Peroxide vulcanized fluororubber and preparation method thereof

A vulcanized fluororubber and peroxide technology, which is applied in the field of fluororubber synthesis, can solve the problems of large compression set value, high pressure change limit application, unfavorable industrial production, etc., achieve low compression deformation, solve high compression deformation, The effect of shortening the dwell time

Inactive Publication Date: 2021-10-01
ZHONGHAO CHENGUANG RES INST OF CHEMICALINDUSTRY CO LTD
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

Therefore, peroxide vulcanized fluororubber products have excellent heat aging resistance, methanol resistance, fuel resistance, ozone resistance and other properties, but their high pressure change limits their application
[0003] Patent document CN108017746A discloses a preparation method of peroxide vulcanized fluororubber with low compression set, but the vulcanization points of the peroxide vulcanized fluororubber are distributed unevenly in the chain segment, resulting in long or short vulcanization time during processing. Sulfur phenomenon, especially unfavorable for industrial production
[0004] The patent document CN1989202A discloses a peroxide vulcanizable fluoroelastomer composition, which mainly greatly modifies the fluidity of the fluoroelastomer composition which has disadvantages in terms of productivity, and improves the processability, but the resulting The number-average molecular weight of fluoroelastomer is only 30,000-70,000, the cross-linking density is not enough, and the vulcanization time is too long, resulting in a large compression set value

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  • Peroxide vulcanized fluororubber and preparation method thereof
  • Peroxide vulcanized fluororubber and preparation method thereof

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Embodiment 1

[0033] The present embodiment provides a kind of peroxide vulcanized fluororubber, and its preparation method comprises the following steps:

[0034] (1) Carry out the emulsion polymerization of the present invention in a 50L reactor. Add 30L of deionized water to the reaction kettle. The reactor should be evacuated, and when the oxygen content is ≤30ppm, add 35g of ammonium perfluorooctanoate and 60g of bromotrifluoroethylene, and heat the contents of the reactor to 95°C. Raise the pressure of the reactor to 2.0 MPa with the initial mixed monomers of vinylidene fluoride, tetrafluoroethylene and hexafluoropropylene at a ratio of 40:25:35 (molar ratio). Add 15g potassium persulfate and 30g diiodomethane to start reaction;

[0035] (2) After the polymerization reaction is carried out, the potassium persulfate solution with a mass concentration of 3.18% is continuously added, and the rate of addition is 50g / 10min; the absolute pressure in the reactor is maintained at 2.0±0.3MPa...

Embodiment 2

[0040] The present embodiment provides a kind of peroxide vulcanized fluororubber, and its preparation method comprises the following steps:

[0041](1) Carry out the emulsion polymerization of the present invention in a 50L reactor. Add 30L of deionized water to the reaction kettle. The reactor should be evacuated, and when the oxygen content is ≤30ppm, add 32g of sodium perfluorooctanoate and 55g of trifluoroiodoethylene, and heat the contents of the reactor to 85°C. The initial mixed monomer vinylidene fluoride, tetrafluoroethylene and hexafluoropropylene ratio is 43:22:35 (molar ratio) to raise the pressure of the reactor to 2.5MPa. Add 12g potassium persulfate and 28g 1,4-diiodobutane to start the reaction;

[0042] (2) After the polymerization reaction was carried out, the continuous addition of mass concentration was 3.5% potassium persulfate, and the addition rate was 55g / 10min; the absolute pressure in the reactor was maintained at 2.5 ± 0.3MPa by adding the mixed m...

Embodiment 3

[0047] The present embodiment provides a kind of peroxide vulcanized fluororubber, and its preparation method comprises the following steps:

[0048] (1) Carry out the emulsion polymerization of the present invention in a 50L reactor. Add 30L of deionized water to the reaction kettle. The reactor should be evacuated, and when the oxygen content is less than or equal to 30ppm, add 35g of ammonium perfluorooctanoate and 62g of 3,3,4,4-tetrafluoro-4-bromobut-1-ene, and heat the contents of the reactor to 90°C. Raise the pressure of the reactor to 2.7 MPa with the initial mixed monomers vinylidene fluoride, tetrafluoroethylene and hexafluoropropylene at a ratio of 50:20:30 (molar ratio). Add 15g potassium persulfate and 50g 1,4-diiodoperfluorobutane to start the reaction;

[0049] (2) After the polymerization reaction is carried out, the potassium persulfate solution with a mass concentration of 3.8% is continuously added, and the feeding rate is 60g / 10min; the absolute pressur...

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Abstract

The invention relates to the field of fluororubber synthesis, and especially relates to peroxide vulcanized fluororubber and a preparation method thereof. The preparation method of the peroxide vulcanized fluororubber comprises the following step: carrying out polymerization reaction by taking vinylidene fluoride, tetrafluoroethylene and hexafluoropropylene as mixed monomers, wherein in the polymerization reaction process, the mole number of tetrafluoroethylene in a reaction kettle is always kept to be 15-25% of the total mole number of the mixed monomers, and the mole numbe of hexafluoropropylene in the reaction kettle is always kept to be 25-35% of the total mole numbe of the mixed monomers. The obtained peroxide vulcanized fluororubber has high fluorine content and low compression deformation at the same time; the problem that the cross-linking density of peroxide vulcanized fluororubber with high fluorine content is reduced in the vulcanization processing process due to non-uniform distribution of TFE and HFP in a molecular chain segment in the polymerization process is effectively solved; and meanwhile, the reaction time is controlled to be shorter, so that the branching reaction is prevented, the effectiveness of a monomer at a vulcanization point in a chain link is ensured, and the problem of higher compression deformation is solved.

Description

technical field [0001] The invention relates to the field of fluororubber synthesis, in particular to a peroxide vulcanized fluororubber and a preparation method thereof. Background technique [0002] Peroxide (or free radical) vulcanized fluororubber, obtained by copolymerization of vinylidene fluoride (VDF), tetrafluoroethylene (TFE), hexafluoropropylene (HFP) and curing point monomer (CSM), with a fluorine mass fraction of 64 % to 71%, this type of rubber not only has the unique high temperature resistance, corrosion resistance and other excellent properties of fluororubber, but also has outstanding hot tear resistance, superheated steam resistance, organic medium resistance and other properties. Therefore, peroxide vulcanized fluororubber products have excellent properties such as heat aging resistance, methanol resistance, fuel resistance, and ozone resistance, but their high pressure change limits their applications. [0003] Patent document CN108017746A discloses a p...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C08F214/22C08F214/26C08F214/28C08F214/18C08L27/16C08K13/02C08K5/14
CPCC08F214/22C08K13/02C08K5/14C08F214/26C08F214/28C08F214/182
Inventor 余金龙刘波钟子强张廷健肖忠良王先荣
Owner ZHONGHAO CHENGUANG RES INST OF CHEMICALINDUSTRY CO LTD
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