Perfluorination method for end group of fluorine-containing polymer

A fluoropolymer and perfluorinated technology, which is applied in the field of perfluorinated terminal groups of fluoropolymers, and can solve the problems of inability to apply terminal groups

Active Publication Date: 2013-06-26
ZHEJIANG XINGTENG CHEM
View PDF12 Cites 4 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

The fluorine gas used in this method is extremely active, not only can completely fluorinate the end group into -CF 3 , also replaces H in the polymer molecular chain with F, so this method cannot be used to treat end groups in specific polymers (such as VDF / HFP / TFE fluoroelastomers)

Method used

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
View more

Image

Smart Image Click on the blue labels to locate them in the text.
Viewing Examples
Smart Image
  • Perfluorination method for end group of fluorine-containing polymer
  • Perfluorination method for end group of fluorine-containing polymer

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0028] Add 900 units of water and 1 unit of ammonium perfluorooctanoate into a horizontal reactor with a volume of 1400 units of stirring (the material is new No. 3 steel), and add HFP / TFE blend monomer after evacuation treatment. The temperature is 80 / 20. When the temperature rises to 95°C, the pressure in the reactor rises to 3.5 MPa and 2.5 parts of ammonium persulfate solution is quickly added to the system, and the concentration of ammonium persulfate solution is 2.5%.

[0029] Stirring was continued during the reaction, and TFE monomer was supplemented to ensure that the reaction pressure was at 3.5 MPa. At the same time, ammonium persulfate was added at a rate of 0.2 parts / min. After continuing the reaction for 2 hours, the stirring was stopped, and the remaining monomers in the reactor were recovered. Take 1500ml of the resulting product dispersion, add 5ml of 0.3% nitric acid solution, and coagulate under the condition of 12000 rpm to obtain a white powder in the uppe...

Embodiment 2

[0033]Take the FEP powder obtained by polymerization in Example 1, press it into tablets at 250°C, place it in a 500ml stainless steel tank, and at the same time evacuate the tank, inhale 100g of the prepared end group stabilizer, and treat it at the corresponding temperature After some time, drain the stabilizer, wash the flake FEP with 0.5% NaOH alkali and dry it, then dry it after wiping it with acetone, measure the thickness of the flake, and detect it with a Fourier transform infrared spectrometer. The obtained results are shown in Table 1:

[0034]

[0035]

Embodiment 3

[0037] Add 900 units of water and 1 unit of ammonium perfluorooctanoate to a horizontal reactor with a volume of 1400 units of stirring (the material is new No. 3 steel), and add HFP / VDF blend monomer after evacuation treatment. 80 / 20, when the temperature rises to 75°C, the pressure in the reactor rises to 1.0MPa, quickly add 3.0 parts of ammonium persulfate solution to the system, the concentration of ammonium persulfate solution is 2.5%, react for 1.5 hours, during which additional blending unit body to ensure that the pressure is maintained at not less than 1.0Mpa.

[0038] Take 1500ml of the resulting product dispersion, add 5ml of 3% magnesium chloride solution, and coagulate under the condition of 12000 rpm to obtain a white powder. Wash the white powder several times in an ion-free aqueous solution, and then dry it in an oven at 120°C for 24 hours to obtain a white flaky fluororubber. The Mooney viscosity ML is tested. 1+10 121℃ for 55.

[0039] The fluorine rubber ...

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to view more

PUM

PropertyMeasurementUnit
Melt indexaaaaaaaaaa
Login to view more

Abstract

The invention discloses a perfluorination method for end group of fluorine-containing polymer. The method comprises the following steps of: mixing the fluorine polymer with an end group stabilizing reagent, standing or stirring to convert a -COF group and a -COOH group in the polymer into a -CF3 group, wherein the end group stabilizing reagent comprises the following three components: (1) SF3Ra; (2) anhydrous hydrofluoric acid AHF; and (3) one or mixture of more than any two of diethylene glycol dimethyl ether, pyridine, methylene dichloride and trichlorofluoromethane, and the reaction temperature of the perfluorination method for the end group ranges from 0 DEG C TO 100 DEG C. In the method, only specific group in the fluorine polymer is selected to be converted into -CF3, rather than that -CH2- in a polymer molecule chain with the fluoride gas fluorination process is fluorinated into -CF2-.

Description

technical field [0001] The invention relates to a method for fluorinating unstable terminal groups -COF and -COOH in fluoropolymers into stable terminal groups -CF 3 Methods. Background technique [0002] Fluoropolymers FEP, PFA, PDD, and PVDF, VDF / HFP / TFE copolymers have excellent weather resistance and dielectric properties and are widely used in various industries. The aqueous phase dispersion polymerization process has the characteristics of strong reaction controllability, high product uniformity, and mild reaction conditions, so this process is widely used in the polymerization of the above products. [0003] In view of the introduction of the polymerization initiator inorganic peroxide, the terminal group of the polymer forms a structure of -COF, -COOH, and this type of structure is unstable under high temperature conditions (>250°C). If such unstable terminal groups are not stabilized, it will not only affect the performance of fluoropolymer products, but also c...

Claims

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to view more

Application Information

Patent Timeline
no application Login to view more
IPC IPC(8): C08F14/18C08F14/22C08F14/26C08F16/24C08F8/20
Inventor 赵景平陈文亮鲁红玉洪海江
Owner ZHEJIANG XINGTENG CHEM
Who we serve
  • R&D Engineer
  • R&D Manager
  • IP Professional
Why Eureka
  • Industry Leading Data Capabilities
  • Powerful AI technology
  • Patent DNA Extraction
Social media
Try Eureka
PatSnap group products