Method of preparing fluorine-containing copolymer for ion- exchange membranes synthesis

专利摘要:
NEW MATERIAL:Fluorinated copolymers having a repeating unit of formula I (wherein A1, A2 are F, H; A3 is F, Cl, H; A4 is F, Cl, CF3, -ORF, H, CH3; RF is 1-5C perfluoroalkyl) and a repeating unit of formula II (wherein K is 0,1; l is 3-5; Z is =S, =SO2; Y is 1-10C alkyl, aryl, Cl, 1-10C perfluoroalkyl) in a ratio of the repeating unit of formula I to the repeating unit of formula II of 1-16. USE:Raw material for fluorinated cation-exchange membrane. (There is obtd. inexpensive exchange membrane which has a long life and exhibits high current efficiency and low electric resistance under severe working conditions). PREPARATION:An olefin of formula III is copolymerized with a fluorinates sulfur- contg. vinyl ether of formula IV in the presence of a free radical polymn. initiator in a solvent.
公开号:SU1729295A3
申请号:SU864027511
申请日:1986-05-26
公开日:1992-04-23
发明作者:Кимото Киойи；Мияучи Хиротсуги；Охмура Якичи；Ебисава Микио；Хане Точиоки
申请人:Асахи Касеи Когио Кабусики Кайся (Фирма)；
IPC主号:

专利说明:

The invention relates to the synthesis of polymers for fluorinated ion-exchange membranes containing carboxyl and sulfonic acid groups.
The purpose of the invention is to increase the lifetime of the membranes while maintaining the electrochemical properties.
Example. A 300 ml stainless steel autoclave is charged with 10 g of CF2 CFO (CF2) 2SC2Hs, 0.1 g of ammonium persulfate and water. The mixture is emulsified with ammonium perfluorooctanoate (emulsifier) and polymerized at a pressure of 15 kg / sg of tetrafluoroethylene, adding sodium bisulfite as a co-catalyst, and a copolymer is obtained which, according to elemental analysis, contains 4.23% sulfur.
This copolymer is molded in the form of a film with a thickness of 250 / l and treated with gaseous chlorine at 120 ° C for 20 h, and then treated with saturated chlorine
water at 83 ° C for 20 hours. After hydrolysis of a portion of the above film with an alkali, an ion exchange capacity of 1.3 meq / g is measured, which indicates that the ratio of repeating units, i.e.
CF2-CF2: CF2-GF
0-№) zOZN
equals 4.4.
The surface of one of the sides of this film, containing sulfonyl chloride groups, is treated with a mixture containing 57% hydroiodic acid and glacial acetic acid. At a volume ratio of 15: 1, at 72 ° C, 18 h and then hydrolyzed with alkali. Further, this treated membrane is treated with a 5% aqueous solution of sodium hypochlorite at 90 ° C for 16 hours to obtain a cation-exchange membrane.
VI th o

with
Found that the density of carboxyl groups in the membrane is 100% on the surface, 88% at a depth of Sju from the surface, 68% at a depth of 10 / g, 46% at a depth of 15, 26% at a depth of 20 / g and 0% at a depth of 29 / g Conducting electrolysis deposited by the membrane assessed as follows, ..
An electrolysis cell consisting of the anodic and cathodic chambers separated by the indicated membrane with a current passage area of 0.06 dm (2x3 cm) is used, and this membrane is located in the cell so that the surface containing carboxyl groups faces the cathode. the anode uses a metal electrode with a constant size, and an iron plate as the cathode. A saturated aqueous solution of sodium chloride is introduced into the anode chamber and the anolyte pH is maintained at 3 by adding hydrochloric acid. At the same time, a 10 N aqueous solution of sodium hydroxide is circulated in the cathode chamber, to which water is added to maintain a constant concentration.
When maintained in both the anode and cathode chambers, the temperature is 95 ° C, a current is passed at a current density of 110 M / dm. The current efficiency is calculated by dividing the amount of sodium hydroxide formed in the cathode chamber by the theoretical amount calculated for the amount of current missed,
The following data was obtained during the measurement of current efficiency and cell voltage: Current passing time, h 24 720 Current efficiency,% 93 93
Voltage, V4.7 4.7
Examination of the membrane after passing a current did not reveal any physical damage, such as water bubbles, cracks or peeling.
PRI me R 2 (comparative), In a 300 ml stainless steel autoclave
CF3
load 10 g of CF, CFOCF2CFOCF2, 5 ° 2p ° 1 g
ammonium persulfate and water. The mixture was emulsified using perfluorooctano ammonium as an emulsifier, and polymerized at 50 ° C under a tetrafluoroethylene pressure of 3 kg / cm, with the addition of sodium hyposulfite as a cocatalyst. The ion exchange capacity of the resulting polymer, measured after hydrolysis,
equal to 1.3 meq / g. The ratio of repeating units in the polymer, i.e.
(CF2-CFz) :( CF2-CF2)
airsoft number) 2ad
equal to 3.3. SGS
After washing said polymer
water polymer is molded in the form of a film with a thickness of 250 / l, which is also hydrolyzed with alkali. The resulting membrane has too low mechanical strength for evaluation.
PrimerZ (comparative). Repeat
Example 2, except that the pressure of tetrafluoroethylene is increased to 5 kg / cm2, as it was found, the resulting copolymer has an ion-exchange capacity,
equal to 0.89 meq / g of dry resin. This polymer has a ratio of repeating units, namely
(CF2-CFiV. (CFiCP)
- OSGGSRO SRg) 303N
equal to 6.8.
k
After washing the specified polymer with water, it is formed into a film having a thickness of 250 / a and then hydrolyzed with alkali. The film is thoroughly dried.
EXAMPLE 4 Polymerization was carried out as in Example 1, except that CF2 CFO (CP2) C SC2H5 and CF2 CFOCF2
35
9F ° №), s2n5
load in a molar ratio of 4: 1. The resulting polymer is treated as in example 1. The results obtained are similar
described in example 1.
EXAMPLE 5 Polymerization is carried out as in Example 1, except that the pressure of tetrafluoroethylene is changed to 17. kg / cm. The ion exchange capacity of the portion of the resulting polymer, measured in Example 1, is 0.75 meq / g. As determined, the ratio of repeating units in this polymer, i.e.
50
(CF2CF2) :( CFCF)
0№) 3S03H
equals 10.
The specified polymer is molded in the form of a film with a thickness of 50 //. This film is referred to as film C, the polymer prepared in Example 1 is also molded into a film with a thickness of 100 / u. This film is referred to as d film. With film impose on
film d and molded into a layered membrane by pressing. Then, this membrane is coated with a d film side on a leno polytetrafluoroethylene fabric 0.15 mm thick; consisting of a weft of 400 denier multifilament yarns and a multifilament warp yarn with a denier of 200 denier x 2. To reinforce the said membrane, the fabric is immersed in a film d by heating under vacuum.
The layered membrane with the reinforcing material included is subjected to chlorine treatment as in Example 1 and a layered sulfonylchloride type membrane is obtained. This laminated membrane is treated from the side of the film C. with a mixture containing 57% hydroiodic acid and glacial acetic acid in a volume ratio of 10: 1 at 83 ° C for 20 hours. After hydrolysis with an alkali, the membrane is treated with 5% - sodium hypochlorite solution at 90 ° C for 16 h. The density of carboxyl groups on the surface is 92%. When studying the behavior of the membrane during electrolysis using 6 N alkali and placing the membrane with the C film side towards the cathode, the following results were obtained. No water bubbles, detachments or cracks were detected on the membrane subjected to current transmission.
Current passing time, h 24 720 Current efficiency,% 93 93
Voltage, V5.5 5.5
Example 6. A stainless steel autoclave with a capacity of 500 ml is loaded with 1,1,2-trichloro-1,2,2-trifluoroethane, CF2 CFO (CP2) x502CaH5 as a initiator of perfluoropropionyl peroxide, the polymerization is carried out at 45 ° C under tetrapressure - Torethylene 15 kg / cm2. According to elemental analysis, the resulting polymer contains 4.10% sulfur.
A part of this polymer is hydrolyzed with alkali containing potassium permanganate, and the ion-exchange capacity of the hydrolyzed polymer is 1.31 meq / g.
The sulfopolymer is molded into a 260 // membrane and then hydrolyzed with alkali containing potassium permanganate. Then this membrane is immersed in a mixture containing phosphorus pentachloride and phosphoric anhydride (weight ratio 1: 3) and treated at 110 ° C for 20 h.
After treatment of one side of the described sulfonyl chloride type membrane with a mixture consisting of hydroiodic acid and propionic acid (volume ratio 15: 1), at 72 ° C for 18 h
the treated membrane is subjected to hydrolysis with alkali, and then treated with aqueous 5% sodium hypochlorite solution
at 90 ° C for 16 hours. The surface density of the carboxyl groups is 100%.
Example. The copolymer obtained in example 1 is extruded into a fiber, which
crushed into granules with a grain diameter of 1 mm using a granulator.
The functional groups contained in the described resin are converted to the sulfonyl chloride groups of Example 1, and
then hydrolyzed to become sulfonic acid groups. Thereafter, the ion exchange capacity of the resin, which is equal to 1.3 meq / g of dry resin, is measured.
ExampleB In a 300 ml stainless steel autoclave, an emulsion is obtained by mixing 10 g of CFa CFO (CFabSCHa, 1.0 g of sodium hydrosulfate, 45 ml of purified water and 0.45 g of ammonium perfluorooctanoate). Then, 5 ml of aqueous 0 ml are added to the emulsion. , A solution of ammonium persulphate and a polymerization is carried out at a temperature of 40 ° C. under a pressure of 13 kg / cm2 of tetrafluoroethylene, and the pressure of tetrafluoroethylene is controlled so as to maintain a constant polymerization rate. elemental analysis, the resulting polymer contains 3.50 ma % sulfur. This polymer is formed into a film at 280 ° C with a thickness of 150 / g, which, in turn, is treated with chlorine gas at 120 ° C for 20 hours. Next, the said membrane is treated with a chlorine-saturated liquid containing
a mixture of perfluorobutyric acids and water (volume ratio 2: 1) with chlorine dissolved in it at 100 ° С for 48 h. The ion exchange capacity of the described membrane, determined after hydrolysis of a part of the membrane with alkali, is equal to 1.04 meq / g.
The ratio of repeating units in the membrane, i.e.
(CFi-CFi) :( CF2-CP;
oshda
equals 6.7.
After treatment of one side of the described sulfonyl chloride type membrane with a mixture consisting of 57% hydroiodic acid and acetic acid in a ratio of 30: 1 (by volume) at 72 ° C for 16 hours, it is hydrolyzed with alkali and then treated with an aqueous 5 % solution of hypochlorite.
The electrolysis is carried out under the conditions of Example 1, with the side of the membrane containing the carboxyl groups facing the catalytic results obtained are presented in Table 1 (when measuring the density of carboxyl acid groups and the maximum density gradient).
Example 9. In a 300 ml stainless steel autoclave, an emulsion is obtained by mixing 10 g of CF2 CFO (CP2) WZS2Nb, 0.1 g of ammonium persulphate and water, using ammonium perfluoroate of ammonium as an emulsifier. Tetrafluoroethylene is introduced into the autoclave under a pressure of 15 kg / cm2 and polymerization is carried out at 50 ° C with the addition of sodium hyposulfite as a cocatalyst.
According to elemental analysis, the resulting polymer contains 4.23 wt.% Sulfur. This polymer is formed into a membrane with a thickness of 250/4, which, in turn, is treated with chlorine gas at 120 ° C for 20 hours and then with a saturated aqueous solution of chlorine at 83 ° C for 20 hours. The ion exchange capacity of the membrane described above, determined after alkaline hydrolysis, is equal to 1.3 meq / g, which corresponds to the ratio of repeating units, i.e.
(CF2-CF2) :( CF-CF)
-. . .h |
equal to 4.4.) 3 §OzN
The behavior of the described memorials during electrolysis is measured by the following method.
An electrolytic cell is used consisting of the anode and cathode chambers separated by the indicated membrane with a current passage area of 0.06 dm2 (2x3 cm). A constant-sized electrode is used as an anode, and an iron plate is used as a cathode. A saturated aqueous solution of sodium chloride with a pH adjusted to 3 with hydrochloric acid is fed into the anode chamber. At this time, a 13 N aqueous solution of sodium hydroxide is circulated in the cathode chamber, to which water is added to maintain a constant concentration.
Both in the anode and in the cathode chamber, the temperature is maintained at 110 ° C and a current is passed with a current density of 120 A / dm. The current efficiency, calculated by dividing the amount of sodium hydroxide formed in the cathode chamber, by the theoretical amount, calculated from the amount of current passed, is 65%. After passing the current for 700 hours, no membrane examination is detected.
no physical damage, such as blistering, flaking or cracking.
An example. An emulsion is obtained
loading a 300 ml stainless steel autoclave with a capacity of 300 ml of 10 g of CFa CFO (СР2) ЗЗСНз, 1.0 g of sodium hydrogen phosphate, 45 ml of purified water and 0.45 g of ammonium perfluorooctanoate. Thereafter, 5 ml of aqueous solution is added to the mixture.
0 0.62% solution of ammonium persulphonate, nor, after which the polymerization is carried out
under pressure of tetrafluoroethylene 13 kg / cm2
while maintaining a temperature of
40 ° C. During the polymerization, the pressure of tet5 rafluoroethylene is controlled so as to maintain a constant polymerization rate. According to elemental analysis, the resulting polymer contains 3.5 wt.% Sulfur. This polymer is molded
0 by pressing at 280 ° C in a thin film.
The membrane thickness is 150 and obtained by molding said polymer is treated with chlorine gas at 120QC for 20 hours. Then, this membrane is treated with a chlorine-saturated liquid consisting of a mixture of perfluorobutyric acid and water (volume ratio 2: 1) with dissolved in with chlorine at 100 ° C for 48 h. The ion exchange capacity of the described membrane, determined after hydrolysis of this membrane with an alkali, is 1.04 meq / g, which corresponds to the ratio of repeating units in the membrane, i.e.
35
 lCFrGFz) :( CF2-GF)
equal to 6.7.
0 (SVDOZN
PRI me R 11. In the steel autoclave
with a capacity of 300 cm3, 10 g of CF2 CFO (CP2) z5C2H5, 0.1 g of ammonium persulphate and water are loaded, the mixture is emulsified using ammonium perfluoroctanoate as an emulsifier, and polymerization is carried out at 50 ° C and
tetrafluoroethylene pressure of 15 kg / cmr by adding sodium hydrosulfite as a cocatalyst, resulting in a copolymer. According to the elemental analysis, the sulfur content in this copolymer is 4, 23%.
A 250 μm thick film is formed from this copolymer, which is first treated with chlorine gas for 20 hours at 120 ° С and then at 83 ° С for 20 hours
saturated with chlorine water. The ion exchange capacity measured after hydrolysis of a part of the film with an alkali is equal to 1.3 meq / g, which indicates that the ratio of the groups (CF2-CFz) :( CF2CF)
0- (CF2) 3SOjH
equals 4.4.
One side of this film with sulfonyl chloride groups is treated with a mixture of 57% hydroiodic acid and glacial acetic acid (taken in a 15: 1 volume ratio) for 18 hours at 72 ° C, and then hydrolyzed with alkali. The membrane thus treated is then incubated for 16 hours at 90 ° C in a 5% aqueous solution of sodium hypochlorite, as a result of which a cation-exchange membrane is obtained.
A membrane is prepared with the same ion exchange capacity in which all ion exchange groups are converted to carboxylic acid groups.
Density of carbonic acid groups c. the membrane layers are 100% over the surface, 88% at a depth of 5 µm from the surface, 68% at a depth of 10 µm, 46% at a depth of 15 µm, 26% at a depth of 20 µm and 0% at a depth of 29 µm.
The electrochemical characteristics of the membrane are determined as follows.
For measurements, electrochemicals are used. A memorial cell, the anode and cathode spaces of which are separated by the indicated membrane with a surface for passing a current of 0.06 dm2 (2 cm x 3 cm). The membrane is mounted in a cell so that its surface with carboxyl groups faces the cathode. As an anode, an electrode made of a material with low wear is used, and an iron plate is used as a cathode. A saturated aqueous solution of sodium chloride is poured into the anode space and the pH of the anolyte is maintained at 3 by the addition of hydrochloric acid. In the cathode space, 10 n aqueous sodium hydroxide solution is circulated. Water is added to maintain the concentration.
The temperature in the anode and cathode spaces support equal to 95 ° C. The current density passing through the cell is 110 A / dm2. The current output is calculated by dividing the amount of caustic soda formed in the cathode space by its theoretical amount calculated from the magnitude of the passing current.
At certain time intervals, the current output is determined and the voltage on the cell is measured.
The following results were obtained:
Time of current passing, h 24 720 Output to flow,% 93 93
Voltage, V4.7 4.7
After current has passed, the membrane is inspected for mechanical damage, such as the inclusion of water bubbles, cracks and peeling.
Comparison of resistance against alkali proposed and known membranes are given in table 2.
When 110 A / dm2 current passes through the membrane at 95 ° C, the concentration of NaOH 10 N in a saturated aqueous solution of NaCI, the current efficiency and voltage on the cell remain constant.

权利要求:
Claims (1)
[1]
The method of obtaining a fluorine-containing copolymer for the synthesis of ion-exchange membranes by copolymerization of tetrafluoroethylene and fluorovinyl ether, contains. burning groups transformed into ionic, characterized in that, in order to increase the lifetime of the membranes while maintaining the electrochemical properties, monomer of the general formula is used as fluorovinyl ether
(СРгСРО) to (СР2) Mr. -E
CFi
where k is 0 or 1;
I 3;
Z is S or S02;
R is CH3 or C2Hs,
and copolymerization is carried out at a temperature of 40-50 ° C and a tetrafluoroethylene pressure of 13-17 kg / cm2.
Table 1
Table 2

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引用文献:

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US4474700A|1981-07-02|1984-10-02|E. I. Du Pont DeNemours and Company|β-Substituted polyfluoropropionate salts and derivatives|

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JPH0521908B2|1981-07-02|1993-03-25|Ii Ai Deyuhon De Nimoasu Ando Co|

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US6365693B1|1999-05-07|2002-04-02|Dupont Dow Elastomers, L.L.C.|Fluoroalkanesulfonyl azide copolymers|

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RU2348649C1|2007-12-20|2009-03-10|Институт катализа имени Г.К. Борескова Сибирского отделения Российской академии наук |Method of obtaining perfluorated copolymer containing functional groups|

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RU2454431C1|2011-02-07|2012-06-27|Учреждение Российской академии наук Институт катализа им. Г.К. Борескова Сибирского отделения РАН|Method of producing perfluorinated functionalised copolymer via emulsion copolymerisation|

法律状态:

优先权:

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申请号 | 申请日 | 专利标题

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JP54067889A|JPS6134725B2|1979-05-31|1979-05-31|

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