EP2087154A1

EP2087154A1 - Polyethylenimine nanoparticle-containing microbicidal electrospun polymer fibers for textile applications

Info

Publication number: EP2087154A1
Application number: EP07816192A
Authority: EP
Inventors: Andreas Greiner; Thorsten RÖCKER
Original assignee: Schoeller Textil AG
Current assignee: Schoeller Textil AG
Priority date: 2006-10-23
Filing date: 2007-10-17
Publication date: 2009-08-12
Also published as: WO2008049250A1; CN101563486A; WO2008049250B1; US20100292623A1

Abstract

The invention relates to polymer fibers with microbicidal properties, comprising at least one polymer that can be electrospun and nanoparticle-containing quaternized polyethylenimine and to a method for producing said fibers. The use of the polyethylenimine nanoparticles (PEIN) allows polymers that can be electrospun to be provided with a microbicidal finish. A prerequisite for this is that the polyethylenimine nanoparticles are particles from derived polyethylenimine (PEI), since pure, underived PEI has no antibacterial effect. Preferably, quaternized polyethylenimine is used. The polymers that can be electrospun are coated with PEIN either during and/or after electrospinning. The polymer fibers that can be obtained by the method according to the invention can be used for textile fibers, for example for producing fibers for activity clothing, protective clothing for medical staff and protective clothing for patients, for medical drapes and dressings or for nonwovens or fiber mats for cell culture substrates.

Description

MICROBICIDE ELECTROGES PONNENE POLYMER FIBERS WITH POLYTHYLENIMINE NONOPARTICLES FOR TEXTILE APPLICATIONS

The present invention describes a process for producing electrospun fibers comprising polyethyleneimine nanoparticles (PEIN). The use of PEIN allows the antibacterial properties of electrospun polymers, provided that these polyethylenimine nanoparticles are particles of derivatized polyethylenimine (PEI), since pure, underivatized PEI has no antibacterial effect. Preferably, quaternized polyethyleneimine is used. The assignment of the electrospinnable polymers with PEIN can take place during and / or after the electrospinning. The polymer fibers obtainable by the process according to the invention can be used for textile fibers werderv. for example, for the production of fibers for functional clothing or for nonwovens or fiber mats for cell culture substrates.

Description and introduction of the general field of the invention

The present invention relates to the fields of macromolecular chemistry, process engineering, textile and material sciences.

State of the art

For the production of nanofibres and mesofasems, the skilled worker is familiar with a large number of processes, of which the electrospinning process is of greatest importance at present.This process, which is described, for example, by DH Reneker, HD Chun in Nanotechn. , Page 216 f, a polymer melt or a polymer solution is usually exposed to a high electric field at an edge serving as an electrode, which can be achieved, for example, by subjecting the polymer melt or polymer solution in an electric field under low pressure to a pole Due to the resulting electrostatic charging of the polymer melt or polymer solution, a material stream directed onto the counterelectrode, which solidifies on the way to the counterelectrode, is formed with this method depending on the electrode geometries obtained nonwovens or ensambles ordered fibers. While with polymer melts so far only fibers with diameters greater than 1000 nm are obtained, one can produce from polymer solutions fibers with diameters greater than or equal to 5 nm.

The prior art knows some processes for the production of polymer fibers by means of electrospinning:

DE 10 2004 009 887 A1 relates to a process for the production of fibers with a diameter of <50 μm by electrostatic spinning or spraying of a melt of at least one thermoplastic polymer.

DE 101 33 393 A1 discloses a process for producing hollow fibers having an inner diameter of 1 to 100 nm, in which a solution of a water-insoluble polymer - for example, a poly-L-lactide solution in dichloromethane or a polyamide-46 solution in pyridine - is electrospun. A similar method is also known from WO 01/09414 A1 and DE 103 55 665 A1.

DE 196 00 162 A1 discloses a process for the production of lawnmower wire or textile fabrics in which polyamide, polyester or polypropylene as a filament-forming polymer, a maleic anhydride-modified polyethylene / polypropylene rubber and one or more aging stabilizers are combined, melted and bonded together are mixed before this melt is melt-spun.

For some applications of fibers, it is desirable to be able to inhibit the growth and / or proliferation of microorganisms. Microorganisms are understood as meaning bacteria, fungi, algae, protozoa and viruses. Fibers with microbicidal properties are particularly useful in the medical field, for example for wound dressings or textiles for patients and medical personnel. Unless otherwise stated, the terms microbicide and microbicide are to be used below as collective headings for agents for combating microorganisms or for an antimicrobial effect. The action against microorganisms can be reversibly or irreversibly growth-inhibiting (for example bacteriostats or fungistatics) or killing (for example bactericides or fungicides).

It is known to the person skilled in the art that some organic nitrogen-containing compounds have microbicidal properties.

Thus, DE 32 37 074 A1 describes polymer biguanides which can be used as microbicides in disinfectants, the polymer biguanides inhibit, for example, the growth of Aspergillus niger, Eschericia coli, Staphylococcus aureus, Pseudomonas aeruginosa and Chaetonium globosum. DE 33 14 294 A1 describes condensed polyalkyleneimine polymers by means of which biological materials such as whole cells and enzymes can be immobilized. For this purpose, the polyalkyleneimines are condensed together with a dicarboxylic acid to form a copolymer. Optionally, the copolymer is subsequently post-treated with an amine crosslinking component. However, no derivatized polyalkyleneimines are used.

DE 34 23 703 A1 describes polymeric quaternary ammonium compounds which are obtained by reaction of polymers of the ionene type with tertiary amines. These polymeric quaternary ammonium compounds according to the invention have microbicidal properties. There are further described methods for inhibiting the growth and proliferation of microorganisms wherein the microorganisms are contacted with the polymeric quaternary ammonium compounds of the present invention. However, these polymeric quaternary ammonium compounds have no crosslinking of the polymer chains, and it is explicitly stated that polyethylenimines are not good microbicides.

N Beyth et al., Biomaterials 27, 2006, 3995-4002 describes the preparation and use of ammonium polyethylene nanoparticles in dental composite composites. For this purpose, polyethylenimine (PEI) is crosslinked in the first step with dibromopentane, the cross-linked PEI is alkylated in the second step with bro- moctan and in the third step the secondary or tertiary amino groups of the alkylated and cross-linked PEI are quaternized with methyl iodide. The PEI particles obtained in this way were added to composite resins for dental fillings and incubated with the oral bacterium Streptococcus mutans. The PEI particles inhibited bacterial growth over a period of one month. However, the PEI particles could not be incorporated permanently into the composite material.

So far, the prior art knows no method to equip textile fibers permanently or in the short term with polyethyleneimine particles and thus to give the fibers a microbicidal effect. task

The object of the present invention is to provide polymer fibers with microbicidal properties and processes for their preparation.

Solution of the task

The object of the ready division of polymer fibers having microbicidal properties is achieved according to the invention by polymer fibers comprising at least one electrospinnable polymer and nanoparticles containing quaternized polyethyleneimine.

According to the invention, the at least one electrospinnable polymer is selected from the group consisting of poly (p-xylylene); Polyvinylidene halides, polyesters such as polyethylene terephthalates, polybutylene terephthalate; polyether; Polyolefins such as polyethylene, polypropylene, poly (ethylene / propylene) (EPDM); polycarbonates; polyurethanes; natural polymers, eg rubber; polycarboxylic acids; Polysulfonic acids; sulfated polysaccharides; polylactides; polyglycosides; polyamides; Homo- and copolymers of aromatic vinyl compounds such as poly (aikyl) styrenes), for example polystyrenes, poly-alpha-methylstyrenes; Polyacrylonitriles, polymethacrylonitriles; polyacrylamides; polyimides; Polyphenylene; polysilanes; polysiloxanes; Polybenzimidazoles; polybenzothiazoles; polyoxazoles; polysulfides; polyester; Polyarylene-vinylenes; polyether ketones; Polyurethanes, polysulfones, inorganic-organic hybrid polymers such as ORMOCER® from the Fraunhofer Society for the Advancement of Applied Research Munich; silicones; wholly aromatic copolyesters; ! Po y (alkyl) acrylates; Poly (alkyl) methacrylates; polyhydroxyethylmethacrylates; Polyvinyl acetates, polyvinyl butyrates; polyisoprene; synthetic rubbers such as chlorobutadiene rubbers, eg Neoprene® from DuPont; Nitrile butadiene rubbers, eg Buna N®; polybutadiene; polytetrafluoroethylene; modified and unmodified celluloses, homopolymers and copolymers of alpha-olefins and copolymers composed of two or more monomer units forming the abovementioned polymers; Polyvinyl alcohols, polyalkylene oxides, eg polyethylene oxides; Poly-N-vinylpyrrolidone; hydroxymethylcelluloses; maleic; alginates; Collagens.

All of the abovementioned polymers can be used in the polymer fibers according to the invention having microbicidal properties in each case individually or in any desired combinations with one another, in any desired mixing ratio.

According to the invention, the nanoparticles contain derivatized, preferably quaternized, polyethyleneimine of the general formula

wherein m, n are independently a natural number of 5 to 200, p is a natural number of 4 to 6, q is an integer of 0 to 11, and r is an integer of 0 to 4, and wherein X = Br or I means.

The object of providing a process for producing polymer fibers having microbicidal properties comprising at least one electrospinnable polymer and nanoparticles comprising quaternized polyethyleneimine is achieved according to the invention by a process comprising the steps of a) crosslinking of polyethyleneimine, b) alkylation of cross-linked polyethyleneimine, c) quaternization of secondary and tertiary amino groups of polyethyleneimine, d) separation of the quaternized polyethyleneimine nanoparticles, e) addition of the polyethyleneimine nanoparticles to a solution of at least one electro-spinnable polymer, f) electrospinning of the polyethyleneimine nanoparticles containing solution of the at least one electro-spinnable polymer into fibers.

The process steps are explained in detail below:

a) Crosslinking of Polyethyleneimine (PEI)

The crosslinking is carried out according to the following scheme:

1. l, ω-X- (CH ₂ ) _p -X 24 h reflux

where n, m, p and X are as defined above.

A commercial aqueous polyethyleneimine solution is completely dehydrated by refluxing in toluene and using a water separator. The anhydrous PEI is then reacted with a linear unbranched 1, ω-dihalo genoalkane having 4 to 6 carbon atoms as crosslinking agent, where "halogen" is bromine or iodine The dibromoalkanes to be used as crosslinkers are therefore selected from 1, 4-dibromobutane, 1, 4-diiodo-butane, 1, 5-dibromopentane, 1, 5-diiodopentane, 1, 6-dibromohexane and 1, 6-diiodohexane.

b) Alkylation of Crosslinked Polyethyleneimine

The alkylation of the crosslinked polyethyleneimine is carried out according to the scheme

Ethano!

where n, m, p and q have the meanings given above. The crosslinked PEI is alkylated with a linear unbranched 1-bromoalkane having 1 to 12 carbon atoms. The alkylation is preferably carried out using 1-bromoalkanes having 7 to 9 C atoms, ie 1-bromoheptane, 1-bromooctane or 1-bromononane.

c) Quaternization of secondary and tertiary amino groups of the polyethylene imine

The quaternization of the secondary and tertiary amino groups of the polyethylen lenimins follows the scheme

h RT yridin

where m, n, q, r and X have the meanings given above.

For the quaternization, the alkylated, cross-linked PEI is reacted with a linear, unbranched 1-haloalkane having 1 to 5 C atoms, where "halogen" is bromine or iodine Preferably, an iodoalkane is used for the quaternization, more preferably methyl iodide. Polyvinylpyridine is used as proton sponge in this reaction.

d) Separation of the quaternized Polyethyienimin nanoparticles

The polyethylenimine nanoparticles obtained after carrying out steps a) to c) are obtained in the form of a powder and can be separated off from the reaction mixture, for example by filtration. The obtained PEI nanoparticles (are well dispersed in tetrahydrofuran (THF), ethanol and formic acid.

e) adding the polyethyleneimine nanoparticles to a solution of the at least one electro-spinnable polymer

At least one electro-spinnable polymer is dissolved, preferably in THF; Ethanol or formic acid, and then Polyethyienimin nanoparticles are added. In this case, preferably those solutions are prepared which contain 5 wt .-% to 25 wt .-% of the electro-spinnable polymer and 0.01 wt .-% to 5 wt .-% Polyethyienimin nanoparticles.

f) electrospinning the polyethyieneimine nanoparticle-containing solution of the at least one electro-spinnable polymer into fibers

This solution is exposed to a high electric field on an electrode edge. For example, this can be done by the solution containing the Polyethyienimin nanoparticles solution of the electro-spinnable polymer in an electric field at low pressure through a with a pole of a Voltage source connected to the cannula is extruded. The result is a flow of material directed at the counterelectrode, which solidifies on the way to the counterelectrode.

Alternatively, the solution of the at least one electro-spinnable polymer can also first be spun into fibers without adding to the spinning solution polyethyleneimine nanoparticles. In this case, the eiektrosponnenen polymer fibers can subsequently be coated with PEI nanoparticles, according to the following process steps: a) crosslinking of polyethyleneimine, b) alkylation of crosslinked polyethyleneimine, c) quaternization of secondary and tertiary amino groups of Polyethyle- nimins, d) separation of the quaternized polyethyleneimine nanoparticles; e) addition of the polyethyleneimine nanoparticles to a solution of at least one electrospincable polymer; f) coating of the electrospun fibers with polyethyleneimine nanoparticles.

The subsequent covering of the electrospun fibers with polyethyleneimine nanoparticles can be carried out, for example, but not exhaustively, by gas phase deposition, knife coating, spin coating, dip coating, spraying or plasma deposition. These methods are known to those skilled in the art and can be used without departing from the scope of the claims. Optionally, the polyethyleneimine nanoparticles may be spun into fibers together with the at least one electro-spun polymer, as well as used to subsequently coat the fibers.

In the polymer fibers according to the invention having microbicidal properties, the proportion of polyethylenimine nanoparticles is 0.1% by weight to 25% by weight. The polymer fibers according to the invention having microbicidal properties inhibit the growth and / or proliferation of microorganisms. Microorganisms are understood as meaning bacteria, fungi, algae, protozoa and viruses.

The microbicidal polymer fibers obtainable by the method according to the invention can be used for the production of textile fibers and fabrics, for example for the production of fibers for fabrics for the production of functional clothing, protective clothing for medical personnel and protective clothing for patients, also for medical drapes and Wound dressings or for nonwovens or fiber mats for cell culture substrates.

embodiments

1. Preparation of Polyethylenimine Nanoparticles.

Polyethyleneimine nanoparticles were prepared as described under "Solution of the problem." In the second reaction step - the alkylation of the cross-linked PEI - 2-bromooctane was used in the second reaction step - the qua - Ternization of the secondary and tertiary amino groups of PEI - was Methylliodid used in THF.

2. Preparation of antibacterial nanofibers based on PVB

The ethanol-soluble polymer polyvinyl butyrate (PVB, trade name Mowital) was used. Repeating unit of polyvinyl butyrate:

Polyvinyl butyrate (M _w = 19640, M _n = 159,000, M _w / M _n = 1, 23) was dissolved in ethanol at room temperature with stirring. The concentrations of the prepared solutions were 10 wt% and 15 wt%. In order to provide the fibers with antibacterial properties, in each case 2% by weight of quaternized PEI particles were added to the polymer solutions and dispersed in the polymer solutions with stirring at room temperature. The PVB dispersions were then electrospun. The following parameters were set on the electrospinning device: Voltages: 15 kV, 20 kV, 25 kV, 30 kV Distance between cannula and electrode: 20 cm diameter Cannula: 0.3 mm

Flow rates: 0.86 mL / hr, 1.21 mL / hr, 1.56 mL / hr

The substrates used were aluminum foil and aluminum sheet frames.

The resulting fibers had an average diameter of 1, 3 to 1, 5 microns.

This diameter is quite high for electrospun fibers, but is explained by the high viscosity and low electrical conductivity of the solution. Both sizes are shown in Table 1. The finished fibers showed a pale yellow color. This suggests, without further investigation, that the yellow nanoparticles are incorporated in the fibers or adsorbed on the fibers. Under the SEM (Figure 3), the fibers are smooth and show no foreign bodies adsorbed on the surface.

Table 1: Characterization of the PVB solution used in EtOH

Concentration ViskosiGehalt to Electrical Oberflächenpanpan¬

PVB PEI particles conductivity conductivity

/ wt% / Pa-s / wt% / μS / cm / mN / m

15 1, 399 2 4.98 22.98

Since optical confirmation of the presence of the particles was not possible, an EDX study was made of the fibers produced. The spectrum in Fig. ^ Shows in addition to the signal for carbon and oxygen only a clear signal for iodine. However, iodine can only be introduced into the fibers in these quantities as counterion to the quaternary ammonium ions in the PEI particles.

Since the iodine is present in the PEI particles as a counterion to the quaternary ammonium ions and can not be separated from them, these particles must be removed. neither in the fibers nor on the fibers. Thus, the presence of the active ingredient on the PVB fibers is detected.

3. Preparation of antibacterial nanofibers based on polyamide

Polyamide 66 was used (PA 66); the repetition unit is

The polyamide solution also allowed to spin into fibers but the fibers produced did not show any color.

Po) yamid-66 was dissolved in formic acid with stirring at room temperature. The concentration of the prepared solution was 15wt%. In order to provide the fibers with antibacterial properties, 2% by weight quaternized PEI particles were added to the polymer solution and dispersed in the polymer solution with stirring at room temperature.

The PA 66 dispersion was then electrospun. The following parameters were set on the electrospinning system: Voltages: 55 kV, 60 kV Distance between cannula and electrode: 20 cm diameter Cannula: 0.3 mm Flow rates: 0.52 mL / h, 0.86 mL / h The substrates used were aluminum foil and aluminum sheet frames ,

The average fiber diameter was 833 nm. Under the electron microscope, as in PVB, the fibers are smooth and have no surface structures, as shown in Figs. 5a and 5b.

The spiderweb-like structures seen in Figure 5b are well known in spinning polyamide. To check the presence of the particles in the To prove fibers was also taken up by these fibers an EDX spectrum. Here, too, iodine can be detected in the fibers, as the EDX spectrum in FIG. 6 proves.

The properties of the spun PA 66 solution are listed in Tab.

Table 2: Characterization of a used solution of PA 66 in formic acid Concentration Viscosity content on PEI- Electric conductive surface chip PA 66 did particle capacity / wt% ^' / Pa-s / wt% / μS / cm / mN / m ~ 0.5 0.659 05 879 34.62

4. Investigation of the antibacterial efficacy of the nanofibre nonwovens produced

The antibacterial activity of both PVB and PA 66 fibers was tested.

For this purpose, agar plates were either inoculated with Eschericia coli or with Micrococcus lυteus, mixed with an appropriate nutrient medium and incubated until confluency.

Subsequently, samples of the PEI nanoparticles! PVB or PA 66 fiber mats containing applied to the confluent E. coli or M. luteus ZeWen and incubated for a further 24 h at room temperature. Subsequently, the effect of the fibers on the growth of the bacteria was recorded with a camera. 5. Antibacterial effectiveness of PVB fibers

Fiber mats made of PVB with a content of 13% by weight PEl nanoparticles were produced. The antibacterial activity was tested against E. coli and M. luteus as listed under 4..

Neither E. coli nor M.luteus cells can exist on the PVB fiber mats, and around the fiber mats a bacteria-free zone forms. The bacteria-free zone is even significantly larger in the case of M. luteus than in E. coli, although M. luteus is generally the more resistant of the two bacteria.

The antibacterial activity of the PVB fiber mats with 13% by weight PEI nanoparticles on the two bacterial strains is shown in FIGS. 7a (E. coli) and 7b (M. luteus).

However, the problem with PVB fibers is that they tend to degenerate under moist, warm conditions, such as those prevailing in the cultivation of the bacterial strains mentioned. PVB fibers containing PEI nanoparticles are therefore particularly suitable for those purposes where a relatively short-term (one-off), but wide-area and strong antimicrobicidal action is desired.

6. Antibacterial activity of PA 66 fibers

Fiber mats were produced from PA 66 with a proportion of 13% by weight of PEI nanoparticles. The antibacterial activity was tested against E. coli and M. luteus as listed under 4..

In the case of the PA 66 fibers with 13% by weight PEI nanoparticles, no bacteria-free zone is formed when the fibers are tested against Eschericia coli (Figure 8a). However, if the fiber mat is raised, a bacteria-free to see rich (Fig. 8b), which corresponds in shape exactly to the previously resting fiber mat.

The test against Micrococcus luteus forms a bacteria-free zone around the fiber mat (Figure 8c).

Although polyamide fiber mats can no longer degenerate, they still have antibacterial activity against Micrococcus luteus and Escherichia coli. The antibacterial effect is essentially due to the biocidal effect of the fiber surfaces and not by a release of the PEI particles from the fibers as in the PVB based fibers. Surprisingly, the bacteria-free zone phenomenon in the Micrococcus luteus test also occurs in the PA 66 fibers. But this can only happen if particles can diffuse out of the fibers. Due to the substantial lower fiber degeneration in the polyamide fibers, this means that Micrococcus luteus reacts much more sensitively to the PEI particles than Escherichia coli.

7. Screening of microbicidal effect of different proportions of PEI particles in PA 66 fibers on the growth of Micrococcus luteus and Eschericia coli

To quantify the microbicidal efficacy of PA 66 fibers with PEI nanoparticles on the growth of Eschericia coli and Micrococcus luteus, a series of experiments was performed with different proportions of PEI particles in the PA 66 fibers. The solutions shown in Tab. 3 were spun into nanofibers, and then the fiber mats were tested for their activity against Escherichia coli and Micrococcus luteus as described under 4.. Table 3 Effectiveness of fibers from a solution of 15 wt% PA 66 in formic acid with variable content of PEI particles

Content of PEI content of PEI effective against effective against

Particles in the particles in the Escherichia coli Micrococcus lutθus

Solution fibers

/ wt% / wt%

0 0 no no

0.17 1, 1 no partially

0.2 1, 3 no yes

0.6 4 no yes

1 6 no yes

2 13 yes yes

The results shown in Table 3 are shown in FIG.

Since the antibacterial effect of the nanofibers against Escherichia coli is only visible when the fiber mat is removed from the lawn, all fiber mats tested against Escherichia coli were removed from the bacterial lawn to test for efficacy. As expected, the fibers without particles show no biocidal effect. Bacteria grow under the fibers, and the fibers tested against Micrococcus luteus do not even have to be lifted because the intense yellow bacteria lawn is visible through the fiber mat. Overall, the test against Escherichia coli was always negative, under all fiber mats bacterial lawns were found. Only the first tested concentration of 13 wt% PEI particles has shown an antibacterial activity against Escherichia coli. Thus, the limit for effective use of the particles against Escherichia coli is 13 wt%. In Micrococcus luteus, the test was positive in most cases. With a proportion of 6 wt% particles in the fibers formed a bacteria-free zone, at proportions of 4 wt% and 1, 3 wt%, the area in which the fiber mats were resting on the nutrient medium, completely bacteria-free. With a proportion of 1, 1 wt% PEI particles, a precise statement about the effectiveness of the fibers against Micrococcus tuteus is difficult. Although section B2 in FIG. 9 shows that a bacteria-free zone exists below the fibers, a closer examination in FIG. 10 shows that yellow fibers adhere to the fibers so firmly that they can be reversed by the fiber mat Such a firmly adhering biofilm can only arise if the bacteria grow on the fibers themselves. Such growth of bacteria on the fiber mats can no longer be detected at the higher concentrations of PEI particles in the fiber mats.

For this reason, this sample is considered to be only partially effective against Micrococcus luteus. The limit for effective use of the fibers against Micrococcus luteus is thus at a particle content of at least 1, 3 wt%.

LIST OF REFERENCE NUMBERS

1 voltage source

2 capillary nozzle 3 syringe

4 polyelectrolyte solution

5 counter electrode

6 fiber formation

7 fiber mat

Figure legends

FIG. 1 shows a schematic representation of a device suitable for carrying out the electrospinning process according to the invention.

The device comprises a syringe 3, at the tip of which is a capillary nozzle 2. This capillary nozzle 2 is connected to a pole of a voltage source 1. The syringe 3 receives the polyelectrolyte solutions 4 to be spun. Opposite the outlet of the capillary nozzle 2, a counterelectrode 5 connected to the other pole of the voltage source 1 is arranged at a distance of about 20 cm, which acts as a collector for the fibers formed. During operation of the device, a voltage between 18 kV and 35 kV is set at the electrodes 2 and 5, and the polyelectrolyte solution 4 is discharged through the capillary nozzle 2 of the syringe 3 at a low pressure. Due to the electrostatic charge of the polyelectrolytes in the solution due to the strong electric field of 0.9 to 2 kV / cm, a material flow directed towards the counterelectrode 5, which solidifies on the way to the counterelectrode 5 with fiber formation 6, arises as a result on the counterelectrode 5 fibers 7 with diameters in the micro and nanometer range. Fig. 2 shows the size distribution of the quaternized PEI particles. The particles were previously dispersed in ethanol, then the size distribution was determined by dynamic light scattering. The size (diameter) of the particles is about 20 nm on average.

Fig. 3

Fibers of 15% by weight PVB in ethanol, with 2% by weight PEI particles, SEM uptake, magnification 8,000X.

Fig. 4

EDX spectrum of a fiber mat of PVB, which was mixed with 2 wt .-% PEI particles, acceleration voltage 20 kV.

Fig. 5 fibers from a solution of 15 wt .-% PA 66 in formic acid with an addition of 0.5 wt .-% PEI; a) SEM image, 8,000x magnification, b) SEM image, 20,000x magnification.

Fig. 6

EDX spectrum of fiber mats from a solution of 15% by weight PA 66 in formic acid with 2% by weight PEI particles.

Fig. 7

Fiber mats of PVB with a proportion of 13 wt .-% PEI nanoparticles in the

Fibers, a) placed on a confluent layer of Eschericia coli, incubated for 24 h at room temperature b) placed on a confluent layer of Micrococcus luteus, 24 h incubation at room temperature.

Fig. 8 fiber mats of PA 66 with a proportion of 13 wt .-% PEI nanoparticles in the fibers, a) placed on a confluent layer of Eschericia coli, 24 h incubation at room temperature, b) placed on a confluent layer of Eschericia coli , 24 h incubation at room temperature, after lifting the fiber mat, c) placed on a confluent layer of Micrococcus luteus, 24 h incubation at room temperature.

Fig. 9 Screening of the efficacy of PA 66 fibers with different proportions of PEI particles. Row A: Tested on Eschericia coli, all fiber mats were raised. a) A1) no PEI particles, b) A2) 1, 1 wt% particles, c) A3) 1, 3 wt% particles, d) A4) 4 wt% particles, e) A5) 6 wt% particles.

Row B: Tested against Micrococcus luteus, fiber mats B2 to B4 were lifted off. f) B1) no PEI particles, g) B2) 1, 1 wt% particles, h) B3) 1, 3 wt% particles, i) B4) 4 wt% particles, j) B5) 6 wt% particles. Fig. 10

Enlargement of the image section B2 from FIG. 9:

Here, the effectiveness of PA 66 fibers with 1, 1 wt% PEI particles on the growth of Micrococcus luteus was tested, the fiber mat was lifted. Bacteria adhere to the fibers so firmly that they can not be removed by turning the fiber mat over.

Claims

claims

1. polymer fibers having microbicidal properties, comprising at least one electrospinnable polymer and nanoparticles comprising derivatized polyethyleneimine.

2. polymer fibers having microbicidal properties according to claim 1, characterized in that the derivatized polyethyleneimine comprises quaternized polyethylenimine.

3. polymer fibers having microbicidal properties according to claim 1 or 2, characterized in that the electrospinnable polymer is selected from the group poly (p-xylylene); Polyvinylidene halides, polyesters; Polyether; polyolefins; polycarbonates; polyurethanes; natural polymers; Polycarboxylic acids; polysulfonic; sulfated polysaccharides; polylactides;

polyglycosides; polyamides; Homopolymers and copolymers of aromatic vinyl compounds; Polyacrylonitriles, polymethacrylonitriles; polyacrylamides; polyimides; Polyphenylene; polysilanes; polysiloxanes; polybenzimidazoles; polybenzothiazoles; polyoxazoles; polysulfides; polyester; Polyarylene-vinylenes; polyether ketones; Polyurethanes, polysulfones, inorganic-organic hybrid polymers; silicones; wholly aromatic copolyesters; Poly (alkyl) acrylates; Poly (alkyl) methacrylates; polyhydroxyethylmethacrylates; Polyvinyl acetates, polyvinyl butyrates; polyisoprene; synthetic rubbers; polytetrafluoroethylene; modified and unmodified celluloses, homopolymers and copolymers of alpha-olefins and copolymers made up of two or more monomer units forming the abovementioned polymers; Polyvinyl alcohols, polyalkylene oxides, e.g. Polyethylene oxides; Poly-N-vinylpyrrolidone; hydroxymethylcelluloses; maleic; alginates; Collagen.

4. polymer fibers having microbicidal properties according to one of claims 1 to 3, characterized in that the nanoparticles quaternized polyethyleneimine of the general formula

wherein m, n are independently a natural number of 5 to 200, p is a natural number of 4 to 6, q is an integer of 0 to 11, and r is an integer of 0 to 4, and wherein

X = Br or I means included.

Polymer fibers having microbicidal properties according to one of claims 1 to 4, characterized in that the proportion of polyethyleneimine nanoparticles in the fibers is between 0.1% by weight to 25% by weight, preferably between 1.1% by weight and 13 wt%.

Polymer fibers having microbicidal properties according to one of claims 1 to 5, characterized in that the polymer fibers are electrospun.

Process for the preparation of microbicidal polymer fibers according to one of Claims 1 to 6, characterized in that the steps a) crosslinking of polyethyleneimine, b) alkylation of crosslinked polyethyleneimine, c) quaternization of secondary and tertiary amino groups of the polyethyleneimine, d) separation of the quaternized polyethylenimine nanoparticles, e) addition of the polyethylenimine nanoparticles to a solution of at least one electro-spinnable polymer, f) electrospinning of the solution containing polyethyleneimine nanoparticles of the at least one electro-spinnable polymer to fibers.

8. A process for producing polymer fibers according to any one of claims 1 to 6, characterized in that_die steps a) crosslinking of polyethyleneimine, b) alkylation of crosslinked polyethyleneimine, c) quaternization of secondary and tertiary amino groups of the polyethyleneimine, d) separation of the quaternized polyethylenimine Nanoparticles, e) electrospinning a solution of at least one electro-spinnable polymer into fibers f) covering the electrospun fibers with polyethyleneimine nanoparticles.

9. A process for the preparation of polymer fibers according to any one of claims 1 to 6, characterized in that the steps a) crosslinking of polyethyleneimine, b) alkylation of crosslinked polyethyleneimine, c) quaternization of secondary and tertiary amino groups of the polyethyleneimine, d) separation of the quaternized polyethyleneimine Nanoparticles, e) addition of the polyethylenimine nanoparticles to a solution of at least one electro-spinnable polymer, f) electrospinning of the polyethylenimine nanoparticles

Solution of the at least one electro-spinnable polymer into fibers g) Covering of the electrospun fibers with polyethyleneimine nanoparticles.

10. Use of microbicidal polymer fibers according to any one of claims 1 to 6 for the production of textile fibers and fabrics for functional clothing, protective clothing for medical personnel and protective clothing for patients, for medical drapes and wound dressings and / or for nonwovens or fiber mats for cell culture substrates