JPS61176608A - Copolymer having nitrophenyl group - Google Patents

Abstract

PURPOSE:A novel copolymer, containing specific repeating units and nitrophenyl groups, and giving a separation membrane capable of separating a liquid mixture containing an aromatic compound effectively by forming the membrane. CONSTITUTION:A novel copolymer, obtained by radically copolymerizing for example an ethylene derivative expressed by formula I (R<1> is H, halogen or lower alkyl; R<2> is H, lower alkyl, phenyl, cyano, halogen OH, etc.) with an ethylene derivative, having OH or NH2, and expressed by formula II (R<3> has the same definition as R<1>; R<4> is alkylene, phenylene, phenylenealkyl or polymethylene; X<1> and X<2> are O or NH; p and q are 0 or 1, provided that p and q are not 0 at the same time), and reacting a nitro-substituted benzoic acid derivative with the resultant copolymer, and having repeating units expressed by formulas III and IV (n is an integer 1-3).

Description

Detailed Description of the Invention [Object of the Invention and Industrial Field of Application] The present invention relates to a novel copolymer having a nitrophenyl group that is useful as a membrane material for a membrane for separating liquid mixtures containing aromatic compounds. .

[Prior art]

The copolymer of the present invention is a new compound that has not been described in any literature, and by forming a film, it can be used as an efficient separation membrane for liquid mixtures containing aromatic compounds.

Pervaporation is known as a typical method for separating liquid mixtures using a non-porous, uniform polymer membrane. This membrane separation method is effective for separating organic liquid mixtures that cannot be separated by ordinary distillation methods, such as azeotropic mixtures, near-boiling point mixtures, structural isomers, and mixtures containing substances that are easily denatured by heat.

The separation of such liquid mixtures containing aromatic compounds, especially liquid mixtures of aromatic nuclear substitution isomers, poses many industrial problems.

For example, the separation of xylene isomers and ethylbenzene obtained as the C8@ fraction of petroleum refining involves a series of methods that combine highly precise distillation, fractional crystallization, and chemical reactions, or extraction and separation by specifically complexing the target substance. The development of an efficient separation method is strongly desired since it requires repeated extremely complicated operations. Attempts have also been made to apply the above-mentioned pervaporation method to this separation.As separation membranes, crystalline polyethylene membranes, cellulose derivative membranes, and cyclodextrin-containing polymer membranes are known, but the former two have a high selectivity. In addition, the latter has extremely poor membrane permeability and is difficult to put into practical use.

Recently, a method has been proposed in which a Werner complex that specifically forms an clathrate compound for these nuclear substitution isomers is supported in a membrane to improve the separation ability, but the conditions when creating the membrane, Not only is the operation complicated, but the transparency is low, making it unsuitable for practical use.

As described above, to date, no polymer membrane has been known that can efficiently separate liquid mixtures containing aromatic compounds, particularly liquid mixtures of nuclear substitution isomers.

The present invention provides a polymer separation membrane material that can efficiently separate a liquid mixture containing an aromatic compound from a liquid mixture containing an aromatic compound that is an unsubstituted or electron-donating nuclear substitution isomer. By doing so, the drawbacks of the above-mentioned polymer membranes can be solved.

[Detailed description of the invention]

It is generally known that a charge transfer complex is formed between an electron donating compound and an electron accepting compound. This complex formation reflects the electronic state of the molecule, and even if the molecular forms are somewhat similar, the complex formation ability often differs (see β Example 14). The present invention focuses on this point and provides a copolymer having a novel nitrophenyl group that can be used as a separation membrane material that realizes efficient membrane separation by cleverly utilizing the formation of intermolecular charge transfer complexes. It is.

A copolymer consisting of a repeating unit represented by +CH2C÷ □(I) 几2 and a repeating unit narrowed by the general formula [wherein 几1
and R3 is a hydrogen atom, a rogen atom or a lower alkyl group, 2 is a hydrogen atom, a lower alkyl group, a substituted or unsubstituted phenyl group, a cyano group, ) a rogen atom, a hydroxyl group,
an alkoxycarbonyl group or a hydroxyalkyloxycarbonyl group, R1' is an alkylene group, a phenylene group,
Phenylene alkyl group or polymethyleneph group, Xl
and X2 represents 10- or -N) i -i, p and q
represents an integer of O or 1, and n represents an integer of 1 to 3. ] and a copolymer consisting of a repeating unit represented by the general formula (D), a repeating unit represented by the above general formula (■), and a repeating unit represented by the following general formula (wherein
, Xl, X2, p and q are the same as above).

These copolymers of the present invention include, for example, an ethylene derivative represented by the general formula and an ethylene derivative having a hydroxyl group or an amino group represented by the general formula (during polymerization, it may be protected with an acetyl group or the like as necessary). A copolymer having a hydroxyl group or an amino group that can be produced by radical copolymerization with (see reference side)
can be obtained by reacting with a nitro-substituted benzoic acid derivative.

Ethylene derivatives represented by the general formula (transformation) include ethylene, flopylene, styrene, α-methylstyrene, p
-chlorostyrene, p-bromostyrene, acrylic acid,
Methyl acrylate, ethyl acrylate, acrylic acid 2-
Examples include hydroxyethyl, methacrylic acid, methyl methacrylate, ethyl methacrylate, 2-hydroxyethyl methacrylate, 2-hydroxypropyl methacrylate, acrylonitrile, methacrylonitrile, vinyl chloride, vinylidene fluoride, methyl α-chloroacrylate, etc. can do.

In addition, examples of ethylene derivatives having a hydroxyl group or an amino group represented by the general formula (b) include 2-hydroxyethyl acrylate, 2-hydroxyethyl methacrylate, 3-hydroxypropyl acrylate, 2-hydroxypropyl methacrylate, and vinyl alcohol. (hydrolyzed after copolymerization in the form of vinyl acetate), allyl alcohol, 2-hydroxyethyl α-chloroacrylate, N-(2-hydroxyethyl)acrylamide, p-hydroxystyrene,
Examples include p-aminostyrene, allylamine, and N-methylolacrylamide.

The nitro-substituted benzoic acid derivatives used in the above nitrophenyl group introduction reaction include Q-, m- or p-
Nitrobenzoic acid chloride, 2.4-Froic acid chloride, 2,
4.6-) Linitrobenzoic acid chloride, p-nitrobenzoic acid fluoride, m-nitrobenzoic acid bromide, 3.4
-Methyl dinitrobenzoate and the like can be exemplified.

The reaction is preferably carried out in a solvent, and examples of the solvent include N,N-dimethylformamide, N-methylpyrrolidone, tetrahydrofuran, dioxane, pyridine, chloroform, chlorobenzene, dichlorobenzene, etc. I can do it.

Further, in the reaction, it is preferable to coexist amines such as triethylamine and pyridine in order to make the reaction proceed smoothly.

In addition, in this reaction, the hydroxyl group or amino group t-
By completely nitrobenzoylating the hydroxyl groups or amine groups in the copolymer (i), a copolymer consisting of repeating units represented by the above general formulas (1) and (2) can be obtained. Further, by controlling the rate of introduction of nitrophenyl groups by the above-mentioned nitrobenzoylation, it is possible to obtain a copolymer containing the third repeating unit Kanakura represented by the general formula (2).

This rate of introduction can be controlled by changing the weight ratio of the hydroxyl group or amine group to the nitro-substituted benzoic acid derivative in the combined raw materials.

This introduction rate is 0.1 as a mole percentage of the combined middle-aged child.
% or more, p, io1 or more is preferable for use as a separation membrane material. Further, from the viewpoint of mechanical strength of the copolymer film, it is desirable that the molecular weight of the copolymer is 10,000 or more.

[Effects of the Invention] The copolymer of the present invention can be formed into a film by, for example, a casting method after being dissolved in a solvent. The resulting polymer membrane has sufficient mechanical strength as a separation membrane. In addition, it is useful as a separation membrane for liquid mixtures containing aromatic compounds, demonstrating selectivity and permeability exceeding those of the prior art in the separation of xylene isomers, for example (see Reference Examples 11 to 1).

Hereinafter, the present invention will be explained in more detail with reference to Examples and Reference Examples.

Reference Example 1 2-hydroxyethyl acrylate (HEA) and 2-hydroxyethyl methacrylate (HEMA) were prepared and the molar composition was HnA/)iEMA = 0.7/0.3
, N,N-dimethylformamide (1) MP) 93.83d as a diluent and polymerization 2,2'-azobisisobutyronitrile (AIB
After 0.0985 g of N) was placed in an ampoule and thoroughly degassed according to a conventional method, the tube was sealed under high vacuum (10 mmHg or less). This was stirred at 60C for 1.0 hour to carry out a polymerization reaction.

f(EA) with a yield of 22.5% in diethyl ether
-) An IBMA copolymer was obtained.

Reference Examples 2 to 7 HhA-HEMk copolymers were synthesized in the same manner as in Reference Example 1 by changing the charged compositions of HEA and IDMA.

The results are shown in Table 1.

AIBN Iso [=5X10-”mOl/A'Reference example 8-1
An iEA-St copolymer was synthesized in the same manner as in Example 1 except that styrene (St) was used as a monomer for IEMA. The results are shown in Table 2.

Table 2. Synthesis result of HEA-8t copolymer AIBN1 degree=
5 X 10-'' mol/1 Example 1 HEA-HEMA copolymer 6-51 obtained in Reference Example 1
Dissolve in gtDMF6-5l and add 6.60 It/
of pyridine was added and cooled to OC. While vigorously stirring this solution, 12.48 g of 3,5-dinitrobenzoic acid chloride was added.
20i1 of a DMF solution containing g was added dropwise and reacted for 20 hours. After the reaction was completed, the mixed solution was poured into a large amount of pure water to precipitate heavy metals, which were then filtered off.

This was dissolved again in DMF and the solution was added dropwise to diethyl ether to purify a copolymer having 3,5-dinitrophenyl groups in the side chain. The yield of the copolymer after drying was 45.5%, ip, IR spec-1'
As a result of the -1 Torr measurement, absorption based on a phenyl group was observed at 31000IF, 160-, and an aromatic nitro group was observed at 1540cs*, 1345m. According to the elemental analysis results, the introduction rate of 1i113,5-dinitrophenyl group was 60.7%. Furthermore, the large weight average molecular weight determined by GPC is 9.91 x 10 in terms of polystyrene.
Ivy.

Examples 2-10 HBA-HEMA copolymers of Reference Examples 2-6 and Reference Example 8
A 3,5-dinitrophenyl group was introduced into the side chain of the HBA-St copolymer of ˜1O by the same method. The introduction rate is the ratio of acid chloride to copolymer side chain hydroxyl group ((,'0
It can be controlled by changing CI)/α■]. The results are shown in Table 3.

Example 11 Using the HE human-St copolymer of Example 8 and 3,4-dinito bbenzoic acid chloride, (CO
Cl)/(OH): Obtains a copolymer with 1, O and 3,4-dinitrophenyl group in the side chain. The introduction rate of 3゜4-dinitrophenyl group was 53.0, and the yield was 40.1.
% was rare.

Reference Example 11 A 5% by weight tetrahydrofuran solution of the copolymer of Example 9 was cast onto a 251 Teflon plate, and the solvent was removed by heating to obtain a transparent and uniform polymer film. The thickness of this film was 867 an.

The obtained large film was inserted into a stainless steel cell for pervaporation method (pervaporation cell), and the m
Permeation measurements were carried out using a pervaporation method using a -xylene 10-xylene mixture as a feed liquid.

The results are shown in Table 4.

However, α. =(permeate composition ratio)/(supply liquid composition ratio) Reference Example 12 A polymer film was formed using the copolymer of Example 1 in the same manner as Reference Example 11. The membrane thickness was 59 Ixn and the permeation of O-xylene/p-xylene mixture was measured using the pervaporation method using this membrane, P = 441 $,
1-v-, a',, = I, shout and rock nine.

Reference example 13 Same as Reference Example 11 except that the film thickness was 52 ropes.

The permeation of m-xylene/p-xylene mixture was measured using the method P = 8. -Hoe 11F, α;= +, CI
I got 6 in 9.

Reference Example 14 A polymer membrane was prepared from the copolymer of Example 2 in the same manner as Examples 1 to 4. The film thickness was 12011 m. Using this membrane, the permeation of a benzene/cyclosan mixture was measured using the pervaporation method. As a result, 53.1/46.
At a feed liquid composition ratio of 9, P = 10.3 = g/
It was 60 m-hr. Also, the permeate composition is benzene 100
% jb), only benzene was selectively permeated.

The charge transfer mutual O formation constant between ethyl 3,5-dinitrobenzoate and xylene isomers, which have a structure very similar to Reference Example 15, is 0.440 for p-unit, 〇-unit, and m-unit, respectively (
J/mol), 0.528 (l/mol), 0
．． A value of 580()/mo 1 ) was obtained. This means that
This shows that the affinity between xylene isomers and copolymers increases in this order.

Claims (2)

[Claims] (1) A copolymer consisting of a repeating unit represented by the general formula ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ and a repeating unit represented by the general formula ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ (In the formula, R^
1 and R^3 are hydrogen atom, halogen atom, or lower alkyl group, R^2 is hydrogen atom, lower alkyl group, substituted or unsubstituted phenyl group, cyano group, halogen atom, hydroxyl group, alkoxycarbonyl group, or hydroxyalkyloxy The carbonyl group, R^4, is an alkylene group, phenylene group, phenylene alkyl group or polymethylene group,
X^1 and X^2 represent -O- or -NH-, p and q represent an integer of 0 or 1, and n represents an integer of 1 to 3. ). (2) Repeating units represented by the general formula ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ and repeating units represented by the general formula ▲ There are mathematical formulas, chemical formulas, tables, etc. There is a copolymer consisting of repeating units represented by ▼ (in the formula, R^
1, R^2, R^3, R^4, X^1, X^2, p, q
and n are the same as above. ).