RU2230075C1 - Method of producing perfluorinated copolymers with sulfonylfluoride functions - Google Patents

Abstract

FIELD: polymer production. SUBSTANCE: invention relates to production of perfluorinated copolymers with sulfonylfluoride functions via copolymerization of tetrafluoroethylene with perfluorocarbon vinyl ether of formula CF₂=CF-O-CF₂-CF(CF₃)-O-CF₂-CF₂-SO₂F, in fluorine-containing organic solvent or in bulk influenced by radical-type perfluorinated peroxide at elevated pressure, wherein reaction mixture is continuously fed by additional tetrafluoroethylene. Before copolymerization is started, preliminarily prepared hydrolyzed tetrafluoroethylene polymer with 9.5-15 mol % of above-indicated perfluorocarbon vinyl ether is added to reaction mixture in amount 0.3-0.66% on the weight of liquid reaction mixture in the form of dispersion in fluorine-containing organic solvent. Above-mentioned peroxide is selected from bis-perfluoro(2-oxa-p-methyl-dioxane-propionyl)peroxide, bis-perfluoro(2,5,8-trimethyl-3,6,9-trioxa-dodecanoyl)peroxide, bis-perfluoro(cyclohexanoyl)peroxide, and mixtures thereof. Process is carried out at 20-35(r) and pressure 0.25-0.6 MPa to yield copolymer containing 3.5 to 19 mol % of above-indicted perfluorocarbon vinyl ether. EFFECT: improved heat resistance and ability to be extruded into products less than 100 mcm in thickness and to form, after hydrolysis, concentrated solutions suitable for manufacturing thin films, by flooding technique, and hollow fibers with wall thickness 30-80 mcm. 7 cl, 2 tbl, 26 ex

Description

The invention relates to a technology for producing perfluorinated copolymers with functional sulfonyl fluoride groups, in particular, copolymers of tetrafluoroethylene with perfluorinated vinyl sulfonated esters, i.e. copolymers containing functional groups in their structure capable of being converted into ion-exchange groups. Such copolymers are used in the manufacture of cation exchange fluorocarbon membranes (KOM) used in fuel cells, in the electrolysis of water, aqueous solutions of alkali metal salts, for example in chlor-alkali electrolysis, in the preparation of liquid ion-exchange polymer compositions (solutions).

Perfluorinated copolymers with sulfonyl fluoride functional groups can be obtained by radical copolymerization of tetrafluoroethylene (TFE) and perfluorocarbon vinyl ether containing a sulfonyl fluoride group (-SO ₂ F) in an aqueous or organic medium or in bulk fluorocarbon sulfonyl fluoride copolymers of the resulting vinyls are determined by the ratio of monomers used and synthesis conditions.

Known [US patent No. 3282875, NKI 260-29.6, publ. 11/01/16] a method for producing perfluorinated copolymers with sulfonyl fluoride functional groups by copolymerizing TFE and a fluorocarbon vinyl ether with sulfonyl fluoride group (HHFE), for example, structural formula CF ₂ = CF-O-CF ₂ -CF (CF ₃ ) -O-CF ₂ - CF ₂ -SO ₂ F, in the environment of a fluorocarbon solvent - perfluorodimethylcyclobutane in the presence of a radical initiator, preferably difluorodiazine (N ₂ F ₂ ) at a temperature of 80 ° C and autogenous pressure. Receive perfluorinated copolymers with a content of 0.2-5 wt.% VSGE. Such copolymers can be used to obtain crosslinkable chemically resistant and thermostable coatings, for the manufacture of KOM and super acid catalysts.

The disadvantages of this method are:

- a relatively high copolymerization temperature (80 ° C), which contributes to the formation of a low molecular weight copolymer and increases the danger of the copolymerization process, since TFE is an explosive monomer;

- the impossibility of manufacturing durable products (films, fibers) from the resulting copolymer due to its low molecular weight (MM);

- heterogeneity in the composition of the obtained copolymer due to the lack of feed with tetrafluoroethylene during the copolymerization process and the possibility of the formation of a homopolymer (PTFE) at temperatures of about 80 ° C.

Also known [RF patent No. 2135815, IPC ⁶ C 08 F 214/26, C 08 J 5/22, publ. 09/27/99] a method for producing fluorocarbon (perfluorinated) copolymers containing functional sulfonyl fluoride groups by copolymerization in a block (in bulk) of TFE with HESE of the structural formula CF ₂ = CF-O-CF ₂ -CF (CF ₃ ) -O-CF ₂ -CF ₂ -SO ₂ F in the presence of a perfluorinated peroxide initiator, in particular perfluoropropionyl peroxide (PFPP) at a temperature of 0-20 ° C, with continuous feeding of TFE to a conversion of 12 mol.% VGE. Strong films with good physical and mechanical properties can be made from the obtained copolymers.

The disadvantages of this method are:

- low conversion of monomer - HESE (12%), which leads to low productivity of the process and high costs for the regeneration of HESE;

- the difficulty of controlling the properties of the obtained copolymer according to MM, composition, crystallinity, density, etc., because regulation of properties is possible only by changing the concentration of monomers and initiator, which is not effective enough to obtain copolymers with desired optimal properties;

- insufficient thermal stability of the resulting copolymer due to the presence in it of C ₂ F ₅ COO groups formed during the decay of the initiator - PFPP and decomposing at 220-240 ° C, i.e. at temperatures close to the melting temperature of the copolymer and its processing temperature, which affects the quality of the copolymer and the products obtained from it (see our control example No. 14).

Known [USSR patent No. 1233804, MKI C 09 F 214/26, C 08 J 5/22, publ. 05/23/86] a method for producing a perfluorinated copolymer with sulfonyl fluoride groups by copolymerizing TFE and HHPE in an aqueous emulsion medium in the presence of a water-soluble radical type polymerization initiator (preferably a redox system consisting of potassium persulfate, sodium persulfate or ammonium persulfate, sodium hyposulfite and an accelerator - copper sulfate) and the fluorinated surfactant (ammonium perfluorooctanoate) at 40 ° C. The pressure of TFE, e.g. 4-5 kg / cm ² (0.4-0.5 MPa) is controlled so that provide a constant rate of copolymerization. Esters of the structural formula CF ₂ = CF-O- (CF ₂ -CF (CF ₃ ) -O) _K - (CF ₂ ) ₃ -SO ₂ F, where K = 0 or 1, are used as HESE.

The ratio of the repeating units of TFE and said HESE in the copolymer is 6.0-8.9. The resulting copolymer is hydrolyzed to convert sulfonyl fluoride groups (—SO ₂ F) to the ion exchange form (—SO ₃ M, where M is an alkali metal). The method according to USSR patent No. 1233804 allows to obtain perfluorinated copolymers with an exchange capacity (OE), for example, 0.72-1.08 mEq / g dry resin, which corresponds to an equivalent mass (EM) of 1389-926 (EM is the mass of the hydrolyzed copolymer in g per 1 mEq of functional group). Such copolymers are suitable for producing membranes used in electrolysis processes, in particular chlor-alkali electrolysis.

The disadvantages of the method according to USSR patent No. 1233804 are:

- the presence in the resulting copolymer of impurities introduced by the emulsifier and copper sulfate used in the synthesis, as well as the presence of unstable end groups formed in the copolymer during the decomposition of the initiator — potassium, sodium or ammonium persulfate, which impairs the thermal stability and appearance of the resulting copolymer and the quality of products manufactured out of him;

- the difficulty of adjusting the properties of the obtained copolymer in composition, MM, crystallinity, density, etc., since in accordance with the described method it is possible to adjust the properties only by changing the concentration of reagents (see examples 1 and 4 of the description of the invention to USSR patent No. 1233804 ), which is not effective enough in the synthesis of copolymers with desired properties;

- the impossibility of producing thin (less than 100 μm) films from the obtained copolymer by extrusion due to its high MM (indirect characteristic MM - melt flow rate (MFR) of 0.2 g / 10 min at 275 ° C), as well as the impossibility of obtaining concentrated solutions copolymers (more than 5 wt.%) in accessible media (isopropanol, ethanol, dimethylformamide, butanol, etc.), which are used in the manufacture by irrigation of membranes with a thickness of 30-100 microns, hollow fibers (with a wall thickness of 20-100 microns) wet and other thin-walled products.

The closest set of essential features to the claimed method is the method according to USSR patent No. 721006 [MKI ² C 08 F 8/32, publ. 03.03.80], in accordance with which perfluorinated copolymers with sulfonyl fluoride functional groups are obtained by copolymerization of fluorinated ethylene, preferably TFE, and HESE in the presence of a radical type initiator, perfluorinated peroxide (PFPP) in a fluorinated organic solvent, for example 1,1,2-trichloro -1,2,2-trifluoroethane (Freon-113), perfluoromethylcyclohexane or perfluorodimethylcyclobutane, at a temperature of 45 ° C and a pressure of 3-7 kg / cm ² (0.3-0.7 MPa), which is supported by constant replenishment of the TFE reaction medium during the copolymerization process (see examples 1 and 3 of the description of the invention to USSR patent No. 721006). Esters of the structural formula CF ₂ = CF- [OCF ₂ -CF (Y)] _n -OCF ₂ CF ₂ -SO ₂ F, where Y = F or alkyl fluoride with the number of carbon atoms from 1 to 5; n = 0-3.

Most preferred is the HSE of the structural formula

CF ₂ = CF — O — CF ₂ —CF (CF ₃ ) —O — CF ₂ —CF ₂ —SO ₂ F.

, среднечисленная молекулярная масса

, отношение

, степень кристалличности и плотность, в патенте СССР №721006 не приводятся. Способ позволяет получать сополимеры, пригодные для изготовления мембран, применяемых в процессах электролиза, в частности при электролизе водных растворов галогенидов щелочных металлов, так как из сополимера получают достаточно прочные пленки (мембраны).The resulting copolymer is hydrolyzed to convert sulfonyl fluoride groups (—SO ₂ F) to the ion exchange formula (—SO ₃ M). Depending on the pressure created by TFE, copolymers of the required exchange capacity are obtained, in particular copolymers with OE of 0.68, 0.74 and 0.91 mEq / g dry copolymer are obtained. A copolymer with an OE of 0.67-1.0 mEq / g of copolymer is preferred, which corresponds to EM 1500-1000. Properties of the resulting copolymers, such as PTR, weight average molecular weight

, number average molecular weight

attitude

, the degree of crystallinity and density are not given in USSR Patent No. 721006. The method allows to obtain copolymers suitable for the manufacture of membranes used in electrolysis processes, in particular during the electrolysis of aqueous solutions of alkali metal halides, since sufficiently strong films (membranes) are obtained from the copolymer.

The disadvantages of the prototype method (USSR patent No. 721006) are:

- the impossibility of making thin (thickness less than 100 microns) products, such as films and tubes (wall thickness less than 100 microns) from the obtained copolymers by extrusion, as well as the impossibility of obtaining concentrated solutions from these copolymers (more than 5 wt.%) in accessible media ( isopropanol, ethanol, dimethylformamide, acetone, etc.), which are used for the manufacture of hollow fibers with a wall thickness of 30-80 microns by the wet method and thin films (25-80 microns) by irrigation. (This is probably due to the properties of the obtained copolymers. So, according to our data (see our control examples 15 and 16), the copolymers obtained by the prototype method contain fractions with too high MM (MFR 1.9-2.1 g / 10 min at a temperature of 270 ° C and a load of 2.16 kg) and with an EM of 1000-1500 have a too high degree of crystallinity (18-24%) and high density (2.095-2.097 g / cm ³ ), which does not allow them to be processed into the indicated products by the specified methods);

, степень кристалличности и плотность, связанная с тем, что регулирование свойств возможно только за счет изменения концентрации инициатора, ВСГЭ или давления, что недостаточно эффективно;- the difficulty of controlling the properties of the obtained copolymers, such as MM, the ratio

, the degree of crystallinity and density due to the fact that the regulation of properties is possible only by changing the concentration of the initiator, HESE or pressure, which is not effective enough;

- too high a melting point of the resulting copolymers (300-310 ° C), which when processed into products leads to partial destruction of functional groups (-SO ₂ F), which begin to decompose at a temperature of 270 ° C [Plastics, 1980, No. 12, p. 23-25], and therefore, contributes to the deterioration of the quality obtained from the copolymer products (membranes);

- insufficiently high thermal stability of the obtained copolymers, due to the presence in the copolymer of insufficiently thermally stable terminal C ₂ F ₅ COO groups introduced by the initiator - PFPP (formed during the decomposition of PFPP in the copolymerization process).

The technical result, which is achieved by the claimed method, consists in simplifying the regulation of the properties of the obtained copolymers in the synthesis process, as well as in obtaining copolymers with improved thermal stability, the ability to be processed into products with a thickness of less than 100 microns by extrusion and to form concentrated solutions after hydrolysis (at least 6 -20%), suitable for the manufacture of thin (less than 100 microns) films by irrigation and hollow fibers with a wall thickness of 30-80 microns.

The specified technical result is achieved due to the fact that in the method for producing perfluorinated copolymers with functional sulfonyl fluoride groups by copolymerization of TFE with perfluorocarbon vinyl ether having the structural formula CF ₂ = CF-O-CF ₂ -CF (CF ₃ ) -O-CF ₂ -CF ₂ -SO ₂ F, in a fluorine-containing organic solvent or in bulk under the influence of a radical type initiator - perfluorinated peroxide at elevated pressure with the reaction medium fed with tetrafluoroethylene during the copolymerization process, before starting with polymerization of the reaction medium is introduced pre-obtained hydrolyzed copolymer of TFE with 9.5-15 mol.% HESE of the above structural formula in an amount of 0.3-0.66% by weight of the liquid reaction medium, and the specified hydrolyzed copolymer is introduced into the reaction medium in the form dispersions in a fluorine-containing organic solvent, and as a perfluorinated peroxide, a peroxide selected from the group consisting of bis-perfluoro- (2-oxa-para-methyl-dioxane-propionyl) peroxide, bis-perfluoro- (2,5,8 -trimethyl-3,6,9-trioxa-dodecanoyl) - peroxide, bis-perfluoro- (cyclohexanoyl) -peroxide or mixtures thereof, and the process is carried out at a temperature of 20-35 ° C and a pressure of 0.25-0.6 MPa to obtain a copolymer containing 3.5-19 mol.% vinyl perfluorocarbon ether of the above structural formula. As a dispersion of a hydrolyzed TFE copolymer with VGE, a dispersion of the copolymer in a fluorine-containing organic solvent with a concentration of 10-20 wt.% Is used.

When using bis-perfluoro- (2-oxa-para-methyl-dioxane-propionyl) -peroxide (PFDOP) as perfluorinated peroxide, the copolymerization is carried out at a temperature of 20-25 ° C and a pressure of 0.25-0.6 MPa; when using bis-perfluoro- (2,5,8-trimethyl-3,6,9-trioxa-dodecanoyl) peroxide (PFDP), the copolymerization is carried out at a temperature of 25-30 ° C and a pressure of 0.26-0.6 MPa; when using bis-perfluoro- (cyclohexanoyl) -peroxide (PFCP), the copolymerization is carried out at a temperature of 30-35 ° C and a pressure of 0.28-0.6 MPa. It is possible to use mixtures of these peroxides, in particular PFDOP-PFDP mixtures in a mass ratio of 1: 6, respectively, while the copolymerization process is carried out at a temperature of 23-28 ° C and a pressure of 0.25-0.6 MPa, or a mixture of PFDP with PFCP in mass 1: 5 ratio, respectively, while the copolymerization process is carried out at a temperature of 28-35 ° C and a pressure of 0.27-0.6 MPa.

(см. наши примеры 1 и 3). Введение предварительно гидролизованного сополимера ТФЭ с 9,5-15 мол.% ВСГЭ позволяет синтезировать сополимеры, имеющие заданные значения

, отношения

, кристалличности и плотности, оптимальные с точки зрения как переработки их из расплава, например экструзией, так и получения из них растворов в доступных органических растворителях, в том числе получения растворов концентрацией не менее 6-20 мас.%.The authors of the present invention found that if before starting the process of copolymerization of TFE with VGE in the reaction medium, the previously obtained hydrolyzed TFE copolymer with 9.5-15 mol% of VGE in the amount of 0.3-0.66% by weight of the liquid reaction medium is introduced ( for example, in the form of a 10-20% dispersion in a fluorine-containing organic solvent), then the previously pre-hydrolyzed copolymer acts as a regulator of MM and molecular weight distribution (MMP), and also contributes to the formation of a certain structure of the forming during the synthesis of the copolymer, which allows one to influence its crystallinity and density. Under the same synthesis conditions, when a copolymer of the same composition is obtained by introducing various amounts of a pre-hydrolyzed TFE-HPSE copolymer, copolymers of the desired structure with different MM and MMP can be obtained, which is characterized by the ratio

(see our examples 1 and 3). The introduction of a pre-hydrolyzed TFE copolymer with 9.5-15 mol.% VGE allows you to synthesize copolymers having specified values

, relations

crystallinity and density, optimal from the point of view of both processing them from a melt, for example by extrusion, and obtaining solutions from them in accessible organic solvents, including obtaining solutions with a concentration of at least 6-20 wt.%.

=(2-7)· 10⁵,

=1,41-1,46, ПТР=7-100 г/10 мин (при 270° С), степень кристалличности 7-20%, плотность 2,07-2,085 г/см³, прочность при разрыве 24-33 МПа, температура плавления (Т_пл) 210-260° С, при этом сополимеры однородны по составу.According to the claimed method, depending on the purpose, copolymers with a HGE content of 3.5-19 mol%, preferably 8-15 mol%, having after hydrolysis of EM 1000-2600, preferably 1000-2000, and having the following complex of physical and physical and mechanical characteristics:

= (2-7) · 10 ⁵ ,

= 1.41-1.46, MFR = 7-100 g / 10 min (at 270 ° C), crystallinity 7-20%, density 2.07-2.085 g / cm ³ , tensile strength 24-33 MPa the melting point (T _PL ) 210-260 ° C, while the copolymers are homogeneous in composition.

As indicated above, according to the claimed method, a pre-hydrolyzed copolymer of TFE with VGE is introduced in an amount of 0.3-0.66% by weight of the liquid reaction medium (solvent and / or VGE). If a smaller amount of hydrolyzed copolymer is introduced (less than 0.3%), then it does not exhibit a regulatory effect and the resulting TFE-HPSE copolymer does not differ in properties from the copolymer obtained without its use (see our control example No. 12). The introduction of a hydrolyzed copolymer of more than 0.66% by weight of the liquid reaction medium is impractical because significantly the quality of the obtained TFE copolymer with VGE does not improve, and the consumption of hydrolyzed copolymer increases (see our control example No. 13).

To prepare a dispersion of a hydrolyzed TFE copolymer with VGE, it is advisable to use a hydrolyzed TFE copolymer with VGE with EM 920-1300 with ion-exchange groups in the form of -SO ₃ H, -SO ₃ Na, -SO ₃ K or -SO ₃ Li.

In the following examples, the following hydrolyzed copolymers of TFE with HESE were synthesized by the inventors:

SPL-1 with EM 920 and ion-exchange groups —SO ₃ H;

SPL-2 with EM 950 and ion-exchange groups —SO ₃ Na;

SPL-3 with EM 1120 and -SO ₃ Na ion-exchange groups;

SPL-4 with EM 1450 and ion-exchange groups —SO ₃ H;

SPL-5 with EM 1200 and ion-exchange groups —SO ₃ K;

SPL-6 with EM 1300 and ion-exchange groups —SO ₃ Li.

A dispersion of a hydrolyzed copolymer in a fluorine-containing organic solvent is obtained by dispersing a copolymer powder (SPL-1, SPL-2, SPL-3, SPL-4, SPL-5 or SPL-6) with a particle size of not more than 200 μm in the solvent with stirring for 2 hours at a temperature of 20-90 ° C, cooling the resulting dispersion to room temperature and filtering it through a nylon filter. Freon-113 (freon-113), perfluorocyclobutane and other fluorinated solvents can be used as a fluorine-containing organic solvent for preparing the dispersion.

In the implementation of the proposed method, the copolymerization process can be carried out both in the presence of a solvent, and in the bulk of HESE. Moreover, in the case of obtaining copolymers with an HSE content of less than 10 mol%, it is advisable to carry out the copolymerization process in the presence of a solvent, since the presence of a solvent provides the required high concentration of TFE in the reaction medium at low pressure. In the case of obtaining copolymers with an HSE content of more than 10 mol%, a high concentration of TFE in the reaction medium is not required and the copolymerization process can be carried out both in the presence of a solvent and without it, i.e. in the mass of monomer - VGE.

Perfluorocyclobutane, perfluorodimethylcyclobutane, 1,1,2-trichloro-1,2,2-trifluoroethane (freon-113), etc. can be used as a fluorine-containing solvent in the copolymerization process.

As already mentioned above, as perfluorinated peroxides, PFCP, PFDP, PFDOP or mixtures thereof can be used. The use of such peroxides allows the copolymerization process to be carried out at a fairly high speed at a low temperature (20-35 ° C), which makes it easy to control the process and promotes the formation of copolymers with a given set of properties that allows them to be processed into products with a thickness of less than 100 microns.

The use of such peroxides is described, for example, in the preparation of TFE copolymers with hexafluoropropylene (see RF patent No. 2109761, MKI ⁶ C 08 F 214/26, publ. 04/27/98) or TFE copolymers with perfluoropropyl vinyl ether (see RF patent No. 21567677, IPC ⁷ C 08 F 214/26, publ. 09/27/2000). The copolymerization temperature of TFE with HHPE is determined by the type of initiator used and is in the range of 20-35 ° C. The copolymerization pressure created and maintained by the TFE feed is set depending on the type of initiator, solvent and the given composition of the resulting copolymer and is in the range 0.25- 0.6 MPa (the higher the pressure of TFE, the greater its content in the copolymer). Before the start of the process, the calculated amounts of HESE - monomer, organofluorine solvent and perfluoroperoxide (in the form of a 10% solution in an organic solvent) are loaded into the prepared reactor (if the process is carried out in bulk, then the solvent is not charged). Then, the calculated amount of the pre-hydrolyzed TFE-HPSE copolymer in the form of a dispersion is fed into the reactor. The TFE pressure in the reaction process is supported by the continuous supply of TFE with a pressure drop of 0.02-0.03 MPa. At the end of the process, the finished TFE-HPSE copolymer is discharged from the reactor as a dispersion in a mixture of solvent and unreacted HESE (when carrying out the process in a solvent medium) or in unreacted HESE (when carrying out the process in bulk). Conversion by HSE is 16-25%. The copolymer is isolated from the dispersion by distillation of the solvent and / or unreacted HESE.

The properties of the obtained TFE-HES copolymers were determined as follows:

1. The content of HESE in the copolymer was determined by IR spectroscopy on a spectrometer company Perkin-Elmer, model 1760.

определяли расчетным путем.2. The number average and weight average molecular weights were determined by thin-layer or liquid chromatography of a 1-5% solution of the copolymer in isopropyl alcohol or dimethylacetamide. Attitude

determined by calculation.

3. The degree of crystallinity was determined by X-ray diffraction using a small-angle scattering chamber KRM-1.

4. The density was determined according to GOST 15139-69.

5. Thermostability was determined by the loss of mass of the copolymer powder when it was held at a temperature of 270 ± 5 ° C for 5 hours.

6. The equivalent mass was determined by calculation by the total exchange capacity, which was determined according to GOST 17552-72 on film samples 0.2 ± 0.05 mm thick, obtained by pressing a copolymer sample at a temperature of 220 ± 2 ° C and a pressure of 20 ± 2.5 MPa

7. The melt flow rate (MFR) was determined according to GOST 11645-73 on an extrusion plastomer of the IIRT-AM type at a temperature of 270 ± 0.5 ° C, a load of 2.16 kg, on a capillary with a diameter of 2.09 ± 0.005 mm at a sample exposure time in the extrusion chamber under load for 5 minutes

8. The tensile strength (σ p) was determined according to GOST 11262-80 on samples with a thickness of 1.5 ± 0.2 mm, made by pressing the copolymer powder at a temperature of 220-240 ° C and a pressure of 20 ± 2.5 MPa.

The following examples illustrate the present invention.

Example 1

In a 1.3 liter stainless steel reactor equipped with an anchor stirrer and a jacket, 650 g of Freon-113, 312 g of HESE of the formula CF ₂ = CF-O-CF ₂ -CF (CF ₃ ) -O-CF ₂ -CF are charged ₂ -SO ₂ F, 0.52 g of PFSP in the form of a 10% solution in HFC-113 and 3 g (0.3% by weight of the liquid reaction medium - HFC-113 and HFCE) of the previously hydrolyzed TFE-HFC copolymer SPL- 1 (EM 920, ion exchange groups SO ₃ H) as a 10% dispersion in HFC-113. The reactor is cooled to a temperature of -30 ° C, vacuum to a residual pressure of 10 mm Hg and with stirring, 30 g of TFE are introduced into it. Then the reactor is heated to a temperature of 32 ° C, while the pressure is set at 0.29 MPa, and 104 g of TFE are fed into it gradually as the pressure drops by 0.01 MPa for 12 hours. The copolymerization process is carried out at a pressure of 0.29 MPa, gradually reducing it at the end of the polymerization to 0.25 MPa. After the copolymerization process is completed, the reactor is cooled to a temperature of 15 ° C and the unreacted TFE is blown off. After that, the obtained dispersion of the TFE copolymer with HFCE in a mixture of HFC13 and unreacted HFCE is discharged from the reactor, and HFC13 and HFCE are distilled off. The resulting copolymer is washed with HFC-113 and dried under vacuum at a temperature of 80 ° C. 174 g of TFE copolymer powder with 15.3 mol% of VGE are obtained. The conversion of HESE is 24.2%.

The process parameters and properties of the copolymers of example 1 and all of the following examples are shown in tables 1 and 2, respectively.

Examples 2-11 and 12-16 (control).

The process is carried out analogously to example 1, but the process parameters vary. In examples 14, 15, 16 (counter. Prototype and analogue), the hydrolyzed TFE copolymer with HHPE is not introduced and the copolymerization process is carried out in the presence of PFPP.

In examples 9 and 14 (control), the copolymerization process is carried out in the bulk of the monomer - HHPE (i.e., in the absence of solvent), in example 10 - in PPSB medium, and in all other examples - in HFC-113 medium. In example 8, a mixture of PFDOP and PFDP in a mass ratio of 1: 6 is used as peroxide.

Example 17

=2,5· 10⁵,

=1,44. В круглодонную колбу объемом 500 мл, снабженную мешалкой, термометром и обратным холодильником, загружают 30 г порошка указанного гидролизованного сополимера ТФЭ с ВСГЭ с размером частиц 100-500 мкм и 170 г изопропилового спирта (изопропанол), включают мешалку и растворяют при температуре 70° С в течение 1 ч. Сополимер полностью растворяется при указанных условиях. Затем полученный раствор охлаждают до комнатной температуры и фильтруют через капроновый фильтр. После фильтрации раствор имеет концентрацию 15 мас.%. Полученный раствор используют для изготовления газоразделительного полого волокна. Полое волокно получают на лабораторной установке мокрым способом в осадительной ванне, содержащей 80 мас.% воды и 20 мас.% изопропанола. Внутренний диаметр волокна составил 80 мкм, толщина стенки - 40 мкм. Полученное полое волокно использовали в газоразделительном устройстве для выделения аммиака из смеси аммиака и водорода. Газовую смесь, состоящую из 50 об.% аммиака и 50 об.% водорода, подают внутрь полого волокна, предварительно увлажняя водяным паром, под давлением 100 кПа и при температуре 22° С. На основе анализа состава газовой смеси с внешней стороны волокна вычисляют коэффициент проницаемости составляющих смесь газов, которые для аммиака и водорода равны 3,82· 10^-11 и 1,99· 10^-15 моль· м/м²· с· Па соответственно, и коэффициент селективности, равный 1,92· 10⁴ в пользу аммиака. После очистки смесь содержит 99,8 об.% аммиака и 0,2 об.% водорода.A TFE copolymer with VGE with functional groups —SO ₂ F, obtained according to Example 3, with a crystallinity of 11% and a density of 2.074 g / cm ^{3 is} used to obtain a solution with a concentration of 15 wt.%. Before dissolving, the copolymer powder is hydrolyzed with a 10% aqueous solution of hydroxy lithium (LiOH) at a temperature of 95 ° C for 12 hours, after which the hydrolyzed copolymer is washed with water from lithium hydroxide and dried in a thermostat at a temperature of 95-98 ° C. After hydrolysis, the copolymer contains functional groups —SO ₃ Li and has EM = 1000,

= 2.5 · 10 ⁵ ,

= 1.44. A 500 ml round bottom flask equipped with a stirrer, thermometer and reflux condenser was charged with 30 g of the powder of the indicated hydrolyzed TFE copolymer with HESE with a particle size of 100-500 μm and 170 g of isopropyl alcohol (isopropanol), the stirrer was turned on and dissolved at a temperature of 70 ° С within 1 h. The copolymer is completely dissolved under the indicated conditions. Then, the resulting solution was cooled to room temperature and filtered through a nylon filter. After filtration, the solution has a concentration of 15 wt.%. The resulting solution is used for the manufacture of gas separation hollow fiber. Hollow fiber is obtained in a laboratory setup by the wet method in a precipitation bath containing 80 wt.% Water and 20 wt.% Isopropanol. The inner diameter of the fiber was 80 μm, the wall thickness was 40 μm. The obtained hollow fiber was used in a gas separation device for separating ammonia from a mixture of ammonia and hydrogen. The gas mixture, consisting of 50% vol. Ammonia and 50% vol. Hydrogen, is fed into the hollow fiber, pre-moistened with water vapor, at a pressure of 100 kPa and at a temperature of 22 ° C. Based on the analysis of the composition of the gas mixture from the outside of the fiber, the coefficient the permeability of the gases constituting the mixture, which for ammonia and hydrogen are 3.82 · 10 ^-11 and 1.99 · 10 ^-15 mol · m / m ² · s · Pa, respectively, and a selectivity coefficient of 1.92 · 10 ⁴ in the benefit of ammonia. After purification, the mixture contains 99.8 vol.% Ammonia and 0.2 vol.% Hydrogen.

Example 18

The solution obtained in example 17 and containing 15 wt.% Hydrolyzed copolymer with EM 1000 in isopropanol, is used to obtain a gas separation membrane in the form of a film. A membrane in the form of a film is obtained by pouring a solution of such a thickness onto the glass of the indicated solution so that after removal of the solvent a film with a thickness of 40 μm is formed. The glass with the solution poured on it is placed in a thermostat and the solvent is evaporated with a gradual increase in temperature from 22 ° C to 80 ° C for 40 minutes (at 22 ° C - 10 minutes, at 80 ° C - 30 minutes). The film is removed from the glass and used as a gas separation membrane. A gaseous feed mixture of hydrogen fluoride and 1,1,2-trichloro-trifluoroethane (80 vol.% Hydrogen fluoride and 20 vol.% 1,1,2-trichlorotrifluoroethane) is fed to a high pressure chamber. The differential pressure of hydrogen fluoride on the membrane is 50 kPa. Based on the analysis of the composition and quantity of the gas mixture in the receiving chamber, the selectivity coefficient was 1 · 10 ³ in favor of hydrogen fluoride with a plant productivity of 0.25 m ³ / m ^{2 of} gas mixture. After purification, the mixture contains 98% hydrogen fluoride and 2% 1,1,2-trichlorotrifluoroethane.

Example 19

=6· 10⁵,

=1,43 и функциональные группы -SO₃Н. Сополимер аналогично примеру 17 растворяют при температуре 70° С в этиловом спирте и получают раствор с концентрацией сополимера 15 мас.%. Полученный раствор используют при изготовлении ионообменной мембраны в форме пленки. Мембрану в форме пленки получают поливом на стекло указанного раствора слоем такой толщины, чтобы после удаления растворителя образовалась пленка толщиной 80 мкм. Стекло с налитым на него раствором помещают в термостат и испаряют растворитель при постепенном подъеме температуры с выдержкой при 22° С в течение 10 мин и при 80° С в течение 40 мин. После удаления растворителя мембрана (пленка) имела толщину 80 мкм и предел прочности при растяжении 25 МПа. Полученную пленку использовали в качестве мембраны при изготовлении мембрано-электродных блоков (МЭБ) для электролиза воды. Для получения электродного материала в стеклянной емкости смешивают 0,92 г катализатора - платиновой черни (размер частиц 0,06 мкм) с 2,2 г 6%-ного раствора, полученного растворением сополимера по примеру 8 (степень кристалличности 16,5%, плотность 2,084 г/см³,

=6,2· 10⁵,

=1,42, функциональные группы -SO₃Н, ЭМ 1400) в изопропаноле при температуре 80° С в течение 2 часов. Полученную вязкую массу наносят на одну из поверхностей полученной, как указано выше, высушенной мембраны в виде воздушно-сухой пленки диаметром 100 мм методом полива смеси такой толщины, чтобы после удаления растворителя слой электродного материала имел толщину 10 мкм. Затем пленку помещают в термостат и термообрабатывают при ступенчатом подъеме температуры: выдержка при 40° С в течение 15 мин, при 70° С - в течение 40 мин. После этого мембрану вынимают из термостата, охлаждают до комнатной температуры и аналогичным образом на другую ее поверхность наносят тот же самый электродный материал, помещают в термостат и термообрабатывают указанным выше способом. Полученный МЭБ испытывают при электролизе воды. К МЭБ с обеих сторон прижимают коллектор тока из пористого титана с токоотводами, уплотняют полученную сборку с помощью стяжки плит, погружают в сосуд с дистиллированной водой и подают электрический ток силой 0,5 А/см² при 90° С в течение 1 часа. Затем сборку устанавливают в ячейку для электролиза деионизованной воды. Напряжение на блоке составило 1,62 В при плотности тока 1 А/см² и температуре 100° С.The copolymer solution is obtained analogously to example 17, but to obtain the solution using the copolymer obtained in example 6, having a degree of crystallinity of 15% and a density of 2.08 g / cm ³ . After hydrolysis with a 10% aqueous solution of sodium hydroxide and washing from sodium hydroxide with water, the copolymer is then treated with a 10% aqueous solution of hydrochloric acid at a temperature of 95-98 ° C for 6 hours to obtain ion-exchange groups in the form of -SO ₃ N. The copolymer is washed with water from hydrochloric acid and dried. The resulting copolymer has an EM 1230,

= 6 · 10 ⁵ ,

= 1.43 and functional groups —SO ₃ N. The copolymer, as in Example 17, was dissolved at 70 ° C. in ethanol to obtain a solution with a copolymer concentration of 15 wt.%. The resulting solution is used in the manufacture of an ion-exchange membrane in the form of a film. A membrane in the form of a film is obtained by pouring a solution of such a thickness onto the glass of the indicated solution so that after removal of the solvent a film with a thickness of 80 μm is formed. The glass with the solution poured on it is placed in a thermostat and the solvent is evaporated with a gradual increase in temperature with exposure at 22 ° C for 10 min and at 80 ° C for 40 min. After removal of the solvent, the membrane (film) had a thickness of 80 μm and a tensile strength of 25 MPa. The resulting film was used as a membrane in the manufacture of membrane electrode blocks (OIE) for water electrolysis. To obtain the electrode material in a glass container, 0.92 g of a platinum black catalyst (particle size 0.06 μm) is mixed with 2.2 g of a 6% solution obtained by dissolving the copolymer of Example 8 (crystallinity 16.5%, density 2.084 g / cm ³ ,

= 6.2 · 10 ⁵ ,

= 1.42, functional groups —SO ₃ H, EM 1400) in isopropanol at a temperature of 80 ° C for 2 hours. The resulting viscous mass is applied to one of the surfaces of the dried membrane obtained as described above in the form of an air-dry film with a diameter of 100 mm by spraying a mixture of such a thickness that, after removal of the solvent, the electrode material layer has a thickness of 10 μm. Then the film is placed in a thermostat and heat treated with a stepwise rise in temperature: holding at 40 ° C for 15 minutes, at 70 ° C for 40 minutes. After that, the membrane is removed from the thermostat, cooled to room temperature, and the same electrode material is applied on its other surface in the same way, placed in a thermostat and heat treated in the manner described above. The obtained OIE is tested during electrolysis of water. A current collector made of porous titanium with down conductors is pressed onto the OIE on both sides, the assembly obtained is compacted using a plate coupler, immersed in a vessel with distilled water, and an electric current of 0.5 A / cm ^{2 is} supplied at 90 ° C for 1 hour. Then the assembly is installed in the cell for electrolysis of deionized water. The voltage on the block was 1.62 V at a current density of 1 A / cm ² and a temperature of 100 ° C.

Example 20

=7· 10⁵,

=1,41. В кругло донную колбу, объемом 500 мл, снабженную мешалкой, термометром и обратным холодильником, загружают 6 г указанного гидролизованного сополимера с размером частиц 100-500 мкм, 94 г диметилформамида, включают мешалку и растворяют сополимер при температуре 140° С в течение 1,5 ч. Сополимер полностью растворяется в указанных условиях. После фильтрования раствор имеет концентрацию 6 мас.%.The copolymer obtained in example 11, with a degree of crystallinity of 18% and a density of 2.085 g / cm ^{3 is} used to obtain a solution with a concentration of 6 wt.%. Before dissolving, the copolymer powder is hydrolyzed with a 10% aqueous NaOH solution at 95 ° C for 12 hours, after which the hydrated copolymer is washed from NaOH and dried in an oven at 95-98 ° C. After hydrolysis, the copolymer contains -SO ₃ Na groups and has EM 2500,

= 7 · 10 ⁵ ,

= 1.41. A 500 ml round bottom flask equipped with a stirrer, thermometer and reflux condenser was charged with 6 g of the indicated hydrolyzed copolymer with a particle size of 100-500 μm, 94 g of dimethylformamide, the stirrer was turned on and the copolymer was dissolved at a temperature of 140 ° C for 1.5 h. The copolymer is completely soluble in these conditions. After filtration, the solution has a concentration of 6 wt.%.

The resulting solution is used to make a super acid catalyst. The polyethylene granules are placed in a Buchner funnel and attached to a Bunsen flask. Then this flask is evacuated, and the solution is gradually poured into the funnel in an amount sufficient to ensure that all the granules are coated with it and, after removal of the solvent, have a coating thickness of 5-10 μm. Then the vacuum is turned off and the granules are dried at 22 ° C for 20 minutes and at 40 ° C for 20 minutes. After removing the solvent, the granules coated with a layer of a copolymer, which is a super acid catalyst, are used in the transalkylation of 4-methylphenol to 4-methyl-2,6-ditretbutylphenol. The yield of 4-methyl-2,6-ditretbutyl-phenol was 83%.

Example 21

An extrusion film of a thickness of 90 μm is obtained from a TFE-HEPE copolymer with -SO ₂ F functional groups obtained in Example 4 by extrusion on a laboratory extruder at a temperature of 250 ° C. from a melt of the copolymer. The film has a tensile strength of 27 MPa. The resulting film is hydrolyzed with a 15% aqueous solution of potassium hydroxide at 95 ° C for 12 hours, and then treated with a 5% aqueous solution of hydrochloric acid at 95 ° C for 4 hours. After hydrolysis, the resulting membrane has functional groups —SO ₃ H and EM 1100. The membrane was used in the manufacture of the MEA for electrolysis of water.

=6,9· 10⁵,

=1,41 функциональные группы -SO₃Н, ЭМ 1300) в изопропаноле при температуре 80° С в течение 1,5 часов. Полученную вязкую массу наносят на одну из поверхностей вышеуказанной мембраны (в виде воздушно-сухой пленки диаметром 100 мм) методом полива смеси такой толщины, чтобы после удаления растворителя слой электродного материала имел толщину 10 мкм. Затем мембрану помещают в термостат и термообрабатывают при ступенчатом подъеме температуры: выдержка при 40° С в течение 15 мин, при 70° С - в течение 40 мин. После этого мембрану вынимают из термостата, охлаждают до комнатной температуры и аналогичным образом на другую ее поверхность наносят тот же самый электродный материал, помещают в термостат и термообрабатывают указанным выше способом. Полученный МЭБ испытывают при электролизе воды. К МЭБ с обеих сторон прижимают коллектор тока из пористого титана с токоотводами, уплотняют полученную сборку с помощью стяжки плит, погружают в сосуд с дистиллированной водой и подают электрический ток силой 0,5 А/см² при 90° С в течение 1 часа. Затем сборку устанавливают в ячейку для электролиза деионизованной воды. Напряжение на ячейке составило 1,68 В при плотности тока 1 А/см² и температуре 100° С.To obtain the electrode material in a glass container, 0.92 g of a platinum black catalyst (particle size 0.06 μm) is mixed with 2.2 g of a 6% copolymer solution obtained by dissolving the copolymer of Example 7 (crystallinity 16%, density 2.083 g / cm ³

= 6.9 · 10 ⁵ ,

= 1.41 functional groups —SO ₃ H, EM 1300) in isopropanol at a temperature of 80 ° C. for 1.5 hours. The resulting viscous mass is applied to one of the surfaces of the above membrane (in the form of an air-dry film with a diameter of 100 mm) by pouring a mixture of such a thickness that, after removal of the solvent, the layer of electrode material has a thickness of 10 μm. Then the membrane is placed in a thermostat and heat treated with a stepwise rise in temperature: holding at 40 ° C for 15 minutes, at 70 ° C for 40 minutes. After that, the membrane is removed from the thermostat, cooled to room temperature and the same electrode material is applied to its other surface in the same way, placed in a thermostat and heat treated in the manner described above. The obtained OIE is tested during electrolysis of water. A porous titanium current collector with down conductors is pressed onto the OIE on both sides, the assembly obtained is sealed with a plate screed, immersed in a vessel with distilled water, and an electric current of 0.5 A / cm ^{2 is} supplied at 90 ° C for 1 hour. Then the assembly is installed in the cell for electrolysis of deionized water. The voltage on the cell was 1.68 V at a current density of 1 A / cm ² and a temperature of 100 ° C.

Example 22

From the copolymer obtained in example 17 (crystallinity 16%, density 2.083 g / cm ³ ), with functional groups —SO ₂ F on a laboratory extruder at a temperature of 260 ° C., tubes with an inner diameter of 550 μm and a wall thickness of 100 were obtained from the melt microns. The tubes were hydrolyzed with a 15% aqueous solution of potassium hydroxide at a temperature of 95 ° C for 20 hours and washed with water from potassium hydroxide. After hydrolysis, the copolymer had functional groups —SO ₃ K (EM 1300). The obtained tubes were used to dry humid atmospheric air (air humidity was 98%), at an ambient temperature of 20-22 ° C. The relative humidity of the atmospheric dried air was 10%.

Example 23

An extrusion film of a thickness of 50 was obtained from a TFE-VGE copolymer prepared according to Example 3 with -SO ₂ F functional groups (crystallinity 11%, density 2.974 g / cm ³ ) by extrusion on a laboratory extruder at a temperature of 240 ° C from a copolymer melt. microns. The film had a tensile strength of 25 MPa. The resulting film was hydrolyzed with a 15% aqueous solution of potassium hydroxide at 95 ° C for 10 hours, and then treated with a 5% aqueous solution of hydrochloric acid at 95 ° C for 4 hours. After hydrolysis, the membrane had functional groups —SO ₃ H (EM 1000) and was used in the manufacture of OIE for fuel cells.

To obtain the electrode material in a glass container, 0.9 g of an electrocatalyst — platinum black (particle diameter 0.09 μm) is mixed with 0.03 g of an electrically conductive inactive material — carbon black with a particle size of 0.01 μm. Then, 3.5 g of a 6% solution obtained by dissolving the copolymer of Example 8 with functional groups —SO ₃ H (EM 1400) in isopropanol at 70 ° C. for 1 hour was added to the resulting mixture. The resulting viscous mass is applied to one of the surfaces obtained as described above for the membrane (films with a diameter of 100 mm) by smearing the mixture with a layer of such a thickness that, after drying, the layer of electrode material has a thickness of 6 μm. Then the membrane is placed in a thermostat and treated with the next stepwise rise in temperature: it is kept at 20-22 ° С for 10 minutes, at 60 ° С - 40 minutes, at 80 ° С - 20 minutes, at 90 ° С - 20 minutes. After that, the membrane is removed from the thermostat, cooled to room temperature and the same electrode material is applied to its other surface in the same way, then it is again placed in the thermostat and heat treated in the manner described above. The fabricated OIE is tested in a fuel cell as follows. A carbon cloth impregnated with polytetrafluoroethylene dispersion (TU 6-05-1246-81) is placed on both surfaces of the electrode layers of the obtained OIE and compressed. Then, carbon collectors of current are applied to both surfaces of the OIE and the assembly is installed in the fuel cell. OIE studies are carried out at 80 ° C when gas is supplied to the fuel cell: hydrogen - to the anode chamber at a pressure of 1 atm and oxygen - to the cathode chamber at a pressure of 1.2 atm. The following characteristics are obtained:

cell voltage 0.84-0.85 V,

current density 700 mA / cm ² .

The fuel cell worked stably for 3,000 hours, after which the process was stopped and the OIE was removed from the cell. Visual inspection of the OIE did not observe any changes.

Example 24

=5· 10⁵, =1,44. В круглодонную колбу объемом 500 мл, снабженную мешалкой, термометром и обратным холодильником, загружают 20 г порошка указанного гидролизованного сополимера с размером частиц 100-500 мкм, 80 г диметилацетамида и растворяют сополимер при температуре 140° С в течение 2 часов. Сополимер полностью растворился в указанных условиях. Затем раствор охлаждают до комнатной температуры и фильтруют через капроновый фильтр. После фильтрации раствор имел концентрацию 20 мас.%.The copolymer synthesized according to example 5, with a degree of crystallinity of 12% and a density of 2.079 g / cm ^{3 is} used to obtain a solution with a concentration of 20 wt.%. Before dissolution, the copolymer is hydrolyzed with a 10% aqueous solution of lithium hydroxide (LiOH) at a temperature of 96 ° C for 12 hours, after which the hydrolyzed copolymer is washed with water from lithium hydroxide and dried in a thermostat at a temperature of 95-98 ° C. After hydrolysis, the copolymer contains groups —SO ₃ Li and has an EM of 1160,

= 5 · 10 ⁵ , = 1.44. A 500 ml round bottom flask equipped with a stirrer, thermometer and reflux condenser was charged with 20 g of the powder of the indicated hydrolyzed copolymer with a particle size of 100-500 μm, 80 g of dimethylacetamide and the copolymer was dissolved at a temperature of 140 ° C for 2 hours. The copolymer is completely dissolved under the indicated conditions. Then the solution is cooled to room temperature and filtered through a nylon filter. After filtration, the solution had a concentration of 20 wt.%.

The resulting solution is used in the manufacture of a film for air humidity sensors. The film is obtained by pouring the solution onto glass with a layer of such a thickness that, after drying, a film 40 μm thick and 50 × 50 mm in size is formed. The glass with the solution deposited on it is placed in a thermostat and the solvent is evaporated with a gradual increase in temperature with exposure at 22 ° C for 10 minutes, at 80 ° C for 20 minutes, at 140 ° C for 20 minutes. After that, the glass with the film formed on it is used as a sensitive air humidity sensor, working on the principle of changes in resistance when the moisture content of the film changes. A device with the specified humidity sensor responds to changes in air humidity within 20-100%.

Example 25

=3,9· 10⁵,

=1,43. Раствор получают аналогично примеру 17, но растворяют 10 г указанного сополимера в 90 г изопропилового спирта. После фильтрации раствор имеет концентрацию 10 маc.% и используется для пропитки пористой пленки из политетрафторэтилена (ПТФЭ) толщиной 430-450 мкм с пористостью 30-35%. Из пористой ПТФЭ-пленки вырезают диск диаметром 73 мм и площадью 41,8 см² и помещают в воронку Бюхнера, присоединенную к колбе Бунзена. Устройство подключают к водоструйному насосу (разрежение 150-200 мм рт. ст.). В воронку наливают 50 мл указанного выше 10%-ного раствора сополимера, включают насос, затем насос отключают, пропитанную ПТФЭ-пленку вынимают и сушат в термостате при ступенчатом подъеме температуры от 20 до 80° С (20° С - 20 мин, 80° С - 40 мин), после чего пропитанную пленку используют в качестве фильтра для очистки расплава металлического галлия (при 70° С) от механических загрязнений. Скорость фильтрации расплава составляет ~ 270 г· ч/см².The TFE copolymer with VGE obtained in Example 10 with a crystallinity of 11.5% and a density of 2.079 g / cm ^{3 is} used to obtain a solution with a concentration of 10 wt.%. Before dissolution, the copolymer is hydrolyzed with a 12% aqueous solution of potassium hydroxide (KOH) at a temperature of 90-95 ° C for 16 hours. Then the hydrolyzed copolymer is washed from potassium hydroxide and dried in a thermostat at a temperature of 95-98 ° C. After hydrolysis, the copolymer contains functional groups —SO ₃ K and has an EM of 1100,

= 3.9 · 10 ⁵ ,

= 1.43. The solution is obtained analogously to example 17, but 10 g of the indicated copolymer are dissolved in 90 g of isopropyl alcohol. After filtration, the solution has a concentration of 10 wt.% And is used to impregnate a porous film of polytetrafluoroethylene (PTFE) with a thickness of 430-450 μm with a porosity of 30-35%. A disc with a diameter of 73 mm and an area of 41.8 cm ^{2 is} cut from a porous PTFE film and placed in a Buchner funnel attached to a Bunsen flask. The device is connected to a water-jet pump (vacuum 150-200 mm RT. Art.). 50 ml of the above 10% copolymer solution are poured into the funnel, the pump is turned on, then the pump is turned off, the impregnated PTFE film is removed and dried in a thermostat with a step-wise rise in temperature from 20 to 80 ° С (20 ° С - 20 min, 80 ° C - 40 min), after which the impregnated film is used as a filter to clean the gallium metal melt (at 70 ° C) from mechanical impurities. The melt filtration rate is ~ 270 g · h / cm ² .

Example 26

The solution obtained in example 25 is used in the manufacture of an ion-selective membrane to separate pentene from pentane. A membrane in the form of a film is obtained by pouring a solution of such a thickness onto the glass of the indicated solution so that a film with a thickness of 50 μm is formed after drying. The glass with the solution poured on it is placed in a thermostat and the solvent is evaporated with a gradual increase in temperature with exposure at 22 ° C for 20 min and at 80 ° C for 30 min. After removal of the solvent, the membrane (film) has a thickness of 50 μm. The resulting membrane is placed in a 1 molar solution of silver nitrate (AgNO ₃ ) and incubated therein for 12 hours at a temperature of 20-22 ° C. After that, the membrane with functional groups -SO ₃ Ag is washed with water from the residues of the silver nitrate solution and used for separation of a mixture of pentene and pentane in a ratio of 1: 1. A mixture of pentene and pentane is fed into a high pressure chamber.

The differential pressure of the membrane was 10 kPa. Based on the analysis of the composition and amount of pentene in the receiving chamber, the selectivity coefficient was 40 in favor of pentene, the permeability of pentene is 7.13 · 10 ^-9 mol · cm ^-2 · s ^-1 and pentane is 1.79 · 10 ^-10 mol · cm ^-2 s ^-1 . The plant productivity was 70 ml / min.

,

, плотность, степень кристалличности, ПТР) за счет введения в жидкую реакционную среду предварительно гидролизованного сополимера ТФЭ с ВСГЭ в виде дисперсии во фторсодержащем органическом растворителе, в то время как по способу-прототипу регулирование свойств сополимера возможно только за счет изменения концентрации реагентов и условий проведения процесса (температура, давление), что не позволяет получать сополимеры с заданным комплексом свойств (

=2-7· 10⁵,

=1,41-1,46, степень кристалличности 10-18%, плотность 2,07-2,084 г/см³, Т_пл=210-260° С, ПТР=7-100 г/10 мин при 270° С). Указанный комплекс свойств, достигаемый при получении сополимера ТФЭ с ВСГЭ по заявляемому способу, обеспечивает возможность использования сополимера для изготовления методом экструзии прочных тонких пленок, трубок и других изделий, которые могут применяться как мембраны, например при электролизе воды (см. пример 21), в топливных элементах (см. пример 23), для осушки газов (см. пример 22). Кроме того из указанного сополимера после гидролиза можно изготовить концентрированные растворы (не менее 6-20 мас.%) и получать из них методом полива прочные тонкие пленки, газоразделительные полые волокна, например для выделения аммиака из аминосодержащих смесей (см. пример 17), пропитывать различные субстраты, например пористые материалы (фторопласт-4, поликапроамид, асбест, бумагу, полипропилен и др.). Так, например, тонкие пленки могут использоваться как мембраны, например при электролизе воды (см. пример 19), для очистки фтористого водорода (см. пример 18), разделения смеси пентена с пентаном (см. пример 26), а пропитанные материалы - для очистки металлического галлия (см. пример 25), для получения суперкислого катализатора (см. пример 20) и др. По заявляемому способу могут быть получены сополимеры с заданным комплексом свойств в интервале эквивалентных масс 1000-2500.As can be seen from the above data, the claimed method in comparison with the known method of the prototype allows to obtain copolymers of TFE with VGE, with the ability to be processed into products with a thickness of less than 100 microns (films, tubes) by extrusion and to form concentrated solutions after hydrolysis (at least 6-20 wt.%), suitable for the manufacture by irrigation of thin, less than 100 microns, films, hollow fibers with a wall thickness of 30-80 microns. These thin products cannot be obtained from the copolymer obtained by the prototype method. The copolymers of the present method have improved thermal stability of 0.04-0.1% compared with the copolymer of the prototype method of 0.43-0.52%, i.e. thermal stability, 5-10 times higher than the thermal stability of the copolymer according to the prototype method. The inventive method allows you to simply control the properties of the resulting copolymers (

,

, density, crystallinity, MFR) due to the introduction into the liquid reaction medium of a pre-hydrolyzed TFE-HPSE copolymer in the form of a dispersion in a fluorine-containing organic solvent, while according to the prototype method, controlling the properties of the copolymer is possible only by changing the concentration of reagents and conditions process (temperature, pressure), which does not allow to obtain copolymers with a given set of properties (

= 2-7 · 10 ⁵ ,

= 1.41-1.46, crystallinity 10-18%, density 2.07-2.084 g / cm ³ , T _pl = 210-260 ° C, MF = 7-100 g / 10 min at 270 ° C) . The specified set of properties achieved when producing a TFE-HES copolymer by the present method makes it possible to use the copolymer for extrusion of durable thin films, tubes and other products that can be used as membranes, for example, in the electrolysis of water (see example 21), fuel cells (see example 23), for drying gases (see example 22). In addition, from the specified copolymer after hydrolysis it is possible to produce concentrated solutions (at least 6-20 wt.%) And obtain durable thin films from them, by gas separation hollow fibers, for example, to separate ammonia from amine-containing mixtures (see example 17), impregnate various substrates, for example, porous materials (fluoroplast-4, polycaproamide, asbestos, paper, polypropylene, etc.). For example, thin films can be used as membranes, for example, in the electrolysis of water (see example 19), for the purification of hydrogen fluoride (see example 18), the separation of a mixture of pentene with pentane (see example 26), and the impregnated materials for purification of gallium metal (see example 25), to obtain a super acid catalyst (see example 20), etc. By the present method can be obtained copolymers with a given set of properties in the range of equivalent masses 1000-2500.

The inventive method allows the copolymerization process under mild conditions at temperatures of 20-35 ° C, which makes the process more technologically advanced, less dangerous and more economical.

Claims (7)

1. A method for producing perfluorinated copolymers with sulfonyl fluoride functional groups by copolymerizing tetrafluoroethylene with perfluorocarbon vinyl ether having the structural formula CF ₂ = CF – O – CF ₂ –CF (CF ₃ ) –O – CF ₂ –CF ₂ –SO ₂ F in a medium a fluorine-containing organic solvent or in bulk under the influence of a radical type initiator - perfluorinated peroxide at elevated pressure with replenishment of the reaction medium with tetrafluoroethylene during the copolymerization process, characterized in that before starting the copolymerization in the reaction the ionic medium is introduced preformed hydrolyzed tetrafluoroethylene copolymer with 9.5-15 mol.% perfluorocarbon vinyl ether of the above structural formula in an amount of 0.3-0.66% by weight of the liquid reaction medium, and the specified hydrolyzed copolymer is introduced into the reaction medium in the form dispersions in a fluorine-containing organic solvent, and as a perfluorinated peroxide, a peroxide selected from the group consisting of bis-perfluoro- (2-oxa-para-methyl-dioxane-propionyl) peroxide, bis-perfluoro- (2,5,8 -trime l-3,6,9-trioxa-dodecanoyl) peroxide, bis-perfluoro- (cyclohexanoyl) peroxide, or mixtures thereof, and the process is carried out at a temperature of 20-35 ° C and a pressure of 0.25-0.6 MPa s obtaining a copolymer containing 3.5-19 mol.% perfluorocarbon vinyl ether of the above structural formula. 2. The method according to claim 1, characterized in that the dispersion of the hydrolyzed copolymer in a fluorine-containing organic solvent with a concentration of 10-20 wt.% Is used. 3. The method according to claims 1 and 2, characterized in that when using bis-perfluoro- (2-oxa-para-methyl-dioxane-propionyl) peroxide, the copolymerization is carried out at a temperature of 20-25 ° C and a pressure of 0.25- 0.6 MPa. 4. The method according to claims 1 and 2, characterized in that when using bis-perfluoro- (2,5,8-trimethyl-3,6,9-trioxa-dodecanoyl) peroxide, the copolymerization is carried out at a temperature of 25-30 ° C and a pressure of 0.26-0.6 MPa. 5. The method according to claims 1 and 2, characterized in that when using bis-perfluoro- (cyclohexanoyl) -peroxide, the copolymerization is carried out at a temperature of 30-35 ° C and a pressure of 0.28-0.6 MPa. 6. The method according to claims 1 and 2, characterized in that when using a mixture of bis-perfluoro- (2-oxa-para-methyl-dioxane-propionyl) peroxide with bis-perfluoro- (2,5,8-trimethyl- 3,6,9-trioxa-dodecanoyl) -peroxide in a mass ratio of 1: 6, respectively, the copolymerization is carried out at a temperature of 23-28 ° C and a pressure of 0.25-0.6 MPa. 7. The method according to claims 1 and 2, characterized in that when using a mixture of bis-perfluoro- (2,5,8-trimethyl-3,6,9-trioxa-dodecanoyl) peroxide with bis-perfluoro- (cyclohexanoyl) -peroxide in a mass ratio of 1: 5, respectively, the copolymerization is carried out at a temperature of 28-35 ° C and a pressure of 0.27-0.6 MPa.

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