CN108017746B - Peroxide vulcanized fluororubber with low compression set and preparation method thereof - Google Patents
Peroxide vulcanized fluororubber with low compression set and preparation method thereof Download PDFInfo
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Abstract
The invention relates to a preparation method of peroxide vulcanized fluororubber with low compression permanent deformation, which selects fluorine-containing composite emulsifier as emulsifier in the process of preparing peroxide vulcanized fluororubber by intermittent emulsion method; the fluorine-containing composite emulsifier microemulsion is a mixture of a carboxyl-containing perfluoropolyether surfactant and a nonionic fluorocarbon surfactant, and the mass ratio of the carboxyl-containing perfluoropolyether surfactant to the nonionic fluorocarbon surfactant is 1: 0.4-0.7. Furthermore, by selecting a bromine-containing vulcanization point monomer, selecting an iodine-containing chain transfer agent and controlling the adding time of the chain transfer agent, the compression set value of the fluororubber can be further reduced, the tensile strength of the fluororubber is enhanced, and the excellent mechanical and dielectric properties, heat resistance and the like of the fluororubber are ensured.
Description
Technical Field
The invention relates to the field of fluororubber synthesis, in particular to fluororubber with low compression set and a preparation method thereof.
Background
Fluororubbers have excellent heat resistance, good chemical and physical mechanical properties, electrical insulation properties and radiation resistance, and become indispensable and irreplaceable base materials in modern industries, particularly in high-tech fields. As is well known, as a rubber seal, a low compression set is one of the main properties to ensure its sealing ability. Fluororubbers, which are elastomers excellent in high-temperature resistance and dielectric resistance, are mainly used as movable and stationary seals, and are required to have a low compression set value. Since the 20 th century and 50 th century of the emergence of raw fluororubbers, researches on matching technologies focus on reducing the compression permanent deformation performance of the rubber compound for a long time, wherein the researches comprise improvement of a raw fluororubber synthesis process, addition of different vulcanization systems and the like. However, after vulcanization by peroxide, the compression set value is still more than 19%, and the sealing material cannot be used for movable or fixed sealing elements working in petroleum and lubricating oil, fuel oil, hydraulic oil and diester synthetic lubricating oil.
Chinese patent 1989202a discloses a peroxide-curable fluoroelastomer composition, which mainly introduces that the flowability of a fluoroelastomer composition having a disadvantage in productivity is greatly modified to improve processability, but the obtained fluoroelastomer has a number average molecular weight of only 3 to 7 ten thousand, insufficient crosslinking density, long vulcanization time and a large compression set value.
Chinese patent CN1665852A discloses a peroxide-curable elastomer, which adopts CH2= CH- (CF2) nI (n = 2-8) and takes 4-iodine-3, 3,4, 4-tetrafluorobutene-1 as a representative substance as a vulcanization point monomer, and RIx (R is a perfluoroalkyl group with 3-10 carbon atoms, and X = 1-2) as a chain transfer agent. Although the number average molecular weight reaches the requirement, the chain transfer agent is added in batches, and a certain concentration is maintained, so that the obtained product has narrow relative molecular weight distribution, poor fluidity and large compression set value.
Disclosure of Invention
The invention aims to provide a preparation method of peroxide vulcanized fluororubber with low compression set, which comprises the following steps: selecting a fluorine-containing composite emulsifier, and preparing peroxide vulcanized fluororubber by an intermittent emulsion method;
the fluorine-containing composite emulsifier microemulsion is a mixture of a carboxyl-containing perfluoropolyether surfactant and a nonionic fluorocarbon surfactant, and the mass ratio of the carboxyl-containing perfluoropolyether surfactant to the nonionic fluorocarbon surfactant is 1: 0.4-0.7.
The fluorine-containing composite emulsifier microemulsion not only contains carboxyl, plays a good anti-scorching role during vulcanization, but also has little influence on physical and mechanical properties; in addition, polar carboxyl is also alternately contained in the composite emulsifier microemulsion, so that the distance of the ionic end group chain segment contained on the main chain of the fluoroelastomer is increased, the vulcanization time is shortened, and the two substances are mixed, so that the compression set value is reduced, and the tensile strength is increased.
Preferably, the carboxyl group-containing perfluoropolyether surfactant is C4F9OCF2COOH、C4F9OCF(CF2)COOH、C4F9OC2F4OCF2COOH or C3F7OC2F4OCF2COOH；
And/or the nonionic fluorocarbon surfactant is polyoxyethylene fatty alcohol ether, polyoxyethylene fatty acid ester or polysorbate.
Preferably, the number average molecular weight Mn of the fluorine-containing composite emulsifier is 400-1000. The emulsifier with low number average molecular weight not only well mixes the two emulsifiers uniformly to form micelles with compatibilization, thereby greatly increasing the dissolved amount of monomers, increasing the stability of monomer droplets, effectively controlling the generation of gel, but also having small steric hindrance and not influencing the reaction between fluoroolefin monomers.
Preferably, the preparation method of the fluorine-containing composite emulsifier is that the perfluoropolyether surfactant and the nonionic surfactant are directly mixed according to the proportion of 1: 0.4-0.7 to obtain the microemulsion, and if the perfluoropolyether surfactant and the nonionic surfactant are mixed in a solid-liquid state, the microemulsion can be heated. Thus, not only can the emulsion with small grain diameter and good stability be better obtained, but also the good emulsification effect can be achieved by using less emulsifier.
Preferably, the polymerized monomer is vinylidene fluoride and/or tetrafluoroethylene and at least one of perfluoropropylene, chlorotrifluoroethylene, perfluoroalkyl vinyl ether, propylene, ethylene or vinyl fluoride.
Preferably, the polymerization monomer is a mixture of tetrafluoroethylene, vinylidene fluoride and perfluoropropylene, and the mass percentages of the tetrafluoroethylene, the vinylidene fluoride and the perfluoropropylene are respectively 5-15%, 30-75% and 15-55%; or the polymerized monomer is a mixture of tetrafluoroethylene and perfluoropropylene, wherein the mass percentage of the tetrafluoroethylene is 35-65%. If the tetrafluoroethylene content is less than 35%, the fluorine-containing elastomer has low strength, poor solvent resistance, small polymerization degree and the like; if the tetrafluoroethylene content is more than 65%, the polymer has high crystallinity and poor elastic properties, and a plastic substance is generated, so that the tetrafluoroethylene-based elastomer cannot be used for vulcanization processing of rubber.
Preferably, in the process of preparing the peroxide vulcanized fluororubber by the batch emulsion method, a bromine-containing vulcanization point monomer is added;
preferably, the bromine-containing cure site monomer is trifluorobromoethylene, 4-bromo-3, 3,4, 4-tetrafluorobutene, 1-bromo-2, 2-difluoroethylene or brominated ethyl vinyl ether, preferably trifluorobromoethylene; the amount of the addition is 0.3 to 1.5% of the total amount of the polymerization monomers. If the content is less than 0.5%, the crosslinking density is poor, the vulcanization effect is poor, and the permanent compression deformation value is influenced; and more than 2%, a large number of crosslinking points are present, and the vulcanization speed is improved, but other properties of the product are affected.
Preferably, the chain transfer agent containing iodine is selected from one or more of iodoethane, 1, 2-diiodoethane, 1, 3-diiodoperfluoropropane, 1, 3-diiodo-2-chloroperfluoropropane and 1, 4-diiodoperfluorobutane; preferably 1, 4-diiodoperfluorobutane; the addition amount is 0.2-1% of the weight of the fluororubber. If the amount of iodine is more than 1% by weight of the fluororubber, the polymerization rate is greatly decreased to deteriorate the productivity, and if the amount of the initiator is increased to improve the productivity, the non-iodine ends are relatively increased to deteriorate the vulcanizate properties. If the content is less than 0.2%, the effective vulcanization point is small, and the vulcanization speed is slow.
Adding bromine-containing sulfide point monomer and iodine-containing chain transfer agent to generate bromine or iodine-containing end group on main chain, and generating-CH when most peroxide is decomposed3The radical, it and rubber containing iodine or bromine carry on the fast crosslinking, the vulcanized rubber got has fine mechanics and dielectric properties, performance such as the heat-resisting.
Preferably, the method of the present invention comprises the steps of:
1) adding deionized water, a pH buffering agent, a fluorine-containing composite emulsifier and a bromine-containing vulcanization point monomer into a reaction kettle, uniformly mixing, and then vacuumizing the reaction kettle;
2) adjusting the temperature of the reaction kettle to be 30-100 ℃; adding a polymerization monomer into the reaction kettle until the pressure in the reaction kettle is 1-4 MPa, adding an initiator for reaction, adding an iodine-containing chain transfer agent when the conversion rate of the polymerization monomer is 5-35%, and supplementing the polymerization monomer in the reaction process to keep the pressure in the reaction kettle constant;
3) after the reaction is finished, the polymer is subjected to electrolyte coagulation, and then is washed and dried;
preferably, when the conversion rate of the polymerized monomer is 10-30%, an iodine-containing chain transfer agent is added.
The additional polymerized monomer is a monomer having the same composition as the polymerized monomer species, wherein the amount ratio of the different species may be the same as or different from the polymerized monomer species, which is adjusted depending on the extent of the reaction.
The reaction is finished at a time according to the solid content of the emulsion generated in the reaction container, and the reaction is generally finished when the solid content in the reaction container reaches 25-35%.
Preferably, the addition amount of the fluorine-containing composite emulsifier is 0.001-5% of the mass of the deionized water. The proper amount of emulsifier is needed, too much will affect the performance of the polymer coating film, and too little will result in instability of the polymer emulsion and even failure of the polymerization.
Preferably, the initiator is an organic or inorganic peroxide or azo compound; preferably persulfate, peroxycarbonate or a mixture of persulfate, ferrous ion and sulfite; further preferably potassium persulfate or ammonium persulfate; the addition amount of the initiator is 0.01-3% of 100 parts by weight of the aqueous medium. When the dosage of the initiator is less than 0.01 percent, the initiator cannot play a role in initiation, the reaction is too slow, the efficiency is low and the like; at levels above 3%, a large number of free radicals are produced, the reaction is too fast to control, and unstable, while the faster the chain termination, a large number of small molecular weight products are produced, which have an effect on polymer properties.
Preferably, the pH buffering agent is selected from one or more of dipotassium hydrogen phosphate, disodium hydrogen phosphate, borax or sodium bicarbonate.
Preferably, the temperature of the polymerization reaction is 60-80 ℃, and the pressure is 2-3 MPa. The polymerization reaction temperature is 30-100 ℃, if the temperature is lower than 30 ℃, the copolymerization speed is too slow, and the polymerization reaction is not suitable for effective reaction on an industrial scale, but if the temperature is higher than 100 ℃, a large amount of free radicals can be generated too fast, the reaction is too fast, the effective control is not facilitated, the repeated production cannot be realized, and the performance of the product cannot be controlled. The reaction can be better controlled to proceed at 60-80 ℃. If the pressure is less than 1MPa, the monomer concentration in the polymerization system is too low to achieve a satisfactory reaction rate. In addition, the molecular weight cannot be increased effectively. If the pressure is higher than 4MPa, the requirements on equipment, systems and pipelines are higher, and the production cost is increased. The reaction rate is moderate under the pressure of 2-3 MPa, and the molecular weight of the obtained product is more ideal.
During post processing, other optional components, such as fillers, selected from carbon black, graphite, silica, clay, diatomaceous earth, talc, and the like, may also improve compression set.
The fluoroelastomer, organic peroxide, coagent, and any other ingredients are typically introduced into the curable composition of the present invention by an internal mixer or rubber roll mill. The resulting composition may then be shaped (e.g., molded or extruded) and cured.
Another object of the present invention is to protect the peroxide-cured fluororubbers obtained by the process of the invention with low compression set.
The peroxide vulcanized fluororubber of the present invention may further contain an organic peroxide selected from 1, 1-bis (t-butylperoxy) cyclohexane; dicumyl peroxide; 2, 5-dimethyl-2, 5-di-tert-butylperoxyhexane; bis (2, 4-dichlorobenzoyl) peroxide; dibenzoyl peroxide; di-t-butylperoxyisopropyl benzene and triallyl isocyanurate (co-crosslinking agent). Further, the organic peroxide may be used singly or as a mixture of two or more types.
The method has the following beneficial effects:
the method of the invention can effectively reduce the compression set value of the fluororubber and enhance the tensile strength by using the perfluoropolyether composite emulsifier;
furthermore, a bromine-containing vulcanization point monomer is selected, an iodine-containing chain transfer agent is selected, and the adding time of the chain transfer agent is controlled, so that the compression permanent deformation value of the fluororubber can be further reduced, the tensile strength of the fluororubber is enhanced, the excellent mechanical and dielectric properties, heat resistance and other properties of the fluororubber are ensured, and the comprehensive properties of the fluororubber are improved; the final fluoroelastomer has a strength greater than 17MPa and a compression set less than 19%. It is useful in many industrial applications including seals, cable jackets, pipes and laminates.
Detailed Description
For the sake of understanding, the present invention will be described in detail below with reference to specific examples. It is specifically noted that the specific examples are given solely for the purpose of illustration and it will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the spirit of the invention.
The preparation method of the microemulsion containing the fluorine emulsifier used in the following examples is as follows: in a glass reactor equipped with a stirrer, 900g of CF were stirred with appropriate stirring3O(CF2-CF(CF3)O)m（CF2O)nCF3(wherein m/n =20, number average molecular weight 760) and 500g of polyoxyethylene fatty alcohol ether were subjected to preliminary microemulsion to form a fluorine-containing emulsifier.
The performance test method of the fluorine-containing elastomer comprises the following steps:
raw rubber Mooney: ML (1 + 10), as per ASTM D1646, using L (Large) type rotors, at 121 ℃ (unless otherwise specified), with a preheating time of one minute and a rotor on-stream time of 10 minutes.
Wherein, the vulcanization formula is as follows:
100 parts of raw rubber;
3 parts of zinc oxide;
n99025 parts;
4 parts of TAIC;
2.5 parts of 2, 5-dimethyl-2, 5-bis (tert-butylperoxy) hexane.
The first-stage vulcanization is carried out at 168 ℃ for 10min, and the second-stage vulcanization is carried out at 232 ℃ for 4 h.
Test methods for tensile strength and elongation: the standard compound was subjected to 1 press vulcanization and 2 oven vulcanization under standard vulcanization conditions to produce a sheet having a thickness of 2mm, and measured in accordance with JIS-K6251.
Permanent compression set test method: a circular ring (P-24) was produced by subjecting the following standard compound to 1 press vulcanization and 2 oven vulcanization under standard vulcanization conditions 1 or 2, and the compression set after 1 press vulcanization and the compression set after 2 oven vulcanization were measured in accordance with JIS-K6301 (the sample was held at 200 ℃ for 72 hours under 25% press compression and then left in a thermostatic chamber at 25 ℃ for 30 minutes for measurement).
Weight average molecular weight (Mw) and number average molecular weight (Mn):
the device comprises the following steps: HLC-8000 (manufactured by Tosoh corporation)
Showa chromatographic column: GPC KF806M 2 root
GPC KF 8011 root
GPC KF 8021 root
A detector: differential refractive index detector
Developing solvent: tetrahydrofuran (THF)
Temperature: 35 deg.C
Sample concentration: 0.1% by weight
Standard samples: various monodisperse POLYSTYRENEs (Mw/Mn) =1.14(Max), TSK Standard POLYSTYRENE (manufactured by Tosoh corporation)
Example 1
The embodiment relates to a preparation method of peroxide vulcanized fluororubber with low compression set, which comprises the following steps:
1) adding 33.3L of deionized water into a 50L stainless steel vertical reaction kettle, blowing nitrogen and discharging oxygen for three times, vacuumizing until the oxygen content is less than or equal to 25ppm, and adding 80g of fluorine-containing composite emulsifier microemulsion, 20g of dipotassium hydrogen phosphate and 40g of trifluorobromoethylene;
2) starting stirring, raising the speed to 200rpm, heating to 60 ℃, adding 70/10/20 mixed monomers of vinylidene fluoride, tetrafluoroethylene and HFP according to the mass ratio of the materials to 2MPa, adding 10g of potassium persulfate into the reaction kettle through a metering pump after the system is stable, and starting polymerization. Continuously adding mixed monomer to maintain the pressure of the reaction kettle at 2MPa, adding 40g of 1, 4-diiodo perfluorobutane into the reaction kettle when the conversion rate reaches 15%,
3) stopping the reaction until the solid content of the emulsion in the reactor reaches 30 percent, recovering unreacted monomers, and discharging the polymer emulsion. Then adding a small amount of magnesium chloride into the polymer emulsion, pouring off clear water, washing with deionized water until the conductivity of the mother liquor is less than or equal to 5 mu S/cm, drying in a vacuum oven at 120 ℃ for 24 hours, and feeding a sample to be detected. The results are shown in Table 1.
Example 2
The embodiment relates to a preparation method of peroxide vulcanized fluororubber with low compression set, which comprises the following steps:
1) adding 33.3L of deionized water into a 50L stainless steel vertical reaction kettle, blowing nitrogen and discharging oxygen for three times, vacuumizing until the oxygen content is less than or equal to 25ppm, and adding 80g of fluorine-containing composite emulsifier microemulsion, 20g of dipotassium hydrogen phosphate and 40g of trifluorobromoethylene;
2) stirring is started, the speed is 200rpm, the temperature is increased to 60 ℃, mixed monomer with VDF/HFP =55/45 (molar ratio) is added, the pressure is increased to 2MPa at 80 ℃, 10g of 15 percent (wt) ammonium persulfate aqueous solution is pressed in through a metering pump, the polymerization reaction is initiated, then mixed monomer with VDF/HFP =82/18 (molar ratio) is supplemented, and the reaction pressure is maintained to be 2.0 MPa. When the conversion rate reaches 20%, adding 40g of 1, 4-diiodoperfluorobutane into the reaction kettle;
3) stopping the reaction until the solid content of the emulsion in the reactor reaches 30 percent, recovering unreacted monomers, and discharging the polymer emulsion. Then adding a small amount of magnesium chloride into the polymer emulsion, pouring off clear water, washing with deionized water until the conductivity of the mother liquor is less than or equal to 5 mu S/cm, drying in a vacuum oven at 120 ℃ for 24 hours, and feeding a sample to be detected. The results are shown in Table 1.
Example 3
The embodiment relates to a preparation method of peroxide vulcanized fluororubber with low compression set, which comprises the following steps:
1) adding 33.3L of deionized water into a 50L stainless steel vertical reaction kettle, blowing nitrogen and discharging oxygen for three times, vacuumizing until the oxygen content is less than or equal to 25ppm, and adding 80g of fluorine-containing composite emulsifier microemulsion, 20g of dipotassium hydrogen phosphate and 40g of trifluorobromoethylene;
2) stirring was started at 200rpm, the temperature was increased to 60 ℃, the monomer mixture of TFE/VDF/HFP =4/60/36 (molar ratio) was added, the pressure was increased to 2MPa at 80 ℃, 10g of a 15 wt% aqueous ammonium persulfate solution was pumped in by a metering pump to initiate polymerization, and then the monomer mixture of TFE/VDF/HFP =6.3/77.2/16.5 (molar ratio) was added to maintain the reaction pressure at 2.0 MPa. When the conversion rate reaches 30%, adding 40g of 1, 4-diiodoperfluorobutane into the reaction kettle;
3) stopping the reaction until the solid content of the emulsion in the reactor reaches 30 percent, recovering unreacted monomers, and discharging the polymer emulsion. Then adding a small amount of magnesium chloride into the polymer emulsion, pouring off clear water, washing with deionized water until the conductivity of the mother liquor is less than or equal to 5 mu S/cm, drying in a vacuum oven at 120 ℃ for 24 hours, and feeding a sample to be detected. The results are shown in Table 1.
Example 4
The embodiment relates to a preparation method of peroxide vulcanized fluororubber with low compression set, which comprises the following steps:
1) adding 33.3L of deionized water into a 50L stainless steel vertical reaction kettle, blowing nitrogen and discharging oxygen for three times, vacuumizing until the oxygen content is less than or equal to 25ppm, and adding 40g of perfluorooctanoic acid emulsifier microemulsion, 20g of dipotassium hydrogen phosphate and 40g of trifluorobromoethylene;
2) stirring was turned on at 200rpm, the temperature was raised to 60 ℃, the monomer mixture of TFE/VDF/HFP =5/59/36 (molar ratio) was added, the pressure was raised to 2MPa at 80 ℃, 10g of a 15 wt% aqueous ammonium persulfate solution was pumped in by a metering pump to initiate polymerization, and then the monomer mixture of TFE/VDF/HFP =6.5/77/16.5 (molar ratio) was added to maintain the reaction pressure at 2.0 MPa. When the conversion rate reached 25%, 40g of 1, 4-diiodoperfluorobutane was added to the reactor
3) Stopping the reaction until the solid content of the emulsion in the reactor reaches 30 percent, recovering unreacted monomers, and discharging the polymer emulsion. Then adding a small amount of magnesium chloride into the polymer emulsion, pouring off clear water, washing with deionized water until the conductivity of the mother liquor is less than or equal to 5 mu S/cm, drying in a vacuum oven at 120 ℃ for 24 hours, and feeding a sample to be detected. The results are shown in Table 1.
Example 5
This example relates to a process for the preparation of peroxide-cured fluororubbers with a low compression set, which differs from example 3 by changing the initial monomer blend ratio to TFE/VDF/HFP =15:30:55 and the additional monomer blend ratio to TFE/VDF/HFP =18:55: 37. The results are shown in Table 1.
Example 6
The procedure described in example 3 was repeated to synthesize two batches of experiments, the first without chain transfer agent and the second with chain transfer agent at the beginning of the reaction, the two synthesized batches of emulsions were uniformly mixed in different weight ratios to obtain the desired Mooney fluoroelastomer, then coagulant was added, the mixture was washed with deionized water until the mother liquor conductivity was less than or equal to 5. mu.S/cm, dried in a vacuum oven at 120 ℃ for 24 hours, and the sample was sampled and tested. The results are shown in Table 1.
Comparative example 1
The procedure described in example 3 was repeated except that the chain transfer agent was added in a different manner, and 40g of 1, 4-diiodoperfluorobutane was initially charged to the reactor when the conversion was 4%. The results are shown in Table 1.
Comparative example 2
The procedure described in example 3 was repeated, starting with 40g of 1, 4-diiodoperfluorobutane at a conversion of 40%. The results are shown in Table 1.
Comparative example 3
The difference compared with example 3 is that the emulsifier is sodium perfluorooctanoate and the results are shown in Table 1 and Table 1
Comparative example 4
Compared with the embodiment 3, the difference is that the mass ratio of the carboxyl-containing perfluoropolyether surfactant to the nonionic fluorocarbon surfactant in the complexing agent is 1: 0.75 to 1 results are shown in Table 1.
Comparative example 5
The difference compared to example 3 is that the bromine-containing cure site monomer trifluorobromoethylene was not added during the reaction. The results are shown in Table 1.
Comparative example 6
The difference compared to example 3 is that the chain transfer agent is diethyl malonate. The results are shown in Table 1.
TABLE 1
Although the invention has been described in detail hereinabove by way of general description, specific embodiments and experiments, it will be apparent to those skilled in the art that many modifications and improvements can be made thereto based on the invention. Accordingly, such modifications and improvements are intended to be within the scope of the invention as claimed.
Claims (12)
1. A method for preparing peroxide vulcanized fluororubber with low compression set is characterized by comprising the following steps:
1) adding deionized water, a pH buffering agent, a fluorine-containing composite emulsifier and a bromine-containing vulcanization point monomer into a reaction kettle, uniformly mixing, and then vacuumizing the reaction kettle;
2) adjusting the temperature of the reaction kettle to be 30-100 ℃; adding a polymerization monomer into the reaction kettle until the pressure in the reaction kettle is 1-4 MPa, adding an initiator for reaction, adding an iodine-containing chain transfer agent when the conversion rate of the polymerization monomer is 5-35%, and supplementing the polymerization monomer in the reaction process to keep the pressure in the reaction kettle constant;
3) after the reaction is finished, the polymer is subjected to electrolyte coagulation, washed and dried to obtain the low-temperature-resistant perfluoroether elastomer;
the fluorine-containing composite emulsifier is a mixture of a carboxyl-containing perfluoropolyether surfactant and a nonionic surfactant, and the mass ratio of the carboxyl-containing perfluoropolyether surfactant to the nonionic surfactant is 1: 0.4-0.7;
the carboxyl-containing perfluoropolyether surfactant is C4F9OCF2COOH、C4F9OCF(CF2)COOH、C4F9OC2F4OCF2COOH or C3F7OC2F4OCF2COOH; the nonionic surfactant is polyoxyethylene fatty alcohol ether, polyoxyethylene fatty acid ester or polysorbate;
the bromine-containing vulcanization point monomer is trifluorobromoethylene, 4-bromo-3, 3,4, 4-tetrafluorobutene, 1-bromo-2, 2-difluoroethylene or brominated ethyl vinyl ether;
the chain transfer agent containing iodine is one or more of iodoethane, 1, 2-diiodoethane, 1, 3-diiodoperfluoropropane, 1, 3-diiodo-2-chloroperfluoropropane and 1, 4-diiodoperfluorobutane.
2. The method according to claim 1, wherein the monomer to be polymerized is vinylidene fluoride and/or tetrafluoroethylene, and at least one of perfluoropropylene, chlorotrifluoroethylene, perfluoroalkyl vinyl ether, propylene, ethylene, or vinyl fluoride.
3. The preparation method according to claim 2, wherein the polymerized monomer is a mixture of tetrafluoroethylene, vinylidene fluoride and perfluoropropylene, and the mass percentages of the tetrafluoroethylene, the vinylidene fluoride and the perfluoropropylene are respectively 5-15%, 30-75% and 15-55%; or the polymerized monomer is a mixture of tetrafluoroethylene and perfluoropropylene, wherein the mass percentage of the tetrafluoroethylene is 35-65%.
4. The method according to any one of claims 1 to 3, wherein a bromine-containing cure site monomer, trifluorobromoethylene, is added during the production of the peroxide-cured fluororubber by the batch emulsion method.
5. The production method according to any one of claims 1 to 3, wherein the bromine-containing cure site monomer is added in an amount of 0.3 to 1.5% based on the total mass of the polymerized monomers.
6. The production method according to claim 5, wherein in the production of the peroxide-vulcanized fluororubber by the batch emulsion method, an iodine-containing chain transfer agent is selected; 1, 4-diiodoperfluorobutane.
7. The process according to claim 6, wherein the iodine-containing chain transfer agent is added in an amount of 0.2 to 1% based on the total amount of the total species of the polymerization monomers.
8. The preparation method according to claim 7, wherein the addition amount of the fluorine-containing composite emulsifier is 0.001-5% by mass of deionized water.
9. The method according to claim 7 or 8, wherein the initiator is an organic or inorganic peroxide or azo compound.
10. The method according to claim 9, wherein the initiator is a persulfate, a peroxycarbonate, or a mixture of a persulfate with ferrous ions and a sulfite.
11. The production method according to claim 10, wherein the initiator is potassium persulfate or ammonium persulfate; the addition amount of the initiator is 0.01-3% of the mass of the deionized water.
12. The peroxide vulcanized fluororubber prepared by the method according to any one of 1 to 11.
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Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1351616A (en) * | 1999-05-20 | 2002-05-29 | 纳幕尔杜邦公司 | Polymerization of fluoromonomers |
| CN1742027A (en) * | 2003-01-24 | 2006-03-01 | 3M创新有限公司 | Emulsion polymerization of fluorinated monomers |
| CN101605826A (en) * | 2006-11-09 | 2009-12-16 | 纳幕尔杜邦公司 | Use comprises the fluorinated monomer aqueous polymerization reaction that the polymerizing agent of perfluoroalkyl polyether acid or salt and hydrocarbon tensio-active agent carries out |
| CN104448095A (en) * | 2014-12-15 | 2015-03-25 | 中昊晨光化工研究院有限公司 | Preparation method of fluororubber capable of being vulcanized by peroxide |
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| Publication number | Priority date | Publication date | Assignee | Title |
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| CN1351616A (en) * | 1999-05-20 | 2002-05-29 | 纳幕尔杜邦公司 | Polymerization of fluoromonomers |
| CN1742027A (en) * | 2003-01-24 | 2006-03-01 | 3M创新有限公司 | Emulsion polymerization of fluorinated monomers |
| CN101605826A (en) * | 2006-11-09 | 2009-12-16 | 纳幕尔杜邦公司 | Use comprises the fluorinated monomer aqueous polymerization reaction that the polymerizing agent of perfluoroalkyl polyether acid or salt and hydrocarbon tensio-active agent carries out |
| CN104448095A (en) * | 2014-12-15 | 2015-03-25 | 中昊晨光化工研究院有限公司 | Preparation method of fluororubber capable of being vulcanized by peroxide |
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