Oil-resistant and anti-aging fluororubber material and preparation method thereof

Abstract

This invention discloses an oil-resistant and anti-aging fluororubber material and its preparation method, which relates to the field of fluororubber technology. It aims to reduce the cost of using fluororubber and improve the interfacial compatibility between nitrile rubber and fluororubber. The preparation method includes the following steps: (1) mixing modified liquid fluororubber and fluororubber to obtain fluororubber compound; (2) mixing nitrile rubber, adding fluororubber compound, mixing, adding a coordinating vulcanizing agent, adding an acid absorber, an antioxidant, and an accelerator, vulcanizing to obtain an oil-resistant and anti-aging fluororubber material.

Description

Technical Field

[0001] This invention relates to the field of fluororubber technology, specifically to an oil-resistant and anti-aging fluororubber material and its preparation method. Background Technology

[0002] Fluororubber is widely used in aerospace, automotive, petrochemical and other fields due to its excellent high temperature resistance and oil resistance. It is a core material for manufacturing key components such as seals and hoses, ensuring stable operation of equipment under extreme working conditions.

[0003] However, fluororubber is expensive. In order to reduce costs, low-cost fillers are usually added in the existing technology, or it is compounded with nitrile rubber, which has similar performance to fluororubber and is cheaper. However, nitrile rubber and fluororubber have poor compatibility, which will reduce the oil resistance and aging resistance of the material.

[0004] In summary, the preparation of an oil-resistant and anti-aging fluororubber material is of great significance. Summary of the Invention

[0005] The present invention aims to provide an oil-resistant and anti-aging fluororubber material and its preparation method, so as to solve the related technical problems existing in the prior art.

[0006] To achieve the above-mentioned objectives, the technical solution adopted by the present invention is as follows: A method for preparing an oil-resistant and anti-aging fluororubber material includes the following steps: (1) Modified liquid fluororubber and fluororubber are mixed to obtain fluororubber compound; (2) Mix nitrile rubber, add fluororubber compound, continue mixing, add acid absorber, antioxidant and accelerator; add vulcanizing agent and mix, vulcanize, to obtain oil-resistant and anti-aging fluororubber material; The mass ratio of the fluororubber to the modified liquid fluororubber is (2~3):1; the raw materials of the oil-resistant and anti-aging fluororubber material include the following components: by mass parts, 20~35 parts nitrile rubber, 70~80 parts fluororubber compound, 7~10 parts vulcanizing agent, 4~7 parts acid absorber, 1~2 parts antioxidant, and 0.8~1.5 parts accelerator.

[0007] A more optimized method for preparing the modified liquid fluororubber is as follows: (1) Disperse silica in an ethanol aqueous solution by ultrasonication, add 3-glycidoxypropyltrimethoxysilane and mix evenly, heat and stir to obtain epoxidized silica; disperse epoxidized silica in deionized water by ultrasonication, remove oxygen by vacuum-nitrogen circulation, add dopamine and mix, heat and stir to react, adjust pH to weak acidity, wash to obtain dopamine modified silica; (2) Add the carboxyl-terminated liquid fluororubber to tetrahydrofuran and mix evenly. Add ethylene glycol diglycidyl ether, dopamine-modified silica, and tertiary amine catalyst and mix. Heat and stir for 4 to 8 hours to obtain modified liquid fluororubber.

[0008] More optimized, the mass ratio of the silica to 3-glycidoxypropyltrimethoxysilane is 10:(1~2); the mass ratio of the epoxidized silica to dopamine is 10:(0.3~0.7).

[0009] In a more optimized form, the raw materials for the modified liquid fluororubber include the following components: by mass, 10 parts of carboxyl-terminated liquid fluororubber, 0.5 to 1.5 parts of ethylene glycol diglycidyl ether, 1 to 2 parts of dopamine-modified silica, and 0.05 to 0.12 parts of tertiary amine catalyst.

[0010] In the scheme, the preparation method of carboxyl-terminated liquid fluororubber is as follows: (1) Add fluororubber to acetone and stir for 4-6 hours, lower the temperature to 8-10℃, add 8g of benzyltrimethylammonium chloride and an equal mass of ammonium chloride, stir for 10-20 minutes, add 30-40g of potassium hydroxide aqueous solution with a concentration of 40-45wt%, stir for 20-30 minutes, add 40-45g of hydrogen peroxide with a concentration of 30wt%, stir at room temperature for 6-8 hours, and end the reaction; (2) Add 37wt% hydrochloric acid to step (1) to adjust the pH to 2, filter, distill under reduced pressure, add ethyl acetate to mix, add deionized water, extract; collect the target product, dry under vacuum to remove water, and obtain terminal carboxyl liquid fluororubber.

[0011] More optimally, the mixing temperature is 90~115℃, and the mixing time is 20~40 minutes; the vulcanization process conditions are: temperature 150~175℃, pressure 7~15MPa, and time 15~30 minutes.

[0012] In a more optimized form, the raw materials of the vulcanizing agent include the following components: by mass parts, 1-2 parts triallyl isocyanurate, 3-6 parts dicumyl peroxide, and 5-10 parts coordination vulcanizing agent.

[0013] In a more optimized form, the coordinating sulfide includes one or more of ferric chloride, copper chloride, and zinc chloride.

[0014] Compared with the prior art, the beneficial effects of the present invention are as follows: This invention combines fluororubber and nitrile rubber to take into account the excellent oil resistance and aging resistance of fluororubber; however, the two have a large difference in polarity, and direct blending easily forms an island-separation structure, which is prone to agglomeration and stacking, causing interface defects and significantly reducing the overall oil resistance and long-term anti-aging performance of the material.

[0015] In this scheme, dopamine-modified silica is reacted with carboxyl-terminated liquid fluororubber and ethylene glycol diglycidyl ether under catalytic conditions to prepare modified liquid fluororubber. This modified liquid fluororubber can significantly improve the overall surface polarity of the fluororubber system, effectively reduce the polarity difference between the fluororubber and nitrile rubber phases, and greatly improve the interfacial compatibility between the two phases. To address the issue of high bulk viscosity of the carboxyl-terminated liquid fluororubber, the rheological properties of the system are optimized through chemical modification with nanofillers.

[0016] This invention first uses 3-glycidyl etheroxypropyltrimethoxysilane to modify the surface of nanomaterials, and controls the ratio of the two to avoid excessive grafting and resulting excessive steric hindrance, so as to ensure that dopamine can be efficiently grafted onto the surface of nanomaterials to prepare dopamine-modified silica.

[0017] The compounding process involves compounding a coordination vulcanizing agent, which forms a coordination crosslinking network with dopamine polar groups and rubber active groups, reducing the gap between the two phases, effectively inhibiting the aggregation and stacking of island phase structures in the blended system, blocking oil molecules and oxygen permeation pores, and simultaneously improving the resistance to oil and thermal aging. Detailed Implementation

[0018] The technical solutions in the embodiments of the present invention are clearly and completely described below. Obviously, the embodiments described are only some, not all, implementations of the present invention. Other implementations that can be obtained by those skilled in the art based on the embodiments of the present invention without creative effort all fall within the protection scope of the present invention.

[0019] It should be noted that the following quantities are by weight. There are no special restrictions on the suppliers of any of the raw materials involved in this invention. Exemplary examples include: 50 nm particle size of silica; CAS number 2530-83-8 for 3-glycidyl etheroxypropyltrimethoxysilane; CAS number 51-61-6 for dopamine; fluororubber type P757; and CAS number 2224 for ethylene glycol diglycidyl ether. -15-9; CAS number for dicumyl peroxide is 80-43-3; CAS number for triallyl isocyanurate is 1025-15-6; acid scavenger is NICC5000; antioxidant is N,N'-disec-butyl-p-phenylenediamine, CAS number is 101-96-2; accelerator is zinc dibutyldithiocarbamate, CAS number is 136-23-2; tertiary amine catalyst is triethylamine, CAS number is 121-44-8. Example 1:

[0020] The preparation method of modified liquid fluororubber is as follows: (1) Weigh precipitated silica and 3-glycidoxypropyltrimethoxysilane at a mass ratio of 10:1.2; ultrasonically disperse precipitated silica in 50 parts of 70wt% ethanol aqueous solution, add 3-glycidoxypropyltrimethoxysilane and mix evenly, heat to 80℃ and stir for 5 hours to obtain epoxidized precipitated silica. Weigh out epoxidized silica and dopamine at a mass ratio of 10:0.3; ultrasonically disperse epoxidized silica in deionized water, purge with vacuum-nitrogen circulation to remove oxygen, add dopamine and mix, heat and stir to react, adjust pH to weakly acidic, wash, and obtain dopamine-modified silica. (2) 10 parts of terminal carboxyl liquid fluororubber were added to acetone and mixed evenly. 1.2 parts of ethylene glycol diglycidyl ether, 2 parts of dopamine modified silica, and 0.1 parts of tertiary amine catalyst were added and mixed. Nitrogen gas was introduced and the mixture was heated and stirred at 95°C for 10 hours. Triethylamine was neutralized by adding concentrated hydrochloric acid dropwise. Then the mixture was added to petroleum ether and stirred. After the product precipitated, the supernatant was taken out. The process was repeated three times to remove impurities. The mixture was then dried under vacuum at 50°C to obtain modified liquid fluororubber. A method for preparing an oil-resistant and anti-aging fluororubber material includes the following steps: (1) Weigh fluororubber and modified liquid fluororubber at a mass ratio of 3:1; mix the modified liquid fluororubber and fluororubber at 90°C for 3 minutes to obtain fluororubber compound; (2) Mix 20 parts of nitrile rubber at 105°C for 10 minutes, add 80 parts of fluororubber compound, continue mixing for 20 minutes, add 5 parts of acid absorber, 1.2 parts of antioxidant, and 0.8 parts of accelerator and mix for 3 minutes, add 10 parts of vulcanizing agent and mix for 2 minutes; vulcanize at 170°C and 10MPa for 30 minutes to obtain oil-resistant and anti-aging fluororubber material.

[0021] The raw materials for the vulcanizing agent include the following components: by mass, 1.8 parts triallyl isocyanurate, 4 parts dicumyl peroxide, and 5 parts ferric chloride coordination vulcanizing agent. Example 2:

[0022] The preparation method of modified liquid fluororubber is as follows: (1) Weigh precipitated silica and 3-glycidoxypropyltrimethoxysilane at a mass ratio of 10:1.2; ultrasonically disperse precipitated silica in 50 parts of 70wt% ethanol aqueous solution, add 3-glycidoxypropyltrimethoxysilane and mix evenly, heat to 80℃ and stir for 5 hours to obtain epoxidized precipitated silica. Weigh out epoxidized silica and dopamine at a mass ratio of 10:0.3; ultrasonically disperse epoxidized silica in deionized water, purge with vacuum-nitrogen circulation to remove oxygen, add dopamine and mix, heat and stir to react, adjust pH to weakly acidic, wash, and obtain dopamine-modified silica. (2) 10 parts of terminal carboxyl liquid fluororubber were added to acetone and mixed evenly. 1.2 parts of ethylene glycol diglycidyl ether, 2 parts of dopamine modified silica, and 0.1 parts of tertiary amine catalyst were added and mixed. Nitrogen gas was introduced and the mixture was heated and stirred at 95°C for 10 hours. Triethylamine was neutralized by adding concentrated hydrochloric acid dropwise. Then the mixture was added to petroleum ether and stirred. After the product precipitated, the supernatant was taken out. The process was repeated three times to remove impurities. The mixture was then dried under vacuum at 50°C to obtain modified liquid fluororubber. A method for preparing an oil-resistant and anti-aging fluororubber material includes the following steps: (1) Weigh fluororubber and modified liquid fluororubber at a mass ratio of 3:1; mix the modified liquid fluororubber and fluororubber at 90°C for 3 minutes to obtain fluororubber compound; (2) Mix 25 parts of nitrile rubber at 105°C for 10 minutes, add 75 parts of fluororubber compound, continue mixing for 20 minutes, add 5 parts of acid absorber, 1.2 parts of antioxidant, and 0.8 parts of accelerator and mix for 3 minutes, add 10 parts of vulcanizing agent and mix for 2 minutes; vulcanize at 170°C and 10MPa for 30 minutes to obtain oil-resistant and anti-aging fluororubber material; The raw materials for the vulcanizing agent include the following components: by mass, 1.8 parts triallyl isocyanurate, 4 parts dicumyl peroxide, and 5 parts ferric chloride coordination vulcanizing agent. Example 3:

[0023] The preparation method of modified liquid fluororubber is as follows: (1) Weigh precipitated silica and 3-glycidoxypropyltrimethoxysilane at a mass ratio of 10:1.2; ultrasonically disperse precipitated silica in 50 parts of 70wt% ethanol aqueous solution, add 3-glycidoxypropyltrimethoxysilane and mix evenly, heat to 80℃ and stir for 5 hours to obtain epoxidized precipitated silica. Weigh out epoxidized silica and dopamine at a mass ratio of 10:0.3; ultrasonically disperse epoxidized silica in deionized water, deoxygenate by vacuum-nitrogen circulation, add dopamine and mix, heat and stir at 80°C for 12 hours, adjust pH to weakly acidic, wash, and obtain dopamine modified silica. (2) 10 parts of terminal carboxyl liquid fluororubber were added to acetone and mixed evenly. 1.2 parts of ethylene glycol diglycidyl ether, 2 parts of dopamine modified silica, and 0.1 parts of tertiary amine catalyst were added and mixed. Nitrogen gas was introduced and the mixture was heated and stirred at 95°C for 10 hours. Triethylamine was neutralized by adding concentrated hydrochloric acid dropwise. Then the mixture was added to petroleum ether and stirred. After the product precipitated, the supernatant was taken out. The process was repeated three times to remove impurities. The mixture was then dried under vacuum at 50°C to obtain modified liquid fluororubber. A method for preparing an oil-resistant and anti-aging fluororubber material includes the following steps: (1) Weigh fluororubber and modified liquid fluororubber at a mass ratio of 3:1; mix the modified liquid fluororubber and fluororubber at 90°C for 3 minutes to obtain fluororubber compound; (2) Mix 30 parts of nitrile rubber at 105°C for 10 minutes, add 70 parts of fluororubber compound, continue mixing for 20 minutes, add 5 parts of acid absorber, 1.2 parts of antioxidant, and 0.8 parts of accelerator and mix for 3 minutes, add 10 parts of vulcanizing agent and mix for 2 minutes; vulcanize at 170°C and 10MPa for 30 minutes to obtain oil-resistant and anti-aging fluororubber material; The raw materials for the vulcanizing agent include the following components: by mass, 1.8 parts triallyl isocyanurate, 4 parts dicumyl peroxide, and 5 parts ferric chloride coordination vulcanizing agent.

[0024] Testing: The oil-resistant and anti-aging fluororubber materials prepared in Examples 1-3 were placed in an oven for thermo-oxidative aging for 72 hours at a temperature of 170℃ and a ventilation rate of 20 times / hour. They were cut according to GB528-1982. Then, the tensile strength (MPa) of the oil-resistant and anti-aging fluororubber materials before and after thermo-oxidative aging was tested according to GB / T528-2009, and the tensile strength retention rate (%) was calculated. The tensile speed was 500 mm / min. Table 1

[0025] Conclusion: Example 1 has good anti-aging properties; considering the high price of fluororubber, the final optimal solution of Example 2 was used for the following comparative experiments.

[0026] Comparative Example 1 is based on Example 2: the difference is that the terminal carboxyl group liquid fluororubber was not modified; the other operating steps are the same. A method for preparing an oil-resistant and anti-aging fluororubber material includes the following steps: (1) Weigh fluororubber and modified liquid fluororubber at a mass ratio of 3:1; mix the modified liquid fluororubber and fluororubber at 90°C for 3 minutes to obtain fluororubber compound; (2) Mix 25 parts of nitrile rubber at 105°C for 10 minutes, add 75 parts of fluororubber compound, continue mixing for 20 minutes, add 5 parts of acid absorber, 1.2 parts of antioxidant, and 0.8 parts of accelerator and mix for 3 minutes, add 10 parts of vulcanizing agent and mix for 2 minutes; vulcanize at 170°C and 10MPa for 30 minutes to obtain oil-resistant and anti-aging fluororubber material; The raw materials for the vulcanizing agent include the following components: by mass, 1.8 parts triallyl isocyanurate, 4 parts dicumyl peroxide, and 5 parts ferric chloride coordination vulcanizing agent.

[0027] Comparative Example 2 is based on Example 2: the difference is that no coordinating vulcanizing agent was added; the other operating steps are the same. The preparation method of modified liquid fluororubber is as follows: (1) Weigh precipitated silica and 3-glycidoxypropyltrimethoxysilane at a mass ratio of 10:1.2; ultrasonically disperse precipitated silica in 50 parts of 70wt% ethanol aqueous solution, add 3-glycidoxypropyltrimethoxysilane and mix evenly, heat to 80℃ and stir for 5 hours to obtain epoxidized precipitated silica. Weigh out epoxidized silica and dopamine at a mass ratio of 10:0.3; ultrasonically disperse epoxidized silica in deionized water, deoxygenate by vacuum-nitrogen circulation, add dopamine and mix, heat and stir at 80°C for 12 hours, adjust pH to weakly acidic, wash, and obtain dopamine modified silica. (2) 10 parts of terminal carboxyl liquid fluororubber were added to acetone and mixed evenly. 1.2 parts of ethylene glycol diglycidyl ether, 2 parts of dopamine modified silica, and 0.1 parts of tertiary amine catalyst were added and mixed. Nitrogen gas was introduced and the mixture was heated and stirred at 95°C for 10 hours. Triethylamine was neutralized by adding concentrated hydrochloric acid dropwise. Then the mixture was added to petroleum ether and stirred. After the product precipitated, the supernatant was taken out. The process was repeated three times to remove impurities. The mixture was then dried under vacuum at 50°C to obtain modified liquid fluororubber. A method for preparing an oil-resistant and anti-aging fluororubber material includes the following steps: (1) Weigh fluororubber and modified liquid fluororubber at a mass ratio of 3:1; mix the modified liquid fluororubber and fluororubber at 90°C for 3 minutes to obtain fluororubber compound; (2) Mix 25 parts of nitrile rubber at 105°C for 10 minutes, add 75 parts of fluororubber compound, continue mixing for 20 minutes, add 5 parts of acid absorber, 1.2 parts of antioxidant, and 0.8 parts of accelerator and mix for 3 minutes, add 10 parts of vulcanizing agent and mix for 2 minutes; vulcanize at 170°C and 10MPa for 30 minutes to obtain oil-resistant and anti-aging fluororubber material; The raw materials for the vulcanizing agent include the following components: by mass, 1.8 parts triallyl isocyanurate and 4 parts dicumyl peroxide.

[0028] Comparative Example 3: First, the epoxy-modified nanomaterials were reacted with carboxyl-terminated liquid fluororubber, and then dopamine was introduced; The preparation method of modified liquid fluororubber is as follows: (1) Weigh precipitated silica and 3-glycidoxypropyltrimethoxysilane at a mass ratio of 10:1.2; ultrasonically disperse precipitated silica in 50 parts of 70wt% ethanol aqueous solution, add 3-glycidoxypropyltrimethoxysilane and mix evenly, heat to 80℃ and stir for 5 hours to obtain epoxidized precipitated silica. (2) Disperse 2 parts of epoxidized silica in acetone by ultrasonication, add 10 parts of terminal carboxyl liquid fluororubber and mix evenly, add 0.1 parts of tertiary amine catalyst and mix, purge with nitrogen, heat and stir at 95°C for 10 hours, add concentrated hydrochloric acid to neutralize triethylamine, then add to petroleum ether and stir, after the product precipitates, take out the supernatant, repeat three times to remove impurities, and dry under vacuum at 50°C to obtain epoxidized liquid fluororubber; (3) Weigh the epoxidized liquid fluororubber and dopamine at a mass ratio of 10:0.3; ultrasonically disperse the epoxidized liquid fluororubber in a mixture of THF and methanol at a mass ratio of 7:3, deoxygenate by passing through a vacuum-nitrogen circulation operation, add dopamine and mix, heat and stir at 80°C for 12 hours, adjust the pH to weakly acidic, wash, and obtain modified liquid fluororubber. A method for preparing an oil-resistant and anti-aging fluororubber material includes the following steps: (1) Weigh fluororubber and modified liquid fluororubber at a mass ratio of 3:1; mix the modified liquid fluororubber and fluororubber at 90°C for 3 minutes to obtain fluororubber compound; (2) Mix 25 parts of nitrile rubber at 105°C for 10 minutes, add 75 parts of fluororubber compound, continue mixing for 20 minutes, add 5 parts of acid absorber, 1.2 parts of antioxidant, and 0.8 parts of accelerator and mix for 3 minutes, add 10 parts of vulcanizing agent and mix for 2 minutes; vulcanize at 170°C and 10MPa for 30 minutes to obtain oil-resistant and anti-aging fluororubber material; The raw materials for the vulcanizing agent include the following components: by mass, 1.8 parts triallyl isocyanurate, 4 parts dicumyl peroxide, and 5 parts ferric chloride coordination vulcanizing agent.

[0029] Comparative Example 4 is based on Example 2: the difference is that the amount of 3-glycidoxypropyltrimethoxysilane added is increased; The preparation method of modified liquid fluororubber is as follows: (1) Weigh precipitated silica and 3-glycidoxypropyltrimethoxysilane at a mass ratio of 3:1; ultrasonically disperse precipitated silica in 50 parts of 70wt% ethanol aqueous solution, add 3-glycidoxypropyltrimethoxysilane and mix evenly, heat to 80℃ and stir for 5 hours to obtain epoxidized precipitated silica. Weigh out epoxidized silica and dopamine at a mass ratio of 10:0.3; ultrasonically disperse epoxidized silica in deionized water, purge with vacuum-nitrogen circulation to remove oxygen, add dopamine and mix, heat and stir to react, adjust pH to weakly acidic, wash, and obtain dopamine-modified silica. (2) 10 parts of terminal carboxyl liquid fluororubber were added to acetone and mixed evenly. 1.2 parts of ethylene glycol diglycidyl ether, 2 parts of dopamine modified silica, and 0.1 parts of tertiary amine catalyst were added and mixed. Nitrogen gas was introduced and the mixture was heated and stirred at 95°C for 10 hours. Triethylamine was neutralized by adding concentrated hydrochloric acid dropwise. Then the mixture was added to petroleum ether and stirred. After the product precipitated, the supernatant was taken out. The process was repeated three times to remove impurities. The mixture was then dried under vacuum at 50°C to obtain modified liquid fluororubber. A method for preparing an oil-resistant and anti-aging fluororubber material includes the following steps: (1) Weigh fluororubber and modified liquid fluororubber at a mass ratio of 3:1; mix the modified liquid fluororubber and fluororubber at 90°C for 3 minutes to obtain fluororubber compound; (2) Mix 25 parts of nitrile rubber at 105°C for 10 minutes, add 75 parts of fluororubber compound, continue mixing for 20 minutes, add 5 parts of acid absorber, 1.2 parts of antioxidant, and 0.8 parts of accelerator and mix for 3 minutes, add 10 parts of vulcanizing agent and mix for 2 minutes; vulcanize at 170°C and 10MPa for 30 minutes to obtain oil-resistant and anti-aging fluororubber material; The raw materials for the vulcanizing agent include the following components: by mass, 1.8 parts triallyl isocyanurate, 4 parts dicumyl peroxide, and 5 parts ferric chloride coordination vulcanizing agent.

[0030] Testing: Examples 1, 2, and Comparative Examples 1-4 were treated with No. 3 aviation kerosene at 70°C for 96 hours; the change rate of mass of the oil-resistant and anti-aging fluororubber materials before and after impregnation was tested according to GB / T1690-2006 standard. Table 2

[0031] Conclusion: Comparative Example 1 is based on Example 2: the difference is that the terminal carboxyl group liquid fluororubber was not modified; this resulted in the worst compatibility between fluororubber and nitrile rubber, many gaps at the phase interface, easy penetration of oil into the matrix, severe swelling, and the largest mass change rate; Comparative Example 2 is based on Example 2: the difference is that no coordinating vulcanizing agent was added; the lack of coordinating crosslinking resulted in insufficient density of the vulcanization network, easy wetting and swelling of kerosene, and an increased mass change rate.

[0032] Comparative Example 3: First, the epoxy-modified nanomaterial was reacted with the carboxyl-terminated liquid fluororubber, and then dopamine was introduced. This resulted in increased steric hindrance and a lower content of introduced dopamine compared to the original, thus worsening the coordination effect with the coordinating vulcanizing agent. Consequently, the crosslinking density decreased, leading to an increase in the mass change rate.

[0033] Comparative Example 4 is based on Example 2: the difference is that the amount of 3-glycidyl etheroxypropyltrimethoxysilane added is increased; the excessive coupling agent on the nanomaterial increases the steric hindrance, which affects the binding with dopamine and terminal carboxyl liquid fluororubber, thus leading to a decrease in performance.

[0034] It will be apparent to those skilled in the art that the present invention is not limited to the specific details of the exemplary embodiments described above, and that the present invention can be implemented in other specific forms without departing from the spirit and core features of the invention. Therefore, the above embodiments should be considered exemplary rather than restrictive in any respect. The scope of protection of the present invention is defined by the appended claims, not by the foregoing description, and is therefore intended to encompass all variations in the meaning and scope of the equivalents of the claims within the scope of the present invention.

Claims

1. A method for preparing an oil-resistant and anti-aging fluororubber material, characterized in that: The following steps are included: (1) Modified liquid fluororubber and fluororubber are mixed to obtain fluororubber compound; (2) Mix nitrile rubber, add fluororubber compound, continue mixing, add acid absorber, antioxidant and accelerator; add vulcanizing agent and mix, vulcanize, to obtain oil-resistant and anti-aging fluororubber material; The mass ratio of the fluororubber to the modified liquid fluororubber is (2~3):1; the raw materials of the oil-resistant and anti-aging fluororubber material include the following components: by mass parts, 20~35 parts nitrile rubber, 70~80 parts fluororubber compound, 7~10 parts vulcanizing agent, 4~7 parts acid absorber, 1~2 parts antioxidant, and 0.8~1.5 parts accelerator.

2. The method for preparing an oil-resistant and anti-aging fluororubber material according to claim 1, characterized in that: The preparation method of the modified liquid fluororubber is as follows: (1) Disperse silica in an ethanol aqueous solution by ultrasonication, add 3-glycidoxypropyltrimethoxysilane and mix evenly, heat and stir to obtain epoxidized silica; disperse epoxidized silica in deionized water by ultrasonication, remove oxygen by vacuum-nitrogen circulation, add dopamine and mix, heat and stir to react, adjust pH to weak acidity, wash to obtain dopamine modified silica; (2) Add the carboxyl-terminated liquid fluororubber to tetrahydrofuran and mix evenly. Add ethylene glycol diglycidyl ether, dopamine-modified silica, and tertiary amine catalyst and mix. Heat and stir for 4 to 8 hours to obtain modified liquid fluororubber.

3. The method for preparing an oil-resistant and anti-aging fluororubber material according to claim 2, characterized in that: The mass ratio of the silica to 3-glycidoxypropyltrimethoxysilane is 10:(1~2); the mass ratio of the epoxidized silica to dopamine is 10:(0.3~0.7).

4. The preparation method of an oil-resistant and anti-aging fluororubber material according to claim 2, characterized in that: The modified liquid fluororubber raw materials include the following components: by mass, 10 parts of carboxyl-terminated liquid fluororubber, 0.5-1.5 parts of ethylene glycol diglycidyl ether, 1-2 parts of dopamine-modified silica, and 0.05-0.12 parts of tertiary amine catalyst.

5. The method for preparing an oil-resistant and anti-aging fluororubber material according to claim 1, characterized in that: The mixing temperature is 90~115℃, and the mixing time is 20~40 minutes; the vulcanization process conditions are: temperature 150~175℃, pressure 7~15MPa, and time 15~30 minutes.

6. The method for preparing an oil-resistant and anti-aging fluororubber material according to claim 1, characterized in that: The raw materials of the vulcanizing agent include the following components: by mass parts, 1-2 parts triallyl isocyanurate, 3-6 parts dicumyl peroxide, and 5-10 parts coordination vulcanizing agent.

7. The method for preparing an oil-resistant and anti-aging fluororubber material according to claim 6, characterized in that: The coordinating sulfide includes one or more of ferric chloride, copper chloride, and zinc chloride.

8. The oil-resistant and anti-aging fluororubber material prepared by the preparation method of the oil-resistant and anti-aging fluororubber material according to any one of claims 1 to 7.

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