Fluorine-containing monomer, fluorine-containing silicone rubber and preparation method thereof

Abstract

The invention relates to the technical field of polymer synthesis, and particularly discloses a fluorine-containing monomer, fluorine-containing silicone rubber and a preparation method of the fluorine-containing monomer, the structure of the fluorine-containing monomer contains # imgabs 0 # bonds or # imgabs 1 #, and the fluorine-containing monomer can be introduced into the structure of ethyl silicone rubber, so that the aging resistance and mechanical properties of rubber are improved; the invention also discloses the fluorine-containing silicone rubber prepared by introducing the fluorine-containing monomer into the structure of the ethyl silicone rubber, and the fluorine-containing silicone rubber has better aging resistance and mechanical properties.

Description

Technical Field

[0001] The invention relates to the technical field of polymer synthesis, and in particular to a fluorine-containing monomer, a fluorine-containing silicone rubber and a preparation method thereof. Background Art

[0002] According to the requirements of space environment, polar cold environment and hydrogen fuel cell field for low temperature performance of materials, rubber products must maintain elasticity and sealing performance at ultra-low temperature. At present, only silicone rubber can meet such demanding service requirements, especially for low temperature environment <-100℃, only ethyl silicone rubber can be used for a long time. Ethyl silicone rubber is a polymethylsiloxane side chain methyl replaced by ethyl. When all side chains are ethyl, the glass transition temperature Tg is as low as -145℃. Therefore, polydiethylsiloxane is considered to be the rubber with the most outstanding low temperature performance, but it crystallizes at around -73℃ and undergoes a crystal phase transition at -10~20℃, causing the material to harden at low temperature and unable to exert its low temperature resistance. The key factors restricting the low temperature resistance of silicone rubber products are the glass transition temperature and crystallinity of raw rubber. In order to improve the crystallization behavior of polydiethylsiloxane, other copolymer units are introduced into the main chain of the molecule to destroy its chain regularity and thus destroy its crystallinity.

[0003] Studies have shown that when the molar fraction of ethyl is 10%, the regular structure of polymethylsiloxane can be destroyed, and the crystallization temperature is significantly reduced, but the crystallization does not completely disappear. When the molar number of ethyl is 20%, 30%, and 40%, there is no crystallization melting transition in the range of -150 to 0°C, and Tg is -140, -143, -145, and -146°C, respectively, that is, as the ethyl chain content increases, the glass transition temperature decreases. For the compression cold resistance coefficient, when the molar fraction of ethyl chain is 10%, the compression cold resistance coefficient of ethyl silicone rubber at -80 and -100°C is 0.45 and 0.19, respectively, and as the ethyl chain content increases, the low temperature resistance improves. When the molar fraction of ethyl chain increases to 20%, the compression cold resistance coefficient at -80 and -100°C reaches 0.76 and 0.47, respectively, showing a more excellent low temperature resistance; as the ethyl chain content further increases, the low temperature resistance does not change significantly. It can be seen that the introduction of ethyl chain greatly improves the cold resistance of silicone rubber. However, the hot air aging test shows that after 100℃×72h hot air aging, the mechanical properties of ethyl silicone rubber with ethyl chain mole fraction of 10% and 20% do not change much, but the mechanical properties of ethyl silicone rubber with ethyl chain mole fraction of 30% show a significant decrease, and when the ethyl chain is 40%, the mechanical properties of ethyl silicone rubber decrease significantly; after 150℃×72h hot air aging, it shows a similar trend of change, among which the silicone rubber vulcanizate with ethyl chain mole fraction of 40% becomes brittle, because the ethyl side chain is more easily oxidized and broken in a hot oxygen environment, resulting in reduced thermal aging performance. Therefore, the preparation of low-temperature resistant silicone rubber, while taking into account excellent aging resistance and mechanical properties, still faces great challenges. Summary of the invention

[0004] In view of the above problems, the first object of the present invention is to provide a fluorine-containing monomer, which can be introduced into the structure of ethyl silicone rubber, thereby improving the aging resistance and mechanical properties of the rubber.

[0005] The second object of the present invention is to provide a method for preparing the above-mentioned fluorine-containing monomer.

[0006] The third object of the present invention is to provide a method for preparing the above-mentioned fluorine-containing silicone rubber.

[0007] The fourth object of the present invention is to provide fluorine-containing silicone rubber obtained by the above-mentioned method for preparing fluorine-containing silicone rubber.

[0008] The first technical solution adopted by the present invention is: a fluorine-containing monomer, including one of the following compounds:

[0009]

[0010] Wherein, R1 and R2 are H or a substituent having less than 8 carbon atoms; R is one of CH3-CH(F)-CH2-, CH3-CH(F)CH2CH2- and Ph-CH2-CH(F)-CH3; R4 and R5 are a substituent containing -Si(OEt)2-, a substituent having a straight chain or branched structure and a carbon-carbon double bond having ≤12 carbon atoms, and a terminal substituent containing One of the substituents of the bond; R6 is a linear alkyl substituent; R7 is

[0011]

[0012] Preferably, R1 and R2 are one of methyl, ethyl, propyl, isopropyl and phenyl.

[0013] Preferably, the substituent containing -Si(OEt)2- is R1Si(OEt)2-;

[0014] The substituent having a straight chain or branched structure of the carbon-carbon double bond with a carbon number of ≤12 is CH2=CHCH2-, CH2=CHCH(CH3)-, CH2=CHCH2CH2-, CH2=CHC(CH3) 2- , one of CH2=CHCH2CH2CH2-, CH2=CHCH2CH2CH2CH2-, CH2=C(CH3)CH2CH2-, CH2=C(CH2CH3)CH2CH2- and CH2=CHCH(Ph)-;

[0015] The end contains The substituent of the bond is one of R1R2SiH-, R1SiH2- and R1SiHCl-;

[0016] Wherein, R1 and R2 are one of methyl, ethyl, propyl, isopropyl and phenyl.

[0017] Preferably, R6 is one of methyl, ethyl, propyl and butyl.

[0018] The second technical solution adopted by the present invention is: a method for preparing a fluorine-containing monomer as described in the first technical solution, comprising: synthesizing fluorine-containing monomers as shown in chemical formulas A1 to A6 and A12 by using silane and Grignard reagent; synthesizing fluorine-containing monomers as shown in chemical formula A7 by using Chen reagent; synthesizing fluorine-containing monomers as shown in chemical formula A8 by using FLUOLEAD reagent; and synthesizing fluorine-containing monomers as shown in chemical formula A9 by exchange method.

[0019] The third technical solution adopted by the present invention is: a method for preparing fluorine-containing silicone rubber, comprising: preparing the fluorine-containing monomer described in the first technical solution through direct copolymerization or grafting.

[0020] Preferably, the direct copolymerization method comprises:

[0021] Octamethylcyclotetrasiloxane, octaphenylcyclotetrasiloxane, hexaethylcyclotrisiloxane, tetramethyltetravinylcyclotetrasiloxane and a capping agent are used as raw materials, a catalyst is added, nitrogen is purged, and after heating, one of the fluorine-containing monomers containing -Si(OEt)2-, -Si(OMe)2-, and -Si(OH)2- is added; the temperature is increased to carry out a polymerization reaction; after the polymerization is completed, acetic acid and citric acid are added and stirred overnight, the polymer is collected and dried to obtain a fluorine-containing silicone rubber.

[0022] Preferably, the grafting method comprises:

[0023] Octamethylcyclotetrasiloxane, octaphenylcyclotetrasiloxane, hexaethylcyclotrisiloxane, tetramethyltetravinylcyclotetrasiloxane and a capping agent are used as raw materials, a catalyst is added; a Pt catalyst is added, The fluorine-containing monomers are kneaded at room temperature to obtain fluorine-containing silicone rubber;

[0024] Or octamethylcyclotetrasiloxane, octaphenylcyclotetrasiloxane, hexaethylcyclotrisiloxane, hydrogen-containing silicone oil, tetramethyltetravinylcyclotetrasiloxane, and a capping agent are used as raw materials, a catalyst is added, and a hydrogen-containing polysiloxane is synthesized; a Pt catalyst, the fluorine-containing monomer containing a carbon-carbon double bond, and the fluorine-containing monomer containing a carbon-carbon double bond are added to the hydrogen-containing polysiloxane. The fluorine-containing monomers with bonds are mixed at room temperature to obtain fluorine-containing silicone rubber.

[0025] Preferably, the end-capping agent is decamethyltetrasiloxane;

[0026] The chemical formula of the catalyst is:

[0027]

[0028] Among them, M1, M2, and M3 are saturated alkanes, including one of CH3CH2-, CH3CH2CH2-, (CH3)2CH-, and (CH3)3C-; M4 is a saturated alkane, including one of CH3-, CH3CH2-, and CH3CH2CH2-.

[0029] The fourth technical solution adopted by the present invention is: a fluorine-containing silicone rubber prepared by the preparation method described in the third technical solution.

[0030] Beneficial effects of the above technical solution:

[0031] (1) A fluorine-containing monomer disclosed in the present invention can be introduced into the structure of ethyl silicone rubber, thereby improving the aging resistance and mechanical properties of the rubber; that is, the fluorine-containing monomer can be used to prepare low-temperature silicone rubber, which is beneficial to improving the heat-oxidative aging resistance and mechanical properties of ethyl silicone rubber.

[0032] (2) The excellent low-temperature resistance of ethyl silicone rubber depends on the ethyl content in the molecular structure. However, the increase in the ethyl content leads to the deterioration of the material's resistance to thermal oxidation aging and mechanical properties. The introduction of fluorine monomers into the polymer can effectively improve the performance. The present invention synthesizes a series of new fluorine-containing monomers, introduces them into the polysiloxane structure through copolymerization and grafting, and prepares fluorine-containing silicone rubbers with different structures. The present invention provides beneficial effects and reliable solutions for the preparation of fluorine-containing monomers and fluorine-containing polysiloxanes, especially for the synthesis of fluorine-containing ethyl silicone rubber, which has a significant effect on improving its thermal oxidation aging and poor mechanical properties. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 A nuclear magnetic resonance comparison diagram of ethyl silicone rubber and ethyl fluorosilicone rubber provided in one embodiment of the present invention;

[0034] Figure 2 A DSC comparison chart of ethyl silicone rubber and ethyl fluorosilicone rubber provided in one embodiment of the present invention;

[0035] Figure 3 This is a thermogravimetric comparison diagram of ethyl silicone rubber and ethyl fluorosilicone rubber provided in one embodiment of the present invention. DETAILED DESCRIPTION

[0036] The present invention is further described below through specific embodiments. It should be pointed out that, for ordinary technicians in this field, several modifications and improvements can be made without departing from the principle of the present invention, and these should also be regarded as belonging to the protection scope of the present invention.

[0037] The contents not described in detail in the specification of the present invention belong to the common knowledge of the professionals in this field.

[0038] The present invention discloses a fluorine-containing monomer, the structure of which contains Key or Preferred Key or Specifically, the fluorine-containing monomer is at least one monomer of the following compounds:

[0039]

[0040]

[0041] Among them, R1 and R2 are H or substituents with less than 8 carbon atoms, such as methyl, ethyl, propyl, isopropyl, phenyl, etc., and may be the same or different; R is a structure containing F and C obtained by fluorination of R3, that is, R is CH3-CH(F)-CH2-, CH3-CH(F)CH2CH2-, Ph-CH2-CH(F)-CH3, etc., and R3 is a substituent containing a carbon-carbon double bond (carbon number ≤ 10), such as CH2=CH-CH2-, CH2=CHCH2CH2-, Ph-CH2-CH=CH2, etc.

[0042] R4 is a substituent containing -Si(OEt)2-, a substituent having a straight chain or branched structure (with a carbon number ≤ 12) containing a carbon-carbon double bond, or a terminal substituent containing substituent; the substituent containing -Si(OEt)2- is, for example, R1Si(OEt)2-, including PhSi(OEt)2-, MeSi(OEt)2-, EtSi(OEt)2-, PrSi(OEt)2-, etc.; the substituent containing a carbon-carbon double bond and having a straight chain or branched structure (carbon number ≤ 12) is, for example, CH2=CHCH2-, CH2=CHCH(CH3)-, CH2=CHCH2CH2-, CH2=CHC(CH3) 2- , CH2=CHCH2CH2CH2-, CH2=CHCH2CH2CH2CH2-, CH2=C(CH3)CH2CH2-, CH2=C(CH2CH3)CH2CH2-, CH2=CHCH(Ph)-, etc.; the terminal contains The substituents are, for example, R1R2SiH-, R1SiH2- or R1SiHCl-, where R1 and R2 are H or substituents having less than 8 carbon atoms, such as methyl, ethyl, propyl, isopropyl, phenyl, etc., and may be the same or different.

[0043] R5 has the same structure as R4, that is, R5 is a substituent containing -Si(OEt)2-, a substituent containing a carbon-carbon double bond and having a straight chain or branched structure (the number of carbon atoms is ≤ 12), or a substituent containing a terminal substituent; the substituent containing -Si(OEt)2- is, for example, R1Si(OEt)2-, including PhSi(OEt)2-, MeSi(OEt)2-, EtSi(OEt)2-, PrSi(OEt)2-, etc.; the substituent containing a carbon-carbon double bond and having a straight chain or branched structure (carbon number ≤ 12) is, for example, CH2=CHCH2-, CH2=CHCH(CH3)-, CH2=CHCH2CH2-, CH2=CHC(CH3) 2-, CH2=CHCH2CH2CH2-, CH2=CHCH2CH2CH2CH2-, CH2=C(CH3)CH2CH2-, CH2=C(CH2CH3)CH2CH2-, CH2=CHCH(Ph)-, etc.; the terminal contains The substituents are, for example, R1R2SiH-, R1SiH2- or R1SiHCl-, where R1 and R2 are H or substituents having less than 8 carbon atoms, such as methyl, ethyl, propyl, isopropyl, phenyl, etc., and may be the same or different.

[0044] R6 is a linear alkyl substituent, such as methyl, ethyl, propyl, butyl, etc.; R7 is

[0045]

[0046] The invention discloses a method for preparing a fluorine-containing monomer, comprising synthesizing the fluorine-containing monomer by using silane and a Grignard reagent or an Olah reagent; or synthesizing the fluorine-containing monomer by using a Chen reagent or a FLUOLEAD reagent; or synthesizing the fluorine-containing monomer by an exchange method; wherein the fluorine-containing monomers shown in chemical formulas A1 to A6 and A12 can be synthesized by using silane and a Grignard reagent, and the reaction formula for synthesizing the fluorine-containing monomer by using silane and a Grignard reagent is as follows:

[0047]

[0048] Among them, R1 and R2 are H or a substituent having less than 8 carbon atoms, such as methyl, ethyl, propyl, isopropyl, phenyl, etc., and may be the same or different; R1 and R2 are preferably one of H, methyl, ethyl, propyl, isopropyl, phenyl; more preferably H, methyl, ethyl, propyl, phenyl; R is a structure containing F and C obtained by fluorination of R3, that is, R is CH3-CH(F)-CH2-, CH3-CH(F)CH2CH2-, Ph-CH2-CH(F)-CH3, etc., and R3 is a substituent containing a carbon-carbon double bond (carbon number ≤ 10), such as CH2=CH-CH2-, CH2=CHCH2CH2-, Ph-CH2-CH=CH2, etc.

[0049] The fluorine-containing monomer shown in chemical formula A7 can be synthesized by using Chen's reagent. The reaction formula for synthesizing the fluorine-containing monomer by using Chen's reagent is as follows:

[0050]

[0051] Wherein, R4 is a substituent containing -Si(OEt)2-, a substituent having a straight chain or branched structure (with a carbon number ≤ 12) containing a carbon-carbon double bond, or a terminal substituent containing substituent; the substituent containing -Si(OEt)2- is, for example, R1Si(OEt)2-, including PhSi(OEt)2-, MeSi(OEt)2-, EtSi(OEt)2-, PrSi(OEt)2-, etc.; the substituent containing a carbon-carbon double bond and having a straight chain or branched structure (carbon number ≤ 12) is, for example, CH2=CHCH2-, CH2=CHCH(CH3)-, CH2=CHCH2CH2-, CH2=CHC(CH3) 2- , CH2=CHCH2CH2CH2-, CH2=CHCH2CH2CH2CH2-, CH2=C(CH3)CH2CH2-, CH2=C(CH2CH3)CH2CH2-, CH2=CHCH(Ph)-, etc.; the terminal contains The substituents are, for example, R1R2SiH-, R1SiH2- or R1SiHCl-, R1 and R2 are H or substituents having less than 8 carbon atoms, such as methyl, ethyl, propyl, isopropyl, phenyl, etc., which may be the same or different; X is a halogen;

[0052] That is, R4-X can be a terminal An organic compound with a substituent, X is a halogen, such as R1R2SiHCl or R1SiH2Cl, R1SiHCl2, R1 and R2 are H or a substituent with less than 8 carbon atoms, such as methyl, ethyl, propyl, isopropyl, phenyl, etc., which may be the same or different; R1 and R2 are preferably one of H, methyl, ethyl, propyl, isopropyl, and phenyl;

[0053] R4-X can also be an organic compound containing -Si(OEt)2-substituent, with the structure of R1Si(OEt)2Cl, such as PhSi(OEt)2Cl, MeSi(OEt)2Cl, EtSi(OEt)2Cl, PrSi(OEt)2Cl, etc.; preferably PhSi(OEt)2Cl, MeSi(OEt)2Cl, EtSi(OEt)2Cl;

[0054] R4-X can also be an organic compound (carbon number ≤ 12) with a straight chain or branched structure containing a carbon-carbon double bond, such as CH2=CHCH2Cl, CH2=CHCHClCH3, CH2=CHCH2CH2Cl, CH2=CHCCl(CH3)2, CH2=CHCH2CH2CH2Cl, CH2=CHCH2CH2CH2CH2Cl, CH2=C(CH3)CH2CH2Cl, CH2=C(CH2CH3)CH2CH2Cl, CH2=CHCHCl(Ph), etc.; preferably CH2=CHCH2Cl, CH2=CHCHClCH3, CH2=CHCH2CH2Cl, CH2=CHCCl(CH3)2, CH2=CHCH2CH2CH2CH2Cl, CH2=C(CH3)CH2CH2Cl, CH2=CHCHCl(Ph), etc.

[0055] The fluorine-containing monomer shown in chemical formula A8 can be synthesized using the FLUOLEAD reagent. The reaction formula for synthesizing the fluorine-containing monomer using the FLUOLEAD reagent is as follows:

[0056]

[0057] Wherein, R5 is a substituent containing -Si(OEt)2-, a substituent containing a carbon-carbon double bond and having a straight chain or branched structure (the number of carbon atoms is ≤ 12), or a terminal substituent containing substituent; the substituent containing -Si(OEt)2- is, for example, R1Si(OEt)2-, including PhSi(OEt)2-, MeSi(OEt)2-, EtSi(OEt)2-, PrSi(OEt)2-, etc.; the substituent containing a carbon-carbon double bond and having a straight chain or branched structure (carbon number ≤ 12) is, for example, CH2=CHCH2-, CH2=CHCH(CH3)-, CH2=CHCH2CH2-, CH2=CHC(CH3) 2- , CH2=CHCH2CH2CH2-, CH2=CHCH2CH2CH2CH2-, CH2=C(CH3)CH2CH2-, CH2=C(CH2CH3)CH2CH2-, CH2=CHCH(Ph)-, etc.; the terminal contains The substituents are, for example, R1R2SiH-, R1SiH2- or R1SiHCl-, R1 and R2 are H or substituents having less than 8 carbon atoms, such as methyl, ethyl, propyl, isopropyl, phenyl, etc., which may be the same or different;

[0058] That is, R5-OH can be a terminal An organic compound having a substituent, such as R1R2SiHOH or R1SiH2OH, R1SiHOH2, R1 and R2 are H or a substituent having less than 8 carbon atoms, such as methyl, ethyl, propyl, isopropyl, phenyl, etc., and may be the same or different; R1 and R2 are preferably one of H, methyl, ethyl, propyl, isopropyl, and phenyl; more preferably H, methyl, ethyl, propyl, and phenyl;

[0059] R5-OH can also be an organic compound containing -Si(OEt)2-substituent, with the structure of R1Si(OEt)2OH, such as PhSi(OEt)2OH, MeSi(OEt)2OH, EtSi(OEt)2OH, PrSi(OEt)2OH, etc.; preferably PhSi(OEt)2OH, MeSi(OEt)2OH, EtSi(OEt)2OH;

[0060] R5-OH can also be an organic compound (carbon number ≤ 12) with a straight chain or branched structure containing a carbon-carbon double bond, such as

[0061] CH2=CHCH2CH2OH, CH2=CHCH2CH2CH2OH, CH2=CHCH2CH2CH2CH2OH,

[0062] CH2=C(CH3)CH2CH2OH, CH2=C(CH2CH3)CH2CH2OH,

[0063] CH2=C(CH2CH3)CH2CH2CH2CH2OH, CH2=CHCH2CHOH(CH3),

[0064] CH2=CHCH2CH2CHOH(CH2CH3), CH2=CHCH2CHOH(CH2CH3), CH2=C(Ph)CH2CH2OH

[0065] etc.; preferably CH2=CHCH2CH2CH2OH, CH2=CHCH2CH2CH2CH2OH, CH2=C(CH3)CH2CH2OH, CH2=C(CH2CH3)CH2CH2OH, CH2=C(CH2CH3)CH2CH2CH2OH, CH2=CHCH2CHOH(CH3), CH2=CHCH2CH2CHOH(CH2CH3), CH2=CHCH2CHOH(CH2CH3), CH2=C(Ph)CH2CH2OH; more preferably CH2=CHCH2CH2CH2OH, CH2=CHCH2CH2CH2OH, CH2=CHCH2CH2CH2CH2OH, CH2=C(CH3)CH2CH2OH, CH2=C(CH2CH3)CH2CH2OH, CH2=C(CH2CH3)CH2CH2CH2OH, CH2=C(CHCH2CH2CHOH(CH3), CH2=C(Ph)CH2CH2OH.

[0066] The fluorine-containing monomer shown in Chemical Formula A9 can be synthesized by the exchange method. The reaction formula for synthesizing the fluorine-containing monomer by the exchange method is as follows:

[0067]

[0068] Wherein, R6 is a linear alkyl substituent, such as methyl, ethyl, propyl, butyl, etc., preferably methyl, ethyl and propyl; R7 is

[0069] The present invention discloses a method for preparing fluorine-containing silicone rubber, wherein the fluorine-containing silicone rubber is prepared by direct copolymerization and grafting based on the fluorine-containing monomer as described in the first technical solution; wherein the fluorine-containing group in the fluorine-containing silicone rubber is in the side chain and connected to the main chain of the fluorine-containing silicone rubber through a Si-C bond or a Si-O bond;

[0070] Direct copolymerization methods include:

[0071] Octamethylcyclotetrasiloxane, octaphenylcyclotetrasiloxane, hexaethylcyclotrisiloxane, tetramethyltetravinylcyclotetrasiloxane and a capping agent (for example, decamethyltetrasiloxane) are used as main raw materials, the molar ratio of methyl:phenyl:ethyl segments is regulated to be (10-95):(0-25):(0-45), the ratio of different segments is preferably (10-90):(0-20):(0-35), more preferably (15-85):(0-15):(0-30); the vinyl content is 0.2-1.5%, preferably 0.3-1.3%, more preferably 0.5-1.2%; a catalyst is added, nitrogen is purged for 1 hour, the temperature is raised to 80-120° C. and maintained for 0.5-1 hour, preferably maintained at 85-115° C. for 35-40 minutes; 55min, more preferably keep it at 90-110℃ for 40-50min; add one of the fluorine-containing monomers containing -Si(OEt)2-, -Si(OMe)2-, -Si(OH)2- in the first technical scheme, and adjust the molar amount of the fluorine-containing monomer to 1-30% of the total amount of (methyl + phenyl + ethyl), preferably the molar amount is 5-28%, more preferably 8-25%; increase the reaction temperature to 120-170℃, continue the reaction for 1-6h, preferably increase the temperature to 125-165℃ for 1.5-5h, more preferably increase the temperature to 130-160℃ for 2-4h; after the polymerization is completed, add acetic acid and citric acid and stir overnight, collect the polymer and dry it in a vacuum oven at 100℃ for 12h to obtain fluorine-containing silicone rubber.

[0072] Grafting methods include:

[0073] Octamethylcyclotetrasiloxane, octaphenylcyclotetrasiloxane, hexaethylcyclotrisiloxane, tetramethyltetravinylcyclotetrasiloxane and a capping agent (for example, decamethyltetrasiloxane) are used as main raw materials, the molar ratio of methyl:phenyl:ethyl:vinyl chain segments is regulated to be (10-95):(0-25):(0-45):(3-35), and the molar ratio of different chain segments is preferably (10-90):(0-20):(0-35):(3-30), and more preferably (15-85):(0-15):(0-30)::(5-25); a catalyst is added to synthesize high vinyl siloxane, and the siloxane containing the first technical solution is added during mixing. Fluorine monomers to regulate the vinyl and The molar ratio is 0.9-1.05, preferably 0.92-1.04, and more preferably 0.94-1.03; Pt catalyst is added at the same time, kneading is carried out at room temperature for 3-30 minutes, and then kept at 35-50°C for 0.5-8 hours, preferably kneading at room temperature for 5-25 minutes, and kept at 38-45°C for 1-7 hours, more preferably mixing at room temperature for 6-20 minutes, and kept at 40-45°C for 1.5-6 hours; a fluorine-containing silicone polymer, i.e., fluorine-containing silicone rubber, is obtained.

[0074] Or octamethylcyclotetrasiloxane, octaphenylcyclotetrasiloxane, hexaethylcyclotrisiloxane, hydrogen-containing silicone oil, tetramethyltetravinylcyclotetrasiloxane, and an end-capping agent (for example, decamethyltetrasiloxane) are used as main raw materials, the molar ratio of methyl:phenyl:ethyl segments is adjusted to be (10-100):(0-25):(0-45), and the molar ratio of different segments is preferably (10-90):(0-20):(0-35), and more preferably (15-85):(0-15):(0-30); a catalyst is added to synthesize hydrogen-containing polysiloxane (hydrogen content 1-35%), and the amount of hydrogen-containing polysiloxane added is preferably 3-30%, and more preferably 5-25%; during mixing, the fluorine-containing monomer containing carbon-carbon double bonds and the fluorine-containing monomer containing carbon-carbon double bonds in the first technical solution are added; fluorinated monomers with carbon-carbon double bonds and The molar ratio of the bonds is 0.9 to 1.05, preferably 0.92 to 1.04, and more preferably 0.94 to 1.03; a Pt catalyst is added at the same time, and the mixture is kneaded at room temperature for 3 to 30 minutes, and then kept at 35 to 50°C for 0.5 to 8 hours, preferably kneaded at room temperature for 5 to 25 minutes, and kept at 38 to 45°C for 1 to 7 hours, and more preferably kneaded at room temperature for 6 to 20 minutes, and kept at 40 to 45°C for 1.5 to 6 hours; a fluorine-containing silicone polymer, i.e., a fluorine-containing silicone rubber, is obtained.

[0075] Among them, the chemical formula of the catalyst used in the direct copolymerization method and the grafting method is:

[0076]

[0077] Among them, M1, M2, and M3 are saturated alkanes, including one of CH3CH2-, CH3CH2CH2-, (CH3)2CH-, (CH3)3C-, etc., preferably CH3CH2-, (CH3)2CH-, (CH3)3C-, that is, M1, M2, and M3 are, for example, triethylamine, tributylamine, N,N-dimethylbutylamine, decylamine, dodecanamine, etc.; M4 is a saturated alkane, including one of CH3-, CH3CH2-, CH3CH2CH2-, etc., preferably CH3CH2-, CH3CH2CH2-, that is, M4-OH is, for example, one of methanol, ethanol, propanol, isopropanol, etc.

[0078] The preparation process of the catalyst is:

[0079]

[0080] Among them, H—X1 is hydrogen chloride gas and can also be methyl bromide, hydrogen bromide and other gases.

[0081] Example 1

[0082] (1) Preparation of fluorinated monomers;

[0083] A 500 ml dry three-necked flask was filled with high-purity nitrogen, replaced three times, and 200 ml of ether and (EtO)3SiHCl were added in sequence. In an ice bath, the Grignard reagent CH2=CHCH3CH2MgBr (1:1) was slowly added, and the temperature was gradually raised to 40°C for reaction for 12 h. The reaction was terminated, and the mixture was filtered, extracted, and dried in sequence to obtain CH2=CCH3CH2(EtO)2SiH; the mixture was transferred to a 500 ml round-bottom flask filled with high-purity nitrogen, 50 ml of ether was added, and Olah reagent (HF / Py) was slowly added. The mixture was reacted at 15°C for 12 h. The reaction was terminated, and the mixture was filtered, extracted, and dried in sequence to obtain CH3CFCH3CH2(EtO)2SiH.

[0084] (2) Catalyst preparation;

[0085] 18 mmol of trioctylamine was weighed and uniformly mixed in 180 ml of ethanol solution, methyl bromide gas was introduced to control the pressure to 0.3 MPa, and after reacting for 3 hours, a catalyst intermediate was obtained, which was filtered, refined, washed, concentrated, and crystallized in sequence, 2 g was weighed and dissolved in 100 ml of ethanol solution, 2 g of NaOH was added to react, and after the reaction, the catalyst was obtained by filtering several times; then 0.8 g of the catalyst and 40 g of octamethylcyclotetrasiloxane solution were placed in a 100 ml round-bottom flask, nitrogen was filled and replaced three times, and the temperature was raised to a certain temperature to react for 7 hours to obtain an alkali gel containing the catalyst, which was placed in a desiccator in a nitrogen atmosphere for storage.

[0086] (3) Preparation of fluorinated polyorganosiloxane, i.e., preparation of fluorinated silicone rubber;

[0087] In a 1L glass reactor, octamethylcyclotetrasiloxane, octaphenylcyclotetrasiloxane, hexaethylcyclotrisiloxane, tetramethyltetravinylcyclotetrasiloxane, and a capping agent (for example, decamethyltetrasiloxane) are added as main raw materials in sequence, and a catalyst is added, wherein the molar ratio of methyl:phenyl:ethyl segments is 73:2:25, and the vinyl content is 0.8%. Nitrogen is purged for 1 hour, the temperature is raised to 80 and maintained for 40 minutes, CH3CFCH3CH2(EtO)2SiH is added, and the molar amount of the fluorine monomer is regulated to be 5% of (methyl+phenyl+ethyl). The reaction temperature is raised to 135°C, and the reaction is continued for 5 hours. After the polymerization is completed, acetic acid and citric acid are added and stirred overnight, and the polymer is collected and dried in a vacuum oven at 100°C for 12 hours to obtain the product. Its glass transition temperature is -129°C, and after hot air aging at 150°C×72h, the mechanical properties decrease by 5%.

[0088] Example 2

[0089] (1) Preparation of fluorinated monomers

[0090] A 500 ml dry three-necked flask was filled with high-purity nitrogen, replaced three times, and 200 ml of ether and Et(Me)SiHCl were added in sequence. In an ice bath, Grignard reagent CH2=CHCH3CH2MgBr (1:1.2) was slowly added, and the temperature was gradually raised to 40°C for reaction for 12 h. The reaction was terminated, and the mixture was filtered, extracted, and dried in sequence to obtain CH2=CCH3CH2Et(Me)SiH; the mixture was transferred to a 500 ml round-bottom flask filled with high-purity nitrogen, 50 ml of ether was added, and Olah reagent (HF / Py) was slowly added. The mixture was reacted at 15°C for 12 h. The reaction was terminated, and the mixture was filtered, extracted, and dried in sequence to obtain CH3CFCH3CH2Et(Me)SiH.

[0091] (2) Catalyst preparation

[0092] 18 mmol of trioctylamine was weighed and uniformly mixed in 180 ml of ethanol solution, methyl bromide gas was introduced to control the pressure to 0.3 MPa, and after reacting for 3 hours, a catalyst intermediate was obtained, which was filtered, refined, washed, concentrated, and crystallized in sequence, 2 g was weighed and dissolved in 100 ml of ethanol solution, 2 g of NaOH was added to react, and after the reaction, the catalyst was obtained by filtering several times. Then 0.8 g of the catalyst and 40 g of octamethylcyclotetrasiloxane solution were placed in a 100 ml round-bottom flask, nitrogen was filled and replaced three times, and the temperature was raised to a certain temperature and reacted for 7 hours to obtain a catalyst-containing alkali glue, which was placed in a desiccator in a nitrogen atmosphere and stored for later use.

[0093] (3) Preparation of fluorinated silicone rubber

[0094] In a 1L glass reactor, octamethylcyclotetrasiloxane, octaphenylcyclotetrasiloxane, hexaethylcyclotrisiloxane, tetramethyltetravinylcyclotetrasiloxane, and a capping agent (for example, decamethyltetrasiloxane) are added as main raw materials in sequence, and a catalyst is added, wherein the molar ratio of methyl:phenyl:ethyl:vinyl chain segments is 65:2:25:8, nitrogen is purged for 1 hour, and the temperature is raised to 120°C and maintained for 5 hours; the obtained polymer is processed on an open mill, CH3CFCH3CH2Et(Me)SiH is added, the molar ratio of vinyl chain segments to ≡SiH-containing fluorine monomer is adjusted to 0.98, a Pt catalyst is added, and mixing is carried out at room temperature for 12 minutes, and then maintained at 45°C for 5 hours to obtain a fluorine-containing silicone polymer. Its glass transition temperature is -128°C, and after hot air aging at 150°C×72h, the mechanical properties decrease by 8%.

[0095] Example 3

[0096] (1) Preparation of fluorinated monomers

[0097] A 500ml dry three-necked flask was filled with high-purity nitrogen and replaced three times. 200ml of ether and PhSi(OEt)2Cl were added in sequence. The aged reagent FO2SCF2COOMe (1:1) was slowly added in an ice bath. The temperature was gradually raised to 40°C for reaction for 12h. The reaction was terminated and the reaction was filtered, extracted and dried to obtain PhSi(OEt)2CF3. The fluorinated monomer was obtained by filtering, extracting and drying.

[0098] (2) Catalyst preparation

[0099] 18 mmol of tributylamine was weighed and uniformly mixed in 180 ml of ethanol solution, methyl bromide gas was introduced to control the pressure to 0.3 MPa, and after reacting for 3 hours, a catalyst intermediate was obtained, which was filtered, refined, washed, concentrated, and crystallized in sequence, 2 g was weighed and dissolved in 100 ml of ethanol solution, 2 g of NaOH was added to react, and after the reaction, the catalyst was obtained by filtering several times. Then 0.8 g of the catalyst and 40 g of octamethylcyclotetrasiloxane solution were placed in a 100 ml round-bottom flask, nitrogen was filled and replaced three times, and the temperature was raised to a certain temperature and reacted for 7 hours to obtain a catalyst-containing alkali glue, which was placed in a desiccator in a nitrogen atmosphere and stored for standby use.

[0100] (3) Preparation of fluorinated silicone rubber

[0101] In a 1L glass reactor, octamethylcyclotetrasiloxane, octaphenylcyclotetrasiloxane, hexaethylcyclotrisiloxane, tetramethyltetravinylcyclotetrasiloxane, and a capping agent (for example, decamethyltetrasiloxane) are added as main raw materials in sequence, and a catalyst is added, wherein the molar ratio of methyl:phenyl:ethyl segments is 78:2:20, and the vinyl content is 0.8%. Nitrogen is purged for 1 hour, the temperature is raised to 80 and maintained for 40 minutes, PhSi(OEt)2CF3 is added, and the molar amount of the fluorine monomer is regulated to be 10% of (methyl+phenyl+ethyl). The reaction temperature is raised to 135°C, and the reaction is continued for 5 hours. After the polymerization is completed, acetic acid and citric acid are added and stirred overnight, and the polymer is collected and dried in a vacuum oven at 100°C for 12 hours to obtain the product. Its glass transition temperature is -126°C, and after hot air aging at 150°C×72h, the mechanical properties decrease by 2%.

[0102] Example 4

[0103] (1) Preparation of fluorinated monomers

[0104] A 500 ml dry three-necked flask was filled with high-purity nitrogen, replaced three times, and 200 ml of ether and EtSiH2Cl were added in sequence. In an ice bath, the Grignard reagent Ph-CH-CH=CH2MgBr (1:1.2) was slowly added, and the temperature was gradually raised to 40°C for reaction for 12 hours. The reaction was terminated, and the reaction was filtered, extracted, and dried in sequence to obtain Ph-CH-CH=CH(Et)SiH2; the mixture was transferred to a 500 ml round-bottom flask filled with high-purity nitrogen, 50 ml of ether was added, and Olah reagent (HF / Py) was slowly added. The reaction was carried out at 15°C for 12 hours. The reaction was terminated, and the reaction was filtered, extracted, and dried in sequence to obtain Ph-CH-CH(F)-CH2(Et)SiH2.

[0105] (2) Catalyst preparation

[0106] 18 mmol of trioctylamine was weighed and uniformly mixed in 180 ml of ethanol solution, methyl bromide gas was introduced to control the pressure to 0.3 MPa, and after reacting for 3 hours, a catalyst intermediate was obtained, which was filtered, refined, washed, concentrated, and crystallized in sequence, 2 g was weighed and dissolved in 100 ml of ethanol solution, 2 g of NaOH was added to react, and after the reaction, the catalyst was obtained by filtering several times. Then 0.8 g of the catalyst and 40 g of octamethylcyclotetrasiloxane solution were placed in a 100 ml round-bottom flask, nitrogen was filled and replaced three times, and the temperature was raised to a certain temperature and reacted for 7 hours to obtain a catalyst-containing alkali glue, which was placed in a desiccator in a nitrogen atmosphere and stored for later use.

[0107] (3) Preparation of fluorinated silicone rubber

[0108] In a 1L glass reactor, octamethylcyclotetrasiloxane, octaphenylcyclotetrasiloxane, hexaethylcyclotrisiloxane, tetramethyltetravinylcyclotetrasiloxane, and a capping agent (for example, decamethyltetrasiloxane) are added in sequence as main raw materials, and a catalyst is added, wherein the molar ratio of methyl:phenyl:ethyl:vinyl segments is 58:2:25:15, nitrogen is purged for 1 hour, and the temperature is raised to 120°C and maintained for 5 hours; the obtained polymer is processed on an open mill, and Ph-CH-CH(F)-CH2(Et)SiH2 is added to regulate the vinyl segments and the content of The molar ratio of the fluorinated monomer is 0.98, a Pt catalyst is added, the mixture is mixed at room temperature for 12 minutes, and then kept at 45°C for 5 hours to obtain a fluorinated silicone polymer. Its glass transition temperature is -125°C, and after hot air aging at 150°C for 72 hours, the mechanical properties decrease by 3%.

[0109] Example 5

[0110] (1) Preparation of fluorinated monomers

[0111] A 500ml dry three-necked flask was filled with high-purity nitrogen and replaced three times. 200ml of ether and CH2=CHCH2CH2CH2OH were added in sequence. FLUOLEAD reagent (1:1) was slowly added in an ice bath. The temperature was gradually raised to 40°C and the reaction was carried out for 12h. The reaction was terminated, and the fluorinated monomer CH2=CHCH2CH2CH2F was obtained by filtering, extracting and drying in sequence.

[0112] (2) Catalyst preparation

[0113] 18 mmol of tributylamine was weighed and uniformly mixed in 180 ml of ethanol solution, methyl bromide gas was introduced to control the pressure to 0.3 MPa, and after reacting for 3 hours, a catalyst intermediate was obtained, which was filtered, refined, washed, concentrated, and crystallized in sequence, 2 g was weighed and dissolved in 100 ml of ethanol solution, 2 g of NaOH was added to react, and after the reaction, the catalyst was obtained by filtering several times. Then 0.8 g of the catalyst and 40 g of octamethylcyclotetrasiloxane solution were placed in a 100 ml round-bottom flask, nitrogen was filled and replaced three times, and the temperature was raised to a certain temperature and reacted for 7 hours to obtain a catalyst-containing alkali glue, which was placed in a desiccator in a nitrogen atmosphere and stored for standby use.

[0114] (3) Preparation of fluorinated silicone rubber

[0115] In a 1L glass reactor, octamethylcyclotetrasiloxane, octaphenylcyclotetrasiloxane, hexaethylcyclotrisiloxane, tetramethyltetravinylcyclotetrasiloxane, and a capping agent (for example, decamethyltetrasiloxane) are added in sequence as main raw materials, wherein the molar ratio of methyl:phenyl:ethyl segments is 78:2:20, and the vinyl content is 0.8%. A catalyst is added, and hydrogen-containing silicone oil is added at the same time to adjust the hydrogen content to 12%. Nitrogen is purged for 1 hour, and the temperature is raised to 125°C for reaction for 2 hours. The obtained polymer is processed on an open mill, and CH2=CHCH2CH2CH2F is added to adjust the vinyl segments and The molar ratio of fluorine to silicon was 0.98, Pt catalyst was added, kneaded at room temperature for 12 minutes, and then kept at 50°C for 5 hours to obtain a fluorine-containing silicone polymer. Its glass transition temperature was -125°C, and after hot air aging at 150°C for 72 hours, the mechanical properties decreased by 6%.

[0116] Example 6

[0117] (1) Preparation of fluorinated monomers

[0118] A 500 ml dry three-necked flask was filled with high-purity nitrogen and replaced three times. 200 ml of ether and Et2SiHOH were added in sequence. Grignard reagent FLUOLEAD reagent (1:1.2) was slowly added in an ice bath. The temperature was gradually raised to 40°C for reaction for 12 hours. The reaction was terminated, and Et2SiHF was obtained by filtering, extracting and drying in sequence.

[0119] (2) Catalyst preparation

[0120] 18 mmol of trioctylamine was weighed and uniformly mixed in 180 ml of ethanol solution, methyl bromide gas was introduced to control the pressure to 0.3 MPa, and after reacting for 3 hours, a catalyst intermediate was obtained, which was filtered, refined, washed, concentrated, and crystallized in sequence, 2 g was weighed and dissolved in 100 ml of ethanol solution, 2 g of NaOH was added to react, and after the reaction, the catalyst was obtained by filtering several times. Then 0.8 g of the catalyst and 40 g of octamethylcyclotetrasiloxane solution were placed in a 100 ml round-bottom flask, nitrogen was filled and replaced three times, and the temperature was raised to a certain temperature and reacted for 7 hours to obtain a catalyst-containing alkali glue, which was placed in a desiccator in a nitrogen atmosphere and stored for later use.

[0121] (3) Preparation of fluorinated silicone rubber

[0122] In a 1L glass reactor, octamethylcyclotetrasiloxane, octaphenylcyclotetrasiloxane, hexaethylcyclotrisiloxane, tetramethyltetravinylcyclotetrasiloxane, and a capping agent (for example, decamethyltetrasiloxane) are added in sequence as main raw materials, and a catalyst is added, wherein the molar ratio of methyl:phenyl:ethyl:vinyl segments is 58:2:30:10, nitrogen is purged for 1 hour, and the temperature is raised to 120°C and maintained for 5 hours; the obtained polymer is processed on an open mill, and Et2SiHF is added to regulate the vinyl segments and the content of The molar ratio of the fluorine monomer is 0.99, a Pt catalyst is added, the mixture is mixed at room temperature for 30 minutes, and then kept at 45°C for 5 hours to obtain a fluorine-containing silicone polymer. Its glass transition temperature is -125°C, and after hot air aging at 150°C for 72 hours, the mechanical properties decrease by 5%.

[0123] Example 7

[0124] (1) Preparation of fluorinated monomers

[0125] A 500 ml dry three-necked flask was filled with high-purity nitrogen and replaced three times. 200 ml of tetrahydrofuran, trifluoroethanol and EtSi(OH)3 were added in sequence. Acid catalyst was added to react for 5 hours. EtSi(OCH2CF3)(OH)2 was obtained after purification and separation.

[0126] (2) Catalyst preparation

[0127] 18 mmol of tributylamine was weighed and uniformly mixed in 180 ml of ethanol solution, methyl bromide gas was introduced to control the pressure to 0.3 MPa, and after reacting for 3 hours, a catalyst intermediate was obtained, which was filtered, refined, washed, concentrated, and crystallized in sequence, 2 g was weighed and dissolved in 100 ml of ethanol solution, 2 g of NaOH was added to react, and after the reaction, the catalyst was obtained by filtering several times. Then 0.8 g of the catalyst and 40 g of octamethylcyclotetrasiloxane solution were placed in a 100 ml round-bottom flask, nitrogen was filled and replaced three times, and the temperature was raised to a certain temperature and reacted for 7 hours to obtain a catalyst-containing alkali glue, which was placed in a desiccator in a nitrogen atmosphere and stored for standby use.

[0128] (3) Preparation of fluorinated silicone rubber

[0129] In a 1L glass reactor, octamethylcyclotetrasiloxane, octaphenylcyclotetrasiloxane, hexaethylcyclotrisiloxane, tetramethyltetravinylcyclotetrasiloxane, and a capping agent (for example, decamethyltetrasiloxane) are added as main raw materials in sequence, and a catalyst is added, wherein the molar ratio of methyl:phenyl:ethyl segments is 75:5:20, and the vinyl content is 0.8%. Nitrogen is purged for 1 hour, the temperature is raised to 80 and maintained for 40 minutes, EtSi(OCH2CF3)(OH)2 is added, and the molar amount of the fluorine monomer is regulated to be 18% of (methyl+phenyl+ethyl), the reaction temperature is raised to 135°C, and the reaction is continued for 5 hours. After the polymerization is completed, acetic acid and citric acid are added and stirred overnight, and the polymer is collected and dried in a vacuum oven at 100°C for 12 hours to obtain the product. Its glass transition temperature is -121°C, and after hot air aging at 150°C×72h, the mechanical properties decrease by 4%.

[0130] Comparative Example 1

[0131] Comparative Example 1 corresponding to Example 1 is set, and the specific preparation process is as follows: in a 1L glass reactor, octamethylcyclotetrasiloxane, octaphenylcyclotetrasiloxane, hexaethylcyclotrisiloxane, tetramethyltetravinylcyclotetrasiloxane, and end-capping agent (for example, decamethyltetrasiloxane) are added in sequence as main raw materials, wherein the molar ratio of methyl:phenyl:ethyl chain segment is 73:2:25, and the vinyl content is 0.8%. Nitrogen is purged for 1 hour, the temperature is raised to 80 and maintained for 40 minutes, the reaction temperature is raised to 135°C, and the reaction is continued for 5 hours. After the polymerization is completed, acetic acid and citric acid are added and stirred overnight, and the polymer is collected and dried in a vacuum oven at 100°C for 12 hours to obtain a product. Its glass transition temperature is -130°C, and after hot air aging at 150°C×72h, the mechanical properties decrease by 23%.

[0132] Comparative Example 2

[0133] Comparative Example 2 corresponding to Example 2 is set up, and the specific preparation process is as follows: in a 1L glass reactor, octamethylcyclotetrasiloxane, octaphenylcyclotetrasiloxane, hexaethylcyclotrisiloxane, tetramethyltetravinylcyclotetrasiloxane, and a capping agent (for example, a capping agent is decamethyltetrasiloxane) are added in sequence as main raw materials, and a catalyst is added, wherein the molar ratio of methyl:phenyl:ethyl:vinyl chain segments is 65:2:25:8, nitrogen is purged for 1h, and the temperature is raised to 120°C and maintained for 5h; the obtained polymer is processed on an open mill to obtain an organosilicon polymer. Its glass transition temperature is -129°C, and after hot air aging at 150°C×72h, the mechanical properties decrease by 32%.

[0134] Comparative Example 3

[0135] Comparative Example 3 corresponding to Example 3 is set, and the specific preparation process is as follows: in a 1L glass reactor, octamethylcyclotetrasiloxane, octaphenylcyclotetrasiloxane, hexaethylcyclotrisiloxane, tetramethyltetravinylcyclotetrasiloxane, and end-capping agent (for example, decamethyltetrasiloxane) are added in sequence as main raw materials, and a catalyst is added, wherein the molar ratio of methyl:phenyl:ethyl chain segment is 78:2:20, and the vinyl content is 0.8%. Nitrogen is purged for 1 hour, the temperature is raised to 80 and maintained for 40 minutes, the reaction temperature is raised to 135°C, and the reaction is continued for 5 hours. After the polymerization is completed, acetic acid and citric acid are added and stirred overnight, and the polymer is collected and dried in a vacuum oven at 100°C for 12 hours to obtain a product. Its glass transition temperature is -128°C, and after hot air aging at 150°C×72h, the mechanical properties decrease by 19%.

[0136] Comparative Example 4

[0137] A comparative example 4 corresponding to Example 4 is set up, and the specific preparation process is as follows: in a 1L glass reactor, octamethylcyclotetrasiloxane, octaphenylcyclotetrasiloxane, hexaethylcyclotrisiloxane, tetramethyltetravinylcyclotetrasiloxane, and a capping agent (the capping agent is, for example, decamethyltetrasiloxane) are added in sequence as main raw materials, a catalyst is added, wherein the molar ratio of methyl:phenyl:ethyl:vinyl chain segments is 58:2:25:15, nitrogen is purged for 1 hour, the temperature is raised to 120°C and maintained for 5 hours; mixing at room temperature for 12 minutes, and then maintained at 45°C for 5 hours to obtain a product, whose glass transition temperature is -133°C, and after hot air aging at 150°C×72h, the mechanical properties decrease by 21%.

[0138] The fluorinated silicone rubber (i.e., ethyl fluorosilicone rubber) prepared in Examples 1 to 7 and the ethyl silicone rubber prepared in Comparative Examples 1 to 4 were subjected to NMR, DSC, and thermogravimetric measurements. The obtained measurement data are shown in Table 1. The NMR comparison diagram of ethyl silicone rubber and ethyl fluorosilicone rubber is shown in Figure 1 , the DSC comparison chart of ethyl silicone rubber and ethyl fluorosilicone rubber is shown in Figure 2, the thermogravimetric comparison of ethyl silicone rubber and ethyl fluorosilicone rubber is shown in Figure 3 .

[0139] Table 1 Measurement results

[0140]

[0141]

[0142] Figure 1 It is ethyl silicone rubber and ethyl fluorosilicone rubber 1 HNMR spectrum, the solvent is deuterated chloroform; Figure 1 It can be seen that the chemical shift δ = 0 ~ 0.16 corresponds to SiCH3 * , δ=0.44~0.54 corresponds to SiCH2*CH3, δ=0.9~0.96 corresponds to SiCH2CH3*, δ=5.7~5.8 corresponds to SiCH * =CH2, δ=5.9~6.2 corresponds to SiCH=CH2*; it shows that the synthesized polymer is a polymer containing SiCH3, SiCH2CH3 and Si-CH=CH2, and the ethyl silicone rubber is successfully synthesized; at the same time, δ=5.6-6.2 is the chemical shift of hydrogen on Si-CH=CH2, δ=0.7-0.8 and 2.0-2.1 are the chemical shifts of hydrogen on α and β positions on Si-CH2CH2CF3, respectively, indicating that -CH2CH2CF3 is successfully introduced into ethyl silicone rubber, and ethyl fluorosilicone rubber is successfully synthesized; the actual content can be further verified according to the integral of the NMR image to be consistent with the feed ratio.

[0143] From the data in Table 1, it can be seen that with the increase of ethyl content, the Tg of ethyl silicone rubber gradually decreases. When the ethyl content is 25%, the Tg is close to -130℃, and no crystallization phenomenon occurs. There is no other transition temperature besides this. Figure 2 It is the DSC graph of the embodiment and the comparative example. When the fluorine-containing group is introduced into the ethylphenyl silicone rubber, the glass transition temperature of the obtained ethyl fluorophenyl silicone rubber increases. This is because when the fluorine-containing bulky group is introduced into the main chain or side chain of silicon oxygen, it is randomly distributed with dimethylsiloxane, and the proportion of single bonds that can rotate internally on the main chain is relatively reduced, which destroys the regularity of the general ethyl silicone rubber macromolecule, deteriorates the flexibility of the molecular chain, increases the glass transition temperature, and deteriorates the low temperature resistance.

[0144] like Figure 3 The thermogravimetric analysis of ethylbenzene silicone rubber and ethylfluorobenzene silicone rubber revealed that as the ethyl content increased, the dimethyl chain segments decreased, and the overall trend was that the high temperature resistance deteriorated. 20% ethyl content → T 50wt％ ≈380℃, 25% ethyl content → T 50wt％≈400℃, generally above 370℃; when fluorine groups are introduced into ethylbenzene silicone rubber, its heat resistance is improved. When the ethyl content is the same, the higher the fluorine content, the stronger the high temperature performance; at the same time, the mass residual percentage of ethyl silicone rubber is low, close to 0. This is because in a nitrogen atmosphere, ethyl silicone rubber will undergo main chain unbuttoning degradation, causing the main chain to break and produce volatile cyclic low molecular weight compounds, so its weight loss rate is high and the mass residual percentage is relatively low.

[0145] The fluorinated silicone rubber (i.e., ethyl fluorosilicone rubber) prepared in Examples 1 to 7 and the ethyl silicone rubber prepared in Comparative Examples 1 to 4 were subjected to thermal oxidation aging tests according to standard GB / T 9871 2008 (aging at 150° C. for 72 h and aging at 200° C. for 7 d, respectively), and the tensile strength retention rate and elongation at break retention rate were measured. The test results are shown in Tables 2 and 3.

[0146] Table 2 Thermal oxygen aging performance data after aging at 150℃ for 72h

[0147]

[0148] Table 3 Thermal oxidative aging performance data after aging at 200℃ for 7 days

[0149]

[0150] It can be seen from the data in Table 2 and Table 3 that the introduction of fluorine-containing monomers into ethyl silicone rubber can effectively improve the aging resistance and mechanical properties of ethyl silicone rubber; that is, the present invention introduces fluorine-containing monomers into the structure of ethyl silicone rubber, thereby improving the aging resistance and mechanical properties of the rubber.

[0151] The present invention focuses on synthesizing a variety of fluorine-containing monomers, providing more molecular structures and application ranges for ethyl fluororubber; and verifies the successful synthesis of ethyl silicone rubber, the thermal initial decomposition temperature and glass transition temperature of raw rubber, and the heat-resistant aging and oxidation performance of vulcanized rubber; and, compared with the prior art, the present invention introduces methyl, phenyl, ethyl, fluorine-containing groups, and vinyl groups into silicone rubber, and prepares a series of ethyl silicone rubbers containing a variety of groups in different proportions, and introduces a variety of groups into silicone rubber to increase the steric hindrance of the prepared fluorine-containing silicone rubber, effectively improving the thermal stability of the fluorine-containing silicone rubber, thereby making the fluorine-containing silicone rubber have better aging resistance and mechanical properties; at the same time, the catalyst used in the present invention is a self-made new catalyst, and the new catalyst can effectively reduce the small molecular ring bodies generated in the chain growth stage of anionic ring-opening polymerization, thereby promoting the reaction and improving the yield of the product.

[0152] The present invention is described in detail above in combination with specific implementation methods and exemplary examples. The above description is exemplary, not exhaustive, and is not limited to the disclosed embodiments; the above description cannot be understood as limiting the present invention. Those skilled in the art understand that, without departing from the spirit and scope of the present invention, the technical solution of the present invention and its implementation methods may be subjected to a variety of equivalent substitutions, modifications or improvements, all of which fall within the scope of the present invention; the protection scope of the present invention shall be subject to the attached claims.

Claims

1. A fluorine-containing monomer, characterized in that Includes one of the following compounds: Wherein, R1 and R2 are H or a substituent having less than 8 carbon atoms; R is one of CH3-CH(F)-CH2-, CH3-CH(F)CH2CH2- and Ph-CH2-CH(F)-CH3; R4 and R5 are a substituent containing -Si(OEt)2-, a substituent having a straight chain or branched structure and a carbon-carbon double bond having ≤12 carbon atoms, and a terminal substituent containing One of the substituents of the bond; R6 is a linear alkyl substituent; R7 is 2. The fluorinated monomer according to claim 1, characterized in that The R1 and R2 are one of methyl, ethyl, propyl, isopropyl and phenyl.

3. The fluorinated monomer according to claim 1, characterized in that The substituent containing -Si(OEt)2- is R1Si(OEt)2-; The substituent having a straight chain or branched structure of the carbon-carbon double bond with a carbon number of ≤12 is CH2=CHCH2-, CH2=CHCH(CH3)-, CH2=CHCH2CH2-, CH2=CHC(CH3) 2- 、CH2=CHCH2CH2CH2-、 CH2=CHCH2CH2CH2CH2-, CH2=C(CH3)CH2CH2-, CH2=C(CH2CH3)CH2CH2- and One of CH2=CHCH(Ph)-; The end contains The substituent of the bond is one of R1R2SiH-, R1SiH2- and R1SiHCl-; Wherein, R1 and R2 are one of methyl, ethyl, propyl, isopropyl and phenyl.

4. The fluorinated monomer according to claim 1, characterized in that The R6 is one of methyl, ethyl, propyl and butyl.

5. A method for preparing a fluorine-containing monomer as claimed in any one of claims 1 to 4, characterized in that: include: The fluorine-containing monomers shown in chemical formulas A1 to A6 and A12 are synthesized by using silane and Grignard reagent; the fluorine-containing monomers shown in chemical formula A7 are synthesized by using Chen reagent; the fluorine-containing monomers shown in chemical formula A8 are synthesized by using FLUOLEAD reagent; and the fluorine-containing monomers shown in chemical formula A9 are synthesized by exchange method.

6. A method for preparing fluorine-containing silicone rubber, characterized in that: include: The fluorine-containing monomer according to any one of claims 1 to 4 is prepared by direct copolymerization or grafting.

7. The method for preparing fluorine-containing silicone rubber according to claim 6, characterized in that: The direct copolymerization method comprises: Octamethylcyclotetrasiloxane, octaphenylcyclotetrasiloxane, hexaethylcyclotrisiloxane, tetramethyltetravinylcyclotetrasiloxane and a capping agent are used as raw materials, a catalyst is added, nitrogen is purged, and after heating, one of the fluorine-containing monomers containing -Si(OEt)2-, -Si(OMe)2-, and -Si(OH)2- is added; the temperature is increased to carry out a polymerization reaction; after the polymerization is completed, acetic acid and citric acid are added and stirred overnight, the polymer is collected and dried to obtain a fluorine-containing silicone rubber.

8. The method for preparing fluorine-containing silicone rubber according to claim 6, characterized in that: The grafting method comprises: Octamethylcyclotetrasiloxane, octaphenylcyclotetrasiloxane, hexaethylcyclotrisiloxane, tetramethyltetravinylcyclotetrasiloxane and a capping agent are used as raw materials, a catalyst is added; a Pt catalyst is added, The fluorine-containing monomers are kneaded at room temperature to obtain fluorine-containing silicone rubber; Or octamethylcyclotetrasiloxane, octaphenylcyclotetrasiloxane, hexaethylcyclotrisiloxane, hydrogen-containing silicone oil, tetramethyltetravinylcyclotetrasiloxane, and a capping agent are used as raw materials, a catalyst is added, and a hydrogen-containing polysiloxane is synthesized; a Pt catalyst, the fluorine-containing monomer containing a carbon-carbon double bond, and the fluorine-containing monomer containing a carbon-carbon double bond are added to the hydrogen-containing polysiloxane. The fluorine-containing monomers with bonds are mixed at room temperature to obtain fluorine-containing silicone rubber.

9. The method for preparing fluorine-containing silicone rubber according to any one of claims 7 to 8, characterized in that: The end-capping agent is decamethyltetrasiloxane; The chemical formula of the catalyst is: Among them, M1, M2, and M3 are saturated alkanes, including one of CH3CH2-, CH3CH2CH2-, (CH3)2CH-, and (CH3)3C-; M4 is a saturated alkane, including one of CH3-, CH3CH2-, and CH3CH2CH2-.

10. A fluorine-containing silicone rubber obtained according to the preparation method according to any one of claims 6 to 9.

Images