Fatigue-resistant composite material based on perfluororubber and preparation method of fatigue-resistant composite material

Abstract

The invention discloses a fatigue-resistant composite material based on perfluororubber and a preparation method of the fatigue-resistant composite material, and relates to the technical field of rubber materials, an iron modified cysteine compound is prepared, and iron ions with flame-retardant elements and catalytic action are introduced into a flame-retardant system. The iron ions have catalytic performance, so that the carbonization reaction of the fatigue-resistant composite material of the perfluororubber in the combustion process can be promoted, and the flame retardance is improved. Phytic acid and piperazine are subjected to a salt forming reaction, phytic acid modified piperazine salt is prepared, the phytic acid modified piperazine salt and the iron modified cysteine compound are compounded, and the composite flame retardant is obtained. The composite flame retardant is loaded on aminated polyhedral oligomeric silsesquioxane, the specific surface area of the aminated polyhedral oligomeric silsesquioxane is large, a stable silicon dioxide carbon layer can be formed at high temperature, oxygen and heat are effectively isolated, and therefore combustion is prevented. The flame retardant is compounded with the composite flame retardant, and the flame retardance of the fatigue-resistant composite material is further enhanced through the synergistic effect of the two.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of rubber materials, and particularly relates to a fatigue-resistant composite material based on perfluorinated rubber and a preparation method thereof. BACKGROUND

[0002] Perfluorinated rubber has excellent heat resistance, chemical corrosion resistance and weather resistance, and is widely used in many industrial fields. However, in some high-strength and high-frequency mechanical use environments, fatigue failure problems easily occur, which limits the further expansion of its application range. At present, the modification research of perfluorinated rubber is mostly focused on improving the chemical corrosion resistance, but there are few studies on improving the fatigue resistance and flame retardance. The perfluorinated rubber prepared by using the existing method has the problems of poor fatigue resistance and poor flame retardance while improving the chemical corrosion resistance.

[0003] In order to solve the above problems and improve the fatigue resistance of perfluorinated rubber, the present application provides a fatigue-resistant composite material based on perfluorinated rubber and a preparation method thereof. SUMMARY

[0004] The present application aims to provide a fatigue-resistant composite material based on perfluorinated rubber and a preparation method thereof to solve the problems in the prior art.

[0005] To achieve the above-mentioned purpose, the present application provides the following technical scheme:

[0006] A preparation method of a fatigue-resistant composite material based on perfluorinated rubber, comprising the following steps:

[0007] Step 1: Take the aminated cage-type silsesquioxane and toluene, stir for 30-40 min, add the composite flame retardant, heat to 60-65 DEG C, stir for 1-2 h, filter, wash, dry, and obtain the cage-type silsesquioxane loaded with the flame retardant;

[0008] Step 2: Take the perfluoroether rubber, epoxidized perfluoroether rubber and phthalate, mix uniformly, mix for 50-70 s, add the cage-type silsesquioxane loaded with the flame retardant, carbon black, zinc oxide, calcium hydroxide, triphenyl phosphate and antioxidant, mix for 90-120 s, add the vulcanizing agent, and perform hammer mixing at 120-130 DEG C for 60-80 s, unload, pass through the roller and sheeting to obtain the mixed rubber; heat the mixed rubber to 155-165 DEG C, vulcanize for 5-12 min, and obtain the fatigue-resistant composite material based on perfluorinated rubber.

[0009] More preferably, the fatigue-resistant composite material based on perfluorinated rubber comprises the following components in parts by weight: 80-90 parts of epoxidized perfluoroether rubber, 1-1.6 parts of phthalate, 5-8 parts of cage silsesquioxane loaded with flame retardant, 8-12 parts of carbon black, 1-2 parts of zinc oxide, 1-1.2 parts of calcium hydroxide, 0.2-0.3 parts of triphenyl phosphate, 1-2 parts of vulcanizing agent, and 1-2 parts of antioxidant.

[0010] More preferably, the preparation method of the composite flame retardant comprises the following steps: mixing methanol and deionized water, adding sodium dodecyl benzene sulfonate and stirring uniformly, adding phytic acid modified piperazine salt and stirring for 2-3 hours, adding a citric acid monohydrate solution dropwise to adjust the pH value to 6.5 to obtain a mixed solution; stirring iron modified cysteine complex and deionized water uniformly, adding a sodium hydroxide solution dropwise to adjust the pH value to 9.0, adding the mixed solution, stirring for 2-3 hours, centrifuging, washing and drying to obtain the composite flame retardant.

[0011] More preferably, the preparation method of the phytic acid modified piperazine salt comprises the following steps: stirring phytic acid and anhydrous ethanol uniformly to obtain a phytic acid solution; stirring piperazine and anhydrous ethanol uniformly, adding the phytic acid solution dropwise, stirring for 3-4 hours, and then filtering, washing and drying to obtain the phytic acid modified piperazine salt.

[0012] More preferably, the preparation method of the aminated cage silsesquioxane comprises the following steps: stirring deionized water, propanol, tetraethylammonium hydroxide and acetonitrile uniformly, adding γ-aminopropyl triethoxysilane dropwise, heating to 60-65 DEG C, stirring for 24-26 hours, adding into tetrahydrofuran for precipitation, centrifuging and drying to obtain the aminated cage silsesquioxane.

[0013] More preferably, the preparation method of the iron modified cysteine complex comprises the following steps: stirring cysteine, ferric ammonium sulfate and deionized water uniformly, adding a sodium hydroxide solution dropwise to adjust the pH value to 9.0, reacting for 22-24 hours, and then centrifuging, washing and drying to obtain the iron modified cysteine complex.

[0014] More preferably, the preparation method of the epoxidized perfluoroether rubber comprises the following steps: cutting perfluoroether rubber, adding n-hexane and stirring uniformly to obtain a perfluoroether rubber glue solution, adding meta-chloro peroxybenzoic acid, stirring for 1-2 hours, washing to neutral, using ethanol flocculation, and drying to obtain the epoxidized perfluoroether rubber.

[0015] More preferably, the vulcanizing agent is sulfur, and the antioxidant is antioxidant 1076.

[0016] Compared with the prior art, the present application has the following beneficial effects:

[0017] 1. This invention prepares an iron-modified cysteine ​​complex, introducing iron ions, which possess flame-retardant and catalytic properties, into the flame-retardant system. Iron ions exhibit catalytic properties, promoting the carbonization reaction of perfluororubber fatigue-resistant composite materials during combustion and improving flame retardancy.

[0018] Phytic acid-modified piperazine salt was prepared by salt formation reaction using phytic acid and piperazine. This phytic acid-modified piperazine salt was then compounded with an iron-modified cysteine ​​complex to obtain a composite flame retardant. The composite flame retardant was loaded onto an aminated cage-like silsesquioxane. The aminated cage-like silsesquioxane has a large specific surface area and can form a stable silica carbon layer at high temperatures, effectively isolating oxygen and heat, thereby preventing combustion. When combined with the composite flame retardant, the two work synergistically to further enhance the flame retardancy of the fatigue-resistant composite material.

[0019] 2. This invention uses m-chloroperoxybenzoic acid to prepare an epoxidized perfluoroether rubber, which enhances the air tightness, adhesion, and compatibility with cage-like silsesquioxanes loaded with amino groups as flame retardants, thereby enhancing the mechanical properties and flame retardancy of the composite material. Detailed Implementation

[0020] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0021] The sources and types of raw materials involved in this invention are not particularly limited, and include, for example: perfluoroether rubber: PFE-131TZ type perfluoroether rubber produced by 3M Company of the United States; carbon black: N220 type carbon black.

[0022] Example 1: A method for preparing a fatigue-resistant composite material based on perfluororubber, comprising the following steps:

[0023] Step 1: Preparation of iron-modified cysteine ​​complex:

[0024] Take 15g of cysteine, 9g of ferric ammonium sulfate, and 200mL of deionized water, stir well, add 1.25mol / L sodium hydroxide solution dropwise, adjust the pH to 9.0, react for 23h, centrifuge, wash, and dry to obtain iron-modified cysteine ​​complex.

[0025] Step 2: Preparation of amination-modified cage-like silsesquioxanes:

[0026] Take 30 mL of deionized water, 10 mL of propanol, 2.5 mL of tetraethylammonium hydroxide, 5 mL of acetonitrile, stir evenly, add 50 g of γ-aminopropyl triethoxysilane, heat to 62°C, stir for 25 h, precipitate in 300 mL of tetrahydrofuran, centrifuge, dry, to obtain aminated cage silsesquioxane;

[0027] Step three: preparation of a composite flame retardant:

[0028] Take 10 g of phytic acid, 50 mL of anhydrous ethanol, stir evenly to obtain a phytic acid solution; take 4 g of piperazine, 50 mL of anhydrous ethanol, stir evenly, add the phytic acid solution dropwise, stir for 3.5 h, filter, wash, dry to obtain a phytic acid modified piperazine salt;

[0029] Take 30 mL of methanol, 90 mL of deionized water, mix evenly, add 0.3 g of sodium dodecyl benzene sulfonate, stir evenly, add 5 g of phytic acid modified piperazine salt, stir for 2.5 h, add a 1 mol / L citric acid monohydrate solution dropwise, adjust the pH value to 6.5 to obtain a mixed solution; take 5 g of iron modified cysteine complex, 100 mL of deionized water, stir evenly, add a 1.25 mol / L sodium hydroxide solution dropwise, adjust the pH value to 9.0, add the mixed solution, stir for 2.5 h, centrifuge, wash, dry to obtain a composite flame retardant;

[0030] Step four: preparation of cage silsesquioxane loaded with a flame retardant:

[0031] Take 2 g of aminated cage silsesquioxane, 50 mL of toluene, stir for 35 min, add 0.6 g of a composite flame retardant, heat to 62°C, stir for 1.5 h, filter, wash, dry to obtain cage silsesquioxane loaded with a flame retardant;

[0032] Step five: preparation of epoxidized perfluoro ether rubber:

[0033] Take 7 g of perfluoro ether rubber, cut into pieces, add 100 mL of n-hexane, stir evenly to obtain a perfluoro ether rubber solution, add 16 g of meta-chloroperoxybenzoic acid, stir for 1.5 h, wash to neutral, use ethanol to flocculate, dry to obtain epoxidized perfluoro ether rubber;

[0034] Step six: preparation of a fatigue resistant composite material based on perfluoro rubber:

[0035] Take epoxidized perfluoroether rubber, phthalate, mix evenly, mix 60s, add cage silsesquioxane loaded with flame retardant, carbon black, zinc oxide, calcium hydroxide, triphenyl phosphate, antioxidant 1076, mix 100s, add vulcanizing agent sulfur, hammer mixing at 125℃ for 70s, unload, roll, and get out of the sheet to get the rubber compound; The rubber compound is heated to 160℃, and the vulcanization is carried out under the pressure of 15MPa for 10min to obtain the fatigue-resistant composite material based on perfluoroelastomer;

[0036] The fatigue-resistant composite material based on perfluoroelastomer comprises the following components by weight: 85 parts of epoxidized perfluoroether rubber, 1.2 parts of phthalate, 7 parts of cage silsesquioxane loaded with flame retardant, 10 parts of carbon black, 1.5 parts of zinc oxide, 1.1 parts of calcium hydroxide, 0.25 parts of triphenyl phosphate, 1.5 parts of vulcanizing agent, and 1.5 parts of antioxidant.

[0037] Example 2: A method for preparing a fatigue-resistant composite material based on perfluoroelastomer, comprising the following steps:

[0038] Step one: preparation of iron-modified cysteine complex:

[0039] Take 15g of cysteine, 9g of ferric ammonium sulfate, 200mL of deionized water, stir evenly, add dropwise 1.25mol / L sodium hydroxide solution, adjust pH to 9.0, react for 22h, centrifuge, wash, dry to obtain iron-modified cysteine complex;

[0040] Step two: preparation of aminated cage silsesquioxane:

[0041] Take 30mL of deionized water, 10mL of propanol, 2.5mL of tetraethylammonium hydroxide, 5mL of acetonitrile, stir evenly, add dropwise 50g of γ-aminopropyl triethoxysilane, heat to 60℃, stir for 24h, add to 300mL of tetrahydrofuran, precipitate, centrifuge, dry to obtain aminated cage silsesquioxane;

[0042] Step three: preparation of a composite flame retardant:

[0043] Preparation of phytic acid-modified piperazine salt:

[0044] Take 10g of phytic acid, 50mL of anhydrous ethanol, stir evenly to obtain a phytic acid solution; Take 4g of piperazine, 50mL of anhydrous ethanol, stir evenly, add dropwise the phytic acid solution, stir for 3h, filter, wash, dry to obtain the phytic acid-modified piperazine salt;

[0045] Take 30 mL of methanol, 90 mL of deionized water, mix evenly, add 0.3 g of sodium dodecyl benzene sulfonate, stir evenly, add 5 g of phytic acid modified piperazine salt, stir for 2 h, add 1 mol / L citric acid monohydrate solution, adjust the pH value to 6.5, and obtain a mixed solution; take 5 g of iron modified cysteine complex, 100 mL of deionized water, stir evenly, add 1.25 mol / L sodium hydroxide solution, adjust the pH value to 9.0, add the mixed solution, stir for 2 h, centrifuge, wash, and dry to obtain a composite flame retardant;

[0046] Step four: preparation of cage silsesquioxane loaded with flame retardant:

[0047] Take 2 g of aminated cage silsesquioxane, 50 mL of toluene, stir for 30 min, add 0.6 g of composite flame retardant, heat to 60℃, stir for 1 h, filter, wash, and dry to obtain cage silsesquioxane loaded with flame retardant;

[0048] Step five: preparation of epoxidized perfluoro ether rubber:

[0049] Take 7 g of perfluoro ether rubber, cut into pieces, add 100 mL of n-hexane, stir evenly to obtain a perfluoro ether rubber solution, add 16 g of m-chloroperbenzoic acid, stir for 1 h, wash to neutral, use ethanol to flocculate, and dry to obtain epoxidized perfluoro ether rubber;

[0050] Step six: preparation of fatigue-resistant composite material based on perfluoro rubber:

[0051] Take the epoxidized perfluoro ether rubber, phthalate, mix evenly, mix for 50 s, add cage silsesquioxane loaded with flame retardant, carbon black, zinc oxide, calcium hydroxide, triphenyl phosphate, antioxidant 1076, mix for 90 s, add sulfur as a vulcanizing agent, and perform hammer mixing at 120℃ for 60 s, unload, pass through rollers, and extrude to obtain a mixed rubber; heat the mixed rubber to 155℃, vulcanize under a pressure of 10 MPa for 5 min to obtain a fatigue-resistant composite material based on perfluoro rubber;

[0052] The fatigue-resistant composite material based on perfluoro rubber comprises the following components in terms of weight fraction: 80 parts of epoxidized perfluoro ether rubber, 1 part of phthalate, 5 parts of cage silsesquioxane loaded with flame retardant, 8 parts of carbon black, 1 part of zinc oxide, 1 part of calcium hydroxide, 0.2 parts of triphenyl phosphate, 1 part of vulcanizing agent, and 1 part of antioxidant.

[0053] Example 3: A method for preparing a fatigue-resistant composite material based on perfluoro rubber, comprising the following steps:

[0054] Step one: preparation of iron modified cysteine complex:

[0055] Take 15g cysteine, 9g ferric ammonium sulfate, 200mL deionized water, stir evenly, drop 1.25mol / L concentration of sodium hydroxide solution, adjust the pH value to 9.0, reaction for 24h, centrifugal, washing, drying, get iron modified cysteine complex;

[0056] Step two: preparation of aminated cage silsesquioxane:

[0057] Take 30mL deionized water, 10mL propyl alcohol, 2.5mL tetraethylammonium hydroxide, 5mL acetonitrile, stir evenly, drop 50g γ-aminopropyl triethoxysilane, temperature to 65℃, stirring 26h, add to 300mL tetrahydrofuran precipitation, centrifugal, drying, get aminated cage silsesquioxane;

[0058] Step three: preparation of composite flame retardant:

[0059] Preparation of phytic acid modified piperazine salt:

[0060] Take 10g phytic acid, 50mL anhydrous ethanol, stir evenly, get phytic acid solution; take 4g piperazine, 50mL anhydrous ethanol, stir evenly, drop phytic acid solution, stirring 4h, suction filtration, washing, drying, get phytic acid modified piperazine salt;

[0061] Take 30mL methanol, 90mL deionized water, mix evenly, add 0.3g sodium dodecyl benzene sulfonate, stir evenly, add 5g phytic acid modified piperazine salt, stirring 3h, drop 1mol / L concentration of citric acid monohydrate solution, adjust the pH value to 6.5, get mixed solution; take 5g iron modified cysteine complex, 100mL deionized water, stir evenly, drop 1.25mol / L concentration of sodium hydroxide solution, adjust the pH value to 9.0, add mixed solution, stirring 3h, centrifugal, washing, drying, get composite flame retardant;

[0062] Step four: preparation of cage silsesquioxane loaded with flame retardant:

[0063] Take 2g aminated cage silsesquioxane, 50mL toluene, stirring 40min, add 0.6g composite flame retardant, temperature to 65℃, stirring 2h, filter, washing, drying, get cage silsesquioxane loaded with flame retardant;

[0064] Step five: preparation of epoxidized perfluoroether rubber:

[0065] Take 7g perfluoroether rubber, cut, add 100mL n-hexane, stir evenly, get perfluoroether rubber glue, add 16g meta-chloroperoxybenzoic acid, stirring 2h, washing to neutral, use ethanol flocculation, drying, get epoxidized perfluoroether rubber;

[0066] Step six: preparation of the fatigue-resistant composite material based on perfluorinated rubber:

[0067] Take the epoxidized perfluoroether rubber, phthalate, mix evenly, mix for 70s, add cage silsesquioxane loaded with flame retardant, carbon black, zinc oxide, calcium hydroxide, triphenyl phosphate, antioxidant 1076, mix for 120s, add vulcanizing agent sulfur, hammer mixing at 130℃ for 80s, unload, roll out the sheet to get the rubber compound; the rubber compound is heated to 165℃, and the fatigue-resistant composite material based on perfluorinated rubber is obtained after vulcanization for 12min under a pressure of 15MPa;

[0068] The fatigue-resistant composite material based on perfluorinated rubber comprises the following components in terms of weight fraction: 90 parts of epoxidized perfluoroether rubber, 1.6 parts of phthalate, 8 parts of cage silsesquioxane loaded with flame retardant, 12 parts of carbon black, 2 parts of zinc oxide, 1.2 parts of calcium hydroxide, 0.3 parts of triphenyl phosphate, 2 parts of vulcanizing agent, and 2 parts of antioxidant.

[0069] Comparative example 1: no addition of phytic acid modified piperazine salt, and the rest is the same as example 1:

[0070] Step one: preparation of iron modified cysteine complex:

[0071] Take 15g of cysteine, 9g of ferric ammonium sulfate, 200mL of deionized water, stir evenly, add dropwise sodium hydroxide solution with a concentration of 1.25mol / L, adjust the pH value to 9.0, react for 23h, centrifuge, wash, and dry to obtain the iron modified cysteine complex;

[0072] Step two: preparation of aminated cage silsesquioxane:

[0073] Take 30mL of deionized water, 10mL of propanol, 2.5mL of tetraethylammonium hydroxide, 5mL of acetonitrile, stir evenly, add dropwise 50g of γ-aminopropyl triethoxysilane, heat to 62℃, stir for 25h, add to 300mL of tetrahydrofuran to precipitate, centrifuge, and dry to obtain the aminated cage silsesquioxane;

[0074] Step three: preparation of cage silsesquioxane loaded with flame retardant:

[0075] Take 2g of aminated cage silsesquioxane, 50mL of toluene, stir for 35min, add 0.6g of iron modified cysteine complex, heat to 62℃, stir for 1.5h, filter, wash, and dry to obtain the cage silsesquioxane loaded with flame retardant;

[0076] Step four: preparation of epoxidized perfluoroether rubber:

[0077] Take 7g perfluoroether rubber, cut into pieces, add 100mL of n-hexane, stir evenly to obtain perfluoroether rubber glue, add 16g of m-chloroperbenzoic acid, stir for 1.5h, wash until neutral, use ethanol flocculation, dry to obtain epoxidized perfluoroether rubber;

[0078] Step five: preparation of fatigue-resistant composite material based on perfluoro rubber:

[0079] Take the epoxidized perfluoroether rubber, phthalate, mix evenly, mix for 60s, add the cage silsesquioxane loaded with flame retardant, carbon black, zinc oxide, calcium hydroxide, triphenyl phosphate, antioxidant 1076, mix for 100s, add sulfur as vulcanizing agent, hammer mixing at 125℃ for 70s, unload, pass through the roller and sheeting to obtain the rubber compound; heat the rubber compound to 160℃, and vulcanize under a pressure of 15MPa for 10min to obtain the fatigue-resistant composite material based on perfluoro rubber;

[0080] The fatigue-resistant composite material based on perfluoro rubber comprises the following components in terms of weight fraction: 85 parts of epoxidized perfluoroether rubber, 1.2 parts of phthalate, 7 parts of cage silsesquioxane loaded with flame retardant, 10 parts of carbon black, 1.5 parts of zinc oxide, 1.1 parts of calcium hydroxide, 0.25 parts of triphenyl phosphate, 1.5 parts of vulcanizing agent, and 1.5 parts of antioxidant.

[0081] Comparative example 2: the perfluoroether rubber is not subjected to epoxidation treatment, and the rest is the same as example 1:

[0082] Step one: preparation of iron-modified cysteine complex:

[0083] Take 15g of cysteine, 9g of ferric ammonium sulfate, and 200mL of deionized water, stir evenly, add sodium hydroxide solution with a concentration of 1.25mol / L, adjust the pH value to 9.0, react for 23h, centrifuge, wash, and dry to obtain the iron-modified cysteine complex;

[0084] Step two: preparation of aminated cage silsesquioxane:

[0085] Take 30mL of deionized water, 10mL of propanol, 2.5mL of tetraethylammonium hydroxide, and 5mL of acetonitrile, stir evenly, add 50g of γ-aminopropyl triethoxysilane, heat to 62℃, stir for 25h, add to 300mL of tetrahydrofuran to precipitate, centrifuge, and dry to obtain the aminated cage silsesquioxane;

[0086] Step three: preparation of a composite flame retardant:

[0087] Take 10g phytic acid, 50mL anhydrous ethanol, stir evenly, get phytic acid solution; take 4g piperazine, 50mL anhydrous ethanol, stir evenly, drop phytic acid solution, stir 3.5h, filter, wash, dry, get phytic acid modified piperazine salt;

[0088] Take 30mL methanol, 90mL deionized water, mix evenly, add 0.3g sodium dodecyl benzene sulfonate, stir evenly, add 5g phytic acid modified piperazine salt, stir 2.5h, drop 1mol / L citric acid monohydrate solution, adjust pH value to 6.5, get mixed solution; take 5g iron modified cysteine compound, 100mL deionized water, stir evenly, drop 1.25mol / L sodium hydroxide solution, adjust pH value to 9.0, add mixed solution, stir 2.5h, centrifugal, wash, dry, get composite flame retardant;

[0089] Step four: preparation of cage silsesquioxane loaded with flame retardant:

[0090] Take 2g aminated cage silsesquioxane, 50mL toluene, stir 35min, add 0.6g composite flame retardant, warm up to 62℃, stir 1.5h, filter, wash, dry, get cage silsesquioxane loaded with flame retardant;

[0091] Step five: preparation of perfluorinated rubber based fatigue resistant composite material:

[0092] Take perfluoroether rubber, phthalate, mix evenly, mix 60s, add cage silsesquioxane loaded with flame retardant, carbon black, zinc oxide, calcium hydroxide, triphenyl phosphate, antioxidant 1076, mix 100s, add vulcanizing agent sulfur, hammer mix 70s at 125℃, unload, pass through roller, get out sheet to get rubber compound; warm up rubber compound to 160℃, under 15MPa pressure, vulcanize 10min, get perfluorinated rubber based fatigue resistant composite material;

[0093] The perfluorinated rubber based fatigue resistant composite material comprises the following components, in terms of weight fraction: 85 parts of perfluoroether rubber, 1.2 parts of phthalate, 7 parts of cage silsesquioxane loaded with flame retardant, 10 parts of carbon black, 1.5 parts of zinc oxide, 1.1 parts of calcium hydroxide, 0.25 parts of triphenyl phosphate, 1.5 parts of vulcanizing agent, 1.5 parts of antioxidant.

[0094] Comparative example 3: do not add iron modified cysteine compound, the rest is the same as example 1:

[0095] Step one: preparation of aminated cage silsesquioxane:

[0096] Take 30 mL of deionized water, 10 mL of propanol, 2.5 mL of tetraethylammonium hydroxide, 5 mL of acetonitrile, stir evenly, add 50 g of γ-aminopropyl triethoxysilane, heat to 62℃, stir for 25 h, add to 300 mL of tetrahydrofuran to precipitate, centrifuge, dry, to obtain aminated cage silsesquioxane;

[0097] Step two: preparation of a composite flame retardant:

[0098] Take 10 g of phytic acid, 50 mL of anhydrous ethanol, stir evenly to obtain a phytic acid solution; take 4 g of piperazine, 50 mL of anhydrous ethanol, stir evenly, add the phytic acid solution dropwise, stir for 3.5 h, filter, wash, dry to obtain a phytic acid modified piperazine salt;

[0099] Step three: preparation of cage silsesquioxane loaded with flame retardant:

[0100] Take 2 g of aminated cage silsesquioxane, 50 mL of toluene, stir for 35 min, add 0.6 g of phytic acid modified piperazine salt, heat to 62℃, stir for 1.5 h, filter, wash, dry to obtain cage silsesquioxane loaded with flame retardant;

[0101] Step four: preparation of epoxidized perfluoro ether rubber:

[0102] Take 7 g of perfluoro ether rubber, cut into pieces, add 100 mL of n-hexane, stir evenly to obtain a perfluoro ether rubber solution, add 16 g of m-chloroperbenzoic acid, stir for 1.5 h, wash to neutral, use ethanol to flocculate, dry to obtain epoxidized perfluoro ether rubber;

[0103] Step five: preparation of a fatigue-resistant composite material based on perfluoro rubber:

[0104] Take the epoxidized perfluoro ether rubber, phthalate, mix evenly, mix for 60 s, add the cage silsesquioxane loaded with flame retardant, carbon black, zinc oxide, calcium hydroxide, triphenyl phosphate, antioxidant 1076, mix for 100 s, add the vulcanizing agent sulfur, and mix in a 125℃ press for 70 s, unload, pass through rollers, and out of the sheet to obtain a mixed rubber; heat the mixed rubber to 160℃, and under a pressure of 15 MPa, vulcanize for 10 min to obtain a fatigue-resistant composite material based on perfluoro rubber;

[0105] The fatigue-resistant composite material based on perfluoro rubber comprises the following components in terms of weight fraction: 85 parts of epoxidized perfluoro ether rubber, 1.2 parts of phthalate, 7 parts of cage silsesquioxane loaded with flame retardant, 10 parts of carbon black, 1.5 parts of zinc oxide, 1.1 parts of calcium hydroxide, 0.25 parts of triphenyl phosphate, 1.5 parts of vulcanizing agent, and 1.5 parts of antioxidant.

[0106] Experiment:

[0107] The fatigue-resistant composite materials prepared in Examples 1-3 and Comparative Examples 1-3 were subjected to performance testing; dynamic fatigue performance of the fatigue-resistant composite materials was detected according to GB / T 15584-1995, the pre-load stress was 4900N, the amplitude was ±3mm, and the frequency was 3Hz; the tensile strength was tested according to GB / T 528-2009; and the oxygen index was tested according to GB / T 10707-2008, and the obtained data are shown in Table 1.

[0108] Table 1

[0109] Number of failures Tensile strength (MPa) Limiting oxygen index (%) Example 1 2.15 million times 33 38.3 Example 2 2.12 million times 31 37.7 Example 3 2.16 million times 34 38.6 Comparative Example 1 2.07 million times 30 32.4 Comparative Example 2 1.88 million times 27 34.4 Comparative Example 3 2.10 million times 31 31.8

[0110] Conclusion: From the above data comparison, it can be seen that, in Comparative Example 1, no phytic acid modified piperazine salt was added, and the flame retardance of the fatigue-resistant composite material was greatly reduced. In Comparative Example 2, the perfluoroether rubber was not subjected to epoxidation treatment, and the compatibility of the perfluoroether rubber matrix with the cage silsesquioxane loaded with the flame retardant was poor, and the mechanical properties and the flame retardance of the perfluoroether rubber matrix were both reduced. In Comparative Example 3, no iron modified cysteine complex was added, and the flame retardance of the fatigue-resistant composite material was reduced. In the present application, phytic acid and piperazine are subjected to a salt formation reaction to prepare a phytic acid modified piperazine salt, the phytic acid modified piperazine salt is compounded with an iron modified cysteine complex to obtain a composite flame retardant. The composite flame retardant is loaded on an aminated cage silsesquioxane, the specific surface area of the aminated cage silsesquioxane is large, and a stable silica carbon layer can be formed at high temperature, effectively insulating oxygen and heat, thereby preventing combustion. The composite flame retardant is compounded with the aminated cage silsesquioxane, and the two synergistically act to further enhance the flame retardance of the fatigue-resistant composite material. In Examples 1-3, a kind of epoxidized perfluoroether rubber is prepared using meta-chloroperoxybenzoic acid, the air tightness, adhesion and compatibility with the cage silsesquioxane loaded with the flame retardant having an amino group are enhanced, thereby enhancing the mechanical properties and the flame retardance of the composite material.

[0111] It is apparent for those skilled in the art that the present application is not limited to the details of the foregoing exemplary embodiments, and that the present application can be implemented in other particular forms without departing from the spirit or essential characteristics of the present application. Therefore, the embodiments should be considered in all respects as illustrative and not restrictive, the scope of the present application being defined by the appended claims rather than by the foregoing description, and all changes which come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein.

Claims

1. A method for the preparation of a fatigue resistant composite based on perfluoroelastomer, characterized by: The method comprises the following steps: Step 1: Take the aminated cage silsesquioxane and toluene, stir for 30-40 min, add the composite flame retardant, heat to 60-65 DEG C, stir for 1-2 h, filter, wash, dry, and obtain the cage silsesquioxane loaded with the flame retardant; Step 2: Take the epoxidized perfluoro ether rubber and phthalate, mix uniformly, mix for 50-70 s, add the cage silsesquioxane loaded with the flame retardant, carbon black, zinc oxide, calcium hydroxide, triphenyl phosphate, antioxidant, mix for 90-120 s, add the vulcanizing agent, and hammer mix at 120-130 DEG C for 60-80 s, unload, pass through rollers, and obtain the rubber compound; heat the rubber compound to 155-165 DEG C, vulcanize for 5-12 min, and obtain the perfluoro rubber-based fatigue-resistant composite material.

2. A method of preparing a perfluoroelastomer-based fatigue resistant composite according to claim 1, characterized in that: The perfluoro rubber-based fatigue-resistant composite material comprises the following components in parts by weight: 80-90 parts of epoxidized perfluoro ether rubber, 1-1.6 parts of phthalate, 5-8 parts of cage silsesquioxane loaded with the flame retardant, 8-12 parts of carbon black, 1-2 parts of zinc oxide, 1-1.2 parts of calcium hydroxide, 0.2-0.3 parts of triphenyl phosphate, 1-2 parts of the vulcanizing agent, and 1-2 parts of the antioxidant.

3. A method of preparing a perfluoroelastomer-based fatigue resistant composite according to claim 1, characterized in that: The preparation method of the composite flame retardant is as follows: take methanol and deionized water, mix uniformly, add sodium dodecyl benzene sulfonate, stir uniformly, add the phytic acid modified piperazine salt, stir for 2-3 h, drop a citric acid monohydrate solution, adjust the pH value to 6.5, and obtain a mixed solution; take the iron modified cysteine complex and deionized water, stir uniformly, drop a sodium hydroxide solution, adjust the pH value to 9.0, add the mixed solution, stir for 2-3 h, centrifuge, wash, and dry, and obtain the composite flame retardant.

4. A method of producing a perfluoroelastomer-based fatigue-resistant composite material according to claim 3, characterized in that: The preparation method of the phytic acid modified piperazine salt is as follows: take phytic acid and anhydrous ethanol, stir uniformly, and obtain a phytic acid solution; take piperazine and anhydrous ethanol, stir uniformly, drop the phytic acid solution, stir for 3-4 h, filter, wash, and dry, and obtain the phytic acid modified piperazine salt.

5. The method for preparing a fatigue-resistant composite material based on perfluororubber according to claim 1, characterized in that: The preparation method of the aminated cage silsesquioxane is as follows: take deionized water, propanol, tetraethylammonium hydroxide, and acetonitrile, stir uniformly, drop gamma-aminopropyl triethoxysilane, heat to 60-65 DEG C, stir for 24-26 h, add to tetrahydrofuran for precipitation, centrifuge, and dry, and obtain the aminated cage silsesquioxane.

6. A method of making a perfluoroelastomer-based fatigue resistant composite according to claim 3, characterized in that: The preparation method of the iron modified cysteine complex is as follows: take cysteine, ferric ammonium sulfate, and deionized water, stir uniformly, drop a sodium hydroxide solution, adjust the pH value to 9.0, react for 22-24 h, centrifuge, wash, and dry, and obtain the iron modified cysteine complex.

7. The method for preparing a fatigue-resistant composite material based on perfluororubber according to claim 2, characterized in that: The preparation method of the epoxidized perfluoro ether rubber is as follows: take perfluoro ether rubber, cut, add n-hexane, stir uniformly, obtain a perfluoro ether rubber solution, add meta-chloro peroxide benzoic acid, stir for 1-2 h, wash to neutral, use ethanol flocculation, and dry, and obtain the epoxidized perfluoro ether rubber.

8. The method for preparing a fatigue-resistant composite material based on perfluororubber according to claim 2, characterized in that: The vulcanizing agent is sulfur; and the antioxidant is antioxidant 1076.

9. A perfluoroelastomer-based fatigue-resistant composite material prepared according to the method of any one of claims 1-8.