FI130889B1

FI130889B1 - A method of separating one or more polymer fractions from a material comprising textiles as well as specific polymer fractions and uses thereof

Info

Publication number: FI130889B1
Application number: FI20205756A
Authority: FI
Inventors: Mika Mänttäri; Ikenna Anugwom; Mari Kallioinen; Anastasiia Lopatina
Original assignee: Lappeenrannan Lahden Teknillinen Yliopisto Lut
Priority date: 2020-07-17
Filing date: 2020-07-17
Publication date: 2024-05-08
Also published as: FI20205756A1; WO2022013482A1

Abstract

The present invention relates to the fields of recycling textiles and treating materials comprising textiles or fibers thereof. Specifically, the invention relates to a method of separating one or more polymer fractions from a material comprising one or more textiles or fibers thereof. Still, the present invention relates to a product or fraction obtained by the method of the present invention and uses of said product or fraction.

Description

A method of separating one or more polymer fractions from a material com- prising textiles as well as specific polymer fractions and uses thereof

FIELD OF THE INVENTION

BACKGROUND OF THE INVENTION

Textile products are essential in our daily life, consequently, millions of tons of waste fabrics are generated every year. The increase in the production and consumption of textiles during the past few decades could also be attributed to the increasing worldwide population, improvements in living standards and the accelerating fash- ion cycle which demands more frequent replacement of the products with fresher, more modern ones. The current trends result in generation of more textile waste.

The quantity of waste textiles in the European Union (EU) is estimated to be 5.8 million tons per year. 25% of the textile waste is collected by charity organizations or businesses with the purpose of reusing or recycling and the rest of 5.8 million tons (i.e. about 4.3 million tons), is sent to landfills or municipal waste incinerators (Briga-Sa, A. et al. 2013, Construction and Building Materials. 38, 155-160). By 2030, total consumption of textiles is expected to have risen by 63%, from 62 million tons today to 102 million tons (Rengel, A.: Recycled Textile Fibres and Textile Re-

S cycling An overview of the Market and its possibilities for Public Procurers in Swit-

N zerland. Federal Office for the Environment (FOEN), Switzerland (2017)). The textile x industry's current linear model of make, use and disposal, represents an obvious

N 30 stress on natural resources. = > Currently, waste textile recycling is done either mechanically or chemically. Mechan-

O ical recycling is the simplest way to recycle fabrics, the process involves mechani-

S cally deconstructing the fabrics, ending up with re-useable fibers and material. It is

I 35 an effective way to bring used materials back into the cycle. However, the problem with this method is that natural fibers are shortened and damaged during the shred- ding process. This leads to reduction in their quality, and thus, their reusability is limited. Additionally, synthetic fibers also lose their guality and length every time going through a mechanical recycling process. For instance, if using regenerated cotton fibers, these would generally need to be fused with virgin cotton fiber threads to obtain the needed quality and strength — the mix often approximating 20% regen- erated fibers and 80% virgin. Furthermore, unfortunately, not all textiles are suitable for mechanical recycling, for example, pure cotton, pure polyester and textiles with high wool content.

Chemical recycling involves materials going through a chemical process to produce new filaments that will be transformed into new yarns and fabrics. So far, this recy- cling technique requires textiles consisting only of the same fiber to work efficiently and without complications. Furthermore, the reported chemical recycling methods often require harsh processing conditions resulting in low quality fiber, large amounts of chemicals for recycling and high amount of energy (see e.g. Negulescu,

Il. et al. 1998, Textile Chemist and Colorist. 30, 31-35). And significantly, the chem- ical recycling processes of the prior art fail to show the conversion of textile waste to new-value added products.

Reuses or recycling of products and materials will be impossible if there are no sim- ple, commercially acceptable separation processes for materials comprising textiles or fibers thereof (e.g. mixed fabrics waste). It is evident that there is a strong need to advance recycling methods of textile materials, towards a simple, effective, viable, and ecofriendly concept, that will comply with the circular economy ideology.

BRIEF DESCRIPTION OF THE INVENTION

Accumulation of large amounts of waste textile, e.g. waste poly-cotton fabrics (WP-

S CFs), leads to environmental challenges as well as depletion of resources. The pre-

N sent invention provides a solution to overcome the defects of the prior art including x but not limited to a lack of a simple, effective, cost-effective, viable and ecofriendly

N 30 concept for recycling materials comprising textiles thereby allowing a conversion of

I the textile material to new-value added products. The problems of the prior art down- > cycling of textiles, meaning production of materials of lower quality than the original

O material, can be overcome by the method of the present invention.

S

< 35 The objects of the invention, namely methods and tools for separating one or more polymer fractions from a material comprising textiles or fibers thereof, are achieved by utilizing a specific solvent with surprising effects e.g. on the separated fractions.

Indeed, it has now been found that a deep eutectic solvent (DES) can be effectively used in a surprisingly simple and large scale method for separating one or more polymer fractions from a material comprising textiles or fibers thereof (e.g. material comprising blended textiles). Indeed, in the present invention the structure of the textile can be affected or disintegrated by a composition comprising DES, for exam- ple in a way that at least part or all of the polymer fibers of the textile become sepa- rated from each other without being dissolved to said composition comprising DES and/or in a way that at least part of the polymer fibers become dissolved by said composition comprising DES. Thereafter one or more fractions containing an in- creased amount of components of interest, such as one or more solid fractions com- prising e.g. natural or synthetic polymers or polymer fibers, can be obtained. For example, the present invention enables obtaining or recovering one or more sub- stantially pure polymer fractions, e.g. having a very high degree of polymerization and/or a cellulose content. The technology of the present invention enables the use of waste textiles in order to generate new high quality fibers.

Furthermore, due to the effectiveness less chemicals are needed in the fractionation method of the present invention compared to the fractionation methods of the prior art. Also, the method of the present invention is suitable for a large-scale industrial separation of fractions.

Surprisingly the single, simple and effective fractionation method of the present in- vention enables separation of one or more or even all different types of natural (i.e. non-synthetic), semi-synthetic and/or synthetic polymers or fibers of the textile ma- terial. For example, upcycling of cotton and polyester from a mixed textile material is possible with the method of the present invention. The present invention enables

S recycling of different low-cost textile raw materials for further valorization.

O

N x The present invention relates to a method of separating one or more polymer frac-

N 30 tions from a material comprising one or more textiles or fibers thereof, wherein the

I material comprising one or more textiles or fibers thereof comprises semi-synthetic > and/or synthetic polymers or fibers, and said method comprises

O contacting the material comprising one or more textiles or fibers thereof with a com-

S position comprising a deep eutectic solvent (DES) to obtain a mixture of said mate-

I 35 rial and said composition, wherein the mixture comprises polymers or polymer fibers of the textile, which have been disintegrated from each other by the composition comprising DES, and wherein a ratio between the composition or DES and the ma- terial is from 30:1 to 2:1 by mass, and separating a first fraction comprising synthetic polymers or polymer fibers, the first fraction being a solid fraction, and a second fraction comprising polymers from the mixture (e.g. liquid part of the mixture).

Also, the present invention relates to a product or fraction comprising polymers or fibers, wherein said product or fraction is obtained by the method of the present invention for separating one or more polymer fractions from a material comprising textiles or fibers thereof.

And still, the present invention relates to use of the product or fraction of the present invention in industry, fabric or textile industry, membrane fabrication, biorefining, hy- drolysis into glucose or sugar derivatives, production of bioethanol, production of platform chemicals, or as platform chemicals.

Other objects, details and advantages of the present invention will become apparent from the following drawings, detailed description and examples.

BRIEF DESCRIPTION OF THE DRAWINGS

Figure 1 shows a schematic and an embodiment of the method of the present in- vention as well as fractions obtained by said method. The method of the present invention for separating one or more polymer fractions from a material comprising textiles or fibers thereof, is based on at least two steps i.e. contacting a material comprising textiles or fibers thereof with a composition comprising a deep eutectic solvent (DES) to obtain a mixture of said material and said composition, and sepa- rating a first fraction comprising at least one type of polymers (e.g. type one poly-

S mers) and/or a second fraction comprising at least one type of polymers (e.g. type

N two polymers) from the mixture.

S

N 30 Figure 2 shows a picture of the waste poly-cotton fabrics (WP-CFs) (A): before the

I NADES treatment, (B): after the NADES treatment and washing, (C): the recovered > cotton from the spent NADES and (D): the spent and fresh NADES.

O

S Figure 3 shows thermogravimetric analysis (TGA) curves of WP-CFs, before and

I 35 after the NADES treatment, and the recovered cotton precipitated by water.

Figure 4 shows Fourier transform infrared (FTIR) spectra of WP-CFs before and after the NADES treatment and the FTIR spectra of the recovered cotton after the treatment. Spectra A shows the whole range and spectra B shows ranges between 1900 to 400cm"!.

Figure 5 shows X-ray diffraction (XRD) spectra of the recovered cotton from the 5 spent NADES after the NADES treatment of WP-CFs for 6 hours at 120°C.

DETAILED DESCRIPTION OF THE INVENTION

The method of the present invention concerns textile recycling and valorization. The method of the present invention for separating one or more polymer fractions from a material comprising textiles or fibers thereof, is based on at least two steps i.e. contacting a material comprising textiles or fibers thereof with a composition com- prising a deep eutectic solvent (DES) to obtain a mixture of said material and said composition, and separating a first fraction comprising polymers (e.g. capable of remaining at least partly unaffected by the DES treatment) and/or a second fraction comprising polymers (e.g. at least partially affected by the DES treatment) from the mixture (see Figure 1). For example, solid polymers or polymer fibers of the mixture (e.g. having a larger size compared to the polymers of the optional second fraction) can be separated to the first fraction and/or smaller size polymers or polymer fibers such as (dispersed) natural polymers (e.g. cellulose) of the mixture can be sepa- rated to the second fraction.

Indeed, a composition comprising one or more DESs (or two or more said compo- sitions) is utilized with one or more different separation technologies to produce pu- — rified fractions from a material comprising textiles or fibers thereof (see figure 1).

The present invention thus provides a single method by combining DES treatment

S with one or more separation steps, and thereby enables synergistic effects, e.g.

N production of large amounts of substantially pure polymer fractions.

S

N 30 A material comprising textiles or fibers thereof to be used in the method of the pre-

I sent invention can be any material including but not limited to e.g. mixed waste or > mixed textiles. As used herein “a textile” refers to a material (e.g. flexible material)

O comprising a network of natural and/or artificial fibers (e.g. yarn or thread). For ex-

S ample, yarn can be produced by spinning fibers to long strands. Textiles can be

I 35 formed from fibers or yarn e.g. by weaving, knitting, crocheting, knotting, tatting, felting, twisting or braiding.

Majority of waste textiles are blended fibers because they often show a better per- formance than single-fiber textiles. Polyester and cotton are the most common syn- thetic and natural fibers, respectively, used in the world today. Polyester is a semi- crystalline thermoplastic polymer derived from petroleum-based chemicals which shows high tensile strength, chemical resistance, and is often thermally stable. As used herein a polyester refers to a polymer comprising an ester functional group in the main chain. An ester can be derived from an acid (organic or inorganic) in which at least one —OH (hydroxyl) group is replaced by an —O-alkyl (alkoxy) group. Poly- esters include naturally occurring polymers as well as synthetic and semi-synthetic polymers. In one embodiment the polyester is an aliphatic polyester, semi-aromatic polyester, aromatic polyester or copolymer.

Concerning cotton, the main component of the cotton fiber is a-cellulose molecule, and said molecules can count e.g. for 88.0-96.0 % by weight of the fibers, the rest being a mixture of proteins, waxes, pectins, inorganics, and other substances. Cel- lulose is a polysaccharide molecule consisting of a chain of anhydroglucose units, each containing three hydroxyl groups (-OH) with the molecular formula (C6H1005)n.

The anhydroglucoses are linked as repeating 3-cellobiose units. The positioning of the hydroxyl groups along the chain makes them readily available for hydrogen bonding. The strong hydrogen bonds formed between chains of the cellulose mole- cule result in a highly crystalline cotton fiber with a marked long and rigid structure known as a microfibril. (e.g. Morton, W.E., Hearle, W.S.: Physical properties of tex- tile fibers. Woodhead Publishing Limited (2008))

In one embodiment of the method of the present invention the material comprising one or more textiles or fibers thereof (or fabric) comprises natural, semi-synthetic

S and/or synthetic polymers or fibers. Textiles can be classified according to their fi-

R bers into silk, wool, linen, cotton, such synthetic fibers as rayon, nylon, and polyes- 3 ters, and some inorganic fibers, such as cloth of gold, glass fiber, and asbestos

N 30 cloth. In one embodiment the material comprising one or more textiles or fibers

I thereof comprises polymers or fibers selected from the group comprising or consist- > ing of cotton, wool, linen, silk, cellulose, polyester, acrylic, elastic, polypropylene

O (PP), polyethylene (PE), rayon, nylon, spandex, latex, carbon and vinyl polymers or

S fibers, and any combination thereof; or the material comprising textiles or fibers

I 35 thereof comprises cotton and polyester, cotton and elastic, cotton and wool, or cot- ton or wool polymers or fibers, or any combination thereof. In one embodiment the material comprising textiles or fibers thereof (or fabric) comprises cellulose and pol- yester polymers or fibers, or cellulose and polyester fabric blends.

In one embodiment the polyester can be any polyester e.g. suitable for use in textiles or can be selected e.g. from polyethylene terephthalate (PET), poly-i 4-cycio- hexylene-dimethylene (PCDT) and plant-based polyesters and any combination thereof. For example, plant-based paraxyiens, plant-derived ethyiene glycol, or bi- opolymers of molasses can be used for producing plant-based polyesters. For ex- ample, the textile to be treated according to the present invention can typically com- prise at least about 10%, 20%, 30%, 40%, 50%, or 60% or more (e.g. 100%) poly- esters (e.g. PET, PCDT and/or plant-based polyesters) by weight of the textile, e.g. about 10:90, 20:80, 30:70, 35:64, 45:54, or 50:50 other polymer (e.g. cotton): poly- ester by weight.

In one embodiment a tight combination of different types of polymers (e.g. a combi- nation of one or more polyesters and cotton) increases the difficulty of recycling.

The separation of blended fabrics can be based on the natural differences of said polymers.

The method of the present invention comprises separating a first fraction comprising polymers and/or a second fraction comprising (other) polymers (than in the first frac- tion) from the mixture comprising one or more textiles or fibers thereof and DES. In one embodiment one or more (e.g. one, two, three, four, five or more) types of nat- ural and/or synthetic polymers or fibers of the material are separated. In a specific embodiment all different types of natural and/or synthetic polymers or fibers present in the material to be treated can be separated or obtained with the method of the present invention.

S In the present invention the material comprising one or more textiles or fibers thereof

N (or e.g. small pieces of said material) is contacted with a composition comprising a x DES and thus a mixture of said material and said composition is obtained. Typically,

N 30 the treatment of the material with a composition comprising a DES is the first step

I of the fractionation method but does not need to be the first step. A solution com- > prising or consisting of one or more DESs can disintegrate or disentangle compo-

O nents of textiles or fibers thereof (e.g. different polymers from each other, e.g. syn-

S thetic polymers or polymer fibers and natural polymers such as cellulose from each

I 35 other), and thereafter separation of the polymers (e.g. one or more polyesters or other polymers) from the mixture or liquid part of the mixture is possible. Indeed, the composition comprising one or more DESs can separate or break bonds between components or polymers, e.g. between different polymer types (such as PET and cellulose, e.g. cellulose of cotton) of the textile. In one embodiment of the method of the present invention the mixture comprises polymers or polymer fibers of the textile, which have been disintegrated from each other by the composition compris- ing DES.

The composition of the present invention used for treating the material comprising one or more textiles or fibers thereof comprises a DES and optionally any other agent such as any other solvent, e.g. water or alcohol (such as ethanol, methanol, glycerol, carboxylic acids, guaindine hydrochloride). In one embodiment the compo- sition comprising DES is a liquid composition. In a specific embodiment the compo- sition consists of DES only.

As used herein DES refers to a deep eutectic solvent. DESs are a type of ionic liquid analogues formed from a eutectic mixture of Lewis or Bronsted acids and bases, i.e. a hydrogen bond acceptor (HBA) and a hydrogen bond donor (HBD). Compared to traditional ionic liquids DESs offer several advantages including their low toxicity, low price, and biodegradability. The physicochemical properties of DESs are similar to those of traditional ionic liquids. In general, the term DES is used to refer to a mixture of compounds at a ratio that is close to their eutectic point, i.e. where they form a mixture with lowest freezing (or melting) point. Typically, a DES is made up of two compounds, an HBA and an HBD, but in some cases a complexing agent may be required. In summary, the term “deep eutectic solvent” or acronym “DES” is used to describe a solvent which comprises two or more separate chemical com- pounds at a ratio that has the lowest melting point. Typically, DES is composed of a mixture of two or more organic compounds with a final melting point much lower than the individual components.

N

N Deep eutectic solvents are usually formed by mixing a hydrogen bond acceptor x (HBA) such as an ammonium, phosphonium, or sulfonium cation, and a hydrogen

N 30 bond donor (HBD) such as a carboxylic acid, a urea, or a glycerol. Exemplary cati-

I ons used include, but are not limited to, choline chloride, betaine, N-ethyl-2-hydroxy- > N,N-dimethylethanaminium chloride, 2-(chlorocarbonyloxy)-N,N,N-trimethylethana-

O minium chloride, and N-benzyl-2-hydroxy-N,N.dimethylethanaminium. Exemplary

S hydrogen bond donors include, but are not limited to, urea, acetamide, methylated

I 35 — ureas, glycerol, ethylene glycol, malonic acid, acetic acid, formic acid, lactic acid, adipic acid, oxalic acid, and citric acid. Examples of deep eutectic solvents include but are not limited to lactic acid : choline chloride (e.g. in the molar ratio 12:1 — 2:1, such as 9:1), acetic acid : choline chloride (e.g. in the molar ratio 18:1 — 2:1, such as 9:1), sorbitol : choline chloride (e.g. in the molar ratio 5:1 — 1:1, such as 5:1, 2:1 or 1:1), glycerol : choline chloride (e.g. in the molar ratio 5:1 — 1:1, such as 2:1), boric acid : choline chloride (e.g. in the molar ratio 3:1 — 1:1, such as 2:1), formic acid : choline chloride (e.g. in the molar ratio 1:1 — 3:1, such as 2:1), carboxylic acids choline chloride (e.g. in the molar ratio 3:1 — 1:1, such as 2:1), guaindine hydro- chloride : lactic acid (e.g. in the molar ratio 1:2 — 1:9, such as 1:10).

In a specific embodiment the DES is selected from the group consisting of natural deep eutectic solvents, choline chloride-based DESs, choline chloride/lactic acid, choline chloride/acetic acid, choline chloride/sorbitol/glycerol, choline chloride/boric acid, choline chloride/formic acid, and choline chloride/guanidine hydrochloride, and any combination thereof.

Choline chloride-based reagents are easy for high purity solvent preparation at sig- nificantly low capital expenditure.

When DES is prepared from reagents of natural origin or when the compounds that constitute the DES are primary metabolites, namely amino acids, organic acids, sugars, or choline derivatives, the DES is a so called natural deep eutectic solvent (NADES). In one embodiment the DES is a NADES. NADESs represents green chemistry principles and can be used in applications requiring principles of sustain- able development. NADESs do not present inherent toxicity and do not have high volatility, thus not leading to evaporation of volatile organic compounds to the at- mosphere.

In a very specific embodiment the material comprising poly-cotton fabrics (e.g. WP-

S CFs) is fractionated using NADES (e.g. based on a choline chloride and lactic acids

N solvent) in the solvent aided separation or recycling process of the present inven- x tion.

N 30

I In a specific embodiment the solution or DES choline chloride/lactic acid has a ratio > between choline chloride and lactic acid from 1:100 to 1:4 by molar mass, or at least

O 1:20 by molar mass, typically about 1:10 by molar mass.

S

< 35 In one embodiment of the invention, the composition comprising or consisting of

DES is contacted with the material at a ratio between the composition or DES and the material from 100:1 to 2:1 by mass, or at least 5:1 by mass, 10:1 by mass, 15:1 by mass, 20:1 by mass or 30:1 by mass.

In one embodiment the material is allowed to contact with the composition compris- ing DES for at least 30 minutes, 1 hour, 2 hours, 3 hours, 4 hours, 6 hours, or 2-25 hours or 3-10 hours, and/or the material is allowed to contact with said composition comprising DES at a temperature of at least 60°C, 70°C, 80°C, 90°C, 100°C, or 110°C; or less than 200°C, 190°C, 180°C, 170°C, 160°C, 150°C, 140°C, 130°C, 120°C, 110°C, 100°C, 90°C, 80°C or 70°C; or about 60 to 150°C or about 90 to 150°C. DESs enable extractions with low melting points, also below 100°C, making handling of DESs and the method of the present invention easy.

Optionally, physical treatment, such as increased pressure, microwave irradiation or ultra-sonication, of the material can be carried out when contacting the material with a composition comprising DES. These treatments typically decrease the treat- ment time needed in DES. In very specific embodiments when the physical treat- ment and DES treatment are combined, the material is allowed to contact with a composition comprising DES e.g. less than 2 hours.

Contacting the material with a composition comprising DES may be carried out e.g. by adding a DES composition to the material by one, two, three or several times or contacting the material with a DES composition one, two, three or several times.

In one embodiment after allowing the composition comprising DES to contact with the material, the liquid part of the obtained mixture comprises e.g. dissolved poly- mers, oligosaccharides, monosaccharides, solubilizers and/or other chemical agents or compounds dissolved from the treated material e.g. by DES, or any com- bination thereof, and/or undissolved components such as polymers and/or polymer

S fibers. The composition comprising DES enables disintegration of components, fi-

N bers or polymers of textiles from each other. Indeed, in one embodiment the material x is treated with a composition comprising a DES to remove or disintegrate at least a

N 30 portion of the polymers, e.g. natural and/or synthetic polymers, e.g. celluloses

I and/or other polymers such as synthetic polymers, from the material. a

O In one embodiment the method further comprises stirring or mixing the mixture (e.g.

S magnetic stirring or mixing) when the material is allowed to contact with the compo-

I 35 sition comprising a DES. In one embodiment the stirring or mixing is continued as long as the material is allowed to contact with the composition comprising a DES before a separation step.

In one embodiment after allowing the material to contact with the composition com- prising DES at an increased or high temperature, the obtained mixture is allowed to cool down e.g. to a room temperature before a separation step or the obtained mix- ture is used as a hot or warm mixture for a separation step.

In one embodiment of the invention at least one solid fraction comprising polymers or polymer fibers is separated from the mixture comprising textile or fibers thereof and DES and optionally dissolved compounds of the material. Indeed, in one em- bodiment after the material is allowed to contact with the composition comprising a

DES, the first fraction comprising polymers (of type one, e.g. undissolved or dis- solved polymers of the mixture) is separated from (the rest of) the mixture e.g. by a filtration (e.g. molecular or membrane filtration), centrifugal separation, decantation and/or pneumatic separation. As used herein “membrane filtration” refers to a tech- nique which is used to separate particles from a liquid for the purpose of purifying it, in other words a solvent and impurities are passed through a semi-permeable mem- brane. Membrane filtration techniques include nanofiltration, ultrafiltration, microfil- tration and reverse osmosis. In one embodiment the separation comprises filtration, optionally with a 300 — 400 um sieve opening, e.g. a 350 um sieve opening. The used size of sieve openings can depend on the type of the polymers of interest to be separated. Indeed, in one embodiment the first fraction comprising polymers is a solid polymer fraction. For example, synthetic polymer fibers such as PET fibers can be separated to the first polymer fraction. For example, cellulose (e.g. dispersed cellulose of cotton) cannot be separated with a sieve having large sieve openings (e.g. 300 — 400 um sieve openings), and therefore, in one embodiment of the inven- — tion a tighter filter is needed for separating celluloses.

S In one embodiment the first fraction comprises large solid polymer materials or fi-

N bers. In one embodiment when the material to be treated comprises synthetic poly- x mers, polyester or PET, then the first fraction comprises synthetic polymers, poly-

N 30 ester or PET, respectively. = > In one embodiment of the present invention after separating the first fraction from

O the mixture, the method further comprises washing the obtained first fraction (e.g.

S to remove residual DES), and/or drying said first fraction. Suitable washing temper-

I 35 atures include any temperature common to a person skilled in the art, for example below 100*C, below 40*C or e.g. about a room temperature (25*C). Suitable drying conditions include but are not limited to e.g. 60*C — 100°C (e.g. 80°C) for 2 — 10 hours (e.g. 6 h).

In one embodiment the yield of the polymers or fibers of the first fraction is at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98% or 99%, and/or the purity of the polymers or fibers of the first fraction is at least 90%, 91%, 92%, 93%, 94%, 95%, 95.5%, 96%, 96.5%, 97%, 97.5%, 98%, 98.5%, 99% or 99.5%.

After removing the first fraction from the mixture or without removing the first fraction from the mixture, the method of the present invention can comprise adding aqueous liquid such as water (e.g. deionized water) or another solvent to the mixture (option- ally obtained after separating the first fraction comprising polymers from the mix- ture). Indeed, in one embodiment before separating the second fraction comprising polymers, water or another solvent is added to the mixture (optionally obtained after separating the first fraction comprising polymers from the mixture). Addition of water or another solvent can be used e.g. in cases wherein one or more of the polymers or fibers to be separated from the mixture are dissolved polymers. For example in such cases precipitation of polymers can be enhanced, induced or carried out by adding said aqueous liquid (e.g. water) to the mixture, and optionally thereafter the second fraction of the mixture comprising polymers can be obtained.

In one embodiment water or another solvent is not added to the mixture (which is optionally obtained after separating the first fraction comprising polymers from the mixture) before separating the second or further fraction comprising polymers. In- deed, in one embodiment the second polymer fraction can be separated (directly) from the mixture comprising or consisting of one or more textiles or fibers thereof and a composition comprising DES, i.e. without any addition of water or another solvent to the mixture.

N

N In one embodiment the method comprises separating the second fraction compris- x ing polymers (undissolved or dissolved polymers) from the mixture (optionally ob-

N 30 tained after separating the first fraction comprising polymers from the mixture). In

I cases wherein both the first and the second fractions are separated in the method > of the present invention, separation can be carried out e.g. based on different sizes

O of the components, fibers or polymers of interest. For example, large solid polymers,

S polymer fibers or polymer materials of the mixture can be separated as the first

I 35 fraction and smaller polymers such as dispersed cellulose of the mixture as the sec- ond fraction.

In one embodiment the second fraction is separated by a centrifugation, gravity sep- aration, membrane aided separation and/or filtration, typically by a combination of a centrifugation, gravity separation, or membrane aided separation, and a filtration (optionally after adding the aqueous liquid (e.g. water) or other solvent to the mixture or without addition of said aqueous liquid or solvent). In one embodiment the sepa- ration comprises filtration, optionally with a 0.3 — 0.5 um pore size filter, e.g. a 0.45 um pore size filter. The used pore size can depend on the type of the polymers of interest to be separated. In one embodiment the pore size of the filter or sieve for separating the second fraction is smaller compared to the pore size of the filter or sieve used for separating the first fraction, thereby allowing separation of compo- nents of different sizes from the mixture, e.g. large synthetic or natural polymers or materials to the first fraction and smaller polymers or materials, e.g. dispersed syn- thetic or natural polymers such as cellulose, to the second fraction.

In a very specific embodiment, one or more polymers or polymer fibers of the textile disintegrated from each other by the composition comprising DES without being dissolved to said composition comprising DES are separated e.g. at least by filtering to at least two fractions, wherein the first fraction can comprise e.g. large solid pol- ymers or fibers such as synthetic polymers or fibers e.g. PET and the second frac- — tion can comprise smaller polymers or polymer fibers compared to the first fraction, e.g. dispersed cellulose.

For example, the present invention enables extraction of microcrystalline cellulose from a material comprising textiles or fibers thereof by utilizing DES. The extraction of microcrystalline cellulose as value-added products can be utilized in the present invention e.g. for recycling material comprising cotton or material comprising poly-

S ester cotton blended textile. In one embodiment when the material to be treated

N comprises natural polymers, cellulose or cotton (e.g. a combination of a polyester x or PET, and cotton) the second fraction comprises natural polymers, cellulose or

N 30 cotton (e.g. cellulose of cotton). = > In one embodiment the second fraction or the polymers or fibers of the second frac-

O tion are washed e.g. to remove residual DES, and/or dried. Suitable washing tem-

S peratures include any temperature common to a person skilled in the art, for exam-

I 35 ple below 100°C, below 40°C or e.g. about a room temperature (25°C). Suitable drying conditions include but are not limited to e.g. 60°C — 100°C (e.g. 80°C) for 2 — 10 hours (e.g. 6 h).

In one embodiment the yield of the polymers or fibers of the second fraction is at least 60%, 65%, 70%, 75%, 80%, 85%, or 90%; the purity of the polymers or fibers of the second fraction is at least 90%, 91%, 92%, 93%, 94%, 95%, 95.5%, 96%, 96.5%, 97%, 97.5%, 98%, 98.5%, 99% or 99.5%; and/or the degree of polymeriza- tion in the second fraction is at least 200, 210, 220, 230, 240, 250, 260, 270, 280, 290, 300, 310, 320, 330, 340, 350, 360, 370, 380, 390 or 400, typically 200 — 600 or 200 — 500. Indeed, for example production of large amounts of substantially pure cellulose, e.g. having high degree of polymerization is possible by the method of the present invention.

In one embodiment the purity of the polymers or fibers of the second fraction is at least 90%, 91%, 92%, 93%, 94%, 95%, 95.5%, 96%, 96.5%, 97%, 97.5%, 98%, 98.5%, 99% or 99.5%, and the degree of polymerization in the second fraction is at least 200, 210, 220, 230, 240, 250, 260, 270, 280, 290, 300, 310, 320, 330, 340, 350, 360, 370, 380, 390 or 400, typically 200 — 600 or 200 — 500. For example, extraction of cellulose from the textile material and thereafter separation of micro- crystalline cellulose is enabled by the present invention. In one embodiment the cellulose (or cotton) purity and degree of polymerization of the second fraction is at least 95% (e.g. at least 98%) and at least 200 (e.g. at least 220), respectively.

The degree of polymerization can be determined by any suitable method e.g. the

CED method as described in the article of Shi, S. et al. (2018, Waste Management. 82, 139-146) or Zhang, H. et al. (2016, Physical Chemistry Chemical Physics. 18, 28297-28306). For example, one or more of the following equations can be used to calculate the degree of polymerization:

N Relative viscosity nr can be calculated by equation 1.

N

S Eguation 1 ,

S 30 n, = - = = > Where: © t= flow time of solutions 5 to= flow time of solvent < 35 n%= zero shear viscosity of solutions

S ns= zero shear viscosity of solvent

Specific viscosity nsp was calculated using equation 2.

Equation 2

Nsp = n 1 =

The intrinsic viscosity [n] can be determined by the equation 3.

Equation 3 [20nsp — Inn.) ””] [n] = — AA

Where: C= concentration

The degree of polymerization (DP) can then be calculated by the relationship built by Liu, J. et al. (2016, Cellulose. 23, 2341-2348) which is suitable for samples with

DP values in the range of 220 to 1400 (equation 4).

Equation 4

DP = 134[n]'?

In one embodiment of the present invention, e.g. as shown in the examples of the present disclosure, the solubility of obtained cellulose is reduced with increasing DP.

In one embodiment the degree of crystallization of the polymers of the second frac- tion (e.g. cellulose or cotton) can be e.g. at least 80%, 85%, 90%, or 95%. The degree of crystallization can be determined by any suitable method, e.g. X-ray dif- fraction (XRD). For example, suitable XRD patterns are presented in Figure 5. In + one embodiment the cellulose or cotton of the second fraction exhibits crystalline

S patterns that are typical for either native cellulose or cotton. For example, high crys- <+ tallinity index values can indicate the removal of the amorphous regions after the = NADES treatment. Furthermore, the crystallinity index value can also indicate a high - 30 rigidity of the recovered cellulose or cotton. 7 © For example, the first or second fraction (e.g. cotton isolated from the material com- 5 prising textiles such as polyester cotton blended fabric) can be characterized by its

O structure, crystallinity, degree of polymerization (DP), and/or thermal stability e.g. as shown in the examples part of the present disclosure. For example, scanning elec- tron microscopy (SEM), X-ray diffraction (XRD), Fourier transform infrared (FT-IR), thermogravimetric analysis (TGA) and/or contact angle analysis can be utilized for characterizing the fractions, e.g. as shown in the examples part of the present dis- closure.

In one embodiment after separating one or more fractions (e.g. the first and/or sec- ond fraction) from the mixture the DES is separated from the remaining mixture, and optionally purified, for reuse. For example, water, if used in said mixture, can be evaporated from the mixture before recovering the DES for further use.

In one embodiment at least a portion of the polymers or fibers of the first and/or second fraction is directed to further processing or for use in industry, e.g. fabric or textile industry, membrane fabrication, biorefining, hydrolysis into glucose or sugar derivatives, production of bioethanol, production of platform chemicals, or as plat- form chemicals.

The present invention also concerns a product or fraction (e.g. the first and/or sec- ond fraction) comprising polymers or fibers, wherein said product or fraction is ob- tained by the method of the present invention. In one embodiment the product can be a combination of one or more fractions or polymers, e.g. a combination of the first and the second fraction. Said combination can be a mixture of said fractions or polymers, or any non-mixed combination.

In one embodiment the product or fraction is a washed and/or dried product or frac- tion. The product or fraction can be in any solid, semi-solid or liquid form, such as in a form of a solution, suspension, pellet or powder.

In one embodiment the degree of polymerization in the product or fraction (e.g. the

S first and/or second fraction) is at least 200, 210, 220, 230, 240, 250, 260, 270, 280,

N 290, 300, 310, 320, 330, 340, 350, 360, 370, 380, 390 or 400, typically 200 — 600 x or 200 — 500; the yield of the polymers or fibers (e.g. of the first and/or second

N 30 fraction) is at least 60%, 65%, 70%, 75%, 80%, 85%, or 90%, or at least 90%, 91%,

I 92%, 93%, 94%, 95%, 96%, 97%, 98% or 99%; and/or the purity of the polymers or > fibers (e.g. of the first and/or second fraction) is at least 90%, 91%, 92%, 93%, 94%,

O 95%, 95.5%, 96%, 96.5%, 97%, 97.5%, 98%, 98.5%, 99% or 99.5%.

S

< 35 The present invention further concerns use of the product or fraction of the present invention in industry, fabric or textile industry, membrane fabrication, biorefining, hy- drolysis into glucose or sugar derivatives, production of bioethanol (e.g. via enzy- matic hydrolysis), production of platform chemicals, or as platform chemicals. In one embodiment, the polymers or any fraction of the present invention can be dissolved and respinned into a fibric or textile. For example, microcrystalline cellulose (MCC) can be produced by the present invention and broadly applied in packaging, agri- culture, food, automotive, aerospace, and other industries.

Waste textiles, such as fabrics comprising polyester and/or cotton, are valuable re- sources worthy of recycling and the present invention provides methods and tools suitable for said recycling.

It will be obvious to a person skilled in the art that, as the technology advances, the inventive concept can be implemented in various ways. The invention and its em- bodiments are not limited to the examples described below but may vary within the scope of the claims.

EXAMPLES

Materials

Waste poly-cotton fabrics (WP-CFs) were purchased from the local retail store, the polyester cotton ratio was 65:35 weight ratio was reported by manufacturer. Choline chloride (ChCI) (CAS # 67-48-1, Merck KGaA, Darmstadt, Germany) was used as

HBA and lactic acid (LAc) (CAS # 79-33-4, Merck KGaA, Darmstadt, Germany) as

HBD. Ultra-pure deionized water (DI, 15 MW) was obtained from a CENTRA-R 60/120 system (Elga purification system, Veolia Water, Bucks, UK), and used in all experiments. In this experiment all the reagents were analytically pure and used without pretreatment. However, any reagents including e.g. analytically impure 5 and/or pretreated reagents suitable for large scale industrial methods can be used

N in the present invention. All the experiments were replicated twice only for scientific

S purposes.

N 30

I NADES Preparation a

O The preparation of NADES was implemented by the mixture of choline chloride and

S lactic acid at the molar ratio of 1:10, followed by rigorous agitation for 2 h at 85°C.

I 35 Once a homogeneous and transparent liguid without a presence of solid particles was achieved, the resulting clear liguid was laid aside in a desiccator at room tem- perature to be cooled gradually without any moisture absorption.

Fractionation of WP-CFs

NADES aided fractionation of WP-CFs was carried out in a pressure-resistant glass container. The WP-CFs were cut into small pieces (1x1 cm?), and each dry sample (2.0 g) was mixed with NADES and heated to the desired temperature (100-130°C) with different solvent to WP-CFs ratio. Heating was provided on a hotplate equipped with magnetic stirred, an oil bath was used to ensure homogenous heating during the treatment period. After that, the mixture was filtered through a 350 um size filter mesh to separate the lager particles (polyester) from NADES solution enriched with cotton macromolecules. Then the polyester was washed with distilled water, finally, it was dried at 80°C for 6 h to obtain a product. The cotton rich spent NADES was then mixed with DI water to induce the precipitation of cotton, which was then sep- arated by centrifugation and decantation. The water was evaporated using rotary evaporator, to recover the spent NADES for reuse.

Characterization

Acid hydrolysis

The cotton and polyester content were determined according to the EU regulation no. 1007/2011. All blended fabrics were treated in a 10M H2SO4 solution at 95°C between 20-30 min with a liquor to sample ratio of 100:0.2 to ensure complete dis- solution of the cellulose component. Then, the mixture was poured into ice water to quench the reaction. The polyester residue was filtered off, washed with water and acetone, and dried in a vacuum oven for 6 h at 50°C. The resulting weights were compared to the initial blend concentration. The dry matter content of the starting materials and the resulting products was included in the calculation (REGULATION a (EU) No 1007/2011 OF THE EUROPEAN PARLIAMENT AND OF THE COUNCIL,

N https://eur-lex.europa.eu/legal-content/EN/TXT/HTML/?uri=CELEX:02011R1007- 3 20130701&from=EN, (2011)).

N 30

I Determination of the DP, yield of recovered cotton and residual amount of WP-CFs > The DP of the recovered cotton from the NADES fractionation process was investi-

O gated to determine the effect of the treatment conditions on the macromolecular

S cellulose chains. The DP was determined by the CED method (Shi, S. et al. 2018,

I 35 Waste Management. 82, 139—146; Zhang, H. et al. 2016, Physical Chemistry Chem- ical Physics. 18, 28297-28306). Approximately 3 g of recovered cotton was added to 50 mL stoppered bottles containing 7.5 mL distilled water and ultrasonicated for 2 min to obtain wet powder. Then 22.5 mL 1.0 M CED at aratio of 3:1 was added to the bottle. The mixture was shaken until the recovered cotton dissolved. The DP of the recovered cotton is calculated using the following equations.

Equations used to calculate degree of polymerization

Relative viscosity nr was calculated by equation 1.

Equation 1 tom

Tr = to Ns

Where: t= flow time of solutions to= flow time of solvent nP= zero shear viscosity of solutions — ns= zero shear viscosity of solvent

Specific viscosity nsp was calculated using equation 2.

Equation 2 n°

Nsp = n -1

The intrinsic viscosity [n] was determined by the eguation 3.

Equation 3 [2 (Msp - inn.)

[1] = — AA

Where: C= concentration <

N The DP was then calculated by the relationship built by Liu, J. et al. (2016, Cellulose. 5 23, 2341-2348) which is suitable for samples with DP values in the range of 220 to ? 30 1400 (equation 4).

S

E Eguation 4

O

O 1.2 5 DP = 134[n]

N Fourier Transform Infrared Spectroscopy

To characterize the NADES treated and untreated WP-CFs, FTIR spectra of the recovered materials were measured by using a Perkin Elmer Frontier spectrometer with a universal ATR module (Diamond crystal). FTIR spectra of three random spots from each fibers sample were measured in the 4000-400 cm”! wavenumber range with the resolution of 4 cm". All spectra were the acquisition of 4 scans with the data interval of 1 cm at the absorbance mode. At the final step, the co-added spectra were processed with ATR correction and baseline correction, and finally normalized.

Scanning Electron Microscopy

The morphology of the NADES treated and untreated WP-CFs were studied quali- tatively with a scanning electron microscope (Hitachi SU 3500, Tokyo, Japan) at the acceleration voltage of 15 kV in a high vacuum condition. The NADES treated and untreated WP-CFs samples were coated with a thin layer of gold by using the Ed- wards Scancoat six Pirani 501 sputter coating system (Edwards High Vacuum In- ternational, Crawley, UK).

Thermogravimetric analysis

For thermogravimetric analysis, approx. 10£0.1 mg of the specimen was heated from 25°C to 900°C at a rate of 10°C/min under a nitrogen atmosphere of 40 mL/min nitrogen at a constant flow rate. Evolved gas emission (EGA) during TGA was ana- lyzed using a mass spectrophotometer (MS 403C Aé&olos Mass Spectrophotometer,

NETZSCH-Gerätebau GmbH, Selb, Germany) which was coupled with TGA. The analyzed mass range was 10-110 a.m.u. The results were interpreted with N-Pro- teus® software (NETZSCH-Gerätebau GmbH, Selb, Germany).

X-ray diffraction measurements

To reveal any changes in Cotton (cellulose) recovered from the NADES aided sep- aration of cotton from polyester in WP-CFs, the crystallinity of the recovered material

S was analyzed with an X-ray diffraction (XRD) device (Bruker AXS D8 Advance X-

N ray diffractometer). The X-ray diffraction patterns were obtained using Cu Ka (A = x 1.5418 A) at 40 kV and 40 mA in the range of 20 = 7 — 60°. To estimate the relative

N 30 degree of crystallinity of the cellulose, a crystallinity index (Crl) was calculated based

I on the XRD patterns using the relationship given by Segal, L. et al. (1959, Text Res > J. 29: 786-794) in the following Eq. (3):

O

5 Cr] = Vaa x 100

S where Crl — crystallinity index, lio: — intensity at about 20 = 22° (represents the crys- talline and amorphous material), lan — intensity at the “valley” between the two main peaks at about 26 = 18° (represent the amorphous material).

Results and discussion

Figure 2 shows the steps of the schematic for WP-CFs separation process. The

WP-CFs (Fig. 2a) cut into 1 x1 cm pieces and NADES treated WP-CFs (mainly pol- yester fraction) (Fig. 2b), and then the recovered cotton from spent NADES after treatment (mainly the cotton fraction) (Fig. 2c). Spent NADES after water evapora- tion ready for reuse and Fresh NADES before the treatment of WP-CFs (Fig. 2d).

Effect of the reaction time and NADES-WP-CFs Ratio

The effect of NADES-WP-CFs ratio on the efficiency on separation of cotton from polyester, was investigated at 120°C, for 6-hours, NADES treatment using 4 differ- ent NADES-WP-CFs ratios, from 5:1 until 20:1. Table 1 shows that there are no significant differences between the separation efficiencies regarding the different ratios. Slight difficulties to achieve complete mixture or to ensure that all of the textile materials were properly covered with the solvent, when the solid to solvent ratio was low (1:5), were overcome by rigorous shaking of the flask before the start of the treatment. These difficulties were not faced when the solid to solvent ratio increased.

Thus, the need for more solvent for the treatment was considered for subsequent experiments. However, there is a big change in the separation efficiency of WP-CFs when the treatment time was only 4h at 120°C compared to the treatment time for 6h at 120°C. There was 4% less weight reduction of the WP-CFs when the treatment time was 4 h (26wt-%) while the weight reduction was 30 % when the treatment time was extended to 6h treatment using the same ratio (20:1 ratio) for both treatments.

Table 1. The effect of WP-CFs/NADES ratio on the separation efficiency of WP-

N CFs.

N Sample Starting Ending weight loss 3 weight weight (20)

N A: 1: 5 (weight ratio) at 120°C for | 10.0+0.1 7.24+0.9 28 6h = > B: 1: 10 (weight ratio) at 120°C | 10.0+0.1 7.18+0.3 28.2

O for 6 h

N

& C: 1: 15 (weight ratio) at 120°C | 10.0+0.1 7.01+2.1 30

Al

O for6h

Al

D: 1: 20 (weight ratio) at 120°C | 10.0£0.1 7.00+1.1 30 for6h

Efficiency of NADES aided separation of WP-CFs

To determine the cotton and polyester contents in blended materials, a degradation of cellulose to water-soluble degradation products was carried out. Consequentially, the residual polyester remained unaffected by the acid hydrolysis and could thus be separated easily yielding reliable information on the true blend concentration. The dry matter content can be taken into consideration when determining the blend con- centration, since polyester tends to adsorb less moisture than cotton. Treatment times and acid concentrations were therefore adjusted in a way to ensure a com- plete dissolution of the cotton component. The cellulose content of the NADES treated WP-CFs is presented in Table 2.

Table 2. Efficiency of NADES aided separation of WP-CFs.

Sample Polyester Cellulose content, % content, %

A: Waste polyester-cotton blend fabrics (WP- | 6513.1 3512.1

CFs)

B: NADES treatment at 120°C for 6h 9310.1 4.24+0.9

C: NADES treatment at 120°C for 4h 90+0.1 8.18+0.3

D: cotton recovered from NADES after the treat- | 0.05+0.2 98.2+2.1 ment after 6h

E: cotton recovered from NADES after the treat- | 0.9+0.1 98.03+1.1 ment after 4h

Thermogravimetric analysis (TGA) a The TGA curves of the WP-CFs are presented in Figure 3. As shown in Figure 3,

N the whole decomposition process of all three blends could be divided into two parts. 3 The first part starts at around 310°C and ends at approximately 380—390*C, corre-

N sponding to the decomposition of the cotton component in the blends, and the sec-

I 20 ond part continues from there until 470—485*C, corresponding to the decomposition > of the polyester component. The WP-CFs had about 17% of its initial weight loss at

O the point when the first decomposition stage ended. The second range in the TGA 3 diagram of the WP-CFs had a gentler downward progression and then tended to a

Al

S rapid decline afterwards. More char is produced with a higher polyester content con- tained in the fabrics.

FT-IR Analysis of the WP-CFs before and after the NADES treatment

FT-IR spectroscopy was used to confirm the functionality of the WP-CFs, before and after the NADES treatment, and the cotton recovered from the spent NADES. The

FT-IR spectra of all samples are illustrated in Figure 4. The broad band at 3300 cm” ! attributed to the OH absorption is very prominent in the spectra of the recovered cotton and the untreated WP-CFs indicating the presence of cotton in the untreated

WP-CFs. Furthermore, the C-H stretching frequency appeared at 2900 cm”, and the freguencies at 1650, 1064, and 1383 cm"! are attributed to the C=O stretching,

C-O-C glycosidic bond and the bonding of CHz, respectively (Punnadiyil, R.K. et al. 2016, J. Chem Pharm. Sci. 12—16). Also, the absorbance peaks of cellulose B-gly- — cosidic linkage were observed at 894 cm”, all these spectral data reveal that the precipitated solid materials from the spent NADES have similar characteristic ab- sorption peaks than pure cotton(cellulose), indicating the selective removal of cotton from WP-CFs by NADES treatment. The IR signal of residual polyester from the

NADES treatment of WP-CFs process can be seen in two absorption bands in the range between 1150 and 1250 cm”, and 1715-1740 cm”, as well at 718 cm"! in

Figure 4. The first band was assigned to the C-O stretch, and the second to the C=O stretch, both from the ester bonds in the polyester, these are mostly present in both the untreated and the recovered solid samples after the NADES treatment of WP-

CFs.

X-ray diffraction

The crystalline structure of recovered cotton (cellulose) from the spent NADES, after the treatment of WP-CFs was studied by XRD. The XRD patterns is presented in

Figure 5. The samples exhibited similar crystalline patterns that are typical for either native cotton or cellulose. For the XRD patterns of recovered cotton, a typical cellu- lose | structure was defined by the reflections at 20 values of at 14.9°, 22.2° and

S 34.5°, corresponding to the (1 O 1), (0 O 2), and (O 4 O) crystallographic planes,

N respectively (Leppänen, K. et al. 2009, Cellulose. 16, 999—1015). The crystallin- x ity of recovered cotton was found to be 85.32. The crystallinity index value is some

N 30 worth high, indicating the removal of the amorphous regions after the NADES treat-

I ment. Furthermore, the crystallinity index value also suggests that the recovered > cotton exhibits a high rigidity (Shi, S. et al. 2018, Waste Management. 82, 139-146;

O Leppänen, K. et al. 2009, Cellulose. 16, 999—1015).

S

< 35 Degree of Polymerization of Cotton

The effects of NADES on the DP of the recovered cotton were evaluated in the separation process of the present invention. The solubility of cellulose reduced with increasing DP, thus, this giving a clear indication why herein we did not achieve dissolution but rather separation or breakage of the bond between the different pol- ymer types (cotton and PET) of the cellulose fraction within the WP-CFs. The DP of the recovered cotton from the NADES was 250. Mainly the crystalline area, any possible amorphous area of the cellulose, was hydrolyzed, thus decreasing the DP and yield decrease could be attained upon prolonging the pretreatment time.

Conclusion

Cotton and Polyester (PET) were successfully separated from waste polyester cot- ton blended fabric (WP-CFs) by a novel method based on a DES (e.g. NADES) assisted procedure. Two pure fractions of polyester and cotton were obtained, and the obtained cotton fraction had a cellulose content and DP of 98.2% and 228, re- spectively. The results presented in the examples of the present disclosure show that the method of the present invention is suitable and effective for recycling waste fabrics towards the recovery of one or more pure fractions or polymers (e.g. cotton and PET) of said fabrics. The method is suitable for different textile materials and pure fractions of polymers can be obtained with a non-toxic solvent under mild con- ditions such as a low temperature and considerable time. <

N

O

N

< <Q

N

O

I

=

O

LO

N

LO

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Al oo

Al

Claims

1. A method of separating one or more polymer fractions from a material com- prising one or more textiles or fibers thereof, wherein the material comprising one or more textiles or fibers thereof comprises semi-synthetic and/or synthetic polymers or fibers, and said method comprises contacting the material comprising one or more textiles or fibers thereof with a composition comprising a deep eutectic solvent (DES) to obtain a mixture of said material and said composition, wherein the mixture comprises polymers or polymer fibers of the textile, which have been disintegrated from each other by the composi- tion comprising DES, and wherein a ratio between the composition or DES and the material is from 30:1 to 2:1 by mass, and separating a first fraction comprising synthetic polymers or polymer fibers, the first fraction being a solid fraction, and a second fraction comprising polymers from — the mixture.

2. The method of claim 1, wherein the material comprising textiles or fibers thereof comprises polymers or fibers selected from the list comprising or consisting of cot- ton, wool, linen, silk, cellulose, polyester, acrylic, elastic, polypropylene (PP), poly- ethylene (PE), rayon, nylon, spandex, latex, carbon and vinyl polymers or fibers, and any combination thereof; or the material comprising textiles or fibers thereof comprises cotton and polyester, cotton and elastic, cotton and wool, or cotton or wool polymers or fibers, or any combination thereof.

3. The method of claim 2, wherein the polyester is selected from polyethylene ter- ephthalate (PET), poly-1,4-cyclohexylene-dimethylene (PCDT) and plant-based 2 polyesters. &

N 4. The method of any of the preceding claims, wherein the material is allowed to ~ 30 contact with said composition comprising DES for at least 30 minutes, 1 hour, 2 I hours, 3 hours, 4 hours, or 2-25 hours or 3-10 hours. a

O 5. The method of any of the preceding claims, wherein the material is allowed to S contact with said composition comprising DES at a temperature of at least 60°C, I 35 70°C, 80°C, 90°C, 100°C, 110°C, or less than 200°C, 190°C, 180°C, 170°C, 160°C, 150°C, 140°C, 130°C, 120°C, 110°C or 100°C, or about 60 to 150°C or about 90 to 150°C.

6. The method of any of the preceding claims, wherein the method further comprises stirring or mixing the mixture.

7. The method of any of the preceding claims, wherein DES is selected from the group consisting of natural deep eutectic solvents, choline chloride/lactic acid, cho- line chloride/acetic acid, choline chloride/sorbitol/glycerol, choline chloride/boric acid, choline chloride/formic acid, and choline chloride/guanidine hydrochloride, and any combination thereof.

8. The method of claim 7, wherein DES choline chloride/lactic acid has a ratio be- tween choline chloride and lactic acid from 1:100 to 1:4 by molar mass, or at least 1:20 by molar mass, typically about 1:10 by molar mass.

9. The method of any of the preceding claims, wherein the first fraction comprising polymers is separated from the mixture by a filtration, centrifugal separation, de- cantation and/or pneumatic separation.

10. The method of any of the preceding claims, wherein the first fraction comprises polyester or PET when the material comprising textiles or fibers comprises polyester or PET, respectively.

11. The method of any of the preceding claims, wherein polymers or fibers of the first fraction are washed to remove residual DES.

12. The method of any of the preceding claim, wherein the yield of the polymers or D fibers of the first fraction is at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, N 98% or 99%, and/or the purity of the polymers or fibers of the first fraction is at least S 90%, 91%, 92%, 93%, 94%, 95%, 95.5%, 96%, 96.5%, 97%, 97.5%, 98%, 98.5%, n 30 99% or 99.5%. = >

13. The method of any of the preceding claims, wherein before separating the sec- O ond fraction comprising polymers, water or another solvent is added to the mixture, S which is optionally obtained after separating the first fraction comprising polymers I 35 from the mixture; or wherein water or another solvent is not added to the mixture before separating the second fraction comprising polymers.

14. The method of any of the preceding claims, wherein the second fraction com- prising polymers is separated by a centrifugation, gravity separation, membrane aided separation, and/or filtration, typically by a combination of a centrifugation, gravity separation or membrane aided separation, and a filtration.

15. The method of any of the preceding claims, wherein the second fraction com- prises natural polymers, cellulose or cotton when the material comprising textiles or fibers comprises natural polymers, cellulose or cotton.

16. The method of any of the preceding claims, wherein polymers or fibers of the second fraction are washed to remove residual DES.

17. The method of any of the preceding claims, wherein the yield of the polymers or fibers of the second fraction is at least 60%, 65%, 70%, 75%, 80%, 85%, or 90%; the purity of the polymers or fibers of the second fraction is at least 90%, 91%, 92%, 93%, 94%, 95%, 95.5%, 96%, 96.5%, 97%, 97.5%, 98%, 98.5%, 99% or 99.5%; and/or the degree of polymerization in the second fraction is at least 200, 210, 220, 230, 240 250, 260, 270, 280, 290, 300, 310, 320, 330, 340, 350, 360, 370, 380, 390 or 400, typically 200 — 600 or 200 — 500.

18. The method of any of the preceding claims, wherein after separating the first and/or second fraction comprising polymers the DES is separated from the mixture, and optionally purified, for reuse.

19. The method of any of the preceding claims, wherein at least a portion of the D polymers or fibers of the first and/or second fraction is directed to further processing N or for use in industry. S ~ 30

20. A product or fraction comprising polymers or fibers, wherein said product or I fraction is obtained by the method of any of claims 1-19. a O

21. The product or fraction of claim 20, wherein the degree of polymerization in the S product or fraction is at least 200, 210, 220, 230, 240, 250, 260, 270, 280, 290, 300, I 35 310, 320, 330, 340, 350, 360, 370, 380, 390 or 400, typically 200 — 600 or 200 —

500.

22. The product or fraction of claim 20 or 21, wherein the yield of the polymers or fibers of the first fraction is at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98% or 99%, and/or the purity of the polymers or fibers of the first fraction is at least 90%, 91%, 92%, 93%, 94%, 95%, 95.5%, 96%, 96.5%, 97%, 97.5%, 98%, 98.5%, 99% or 99.5%; and/or the yield of the polymers or fibers of the second fraction is at least 60%, 65%, 70%, 75%, 80%, 85%, or 90%, and/or the purity of the polymers or fibers of the second fraction is at least 90%, 91%, 92%, 93%, 94%, 95%, 95.5%, 96%, 96.5%, 97%,

97.5%, 98%, 98.5%, 99% or 99.5%.

23. Use of the product or fraction of any of claims 20-22 in industry, fabric or textile industry, membrane fabrication, biorefining, hydrolysis into glucose or sugar deriva- tives, production of bioethanol, production of platform chemicals, or as platform chemicals. O N O N N <Q Nn I = O LO N LO O Al oo Al