EP0775162A1

EP0775162A1 - Mesomorphic complexes of polyelectrolytes and surfactants, process for producing the same and films, foils, fibres, moulded bodies and coatings made thereof

Info

Publication number: EP0775162A1
Application number: EP95929055A
Authority: EP
Inventors: Axel Kistenmacher; Markus Antonietti; Jürgen CONRAD
Original assignee: BASF SE
Current assignee: BASF SE
Priority date: 1994-08-12
Filing date: 1995-08-02
Publication date: 1997-05-28
Also published as: US5863956A; DE4428641A1; WO1996005235A1; JPH10504586A

Abstract

Mesomorphic complexes consist of anionic polyelectrolytes, cationic polyelectrolytes and/or polyampholytes and of cationic, anionic, non-ionic and/or amphoteric surfactants.

Description

Mesomorphic complexes of polyelectrolytes and surfactants, processes for their production and films, foils, fibers, moldings and coatings from them

description

The present invention relates to new mesomorphic complexes comprising anionic polyelectrolytes, cationic polyelectrolytes and / or polyampholytes and cationic, anionic, nonionic and / or amphoteric surfactants. The invention further relates to processes for their production and films, foils, fibers, moldings and coatings therefrom.

It is known that polyelectrolyte complexes spontaneously form between polyelectrolytes and oppositely charged surfactants. The complex formation between polyelectrolytes and non-ionic surfactants is also described. The majority of the corresponding publications deal with aqueous solutions of these complexes, whereas little is known about the properties and structure of such polyelectrolyte-surfactant complexes as solids.

EP-A 492 188 (1) describes solid, amorphous complexes of polyelectrolytes and oppositely charged surface-active agents which can be used as sorbents for the purification of water contaminated by organic compounds. The complexes are obtained as precipitates by mixing the polyelectrolyte and the surfactant in a solvent or by producing the polyelectrolyte in a solution of the surfactant by polymerization.

DD-A 270 012 (2) describes the production of membranes from a polyelectrolyte complex consisting of cellulose sulfate and a cationic surfactant. The membranes are produced by precipitating a film of cellulose sulfate with an aqueous solution of the cationic surfactant to form an amorphous polyelectrolyte complex.

The materials, such as films or membranes, built up from these amorphous polyelectrolyte complexes are often in need of improvement in their mechanical, thermal or application properties. It is therefore an object of the present invention to provide such materials with improved properties. Accordingly, the mesomorphic complexes of polyelectrolytes and surfactants defined at the outset were found.

Substances or materials with a mesomorphic phase, i.e. with liquid-crystalline structure, in which - at least in certain areas - there is an order of the molecular building blocks or an order of the super-molecular aggregates. They differ from amorphous substances or materials e.g. in that they have special optical properties due to their anisotropy.

Obviously, the orientation or ordering of the molecular building blocks and super-molecular aggregates in a mesoscopic or larger dimension is highly advantageous for a number of applications. The degree of order of the material includes the mechanical, thermal and also the optical properties of the material in question are influenced.

Here, the orientation of the molecular building blocks and the super-molecular aggregates compared to the corresponding amorphous material results in an improvement in the application properties or even the appearance of new, desirable properties.

The mesomorphic structure of the polyelectrolyte-surfactant complexes according to the invention is clearly demonstrated by means of small-angle X-ray diffractometry. One or more narrow scattering peaks can be seen here, which characterize a liquid-crystalline morphology. Furthermore, polarization microscope images under crossed polarizers show typical textures of birefringent domain structures in most mesomorphic structures.

The mesomorphic complexes of polyelectrolytes and surfactants according to the invention consist of one or a mixture of several polyelectrolytes and one or a mixture of several surfactants. The complexes can preferably

from one or more anionic polyelectrolytes and one or more cationic and / or nonionic surfactants or

of one or more cationic polyelectrolytes and one or more anionic and / or nonionic surfactants or of one or more anionic polyelectrolytes, cationic polyelectrolytes and / or polyampholytes and one or more nonionic surfactants or

- From one or more polyampholytes and one or more ionic, amphoteric and / or nonionic surfactants

be constructed.

Polyampholytes are understood to be externally neutral amphoteric polyelectrolytes.

Anionic polyelectrolytes are normally those which contain 20 to 100 mol% of one or a mixture of several of the following monomer units of group (1):

Group (1): Monoethylenically unsaturated C ₃ - to Cio-monocarboxylic acids, their alkali metal salts and / or ammonium salts, for example acrylic acid, methacrylic acid, dimethylacrylic acid,

Ethyl acrylic acid, allylacetic acid or vinyl acetic acid; furthermore monoethylenically unsaturated C ₄ to C ₈ dicarboxylic acids, their half esters, anhydrides, alkali metal salts and / or ammonium salts, for example maleic acid, fumaric acid, itaconic acid, mesaconic acid, methylene malonic acid, citraconic acid, maleic anhydride, itaconic anhydride or methylmalonic anhydride; further monoethylenically unsaturated monomers containing sulfo groups, for example allylsulfonic acid, styrene sulfonic acid, 2-acrylamido-2-methylpropanesulfonic acid, methallylsulfonic acid, vinyl sulfonic acid, acrylic acid 3-sulfopropyl ester or methacrylic acid 3-sulfopropyl ester; further monoethylenically unsaturated monomers containing phosphonic acid groups, for example vinylphosphonic acid, allylphosphonic acid or acrylamidomethylpropanephosphonic acid.

These polyelectrolytes can be used in the acid form, partially neutralized or completely neutralized. Up to 80 mol% of the monomer units of the anionic polyelectrolyte can consist of one or more nonionic monomers of group (2):

Group (2): CT.- to C ₂ o ~ alkyl and hydroxyalkyl esters of mono-ethylenically unsaturated C - to Cio-monocarboxylic acids or Cή- to Cs-dicarboxylic acids, for example methyl acrylate, ethyl acrylate, n-butyl acrylate, stearyl acrylate, maleic acid diethyl ester, hydroxy - ethyl acrylate, hydroxypropyl acrylate, hydroxybutyl acrylate, hydroxyethyl methacrylate or hydroxypropyl methacrylate; Farther (Meth) acrylic acid esters of alkoxylated Ci to -C ₈ alcohols which are reacted with 2 to 50 moles of ethylene oxide, propylene oxide, butylene oxide or mixtures thereof; furthermore amides and N-substituted amides of monoethylenically unsaturated C ₃ - to Cio-monocarboxylic acids or C - - to C ₈ -dicarboxylic acids, for example acrylamide, methacrylamide, N-alkylacrylamides or N, N-dialkylacrylamides with je¬ Weil 1 to 18 carbon atoms in the alkyl group such as N-methyl acrylamide, N, N-dimethylacrylamide, N-tert-butylacrylamide or N-octadecyl-acrylamide, maleic acid monomethylhexylamide, maleic acid monodecylamide, dimethylaminopropyl methacrylamide or acrylamidoglycolic acid; further alkyl inoalkyl (meth) acrylates, for example dimethylaminoethyl acrylate, dimethylaminoethyl ethacrylate, ethylaminoethyl acrylate, diethylaminoethyl methacrylate, dimethylaminopropyl acrylate or dimethylaminopropyl methacrylate; furthermore vinyl esters, for example vinyl formate, vinyl acetate or vinyl propionate, which may also have been saponified after the polymerization; furthermore N-vinyl compounds, for example N-vinylpyrrolidone, N-vinylcaprolactam, N-vinylformamide, N-vinyl-N-methylformamide, 1-vinylimidazole or 1-vinyl-2-methylimidazole; furthermore vinyl ethers from C-- to Ci ₈ alcohols, vinyl ethers from alkoxylated C _\ - to C-. ₈ -alcohols and vinyl ethers of polyalkylene oxides such as polyethylene oxide, polypropylene oxide or polybutylene oxide; furthermore linear, branched or cyclic olefins, for example ethene, propene, butenes, isobutene, 1-pentene, cyclopentene, 1-hexene, 1-heptene, 1-octene, 2, 4, '-trimethylpentene-1, 1 -Nones, 1-decene, styrene or its derivatives such as α-methylstyrene, indene, dicyclopentadiene or higher olefins bearing reactive double bonds such as oligopropene and polyisobutene.

Cationic polyelectrolytes are normally those which carry amino groups and / or ammonium groups in the main and / or side chain. For the preparation of polymers containing amino or ammonium groups, e.g. the monomers listed in group (3) are used in proportions of 20 to 100 mol%.

Group (3):

Monomers bearing amino or imino groups, e.g. Dimethylaminoethyl acrylate, diethylaminoethyl acrylate, dimethylaminopropyl ethacrylamide, allylamine;

Monomers which carry quaternary ammonium groups, for example in the present case as salts, as are obtained by reacting the basic amino functions with acids, such as, for example, hydrochloric acid, sulfuric acid, nitric acid, formic acid or acetic acid, or in quaternary form (suitable quaternizing agents are, for example, dimethyl sulfate, diethyl sulfate, methyl chloride, ethyl chloride or benzyl chloride), such as, for example, dimethylaminoethyl acrylate hydrochloride, diallyldimethylammonium chloride, diethylaminoethyl acrylate methochloride, dirnethylaminoethylaminopropyl methazolidiumzolidiumzolidiumzolidiumazolidiumzolidiumzolidiumazolidiumzolidiumazolidiumzolidiumazolidiumazolidiumzolidiumazolidium methazolidium methazolidium methazolidium methacrylate methylsulidium sulfate;

Monomers in which the amino group and / or ammonium group is only released after the polymerization and subsequent hydrolysis, such monomers are e.g. N-vinylformamide and N-vinylacetamide.

Polyethyleneimine or polypropyleneimine can furthermore be used as cationic polyelectrolytes.

These polyelectrolytes can be used in the base form, neutralized or completely neutralized. Up to 80 mol% of the monomer units of the cationic polyelectrolyte can consist of one or more nonionic monomers of group (2).

Usable polyampholytes (amphoteric polyelectrolytes) are generally prepared by copolymerization of 20 to 80 mol% of monomers from group (1) and from group (3), the remaining 0 to 80 mol% of nonionic monomers of Group (2) can exist.

Suitable anionic surfactants are, for example, alkylbenzenesulfonates, fatty alcohol sulfates, fatty alcohol polyglycol ether sulfates, alkylglyceryl ether sulfonates, fatty alcohol polyglycol ether methylcarboxylates, paraffin sulfonates, olefin sulfonates, sulfoberstein acid and semiesterates and alkylphenol ether sulfates, and alkylphenol ether sulfates. Typical compounds of this type are, for example C ₈ - to C (--Alkansulfonate, C: ₂ - to Ci6-alkyl sulfates, _C:? - to C ₆ -Alkylsulfosuccinate and sulfated ethoxylated C; ₂ ~ -C; ₆ ~ Alkanols.

Also suitable as anionic surfactants are sulfated fatty acid alkanolamines, α-sulfofatty acid esters or fatty acid monoglycerides. Other suitable anionic surfactants are fatty acid esters or fatty acid sarcosides, glycolates, lactates, taurides or isothionates.

The anionic surfactants can be in the form of the sodium, potassium or ammonium salts and as soluble salts of organic bases such as

Mono-, di- or triethanolamine or other substituted amines available. The anionic surfactants also include the usual soaps, ie the alkali metal salts of the natural fatty acids.

As nonionic surfactants (Nonionics) e.g. Polyalkylene oxide adducts such as ethylene oxide / propylene oxide block polymers, fatty acid esters of polyhydroxy compounds, e.g. Sorbitan alkyl esters, glyceryl alkyl esters, fatty acid alkylolamides or fatty acid alkylol amidooxethylates, and addition products of 3 to 40, preferably 4 to 20, moles of ethylene oxide with 1 mole of fatty alcohol, alkylphenol, fatty acid, fatty amine, fatty acid amide or alkanesulfonamide can be used. Nonionic surfactants of the amine oxide or sulfoxide type can also be used.

Cationic surfactants which are normally used are those which contain ammonium groups, the ammonium compound being able to be based on an open-chain amine, for example C ₈ -C ₈ -alkyltrimethyla monium chloride or bromide, ditallow dimethylammonium chloride or laurylbenzyldimethylammonium chloride. Cationic surfactants based on a cyclic amine or imine, for example pyridinium, imidazolinium,

Cationic surfactants containing Piperidiniu, oxazolinium or pyrimidinium groups.

Suitable amphoteric surfactants which are neutral to the outside generally carry basic groups such as amino groups and acidic groups such as sulfonate, sulfate or carboxyl groups. Suitable amphoteric surfactants are, for example, mono- and di-alkylaminopropylamino-carboxylic acids and phosphoglycerides.

The mesomorphic polyelectrolyte-surfactant complexes according to the invention are preferably prepared in such a way that a solution of a surfactant, usually in a stoichiometric excess with respect to the ionic groups of the polyelectrolyte, results in a (partially) neutralized aqueous solution of the polyelectrolyte with the opposite charge to the surfactant ionic groups are added. In order to dissolve the precipitated complex, which still has an amorphous structure, an organic solvent is added for the purposes of the present invention, preferably an alcohol which is not miscible with water in all proportions, such as 2-butanol, an ester, in particular carboxylic acid esters, such as ethyl acetate, an ether such as tetrahydrofuran, a ketone such as butanone or a mixture of such solvents in which the complex can be redissolved. If necessary, excess surfactant and salt can be washed out by washing the organic phase several times with water in the sense of a sol-gel separation process.

By evaporation of the organic solvent from the solution or gel phase generated, the polyelectrolyte-surfactant complex becomes mesomorphic structure as a solid, for example as a film. In the solution or gel phase of the mesomorphic polyelectrolyte-surfactant complex, other components such as polymers or low-molecular compounds, e.g. plasticizers, thickeners, compatibilizers, dyes, light stabilizers, but also structure-stabilizing components such as glass fibers or carbon fibers, can also be present, which can then be present in the resultant solid be incorporated.

It is also possible to apply films or layers of the mesomorphic polyelectrolyte-surfactant complexes to suitable inorganic or organic carrier materials from the solution or gel phase produced by evaporation of the organic solvent, and thus to coat the mesomorphic polyelectrolyte surfactant -Complete complex.

To produce the amorphous polyelectrolyte-surfactant complex as a precursor in solution, it is also possible to add non-neutralized surfactants (e.g. didodecylmethylamine) to non-neutralized polyelectrolytes (e.g. polyacrylic acid).

The mesomorphic polyelectrolyte-surfactant complexes according to the invention can also be provided without a solvent by producing them from the melt of the corresponding amorphous polyelectrolyte-surfactant complexes in accordance with the present invention. For this purpose, a melt of a corresponding thermoplastic polyelectrolyte can be mixed with a suitable surfactant or the mixture of a corresponding polyelectrolyte and a corresponding surfactant can be melted and the melt can be further processed in a shaping process. For example, extrusion of the molten polyelectrolyte-surfactant complex allows strands, profiles, plates, tubes or coatings to be produced. In particular, the desired material properties can be achieved by coextrusion with other polymers. Molded parts and films made of thermoplastic polyelectrolyte-surfactant complexes can be produced by injection molding or calendering.

Processing from the melt often requires the addition of various auxiliaries, such as plasticizers. Furthermore, further components such as stabilizers, fillers or dyes can be added to the melt of the polyelectrolyte-surfactant complex. If necessary, mixtures of the polyelectrolyte-surfactant complex with other polymers and compatibilizers from the melt can also be processed. The present invention also relates to materials which can be used in industry, ie films, foils, fibers, moldings and coatings, moldings being for example strands, profiles, plates, tubes but also granular masses or granules which meso¬ morph the invention Contain or consist of complexes of polyelectrolytes and surfactants.

The content of these materials in the mesomorphic polyelectrolyte-surfactant complexes according to the invention is usually 5 to 100% by weight, in particular 50 to 100% by weight, especially 80 to 100% by weight.

The materials according to the invention mentioned are suitable, for example, as materials for the production of non-porous membranes, as packaging material (for example as a barrier film for gases), for the production of hollow fibers, as a coating material or as components in optical or electro-optical components.

Because of the anisotropic properties of the material, the technical articles listed have improved mechanical, thermal or application properties compared to the corresponding conventional technical articles, for example oxygen-impermeable films can be produced with these materials, which are advantageous for the packaging of perishable foods can be used.

Manufacturing and characterization examples

example 1

Production of polystyrene sulfonate sodium salt (PSSNa)

Anionically polymerized polystyrene (M _w • * 449,000 g / mol, M _w / M _n <1.05) was converted into the sodium salt of polystyrene sulfonic acid using sulfuric acid and phosphorus pentoxide in accordance with H. Vink's instructions (H. Vink, Makromol. Chem. 182, 279, 1981). The degree of sulfonation S was determined by elemental analysis and was S> 0.9. The polystyrene sulfonate sodium salt was dialyzed against demineralized water and freeze-dried. Examples 2 to 5

Preparation of the complex from PSSNa and alkyltrimethylammonium chloride

PSSNa (5.0 g) was dissolved in 0.01 molar aqueous sodium sulfate solution (400 ml). A 1.5-fold stoichiometric excess of dodecyltrimethylammonium chloride (9.6 g) dissolved in deionized water (100 ml) was added dropwise. The precipitated complex was filtered off and washed with water.

The dodecyltrimethylammonium chloride (Example 2) was replaced by 10.6 g tetradecyltrimethylammonium chloride (Example 3), 11.6 g hexadecyltrimethylammonium chloride (Example 4) and 12.7 g ocadecyltrimethylammonium chloride (Example 5). Reactions and workups were carried out analogously to Example 2.

Examples 6 to 9

Purification of the PSSNa-alkyltrimethylammonium chloride complexes from Examples 2 to 5

The precipitated complex, which still contained certain amounts of excess surfactant and salt formed, was dissolved in 2-butanol. Demineralized water was added until a phase separation into a complex-rich gel phase and a surfactant- and salt-rich aqueous phase occurred. The aqueous phase was discarded and the sol-gel separation process was repeated several times until the water phase was practically free from halide ions (detection with AgNO).

Examples 10 to 13

Preparation of mesomorphic films from the purified PSSNa-alkyltrimethylammonium chloride complexes of Examples 6 to 9

The gel phase of the complex in 2-butanol was poured onto a planar glass plate which had been pretreated with octadecyltrichlorosilane. The two-dimensional geometry of the film being formed was specified here by a variably adjustable sheet metal frame which was mounted on the glass surface. After the 2-butanol solvent had evaporated slowly, the film could be easily peeled off the glass surface.

Examples 14 to 17

Measurement of the small-angle X-ray diffraction pattern of the mesomorphic films from Examples 10 to 13 The small-angle X-ray diffractograms were measured with an Anton Paar Kompakt Kratky camera with a Cu-Kα source (Phillips pwl830 generator). The monochromatization was carried out with a nickel filter. There was a pulse height discrimination. The measurements were carried out in a scatter vector range from 1.0 · 10 ^-3 A-ι to 9.0 · 10 ^ A " ^1. The scatter vector s is defined by s = 2 / λ • sin θ, where 2θ denotes the angle between the incident and scattered beam and λ means the wavelength of the radiation used.

The table according to Example 21 shows the results of the measurements on the films from Examples 10 to 13.

Example 18 Preparation of a complex of polyacrylic acid and dodecyltrimethylammonium chloride

Polyacrylic acid (5.0 g, M _w = 250,000 g / mol) was dissolved in water and converted into the sodium salt with NaOH. A solution of dodecyltrimethylammonium chloride (24 g) in water (200 ml) was added dropwise with stirring. The precipitated complex was filtered off.

Example 19 Purification of the complex from Example 18

The cleaning was carried out in analogy to the method given in Examples 6 to 9.

Example 20

Preparation of a mesomorphic film from the purified complex from Example 19

The mesomorphic film was produced in analogy to the procedure given in Examples 10 to 13.

Example 21

Measurement of the small-angle X-ray diffractograms of the mesomorphic film from Example 20

The measurement was carried out using the method given in Examples 14 to 17. The table below shows the results of the measurement on the film from Example 20. table

Small-angle X-ray diffractograms (location of the main peak)

Example No. I / cps s / nm ^-1

14 98 0.34

15 93 0.32

16 88 0.285

17 260 0.245

21 305 0.30

Claims

claims

1. Mesomorphic complexes of anionic polyelectrolytes, cationic polyelectrolytes and / or polyampholytes and cationic, anionic, nonionic and / or amphoteric surfactants.

2. A process for the preparation of mesomorphic complexes of polyelectrolytes and surfactants according to claim 1, characterized gekenn¬ characterized in that the corresponding amorphous polyelectrolyte-surfactant complexes are dissolved in organic solvents and these solvents are evaporated from the solution or gel phase produced.

3. A process for the preparation of mesomorphic complexes from polyelectrolytes and surfactants according to claim 1, characterized gekenn¬ characterized in that they are prepared by processing from the melt of the corresponding amorphous polyelectrolyte-surfactant complexes.

4. Films, foils, fibers, moldings and coatings containing entes mesomorphic complexes of polyelectrolytes and surfactants according to claim 1.