DE2343850A1 - PROCESS FOR MANUFACTURING HYDROXY ALKYL METHACRYLATE GELS AND THEIR USE FOR GAS OR LIQUID CHROMATOGRAPHY - Google Patents

Description

234385Q

August 30, 1973

Ceskoslovenska akadetnie ved, Praha (CSSR)

Process for the preparation of hydroxyalkyl methacrylate gels and their use for gas or liquid

matography

The use of organic sorbents based on macropolar copolymers of divinylbenzene with ethylvinylbenzene and styrene in grass chromatography was 1966 from Hollis (Anal. Ghem. 38 (1966) 309). Ever since then organic sorbents when analyzed by means of gas-solid adsorption chromatography used. Proven sorbents of this type are currently, for example, "Porapak" from Pa. Waters Associates, Inc., "Ghromsorb 101-105" by Pa. John Manville and "Synachrome" of the Research Institute for Synthetic Resins and Lacquers (VUSPL, Pardubice, GSSH) of various origins, which are in different Modifications and, in particular, the modification prepared by silylation are available.

When comparing the polarity of these sorbents with the 233- (S 8068) HoHe

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Polarity of the liquid phases using the Brownian retention fractions (Brown I .: J. Chromatog. JK) (1963) 284) one recognizes that they are similar to the completely non-polar phases. For example, "Porapak Q", a copolymer of ethylvinylbenzene with divinylbenzene, is similar in polarity to squalene, and "Porapak P", a copolymer of ethylvinylbenzene with styrene and divinylbenzene, comes in terms of polarity Methylphenyl silicone oils close. The modified macroporous Vinylbenzene copolymers ("Porapak QS" and "PS") are similar to the somewhat more polar liquid phases such as silicone oils and silicone elastomers. Nevertheless, the polarity range of the macroporous styrene-divinylbenzene copolymers is very small and cannot be significantly expanded even by modifying them. It follows that the accessible sorbents this type is only suitable for separating alkanes or alkynes, but already for separating polar substances are less suitable.

The unmodified hydroxyalkyl methacrylate gels can can be used directly for some separations, especially for the analysis of gaseous mixtures. The modification of the gels for gas or liquid chromatography can be of the present invention by surface transformation of the internal structure by making the stationary Phase chemically fixed by means of covalent bonds. The hydroxyalkyl methacrylate gels already have a number of Applications found in chromatography (H. Kubin, P. Spaeek, R. Chromeceki Coll, Czech. Chew. Commun. ji2 (1967) 3881; J. Coupek, M. Krivakova, S. Pokorny; IUPAC Int. Symposium on Liacromoleeules, Helsinki 1972} J. Coupek, J. Turkova, 0. Hubalkova, H. Krivakovaι Czechoslovak patent application PV 2106-72).

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According to the present invention are now macroporous hydroxyalkyl methacrylate copolymers or by chemical Conversion of modified hydroxyalkyl methacrylate copolymers used for gas and liquid chromatography. These Copolymers have a function of the proportion of the monomers and the conditions of the suspension polymerization (which are changeable within wide limits) changeable surface and polarity, whereby the retention volume of the chromatographed Substances (e.g. in gas chromatography) and thus also the duration of the analysis can be influenced. the The chemical structure of the hydroxyalkyl methacrylate copolymers also makes it possible through a simple polymer-analogous conversion the polarity of the sorbents, which according to Rohrschneider (Rohrschneider L.i J. Chromatoggr. 2 £ (1966) 6) by the Retention indices of benzene, ethanol, methyl ethyl ketone, Nitromethane and pyridine is defined within wide limits to modify.

To produce the priaär ^oV! Sorbents can be obtained by copolymerizing hydroxyalkyl acrylates, hydroxyalkyl methacrylates, oligo- and polyethylene glycol acrylates, oligo- and polyethylene glycol methacrylates, acrylonitrile and methacrylonitrile with alkyl diacrylates, alkyl dimethacrylates, oligo- and polyethylene glycol dimethacrylates and divinylbenzene. The polarity of these macroporous copolymers can be determined by polymer-analogous transformations of the surface, such as, for example, 3. by stearoylation, silylation, hydroxyethylation or gyanethylation, whereby the original properties of the copolymers, such as mechanical strength, macroporosity, thermal resistance, etc., are retained or even improved. So z.Ji. Cyanethylation improves the thermal stability of the ethylene glycol methacrylate copolyesters.

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? 343S50

The use according to the invention of these sorbents in chromatography improves and in particular accelerates the separation of branched hydrocarbons, olefins, alcohols, aldehydes and ketones, chlorinated hydrocarbons and some volatile inorganic compounds in particular. These sorbents can also be used for the separation of aromatic hydrocarbons. The small retention volume of -'fässer also enables the gas chromatographic analysis of aqueous solutions of organic substances, which can be carried out in the manner of gas-solid distribution chromatography. The Äthylenglykolmethacrylat-sorbents have a high efficacy, which is sufficient (for example, 766 theoretical plates per column length Lüter) are completely heat resistant up to 25O ⁰ G for most gas chromatographic analyzes.

The chemical fixation of the stationary phase for the purpose of liquid chromatography extends the range of applications the solvents considerably, as those that occur when the stationary phase is washed out with eluent No complications. This of course also increases the scope of the analyzes that can be analyzed by means of liquid chromatography Systems, because by a suitable choice of the phase one can not only improve the separation efficiency of the chromatographic columns, but especially improve their resolving power. The application of hydroxyalkyl methacrylate-u-ele in liquid chromatography comes primarily in the analysis of Natural substances such as lipoids and steroids into consideration, but also when analyzing non-natural mixtures of organic compounds such as petrochemicals Products, for products of dye chemistry and pharmaceuticals, especially if the mixture to be analyzed is thermally un-

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contains permanent components.

The following are examples to illustrate the invention.

example 1

2.4772 g of a macroporous 2-hydroxyethyl methacrylate copolymer crosslinked with 90% by weight of ethylene dimethacrylate and having a specific surface area of 209.05 m / g were used to fill a glass column 114 cm long and 0.32 cm internal diameter for gas chromatography. The gas chromatographic separation of an aqueous solution of the polar compounds methanol, ethanol, acetone, propanol and ethyl acetate at a column temperature of 175 ⁰ O and a nitrogen flow rate of 34.4 ml / min was successfully carried out on this column with 513 theoretical plates per meter of column length . The duration of the analysis was 5.5 minutes. The pipe cutter indices of the sorbent ^{1 used were} j χ = 0.28; y = 1.29} ζ = 0.82 and u = 1.96} s was not determined.

Example 2

^{4.1522 g of a sorbent 1} produced by copolymerization of 2-hydroxyethyl methacrylate with 50% by weight of ethylene dimethacrylate were used to fill a glass column 110.1 cm in length and 0.32 cm in internal diameter. The successful chromatographic separation of the G ^ -C.-alcohol series at a column temperature of 175 ⁰ C and a carrier gas Strömungsges-chwindigkeit of 37.3 ml / min was completed within 3 minutes. For the column with 764 theoretical plates per meter of column length

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was no "tailing" of the chromatographic "Waves" observed. The means of the Eohrsehneider indices defined polarity of the sorbent * corresponded to ι = 0.87 | y = 2.21i z = 1.91 and u = 2.55; s was not determined.

Example 3

A column 1 m long and 0.32 cm inside diameter was filled with a macroporous perpolymer of acrylonitrile, 2-hydroxyethyl methacrylate and ethylene dimethacrylate (weight ratio of the monomers 2 3: 5) with a specific surface area of 95.3 m / g. At a column ^{temperature of 175 °} C. and a flow rate of the nitrogen carrier gas of 36 ml / min, a mixture of the polar compounds methanol, ethanol, acetone, propanol and ethyl acetate was successfully separated on this filling. The duration of the analysis was 6 minutes.

Example 4

Bin from 2-hydroxyethyl methacrylate and 60 wt -. ^C /> divinylbenzene copolymer produced with a specific surface area of 145.7 m / g and a particle size of 160 to 200 μ was used as chromatographic adsorbent for the separation of the hydrocarbons to Pent, hexane, cyclohexane, Benzene, heptane and octane are used. At a column temperature of 175 ⁰ O and a flow rate of the nitrogen carrier gas of 38 ml / min, the complete analysis was successfully completed within 4 minutes.

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Example 5

A macroporous copolymer produced from 2-hydroxyethyl methacrylate with 50% by weight crosslinking agent was modified by stearoylation. Before the reaction, 5-8 parts by weight of the copolymer were swollen in 50 parts by weight of anhydrous benzene-pyridine mixture (1: 1), then 8.6 parts by weight of stearoyl chloride were added and the mixture was heated at 50 ° C. for 45 minutes. Was then filtered off with suction, the product is extracted with ethanol and vacuum drying cabinet at 78 ⁰ G and 0.05 Torr dried. According to Haefe's carbon elemental analysis, the molar conversion was 20.13 mol, based on the 2-hydroxyethyl methacrylate contained in the copolymer. The sorbent modified in this way was used for the separation of branched hydrocarbons. The pipe cutter indices of this sorbent were; χ = 1.4-1 »y = 2.65; ζ = 2.20 and u = 3.1 »s was not determined.

Example 6

A modified sorbent was made by treating ethylene glycol methacrylate copolymers with trialkylchlorosilanes or hexaalkyldisilazanes. In the present case 5 parts by weight of the prepared with 90 wt. -I "crosslinking agent copolymer in 50 parts by weight of anhydrous ither-pyridine mixture (4 'x 1) were suspended, then were Hühren drop meadow successively 5 parts by weight of trimethylchlorosilane in 20 parts by weight of anhydrous ether was added and then the mixture was stirred for a further 1 hour at room temperature. The product was then filtered off, washed with ether, water and ethanol and dried to constant weight in vacuo. The sorbent prepared in this way was successfully used for separation

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the C .jG. -Paraffins used at 50 ⁰ G and a nitrogen flow rate of 40 ml / min.

Example 7

Oorbens used to separate branched hydrocarbons and polar hydrocarbons containing a heteroatom was obtained by hydroxyethylation of a macroporous 2-hydroxyethylniethacrylate copolymer. 5 parts by weight of the 2-hydroxyethyl methacrylate and 39 wt .- '/ i crosslinking agent prepared Oopolymer were in 100 parts by weight of 30 percent. Sodium hydroxide swelled. The excess alkali was then separated off, 5 parts by weight of ethylene chlorohydrin were added to the swollen copolymer, and the mixture was left at room temperature for 3 hours with intermittent stirring. Then, the product with dilute acid and then / ater and washed with ¥ 'forr dried in a vacuum oven at 78 ⁰ C and 0.02.

Example 8

A substantially polar sorbent was obtained from a polymer of 2-hydroxyethyl methacrylate and 39% by weight crosslinking agent by means of polymer-analogous conversion of the surface by cyanoethylation. First, 7 parts by weight of the macroporous copolymer with a particle size of 200 μ in 50, weight st parts 0.5 πι NaOH were swollen, then 7 parts by weight of acrylonitrile were added and the mixture was stirred for 4 hours at room temperature. Then, the product was filtered off, extracted with ethanol and dried under high vacuum at 78 ⁰ G. This sorbent has been used with success for the gas chromatographic separation of polar compounds.

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Example 9

The sorbent prepared by stearoylation according to Example 5 was filled into a 1500 mm long column made of stainless steel with an internal diameter of 3 mm. On this filling, a liquid chromatography of a glyceride mixture was carried out using ethanol as the solvent.

Example 10

üin by copolymerization of diethylene glycol monoethacrylate macroporous prepared with 40% by weight of ethylene dimethacrylate Gel was activated by cyanoethylation analogously to Example 8. The modified sorbent obtained stood out by a higher polarity than the corresponding prepared by polymerization of 2-hydroxyethyl methacrylate and similarly modified gel.

Example 11

A macroporous gel prepared by copolymerization of 2-hydroxyethyl methacrylate with 60% by weight of divinylbenzene was used for the gas chromatography of aromatic hydrocarbons, which differed by the substitution on the core.

Example 12

A copolymerization of 10 parts by weight of acrylonitrile, 50 parts by weight of 2-hydroxyethyl methacrylate and 40 parts by weight of ethylene dimethacrylate prepared macroporous Copolymer with a specific surface area of 181.9 m / g

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became in the form of grains of 100 to 200 µm in grain size used to fill a gas chromatographic column. A mixture of ethanol, ethyl acetate, Successful separation of n-propanol and tert-butanol.

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Claims (5)

Claims VjJ Process for the production of hydroxyalkyl methacrylate gels, especially for 3 gas or liquid achromatography, characterized in that macroporous copolymers are produced by heterogeneous suspension copolymerization of polar monovinyl monomers such as hydroxyalkyl acrylates, hydroxyalkyl methacrylates, oligo- or polyacrylate methacrylates, oligo- or acrylic methacrylates, oligo- or acrylate-methacrylates, oligo- or acrylate-ethylene glycols Acrylonitrile or methacrylonitrile; with divinyl or polyvinyl comonomers capable of copolymerization with the polar ionovinyl monomers, such as aerylate or methacrylate esters of polyfunctional alcohols which contain two or more acrylate or methacrylate groups in the molecule, generated and optionally modified. 2. The method according to claim 1, characterized in that an alkylation, acylation, silylation, Provides hydroxyethylation or cyanoethylation as well as the reaction with isocyanates or halogenation, a change in the polarity of the starting material occurs. 3. The method according to claim 2, characterized in that the alkylation is carried out with chlorides of higher fatty acids such as stearic or palmitic acid. 4. Use of the gels according to claim 1 for the rapid analysis of aqueous solutions of branched organic compounds Hydrocarbons and polar compounds by gas or liquid chromatography. 4098 1 1/1102 5. Use according to d * aa. Claim 4, characterized in that that one for gas or liquid chromatography mixtures of organic compounds or their aqueous solutions begins. 409811/110 2