DE1215124B - Process for the production of diaethylaminoethyl cellulose ethers which can be used as anion exchangers - Google Patents

Description

Process for the preparation of usable as anion exchangers Diethylaminoethylcellulose ethers It is known that anion exchangers can be etherified of o; cellulose powder with 2-chloro-N, N-diethylethylamine (S o b e r s and P e t e rsohn, J. Am. Chem. Soc., 1954, 76, 1711/1712, ibid.

1956, 78 (1), 751-755, Sobers et al, J. Am. Chem.

Soc. 1956, 78 (1), 756 to 763). This diethylaminoethyl cellulose, which is also known as "DEAE cellulose" was found as an ion exchange adsorbent for proteins and proteinaceous substances, e.g. B. enzymes, application, since relatively large Amounts of protein adsorbed on it and made from "DEAE cellulose" under mild conditions can be eluted. o ¢ -Cellulose appeared particularly promising to the above authors because of their hydrophilic character and their large surface area, the latter being Property is important for determining the adsorption capacity of the modified DEAE cellulose. The other factor affecting the adsorption capacity of DEAE cellulose Affected is the number of active groups introduced into the cellulose can be; However, experiments show that the cellulose is all the more gelatinous and the more diethylaminoethyl groups are present, so that in in practice a limit on the number of ion-exchanging groups that can be introduced exists, although the diethylaminoethylation may still be incomplete.

When performing ion exchange processes in an economical In general, the scale will be the use of a continuous before a discontinuous one Method preferred, and in the case of »DEAE-Cellulose« too, a substance is therefore which is suitable for a column process is desirable. Thus, ion exchangers should which are suitable for economical work, as far as possible the following properties possess: 1. They should be porous, so that a large number of active groups for the liquid to be treated is available; 2. They should be sufficiently open Represent the structure to ensure a good flow of the liquid through the column; 3. They should have an approximately uniform particle size so that the Material not through various sedimentations while filling the column secretes. A uniform particle size also contributes to the formation of channels to prevent and maintain regular flow throughout the cross-section of the column; 4th the particles should not clump together or form aggregates so that the column is filled can be backwashed and fluidized, for example to remove foreign bodies; 5. The particles of the material should be in aqueous salt solutions and mildly acidic and alkaline reagents are sufficiently hard that they Elution and regeneration keep their physical form and do not stick together or settle down to such an extent that the flow rate is no longer can be adhered to.

»DEAE-Cellulose«, which was produced according to known methods, generally possesses the former of these properties, but it tends because of them fine, slightly gelatinous powdery form to clump easily is not easily backwashable and does not guarantee a satisfactory flow rate. Also, after a series of regenerations, it becomes too gelatinous to continue in to find a column use.

In the attempts to produce an improved ion exchange substance of the »DEAE type« made from celluloses different origins were found that above all a certain type of cellulose is used to produce a »DEAE« (- cellulose exchange material suitable, which is particularly satisfactory for economical work in columns is and in many respects the above-mentioned requirements for an ideal ion exchange material comes close. The inventive method for producing as an anion exchanger usable diethylaminoethylcellulose ethers by alkalizing cellulose and subsequent etherification with diethylaminoethyl halide is characterized by that the process with a regenerated cellulose with a non-oriented structure performs. This non-oriented structure is of the more oriented structure naturally occurring celluloses or celluloses regenerated by stretching or tensioning, z. B. stretched viscose rayon, different.

Unoriented cellulose is best made using the viscose process by very slow extrusion or spinning with the lowest possible tension manufactured. This procedure differs from the under voltage resp. Stretching performed viscose rayon processes in which the manufactured Fibers contain a substantial proportion of more highly oriented cellulose. One Particularly suitable form of cellulose for the production of »DEAE <(- cellulose anion exchangers is made by Courtaulds Ltd., Coventry, under the name "Rayon Monofil" ÖR put on the market.

Unoriented, regenerated cellulose, which is the starting material of the ion exchange material which can be produced according to the invention can be higher oriented, regenerated cellulose or from natural cellulose by a Set of physical methods that allow the determination of the infrared absorption spectrum and the measurement of birefringence. They don't oriented cellulose shows less sharply defined infrared absorption maxima and minima and gives lower birefringence values than the more highly oriented Cellulose.

The cellulose can be in any suitable form, however will Particle shape preferred.

The cellulose, which is initially in the form of rods or threads, is preferred first in particles of suitable size for use in an ion exchange column processed before the ion exchange group is introduced. The particles can are of any suitable size, but are preferably no greater than 1.68 mm In diameter. It has been found that particles are between 0.295 and 1.00 mm in diameter are particularly satisfactory.

The cellulose "rayon monofilament" (0 is normally supplied as a 1000 to 60,000 denier single fiber, and for the present invention is particularly useful as a 25,000 denier single fiber. This substance can be converted into particles of suitable size by any suitable method be e.g. B. by cutting into small particles about 0.64 cm in length, and then Rolling into particles of any shape and size.

The cellulose particles are then made in a manner known per se etherified with diethylamino groups by first reacting an alkali hydroxide be, whereby alkali cellulose is formed, which then with a diethylaminoäthylhalo- genius, preferably in the form of a hydrohalide. It is special favorable to use sodium hydroxide solution and diethylaminoethyl chloride.

The ion exchange material which can be produced according to the invention consists generally from a loose structure, easily substituted on the "DEAE groups" and permeated by the molecules of the substances to be adsorbed. Thus offer the particles of this substance generally form part of the liquid to be treated represent a large number of active groups.

The ion exchange material can have exchange capacities of about 0.1 to about 2.0 meq / g (dry weight) can be produced. Particularly valuable is a material with an exchange capacity of 0.3 to 1.6 meq / g (dry weight).

With an exchange capacity of significantly more than 2.0 mVal / g, there is a tendency also the material that can be produced according to the invention as well as the known "DEAE cellulose" to gel or become water-soluble.

A suitable choice of the particle size can ensure good flow of the Liquid can be easily maintained by the column, and in particular can better flow rates can be obtained than with the previously available "DEAE celluloses".

The ion exchange material which can be produced according to the invention can be used in Particles similar to those produced by common ion exchange resins, especially in a form that can be backwashed and upwardly flowing through which air can be blown like a conventional ion exchange resin.

The materials that can be produced according to the invention generally have good stability and, in particular, show improved stability compared to Alkali and they keep their respective shape well. You can thus often be regenerated , their properties generally changing little, although one Change in volume is observed.

The flow rate, however, generally remains fairly constant.

Ion exchange materials, according to the invention from particles with 0.076 to 0.251 mm in diameter have a size slightly higher exchange capacity than materials of the preferred particle size (from Particles with a diameter of 0.295 to 1.00 mm), but this is increased capacity not proportional to the increased surface area, and the flow rate is easily excessively reduced when operated on a large scale.

The ion exchange materials which can be produced according to the invention can can be used to adsorb many substances. Although in general they always do can be used for the purposes for which the well-known »DEAE celluloses« were applied, e.g. B. for the separation and purification of proteins etc., it has been found that the new material is particularly valuable for cleaning and / or concentrating Fungal a-amylase is. The new materials can also be used for cleaning and / or concentration of, for example, poliomyelitis virus and vitamin Bl2 acid (through adsorption) and vitamin B12 (through adsorption of impurities, - while the vitamin through the column is running), as well as for demineralizing water.

The following example is intended to explain the invention: Example production of the ion exchange material Approx. 2 kg of individual rayon fibers with one denier of 25,000, first quality "Rayon Monofil" (§ '(manufacturer Courtaulds Limited, Coventry), were hand cut into pieces about 1/4 inch in length and then through a Laboratory hammer mill without sieves happened. The material was sieved and yielded a fraction of 1.058 kg which passed a sieve with a mesh size of 1.00 mm and was retained by a sieve with a mesh size of 0.295 mm. These Fraction was at 11 "C for 1 hour with 5.3 l of a 6 solution of sodium hydroxide mixed. A solution of 1.058 kg of diethyl chloroethylamine hydrochloride in 1.6 l of water was added and mixed continuously for 35 minutes at 85 "C. The mixture was cooled to room temperature and added 2.5 liters of concentrated hydrochloric acid acidified. The ion exchange material was isolated by filtration, with 12 1 tap water, 5.3 1 1 n-sodium hydroxide solution and then washed with tap water, until the wash waters were almost neutral. The exchange capacity of the received Product is 0.7 meq / g. The valuable properties of the ion exchange material are shown below using the example of the concentration of the enzyme mushroom ol amylase from a culture fluid of Aspergillus oryzae by adsorption. For the procedure No protection is sought for the work-up of ol-amylase in the context of the invention.

The material prepared according to the previous example was used as a suspension placed in water in a glass column (3.5 m high and 5.08 cm in diameter) and made a 2.1 m high bed with a volume of about 4.21. This bed was made with 8.4 1 0.1 molar phosphate solution, pH 6.6, buffered, with 8.41 / hour. downward let flow through. 75 1 of an a-amylase-containing culture liquid from Aspergillus oryzae with a dextrin activity of 14.0 units / ml corresponding to 1,050,000 units Total activity (1 unit is the amount of enzyme that makes 1 g of starch per hour is broken down to dextrin) were adjusted to pH 6.6 with acetic acid by Filtered a sterilized filter paper, and using it down the column a speed of 4.21 / hour. guided; then were crowding 4.2 l of water at a rate of 4.21 / hour. passed through the column. the Analysis of the column effluent showed 1700 units of total dextrin activity, with 1 048 300 units were adsorbed, corresponding to a 99.80 /, igen effectiveness. The adsorbed amylase was eluted (downward flowing) with 4.2 1 of a 0.8 molar acetate / 0.8 molar sodium chloride buffer solution of pH 4.7 isolated and then washed with 4.2 l of water at a rate of 2.1 l / hour. A 7 liter portion of the eluate contains 992,200 units of total dextrin activity accordingly a 94.60% potency and a 10% concentration of the original Solution.

The column was then washed (descending) with 8.41 10 n sodium carbonate solution containing 2.5% sodium chloride, regenerated with Washed with water and, as previously described, buffered again with phosphate.

Claims (4)

Claims: 1. Process for the production of as an anion exchanger usable diethylaminoethylcellulose ethers by alkalizing cellulose and subsequent etherification with a diethylaminoethyl halide, thereby k e n nz E i c h n e t that one cannot use the process with a regenerated cellulose oriented structure as the starting material. 2. The method according to claim 1, characterized in that the Process with a cellulose in the form of particles carried out by crushing from rod or fibrous regenerated cellulose. 3. The method according to claim 2, characterized in that the Process with cellulose particles carried out from a fiber of 1000 to 60 000 denier have been produced. 4. The method according to claim 2 and 3, characterized in that one carries out the process with cellulose particles no larger than 1.68 mm in Diameters are, and preferably a size between 0.295 and 1.00 mm in diameter to have. Publications taken into consideration: Kurt Götze, Man-Made Fibers nach dem Viskoseverfahren, 2nd edition, 1951, pp. 462 and 463.