Selective solvation of target polymers from a textile mixture within pressurizable systems

Abstract

Methods for selectively or successively recovering target polymers, including polyesters and nylons, for a textile blend by regulating the temperature and pressure of a single-component solvent are provided.

Description

SELECTIVE SOLVATION OF TARGET POLYMERS FROM A TEXTILE MIXTURE WITHIN PRESSURIZABLE SYSTEMSTECHNICAL FIELD

[0001] The present disclosure relates generally to textile recycling processes, such as processes for separating target polymers, including polyesters and nylons, from a feedstock of textile blend. Such processes may be used for selectively or successively recycling target polymers from textiles, including but not limited to post-consumer and post-industrial textiles.BACKGROUND

[0002] For textile recycling, resolution of mixed textile polymers into single-component streams is considered a critical process to enable successful conversion of waste into reusable materials. There are several methods by which this resolution can be effected, such as the selective destruction of one polymer into monomeric or oligomeric components while preserving a second polymer for isolation. The selective removal of single polymer components from mixed textiles non-destructively represents a preferred scenario in which the materials can be more easily converted into reusable feedstocks with minimal downstream processes. Polyester is a common component of commercial textile materials both in monomaterial and mixed textiles. The conversion of polyester polymer into liquid phase remains challenging in polymer science. It typically requires exotic, highly acidic solvents such as hexafluoroisopropanol (HFIP) or toxic solvent combinations such as tetrachloroethane / phenol or trichloroacetic acid / chloroform.Accordingly, the ability to, in the presence of other polymers, selectively convert polyester from a solid polymer to a suspended or dissolved liquid component for isolation and removal from the original solid textile polymer matrix represents a significant advancement in the field of textile recycling, enhancing the ability to resolve mixed textile materials into reusable materials.

[0003] Methods have been described in the prior art which use high boiling point solvents, such as sulfones (US5342854A), in which polyester is dissolved. These systems suffer from difficulty in separating the extraction medium from the textile polymer and depend upon anti-solvent precipitation systems, thereby limiting the use of the isolating component due to contamination with the extraction medium. Furthermore, efficient repeated use of the extraction process is diminished by an inability to effectively recycle and reuse the extractive medium. The ability to separate polymer and solvent via either temperature depression causing polymer precipitation, or by the thermal evaporation of the solvent component, eliminates the drawbacks shown by these systems.

[0004] Prior art also describes the sequential removal of dyes, additives, and polyester from textiles via the use of multiple extraction chemistries (US4003880A) in which the process switches between several, often highly toxic, solvent systems to effect the extraction across multiple components. Additionally, this process makes use of additives and mixtures within each individual process. The ability to use a single, one-component solvent system to remove disperse dyes, additives, and polyester polymers via the manipulation of temperature and / or pressure conditions permits polyester and textile purification to be more efficient and easier in comparison.

[0005] Nylon shares many of the liquid state processing challenges found in polyester. It also requires highly toxic and / or corrosive chemicals in order to dissolve it, such as formic acid or mineral acids. High boiling toxic solvents such as phenol are also known to dissolve nylon. Like polyester, these materials are challenging to implement at scale due to their safety hazards.

[0006] Corrosives are particularly challenging to use for mixed materials in which material incompatibility is problematic for controlled and stable separations. Like polyester, high boiling solvents present challenges in the design and implementation of repeatable processes that make use of them. Additionally, separation of the extraction medium from the polymer of interest is challenging. The use of anti-solvents to precipitate out the polymer from the high boiling solvent introduces complexity and inefficiency within the processes that make use of it.BRIEF SUMMARY

[0007] Provided herein are methods for recovering one or more target polymers from a polymer blend by selective solvation of target polymers, including polyester and nylon, and compositions comprising the recycled one or more target polymers.

[0008] One aspect of this description relates to a method of extracting a first polymer from a polymer blend comprising the first polymer and a second polymer different than the first polymer. The method comprises contacting the polymer blend with a first amount of a solvent under temperature and pressure conditions sufficient to dissolve the first polymer in the solvent while leaving the second polymer undissolved, and separating the solvent containing the dissolved first polymer from the undissolved second polymer.

[0009] In some embodiments, the polymer blend is a textile blend. In some embodiments, the first polymer is polyester or nylon. In some embodiments, the second polymer is cotton, nylon, polyester, or a combination thereof. In some embodiments, the first polymer is polyester, and the second polymer comprises cotton. In some embodiments, the first polymer is polyester, and the second polymer comprises nylon. In some embodiments, the first polymer ispolyester, and the second polymer comprises nylon and cotton. In some embodiments, the first polymer is nylon and the second polymer comprises cotton.

[0010] In some embodiments, the contacting is performed in a pressurizable vessel. In some embodiments, the temperature and pressure conditions comprise application of a pressure from 10 pounds per square inch (psi) to 100 psi. In some embodiments, the pressure is in a range of 10 psi to 90 psi. In some embodiments, the temperature and pressure conditions comprise a temperature of 80 °C to 250 °C. In some embodiments, the temperature conditions comprise a temperature of 100 °C to 190 °C. In some embodiments, the temperature conditions comprise a temperature of 160 °C to 180 °C.

[0011] In some embodiments, the solvent consists essentially of a ketone. In some embodiments, the solvent is a cyclic ketone. In some embodiments, the cyclic ketone has the structure (CH2)nCO, wherein n is 4, 5, 6 or 7. In some embodiments, the solvent is cyclohexanone. In some embodiments, the solvent has an atmospheric boiling point below 200°C. In some embodiments, the solvent has an atmospheric boiling point of 100°C to 190°C. In some embodiments, the solvent has an atmospheric boiling point in a range of 140-180°C. In some embodiments, the solvent is an organic solvent free of additives. In some embodiments, the contacting is performed for a duration of 30 minutes to 24 hours. In some embodiments, the contacting comprises heating the solvent to a temperature above an atmospheric boiling point of the solvent. In some embodiments, the temperature is at least 5 °C above the atmospheric boiling point of the solvent. In some embodiments, the temperature is at least 10 °C above the atmospheric boiling point of the solvent. In some embodiments, the temperature is at least 15 °C above the atmospheric boiling point of the solvent. In some embodiments, the temperature is at least 20 °C above the atmospheric boiling point of the solvent.

[0012] In some embodiments, the method further comprises recovering the first polymer from the solvent. In some embodiments, the recovering is achieved by precipitation. In some embodiments, the precipitation is achieved by cooling the solvent containing the dissolved first polymer. In some embodiments, the precipitation is achieved by evaporation of the solvent. In some embodiments, the method further comprises recovering the second polymer from the undissolved solid. In some embodiments, the polymer blend further comprises a component comprising a third polymer, a dye, a non-polymeric additive, or combinations thereof. In some embodiments, the component is not soluble in the solvent under the temperature and pressure conditions effective to dissolve the first polymer.

[0013] Alternatively or additionally, the method may further comprise, prior to the contacting step, applying temperature and pressure conditions effective to dissolve or suspend the component in the solvent, and separating the solvent containing the dissolved or suspendedcomponent from the polymer blend, wherein the temperature and pressure conditions effective to dissolve or suspend the component are different from the temperature and pressure conditions effective to dissolve the first polymer. In some embodiments, the temperature effective to dissolve or suspend the component is lower than the temperature effective to dissolve the first polymer. In some embodiments, the pressure effective to dissolve or suspend the component is lower than the pressure effective to dissolve the first polymer. In some embodiments, the temperature effective to dissolve or suspend the component is in a range of 80 °C to 110 °C. In some embodiments, the temperature effective to dissolve or suspend the component is about 100 °C. In some embodiments, a ratio of the solvent to the polymer blend is at least 3 : 1 by weight.

[0014] In some embodiments, the first polymer recovered retains at least 70% of the weight-average molecular weight (Mw) of the first polymer in the polymer blend. In some embodiments, the first polymer recovered retains at least 80% of the weight-average molecular weight (Mw) of the first polymer in the polymer blend. In some embodiments, the first polymer recovered retains at least 90% of the weight-average molecular weight (Mw) of the first polymer in the polymer blend. In some embodiments, the first polymer recovered has a poly dispersity index (PDI) of less than or equal to 3.0. In some embodiments, the first polymer recovered has a poly dispersity index (PDI) of less than or equal to 2.5. In some embodiments, the first polymer recovered has a polydispersity index (PDI) of less than or equal to 2.0. In some embodiments, the first polymer is polyester and the recovered polyester exhibits a crystallinity equal to or greater than that of the polyester in the polymer blend. In some embodiments, the recovered polyester exhibits a crystallinity of at least 30%, as measured by differential scanning calorimetry or X-ray diffraction. In some embodiments, the recovered polyester exhibits a crystallinity of at least 40%, as measured by differential scanning calorimetry or X-ray diffraction. In some embodiments, the recovered polyester exhibits a crystallinity of at least 50%, as measured by differential scanning calorimetry or X-ray diffraction.

[0015] In some embodiments, the contacting comprises heating the solvent to a temperature below an atmospheric boiling point of the solvent and applying pressure from an exogenous source to the pressurizable vessel to increase the pressure above atmospheric pressure. In some embodiments, the temperature is in a range of 160 °C to 180 °C. In some embodiments, the temperature is at least 160 °C. In some embodiments, the temperature is about 170 °C. In some embodiments, the temperature is in a range of 180 °C to 250 °C. In some embodiments, the temperature is at least 210°C. In some embodiments, the temperature is about 220 °C or about 225 °C.

[0016] In some embodiments, the component comprises elastane, and separating the component from the polymer blend prior to (a) comprises contacting the polymer blend with asecond amount of the solvent, applying temperature and pressure conditions effective to dissolve or suspend elastane in the solvent, and separating the solvent containing the dissolved or suspended elastane from the polymer blend. The temperature and pressure conditions effective to dissolve or suspend elastane are different from the temperature and pressure conditions effective to dissolve the first polymer. In some embodiments, the temperature effective to dissolve or suspend elastane is in a range of 110 °C to 155 °C. In some embodiments, the temperature effective to dissolve or suspend elastane is about 130 °C.

[0017] In some embodiments, the component comprises nylon dyes and the first polymer is nylon, separating the component from the polymer blend prior to (a) comprises contacting the polymer blend with a third amount of the solvent; separating the solvent containing the dissolved or suspended nylon dyes from the polymer blend, wherein the temperature and pressure conditions effective to dissolve or suspend the nylon dyes are lower than the temperature and pressure conditions effective to dissolve the nylon.

[0018] In some embodiments, the temperature effective to dissolve or suspend the nylon dyes is in a range of 175 °C to 185 °C. In some embodiments, the temperature effective to dissolve or suspend the nylon dyes is about 180 °C. In some embodiments, the method further comprises repeating the contacting and separating steps until at least 70% of the first polymer is removed from the polymer blend. In some embodiments, the steps are repeated until at least 80% of the first polymer is removed from the polymer blend. In some embodiments, the steps are repeated until at least 90% of the first polymer is removed from the polymer blend. In some embodiments, the separating is performed by filtration, ultrasonically aided filtration, or centrifugation. In some embodiments, the method further comprises mechanically squeezing the undissolved second polymer after separation. In some embodiments, the method further comprises drying the recovered first polymer via thermal processes, vacuum processes, or both. In some embodiments, the method further comprises drying the recovered second polymer via thermal processes, vacuum processes, or both. In some embodiments, the second polymer comprises cellulose.

[0019] Another aspect of this description relates to a method including using a single solvent to separate polyester from a polymer blend comprising at least one polymer different than the polyester to yield a composition comprising the polyester at a purity of at least 90%. In some embodiments, the at least one polymer comprises elastane, nylon, cotton, or cotton. In some embodiments, using the single solvent to separate the polyester from the polymer blend comprises applying heat and pressure for a period of time effective to dissolve or suspend the polyester in the single solvent. In some embodiments, the pressure is in a range of 10 psi to 90 psi. In some embodiments, the polymer blend is heated to a temperature ranging from 80 °C to250 °C. In some embodiments, the solvent consists essentially of a ketone. In some embodiments, the solvent is a cyclic ketone. In some embodiments, the cyclic ketone has the structure (CH2)nCO, wherein n is 4, 5, 6, or 7.

[0020] Still another aspect of this disclosure relates to a polyester composition produced according to a method comprising using a single solvent to separate polyester from a polymer blend comprising at least one polymer different than the polyester, wherein the polyester composition comprises polyester at a purity of at least 90%. In some embodiments, the at least one polymer comprises elastane, nylon, cotton, or cotton. In some embodiments, using the single solvent to separate the polyester from the polymer blend comprises applying heat and pressure for a period of time effective to dissolve or suspend the polyester in the solvent. In some embodiments, the pressure is in a range of 10 psi to 90 psi. In some embodiments, the polymer blend is heated to a temperature ranging from 80 °C to 250 °C. In some embodiments, the solvent consists essentially of a ketone. In some embodiments, the solvent is a cyclic ketone. In some embodiments, the cyclic ketone has the structure (CH2)nCO, wherein n is 4, 5, 6, or 7.BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

[0021] FIG. l is a flow diagram illustrating a method for recovering polyester from a polyester-containing textile feedstock, in accordance with some embodiments of the present disclosure.

[0022] FIG. 2 is a flow diagram illustrating a method for recovering nylon from a nylon-containing textile feedstock, in accordance with some embodiments of the present disclosure.

[0023] FIG. 3 is a flow diagram illustrating a method for recovering nylon dyes from a nylon dyes-containing textile feedstock, in accordance with some embodiments of the present disclosure.

[0024] FIG. 4 is a flow diagram illustrating a method for successively removing target polymers from a textile feedstock comprising polyester and nylon, in accordance with some embodiments of the present disclosure.

[0025] FIG. 5 illustrates solvation properties of cyclohexanone in a sealed vessel as the temperature increases.DETAILED DESCRIPTION

[0026] The present disclosure provides methods for selectively or successively recovering target polymers, including polyesters and nylons, from a textile blend by regulating the temperature and pressure of a solvent, for example, a single-component solvent. The methods disclosed herein enable the separation of polymers that do not dissolve below the boiling point ofthe single-component solvent in a pressure-free system, through the control of pressure within a pressure containment vessel at a temperature above the boiling point of the single-component solvent. As used herein, the term “single-component solvent” refers to a solvent free of additional chemical components purposefully added to enhance or otherwise alter the solvent's extractive properties, such as water, ammonia (NH3), alcohols or other molecular additives. The target polymer may be, for example, a type A polymer that can be dissolved or suspended in the single-component solvent at a temperature above its atmospheric boiling point under elevated pressure, or a type B polymer that remains solid in the single-component solvent under the same conditions where the type A polymer is dissolved or suspended. In some embodiments, the textile blend comprises cotton combined with polyester, nylon, or both.

[0027] The present disclosure solves several important problems in existing polymer processing. First, polyester and polyamide (e.g., nylon) are two widely used materials across multiple industries, products, and applications. However, options for liquid solution / suspension processing for these materials are highly limited due to the high cost, toxicity, and / or complexity of the solvents required to do so. The single-component solvent system with a favorable safety profile, free of additives, and activated using pressure and temperature described herein represents a significant advancement in the chemical processing of ubiquitous and useful polymer materials.

[0028] Second, the ability to selectively remove a polymeric material from a mixture of polymeric materials and / or non-polymeric components by controlling pressure and temperature is a highly desired process for the recovery and reuse of polymer-containing materials, specifically in the field of textile recycling. Conventional methods to perform this make use of destructive techniques that are deliberately used to lower a target polymer’s molecular weight such that it can be more easily dissolved. These techniques are challenging to tune for the specific degradation of a single polymer class, particularly within the synthetic polymers used for textiles such as elastane, polyester, and nylon. The ability to use temperature and pressure conditions to selectively target one polymer class among others represents a significant advancement in textile recycling and reprocessing. Further, this approach is an advantage over destructive techniques in which the removed material is functionally destroyed. By being able to extract polymers without deliberate, extensive degradation into oligomers and monomers, the recovery and re-use of polymeric materials derived from mixtures is greatly enabled. As a result, waste produced per material processed is reduced, efficiency is increased, and waste materials previously considered unrecyclable can now be considered recyclable.

[0029] Third, the temperature- and pressure-mediated solvation with a relatively low boiling point solvent enhances the recovery of the extracted polymeric materials post-extractionby forgoing the need for secondary anti-solvents to separate the extracted material from the solvent media. Additionally, it requires less energy in comparison to high boiling solvents and / or acids for solvent removal and recovery post-extraction.

[0030] Provided herein are methods of extracting a first polymer from a polymer blend comprising the first polymer and a second polymer (a “polymer blend”). The term “feedstock” or “feedstock material” may be used interchangeably with “polymer blend” to refer to the starting material comprising the first and second polymers. In some applications, the polymer blend can be a textile blend from any source. In some embodiments, the polymer blend may further comprise one or more components, including polymers, dyes, non-polymeric additives, and combinations thereof. In some embodiments, the polymer blend may comprise other materials such as material trim, wool, silk, and / or polyacrylics.

[0031] In some embodiments, feedstock polymer blends can include post-consumer textile waste comprising various apparel and garment types. Such materials may include shirts, blouses, and tops, as well as pants and trousers. In some applications, post-consumer textile waste can further comprise dresses and skirts, outerwear and jackets, activewear and sportswear, and underwear and intimates. In some embodiments, home textiles may serve as polymer blends. Such home textiles can include bedding materials comprising sheets and pillowcases, comforters and duvets, and blankets. In some applications, home textiles may further include curtains and drapes, upholstery fabrics, tablecloths and linens, and towels containing polyester. In some embodiments, footwear components can be utilized as feedstock. Such components may include shoe linings, synthetic fabric uppers, and laces. In some applications, pre-consumer textile waste may serve as a feedstock material. Such waste can include manufacturing cutting scraps, off-specification fabrics, production overruns, sample materials, and defective rolls or bolts. In some embodiments, industrial textiles may be used as feedstock. Such materials can include geotextiles, agricultural textiles, and filtration fabrics. In some embodiments, automotive textiles may be utilized, comprising seat covers, interior trim fabrics, carpet and floor mats, and headliners. In some embodiments, medical and hygiene textiles that are non-contaminated can serve as polymer blends.

[0032] In some applications, polymer blends can be categorized by fabric composition. Such categories may include 100% polyester fabrics and polyester-dominant blends. In some embodiments, polyester-dominant blends can comprise polyester-cotton blends, polyester-wool blends, polyester-rayon blends, polyester-nylon blends, and polyester-elastane / spandex blends. In some applications, multi-fiber complex blends may be utilized. In some embodiments, polymer blends can be characterized by fabric construction type. Such types may include woven fabrics comprising plain weave, twill weave, and satin weave. In some applications, knittedfabrics can be utilized, including weft knits and warp knits. In some embodiments, non-woven fabrics and braided structures may serve as feedstock. In some applications, polymer blends can be categorized by fabric finishing conditions. Such materials may include undyed or greige fabrics. In some embodiments, dyed fabrics can be utilized, including solid dyed, printed, and yarn-dyed materials. In some applications, finished fabrics with coatings may serve as feedstock, comprising materials with water-repellent treatments, flame-retardant treatments, anti-microbial treatments, and stain-resistant treatments. In some embodiments, laminated fabrics can be processed.

[0033] In some embodiments, polymer blends can be provided in various physical forms. Such forms may include whole garments or products, cut pieces or scraps, shredded or mechanically processed material, fiber fluff or lint, and pelletized textile waste. In some applications, polymer blends can be categorized by contamination level. Such categories may include clean or unworn materials, laundered post-consumer materials, and soiled materials requiring pre-cleaning. In some embodiments, materials with trims and accessories attached can be processed, where such attachments may include buttons and snaps, zippers, labels and tags, elastic bands, and decorative elements. In some embodiments, polymer blends can be categorized based on their source. Such sources may include residential collection programs, retail take-back programs, textile sorting facilities, landfill diversion streams, and export or import textile waste bales.

[0034] The polymer blends may further comprise one or more components comprising one or more polymers, dyes, non-polymeric additives, and combinations thereof. In some embodiments, polymeric contaminants may include other synthetic polymers such as polyamides (nylon), polyurethanes (elastane / spandex), polyacrylics, polypropylene, and polyethylene. In some applications, polymeric contaminants can include natural polymers. In some embodiments, natural polymers comprise cellulosic fibers including cotton, linen, viscose / rayon, lyocell, and modal. In some applications, natural polymers comprise protein-based fibers including wool and silk. In some embodiments, polymeric contaminants include polymer blends and copolymers such as polyester-cotton blends, polyester-elastane blends, and modified polyesters (copolyesters).

[0035] In some embodiments, colorants and dyes may be present, including disperse dyes, reactive dyes, acid dyes, vat dyes, pigments, and optical brighteners.

[0036] In some applications, non-polymeric additives are present. In some embodiments, non-polymeric additives comprise finishing agents including softeners, stiff eners / sizing agents, water repellents, soil release agents, flame retardants, anti-static agents, and antimicrobial agents. In some embodiments, non-polymeric additives comprise processing aids including lubricants,emulsifiers, and surfactants. In some applications, non-polymeric additives comprise performance modifiers including UV stabilizers, antioxidants, heat stabilizers, and plasticizers.

[0037] In some embodiments, physical contaminants may be present. In some applications, physical contaminants comprise non-textile components including buttons, zippers, rivets, snaps and fasteners, labels and tags, and thread where the thread is of a different composition. In some embodiments, physical contaminants comprise adhesives and bonding agents including seam adhesives, laminating adhesives, and interlining adhesives. In some applications, physical contaminants comprise coatings including polyurethane coatings, acrylic coatings, PVC coatings, and silicone coatings.

[0038] In some embodiments, residual substances from use may be present, including soil and particulates, body oils and proteins, detergent residues, fabric softener residues, and stains (organic and inorganic).

[0039] In some applications, degradation products may be present, including oligomers, hydrolysis products, photo-degradation products, thermal degradation products, and microplastics from fiber shedding.

[0040] In some embodiments, the first polymer may be polyester. In some embodiments, the first polymer may be nylon.

[0041] In some embodiments, the second polymer may be a synthetic polymer. For example, the second polymer may be nylon or polyester. When the second polymer is polyester, the first polymer may be polyester of a different type, for example, a different molecular weight, crystallinity, or copolymer composition. In some embodiments, the second polymer may be a natural polymer. For example, the second polymer may be a cellulose polymer such as cotton. In some embodiments, the second polymer may be a blended material. For example, the second polymer may be a combination of nylon and cotton.

[0042] In some embodiments, the first polymer is polyester and the second polymer is cotton. In some embodiments, the first polymer is polyester and the second polymer is nylon. In some embodiments, the first polymer is polyester, and the second polymer is nylon and cotton. In some embodiments, the first polymer is nylon and the second polymer is cotton.

[0043] The polymer blend may be contacted with a solvent under temperature and pressure conditions effective to dissolve the first polymer in the solvent while leaving the second polymer undissolved.

[0044] In some embodiments, the contacting is performed in a pressurizable vessel capable of maintaining a pressure above atmospheric pressure. In some embodiments, pressurizable vessels may have heating and mechanical stirring capabilities. In some applications, stainless steel pressure reactors with inert atmosphere provisions may be utilized.Pressurizable vessels may have, for example, solvent inlet and outlet ports. In some embodiments, pressurizable vessels may have internal baffles for enhanced mixing. In some applications, quick-opening closures for rapid loading and unloading may be used.

[0045] In some embodiments, pressurizable vessels with temperature control systems are provided, for example, jacketed pressure reactors with cooling and heating capabilities. In one embodiment, double-walled pressure vessels with safety containment features are utilized.

[0046] In some embodiments, high-pressure mixing vessels with recirculation loops are provided for polymer extraction applications. In some applications, continuous flow pressure vessels with inline mixing elements can be implemented.

[0047] In some embodiments, filtration chambers for separating dissolved polymer from undissolved components are provided. In some applications, vessels with internal mesh baskets or filters to contain solid polymer material may be employed. In one embodiment, pressurized centrifugal extractors combining pressure and centrifugal force can be utilized.

[0048] In some embodiments, multi-chamber pressurized extraction systems for sequential processing are provided. In some applications, supercritical fluid extraction vessels rated for elevated temperatures and pressures can be employed. In one embodiment, modular pressure vessel systems allowing variable chamber configurations may be utilized.

[0049] In some embodiments, the temperature and pressure conditions comprise application of a pressure from 10 pounds per square inch (psi) to 100 psi. Unless otherwise specified, all pressures recited herein are gauge pressures (psig). In some embodiments, the pressure is in a range of 15-100 psi, 20-90 psi, or 30-80 psi. In some embodiments, the pressure is in a range of 10-90 psi.

[0050] In some embodiments, the temperature and pressure conditions comprise a temperature of 80 °C to 250 °C. In some embodiments, the temperature conditions comprise a temperature of 100 °C to 190 °C. In some embodiments, the temperature conditions comprise a temperature of 140 °C to 180 °C. In some embodiments, the contacting comprises heating the solvent to a temperature above an atmospheric boiling point of the solvent. In some embodiments, the temperature is at least 5 °C above the atmospheric boiling point of the solvent. In some embodiments, the temperature is at least 10 °C above the atmospheric boiling point of the solvent. In some embodiments, the temperature is at least 15 °C above the atmospheric boiling point of the solvent. In some embodiments, the temperature is at least 20 °C above the atmospheric boiling point of the solvent. In some embodiments, the contacting comprises heating the solvent to a temperature below an atmospheric boiling point of the solvent, and an exogenous source of pressure is applied to the pressurizable vessel to increase a pressure of the pressurizable vessel above atmospheric pressure such that the first polymer is dissolved in thesolvent. In some embodiments, the first polymer is polyester, and the temperature sufficient to dissolve the first polymer but not the second polymer in the solvent is in a range of 160 °C to 180 °C. In some embodiments, the temperature is at least 160 °C. In some embodiments, the temperature is about 170°C. In some embodiments, the first polymer is nylon, and the temperature sufficient to dissolve the first polymer but not the second polymer in the solvent is in a range of 180 °C to 250 °C. In some embodiments, the temperature is at least 180 °C. In some embodiments, the temperature is about 190 °C or about 195 °C.

[0051] In some embodiments, the solvent is a ketone. In some embodiments, the solvent is a cyclic ketone. In some embodiments, the cyclic ketone has the structure (CH2)nCO, wherein n is 4, 5, 6, or 7. In some embodiments, the solvent comprises cyclopentanone, cyclohexanone, cycloheptanone, or cyclooctanone. In some embodiments, the solvent is cyclohexanone. In some embodiments, the solvent has an atmospheric boiling point below 200°C. In some embodiments, the solvent has an atmospheric boiling point of 100 °C to 190 °C. In some embodiments, the solvent has an atmospheric boiling point in a range of 140 °C to 180 °C. In some embodiments, the solvent is an organic solvent free of additives. In some embodiments, a ratio of the solvent to the polymer blend is at least 3 : 1 by weight.

[0052] The contacting is performed for a period of time effective to dissolve the first polymer in the solvent. In some embodiments, the contacting is performed for a duration of 30 minutes to 24 hours, for example, 30 minutes to 12 hours, 30 minutes to 6 hours, or 30 minutes to 3 hours. In some embodiments, the contacting is performed for a duration of at least 30 minutes, at least 1 hour, at least 2 hours, at least 3 hours, at least 4 hours, at least 5 hours, at least 6 hours, at least 8 hours, at least 10 hours, or at least 12 hours. In some embodiments, the contacting is performed for a duration of about 30 minutes, about 1 hour, about 2 hours, about 3 hours, about 4 hours, about 5 hours, about 6 hours, about 8 hours, about 10 hours, or about 12 hours. In some embodiments, the contacting is performed for a duration of up to 24 hours. In some embodiments, the contacting is performed for a duration of up to 12 hours. In some embodiments, the contacting is performed for a duration of up to 6 hours. In some embodiments, the contacting is performed for a duration of up to 3 hours. In some embodiments, the contacting is performed for a duration of up to 2 hours. In some embodiments, the contacting is performed for a duration of up to 1 hour. In some embodiments, the contacting is performed for a duration of up to about 30 minutes.

[0053] The methods may further comprise separating the solvent containing the dissolved first polymer from the undissolved second polymer. Any suitable separation method can be used to separate the liquid phase containing the dissolved first polymer from the solid phase containing the undissolved second polymer. In some embodiments, the separation is performedby filtration or centrifugation. In some embodiments, the method further comprises mechanically squeezing the undissolved second polymer after separation to recover additional solvent and / or dissolved first polymer.

[0054] In some embodiments, the method further comprises repeating the contacting and / or separating steps until a desired amount of the first polymer is removed from the polymer blend. For example, the steps may be repeated until at least 70% of the first polymer is removed from the polymer blend. In some embodiments, the steps are repeated until at least 80% of the first polymer is removed from the polymer blend. In some embodiments, the steps are repeated until at least 90% of the first polymer is removed from the polymer blend.

[0055] Generally, components of the blend which are undesired are not soluble in the solvent under the temperature and pressure conditions effective to dissolve the first polymer.

[0056] Such components may be removed by applying temperature and pressure conditions effective to dissolve or suspend the components in the solvent, and separating the solvent containing the dissolved or suspended components from the polymer blend. In some embodiments, the temperature and pressure conditions effective to dissolve or suspend the components are different from the temperature and pressure conditions effective to dissolve the first polymer. In some embodiments, the temperature effective to dissolve or suspend the components is lower than the temperature effective to dissolve the first polymer. In some embodiments, the pressure effective to dissolve or suspend the components is lower than the pressure effective to dissolve the first polymer. In some embodiments, the temperature effective to dissolve or suspend the components is in a range of 80 °C to 110 °C. In some embodiments, the temperature effective to dissolve or suspend the components is about 100 °C.

[0057] In some embodiments, the component comprises elastane. The method may further comprise, after contacting the polymer blend with the solvent, applying temperature and pressure conditions effective to dissolve or suspend elastane in the solvent, and separating the solvent containing the dissolved or suspended elastane from the polymer blend. The temperature and pressure conditions effective to dissolve or suspend elastane are different from the temperature and pressure conditions effective to dissolve the first polymer. In some embodiments, the temperature effective to dissolve or suspend elastane is in a range of 110 °C to 155 °C. In some embodiments, the temperature effective to dissolve or suspend elastane is about 130 °C.

[0058] In some embodiments, the component comprises nylon dyes, and the first polymer is nylon. The method may further comprise, after contacting the polymer blend with the solvent, applying temperature and pressure conditions effective to dissolve or suspend the nylon dyes in the solvent, and separating the solvent containing the dissolved or suspended nylon dyesfrom the polymer blend. The temperature and pressure conditions effective to dissolve or suspend the nylon dyes are lower than the temperature and pressure conditions effective to dissolve the nylon. In some embodiments, the temperature effective to dissolve or suspend the nylon dyes is in a range of 175-185 °C. In some embodiments, the temperature effective to dissolve or suspend the nylon dyes is about 180 °C. As used herein, the term “nylon dyes” refers to dyes suitable for nylon fibers including, but not limited to, acid dyes, metal-complex dyes, and reactive dyes. Examples of nylon dyes include Acid Red 88, Acid Blue 40, Acid Black 1, and pre-metallized azo dyes.

[0059] The method may further comprise recovering the first polymer from the solvent. In some embodiments, the recovering is achieved by precipitation. In some embodiments, the precipitation is achieved by cooling the solvent containing the dissolved first polymer. In some embodiments, the precipitation is achieved by evaporation of the solvent. In some embodiments, the precipitation is achieved by anti-solvent coagulation. The recovered first polymer may be dried. In some embodiments, the recovered first polymer is dried via thermal processes. In some embodiments, the recovered first polymer is dried via vacuum processes. In some embodiments, the recovered first polymer is dried via both thermal and vacuum processes.

[0060] The method may further comprise recovering the second polymer from the undissolved solid. The recovered second polymer may be dried. In some embodiments, the recovered second polymer is dried via thermal processes. In some embodiments, the recovered second polymer is dried via vacuum processes. In some embodiments, the recovered second polymer is dried via both thermal and vacuum processes.

[0061] In some embodiments, the first polymer recovered retains at least 70% of the weight-average molecular weight (Mw) of the first polymer in the polymer blend. In some embodiments, the first polymer recovered retains at least 80% of the weight-average molecular weight (Mw) of the first polymer in the polymer blend. In some embodiments, the first polymer recovered retains at least 90% of the weight-average molecular weight (Mw) of the first polymer in the polymer blend.

[0062] In some embodiments, the first polymer recovered has a poly dispersity index (PDI) of less than or equal to 3.0. In some embodiments, the first polymer recovered has a poly dispersity index (PDI) of less than or equal to 2.5. In some embodiments, the first polymer recovered has a poly dispersity index (PDI) of less than or equal to 2.0.

[0063] In some embodiments, the first polymer is polyester, and the recovered polyester exhibits a crystallinity equal to or greater than that of the polyester in the polymer blend. In some embodiments, the recovered polyester exhibits a crystallinity of at least 30%, as measured by differential scanning calorimetry or X-ray diffraction. In some embodiments, the recoveredpolyester exhibits a crystallinity of at least 40%, as measured by differential scanning calorimetry or X-ray diffraction. In some embodiments, the recovered polyester exhibits a crystallinity of at least 50%, as measured by differential scanning calorimetry or X-ray diffraction.

[0064] In some embodiments where the polymer blend contains multiple target polymers and components, the method may be performed successively using a single solvent system under varying temperature and pressure conditions. In some applications, components including dyes and non-polymeric additives can be removed at temperatures ranging from approximately 80 °C to approximately 110 °C, generally at about 100 °C. In some embodiments, elastane removal may be performed at temperatures ranging from approximately 110 °C to approximately 155 °C, for example, at about 130°C. In some applications, polyester extraction can be conducted at temperatures ranging from approximately 165 °C to approximately 180 °C, for example, at about 170 °C, with pressures ranging from approximately 15 psi to approximately 90 psi. In some embodiments, nylon dye removal may be performed at temperatures ranging from approximately 175 °C to approximately 185 °C, generally at about 180 °C, with pressures ranging from approximately 20 psi to approximately 95 psi. In some applications, nylon extraction can be conducted at temperatures ranging from approximately 180 °C to approximately 210 °C, generally at about 195 °C, with pressures ranging from approximately 25 psi to approximately 100 psi. In some embodiments, cotton may be recovered as the remaining solid comprising cellulose polymer.EXAMPLESEXAMPLE 1POLYESTER RECOVERY BY TEMPERATURE- AND PRESSURE-MEDIATED SOLVATION

[0065] FIG. 1 illustrates a method 100 for recovering polyester from a polyester-containing textile feedstock, in accordance with some embodiments of the present disclosure. It is understood that the method 100 is merely an example and is not intended to limit the present disclosure beyond what is explicitly recited in the claims. Additional operations can be provided before, during, and after the method 100, and some operations described can be replaced, eliminated, or moved around for additional embodiments of the method.

[0066] Referring to FIG. 1, at operation 102 of the method 100, a polyester-containing textile blend is charged to a vessel capable of maintaining pressures above atmospheric pressure. In some embodiments, the textile blend may contain cotton. In some embodiments, the textileblend may optionally contain other materials, such as material trim, wool, silk, and / or polyacrylics.

[0067] At operation 104 of the method 100, a solvent with an atmospheric boiling point below 200 °C is introduced into the vessel. The solvent may be added either before or after the textile blend is charged to the vessel. Therefore, in some embodiments, operation 104 may be performed before operation 102. In some embodiments, the solvent is a cyclic ketone. In some embodiments, the cyclic ketone is represented by the formula (CH2)nCO, with n being an integer of 4 or greater. In some embodiments, n is 4, 5, 6, or 7. In some embodiments, the solvent comprises cyclopentanone, cyclohexanone, cycloheptanone, or cyclooctanone. In some embodiments, the solvent is cyclohexanone. The ratio of the solvent to the textile blend (w / w) is at least 3:1.

[0068] In some embodiments, the vessel may be heated prior to or after charging the textile blend and solvent. The vessel may be either open or closed during application of an initial increasing temperature profile. In some embodiments, the vessel is initially heated to a temperature ranging from 80 °C to 165 °C.

[0069] At operation 106 of the method 100, the solvation of polyester is achieved by mediating the temperature and pressure. In some embodiments, after initial heating, the vessel is closed and further heated under a pressure above atmospheric pressure, for example, from 15 psi to 90 psi, to raise the internal temperature of the vessel above the atmospheric boiling point of the solvent. The pressure may be applied from an external source to facilitate dissolution of polyester. In the case where cyclohexanone is used, the internal temperature of the vessel after closing is raised to at least 160 °C for example 170 °C to allow for the solvation of polyester from the textile blend.

[0070] At operation 108 of the method 100, the liquid and solid phases in the vessel are separated. The technique to separate the liquid phase from the solid phase can be filtration, ultrasonically aided filtration, density based methods such as centrifugation, or other suitable separation methods.

[0071] Operations 104-108 may be repeated until all or a majority (e.g., greater than 70%) of the targeted component, polyester, is removed from the textile blend.

[0072] At operation 110, the polyester is recovered from the liquid phase. In some embodiments, the polyester can be recovered from the liquid phase by precipitation via cooling of the solution, evaporation of solvent, or anti-solvent coagulation. The polyester can then be dried via thermal and / or vacuum processes. The remaining solid phase can remain in the reaction vessel for re-processing in subsequent steps or it may be removed for reprocessing. In some embodiments, the solid may be recovered via filtration or other techniques and dried via thermalprocesses and / or vacuum processes. In some embodiments, the solid phase comprises cellulose polymer.EXAMPLE 2NYLON RECOVERY BY TEMPERATURE- AND PRESSURE-MEDIATED SOLVATION

[0073] FIG. 2 illustrates a method 200 for recovering nylon from a nylon-containing textile feedstock, in accordance with some embodiments of the present disclosure. It is understood that the method 200 is merely an example and is not intended to limit the present disclosure beyond what is explicitly recited in the claims. Additional operations can be provided before, during, and after the method 200, and some operations described can be replaced, eliminated, or moved around for additional embodiments of the method.

[0074] Referring to FIG. 2, at operation 202, a nylon-containing textile blend is charged to a vessel capable of maintaining pressures above atmospheric pressure. In some embodiments, the textile blend may contain cotton. In some embodiments, the textile blend may optionally contain other materials, such as material trim, wool, silk, and / or polyacrylics.

[0075] At operation 204 of the method 200, a solvent with an atmospheric boiling point below 200 °C is introduced into the vessel. The solvent may be added either before or after the textile blend is charged to the vessel. Therefore, in some embodiments, operation 204 may be performed before operation 202. In some embodiments, the solvent is a cyclic ketone. In some embodiments, the cyclic ketone is represented by the formula (CH2)nCO, with n being an integer of 4 or greater. In some embodiments, n is 4, 5, 6, or 7. In some embodiments, the solvent comprises cyclopentanone, cyclohexanone, cycloheptanone, or cyclooctanone. In some embodiments, the solvent is cyclohexanone. The ratio of the solvent to the textile blend (w / w) is at least 3:1.

[0076] In some embodiments, the vessel may be heated prior to or after charging the textile blend and solvent. The vessel may be either open or closed during application of heat. In some embodiments, the vessel is initially heated to a temperature ranging from 80 °C to 165 °C.

[0077] At operation 206 of the method 200, the solvation of nylon is achieved by adjusting the temperature and pressure. In some embodiments, after initial preparation, the vessel is closed and further heated under a pressure above atmospheric pressure, for example, from 15 psi to 90 psi, to raise the internal temperature of the vessel above the atmospheric boiling point of the solvent. The pressure may be applied from an external source to facilitate dissolution of nylon. In the case where cyclohexanone is used, the internal temperature of the vessel is raised to at least 180 °C, for example 190 °C, to allow for the solvation of nylon from the textile blend.

[0078] At operation 208 of the method 200, the liquid and solid phases of the vessel are separated. The technique to separate the liquid phase from the solid phase can be filtration, ultrasonically aided filtration, density based methods such as centrifugation, or other suitable separation methods.

[0079] Operations 204-208 may be repeated until all or a majority (e.g., greater than 70%) of the targeted component, nylon, is removed from the textile blend.

[0080] At operation 210, the nylon can be recovered from the liquid phase by precipitation via cooling of the solution, evaporation of solvent, or anti-solvent coagulation. The nylon can then be dried via thermal and / or vacuum processes. The remaining solid phase can remain in the reaction vessel for re-processing in subsequent steps, or it may be removed for reprocessing. In some embodiments, the solid may be recovered via filtration or other techniques and dried via thermal processes and / or vacuum processes. In some embodiments, the solid phase comprises cellulose polymer.EXAMPLE 3NYLON DYE REMOVAL BY TEMPERATURE- A D PRESSURE-MEDIATED SOLVATION

[0081] FIG. 3 illustrates a method 300 for removing nylon dyes from a dyed nylon-containing textile feedstock, in accordance with some embodiments of the present disclosure. It is understood that the method 300 is merely an example and is not intended to limit the present disclosure beyond what is explicitly recited in the claims. Additional operations can be provided before, during, and after the method 300, and some operations described can be replaced, eliminated, or moved around for additional embodiments of the method.

[0082] Referring to FIG. 3, at operation 302 of the method 300, a dyed nylon-containing textile blend is charged to a vessel capable of maintaining pressures above atmospheric pressure. In some embodiments, the textile blend may contain cotton. In some embodiments, the textile blend may optionally contain other materials, such as material trim, wool, silk, and / or polyacrylics.

[0083] At operation 304 of the method 300, a solvent with an atmospheric boiling point below 200 °C is introduced into the vessel. The solvent may be added before or after the textile blend is charged to the vessel. Therefore, in some embodiments, operation 304 may be performed before operation 302. In some embodiments, the solvent is a cyclic ketone. In some embodiments, the cyclic ketone is represented by the formula (CFkjnCO, with n being an integer of 4 or greater. In some embodiments, n is 4, 5, 6, or 7. In some embodiments, the point solvent comprises cyclopentanone, cyclohexanone, cycloheptanone, or cyclooctanone. In someembodiments, the solvent is cyclohexanone. The ratio of the solvent to the textile blend (w / w) is at least 3:1.

[0084] In some embodiments, the vessel may be heated prior to or after charging the textile blend and solvent. The vessel may be open or closed during application of heat. In some embodiments, the vessel is initially heated to a temperature ranging from 80 °C to 165 °C.

[0085] At operation 306 of the method 300, the solvation of the nylon dyes is achieved by adjusting the temperature and pressure. In some embodiments, after preparation of the mixture of the textile blend and the solvent, the vessel is closed and further heated under a pressure above atmospheric pressure, for example, from 15 psi to 90 psi, to raise the internal temperature of the vessel above the atmospheric boiling point of the solvent. In the case where the solvent is cyclohexanone, the internal temperature of the vessel is raised to at least 175 °C, for example 185 °C, to allow for the solvation of nylon dyes from the textile blend.

[0086] At operation 308 of the method 300, the liquid and solid phases of the vessel are separated. The technique to separate the liquid phase from the solid phase can be filtration, ultrasonically aided filtration, density based methods such as centrifugation, or other suitable separation methods.

[0087] Operations 304-308 may be repeated until all or a majority of the nylon dyes are removed from the textile blend.

[0088] At operation 310, the nylon dyes can be recovered from the liquid phase by precipitation via cooling of the solution, evaporation of solvent, or anti-solvent coagulation. After removing the nylon dyes from the dyed nylon, the remaining solid phase can be reprocessed by performing method 200 to recover nylon from the textile blend.EXAMPLE 4SUCCESSIVE REMOVAL OF TARGET POLYMERS FROM TEXTILE BLEND CONTAINING NYLON,ELASTANE, POLYESTER, AND COTTON

[0089] FIG. 4 illustrates a method 400 for successively removing target polymers from a textile feedstock comprising polyester and nylon, in accordance with some embodiments of the present disclosure. It is understood that the method 400 is merely an example and is not intended to limit the present disclosure beyond what is explicitly recited in the claims. Additional operations can be provided before, during, and after the method 400, and some operations described can be replaced, eliminated, or moved around for additional embodiments of the method.

[0090] Referring to FIG. 4, at operation 402 of the method 400, a textile blend containing nylon, polyester, cotton, and elastane, as well as associated dyes and additives, is charged to avessel capable of maintaining pressures above atmospheric pressure. In some embodiments, the textile blend may optionally contain other materials, such as material trim, wool, silk, and / or polyacrylics.

[0091] At operation 404 of the method 400, a solvent with an atmospheric boiling point below 200 °C is introduced into the vessel. The solvent may be added either before or after the textile blend is charged to the same vessel. Therefore, in some embodiments, operation 404 may be performed before operation 402. In some embodiments, the solvent is a cyclic ketone. In some embodiments, the cyclic ketone is represented by the formula (CH2)nCO, with n being an integer of 4 or greater. In some embodiments, n is 4, 5, 6, or 7. In some embodiments, the solvent comprises cyclopentanone, cyclohexanone, cycloheptanone, or cyclooctanone. In some embodiments, the solvent is cyclohexanone. The ratio of the solvent to the textile blend (w / w) is at least 3:1.

[0092] In some embodiments, the vessel may be heated prior to or after charging the textile blend and solvent. The vessel may be either open or closed during application of heat. In some embodiments, the vessel is initially heated to a temperature ranging from 80 °C to 165 °C.

[0093] At operation 406 of the method 400, non-polymeric components including dyes and organic additives are removed. To remove the non-polymeric components, the vessel is first maintained at a temperature sufficient to remove the dyes and organic additives, typically around 80-110 °C, for example 100 °C. The liquid and solid phases are separated using standard techniques. The remaining solid may be mechanically squeezed. The extraction at these conditions may be repeated until all or a majority (e.g., greater than 70%) of the non-polymeric components are removed from the solid.

[0094] At operation 408 of the method 400, upon satisfactory completion of operation 406, the solvation of elastane is achieved. After removing the non-polymeric components, operation 404 is performed to introduce additional solvent into the vessel. Next, the temperature of the vessel containing the remaining solid component is raised under the atmospheric pressure to 110 °C-155 °C, for example 130 °C, upon which elastane becomes dissolved in the solvent. The liquid and solid phases are separated using standard techniques. The remaining solid may be mechanically squeezed. The extraction at these conditions may be repeated until all or a majority (e.g., greater than 70%) of the elastane component is removed from the solid.

[0095] At operation 410 of the method 400, the solvation of polyester is achieved by adjusting the temperature and pressure. After removing the elastane component, operation 404 is performed to introduce additional solvent into the vessel. The vessel is then sealed and the temperature of the vessel containing the remaining solid component is raised to 165 °C- 180 °C under a pressure above the atmospheric pressure, for example, from 15 psi to 90 psi. Pressuremay be applied from an external source to facilitate dissolution of polyester. After a period of time sufficient to achieve dissolution, the solid and liquid phases are separated from one another using standard techniques, typically using pump aided filtration. The extraction at these conditions may be repeated until all or a majority (e.g., greater than 70%) of the polyester component is removed from the solid.

[0096] At operation 412 of the method 400, the solvation of nylon dyes is achieved by adjusting the temperature and pressure. After removing the polyester component, operation 404 is performed to introduce additional solvent into the vessel. The vessel’s internal temperature is then raised under a pressure above the atmospheric pressure, for example, from 20 psi to 95 psi, to 175-185 °C, for example 180 °C, upon which nylon dyes are dissolved in the solvent. Pressure may be applied from an external source to facilitate dissolution of nylon dyes. After a period of time sufficient to achieve dissolution, the solid and liquid phases are separated from one another using standard techniques, typically using pump aided filtration. The extraction at these conditions may be repeated until all or a majority of the nylon dyes are removed from the solid.

[0097] At operation 414 of the method 400, the solvation of nylon is achieved by adjusting the temperature and pressure. After removing the nylon dyes, operation 404 is performed to introduce additional solvent into the vessel. The vessel’s internal temperature is then raised under a pressure above the atmospheric pressure, for example, from 25 psi to 100 psi, to 180-210 °C, for example 195 °C, upon which nylon is dissolved in the solvent. Pressure may be applied from an external source to facilitate dissolution of nylon. After a period of time sufficient to achieve dissolution, the solid and liquid phases are separated from one another using standard techniques, typically using pump aided filtration. The extraction at these conditions may be repeated until all or a majority of the nylon component is removed from the solid. The remaining solid cotton can remain in the reaction vessel for re-processing in subsequent steps, or it may be removed for reprocessing. In some embodiments, the solid may be recovered via filtration or other techniques and dried via thermal processes and / or vacuum processes. In some embodiments, this solid phase comprises cellulose polymer.

[0098] The solvation properties of cyclohexanone in a sealed vessel as the temperature increases are shown in FIG. 5.

[0099] The foregoing description has broad application. The discussion of any embodiment is meant only to be explanatory and is not intended to suggest that the scope of the disclosure, including the claims, is limited to these examples. In other words, while illustrative embodiments of the disclosure have been described in detail herein, the inventive concepts may be otherwise variously embodied and employed, and the appended claims are intended to be construed to include such variations, except as limited by the prior art.

[0100] All of the above U.S. patents, U.S. patent applications, foreign patents, foreign patent applications and non-patent publications referred to in this specification, are incorporated herein by reference in their entirety, including U.S. Provisional Patent Application No.63 / 761,753 filed February 21, 2025, unless otherwise stated.

[0101] The foregoing discussion has been presented for purposes of illustration and description and is not intended to limit the disclosure to the form or forms disclosed herein. For example, various features of the disclosure are grouped together in one or more aspects, embodiments, or configurations for the purpose of streamlining the disclosure. However, various features of the certain aspects, embodiments, or configurations of the disclosure may be combined in alternate aspects, embodiments, or configurations. Moreover, the following claims are hereby incorporated into this Detailed Description by this reference, with each claim standing on its own as a separate embodiment of the present disclosure.1

Claims

CLAIMSWHAT IS CLAIMED IS:

1. A method of extracting a first polymer from a polymer blend comprising the first polymer and a second polymer different than the first polymer, the method comprising:(a) contacting the polymer blend with a first amount of a solvent under temperature and pressure conditions sufficient to dissolve the first polymer in the solvent while leaving the second polymer undissolved; and(b) separating the solvent containing the dissolved first polymer from the undissolved second polymer.

2. The method of claim 1, wherein the polymer blend is a textile blend.

3. The method of claim 1 or 2, wherein the first polymer is polyester or nylon.

4. The method of claim 3, wherein the second polymer is cotton, nylon, polyester, or a combination thereof.

5. The method of claim 3 or 4, wherein the first polymer is polyester and the second polymer comprises cotton.

6. The method of claim 3 or 4, wherein the first polymer is polyester and the second polymer comprises nylon.

7. The method of claim 3 or 4, wherein the first polymer is polyester and the second polymer comprises nylon and cotton.

8. The method of claim 3 or 4, wherein the first polymer is nylon and the second polymer comprises cotton.

9. The method of any one of claims 1-8, wherein the contacting in (a) is performed in a pressurizable vessel.

10. The method of claim 9, wherein the temperature and pressure conditions of (a) comprise application of a pressure from 10 pounds per square inch (psi) to 100 psi.

11. The method of claim 10, wherein the pressure is in a range of 10 psi to 90 psi.12 The method of any one of claims 1-11, wherein the temperature and pressure conditions of step (a) comprise a temperature of 80 °C to 250 °C.

13. The method of claim 12, wherein the temperature conditions of (a) comprise a temperature of 100 °C to 190 °C.

14. The method of claim 12, wherein the temperature conditions of (a) comprise a temperature of 160 °C tol80°C.

15. The method of any one of claims 1-14, wherein the solvent consists essentially of a ketone.

16. The method of claim 15, wherein the solvent is a cyclic ketone.

17. The method of claim 16, wherein the cyclic ketone has the structure (CH2)nCO, wherein n is 4, 5, 6 or 7.

18. The method of claim 17, wherein the solvent is cyclohexanone.

19. The method of any one of claims 1-18, wherein the solvent has an atmospheric boiling point below 200 °C.

20. The method of claim 19, wherein the solvent has an atmospheric boiling point of 100 °C to 190 °C.

21. The method of claim 19, wherein the solvent has an atmospheric boiling point in a range of 140 °C to 180 °C.

22. The method of any one of claims 1-21, wherein the solvent is an organic solvent free of additives.

23. The method of any one of claims 1-22, wherein (a) is performed for a duration of 30 minutes to 24 hours.

24. The method of any one of claims 1-23, wherein (a) comprises heating the solvent to a temperature above an atmospheric boiling point of the solvent.

25. The method of claim 24, wherein the temperature is at least 5 °C above the atmospheric boiling point of the solvent.

26. The method of claim 24, wherein the temperature is at least 10 °C above the atmospheric boiling point of the solvent.

27. The method of claim 24, wherein the temperature is at least 15 °C above the atmospheric boiling point of the solvent.

28. The method of claim 24, wherein the temperature is at least 20 °C above the atmospheric boiling point of the solvent.

29. The method of any one of claims 1-28, further comprising recovering the first polymer from the solvent.

30. The method of claim 29, wherein the recovering is achieved by precipitation.

31. The method of claim 30, wherein the precipitation is achieved by cooling the solvent containing the dissolved first polymer.

32. The method of claim 30, wherein the precipitation is achieved by evaporation of the solvent.

33. The method of any one of claims 1-32, further comprising recovering the second polymer from the undissolved solid.

34. The method of any one of claims 1-33, wherein the polymer blend further comprises a component comprising a third polymer, a dye, a non-polymeric additive, or combinations thereof.

35. The method of claim 34, wherein the component is not soluble in the solvent under the temperature and pressure conditions effective to dissolve the first polymer.

36. The method of claim 34 or 35, further comprising, prior to (a):applying temperature and pressure conditions effective to dissolve or suspend the component in the solvent; andseparating the solvent containing the dissolved or suspended component from the polymer blend;wherein the temperature and pressure conditions effective to dissolve or suspend the component are different from the temperature and pressure conditions effective to dissolve the first polymer.

37. The method of claim 36, wherein the temperature effective to dissolve or suspend the component is lower than the temperature effective to dissolve the first polymer.

38. The method of claim 36 or 37, wherein the pressure effective to dissolve or suspend the component is lower than the pressure effective to dissolve the first polymer.

39. The method of any one of claims 36-38, wherein the temperature effective to dissolve or suspend the component is in a range of 80 °C tol 10 °C.

40. The method of claim 39, wherein the temperature effective to dissolve or suspend the component is about 100 °C.

41. The method of any one of claims 1-40, wherein a ratio of the solvent to the polymer blend is at least 3 : 1 by weight.

42. The method of any one of claims 1-41, wherein the first polymer recovered in (b) retains at least 70% of the weight-average molecular weight (Mw) of the first polymer in the polymer blend.

43. The method of claim 42, wherein the first polymer recovered in (b) retains at least 80% of the weight-average molecular weight (Mw) of the first polymer in the polymer blend.

44. The method of claim 42, wherein the first polymer recovered in (b) retains at least 90% of the weight-average molecular weight (Mw) of the first polymer in the polymer blend.

45. The method of any one of claims 1-44, wherein the first polymer recovered in (b) has a poly dispersity index (PDI) of less than or equal to 3.0.

46. The method of claim 45, wherein the first polymer recovered in (b) has a poly dispersity index (PDI) of less than or equal to 2.5.

47. The method of claim 45, wherein the first polymer recovered in (b) has a poly dispersity index (PDI) of less than or equal to 2.0.

48. The method of any one of claims 1-47, wherein the first polymer is polyester and the recovered polyester exhibits a crystallinity equal to or greater than that of the polyester in the polymer blend.

49. The method of claim 48, wherein the recovered polyester exhibits a crystallinity of at least 30%, as measured by differential scanning calorimetry or X-ray diffraction.

50. The method of claim 48, wherein the recovered polyester exhibits a crystallinity of at least 40%, as measured by differential scanning calorimetry or X-ray diffraction.

51. The method of claim 48, wherein the recovered polyester exhibits a crystallinity of at least 50%, as measured by differential scanning calorimetry or X-ray diffraction.

52. The method of any one of claims 1-51, wherein (a) comprises heating the solvent to a temperature below an atmospheric boiling point of the solvent and applying pressure from an exogenous source to the pressurizable vessel to increase the pressure above atmospheric pressure.

53. The method of any one of claims 5-7 or 9-52, wherein the temperature in (a) is in a range of 160 °C to 180 °C.

54. The method of claim 53, wherein the temperature in (a) is at least 160 °C.

55. The method of claim 53 or 54, wherein the temperature in (a) is about 170 °C.

56. The method of any one of claims 8-52, wherein the temperature in (a) is in a range of 180 °C to 250 °C.

57. The method of claim 56, wherein the temperature in (a) is at least 210 °C.

58. The method of claim 56 or 57, wherein the temperature in (a) is about 220 °C or about 225 °C.

59. The method of any one of claims 34-40, wherein the component comprises elastane, wherein separating the component from the polymer blend prior to (a) comprises:contacting the polymer blend with a second amount of the solvent;applying temperature and pressure conditions effective to dissolve or suspend elastane in the solvent; andseparating the solvent containing the dissolved or suspended elastane from the polymer blend;wherein the temperature and pressure conditions effective to dissolve or suspend elastane are different from the temperature and pressure conditions effective to dissolve the first polymer.

60. The method of claim 59, wherein the temperature effective to dissolve or suspend elastane is in a range of 110 °C to 155 °C.

61. The method of claim 60, wherein the temperature effective to dissolve or suspend elastane is about 130°C.

62. The method of any one of claims 34-40 or 59-61, wherein the component comprises nylon dyes and the first polymer is nylon, wherein separating the component from the polymer blend prior to (a) comprises:contacting the polymer blend with a third amount of the solvent;applying temperature and pressure conditions effective to dissolve or suspend the nylon dyes in the solvent; andseparating the solvent containing the dissolved or suspended nylon dyes from the polymer blend;wherein the temperature and pressure conditions effective to dissolve or suspend the nylon dyes are lower than the temperature and pressure conditions effective to dissolve the nylon.

63. The method of claim 62, wherein the temperature effective to dissolve or suspend the nylon dyes is in a range of 175 °C to 185 °C.

64. The method of claim 63, wherein the temperature effective to dissolve or suspend the nylon dyes is about 180 °C.

65. The method of any one of claims 1-64, further comprising repeating (a) and (b) until at least 70% of the first polymer is removed from the polymer blend.

66. The method of claim 65, wherein steps (a) and (b) are repeated until at least 80% of the first polymer is removed from the polymer blend.

67. The method of claim 65, wherein steps (a) and (b) are repeated until at least 90% of the first polymer is removed from the polymer blend.

68. The method of any one of claims 1-67, wherein the separating in (b) is performed by filtration, ultrasonically aided filtration, or centrifugation.

69. The method of any one of claims 1-68, further comprising mechanically squeezing the undissolved second polymer after separation.

70. The method of any one of claims 1-69, further comprising drying the recovered first polymer via thermal processes, vacuum processes, or both.

71. The method of any one of claims 1-70, further comprising drying the recovered second polymer via thermal processes, vacuum processes, or both.

72. The method of any one of claims 1-71, wherein the second polymer comprises cellulose.

73. A method comprising using a single solvent to separate polyester from a polymer blend comprising at least one polymer different than the polyester to yield a composition comprising the polyester at a purity of at least 90%.

74. The method of claim 73, wherein the at least one polymer comprises elastane, nylon, cotton, or cotton.

75. The method of claim 73 or 74, wherein using the single solvent to separate the polyester from the polymer blend comprises applying heat and pressure for a period of time effective to dissolve or suspend the polyester in the solvent.

76. The method of any one of claims 73-75, wherein the pressure is in a range of 10 psi to 90 psi.

77. The method of any one of claims 73-76, wherein the polymer blend is heated to a temperature ranging from 80 °C to 250 °C.

78. The method of any one of claims 73-77, wherein the solvent consists essentially of a ketone.

79. The method of claim 78, wherein the solvent is a cyclic ketone.

80. The method of claim 79, wherein the cyclic ketone has the structure (CH2)nCO, wherein n is 4, 5, 6, or 7.

81. A polyester composition formed according to a method comprising using a single solvent to separate polyester from a polymer blend comprising at least one polymer different than said polyester, wherein said polyester composition comprises polyester at a purity of at least 90%.

82. The composition of claim 81, wherein the at least one polymer comprises elastane, nylon, cotton, or cotton.

83. The composition of claim 81 or 82, wherein using the single solvent to separate the polyester from the polymer blend comprises applying heat and pressure for a period of time effective to dissolve or suspend the polyester in the solvent.

84. The composition of any one of claims 81-83, wherein the pressure is in a range of 10 psi to 90 psi.

85. The composition of any one of claims 81-84, wherein the polymer blend is heated to a temperature ranging from 80 °C to 250 °C.

86. The composition of any one of claims 81-85, wherein the solvent consists essentially of a ketone.

87. The composition of claim 86, wherein the solvent is a cyclic ketone.

88. The composition of claim 87, wherein the cyclic ketone has the structure(CH2)nC0, wherein n is 4, 5, 6, or 7.

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