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CN-122011632-A - Conductive fluororubber modified based on in-situ polymerization ionic liquid-polyurethane and preparation method and application thereof

CN122011632ACN 122011632 ACN122011632 ACN 122011632ACN-122011632-A

Abstract

The invention provides an in-situ polymerization ionic liquid-polyurethane modified conductive fluororubber and a preparation method and application thereof, and belongs to the field of chemical materials. The modified fluororubber is prepared from the following raw materials, by weight, 50-90 parts of fluororubber raw rubber, 10-50 parts of in-situ polymerized ionic liquid-polyurethane modifier, 1-3 parts of vulcanizing agent, 0.5-2 parts of vulcanization accelerator and 2-5 parts of acid absorber, wherein the mass ratio of fluororubber raw rubber to in-situ polymerized ionic liquid-polyurethane modifier is 1:1-9:1, and the in-situ polymerized ionic liquid-polyurethane modifier is prepared by in-situ polymerization of raw materials comprising polyol, isocyanate, chain extender and ionic liquid. According to the invention, the fluororubber with excellent conductivity and mechanical property is prepared by adding the in-situ polymerized ionic liquid-polyurethane modifier and controlling the mass ratio of the ionic liquid-polyurethane modifier to the fluororubber raw rubber, so that the fluororubber has good application prospects in functional devices such as conductive sealing, electrostatic protection, electromagnetic shielding and flexible sensors.

Inventors

  • Xiang Liqiong
  • SHEN WANYING
  • ZHANG JINGWEN

Assignees

  • 四川道弘新材料股份有限公司

Dates

Publication Date
20260512
Application Date
20260330

Claims (10)

  1. 1. The fluororubber is characterized by comprising, by weight, 50-90 parts of fluororubber raw rubber, 10-50 parts of in-situ polymerized ionic liquid-polyurethane modifier, 1-3 parts of vulcanizing agent, 0.5-2 parts of vulcanization accelerator and 2-5 parts of acid absorber, wherein the mass ratio of the fluororubber raw rubber to the in-situ polymerized ionic liquid-polyurethane modifier is 1:1-9:1, and the in-situ polymerized ionic liquid-polyurethane modifier is prepared by in-situ polymerization of raw materials comprising polyol, isocyanate, chain extender and ionic liquid.
  2. 2. The fluororubber according to claim 1, wherein the raw materials further comprise 5-15 parts of reinforcing filler and 0.1-1 part of internal mold release agent.
  3. 3. The fluororubber according to claim 2, wherein said vulcanizing agent is at least one selected from the group consisting of 2, 5-dimethyl-2, 5-bis (t-butylperoxy) hexane, 2, 5-dimethyl-2, 5-bis (t-butylperoxy) hexyne-3 and dicumyl peroxide, said vulcanization accelerator is at least one selected from the group consisting of triallyl isocyanurate, trimethylolpropane trimethacrylate and divinylbenzene, said reinforcing filler is at least one selected from the group consisting of calcium silicate, diatomaceous earth VM56 and calcium carbonate, said acid absorbing agent is at least one selected from the group consisting of zinc oxide, calcium oxide and magnesium oxide, and said internal mold release agent is at least one selected from the group consisting of 2# wax, WS280 and FPA-1.
  4. 4. The fluororubber according to claim 1, wherein the in-situ polymerization ionic liquid-polyurethane modifier is prepared from the following raw materials, by weight, 8-12 parts of isocyanate, 30-35 parts of polyol, 1-5 parts of ionic liquid and 1-3 parts of chain extender.
  5. 5. The fluororubber according to claim 4, wherein the isocyanate is at least one selected from the group consisting of diphenylmethane diisocyanate, toluene diisocyanate and hexamethylene diisocyanate, the polyol is at least one selected from the group consisting of polycarbonate diol, polytetrahydrofuran diol and polycaprolactone diol, the ionic liquid is a functionalized ionic liquid containing active hydroxyl groups or amino groups, and the chain extender is at least one selected from the group consisting of ethylene glycol, 1, 4-butanediol and diethanolamine.
  6. 6. The fluororubber according to claim 5, wherein the functional ionic liquid containing active hydroxyl is at least one selected from 1-hydroxyethyl-3-methylimidazole bistrifluoro methanesulfonimide salt, 1-hydroxyethyl-3-methylimidazole tetrafluoroborate, 1-hydroxyethyl-3-methylimidazole chloride salt, 1-hydroxyethyl-3-methylimidazole hexafluorophosphate and 1-hydroxypropyl-3-methylimidazole tetrafluoroborate, the functional ionic liquid containing active amino is at least one selected from 1-aminopropyl-3-methylimidazole hexafluorophosphate, 1-aminopropyl-3-methylimidazole tetrafluoroborate, 1-aminopropyl-3-methylimidazole bistrifluoro methanesulfonimide salt and 1-aminoethyl-3-methylimidazole tetrafluoroborate, and the number average molecular weight of the polyol is 1000-3000.
  7. 7. The fluororubber according to any one of claims 4 to 6, wherein the in-situ polymerized ionic liquid-polyurethane modifier is prepared by the steps of (1) dehydrating a polyol, adding isocyanate and a catalyst to react to obtain a mixed system, and (2) adding a chain extender, an ionic liquid and an organic solvent to react, and drying after the reaction is finished to obtain the in-situ polymerized ionic liquid-polyurethane modifier.
  8. 8. The fluororubber according to claim 7, wherein the weight portion of the catalyst is 0.01-0.1 portion, the weight portion of the organic solvent is 40-60 portions, the catalyst is at least one of dibutyl tin dilaurate and triethylene diamine, and the organic solvent is at least one of N, N-dimethylformamide, tetrahydrofuran and ethyl acetate.
  9. 9. The method for preparing the fluororubber according to any one of claims 1 to 8 is characterized by comprising the steps of (1) mixing raw fluororubber, adding an in-situ polymerization ionic liquid-polyurethane modifier, mixing uniformly, adding a reinforcing filler and an acid absorber, mixing uniformly, adding a vulcanizing agent, a vulcanization accelerator and an internal mold release agent, mixing, carrying out open mixing, sheet forming, standing, and carrying out secondary remixing to obtain a mixed rubber, and (2) vulcanizing, namely molding the mixed rubber in a mold, and then carrying out secondary vulcanization to obtain the fluororubber.
  10. 10. Use of the fluororubber according to any one of claims 1-8 for the preparation of electrically conductive seals, electrostatic protection components, electromagnetic shielding elements and flexible sensors.

Description

Conductive fluororubber modified based on in-situ polymerization ionic liquid-polyurethane and preparation method and application thereof Technical Field The invention belongs to the field of chemical materials, and particularly relates to an in-situ polymerization ionic liquid-polyurethane modified conductive fluororubber, a preparation method and application thereof. Background Fluororubber (FKM) is used as a special synthetic rubber, has excellent high temperature resistance, oil resistance, solvent resistance, acid and alkali corrosion resistance and weather resistance, and has irreplaceable application in the extreme environment fields of aerospace, automobile manufacturing, electronic and electric, petrochemical industry and the like. With the rapid development of strategic emerging industries such as high-end manufacturing, new energy automobiles, semiconductors, flexible electronics and the like, the demand for functional materials is continuously rising, the conductive modification of fluororubber has become a key direction for expanding the application field of fluororubber, and particularly in functional devices such as conductive sealing, electrostatic protection, electromagnetic shielding, flexible sensors and the like, the demand for conductive fluororubber is increasingly urgent, and the requirements for weather resistance and medium resistance in extreme environments are met, and stable conductive performance and good mechanical suitability are also required. However, due to the structural characteristics of fluororubber and the limitations of the prior modification technology, the conductive modification of fluororubber still has a plurality of short plates with key performances, and is difficult to meet the severe use requirements of high-end functional devices, and the fluororubber has the following specific steps that firstly, the highly symmetrical distribution of fluorine atoms in fluororubber molecular chains enables the fluororubber molecular chains to have strong nonpolar characteristics as a whole, the intermolecular forces are weak, and conductive active sites are lacking, so that the volume resistivity of the fluororubber is extremely high, and the fluororubber has no conductivity naturally; secondly, the prior art mainly adopts a mode of adding conductive fillers (such as carbon black, carbon nano tubes, metal particles, graphene nano tubes and the like) for modification, but the conductive fillers are required to reach a certain filling amount to form a continuous conductive network so as to meet the required conductive performance, and the addition of a large amount of conductive fillers can obviously destroy the inherent mechanical properties of fluororubber such as elasticity, toughness, tensile strength and the like, so that the problems of stress concentration, embrittlement and the like of the material occur, meanwhile, the processing difficulty of mixing, sheet discharging and the like is greatly increased, the production cost is increased, and the deformation requirement of flexible devices is difficult to adapt, thirdly, the polarity difference between the conductive fillers (especially carbon series and metal series fillers) and a fluororubber matrix is larger, the interface compatibility is poorer, the agglomeration phenomenon is easy to occur in the mixing and subsequent use processes, the conductive properties are uneven, the stability is insufficient, long-term stable conduction cannot be realized, the continuity of the fluororubber matrix is further deteriorated, the oil resistance, the solvent resistance, the high-temperature aging resistance and the like of the material are further deteriorated, the service life of the device is shortened, the ionic liquid has excellent conductivity, the thermal stability and the characteristic of being used for constructing the stable conductive network in the expected conductive network, in order to improve the conductivity, but the interface compatibility of the ionic liquid and the fluororubber matrix is poor, the problems of migration and leakage are easy to occur when the ionic liquid is directly added, a uniform and stable conductive network is difficult to form, and the cooperative improvement of the conductive performance and the mechanical performance cannot be realized. In summary, the research in the prior art focuses on a single path for modification of a single conductive filler or physical addition of an ionic liquid, and although the conductivity of fluororubber can be improved to a certain extent, the cooperative balance bottleneck of conductivity and mechanical property cannot be broken through, and the use requirements of high-end functional devices in the fields of aerospace, new energy automobiles, semiconductors, flexible wear and the like cannot be met. Therefore, development of the fluororubber conductive modification technology capable of realizing cooperative improvement of the fluororubber conductive