DE2222905A1 - Polymeric permselective membranes and process for their manufacture - Google Patents

Description

PATENT LAWYERS

DR.-ING. BY KREISLER DR.-lNG. BEAUTIFUL DR.-ING. TH. MEYER DR. FUES DIPL-CHEM. ALEK VON KREISlER DIPL-CHEM. CAROLA KELLER DR.-ING. KLOPSCH DIPL-ING. SEITIN®

COLOGNE 1, DEICHMANNHAUS

Cologne, the 9th, times 1972 Ke / Ax / Bt

Consigllo Nazionale delle Richerche, 1 ,, Via Reno, Rome (Italy)

and

Montecatini Edison S.p.A., Foro Buonaparte Jl _s Milan, Italy

Permselective membranes made of polymeric) material and process for their manufacture

The invention relates to membranes permselective for anions, which consist of a polymeric material containing chemically bound vinyl pyridine and a process for its manufacture of these membranes.

It is known that vinyl pyridine is generally used in the manufacture of polymeric materials, which suitable for the production of permselective membranes. Numerous polymers and copolymers of vinyl pyridine have already become the starting material for the production of permselective membranes that are only permeable to anions, suggested. However, most of these membranes show disadvantages of various kinds depending on the kind of the membrane polymeric material used.

The homopolymers of vinyl pyridine are, if they are pyridine nitrogen is quaternized, water-soluble and, when cross-linked, show very strong water absorption, the is generally above 50 wt .- ^ and too much Swelling of the membranes made therefrom in water leads.

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Ans Bivinylbenzol -vinyl pyr-iäin copolymers can comprises using a method that considerable technical difficulties, membranes are prepared to V a low permselectivity for anion / iron? ■ and in addition by a very strong water absorption, generally greater than. 50 Gew.-Jo is, are marked »

From copolymers of methyl vinylpyridine with butadiene are made using a process in which the polymeric rubber-like materials in the presence of sulfur, Soot and the like in a press for quite a long time are heated to high temperatures, membranes obtained due to the presence of substances that are not Have ion exchange capacity and in the polymer during 5 its processing too. Membranes remain, not homogeneous are.

: Membranes can also be made by grafting vinyl pyridine on polymeric materials of various types and shapes, e.g. synthetic and man-made films, which may previously activated by exposure to high-energy radiation. These membranes are generally characterized by a considerable swelling in water. They generally have a low exchange capacity, while their electrical properties are in no way satisfactory. It also requires their manufacture sometimes long and cumbersome procedures. Eventually be in certain cases non-homogeneous membranes are obtained because Components are present that are chemically inert to ion exchange.

It is also known to use homogeneous anionic membranes Styrene-divinylbenzene copolymers by ChI ormethylation and subsequent amination to produce. The procedure for

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The manufacture of these membranes is, however, a matter of fact complicated and requires conditions under which evaporation does not occur, thereby making it practical becomes extremely difficult.

5 The invention relates to membranes for anions are permeable, consist of polymeric materials that contain chemically bonded vinylpyridine, and do not have the disadvantages mentioned above. The invention includes 'also a process for the production of these membranes.

10 The tasks that the invention turns out to be ¹ permselective membranes which are permeable to anions dissolved I, the included- of chemically bound vinylpyridine \ the polymers are prepared according to the invention from homogeneous and crosslinked terpolymers of butadiene, styrene

15 and vinylpyridine / consist whose nitrogen atoms are whole or

^; partly in quaternary form.

! The membranes according to the invention surprisingly have ^; a combination of good properties, namely moderate ones; Water absorption, excellent mechanical properties,

ί 20 high ion exchange capacity, low electrical resistance \ standing and high permselectivity. They are also in water; insoluble and are characterized with regard to the ion exchange i by a "very high degree of homogeneity, since the

■ ionically active groups an integral part of substitu- ' 25 duck groups form, which are directly attached to the polymer chains,

j that form the membrane are bound.

I ■ ■■ · ■ -. '

j The membranes according to the invention consist of homogeneous,

■ Styrene-butadiene-vinylpyridine terpolymers, the composition of which can vary within wide ranges depending on the chemical, physical, electrical and mechanical properties to be achieved. ]

■ i

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It was found that the exchangeability of the membranes depends on the viny3pyride content. It is also possible that Degree of crosslinking and thus certain mechanical properties of the membrane through appropriate measurement of the butadiene content to stand up. ScM iess3 I depend on the rigidity of the

en
Membrane / and the degree of water absorption predominantly from

Styro] content. .

Particularly suitable for the membranes according to the invention is a group of Po3ymerisaten that in chemically bound form ^J0 3 0 to 40 Mo3 -%, preferably 3 to 5 JJO f-üoj -% styrene, 20 to 60 WloI-%, preferably 25 contain up to 45 mol% of butadiene and 10 to 40 mol%, preferably 15 to 50 mol %, vinylpyridine.

In the context of the invention, the expression "Vinylpyri-5 din "to understand compounds. · the general formula

CH = CH ₂

in which the vinyl group in 2-, 3- or 4-position to the nitrogen atom can stand, R is an alkyl radical having 1 to 10 carbon atoms, e.g. a methyl radical or ethyl radical, and η is 0, 1 or 2. As examples of preferred compounds are 2-vinylpyridine, 4-vinylpyridine, 2-vinyl-5 »methylpyridine, 2-ethyl-5-vinylpyridine and vinyllutidine. The vinyl pyridine can be completely or partially by vinyl quinolines, vinyl piperidines and Like. Be replaced. Likewise, instead of styrene, α-methylstyrene, allylbenzene, vinylnaphthalene and the like can be used. be used. Finally, the butadiene can be replaced by isoprene, chloroprene, dirnethylbutadiene, pentadiene-1, J5 and the like. be replaced.

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Those suitable for making the membranes according to the invention Terpolymers are used by customary known processes for polymerizing the mixture of the three monomers in emulsion, Suspension, mass or solution produced. Do one The mixture of the three is simple and cheap Monomers in an aqueous emulsion in the presence of a polymerization initiator polymerized by the redox type, the polymer latex coagulates and the terpolymer deposited in the process is washed and dried.

The terpolymers prepared in this way are generally soluble in aromatic and chlorinated hydrocarbons and insoluble in aliphatic hydrocarbons. They are characterized by intrinsic viscosities (inherent viscosity) (as determined in chloroform at 30 ⁰ C, the concentration of the terpolymer 0.25 g / 100 ml solvent) in the / are preferably between 0.1 and 4 dl g.

The membranes permselective for anions are made from the

Vinyl pyride interpolymers described below according to the invention a simple and cheap process, .that, consists of the following stages performed in this order:

a) Preparation of a solution of the terpolymer in an organic Solvent in the presence of a free radical initiator which, when heated, causes the crosslinking of the Terpolyrneren able to accelerate.

b) Forming the membrane by pouring the solution onto a glass or metal plate and then evaporating the solvent.

c) crosslinking of the membrane by heating in the presence of a free radical initiator.

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d) Quaternization of the nitrogen atoms of the vinyl pyridine by treating the membrane with mono- and / or polyfunctional] ] en quaternization means.

The method of manufacturing the membranes according to the invention is very simple and can be carried out easily and cheaply on an industrial scale, since it is not necessary is to work in conditions where there is no evaporation, and also the crosslinking in very short tent takes place.

0 As an organic solvent for the preparation of the terpolymer solution in stage a) of the process according to the invention, a wide variety of compounds are suitable with sufficient- Volatility. Particularly good results are obtained when hydrocarbons, e.g. benzene, toluene, xylene, Tetralin and other similar compounds can be used.

The amount of terpolymer in the solution is generally ^: between 5 $ and 60 wt .- #, based on the solution. Good ER ', results of be with Terpolymermengen 10-25 wt -.%! obtain.

As free radical initiators are suitable for the; Process according to the invention those known to those skilled in the art numerous compounds of this kind. Examples are

■ Benzoyl peroxide, Cuniyl peroxide, azo-bis-isobutyronitrile and ι

> mentioned other similar compounds which are able to promote and accelerate the crosslinking of the membrane. ; These initiators are generally used in amounts between 0.1 and 4% by weight , based on the terpolymer.

The solution must be prepared at temperatures below the decomposition temperature of the initiator which forms free radicals. In general, temperatures are preferred worked around room temperature.

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The membrane is produced from the solution in the Step b) of the method according to the invention, by first applying the solution to a glass plate, metal plate or a A plate made of another suitable material with a smooth, even surface is applied and the solvent then applied is evaporated under controlled conditions. For this purpose, the working temperature must be lower than the decomposition temperature of the initiator, but are so high that the removal of the solvent in proportionate

Ii0 is possible for a short time. For these reasons, it is preferred to work at a temperature between 30 ° and 70 ° C. The. The time for the solvent to evaporate depends on the thickness of the membrane to be produced and on the temperature at which the work is carried out. In general, evaporation takes 1 to 40 minutes. This step of the process is generally carried out by keeping the glass plate or plate of other suitable material on which the terpolymer solution has been spread in an oven at the above temperature for the above time

will. ',

The membrane is crosslinked in step e) of the process according to the invention by heating the membrane in the presence of the initiator which forms free radicals. This step of the process is carried out at temperatures and for a time which varies within very wide ranges depending on the type of initiator used. Good results are generally obtained when working at temperatures between 70 ° and 180 ° C for a time of 10 to 240 minutes. In general, for this purpose, the plate of glass or other suitable material is formed on the after evaporation of the solvent the ^membrane: is, for the time mentioned in the above-

Temperature kept in an oven. '

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In order to facilitate the removal of the membrane from the plate, the plate is treated with a lower aliphatic alcohol, for example methanol, ethanol and propanol, after the membrane has been crosslinked. This treatment is at. a temperature carried out, which generally ^{sets between -10 ° and 70 0} C 3 in al 3.

The quaternization of the nitrogen atoms in vinyl pyridine takes place in step d) of the method according to the invention by treating the crosslinked membrane with mono- and / or polyfunctional quaternizing agents consisting of a wide range of compounds known to those skilled in the art can be selected. All of these connections must be sufficiently reactive and able to produce stable quaternary nitrogen atoms by reacting with the tertiary To form nitrogen atoms of vinyl pyridine in the terpolymer.

As examples of monofunctional quaternizing agents, which can expediently be used in the process according to the invention are to be mentioned: alkyl and aryl monohalides and alkyl and aryl sulphates, e.g. methyl, ethyl, propyl, η-butyl, cyclohexyl, dodecyl, hexadecyl and benzyl chlorides, -bromides and -iodides, long-chain alkylbenzene chlorides, bromides and iodides and methyl and ethyl sulphates.

As examples of suitable polyfunctional quaternizing agents for the method according to the invention are to be mentioned:

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Aliphatic, aromatic and alky! Aromatic dihalogen derivatives, e.g. 1,2-dichloroethane, 1,2-dibromoethane, 1,2-diiodoethane, 1,2- and 1,3-dichloropropane, 1,2- and 1,3-dibromopropane, 1,2- and I, j5-Di j od propane, 1,3- and 1,4 -Dl chi or butane, I, j5- and 1,4-dibromobutane, 1,2- and 1,4-diiodobutane, bis- (chloromethyl) -1,2- and -1,4-benzene, bis- (bromomethyl) -l, 2- and -1,4-benzene and other analog connections.

One or more mono- or polyfunctional quaternizing agents or mixtures of one or more monofunctional quaternizing agents with one or more polyfunctional ones Quaternizing agents can be used. When using polyfunctional quaternizing agents takes place in addition to the quaternization of the pyridine nitrogen atoms a further crosslinking of the membrane takes place. In a preferred embodiment, the membrane is first with a polyfunctional and then with a monofunctional Quaternizing agents treated.

The quaternization can involve all or at least 10 % of the pyridine nitrogen atoms present. In the first case, a membrane consisting of strongly basic exchangers (100% quaternary nitrogen atoms) is obtained. In the second case, a membrane is obtained which consists of both weakly basic exchangers and strongly basic exchangers (mixture of tertiary and quaternary nitrogen atoms). _. -.

The quaternization is preferably achieved by treating the Membrane carried out with a solution of the quaternizing agent in a solvent that diffuse through the membrane able. Numerous solvents are suitable for this purpose. Particularly good results are obtained with organic Solvents such as methanol, isopropanol, benzene, toluene, chloroform, acetone and tetrahydrofuran.

The quaternization reaction is according to the invention carried out at temperatures between 20 ° and 110 ⁰ C. The reaction time, which depends on the working temperature and from

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depends on the type of quaternizing agent used, is generally 10 minutes to 5 hours.

The quaternization is preferably carried out in two consecutive Stages performed at two different temperatures. The first stage is at room temperature and in the second stage at one above tree temperature and generally between 60 ° and IO ° C lying temperature worked. In the first In the first stage, the quaternizing agent diffuses within the swollen membrane and partially Quaternization of the pyridine nitrogen atoms. These Quaternization is in the second stage at a higher temperature in a relatively short time completed.

After the quaternization treatment, the membranes are generally stored in water or in aqueous NaCl solutions brought into equilibrium. However, they can also be used in the dry state without permanent Deformation or cracking is preserved, maintaining its original electrical and mechanical properties Preserve properties.

The method according to the invention enables the advantageous production of anions permselective Membranes which are larger than 1 cm in at least two dimensions, and in which the partially or completely quaternized nitrogen atoms are present in polymer chains, which are arranged so that they form a three-dimensional networked structure. These membranes are made by the crosslinking and quaternizing acts They are not damaged in any way, nor are they brittle or brittle from these treatments brittle.

The membranes according to the invention can be made in thicknesses 209848/1 081

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which vary within a very large range and are generally greater than 20 μ . They can advantageously be used in multi-chamber cells for electrodialysis and in the smallest dimensions in conventional ion exchange columns. They are strong, durable, homogeneous and, in particular, have the right degree of water absorption (generally around $ 0 %).

The mechanical properties of these membranes are very well and can be continued by reinforcing materials or by using a suitable carrier be improved. For this purpose, natural or synthetic fibers made from organic can advantageously be used or inorganic polymers or fabrics produced from these fibers perish. Opposite to the membranes according to the invention show excellent properties in relation to these materials Adhesion and Compatibility. Particularly good results are obtained when fabrics made of glass fibers, polyester fibers, Polyamide fibers, polyolefin fibers and fibers of vinyl polymers and the like.

The membranes according to the invention are characterized by a low electrical resistance and a high one Exchange capacity from within a wide range - by adjusting the concentration accordingly the fixed ionic charges can be varied. The ion exchange capacity of the membranes according to Invention is generally above 0.2 miHi-equivalent per gram of dry product.

The membranes quaternized in the chlorine form according to of the invention have an electrical conductivity,

-4 -1 -1 which is generally larger than 1x10 ohm cm They have a high selective permeability for anions. This can be seen from the high potential that comes through

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'These membranes are developed when they are in standard cells of the following types can be used:

Calomel electrode
Saturated KCl salt bridge
5 0.2 molar KCl solution

Membrane according to the invention in the Cl ~ form 0.1 molar KCl solution
Saturated KCl salt bridge
Calomel electrode

30 A concentration potential can be measured at 25 ° C which is very close to the ideal thermodynamic value of 16.08 mV. In other words, the Membranes according to the invention are characterized by transfer numbers which are very close to 1.

.35 · The membranes according to the invention can be used by everyone

Methods are used in which an ion emission! exchange takes place, e.g. for the demineralization and desalination of water, for the recovery and concentration of radioactive materials or of ^! 20 light metals, for the purification of proteins and sugar solutions and for demineralization processes in general. They can be used particularly advantageously for the i desalination of seawater and brackish water; will.

i ²⁵ Example 3

I A) Herste] Jung des Terpo3ymeren

! In a pressure-resistant 3000 m3 autoclave G3as which _was equipped with mechanical stirrer ■, pressure gauges and thermometers, the following Materia3ien were placed under nitrogen:

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Water · . ! ' 200 g

anion-active emulsifier

("Alipa3 Co Kj6", manufacturer GAF Corp., USA) 6.2 g

DispergierrnitteD ("Daxad Jl", manufacturer W.R. Grace, USA) Ig

KOH 2 g

■ Chain transfer device ("MPM", manufacturer
Phillips Petroleum Co, USA) 0.3 g

(NH ₂ ^ ₂ S ₂ O ₈ '0.075 g

Na ₂ S ₂ O 0.030 g

^ -Vinyl pyridine - 30.0 g

Styrene. 20.0 g

Butadiene 50.0 g

The mixture was stirred at 45 ° C. for four hours. The excess butadiene was then removed, whereupon 10 ml of a toluene solution containing 1 g of a crosslinking inhibitor "Santo White Crystals" (manufactured by Monsanto Chemical Co., USA) was added to the mixture. After brief stirring, the resulting aqueous emulsion of the terpolymer was poured into about 3,000 ml of methanol. The rubbery terpolymer thus separated was then washed several times with water and dried. In this case were obtained 55 g of a terpolymer butadiene-Styro3-4 Viny3pyridin-, which had an intrinsic viscosity of 2.4 dl / g was (solution of 0.25 g of the terpolymer in 00 3 ml of chloroform at 3O ⁰ C). The terpolymer had the following molar composition determined by nuclear magnetic resonance:

Butadiene ^ 69 moles- $

Styrene 13 moles ~ $

4-vinylpyridine 20 Mo3 %

This terpolymer was aromatic and chlorinated Hydrocarbons are soluble and in a3iphatic hydrocarbons and carbon dioxide insoluble.

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B) Herste] Young of the membrane

15 g of the terpolymer prepared in the manner described above were dissolved in 85 g of toluene. To the solution were added peroxide at 50 ⁰ C. 0.03 g Cumy]. The solution was then knife coated on a flat glass plate which was then placed in a held at 50 ⁰ C oven. After JO minutes, the oven temperature was brought to 140 ° C. within about JO minutes and held at this value for about one hour.

The film formed was easily peeled off the plate on which it was formed by dipping the plate in ethanol. The film was then immersed at room temperature in a methanol solution containing diiodoethane in the stoichiometric amount of the pyridine nitrogen atoms to be quaternized. The temperature was then brought to 80 ° C. and held at this value for about two hours. The membrane thus obtained was washed with hot methanol to remove the unreacted diiodoethane. The membrane had a thickness of 0.2 mm and was ^% insoluble in all solvents.

C) Properties of the membrane

The membrane made by treatment with an aqueous IN-NaCl solution had been converted into the chlorine form, had the properties given in Table 1.

Table I. characteristic method value Electrical resistance 0) 10 ohm cm transfer number t _nl - (2) 0.99 Exchange capacity D) 2, o'Milliäqui- valent / g Water absorption ( ² O 25 wt. - <fo

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(1) In an aqueous 0.5 N NaCl solution at 25 i O.1 ° C according to the method that is described in "Test Manual for Permselective Membranes", method 601-1, page 156, O.S.W. Report No. 77.

5 (2) In an aqueous 0.5 / 0.25N NaCl solution according to the Method described in "Test Manual for; Permseleetive Membranes", Method 602-1, page I63 O.S.W. Report No. 77.

(3) Described in "Test Manual for Permselective Membranes", 10 Method 502-1, page Γ52, O.S.W. Report No. 77.

(A) Described in "Test Manual for Permselective Membranes", ' Method 412-1, page 120, OSW Report No. '77.

Example 2

; A membrane produced according to Example 1 (B) was with 15 of a methanol solution of methyl used in excess; iodide treated for one hour at 40 ° C. She was then with

washed with hot methanol to remove the unreacted methyl ! To remove iodide. This by treatment with an aqueous

The membrane converted into the chlorine form in NaGl solution had the 20 properties listed in Table 2:

Table 2

Property method value

Electrical resistance (I) * 4 ohm cm ²

Conversion number t _cl ~, (2) ^K 0.97

25 Exchange capacity (3) ^K 2.2 billion

I. valent / g

Water absorption (4) ^K 25 wt .- ^

I κ See footnotes to Table I.

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Example] 3

A terpolymer solution prepared in the manner described in Example 1 (B) was applied to a glass plate with the aid of a rake], which was then placed in an oven kept at 50 ° C. After 30 minutes, the temperature of the oven was increased to 140 ° C. within about 30 minutes and held at this value for about 1 hour. After removal from the plate, the film was immersed in an alcoholic solution at room temperature, based on the Pyridine nitrogen atoms containing the stoichiometric amount of diiodoethane and methyl iodide in an equivalent ratio of 3: 1. The temperature was then raised within ESwei hours from 30 ⁰ to 100 ⁰ G C. After this treatment, the membrane was washed with methanol to remove any unreacted reactants. In this way a 0.2 mm thick membrane which was insoluble in all solvents was obtained. The membrane, which was converted into the chlorine form by treatment with an aqueous IN-NaCl solution, had the properties listed in Table 3.

20 th.

characteristic

! Electrical resistance ι transfer number t », - ! 25 Exchange Assets

Water absorption

ή See footnotes to Table 1

Tabel 3 method value p
7 ohms cm U) * 3, 97 d (2) * 0, 0 milliequiva (3) * 2, lent / g % By weight > W * 26th

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Example 4

A terpolymer solution prepared according to Example 1 (B) was applied with the aid of a doctor blade to a glass plate, which was then placed in an oven kept at 50.degree. After 150 minutes, the temperature was brought to 140 ° C. within 30 minutes and held at this value for one hour. After Entfernung.der film from the glass plate was immersed in an alcoholic solution of _s the methyl iodide contained in excess, and had room temperature. The solution was then brought to 40 ° C. and refluxed at this temperature for one hour. The membrane was then washed with warm methanol to remove unreacted methyl iodide. It now had a thickness of 0.2 mm and was insoluble in all solvents. The membrane, which was converted into the chlorine form by treatment with an IN NaCl solution, had the properties given in Table 4.

Table1e characteristic 4th value Electrical resistance method 0.2 ohm cm ² Transfer number t ", - O)* 0.88 Exchange capacity (2) * 2.4 mil 1 equivalent ent / g Water absorption O)* J55 wt ( ² O *

χ See footnotes to Table 1

Ex iel 5

A net made of polyethylene enterephthalate with a free area of 50 $ and a thickness of 105 / U was immersed in a solution containing 15 g of a terpolymer of the type described in Example 1 (A) and 0.03 S- cumyl peroxide in 85 g Toluene contained. This network was then removed from the solution and placed in a heating cabinet at 50 ^° C. for 60 minutes

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This temperature was then raised to 34o ° C in about 50 minutes and held at this value for one hour. The reinforced membrane thus obtained was immersed in an alcoholic solution containing the stoichiometric amount of diiodoethane and then treated in the manner described in Example 3. The membrane was then treated with methyl iodide in the manner described in Example 2. The transferred by treatment with an aqueous 3N NaCl solution into the membrane contained ChDorform 6NC wt -.% Material ₅ which was active for the ion exchange, and had the mentioned in Table 3.

Tabel characteristic

Method value

Electrical cons & t-ar.d 15 Transfer number t, exchange capacity Water absorption

'CD

5 ohms cm

0.97

1.2 mil equivalent / g

3 8 wt -.%

χ See footnotes of Table 3

Example 6

A Production of the terpolymer

The polymerization xv was carried out in the manner described in Example 1, but starting from a monomer mixture of 55 g of ^ -vinylpyridine, ρ g of styrene and hO g of butadiene. After a polymerization time of 2k hours at ^ ^r j "G ₁ ... the excess butadiene was removed.

Θΐπί ν toluene solution '

whereupon 10 ml / of the corrosion inhibitor "Santo White Crystals" (Manufacturer Monsanto Chemical Cc. USA) added to the mixture “After stirring on the course side, the

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aqueous emulsion of the terpolymer in about 1000 ral ver. thin.s aqueous ammonia (about 5 $ ig) poured. This here separated terpolymers was used several times. Washed water, dissolved in chloroform, redissolved in n-heptane falls and finally dried under reduced pressure. To this. Way were 15 g of a terpolymer with a Intrinsic viscosity of 1.37 dl / g obtained. The terpolymer had the following determined by nuclear magnetic resonance molar composition: '■ ■;

10. Butadiene. ... .46,7-MoI-Ji. _: !

Styrene · 33.6 mole Ji ■ ■. '· ■!

, • ίί-vinylpyridine '39 * 7 MoI-Jg'! '' ^s ■:'. · ■■. '■ -I

■; ■ This terpolymer was present in aromatic hydrocarbons,

■■ soluble and chlorinated hydrocarbons and alcohols;

f 15 insoluble in aliphatic hydrocarbons. ,! "

B) Manufacture of the membrane ".. · *: 'j

! '. "■ - ■ In 70 ml of cyclohexanone, 10 g of the above-described,

,. ■; terpolymers produced in the same way. Do ^:

i · Addition of 0.02 g of cumyl peroxide was the solution with a

\ 20 'squeegee, applied to a flat glass plate, which is then in i

I was placed in an oven kept at 80 ° C. After about

■ ''. one hour the temperature of the furnace was about J50 minutes

ί -, th increased to 140 ° C and; about> white stuneh at this value

j held. The film obtained could be easily removed from the ¹ glass.

; 25 Remove the plate on which it is placed by immersing the plate

[was formed in ethanol. The slide then became the in

ί: 'Example 1 (B) described quaternization treatment

: subject. Here was a-0 _a 2 mm thick membrane ER-

I; hold that was "insoluble in all solvents. ·

1 30 C) Properties of the membrane . . '-

¹ 'The treatment with an IE NaCl solution in the -CbIor-

· ■ "·" "'■ ■ 209848/1081 ■ -' ■. ■■

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The shape converted membrane had that shown in Table 6 Properties.

Table1e characteristic 6th value Electrical resistance
Transfer number t _c , -
Exchange capacity
Water absorption method 4.5 ohm cm ²
0.90
2.8 milliequivalents / g
34 wt .- ^ O)*
(2) *
O)*
(4) *

χ See footnotes to Table 3

, 3 0 example; 7th

A) Preparation of the terpolymer

I '. The polymerization was carried out in the manner described in Example 3 (A), except that 50 g of 2-viny.3.pyridine and 20 g of styro3. and 50 g of butadiene-1 15 standing monomer mixture started. After a poly-I merization time of 6 hours at 40 ° C were! mixed 34 g of a terpolymer separated, which had an intrinsic viscosity of 2.5 d3 / g and the following molar composition:

■ 20 2-Viny3pyridine 12.4 MoI-Ji

I Styro3 53.6 mol%

: Butadiene ■ · 34.0 mol-Ji

; This terpolymer was aromatic and chlorinated

Insoluble in aliphatic hydrocarbons and soluble carbon ¹ 25 hydrocarbons and alcohols.

B) Making the membrane

30 g of the terpolymer prepared in the manner described above were dissolved hot in 60 ml of toluene. After adding 0.02 g of cumyl peroxide, the solution obtained was applied to a smooth glass plate using a doctor blade,

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which was then placed in a held at 5O ⁰ C oven. After 30 minutes, the furnace temperature was increased to 3 40 ° C. in about J> 0 minutes and held at this value for about an hour. The film 3 peeled off easily from the glass plate on which it was formed by immersing the plate in ethanol. It was then subjected to the quaternization treatment described in Example 1 (B). This gave a 0.2 mm thick membrane which was insoluble in all solvents.

c) Properties of the membrane

This is done by treatment with an aqueous IN-NaCl solution The membrane converted into the chlorine form had the properties given in Table 7.

Table 7

characteristic '_ Method value

Electrical resistance (I) * 35 ohm cm ²

Transfer number t _o , - (2) * 0.8l

Exchange capacity (3) 0.9 milliequivalents / g

Water absorption ( ² O "* ^ wt .- $

χ See footnotes from Tabel 1 e ^} 1

Example 8

A) Manufacture of the terpolymer

The polymerization was carried out as described in Example 1 (A) Carried out manner, however, from a mixture of monomers from 40 g of 2-vinylpyridine, 20 g of styrene and 40 g Butadiene was run out. After a polymerization period from 5 hours box 40 C, 13 g of a terpolymer were separated, that has an intrinsic viscosity of 1.5 dl / g and the had the following molar composition;

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2-vinyl pyridine 33.4 mol #

Styrene 22.6 mol %

Butadiene 44.0

This terpolymer was available in aromatic and chlorinated Hydrocarbons soluble and in aliphatic hydrocarbons insoluble.

B) Making the membrane

10 g of the terpolymer prepared in the manner described above were dissolved in 65 ml of toluene while hot. After addition of 0.02 g Cumylperoxyd the solution was coated on a smooth glass plate was placed in a held at 50 ⁰ C oven. After 30 minutes, the temperature of the furnace was brought to 140 ° C. within JO minutes and held at this value for one hour. The film was easily removed from the glass plate on which it was formed by immersing the plate in ethanol. It was then subjected to the quaternization treatment described in Example 1 (B). A 0.2 mm thick membrane which was insoluble in all solvents was obtained.

C) Properties of the membrane

The treatment with an aqueous JN-NaCl solution in the membrane carried over by chlorine was as shown in Table 8 mentioned properties.

Contrary?. Table Ie 8 value characteristic saw? I _n method 4,] OhK c ni ^ Electric moron country (I) ³⁵ overpass? -? nOC "- ~ n 7 (2) ^s r: ■; ;. _^:: 'Ii..i J .1 sii.i Li - ν ti J t.iv / /iusv.auschvor (5) ;;

9 η ¹ ^ .- ■ /:; ^: fs a 1

Membranes made by the method according to the invention from terpolymers having a different composition within the above limits and obtained from butadiene, styrene and monomeric pyridine compounds showed mechanical, chemical and electrical properties similar to those in the examples above 1 to 8 described membranes.

2098 4 B / 1081

Claims (2)

- 24 claims 1.) For anions permselective membranes made of chemically bound vinylpyridine-containing polymers, thereby characterized in that they are made from homogeneous and crosslinked terpolymers of butadiene, styrene and vinyl pyridines the general formula CH = CH ₂ in which the vinyl group can be in the 2-, 5- or 4-position to the nitrogen atom, R is an alkyl radical with 1 to carbon atoms and η is 0, 1 or 2, the nitrogen atoms of which are wholly or at least 10 % in quaternary form . 2.) Membrane according to claim 1, characterized in that they consist of terpolymers which, in chemically bonded form, 10 to 40 moles, preferably 15 to 30 moles of styrene, 20 to 60 moles, preferably 25 to 45 moles -J ^ butadiene and 10 to 40 mol- #, preferably 15 to J> 0 mol- # contain vinylpyridine. 3) Membrane according to claim 1 or 2, characterized in that that they consist of terpolymers in which the vinyl pyridines are wholly or partially by appropriate Vinylquinoline or vinylpjperldine, styrene whole or partly by α-methylstyrene, or allylbenzene Vinylnaphthalene and the butadiene in whole or in part by isoprene, chloroprene, DJmethylbutadiene or 1,3-pentadiene are replaced. Ky. ) Process for the production of membranes according to Claim 1 to J5, characterized in that one a) a solution of the homogeneous terpolymer risate in the presence one through the crosslinking of the terpolymer. Heating accelerates, forms free radicals Initiator manufactures, b) through the membrane! Pour the solution onto a glass or Metal plate and subsequent evaporation of the solvent, c). the membrane by heating in the presence of a free radical initiator and d) the nitrogen atoms of the vinyl pyridines by treatment. the membrane with mono- and / or polyfunctional quaternizing agents quaternized. 20 9 8 4 8/1081