CA1048200A - Method for preparation of cation exchangers by substitution of hydrophilic polymeric gels - Google Patents

Abstract

Method for preparation of cation exchangers by substitution of hydrophilic polymeric gels.

ABSTRACT OF THE DISCLOSURE
The invention relates to a method for preparation of hydrophilic cation exchangers by a chemical modification of crosslinked copolymeric gels containing reactive hydroxyl groups and based on hydroxyalkyl, oligogylcol or polyglycol acrylates and methacrylates and hydroxyalkylacrylamides or hydroxyalkylmethacrylamides. The modification is carried out in reactions of hydroxyl groups with halogenalkane acids and their derivatives, anhydrides and halides of dicarboxy-lic acids or carbodiimides. If the modification agent contains several reactive groups, the remaining functional groups after modification may be allowed to react with dicarboxylic, polycarboxylic, hydroxycarboxylic or amino-carboxylic acids, or phosphoric or sulfuric acid, halogene-epoxides, diepoxydes or polyepoxides. The hydroxyl groups can be also modified by oxidation to carboxylic groups by common oxidants. The gels used for modification may also contain alkoxido reactive groups and they have generally the homogeneous, semiheterogeneous or macroporous character.
The ion-exchanging gels prepared in this way are suitable for sorption and chromotographic separations, especially for separation of sensitive biological materials.

Description

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The invention relates to a method for transformation of non-ionogenous hydrophilic polymer gels into cation exchangers by a suitable chemical substitution of the hydroxyl group.
Macroporous and semimacroporous hydrophilic gels of a methacrylate type proved to have a number of advantages in comparison with the hydrophilic gels based on polydextr~n, consisting above all in the high chemical resistance of their fundamental polymer met~ix and its superior mechanical strength.
The gels are noted for the minimum abrasive wear at laboratory and plant handlings, absence of swelling and the possible easy control of the pore size distribution during the synthesis.
Very valuable features of these gels are also the large inner surface of particles and their ability to stand high pressures at considerably high flow rates!in a column without defects.
The properties predestinate the gels for substitution trans-formations into ion e ~hangers. Similarly as polydextran, cellulose or starch, also the synthetic hydrophilic gels based on hydroxy derivatives of acrylic and methacrylic acid contaln a great number of reactive hydroxyl groups able to bind chemically ionogenous functional groups under suitable , reaction conditions.
An objective of this invention is a method for preparation of cation exchangers by substitution of hydroxyl groups of synthetic hydrophilic acrylate and methacrylate , gels, wherein the preparation of the cation exchangers is 3 carried out ~, .

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in reactions in which the h~droxy ~roup of the polrmer takes part. A very efEective reaction is the reaction of the hydroxyl group with halogenoalkylearboxylic acid or its salt in an alkaline medium is aclueous solutions or in organie solven-ts. These reaetions were formerly usecl for substitutlon of cellulose, ?olydextrans and stareh by ehloroacetic or chloropropionic aeic'. However, the reaetion with the synthetie gels based on hydroxy aerylates and methacrylates proeeeds extraordinarily smoothly ancl gives high yields. IGn exehangers with bonded earboxylic funetional group are formed by oxidation of a part of -CH2OH group into earboxylie groups or by the reaetion oE hydroxyl ~roups of the gel with di.earboxylie aeids or their anhydri.des under formation of aeid esters.
A bivalent group of phosphorie aeid may be bonded to khe gel matrix by means oE a reaction with phos?horyl triehloride, phosphorie aeid or phosphorus pentoxide (US Patent No. 4,031,037). However, substitution of the hydroxyl group is advantageously earried out by heating with phosphates N~H2PO~, Na2HPO~ and Na5P3Oll in an aqueous medium-~he strongly aeidie funetional group -S03~ is introdueed i.nto aromatie poly(styrene-co-divin~lbenzene) ion exchangers by direet sulEonation. Hydrophilic gels of the polydextran type are usually modified by means of halogeno-sulfonie aeicl ;~ 3 ,.. .. .. . .. ~ . .. . . ~ . . , . .. . . . , . . ... . . .` . ... .. . ...... ~ .
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or its salt of by means of cyclic sulfone / , 2 2 O\ I , CE~2 - CH2 Chlorosulfonic acid or sulfur trioxide react with starch in pyridine or triethylamine givin~ the sulfo derivative.
An important advantage of hydroxyacrylate and hydroxy-methacrylate gels is their high chemical stability under conditions of the modification reaction which allows to use even very drastic reagents without destruction of the fund-amental gel skeleton.
The reaction described in examples proved suita~lefor the preparation of anionic derivatives of hydroxyacrylate and hydroxymethacrylate gels. Cation exc~angers of various types are formed in this way, the weakly, medium and strongly acidic functional groups of which are anchored in a homogeneous, semiheterogeneous or macroporous matric by the covalent b~nd. ~ -- Advantageoys properties of this matrix remain preserved even after the modification reaction. The hydroxymethacrylate gels have higher stability in the hydrolysing medium in comparison to the stability of the hydroxyacrylate gels~ The cation exchangers mentioned in examples were prepared above all for the purpose of sorption and chromatography of biopolymers and the r degradation products, however, their application is by no means limited by this fart. The following examples also do not limit in any way the objective of~the invention~

A copolymer of 2-hydroxyethyl methacrylate with ethylene dimethacrylate (5 g), having the molecular weight exclusion limit 100,000, was added to the solution of 15 g ~ of chloroacetic acid in 30 ml of 40% NaOH. The mixture was tho-roughly stirred and heated to 90C. The mixture was heated to this temperature for 13 hours~ Then it is was cooled and the gel was filtered off, extracted with hot water, washed ` ~4~3Z~() with 20% HCl, water, 10% HCl, water, methanol, acetone and ether.
The gel was dried in air and then in vacuum. The exchange capacity was 1 mequiv/g.

A copolymer of 2-hydroxyethyl methacrylate with ethylene dimethacrylate (5 g) having the molecular weight exclusion limit 100,000 was swallen in 30 ml of 40% NaOH, cooled to 0 C and a solution of 15 g of sodium chloracetate in 30 ml of distilled water was added. The mlxture wa~ allowed to stand for 30 min and then heated to 80 C and kept at this temperature for further 10 hours. The product wa~ filtered off and then washed is the same way as described in Example 1.
The exchange capacity was 1.7 mequiv/g~ -A copolymer of 2-hydroxyethyl methacrylate with ethylene j dimethacrylate (1 g) having the molecular weight exclusion limit 780,000 was suspended in a solution of 4 g of potassium permanganate and 4 g of sodium carbonate in 40 ml of water.
The ~ixture was heated to 75C for 13 hours. The mixture was cooled and the gel was filtered off, washed with water, concentrated nitric acid, concentrated hydrochloric acid, and a mixture of these acids in the ratio 1:10. Then it was washed with water, methanol, acetone and ether and dried in air and in vacuum. The exchange capacity was then determined and IR spectrum recorded.

copolymer of diethylene glycol monomethacrylate with ethylene dimethacrylate (2 g) having the molecular weight ' exclusion limit 100,000 was added to the cooled solution of 5.5 g of chromium tr~xide in 7.5 ml of water. The mixture was allowed to stand overnight. The product was filtered of, washed with water,-solution of sulfite, water, 5% hydroxide, 4,~

water, 5% HCl, water, acetone and ether. The oxidation was followed from changes in IR spectrum.

The same copolymer as in Example 1 tl g) was added to a mixture of 4 ml o~ dimethylsulfoxide and 2 ml of acetan-hydride. The mixture was stirred and placed in a bath at 75C.
After heating for 16 hours, the product was filtered off, washed with acetone, water, acetone and ether. The product was dried in vacuum and the oxidation was followed from changes in IR spectrum.

A copolymer of triethylene glycol monomethacrylate w1th methylenebi~acrylamide (1 g) having the molecular weight exclusion limit 150,000 was swollen in 10 ml of porydine.
After 30 min. 2 g o~ maleic anhydride was added to the mixture.
The mixture was heated for 10 min to 100C. The gel was then filtered off, extracted with pyridine, washed with concentrated hydrochloric acid, water, 30% NaOH, methanol, 10% methanolic hydroxide, methanol, water, 10% HCl, water, methanol, acetone ~ ~ and ether. The product was dried in air and then in vacuum.
- The determined exchange capacity was 1.6 mequiv/g.

The same copolymer as in Example 1 ~1 g) was swollen in 10 ml o~ pyridine. After 30 min, 2 g of phthalanhydride was added to the solution. The mixture was thoroughly stirred `
and placed in a bath heated to 90C. A vessel with the reaction , .
mixture was removed after 15 hours, the mixture was cooled , ~ and the gel was ~iltered off. The product was washed with ,:, water~ 30% HCl, water, 10% NaOH, water, methanol, 10% methanolic 30 NaOHd methanol, water, again with methanol, acetone and ether.

i The product was dried in air and then in vaccum. The determined ; exchange capacity of the product was 1.6 mequiv/g. .
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A copolymer of 2-hydroxyethylacrylamide with ethylene diacrylate (1 g) having the molecular weight exclusion limit 100,000 was heated with 2 g of 9uccinic anhydride and 6 ml of triethylamine to 95C ~or 6 hours. The product was filtered cff, washed with hot water, concentrated hydrochloric acid, water, 30% NaQH (shortly)-, water, methanol, 10% methanolic ;
hydroxide, methanol, water, again with methanol, acetone and - ether. The gel was dried in air and then in vacuum. The capacity of this product was 1.8 mequiv/g O . '`.

The same copolymer as in Example 1 (1 g~ was added to 6 ml of cooled chlorosulfonic acid. The mixture was cooled during addition and then allowed to stand for 10 minutes. Dioxan was added to the mixture and the mixture with dio~an was shaken and poured into a great excess of precooled 5% solution of NaOH. The product was washed with water, extracted with dioxan, washed with acetone, pyridine, water, concentrated hydrochloric acid, water and acetone. The determined capacity of the product 20 wa~ 1.7 maquiv/g.
EXAMPLE 10.
, The same copolymer as in Example 1 (1 g) and 4 g of sodium hydrogen sulfite were mixed with 10 ml of hot water.
The mixture a~ter dissolution was placecl in a block heated to 230 - 250C. When the great part of water was evaporated, the mixture was again wetted in the way that water was slowly added to the mixture in such amount that it kept out with evaporation. The heating was carried out for 20 hours and the mixture was then cooled and extracted with hot water. The 30 product was filtered o~f, washed with distilled water, 10%~ -~
hydrochloric acid, water, 10% sodium hydroxide, water, 10%

hydrochloric acid, water, methanol, acetone and ether. The ~ 7 -1~8Z~3 gel was dried in air and then in vacuum and the content of sulfur was followed by the elemental analysis.

A copolymer of 2-hydroxypropyl methacrylate with ethylen~ dimethacrylate (1 g) having the molecular weight exclusion limit 100,000 was swollen in 5 ml of cooled 30~/O
solution of NaOH. The mixture was cooled to 5 - 10C, the excessive hydroxide was sucked off and 1 g of sodium 2-chloro-ethylsulfonate in 3 ml of water was added to the solution.

The mixture was well stirred, heated to 75C and 3 ml of 50%
NaOH was gradually added to it within 20 min. The mixture waq then heated for further 6 hours. The product was washed with water, concentra-ted hydrochloric acid, waterl 20% NaOH solution, water, methanol, water, 10% hydrochlor~c acid, water, methanol, acetone, and ether. The gel was dried in air and then in vacuum.
The content of sulfur in the product was determined by the elemental analysis.

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Sodium hydrogen phosphate (4 g) was dissolved in 20 ml of distilled water. The same copolymer as in Example 1 (1.5 g) was added to this solution. The mi~ture was stirred and " " ~

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placed in a thermosta-ting block heated to 23Q - 25~C. ~fter all water was evaporated, the reaction mixture was continuously wetted with water to be all the time in the contact with steam as it was described in Example 10. After 25 hr of heating, the product was extracted with hot water, washed with distilled ~-water, concentratecl hydrochloric acid, water, 10% NaOH solution water, 10~ hydrochloric acid, water, methanol and acetoneO The gel was dried in air and then in vacuum. The co~tent of phosphorus in the product was determined.
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- Sodium alkoxide of a hydroxymethacrylate gel (1 g) having the molecular weight exclusion limit 300,000 (prepared according to the US No. 3,974,111) was allowed to react with 1.5 g of ethyl bromoacetate in 10 ml of dry dioxan at 60C for 3 hours. On completion of the reaction, the gel was filtered off, repeatedly washed with dioxan and water and subjected to hydrolysis in 0.1 N NaOH (20 ml) at 100C for 4 hours. The gel was again washed with water, transferred into the H-cycle and its exchange capacity was determined.

;' ' ' , A copolymer of 2-hydroxyethyl methacrylate with j ethylene dimethacrylate (2 y) was thoroughly mixed with 10 ml of 50~ NaOH solution. The hydroxide was moderately sucked off, 5 ml of epichlorohydrine was added and the mixture was thoroughly stirred and heated to 110C for 2 hr. The product was washed with acetone, quickly with water, then with ~`
acetone and ether and dried in vacuum. ~y the elemental - 30 analysis, 1.2% Cl was found. After heating to 60C ~ith 20% hydrochloric acid for 1 hr, washing a~ drying, 3.11% Cl was determined.

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A copolymer of 2-hydroxyethyl methacrylate with ethylene dimethacryla~e (1 g), having the molecular weight exclusion limit 100,000 was mixed with 10 ml of dried dioxan, 10 ml of 70% benzene solution of synhydride was added and the mixture was allowed to stand for 1/2 hr. The suspension was filtsred and the gel washed with dioxan and benzene~
Butanediepoxide (2 g) which was dried with the molecular sieve Nalsit A4 (Trademark) was added and the mixture was allowed to stand for 3 days. A part of the product was hydrolysed with 2 N HCl, washed with acetone and water ~ .
and contained 0.73% Cl according to the elemental analysis.
The residue was heated to 70C for 6 hoursand contained according to the elemental analysis 2.96% Cl after .,~ .
~; hydrolysis in 2 N HCl and washing.
"' ,~ EXAMPLE 16 A Grignard reagent was prepared from 10 g of !'~ Mg and 2~ ml of dried ethyl bromide and then slowly dropwise :
added to 10 g of a dried copolymer of 2-hydroxyethyl metha- :
crylate with ethylene dimethacrylate, having the molecular .: weight exclusion limit 100,000, under cooling and without access of moisture. The mixture was stirred Eor 20 minutes, the gel was then -:: /

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sucked off, sever~;time~ d~canted with dried ether and stored in a desiccator. A part of the sample wa~ suspended in water and titrated with HCl on phenolphthalein. The gel after fil-tration was dried and weighed. The capacity was 2.4 meguiv of organometal per 1 g.
Dried epichlorohydrine (1.5 ml) was poured into 1 g of the gel after reaction with the Grignard reagent. The mixture was allowed to stand for 30 min, then heated to 100 C
; for 10 min and rapidly cooled. The gel was filtered off, decanted with acetone, washed with methanol, 0.5 N HCl and water. Then it was kept in 0.5 N HCl for 3 days, washed with waterj methanol, acetone and ether and dried. The elemental analysis showed 2~07% Cl~
Another 0.2 g of the gel after the reaction with Grignard reagent was mixed with 0.3 g of dried butanediepoxide and heated to the chosen temperature without access of air.
After the required reaction time, the gel was washed with acetone and water, filtered off and covered with the solution of 5 g of NaHS03 in 10 ml of waterO The gel after reaction was thoroughly washed with water, methanol, acetone and ether, dried and analyzed on the content of S and Br.

Reaction Temperature Average analytical content, %
time,hr C Br S

2~ 25 1 1.6 6 38 1 1.9 4 ~8 1.~ 2.0 1 60 1 2.3

3 60 1.1 2.2

4.5 60 1.2 2.05 0-5 90 1.6 1 gO 1.3 1.8 -3 90 1.15 1.5 6 90 1.1 1.6 1 ~ .
: ..,.,,,,, '., ,' : ' ExAMpLE 17 ._ The gel after reaction with Grignard reagent (0.2 g) according to Example 16, was mixed with 0.4 ml of dry epichloro-hydrine and heated for the required time without access of moisture. The gel was then washed with acetone, water, ethanol and water and heated with the excess of 20% aqueous NaHSO3 to 60C for 10 hours~ The gel was then thoroughly waqhed with water, methanol, acetone and ether, dried and subjected to the elemental analysis on- the content of S and halogens ~.g. Cl ?

Time, hr Temperature, C Content, %
S
38 3.12 0.56 0.5 1.03 0.5 3,03 . , ; A copolymer of 2-hydroxyethyl methacrylate ~ith ethylene dimethacrylate having the molecular weight e~clusion limit 100,0Q0 was swollen in 2 N NaOH, hydroxide solution was moderate ly sucked off and the gel was mixed with about a twofold volume excess of 30% aqueous NaOH and with the same volume of epichlorohydrine. The mixture was thoroughly stirred, placed in a thermostated bath and, after reaction, cooled, The gel was then washed with water, acetone, water, methanol and water, covered with the excess of 20% aqueous NaHS03 and heated to 60C Por 10 hours. The gel was thoroughly washed with water, then with methanol, acetone and ether and dried, The content of S and Cl was determined by the elemental analysis.

Time,hr. Temperature,C Content,%
S Cl 38 0.73 0.17 S 60 0.92 0.37 0.84 0.59 ... . . .
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EXAM~LE 19 A flask was charged with 5 g of a copolymer of 2-hydroxyethyl methacrylate with ethylene dimethacrylate, having the molecular weight exclusion limit 100,000. A solution prepared from 5 g of KMnO4 and 5 g of Na2C03 in 20 ml of hot water was diluted wi~h 20 ml of water and poured into the gel under intense stirring. The mixture was stirred and heated to 78C
for 12 hr. The gel was washed with water, the mixture of HCl and NHO3, waterl 0.5 N NaOH, water, 0.5 N HCl, water, acetone and ether. A total exchange capacity 2.5 mequiv/g was determined. Fig. 1 shows the titration curve of the ion exchanger in the H+ form obtained by titration with 0.1 N
NaOH. Values of pH are plotted on the axis of ordinates ; and the consumption of the titrant on the axis of abcissas.

A copolymer o~ 2-hydroxyethyl mçthacrylate with ethylene dimethacrylake after reaction with 10% solution of phosgene in benzene at 30C for 5 hours (4 g) having the molecular weight exclusion limit 300,000 was mixed 1.2 g of taurine in 10 ml of distilled watex. The mixture was rapidly stirred and allowed to stand for 30 minutes. The gel was then washed with water, pyridine, water, methanol, acetone, water, 0.5 N
HCl, ethanol and acetone and dried. The sulfur content according to the elemental analysis was, 2.2%, N content by the Kjehldal method was 1. 02%. Fig; 2 shows the titration curve of the ion exchanger in the ~ ~orm; pH values are ;
plotted on the a~is of ordinates and the consumption of titrant (0.1 N NaOH) in millequivalents on the axis of abcissas.

A copolymer of 2-hydroxyethyl methacrylate with~
ethylene dimethacrylate (1 g), having the molecular weight exclusion limit 100,000, was dispersed in 6 ml of distilled ~ 3 ., , 1~48~

water. The mixture w~s allowed to stand for 10 ~inute~ and the excessive hydroxide was then sucked o~f on a tritted-glass filter. The gel was heated with 1 g of iodoacetic acid and 2 ml of water to 80C for 2 hours, washed with water, 2 N NaOH, water, ethanol, acetone, water, 2 N HCl, water, ethanol, acetone and ether and dried. Tha total exchange capacity determined was 1~3 mequiv/g. Fig. 3 shows the titration curve of the ion exchanger in the H+ ~orm. Coordinates have the same significance as in Example 20.

A copolymer of 2-hydroxyethyl methacrylate with ethyIene dimethacrylate (5 g), having the molecular weight ~ ;
exclusion limit 100,000, was placed in a three-necked flask, covered with 100 ~ of dried acetone and the mixture was stirred and cooled to 5C. At this temperature and under vigorous stirring, 10 ml o~ chlorosuL~onic acid was dropwise added. The mixture was stirred for 30 min, then 20 ml of pyridine was added and stirred for another 1 hr at 0C. The product was filtered off and the gel was washed with water, acetone, methanol, water, 2 N HCl, water, ethanol, acetone and ``~
ether and dried. According to the elemental analysis, the content of Cl and S was 0 and 1.20%, respectively. Fig. 4 shows the titration curve of the ion exchanger in the H form.
Coordinates have the same significance as in Example 20.
EXAMPI,E 23 A three-necked flask was cha~ged with 20 g of a dried copolymer of 2-hydroxyethyl methacrylate with ethylene dimethacrylate, having the molècular weight exclusion limit 300,000 and the particle size 32 - 40 ~m, and 210 ml of ethyl acetate (analytical grade, dried over the malecular sieve Kalcit A3) was added. The mixture was stirred and cooled to -20C. In 150 ml o~ ethyl acetate (dried in the same way), :.. , - , : ' ~

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50 g of chlorosulfonic acid was dissolved under cooling. The solution was then cooled to -20C and gradually added to the gel under stirring and cooling within 17 mlnutes, so that the temperature was kept at -16C. The gel was filtered off, washed with ëthyl acetate, acetone, ethanol and water, decanted with water, washed with ethanol, acetone and ether and dried. The elemental analysis gave 4.73% S and 0% Cl, the total exchange capacity was 3.1 mequiv per 5 ml of the swollen gel.

A dried gel of a copolymer of 2-hydroxyethyl methacry-late with ethylene dimethacrylate, having the molecular weight I exclusion limit 100,000, was mixed with a moderate excess of butyllithium in tetrahydrofuran. The reaction was carried out under stirring and cooling for 30 min in a nitrogen atmosphere.
The gel was then washed with dried tetrahydrofuran. About 0.2 g of this gel was mlxed with a moderate volume excess of dried epichlorohydrine (or butadiepoxide) and heated with 0.5 N
HCl to 70C for 6 hr. The content of Cl was then determined (C1 I) after this reaction, the gel was subjected to the reaction with SOC12 and the Cl content was again determined (Cl II), while Cl I corresponds to the content of exposides)~

82~30 r, me, hr Temperature, Content of Cl~ Type of C 1 11 epoxi de 3 25 I.. 04 5.71 epichlorohydrine

5.5 70 6.92 9.55 epichlorohydrine 3.5 25 1.41 5.95 butanediepoxide

6.5 7Q 4.94 7.12 butanediepoxide ~ ~
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A flask was charged ~ith 7 g of the gel, which was transformed into ~i alkoxide by the procedure described in Example 24 and 27 g of butanediepoxide was added (dried over the molecular sieve Potasit A3 (T~ademark)). The flask was ~ -heated to 70C, maintained at this temperature for 3 hours under occasional stirring and without access of moisture and then allowed to stand overnight. The mixture was then heated for 10 min to 100C under a reflux condenser. The temperature ;
inside the flask reached 130C and the mixture was kept at this temperature for 5 min. Then it was cooled, washed with acetone, e-ther r acetone, rapidl~ with cold water and the ~ :~
20 large~excess of acetone, with ether, CHC13 and ether and `
dried in vacuum.

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The gel modified with butanediepoxide according to Example 25 (0.3 g) was mixed with 0.79 g of K2HPO4.3H2O and ~-1.5 ml of water. The mixture was allowed to stand for 1 hr -~ :
at the labora.tory temperature, then heated to 95C for 4 hours and eventually allowed to stand at the laboratory temperature for 2 da~vs. The gel w~ ~iltexed off, washed with water, etha- -~6 : ::
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nol and acetone. Found: l. 07% P . In the same way, the gel containing 0.61% P was obtained with NaH2P04.4H20.
EX~MPLE 27 The yel modified with butanediepoxide according to Example 25 (0.3 g) was mixed with a solution of 0.4 g of Na2SO3 in l ml of water. The mixture was allowed to stand at the la~oratory temperature for l hr, then heated t~ 950c for 4 hr and allowed to stand at the laboratory temperature for 2 days. The gel was then filtered off, thoroughly washed with ~ater, ethanol, acetone and ether and dried in vacuum.
The content of sulfur was determlned by the elemental analysis.
For treatment with Na2S03, 1.59% S was found. ~he modifications ~r with Na2S205, Na2S203, NaHS03 and KHS03 were carried out in the same way.
Sample H20,'ml Salt, g Type S,%

~ A 1 0.4 Na2 3 l,59 ; ~ B l O . 56 . Na2S205 l . 74 ` C l 0.5 'Na2S23 3-37 , ' D l 0.55 NaHS03 l. 84 ...
E 0.2 0.2 Na2S203.5H2O 2.61 F ! 1 0.62 ICHS03 1 . 5 , . .
A part of the sample containing 2.61% S was mixed ;'~ ' with concenkrated HN03 for 30 min. The gel was washed with water, ethanol and acetone. Found: 1.4% S (G) . Figs. 5,6 and 7 show the titration curves of gels marked B, D and F in the Table. Coordinates have the same significance a~ in Example 20.
EX~MPLE 28 ' A 250 ml flask wa~ charged with 8.3 g of a copolymer .
of 2-hydroxyethyl methacrylate with ethylene dimethacrylate, . :,.
'' 30 having the molecular'weight exclusion limit 30Q,000 and the ..... . .
particle size 20 - 40 ~Im. The gel was covered with a solution '''~ containing 9 g of KMnO4 and 10 g of NaC03 in 100 ml of water .. .. . .

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and vigorously stirred without heating fox 30 rnin. The tempe-rature was raised to 72 C during further 30 min and the mlxture was stirred for 3.5 hr at this temperature. The gel was allowed to s-tand with KMnO~ for another 70 hr at the laboratory temperature, then filtered off, washed fivetimes with 100 ml of distilled water, 200 ml of the mixture HCl -HN03 lol, threetimes with 200 ml of distilled water, 200 ml of the mixturs HCl - HNO3 1:1, threetimes with 200 ml of distilled water, twice with 200 ml of ethanol, threetimes with 200 ml of distilled water, twice with 100 ml of 10% NaOH
solution, and fivetimes with 100 ml of distilled water. Before titration, the gel was additionally wasl1ed with ethanol, acetone and ether and dried in vacuum. The determined total exchange capacity of the ion exchangers was 3.5 mequiv/g and 6.62 mequiv per 5 ml of the gel column.
EXAMPLE_29 A flask was charged with 8.S ~ of a copolymer of 2-hydroxyethyl methacrylate with ethylene dimethacrylate, having the molecular weight exclusion limit 500,000 and the particle size 20 - 40 ~m. The gel waslmixed with 50 ml of distilled pyridine and 20 g of phthalanhydride was added.
The mixture was stirred and heated to 50C as long as all anhydride dissolved and then it was placed in a thermostated bath at 38C for 4 days. Then it was additionally heàted to 72C ~or 14 hours. The gel was washed with 100 ml of acetone, threetimes with 200 ml of ethanol, twice with 500 ml of distilled water, fivetimes with 100 ml of ethanol, with 100 ml of pyridine, threetimes with 200 ml of ethanol, twice with 200 ml of acetone, tentimes with 100 ml of water, twice with 100 ml of 10% NaOH solution, fivetimes with 300 ml of water, twice with 100 ml of water, twice with 100 ml of 10% NaOH, fivetimes with 300 ml of water,twice with 200 ml of 15% HCl, fivetimes with ` ~ ~8 .. . .
. .

~ 321J0 300 ml of water, fourtimes with 15% HCl and with water as long as Cl ions were detected~ The sample was then addition-~ally washed with ethanol, acetone and ether and dried and its determined total exchange capacity wa~ 1.7 mequiv/g. Fig. 8 shows the titration curve of the exchanger in the H+ form.
Coordinates have the same significance as in Example 20.

~ flask equipped with a stirxer, thermometer and a dropping funnel was charged with a g of a copolymer of 2-hydroxyethyl methacrylate with ethylene dimethacrylate, havingthe molecular weight exclusion limlt lpO,OOO and the particle size 60 - 120 ~m, and 30 ml of dried ethyl acetate. The mixture was cooled to 20 C and 4.5 ml of chlorosulfonic acid was dropwise added to it from the dropping funnel within 15 min. The samples were then withdrawn, washed with water, 10% NaOH, water, ethanol, acetone and ether and dried. Then the content of S and Cl was determined.

Time from the beginning Temperature Average content, %
of reaction, min C S Cl . . ... .. _ _ -20 4.15 0.6 -20 3.55 O.S
-~ 4 3.5 O.S
140 + 4 3.5 0.5 240 ~ 4 3.2 0 a 7 455 ~ 4 1.8 0.5 15~0 + 4 1.5 0.6 A 250 ml flask was charged with 35 ml of a copolymer of 2~hydroxyethyl methacrylate with ethylene dimethacrylate, having the molecular weight exclusion limit 300,000 and the particle size 20 - 40 ~m, and 50 ml of distilled pyridine was added followed by a mixture of 25 g of succinic anhydride with ,.. - .. ~,~ .
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8~0 20 ml of pyridine. The mixture was stirred and heated to 40C and then allowed to stand for 2 hours with occa~ional ;~
stirring as lon~ as all anhydride dissolved. The mixture wa~ than placed in a thermosta-ted bath at 38 C for 114 hr.
The gel was filtered off, washed threetimes with 100 ml of pyridine to turn white, once with 100 ml of acetone and twice with 100 ml of pyridineO Then, 100 ml of distilled pyridine and 25 g of succinic annydride were added to the gel, stirred and heated to 73C for 5 hr. The whole washing procedure was repeated and the gel was again heated with 25 g of anhydride and 100 ml of pyridine to 73C for 2 hr. Finally, the gel was washed with pyridine, twice with 300 ml of acetone, twice with 200 ml of methanol, twice with 200 ml of ethanol, fivetimes with 200 ml of water, fivetimes with 200 ml of 2 N HCl, tentimes with 200 ml of water, threetimes with 300 n~ of 2 N ~ICl, twenty-times with 200 n~ of water, threetimes with 300 ml of ethanol, threetimes with 300 ml of acetone and twice with 200 ml of etherO The total capacity in a colun~ was determlned as 2.2 mequiv/ 5 ml of the swollen gel.
EXAMæ~E 32 An ampoule was charged with 7 ml of concentrated H2SO~ and 3 n~ of 25% oleum and the mixture was cooled to -20C.
At this temperature, 0.3 g of a copolymer of 2-hydroxyethyl methacrylate with ethylene dimethacrylate, having the molecular weight exclusion lin~t 100,000, was added and the mixture was allowed to stand under occasional stirring at -20C for -~
40 minutes. Then it was rapidly poured into a large excess of cooled and stirred water. The gel was filtered off, washed with water, decanted and washed with 2 N NaOH, water, methanol, acetone and ether. After drying~ 4.4/0 S was found.

An ampoule was charged with 8 ml of concentrated .
..

.. . . . . .
. . : : , .. . . .

~4~2~30 ~ulfuric acid and 2 ml of 25% oleum. The mixture was cooled -to -10C and 0.3 g if a copolymer of 2.hydroxyethyl methacrylate with ethylene dimethacrylate, having the molecular weight exclusion limit 100,000, was added at this temperature. The mixture was shaken and maintained at -10 C for 10 minutes.
The gel was then filtered o~f and washed with concentrated sulfuric acid, 50% H2So4, water, methanol, water, 2 N NaOH, methanol, acetone and ether; 2.6% S was found in the dried sample.
~ EXAMPLE 34 A copolymer of 2-hydroxyethyl methacrylate with ethylene dimethacrylate, having the molecular weight exclusion limit 100,000, was mixed with a large volume excess (i.e. about twentyfold volume) of sodium hydroxide solution of the given concentration in an ampoule. The mixture was then placed in a thermostated bath at the chosen temperature. After the required period of time, the samples were withdrawn and thoroughly washed with water, ethanol, water, 2 N HCl, water, 2 N NaOH and water. Then they were allowed to stand in 2 N HCl for 1 hr and washed with waterias long as Cl ions were detected in the eluate~ The gel washed in this way was further washed with ethanol, acetone and ether and dried in vacuum~
The total exchange capacity was determined for each sample (c.f. the table)~

2~

. .

, ., ., ~ , . .
.. . . .
. , ., `

2~
Time,mun _ 'r~m~erature,c_ 0 initial gel -~ 0~19 180 38 0.5 0.270 360 38 0.5 0.308 180 38 2 0.366 360 ' 3~ 2 0.445 210 38 30 % 1.02 Or5 O~ 277 180 60 0.5 0.317 360 60 0~5 0.370-2 0.4 180 60 2 0.5 360 60 2 0.55 30 % 0.60 180 60 30 % 0.765 360 60- 30 % 1.12 0.5 0.364 180 90 0.5 0.423 360 90 0.5 0.562 2 0.60 180 90 2 0.750 , 360 90 2 1.20 120 90 30 % 0.80 180 90 30 % 2.16 3~0 90 30 % 5.0 FigO 9 shows the course of the copolymer hydroly5is in the dependence on time, concentration of NaOH and temperature.
The exchange capacity in mequiv/g i~ p~otted on the axis of ordinates, time inhr on the axi~ of abcissas.

A solution of 5 g of NaHSO3 and 8 g of epichlorohydrine in 10 ml of water was heated to 75C for 90 min under stirring ,.

482~0 with a vibration stirrer. The product was cooled and ~eparated crystals were filtered off, washed with water and acetone and recrystallized from water. The elemental analy~is proved a structure Cl -CH2CH(OH)-S03Na~ This product (0.9 g) was mixed with 0.5 g of NaOH, 0.5 g of a copolymer of 2-hydroxyethyl methacrylate with ethylene dimethacrylate, having the molecular weight exclusion limit 100,000, and 3.6 ml of distilled water. '~ ' The mixture was stirred and heated to 80C for 10 hr. The ~ -washed and dried product contained 0.40% SO ~ ' ' 10 EXAMPLE 36 ' A conic flask was charged with 5.5 g of CrO3 and

7.5 g of water~ On dissolution, 2 g of a copolymer of 2~
hydroxyethyl methacrylate with ethylene dimethacrylate was ' added, having the molecular weight exclusion limit 100,000. ~;
The mixture was heated to 40C, then cooled to 20C and allowed to stand at the laboratory temperature overnight. The gel was !
;, washed with water, ethanol, acetone and ether and dried in vacuum~ The exchange capacity was 2.1 mequiv/g.
'~ , EXAMPLE 37 ,, --A copolymer of 2 hydroxyethyl methacrylate with ethylene dimethacrylate (0.5 g), having the molecular weight exclusion limit 100,000, was added to a solution of 2 g of CrO3 in 3 ml of water cooled to 5C. The mixture was allowed to stand at t'he laboratory temperature for 2 days. The gel was then washed with water, ethanol, acetone and ether'and dried. The exchange capacity was 1.7 mequiv/g.
For comparison, oxidation of Sephadex was carried out in the similar way: 7 g of CrO3 was dissolved in 20 ml of water and 2 g of Sephadex G-75 was added at the laboratory temperature. '~he gel dissolved completely during 2 minutes.
F~AMPLE 38 A solution of 1 g of CrO3 in 15 ml of pyridine wa~

~ 23 . . . ,~ , .

.

.. , - . . ~ . , , 1~82~
cooled to 5C and 1 g of a copolymer of 2-hydroxyethyl methacrylate with ethylene dimethacrylate, having the molecular weight exclusion limit 100,000, was added. The mixture was stirred and then allowed to stand at the laboratory temperature for 38 hours. The gel was washed and dried in the same way ~-as in Example 37. The exchange capacity was 1.6 me~uiv/gO

A copolymer of 2-hydroxyethyl methacrylate with ethylene dimethacrylate (0.5 g), having the molecular weight exclusion limit 100,000 was added into a solution of 1 g of CrO3 in 15 ml of pyridine and the mixture was heated to 75C
for 15 hours. The gel was washed and dried in the same way as in Example 37. The exchange capacity was 3.5 mequiv/g.

A copolymer of 2-hydroxyeth~l methacrylate with ethylene dimethacrylate (0.5 g~, having the molecular weight exclusion limit 100,000, was added to a solution of 1 g of CrO3 in 5 ml of acetanhydride and heated to 75C for 15 hours.
; The gel was then washed and dried in the same way as in Example 37. The exchange cap~city was 3.2v mequiv/g.

A copolymer of 2-hydroxyethyl methacrylate with ethylene dimethacrylate (0.5 g), having the molecular weight exclusion limit 100,000, was added into a mixture of 2 ml of dimethylsulfoxide and 1 ml of acetanhydride. The mixture was sealed in an ampoule and heated to 75C for 16 hours.
The gel was then washed and dried as in Example 37~ The exchange capacity was 1~7 mequiv/gO
For comparison, Sephadex G 7S was treated with acetanhydride: 3 g of Sephadex G 75 medium was stirred in 30 g of dimethylsulfoxide and 20 ml of acetanhydride. The mixture was heated to 75C and the gel completely dissolved during :~ 2 ~ :

~48~

6 hours.
EXAMPLE ~ 2 . . .
A 500 ml three-necked flask was charged with 31 g o~ a copolymer o 2-hydroxyethyl methacrylate with ethylene dimethacrylate, having the molecular weight exclusion limit 300,000, and 300 ml of ethyl acetate (analytical grade, dried `~
over the molecular sleve Kalsit A3) was added. The mixture was stirred and cooled to -20C and a mixture of 150 ml of ethyl acetate and 30 ml of chlorosulfonic acid (VEB, Apolda, GDR) cooled to -20C was dropwise added during 12 minutes.
During the reaction, the temperature was maintained at -20 to -14C by`coollng and stirring of the mixture. Chlorosulfonic acid was added in two equal portions; after addition of about 1/5 of the volume of the second portion no increase of tempera-ture by the reaction heak was already absevedO After addition of C1503H during 12 minutes, the mixture was stirred ~or further 3 min and then poured on a fritted-glass filter. The separated gel was wa~shed with ethy~ acetate, acetone, ethanol and water ; and then dispersed in 1 7 of distilled water and decanted in 500 ml portions of distilled water. A part of the gel was withdrawn, washed on the filter with water, ethanol, water, 2 N HCl, water, ethanol and acetone and used for determination of the e~change capacity. The product was seventimes decanted with 500 ml oflwater, wa~hed on a filter fivetimes with 500 ml of water, threetimes with 300 mL of ethanol, threetimes with 300 ml of acetone, fivetimes with 200 ml of water, twice with 300 ml of 2 N NaOH, with water to the neutral reaction, with 8 M
urea, 2 M NaCl and 2 N NaOH, twice with 300 ml of 2 M H2S04, 2 N HClf once with 200 ml of 2 N HCl and water as long as the eluate showed Cl ions. The product contained 0% Cl and 1.18 S and the exchange capacity was 1.6 mequiv/ 5 ml.

A mixture of proteins containing pepsinogen, human : ~ 25 2~)(3 serum alb~in and chymotrypsin was chromatographed on thi~ yel (Fig. 10). Elution by means of a two-~tep linear gradient of the ionic strength and pH. Buffer solutions:
A - 0.05 M NH4OH - formic acid, pH 3~5 B - 0.3 M NH~OEI - acetic acid, pH 6.0 C - 1 M N~140H - acetic acid, pH 8.0 ~ 0~5 M KCl .
The gel modified with phosgene by a reaction with 10% phosgene solution in benzene at room temperature for 5 hoùrs was poured into water and heated to 50C for 3~ min.

The gel was then washed with water, 2 N HCl and wat_r as long as : Cl ions were present in the eluate. The dried sample had the exchange capacity 1.6 mequ.iv/g.
.

A dry gel of a copolymer o~ 2-hydroxyethyl methacrylate with ethylene dimethacrylate (5 g), having the molecular weight exclusion limit 100,000, was dispersed in 20 ml of dry tetra-hydrofuran. An about fivefold amount of butyllithium, calculated on the number of -OH groups of the gel, in 20 ml of tetrahydro-~
furan was added to the suspension during stirring and cooling to 0C. After addition of butyllithium, the mixture was stirred at the room temperature for 0.5 hr. The gel was washed :j and dried and exhibited the excpange capacity 2.2 mequiv/g.

. A copolymer of 2-hydroxyethyl methacrylate with ;~
ethylene dimethacrylate, having the molecular weight exclusion limit 300,000 and the particle size 10 - 25/um, was modified according to the Example 36 and packed into a column of a diameter 5 mm and Z40 mm long in a buffer solution of 0.03 M ~ :
.30 NH40H - HCOOH (pH 3.5). The through-flow rate was varied and the dependence of the pressure gradient and of the through-~low . ::
rate was studied and compared with the phosphorylated cellulose :
---` " 2~ :
,, ~
.

.

~9L82~
Whatmann Cellulose P70. Fig. 11 shows the plotted dependences of th~ gradient on the volume through-flow rate~

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.:

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Claims (5)

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows:

1. Method for the preparation of hydrophilic cation exchangers wherein crosslinked copolymers of acrylate and metha-crylate monomers prepared by a suspension copolymerization of mono-mers selected from the group comprising hydroxyalkyl methacrylate, hydroxylalkyl acrylate, oligo- and polyglycol methacrylates, oligo-and polyglycol acrylates, hydroxyalkylacrylamides and hydroxyalkyl-methacrylamides with crosslinking comonomers containing two or more acryloyl or methacryloyl groups in the molecule selected from the group comprising alkyl di- and polyacrylates, alkyl di-and polymethacrylates, glycol di- and polyacrylates, glycol di-and polymethacrylates and divinylbenzene, and containing reactive hydroxyl groups are modified by the reaction with halogenoalkylcarboxy-lic acids and their derivatives, with anhydrides and halides of dicarboxylic acids, or with carbodiimides, forming materials which contain functional groups giving anions by dissociation.

2. Method as set forth in claim 1, wherein in the modification reaction of the hydroxy group, a compound is used which contains several reactive groups able to react with the hydroxyl group, and the remaining reactive functional groups after this reaction are allowed to react with compounds selected from the group comprising dicarboxylic and polycarboxylic acid, hydroxycarboxylic acids, aminocarboxylic acids, phosphoric acid, sulfuric acid and from the group comprising halogeno-epoxides, di- and polyepoxides.

3. Method as set forth in claim 1, wherein the primary alcohol groups of the gel after completion of the modification reaction are oxidized with the common oxidation reagent to carboxylic groups.

4. Method as set forth in claim 1, wherein the modification reactions are carried out with polymers according to claim 1 which contain alkoxide reactive groups.

5. Method as set forth in claim 1, wherein the copolymers have the homogeneous, semiheteroyeneous or macroporous character.