High-temperature-resistant perfluoroether rubber as well as preparation method and application thereof

Abstract

The invention discloses high-temperature-resistant perfluoroether rubber as well as a preparation method and application thereof, and belongs to the technical field of fluororubber materials. The invention provides a fluoride-free surfactant for preparing high-temperature-resistant perfluoroether rubber. Perfluoroether rubber prepared from the fluorine-free surfactant has excellent mechanical properties and thermal aging resistance, has the same performance as fluororubber synthesized by using perfluorooctanoic acid surfactant, and has the potential of replacing the perfluorooctanoic acid surfactant. The fluorine-free surfactant disclosed by the invention avoids the harm of the traditional fluorine-containing surfactant to the environment and human health; the price is low and industrial production is easy; by adopting a high-pressure emulsion polymerization technology, a stable emulsion can be obtained, the polymerization reaction is favorably controlled, and the preparation method has a good application prospect.

Description

Technical Field

[0001] The present invention belongs to the technical field of fluororubber materials, and particularly relates to a high-temperature resistant perfluoroether rubber and its preparation method and use. Background Art

[0002] Perfluoroether rubber (FFKM) is a special rubber polymerized from perfluoroether monomers, which has excellent high-temperature resistance, chemical corrosion resistance, oil resistance and solvent resistance, and is widely used in high-end fields such as aerospace, petrochemical industry, and semiconductor. However, in the preparation process of traditional FFKM, fluorosurfactants such as ammonium perfluorooctanoate (PFOA) and perfluorooctane sulfonic acid (PFOS) are usually required. These fluorosurfactants have environmental persistence, bioaccumulation and toxicity, and will cause serious harm to the environment and human health.

[0003] At present, there have been some reports on the preparation of FFKM without fluorosurfactants. For example, using hydrocarbon surfactants, sodium alkyl sulfate, sodium alkyl benzene sulfonate, etc. However, the emulsifying effect of these surfactants is poor, and it is difficult to obtain a stable emulsion, resulting in difficult control of the polymerization reaction, wide molecular weight distribution of the product, and poor performance. Using silicone surfactant: for example, polyether-modified silicone oil, etc. Although these surfactants have a good emulsifying effect, they are expensive and difficult to realize industrial application.

[0004] Therefore, it is of great practical significance to develop a method for preparing FFKM with a fluorine-free surfactant that is efficient, environmentally friendly and low-cost. Summary of the Invention

[0005] In order to solve the above problems existing in the prior art, the purpose of the present invention is to provide a high-temperature resistant perfluoroether rubber and its preparation method and use.

[0006] In order to achieve the above purpose, the present invention adopts the following technical scheme:

[0007] The present invention provides a fluorine-free surfactant, which is prepared from an alcohol compound, a hydroxy-containing haloalkyl sulfonate and a basic reagent, and the mass ratio of the alcohol compound, the hydroxy-containing haloalkyl sulfonate and the basic reagent is (10-30):(10-40):(10-30).

[0008] Further, the mass ratio of the alcohol compound, the hydroxy-containing haloalkyl sulfonate and the basic reagent is 20:25:20; the alcohol compound is R-OH, and R is selected from C 2-6 alkyl, the hydroxy-containing haloalkyl sulfonate is sodium hydroxy-containing haloalkyl sulfonate, and the basic reagent is at least one of NaH, CaH2, KH, and n-butyllithium.

[0009] In the present invention, C 2-6 The alkyl group includes a linear or branched alkyl group having 2 to 6 carbon atoms.

[0010] Furthermore, the alcohol compound is 2-methyl-1-pentanol, the sodium halohydroxyalkylsulfonate is sodium 3-chloro-2-hydroxypropanesulfonate, and the basic reagent is NaH.

[0011] The present invention also provides a preparation method of the above-mentioned fluorine-free surfactant, and the preparation method is as follows:

[0012] (1) React the alcohol compound with the basic reagent;

[0013] (2) After the reaction in step (1) is completed, add the halohydroxyalkylsulfonate containing a hydroxyl group and react to obtain the fluorine-free surfactant.

[0014] Furthermore, the conditions of the reaction in step (1) are under the protection of an inert medium, the solvent of the reaction is tetrahydrofuran, the temperature of the reaction is -10 to 15 °C, and the time of the reaction is 0.2 to 5 h;

[0015] The conditions of the reaction in step (2) are under the protection of an inert medium, the temperature of the reaction is -10 to 15 °C, and the time of the reaction is 10 to 40 h.

[0016] Furthermore, the inert medium in step (1) is nitrogen, the temperature of the reaction is 0 to 5 °C, and the time of the reaction is 1 h;

[0017] The inert medium in step (2) is nitrogen, the temperature of the reaction is 0 to 5 °C, and the time of the reaction is 24 h.

[0018] The present invention also provides a perfluoroether rubber, which is prepared from perfluoroether rubber raw rubber, a vulcanizing agent, an accelerator, a filler, and an internal mold release agent; the mass ratio of the perfluoroether rubber raw rubber, the vulcanizing agent, the accelerator, the filler, and the internal mold release agent is (50 to 200):(0.1 to 10):(0.1 to 10):(5 to 50):(0.1 to 10);

[0019] The perfluoroether rubber raw rubber is prepared from the above-mentioned fluorine-free surfactant, a mixed monomer, an initiator, and a chain transfer agent, and the mass ratio of the fluorine-free surfactant, the mixed monomer, the initiator, and the chain transfer agent is (1 to 50):(100 to 300):(1 to 20):(0.1 to 10); the mixed monomer is perfluoromethyl vinyl ether, tetrafluoroethylene, and I(CF2)2OCF=CF2.

[0020] Further, the mass ratio of the perfluoroether rubber raw rubber, vulcanizing agent, accelerator, filler, and internal mold release agent is 100:3:1:18:1;

[0021] The mass ratio of the fluorine-free surfactant, mixed monomers, initiator, and chain transfer agent is (8 - 20):200:8:1;

[0022] The molar ratio of the perfluoromethyl vinyl ether, tetrafluoroethylene, and I(CF2)2OCF=CF2 is (5 - 50):(50 - 200):1; the initiator is at least one of diisopropyl peroxydicarbonate, dicyclohexyl peroxydicarbonate, tert-butyl peroxyneopentanoate, and azobisisobutyronitrile, and the chain transfer agent is at least one of diiodomethane, 1,2-diiodoethane, perfluorohexyl iodide, perfluorobutyl iodide, and 1,4-diiodooctafluorobutane;

[0023] The vulcanizing agent is at least one of triallyl isocyanurate, trimethylolpropane trimethacrylate, pentaerythritol tetraacrylate, and m-phenylene bismaleimide; the accelerator is at least one of 2,5-di-tert-butylperoxy-2,5-dimethylhexane, dicumyl peroxide, bis(tert-butylperoxyisopropyl)benzene, and benzoyl peroxide, the filler is carbon black, and the internal mold release agent is a fluorinated polyether derivative;

[0024] Further, the molar ratio of the perfluoromethyl vinyl ether, tetrafluoroethylene, and I(CF2)2OCF=CF2 is (13.5 - 38.5):(85.5 - 110.5):1; the initiator is diisopropyl peroxydicarbonate, and the chain transfer agent is diiodomethane;

[0025] The vulcanizing agent is triallyl isocyanurate, and the accelerator is 2,5-di-tert-butylperoxy-2,5-dimethylhexane.

[0026] The present invention also provides a preparation method of the above perfluoroether rubber, and the preparation method is as follows:

[0027] (1) React the fluorine-free surfactant, mixed monomers with the initiator, add the chain transfer agent, and continue the reaction to obtain the perfluoroether rubber raw rubber;

[0028] The reaction time is 0.5 - 5 h, the reaction pressure is 1.0 - 10.0 MPa, and the reaction temperature is 50 - 120 °C;

[0029] The time for continuing the reaction is 5 - 20 h, the reaction pressure is 1.0 - 10.0 MPa, and the reaction temperature is 50 - 120 °C.

[0030] (2) The perfluoroether rubber raw rubber obtained in step (1) is subjected to thin-pass plasticizing for 1 to 5 times, and a promoter, a filler, and an internal mold release agent are added, followed by mixing. Then, a vulcanizing agent is added for mixing, and after aging and remilling, perfluoroether rubber is obtained.

[0031] The mixing is carried out by thin-pass plasticizing for 1 to 10 times, the aging time is 10 to 30 h, and the remilling is carried out by thin-pass plasticizing for 1 to 10 times.

[0032] Further, in step (1), the reaction time is 1.5 h, the reaction pressure is 3.0 MPa, and the reaction temperature is 75 - 85 °C;

[0033] The time for the continued reaction is 10.5 h, the reaction pressure is 3.0 MPa, and the reaction temperature is 75 - 85 °C.

[0034] In step (2), the mixing is carried out by thin-pass plasticizing for 5 times, the aging time is 16 h, and the remilling is carried out by thin-pass plasticizing for 5 times.

[0035] The present invention also provides the use of the above-mentioned fluorine-free surfactant and perfluoroether rubber in the preparation of rubber materials.

[0036] The present invention has achieved the following beneficial effects:

[0037] The present invention provides a fluorine-free surfactant for the preparation of high-temperature resistant perfluoroether rubber. The perfluoroether rubber prepared with the fluorine-free surfactant of the present invention has excellent mechanical properties and heat aging resistance, and is comparable to the performance of fluororubber synthesized with perfluorooctanoic acid-based surfactants, having the potential to replace perfluorooctanoic acid-based surfactants. The fluorine-free surfactant of the present invention avoids the harm of traditional fluorine-containing surfactants to the environment and human health; it is inexpensive and easy to industrialize; by using the high-pressure emulsion polymerization technology, a stable emulsion can be obtained, which is beneficial to controlling the polymerization reaction and has good application prospects.

[0038] Obviously, based on the above content of the present invention, according to the common technical knowledge and conventional means in the art, without departing from the above basic technical idea of the present invention, various other forms of modifications, substitutions or changes can be made.

[0039] The above content of the present invention will be further described in detail below through specific embodiments in the form of examples. However, this should not be construed as limiting the scope of the above subject matter of the present invention to the following examples. All technologies implemented based on the above content of the present invention fall within the scope of the present invention. Specific Embodiments

[0040] The raw materials and equipment used in the present invention are all known products, obtained by purchasing commercially available products.

[0041] The parts in this embodiment are all parts by mass.

[0042] In the following experiments, if the temperature is not specified, the reaction is carried out under normal temperature conditions. Normal temperature means room temperature, which is 25 ± 5°C.

[0043] The preparation process of the fluorine-free surfactant is as follows:

[0044]

[0045] where R1 is CH3(CH2) n —, n is an integer from 0 to 1; R2 is CH3(CH2) m —, m is an integer from 0 to 3; preferably, R1 is CH3— and R2 is CH3(CH2)2—.

[0046] Example 1: Preparation of perfluoroether rubber raw rubber I

[0047] 1. Preparation of fluorine-free surfactant

[0048] Add 20 parts of 2-methyl-1-pentanol into the reaction kettle, introduce nitrogen, and after replacing the nitrogen, add 120 parts of tetrahydrofuran. Then, under stirring conditions, control the temperature at 0 - 5°C, add 20 parts of sodium hydride, and after reacting for 1 h, add 25 parts of 3-chloro-2-hydroxypropanesulfonic acid sodium salt, and keep the nitrogen atmosphere for reaction for 24 h. After the reaction is completed, distill off the tetrahydrofuran, then dissolve the obtained product in 15 parts of distilled water and extract it with 20 parts of petroleum ether. The aqueous phase is subjected to vacuum distillation to obtain the fluorine-free surfactant.

[0049] 2. Preparation of perfluoroether rubber raw rubber I

[0050] Add 30 L of deionized water and a 50 g / L aqueous solution of the fluorine-free surfactant obtained in Step 1 containing 900 g of the fluorine-free surfactant into the reaction kettle. First, displace the air in the vapor space of the reaction kettle with nitrogen, and then displace it with a mixed monomer (perfluoromethyl vinyl ether: tetrafluoroethylene: I(CF2)2OCF=CF2 is 19.8:79.4:0.8, mol%), so that the oxygen content is less than 10 ppm. Heat the reaction kettle to 85 °C. Continuously add the mixed monomer into the reaction kettle with a diaphragm compressor to increase the pressure to 3.0 MPa. Start stirring to fully mix the mixed monomer in the reaction kettle (i.e., stir and mix for 30 min), and then add 600 g of an aqueous initiator solution (50 g / L, the initiator is diisopropyl peroxydicarbonate) to start the reaction. During the reaction, continuously replenish the mixed monomer (perfluoromethyl vinyl ether: tetrafluoroethylene: I(CF2)2OCF=CF2 is 19.8:79.4:0.8, mol%) to maintain the pressure in the reaction kettle at 3.0 MPa and the temperature at 75 °C. After reacting for 1.5 h, add 75 g of the chain transfer agent diiodomethane. Then continue the reaction until the predetermined feeding amount of the mixed monomer reaches 15 kg. After reacting for 12 h (starting from the addition of the initiator), end the reaction to obtain the perfluoroether rubber raw rubber I.

[0051] Example 2: Preparation of perfluoroether rubber raw rubber II

[0052] Refer to the preparation method of Example 1, with the only difference being that the mixed monomer (perfluoromethyl vinyl ether: tetrafluoroethylene: I(CF2)2OCF=CF2 is 19.8:79.4:0.8, mol%) is replaced with a mixed monomer (perfluoromethyl vinyl ether: tetrafluoroethylene: I(CF2)2OCF=CF2 is 10.8:88.4:0.8, mol%) to obtain the perfluoroether rubber raw rubber II.

[0053] Example 3: Preparation of perfluoroether rubber raw rubber III

[0054] Refer to the preparation method of Example 1, with the only difference being that the mixed monomer (perfluoromethyl vinyl ether: tetrafluoroethylene: I(CF2)2OCF=CF2 is 19.8:79.4:0.8, mol%) is replaced with a mixed monomer (perfluoromethyl vinyl ether: tetrafluoroethylene: I(CF2)2OCF=CF2 is 30.8:68.4:0.8, mol%) to obtain the perfluoroether rubber raw rubber III.

[0055] Example 4: Preparation of perfluoroether rubber raw rubber IV

[0056] The preparation method of Example 1 is referred to, except that the 50 g / L fluorine-free surfactant aqueous solution containing 900 g of the fluorine-free surfactant obtained in step 1 is replaced by a 50 g / L fluorine-free surfactant aqueous solution containing 600 g of the fluorine-free surfactant obtained in step 1; the mixed monomer (perfluoromethyl vinyl ether: tetrafluoroethylene: I(CF2)2OCF=CF2 is 19.8:79.4:0.8, mol%) is replaced by a mixed monomer (perfluoromethyl vinyl ether: tetrafluoroethylene: I(CF2)2OCF=CF2 is 10.8:88.4:0.8, mol%) to obtain perfluoroether rubber raw rubber IV.

[0057] Example 5: Preparation of perfluoroether rubber raw rubber V

[0058] The preparation method of Example 1 is referred to, except that the 50 g / L fluorine-free surfactant aqueous solution containing 900 g of the fluorine-free surfactant obtained in step 1 is replaced by a 50 g / L fluorine-free surfactant aqueous solution containing 1.5 kg of the fluorine-free surfactant obtained in step 1; the mixed monomer (perfluoromethyl vinyl ether: tetrafluoroethylene: I(CF2)2OCF=CF2 is 19.8:79.4:0.8, mol%) is replaced by a mixed monomer (perfluoromethyl vinyl ether: tetrafluoroethylene: I(CF2)2OCF=CF2 is 10.8:88.4:0.8, mol%) to obtain perfluoroether rubber raw rubber V.

[0059] Example 6: Preparation of perfluoroether rubber I

[0060] Weigh 100 parts (mass parts) of the perfluoroether rubber raw rubber I obtained in Example 1, 3 parts of the vulcanizing agent triallyl isocyanurate TAIC, 1 part of the accelerator 2,5-di-tert-butyl peroxide-2,5-dimethylethane, 18 parts of the filler carbon black N990, and 1 part of the internal release agent fluorinated polyether derivative (article number: FPA-1, purchased from Solvay (Shanghai) Co., Ltd.) for use.

[0061] The weighed perfluoroether rubber raw rubber I was thinly plasticized 3 times on a double-roll open mill at room temperature. Then, the accelerator, filler, and internal mold release agent were added and mixed thoroughly, and then the vulcanizer was added and mixed thoroughly to form a sheet. The mixing operation is: thinly plasticized 5 times on a double-roll open mill at room temperature. After aging for 16 hours, the sheet was re-refined to obtain perfluoroether rubber I. The re-refining operation is: thinly plasticized 5 times on a double-roll open mill at room temperature.

[0062] Example 7: Preparation of perfluoroether rubber II

[0063] Referring to the preparation method of Example 6, the only difference is that the perfluoroether rubber raw rubber I is replaced by the perfluoroether rubber raw rubber II obtained in Example 2 to prepare perfluoroether rubber II.

[0064] Example 8: Preparation of perfluoroether rubber III

[0065] Referring to the preparation method of Example 6, the only difference is that the perfluoroether rubber raw rubber I is replaced with the perfluoroether rubber raw rubber III obtained in Example 3 to prepare perfluoroether rubber III.

[0066] Example 9: Preparation of perfluoroether rubber IV

[0067] Referring to the preparation method of Example 6, the only difference is that the perfluoroether rubber raw rubber I is replaced with the perfluoroether rubber raw rubber IV obtained in Example 4 to prepare high-temperature resistant perfluoroether rubber IV.

[0068] Example 10: Preparation of perfluoroether rubber V

[0069] Referring to the preparation method of Example 6, the only difference is that the perfluoroether rubber raw rubber I is replaced with the perfluoroether rubber raw rubber V obtained in Example 5 to prepare perfluoroether rubber V.

[0070] The following is the preparation method of the control sample.

[0071] Comparative Example: Preparation of perfluoroether rubber VI

[0072] 1. Preparation of perfluoroether rubber raw rubber VI: Referring to the preparation method of Example 2, the only difference is that ammonium perfluorooctanoate is used as the surfactant to obtain perfluoroether rubber raw rubber VI.

[0073] 2. Preparation of perfluoroether rubber VI: Referring to the preparation method of Example 6, the only difference is that the perfluoroether rubber raw rubber I is replaced with the perfluoroether rubber raw rubber VI obtained in step 1 to prepare perfluoroether rubber VI.

[0074] The beneficial effects of the present invention are demonstrated by the following experimental examples.

[0075] Experimental Example 1: Properties of the perfluoroether rubber of the present invention

[0076] The perfluoroether rubbers prepared in Examples 6 - 10 and the comparative example were subjected to performance tests, and the test method standards are as follows:

[0077] The test method standard for F content is: BSEN14582 - 2016.

[0078] The test method standard for mechanical properties is: GB / T30308 - 2013.

[0079] The test method standard for compression set rate is: GB / T30308 - 2013.

[0080] Table 1 Mechanical properties and heat aging properties of the perfluoroether rubber of the present invention

[0081]

[0082]

[0083] The results are shown in Table 1. Comparing the perfluoroether rubbers prepared in Examples 6-10 of the present invention, the perfluoroether rubber III prepared in Example 8 has excellent mechanical properties and heat aging properties, comparable to those of the comparative example.

[0084] Furthermore, the perfluoroether rubber III prepared in Example 8 and the perfluoroether rubber VI prepared in the comparative example were tested for the content of perfluoro- and polyfluoroalkyl substances (PFAS). The results are shown in Table 2. Test method: Analyzed by LC-MS according to the standards EN17681-1:2022 and EN17681-2:2022.

[0085] Table 2 Detection of the content of perfluoro- and polyfluoroalkyl substances (PFAS)

[0086]

[0087]

[0088]

[0089] Where MDL = method detection limit; ND = not detected (<MDL); "-" = not detected.

[0090] From the PFAS content test results, it can be seen that high-concentration PFHxA can be extracted from the perfluoroether rubber VI prepared in the comparative example, while the PFHxA content in the perfluoroether rubber III prepared in Example 8 is <1 ppm, meeting the environmental protection and green concept.

[0091] In summary, the present invention provides a fluorine-free surfactant for preparing high-temperature resistant perfluoroether rubber. The perfluoroether rubber prepared with the fluorine-free surfactant of the present invention has excellent mechanical properties and heat aging properties, comparable to those of the fluororubber synthesized using perfluorooctanoic acid-based surfactants, and has the potential to replace perfluorooctanoic acid-based surfactants. The fluorine-free surfactant of the present invention avoids the harm of traditional fluorine-containing surfactants to the environment and human health; it is inexpensive and easy to industrialize; by using the high-pressure emulsion polymerization technology, a stable emulsion can be obtained, which is beneficial to controlling the polymerization reaction and has good application prospects.

Claims

1. A fluorine-free surfactant, characterized in that: The fluorine-free surfactant is prepared using an alcohol compound, a hydroxyl-containing halogenated alkyl sulfonate and an alkaline agent as raw materials, wherein the mass ratio of the alcohol compound, the hydroxyl-containing halogenated alkyl sulfonate and the alkaline agent is (10-30):(10-40): (10～30)。 2. The fluorine-free surfactant according to claim 1, characterized in that: The mass ratio of the alcohol compound, the hydroxyl-containing halogenated alkyl sulfonate and the alkaline reagent is 20:25:20; the alcohol compound is R-OH, R is selected from C 2-6 The alkyl group is a hydroxyl group, the hydroxyl-containing halogenated alkyl sulfonate is a hydroxyl-containing sodium halogenated alkyl sulfonate, and the alkaline agent is at least one of NaH, CaH2, KH, and n-butyl lithium; preferably, the alcohol compound is 2-methyl 1-pentanol, the hydroxyl-containing sodium halogenated alkyl sulfonate is sodium 3-chloro 2-hydroxypropane sulfonate, and the alkaline agent is NaH.

3. The method for preparing the fluorine-free surfactant according to claim 1 or 2, characterized in that: The preparation method is as follows: (1) Alcohol compounds react with alkaline reagents; (2) After the reaction in step (1) is completed, a hydroxyl-containing halogenated alkyl sulfonate is added to react to obtain a fluorine-free surfactant.

4. The preparation method according to claim 3, characterized in that: The reaction conditions in step (1) are inert medium protection, the reaction solvent is tetrahydrofuran, the reaction temperature is -10 to 15°C, and the reaction time is 0.2 to 5h; The reaction conditions in step (2) are inert medium protection, the reaction temperature is -10 to 15°C, and the reaction time is 10 to 40 hours.

5. The preparation method according to claim 4, characterized in that: In step (1), the inert medium is nitrogen, the reaction temperature is 0-5°C, and the reaction time is 1h; In step (2), the inert medium is nitrogen, the reaction temperature is 0-5° C., and the reaction time is 24 h.

6. A perfluoroether rubber, characterized in that: The perfluoroether rubber is prepared from perfluoroether rubber raw rubber, a vulcanizing agent, an accelerator, a filler and an internal mold release agent as raw materials; the mass ratio of the perfluoroether rubber raw rubber, the vulcanizing agent, the accelerator, the filler and the internal mold release agent is (50-200):(0.1-10):(0.1-10):(5-50):(0.1-10); The perfluoroether rubber raw rubber is prepared using the fluorine-free surfactant, mixed monomer, initiator and chain transfer agent as described in claim 1 or 2 as raw materials, and the mass ratio of the fluorine-free surfactant, mixed monomer, initiator and chain transfer agent is (1-50):(100-300):(1-20):(0.1-10); the mixed monomer is perfluoromethyl vinyl ether, tetrafluoroethylene and I(CF2)2OCF=CF2.

7. The perfluoroether rubber according to claim 6, characterized in that: The mass ratio of the perfluoroether rubber raw rubber, the vulcanizing agent, the accelerator, the filler and the internal release agent is 100:3:1:18:1; The mass ratio of the fluorine-free surfactant, the mixed monomer, the initiator and the chain transfer agent is (8-20):200:8:1; The molar ratio of the perfluoromethyl vinyl ether, tetrafluoroethylene and I(CF2)2OCF=CF2 is (5-50):(50-200):1; the initiator is at least one of diisopropyl peroxydicarbonate, dicyclohexyl peroxydicarbonate, tert-butyl peroxypivalate and azobisisobutyronitrile; the chain transfer agent is at least one of diiodomethane, 1,2-diiodoethane, perfluorohexyl iodide, perfluorobutyl iodide and 1,4-diiodooctafluorobutane; The vulcanizing agent is at least one of triallyl isocyanurate, trimethylolpropane trimethacrylate, pentaerythritol tetraacrylate, and metaphenylene bismaleimide; the accelerator is at least one of 2,5-di-tert-butylperoxy-2,5-dimethylethane, diisopropyl peroxide, bis(tert-butylperoxyisopropyl)benzene, and benzoyl peroxide; the filler is carbon black; and the internal mold release agent is a fluorinated polyether derivative; Preferably, the molar ratio of the perfluoromethyl vinyl ether, tetrafluoroethylene and I(CF2)2OCF=CF2 is (13.5-38.5):(85.5-110.5):1; the initiator is diisopropyl peroxydicarbonate, and the chain transfer agent is diiodomethane; The vulcanizing agent is triallyl isocyanurate, and the accelerator is 2,5-di-tert-butylperoxy-2,5-dimethylethane.

8. The method for preparing the perfluoroether rubber according to claim 6 or 7, characterized in that: The preparation method is as follows: (1) reacting a fluorine-free surfactant, a mixed monomer and an initiator, adding a chain transfer agent, and continuing the reaction to obtain a perfluoroether rubber raw rubber; The reaction time is 0.5 to 5 hours, the reaction pressure is 1.0 to 10.0 MPa, and the reaction temperature is 50 to 120° C.; The reaction time is 5 to 20 hours, the reaction pressure is 1.0 to 10.0 MPa, and the reaction temperature is 50 to 120°C. (2) thinly refining the raw perfluoroether rubber obtained in step (1) for 1 to 5 times, adding an accelerator, a filler, and an internal mold release agent, mixing, and then adding a vulcanizing agent, mixing, aging, and refining to obtain a perfluoroether rubber; The mixing is thin-pass mastication for 1 to 10 times, the aging time is 10 to 30 hours, and the re-milling is thin-pass mastication for 1 to 10 times.

9. The preparation method according to claim 8, characterized in that: The reaction time in step (1) is 1.5 h, the reaction pressure is 3.0 MPa, and the reaction temperature is 75-85° C.; The reaction time is 10.5 hours, the reaction pressure is 3.0 MPa, and the reaction temperature is 75-85°C. The mixing in step (2) is thin-pass plasticizing for 5 times, the aging time is 16 hours, and the re-mixing is thin-pass plasticizing for 5 times.

10. Use of the fluorine-free surfactant according to claim 1 or 2 and the perfluoroether rubber according to claim 6 or 7 in the preparation of rubber materials.

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