexane solution was added to a clean 1L conical flask, and then 9.8 g of product 5 was injected into the conical flask within 10 minutes for substitution reaction. After stirring at room temperature for 45 minutes, the color in the conical flask no longer changed, and the substitution reaction was completed; then 10 mL of anhydrous methanol was added and stirred for 5 minutes; then the mixture solution in the conical flask was slowly added to boiling water to remove hexane and methanol, precipitate the polymer, and then dried in vacuo at 90°C for 5 hours to obtain a modified fluorosilicone polymer.

[0075] Example 7

[0076] 50 g (Mw=3080, 0.016 mol) of terminal allyl ether K-type perfluoropolyether and 9.2 g (0.08 mol) of methyldichlorosilane were added to a three-necked flask, and then 50 mL of m-ditrifluorotoluene and 2 mL of Speier catalyst were added, and stirred at 100° C. for 12 h. After the reaction was completed, the solvent and excess unreacted methyldichlorosilane were removed by distillation under reduced pressure to obtain about 56 g of liquid, which was then diluted with 224 g of m-ditrifluorotoluene to obtain product 6 with a solid content of 20%.

[0077] 500 g (Mw=20000, mass fraction of 10%, 0.0025 mol) of butadiene-styrene copolymer alkyllithium hexane solution was added to a clean 1L conical flask, and then 19.3 g of product 5 was injected into the conical flask within 15 minutes for substitution reaction. After stirring at room temperature for 60 minutes, the color in the conical flask no longer changed, and the substitution reaction was completed; then 10 mL of anhydrous methanol was added and stirred for 5 minutes; then the mixture solution in the conical flask was slowly added to boiling water to remove hexane and methanol, precipitate the polymer, and then dried in vacuo at 90°C for 5 hours to obtain a modified fluorosilicone polymer.

[0078] Example 8

[0079] Preparation of fluorosilicone polymer modified polydiene rubber:

[0080] 2.4kg of unvulcanized nitrile rubber (formulation is 100 parts of nitrile rubber NBR, 5 parts of zinc oxide, 1 part of stearic acid, 1 part of sulfur, 1.8 parts of accelerator CZ, 70 parts of N550, 10 parts of dioctyl phthalate, 3 parts of vulcanizing agent DCP and 1.2 parts of crosslinking agent TAIC) is divided into 8 parts, each of which has a mass of 300g. 30g of the modified fluorosilicone polymer prepared in Examples 1 to 7 is added to 7 parts of unvulcanized nitrile rubber in sequence, and the mixture is opened and rolled respectively, with the surface temperature of the roller being room temperature to 45°C for 20min. Then, the mixture is vulcanized at 160°C, with a molding pressure of 70MPa for 30min to prepare modified polydiene rubber samples 1 to 7. The properties of samples 1 to 7 are shown in Table 1.

[0081] Test Example 1

[0082] One portion of the unvulcanized nitrile rubber in Example 8 was taken and vulcanized according to the same vulcanization process as in Example 8 to prepare rubber sample 8, the properties of which are shown in Table 1.

[0083] Table 1 Wear resistance and loss factor of samples 1 to 8

[0084]

[0085] From the data analysis of Table 1, it can be seen that the use of the modified fluorosilicone polymer provided in the embodiment of the present invention as a vulcanized rubber additive effectively improves the wear resistance of nitrile rubber, reduces the friction coefficient of the colloid surface, and thus can greatly increase the service life of nitrile rubber dynamic seals.

[0086] Although the specific embodiments of the present invention have been described in detail, it will be understood by those skilled in the art. According to all the teachings disclosed, various modifications and replacements can be made to those details, and these changes are all within the protection scope of the present invention. The full scope of the present invention is given by the attached claims and any equivalents thereof.

Claims

1. A modified fluorosilicone polymer, characterized in that: The modified fluorosilicone polymer has the following structure: Wherein: m is 0 to 2, n is 1 to 3, R is a polydiene segment, R f It is a fluorinated chain segment.

2. The modified fluorosilicone polymer according to claim 1, characterized in that The fluorinated segment R f It is perfluoropolyether or liquid fluororubber; The perfluoropolyether has the following structure: Among them, the value of p is 5 to 10, and the value of q is 5 to 10; The liquid fluororubber has the following structure: Among them, the value of a is 1 to 20, the value of b is 1 to 20, and the value of c is 1 to 5.

3. The modified fluorosilicone polymer according to claim 1, characterized in that The polydiene segment R is polybutadiene, styrene-butadiene rubber, polyisoprene or isoprene-styrene polymer; The polybutadiene has the following structure: The styrene-butadiene rubber has the following structure: The polyisoprene has the following structure: The isoprene-styrene polymer has the following structure: Among them, the value of x is 1 to 500, the value of y is 1 to 20, the value of z is 1 to 20, and the value of o is 1 to 20.

4. A method for preparing the modified fluorosilicone polymer according to any one of claims 1 to 3, characterized in that: The method comprises: subjecting a chlorosilane-terminated fluorosilicone polymer to a substitution reaction with a polydiene alkyl lithium to obtain the modified fluorosilicone polymer.

5. The method according to claim 4, characterized in that The molar ratio of the terminal chlorosilane fluorosilicone polymer to the polydiene alkyl lithium is 1:1-6.

6. The method according to claim 4, characterized in that The reaction conditions of the substitution reaction include: the reaction temperature is room temperature to 60° C., and the reaction time is 0.5 to 2 hours.

7. The method according to claim 4, characterized in that The polydiene alkyl lithium includes at least one of polybutadiene alkyl lithium and butadiene-styrene copolymer alkyl lithium.

8. The method according to claim 4, characterized in that The chlorosilane-terminated fluorosilicone polymer is obtained by a hydrosilylation reaction between an allyl ether-terminated fluoropolymer and a hydrogen-containing chlorosilane.

9. The method according to claim 8, characterized in that The terminal allyl ether fluorinated polymer is selected from at least one of terminal allyl ether K-type perfluoropolyether, terminal allyl ether Y-type perfluoropolyether, terminal allyl ether Z-type perfluoropolyether or liquid fluororubber 246.

10. The method according to claim 8, characterized in that The average molecular weight of the terminal allyl ether fluorine-containing polymer is 1,000 to 10,000.

11. The method according to claim 8, characterized in that The hydrogen-containing chlorosilane is selected from at least one of dimethyl monochlorohydrogensilane and methyl dichlorohydrogensilane.

12. The method according to claim 8, characterized in that The molar ratio of the terminal allyl ether fluorinated polymer to the hydrogen-containing chlorosilane is 1:1-20.

13. The method according to claim 8, characterized in that The reaction conditions of the hydrosilylation reaction include: a reaction temperature of 85 to 100° C. and a reaction time of 3 to 12 hours.

14. A modified polydiene rubber, characterized in that: The modified polydiene rubber comprises the modified fluorosilicone polymer and polydiene rubber according to any one of claims 1 to 3.

15. The modified polydiene rubber according to claim 14, characterized in that The mass ratio of the modified fluorosilicone polymer to the polydiene rubber is 1 to 5:

100.

16. The method for preparing the modified polydiene rubber according to claim 14, characterized in that: The method comprises: The modified fluorosilicone polymer and unvulcanized polydiene rubber are added into a roller, and then milled and vulcanized to obtain a fluorosilicone polymer block polydiene rubber.

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