DD284475A5 - PROCESS FOR THE PRODUCTION OF NEW ANION EXCHANGERS - Google Patents

Abstract

The invention relates to a process for the preparation of novel anion exchangers which can be used in molecular biology, in genetic engineering, biotechnology and phytopathology. The polyurethane-based anion exchangers according to the invention have a high binding capacity (400 mg / cm 2) and a high binding stability to DNA fragments, without a reduction in the mechanical strength of the polyurethane moldings. {Anion exchangers, new; Polyurethane anion; molecular biology; Bindungskapazitaet; Bindungsstabilitaet; Strength, mechanical}

Description

Field of application of the invention

This invention relates to a process for the preparation of novel polyurethane-based anion exchangers which can be used in molecular biology, genetic engineering, biotechnology and phytopathology.

Characteristic of the known state of the art

The preparation of polyurethane membranes from solutions is known, see, for. For example, DE-AS 2918027 or DE-OS 3341847. Also known is the preparation of polyurethanes having tertiary or quaternized nitrogen atoms in the main chain, e.g. DE 3152879, Y. lmanishi, Makromol. Chem., Suppl. 12, 83-104 (1985) and M. Ruthowska, J. Appl. Polym. Sci. 311, 469-1482 (1986). In addition, polyurethane membranes with backing fabric are known for making filter material, see e.g. DE-PS 24 60835. All products have in common that the ion-exchange active group is a tertiary or quaternized nitrogen atom located in the polymer main chain.

Furthermore, polyurethanes have become known (DE-OS 1495830), which are prepared using incorporable N, N-bis (hydroxyalkyl) amine alkyl-N, N'-dialkylamines as catalysts. From these polyurethanes elastomers are produced in the first place.

In the investigation of polyurethane membranes with quaternizable nitrogen atoms in the main chain in molecular biological detection method was found that the binding strength to the biomolecules is not sufficient. There is a need for products with increased binding stability between anchor group in the polymer and biomolecule.

Object of the invention

The aim of the invention is to produce new polyurethane anion exchangers with higher binding stability to biomolecules, in particular for use in transfer processes.

Explanation of the essence of the invention

The object of the invention is to produce polyurethane anion exchangers with strongly basic, quaternary nitrogen atoms. According to the invention the object is achieved in that incorporated into the polymer chain compounds with tertiary, quaternizable nitrogen atoms in the side chain and these are quaternized in a subsequent step. Surprisingly, it has been found that biomolecules can be stably bound to polyurethanes which have side chains with quaternary nitrogen atoms

 The incorporable compounds have the following general formula (I):

2 <

R ¹ and R ^{2 are the} same or different hydroxyalkyl or aminoalkyl groups in which the alkyl radical may optionally be substituted by halogens,

R ^{3 is} an alkylene group having 2 to 18 carbon atoms, an arylene group, an alkylarylene or aralkylene group or an alkylene-R ^e -alkylene grouping, in which R ^{6 is} an arylene, oxo, thio -, - NR ⁵ - or a saturated heterocyclic grouping,

R ⁴ and R ^{8 are} identical or different alkyl groups or

3 R ⁴

R -N ^ *, together form a saturated or partially unsaturated alkylene heterocyclic group having 1 to 2

additional heteroatoms, which may be O, S or NR ⁶ . Preference is given to using compounds of the formula (I) in which R ¹ and R ^{2 are} hydroxyalkyl groups, R ^{3 is} a C 1 -C 6 -alkyl group and R ⁴ and R ^{6 are} methyl or ethyl groups. Particularly suitable compounds of the formula (I) are those in which R ¹ and R ^{2 are} hydroxyethyl or hydroxypropyl groups, R ^{3 is} an ethylene or propylene group and R ⁴ and R ^{6 are} methyl groups. Furthermore, compounds can be incorporated which have the following general formula (II):

5 I »),

wherein R ', R ² , R ³ , R ⁴ and R ^{5 have} the meaning as in formula (I) and R ^{7 represents} a hydrogen atom, a halogen atom or an acyl group.

The polyurethanes or polyurethane polyureas prepared according to the invention are prepared from diisocyanates, prepolymers containing isocyanate groups, polyether and / or polyester alcohols, chain extenders and at least one compound of the formula (I) and (II), if appropriate in the presence of solvents and / or diluents, catalysts, fillers and / or other Zusatzstoifan made. This gives polymers having the following structure (III) after quartzization:

backbone

£ j £ 3

wherein R ³ , R ⁴ and R ^{6 are} as defined in formula (I), R ^{8 represents} an alkyl group and X represents a halogen atom or a hydroxyl group. These polyurethanes are novel compounds.

The ratio of diisocyanate to polyether or polyester alcohol is usually between NCO: OH as 2: 1 and 20: 1. The ratio of chain extender to a compound of formula (I) and / or (II) is generally between (based on the equivalents of functional groups) 1: 100 to 20: 1. A ratio of 1: 1 to 4: 1 is preferred. As diisocyanates, aromatic, aliphatic, araliphatic, cycloaliphatic can be used, for. 4,4'-diphenylmethane diisocyanate, tolylene diisocyanate-2,4 or 2,6 or mixtures thereof, 1,5-naphthylene diisocyanate, hexane-1,6-diisocyanate, isophorone diisocyanate, 1,4-cyclohexyl diisocyanate, 4,4'- Dicyclohexylmethyl diisocyanate, xylylene diisocyanate, etc.

As the polyhydroxy compounds, polyether alcohol of ethylene oxide and / or propylene oxide with various diols including water may be used as the initiator. In addition, polytetramethylene oxides, Dihydroxypolybutadiene, polycaprolactones or polyester alcohols from dicarboxylic acids and diols, z. As adipic acid and 1,4-butanediol and / or ethylene glycol.

Chain extenders may be diols, water, diamines or hydrazine. Suitable diols are ethylene glycol, 1,4-butanediol, 1,6-hexanediol, diethylene glycol, hydroquinone bis (2-hydroxyethyl) ether, etc. The diamine used is mainly ethylenediamine.

The reaction can be carried out in the 1-stage process or in several stages in bulk or in solution. The reaction is preferably carried out by a two- or three-stage process in the presence of solvents. Thereafter, in a first stage, a prepolymer of one or more diisocyanates and one or more polyether diols in a molar ratio OH: NCO such as 1: 2 to 1:20, preferably 1: 2, B to 1: 8 prepared. The preparation of such prepolymers is known to the person skilled in the art. In a second stage, optionally in the presence of a catalyst and / or a solvent and / or diluent, the chain extension takes place either with a mixture of known chain extenders and a compound of formula (I) and / or (II) or with these in individual steps , In general, first between 1 and 95 mol% of the remaining isocyanate groups in the prepolymer with a chain extender, preferably 1,4-butanediol, optionally in the presence of a solvent, for. As dimethylformamide, reacted and prepared a solution with still free isocyanate groups. In a third stage, the remaining isocyanate groups, if appropriate with the addition of further solvents and / or diluents, are then reacted with a compound of the formula (I) and / or (II). As the solvent, besides dimethylformamide, dimethylsulfoxide, dimethylacetamide, hexamethylphosphoric triamide, N-methylpyrrolidone, dichloroethane, cyclohexanone and others can be used. Dimethylformamide is preferred. The polyurethanes or polyurethane polyureas obtained are, if appropriate after incorporation of reinforcing materials and / or additives, shaped in the usual manner and then reacted with a quaternizing agent. By incorporation of reinforcing materials anion exchange composites are produced, the

a) 10-90Gew .-% of a reinforcing material, preferably to 70-50Gew .-% of cellulose, and to

b) 90-10 wt .-% of an anion exchanger of the general structure (III), preferably to 30-50Gew .-% consist, wherein

a) and b) to complement each 100%.

The reinforcing materials of cellulose or cellulose derivatives are preferably used as nonwovens or papers. The preparation of the anion exchangers, optionally with incorporation of additives, reinforcing materials, the properties of modifying substances and / or other polymers, by evaporation of the solvent, by coagulation of solutions or by curing of reaction mixtures under shaping, by precipitating in non-solvents. The particular method to be used depends on the desired form of the anion exchanger. For the preparation of membranes, one will generally use a coagulation process and use water as the non-solvent. For the production of granules wild .im best used in a precipitation process. In any case, it is possible to incorporate additives. Such additives are z. As silica gel (Aerosil), barium sulfate, cellulose powder, cellulose fibers, nonwovens, fabrics, paper, threads, etc. A preferred embodiment is to produce anion exchange composites by applying a solution of the polymer of the invention as a layer to a support, a cellulose All coated thereon and impregnated with the solution and this intermediate is then coagulated in a non-solvent. Ee are made in this way particularly dimensionally stable surface support. Furthermore, a direct coating process is possible.

The quarternization of the tertiary amino groups on the side chains is most beneficial to the finished anion exchangers, but can also be done on the solutions or intermediates. Quaternization is best carried out in an organic solvent or mixture, optionally in the presence of water. Particularly suitable solvents are acetonitrile and methanol, and others can be used above. As Quaternislerungsmittel methyl iodide, dimethyl sulfate and ethylene oxide are preferred, others are also possible, for. Ethyl bromide, 1,3-dibromopropane, benzyl bromide, etc. Most preferred is quaternization in a mixture of 10 to 70% by weight of methyl iodide and 90 to 30% by weight of acetonitrile, which may contain up to 5% by weight of water.

Surprisingly, anion exchanges were prepared in this way, which have a high binding stability to DNA fragments with high binding capacity (~ 400 pg / cm ² ) while maintaining the mechanical strength of the polyurethane moldings. According to the known state of the art, a considerable reduction of the strength would be expected even at considerably lower binding capacities. The products according to the invention are suitable for use in molecular-biological detection and separation processes, in particular in transfer processes.

embodiments example 1

a) Preparation of N, N-D! methyl-N ', N'-b! s (hydroxyethyl) propane-1,3-diazine

In a reaction vessel ^r 57,7g Ν, Ν-dimethylaminopropylamine and 80 g of water are added. Subsequently, 48 g of ethylene oxide are added dropwise at 37 to i7 ° C within 2 hours. Thereafter, it is heated for two hours at 100 ⁰ C under reflux with stirring. The water is distilled off at reduced pressure on a rotary evaporator. The residue is distilled quickly in an oil pump vacuum, boiling point of the main fraction at 0.2 mm 120-126 ⁰ C. The structure was confirmed by mass spectrum.

b) Preparation of the prepolymer

300 g of 4,4'-diphenylmethane diisocyanate are erwrirmt to 60 ⁰ C, 0.1 g of benzoyl chloride added and added with stirring and nitrogen 120.2 g of polyethylene glycol 600 such that the temperature does not exceed 75 ⁰ C. Then for 2 hours at 75-8O ⁰ C is stirred.

c) Preparation of the polyurethane solution

In a well vessel, 61 g of the prepolymer are added and heated to 50 ° C with stirring and nitrogen atmosphere. Then 0.05 g of benzoyl chloride and then 9.9 g of 1,4-butanediol are added. Once the temperature of the reaction mixture has reached 80 ° C, it is diluted with 80 g of dimethylformamide. Thereafter, it is stirred at 8O ⁰ C for 30 minutes. Subsequently, 9.8 g of the diamines prepared under a) are added and immediately thereafter a further 80 g of O'methylformamid. The solution is kept at 8O ⁰ C, after 10 minutes more 80g dimethylformamide was added and finally stirred for 2 hours at 8O ⁰ C. There are still added 160 g of dimethylformamide and cooled with stirring to room temperature.

d) Preparation of a membrane

20 g of the solution prepared under c) are thoroughly stirred with 0.3 g Aerosil and 5.0 g barium sulfate and then degassed. The suspension thus obtained is spread by means of a doctor blade on glass plates with a thickness of 0.6 mm. It is then coagulated in deionized water. After coagulation, the membranes are washed for 6x1 hours in deionized water and dried in air.

e) Quaternization of the membrane

In a glass dish, a membrane of 10cm x 10cm is placed and with 50 ml of a 1: 1 mixture of acetonitrile and Overlayered methyl iodide. Then shaken gently with air for one hour at room temperature. After that

the membrane is removed from the solution, briefly dried in air, washed 2 × with 100 ml of methanol and then 6x with 100 ml of deionized water and dried again in air.

DNA binding capacity: 420Mg / cm ² Comparison of Binding Capacity and Stability of Inventive and Comparative Products:

product Bonds Wash 20 ^c C Washing for 1 h Washing 16 h vVaschung24h capacity 20h. at 65 ^° C bai65 ⁰ C 65 ° C ^ g / cm ² ) in bidest. water in bidest. water in 3 x SSC in 10 χ SSC Nylon- membrane 200 190 '14O 100 80 (trade product) polyurethane Membrane with qutrtäremN in the main chain (herge 400 360 90 80 40 represents analog 1 a-e with N-Methyldiethanol- amine as a chain extender product of Example 1 β 420 420 410 380 350

() Preparation of an Anlaonaaustauecherfilms

20 g of the solution prepared under c) are stirred with 0.2 g of Aerosil, degassed and removed by a doctor blade to 0.4 mm films. These films are dried at 100 ^° C. (overnight). Then they are detached from the glass plates, washed as under d) and dried. The dried films are quaternized as in e).

g) Preparation of Anlonenaustauschergranulat

500ml of deionized water are stirred quickly in a beaker. At room temperature, 40 ml of the lower prepared solution are slowly added dropwise. After stirring for 30 minutes, the mixture is allowed to settle, the water is carefully poured off, stirred with 500 ml of deionized water for 10 minutes and this process is repeated 5 more times. After washing, it is suctioned off over a Buchner funnel and washed several times with water. Then it is dried in air.

After drying, the granules are added in 100 ml of a 1: 1 mixture of acetonitrile and methyl iodide and 2 hours

stirred in it. Then it is again filtered with suction, 2x slurried with 200ml of methanol and then 10x with 200ml of water and sucked off. The product is stored moist.

h) Preparation of an anion exchange composite

20 g of the polyurethane solution prepared under c) are spread on a glass plate by means of a doctor blade to form films of 0.4 mm thickness. Filter paper is placed on these films and lightly pressed. After the paper is completely soaked, the composite is deoagulated in deionized water. It is then washed 6 times in deionized water and at the

Air dried. The composite is quaternized as described under e). Example 2

a) Preparation of N, N-dimethyl-N ', N'-β-bis (2-hydroxypropyl) propane-1,3-diamine

In a reaction vessel with intensive condenser and nitrogen inlet, 102 g of Ν, Ν-dimethylaminopropylamine and 116 g of propyl oxide are slowly heated to 40 ° C. while stirring. As soon as the reaction has started, the temperature is optionally kept at 55 ^° C. by external cooling. After the first reaction has subsided, 5 ml of propylene oxide are added and slowly heated with stirring until the temperature is 90 ⁰ C and boiling is no longer detectable. The mixture is then distilled quickly without a column in a vacuum, kp (C, 2Torr) 110-114 ⁰ C. The structure was confirmed by MS.

b) Preparation of the prepolymer analogously to Example 1 b

c) Preparation of the polyurethane solution analogously to Example 1 c

d) Preparation of a membrane

The procedure is essentially as in Example Ί d. However, the amount of Aerosil is increased to 0.5g. The amount of barium sulfate is 7.2g.

e) Quarters

In addition to the quaternization method used in Example 1 e, the following variant is used: ee) A mixture of 55 g of 1-bromoprene and 45 ml of methanol is placed in a glass dish. In this mixture, a membrane of Example 2d is placed 10cm χ 10cm size and shaken with exclusion of air at room temperature for 3 hours. Thereafter, further treatment is carried out as in Example 1 e. In a further variant, instead of the methyl iodide or 1-bromopropane, bromoethane is used.

f) Preparation of an anion exchange film analogous to Example 1 f

g) Preparation of anion exchange granules analogously to Example 1 g

h) Preparation of an anion exchange composite analogously to Example 1 h.

Claims (9)

in the R ^{3 is an} alkylene group having 2 to 18 carbon atoms, an arylene group, an alkylarylene or Arylelkylengruppe or an alkylene-R ⁶ -alkylen-Gruppieiung, R ⁴ and R ^ same or different alkyl groups or R ³ "n ^" ^R 5 together form a saturated or partially unsaturated alkylene heterocyclic "^ R A group having 1 to 2 additional heteroatoms, which may be O, S or NR ⁵ , R ^{6 is} an arylene, oxo, thio,> NR ⁶ or saturated heterocyclic moiety, R ^{8 is an} alkyl radical and X is a halogen atom or a hydroxyl group
mean, from diisocyanates, polyhydroxy compounds and chain extenders, characterized in that one prepares from at least one polyether diol and at least one diisocyanate Vorpolymerisdt, 1 to 95 mol% of the present in the prepolymer isocyanate groups with one or more chain extenders, optionally in solution, the remaining portion from 99 to 5 mol% of the isocyanate groups with a ^r compound of the general formula (I) ^ 2> NR ³ -N-CCr 5 (I) ₁ in the R ¹ and R ^{2 are} identical or different hydroxyalkyl or aminoalkyl groups in which the alkyl radical may optionally be substituted by halogens, and R ³ , R ⁴ and R ^{5 are} as defined above in formula (III), and / or with one Compound of the general formula (II) ^R73 C ^R in which R ¹ , R ² , R ³ , R ⁴ and R ^{5 are} as defined in formula I and R ^{7 represents} a hydrogen atom, a halogen atom or an alkyl group, then reacting the resulting polyurethanes or polyurethane-polyureas, optionally after incorporation of Reinforcement materials and / or additives, usually forms and then reacted with a quaternizing agent. 2. The method according to claim 1, characterized in that the anion exchangers are formed into sheets, preferably to films or membranes. 3. The method according to claim 1, characterized in that in the general formula (I) R ¹ and R ^{2 are} hydroxyalkyl groups, R ^{3 is} a C 2 -C ₆ -alkyl group and R ⁴ and R ^{5 are} methyl or ethyl groups. 4. Process according to Claims 1 and 3, characterized in that in the general formula (I) R ¹ and R ^{2 are} hydroxyethyl or hydroxypropyl groups, R ^{3 is} an ethylene or propylene group and R ⁴ and R ^{5 are} methyl groups. 5. The method according to claim 1, characterized in that methyl iodide is used as the quaternizing agent. 6. The method according to claim 1, characterized in that Anlonenaustauscher composites are prepared by incorporation of reinforcing materials, preferably from cellulose or cellulose derivatives. 7. The method according to claim 6, characterized in that are incorporated as reinforcing materials of cellulose or cellulose derivatives papiore or nonwovens. 8. anion exchange composites, characterized in that they consist of a) 10-90Gew .-% of a reinforcing material and b) 90-10% by weight of an anion exchanger of the general structure (III), where a) and b) each add up to 100% by weight. 9. Anlonenaustauscher composites according to claim 8, characterized in that they consist of a) 70-50Gew .-% of a reinforcing material of cellulose and b) 30-50 wt .-% of an anion exchanger of the general structure (III), wherein a) and b) to each 100Gew .-% complement.