Bio-based compostable elastomeric materials, methods of manufacture and articles and uses thereof

Abstract

Compositions, systems, and methods are provided for making bio-based biodegradable elastomeric materials in the form of fibers, foams, and molded articles, as well as various articles made using the same. The elastomeric material consists essentially of a diacid and a diol, and a supporting polymer structure, with or without a cross-linking agent.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims the benefit of priority to U.S. Provisional Application No. 63 / 434,257, filed December 21, 2022, which is incorporated herein by reference in its entirety. Technical Field

[0003] The present disclosure relates to bio-based compostable elastic materials, methods for making the same, and uses thereof.The elastic materials are polymers made from diacids and diols, with or without a cross-linking agent, and a supporting polymer structure. Background Art

[0004] Polyurethanes (including the elastic fibers better known commercially as spandex) are a class of polymers with excellent tensile and elongation properties that range from hard resins to highly resilient sponges. They exist in a variety of forms, from fibers to foams, and are used in a wide range of applications, from mattresses to stretch pants and automotive interiors. However, elastic fibers and polyurethanes are often difficult to recycle at standard roadside facilities, and their components are neither biodegradable nor compostable. In addition, isocyanates (one of the crosslinking agent molecules commonly used in elastic fibers and polyurethanes) are known toxins.

[0005] Previously, compostable elastomers, such as polybutylene adipate terephthalate (PBAT), have been produced. However, these polymers have high stiffness and low elongation and are unsuitable for soft elastomer applications such as textiles and packaging. Furthermore, the source molecules are petrochemical-based.

[0006] Citric acid-based elastomers are also known. However, these elastomers suffer from several drawbacks, including their brittleness, poor mechanical properties, long cure times, and, most importantly, their inability to be processed into fibers, resins, or foams.

[0007] There is a need for compostable elastomers made from non-toxic bio-based materials without compromising their physical properties or performance characteristics. Summary of the Invention

[0008] The present disclosure generally relates to biodegradable compostable elastomeric materials, which are made from bio-based materials and have the desired properties of tensile properties and elongation properties. In some embodiments, the elastomeric materials produced according to the methods provided herein can overcome the limitations of the prior art. An object of the present disclosure is to provide an elastomeric material that maintains the performance and process attributes of polyurethane and elastic fibers while changing the chemical composition to 100% bio-based compostable materials. The compositions and process parameters described herein have been selected to maximize tensile properties (including elongation) while also producing a unique blend of thermoplastic biopolymers and cross-linked polymers that allows melt processability and thermoformability.

[0009] In a first broad aspect of the present disclosure, elastomeric properties are achieved by combining bio-alcohol and bio-acid using a bio-based cross-linker such as glycerol or citric acid.

[0010] In a second broad aspect of the present disclosure, elastomeric properties are achieved using linear polymers composed of bio-based compostable diols that are reacted with diacids to form biopolyesters. Copolymers composed of hard segments such as terephthalic acid and soft segments such as poly(ethylene glycol) also have high elongation and complete elastic recovery after stretching.

[0011] In a third broad aspect of the present disclosure, elastomeric properties are achieved using a linear polymer composed of a bio-based compostable diol that is reacted with a diacid in the presence of a crosslinker comprising both a thermal initiator and a photoinitiator to form a biopolyester. In some such embodiments, the crosslinker comprises two reactive sites: one that is thermally activated before extrusion or inside the extruder, and one that is UV-activated, for example, after extrusion, such as by exposure to UV light. Non-limiting examples of such crosslinkers include itaconic acid, maleic acid, maleic anhydride, and combinations thereof. Without wishing to be bound by theory, the use of such a crosslinker allows extrusion (fibers and foams can be extruded because the crosslinker is not thermosetting like other crosslinkers, such as citric acid), wherein the crosslinking is activated by UV light outside the extruder (i.e., after extrusion). Such fibers and foams can have advantageous properties such as, for example, but not limited to: high elongation, e.g., at least 50%, at least 200%, up to 600% elongation; up to 1000%, or about 200% elongation; high tenacity, e.g., tenacity of at least 0.6 g / denier to 5 g / denier; denier size of about 25 to about 40, about 25, at least 25, about 40, or at least 40; full elastic recovery after stretching; and combinations thereof.

[0012] In some embodiments, a bio-based compostable stretchable polymer is provided, which is made by reacting one or more diols with a diacid or triacid and then curing at high temperature. In some embodiments, the diol is 1,4-butanediol, pentanediol, hexanediol, octanediol, decanediol or dodecanediol. In some embodiments, the diacid is sebacic acid, succinic acid, adipic acid, lactic acid or boric acid. In some embodiments, the stretchable polymer further comprises a cross-linking agent, such as, but not limited to, citric acid or boric acid. In some embodiments, the stretchable polymer further comprises a cross-linking agent, such as, but not limited to, itaconic acid, maleic acid, maleic anhydride or a combination thereof. In some embodiments, the stretchable polymer further comprises a reinforcing agent added to improve stiffness and / or fracture resistance, such as, but not limited to, microcrystalline cellulose, nanocrystalline cellulose, titanium dioxide, kaolin, silica, nanoclay, carbon black or a combination thereof. In some embodiments, the stretchable polymer is blended with a carrier polymer, for example, to obtain a desired viscosity and / or consistency, for example, suitable for processing into fibers or foams. Non-limiting examples of carrier polymers include cellulose, cellulose derivatives, poly(lactic acid), polycaprolactam, starch, and other biopolymers.

[0013] In some embodiments, the bio-based compostable stretchable polymer exhibits an elongation of at least 50%, at least 200%, up to 600%; or up to 1000%.

[0014] In some embodiments, the biobased compostable stretchable polymer has a tenacity of at least 5 g / denier.

[0015] In some embodiments, the bio-based compostable stretchable polymer fibers have a denier size of about 25. In some embodiments, the bio-based compostable stretchable polymer fibers have a denier size of about 40. In some embodiments, the bio-based compostable stretchable polymer fibers have a denier size of about 25 to about 40.

[0016] In some embodiments, the bio-based compostable stretchable polymer can fully recover its original length after the stress is removed.

[0017] In some embodiments, the bio-based compostable stretchable polymer can undergo at least 100 relaxation and extension cycles without any fatigue.

[0018] In some embodiments, the bio-based compostable stretchable polymer is suitable for processing into fibers, such as via melt spinning, solution spinning, electrospinning, or melt blowing. The fiber size can be, for example, 50 denier to 150 denier. The fiber can typically be woven or knitted with cotton, polyester, or other fibers to form a stretch fabric.

[0019] In some embodiments, a stretch fabric is provided that comprises the bio-based compostable stretchable polymer described herein. In some such embodiments, the stretch fabric remains intact after 25 wash, rinse, and dry cycles without loss of quality or physical properties.

[0020] In some embodiments, a knitted or woven fabric is provided that comprises the bio-based compostable stretchable polymer described herein. In some such embodiments, the knitted or woven fabric further comprises cotton, polyester, nylon, or a combination thereof.

[0021] In some embodiments, the bio-based compostable stretchable polymer is suitable for molding into articles, such as via injection molding or 3D printing. For example, the bio-based compostable stretchable polymer of the present disclosure can be made into a mesh structure or foam by introducing a foaming agent. In some embodiments, the bio-based compostable stretchable polymer is thermoformable at elevated temperatures.

[0022] In some embodiments, the biobased compostable stretchable polymer is made partially or entirely from plant-derived molecules.

[0023] In some embodiments, the bio-based compostable stretchable polymer is fully biodegradable at the end of its life.

[0024] In some embodiments, the bio-based compostable stretchable polymer is fully compostable at the end of its life.

[0025] In some embodiments, the bio-based compostable stretchable polymer is fully recyclable at the end of its life. In some such embodiments, the polymer can be broken down into its constituent monomers by an increase in pH, which can then be recovered and re-spun into new fibers.

[0026] In some embodiments, the bio-based compostable stretchable polymer can be separated from the blend via an increase in pH. The increase in pH can, for example, cause the polymer to hydrolyze into its monomers, which can then further react to form new polymers, thereby promoting recycling. In some such embodiments, the pH is increased to a pH of about 11 to about 13, or to a pH of 11, a pH of 12, or a pH of 13.

[0027] In some embodiments, the bio-based compostable stretchable polymers are suitable for use in replacing fibers in, for example, clothing, underwear, automotive interiors, medical textiles, and / or wound dressings.

[0028] In some embodiments, the bio-based compostable stretchable polymers are suitable for replacing polyurethane foams in applications such as insulation, packaging, and apparel.

[0029] In some embodiments, the bio-based compostable stretchable polymer is suitable for use in place of poly(dimethylsilicone) for molded elastomeric articles, such as for cell phone cases, sealants, or household items such as, but not limited to, mattresses or furniture.

[0030] In some embodiments, the bio-based compostable stretchable polymer comprises polyglyceryl sebacate (PGS) or polyoctyl citrate (POC):

[0031] Polyglyceryl Sebacate (PGS)

[0032]

[0033] In some embodiments, the bio-based compostable stretchable polymer comprises a carrier polymer that is cellulose acetate (CA):

[0034]

[0035] In some embodiments, foams are provided that include the bio-based compostable stretchable polymers described herein. In some embodiments, the foams of the present disclosure further include a surfactant that can increase the density and / or uniformity of the foam, such as, but not limited to, castor oil.

[0036] In some embodiments, molded articles comprising the biobased compostable stretchable polymers described herein are provided.

[0037] In some embodiments, fibers comprising the biobased compostable stretchable polymers described herein are provided.

[0038] In some embodiments, articles comprising the biobased compostable stretchable polymers described herein are provided. Non-limiting examples of such articles include clothing, underwear, woven fabrics, knitted fabrics, stretch fabrics, automotive interiors, medical textiles, wound dressings, insulation materials, packaging materials, mobile phone cases, sealants, household goods, mattresses, furniture, and the like.

[0039] In one embodiment, a biodegradable and compostable bio-based elastomeric fiber is provided, having an elongation of at least 50%, up to 600%, or a maximum elongation of up to 1000%; after the stress is removed, its original length can be fully recovered; and it can undergo at least 100 relaxation and extension cycles without any fatigue. In some such embodiments, the tenacity of the elastomeric fiber is at least 5g / denier. In some such embodiments, the denier size of the elastomeric fiber is at least about 40. In some such embodiments, the elastomeric fiber comprises a diol that reacts with a diacid or a triacid and cures at high temperature. In some such embodiments, the elastomeric fiber comprises polyglyceryl sebacate (PGS) or polyoctanediol citrate (POC), and optionally further comprises a carrier polymer that is cellulose acetate (CA). In other embodiments, the elastomeric fiber comprises a diol that reacts with a diacid in the presence of a crosslinking agent, the crosslinking agent comprising both a thermal initiator and a photoinitiator, and the elastomeric fiber is formed by extrusion and then UV curing. In some such embodiments, the crosslinking agent is itaconic acid, maleic acid, or a combination thereof. In some such embodiments, a plurality of diols and a plurality of diacids are esterified together (i.e., in the first step). Such esterification can prevent crystallization and / or maximize the elongation of the fiber. Non-limiting examples of diols for such embodiments include propylene glycol and / or 1,4-butanediol. Non-limiting examples of diacids for such embodiments include sebacic acid and / or succinic acid.

[0040] In another aspect, a method for making the bio-based compostable stretchable polymer of the present specification is provided. In one embodiment, octanediol, sebacic acid, and citric acid are combined in equal moles and melted at 80°C to a honey-like consistency. Thereafter, cellulose acetate is plasticized separately with triethyl citrate and combined with the molten precursor. The resulting melt is passed through an extruder and spinneret and drawn into fibers (see Figure 1 ).

[0041] In another embodiment, partially cured poly(octanedioic acid sebacate) containing baking soda is hot pressed with cellulose acetate and molded into a specific shape. Upon heating, the baking soda reacts with the citric acid to produce pores and, thus, a foam structure. The resulting material can be incorporated into a wide variety of articles, such as, for example, but not limited to, shoes, clothing, and other apparel.

[0042] In one embodiment, the method comprises: combining equimolar amounts of caprylyl glycol, sebacic acid, and citric acid and melting at 80° C. to a honey-like consistency to form a molten precursor; plasticizing cellulose acetate with triethyl citrate and combining with the molten precursor to form a melt; and passing the melt through an extruder and spinneret and drawing into fibers.

[0043] In another embodiment, the method comprises combining equimolar amounts of caprylyl glycol, sebacic acid, and citric acid and melting at 80° C. to form a partially cured poly(octylene citrate sebacate); hot pressing the partially cured poly(octylene citrate sebacate) containing baking soda with cellulose acetate to mold into a desired shape; and heating to react the baking soda with the citric acid to generate pores, thereby forming a foam structure.

[0044] In another embodiment, the method comprises: reacting a plurality of diacids and a plurality of diols together in the presence of a crosslinking agent to form a polyester, wherein the crosslinking agent comprises both a thermal initiator and a photoinitiator; pelletizing the polyester, and then melt-extruding or solution-extruding the pelletized polyester to form a thermoplastic fiber; and exposing the thermoplastic fiber to a UV chamber for a time sufficient to activate the unsaturated double bonds in the crosslinking agent and produce crosslinks (e.g., at least a few minutes), thereby producing an elastomeric fiber. In some such embodiments, the reaction comprises esterifying a plurality of diacids and a plurality of diols together, for example, to prevent crystallization and / or maximize elongation. In some such embodiments, the diol comprises propylene glycol, 1,4-butanediol, or a combination thereof. In some such embodiments, the diacid comprises sebacic acid, succinic acid, or a combination thereof.

[0045] In some embodiments, the bio-based compostable stretchable polymer further comprises a UV stabilizer, such as boric acid.

[0046] In some embodiments, the bio-based compostable stretchable polymer further comprises a thermal stabilizer, such as lignin.

[0047] In one embodiment, stretchable polymers are provided that provide a sustainable alternative or replacement for elastic fibers. In some such embodiments, the stretchable polymer is composed entirely of natural biomolecules, e.g., is 100% bio-based and compostable.

[0048] In one embodiment, a bio-based compostable stretchable polymer is provided.

[0049] In one embodiment, a bio-based compostable stretchable polymer having an elongation of 200% is provided.

[0050] In one embodiment, a bio-based compostable stretchable polymer having an elongation of up to 600% is provided.

[0051] In one embodiment, a biobased compostable stretchable polymer having a tenacity of at least 5 g / denier is provided.

[0052] In one embodiment, bio-based compostable stretchable fibers having a denier size of about 25 to about 40, about 25, or about 40 are provided.

[0053] In one embodiment, a bio-based compostable stretchable polymer with full elastic recovery is provided.

[0054] In one embodiment, a bio-based compostable stretchable polymer is provided that is stable over multiple wash cycles.

[0055] In one embodiment, a bio-based compostable stretchable polymer is provided that can be processed via suitable melt spinning.

[0056] In one embodiment, a bio-based compostable stretchable polymer formed by extrusion followed by curing with UV light is provided.

[0057] In one embodiment, a bio-based compostable stretchable polymer is provided that can be formed into ultrafine fibers (eg, fibers of at least 40 denier), such as via melt spinning or dry spinning.

[0058] In one embodiment, a bio-based compostable stretchable polymer is provided that can be easily separated from a blend at the end of its life via mild hydrolysis. For example, but not by way of limitation, an increase in pH can cause the polymer to hydrolyze into its monomers. The recovered monomers can be further reacted to form new polymers and can be reprocessed into fibers without degradation, thereby facilitating recycling.

[0059] Also provided are fibers, foams, and molded articles comprising the biobased compostable stretchable polymers of the present disclosure.

[0060] Also provided are articles comprising the bio-based compostable stretchable polymers of the present disclosure, and fibers, foams, and molded articles thereof.

[0061] Further aspects and features of the technology are described in the detailed description that follows. BRIEF DESCRIPTION OF THE DRAWINGS

[0062] This patent or application file contains at least one drawing executed in color. Copies of this patent or patent application publication with color drawing(s) will be provided by the Department upon request and payment of the necessary fee.

[0063] For a better understanding of the invention and to show more clearly how it may be carried into effect, reference will now be made, by way of example, to the accompanying drawings which illustrate aspects and features of embodiments according to the invention, and in which:

[0064] Figure 1 is a schematic diagram illustrating a scheme for preparing a bioelastomer according to certain embodiments of the present technology.

[0065] Figure 2Shown are graphs of stress (MPa) at 50% strain vs. cycles for the tested bioelastomers OS-GE07 (bottom line, orange) and OS-GE08 (top line, green), indicating the maximum force applied to reach 50% strain during each cycle (n=3).

[0066] Figure 3 Shown is a graph of strain (%) vs. cycles at 0 MPa for the test bioelastomer OS-GE07, indicating the unrecovered elongation remaining at the start of each cycle (n=3).

[0067] Figure 4 is a schematic diagram illustrating a method for making foam from a bioelastomer, according to certain embodiments.

[0068] Figure 5 is a photograph illustrating biofoam produced from bioelastomer according to certain embodiments.

[0069] Figure 6 Shown are photographs of biofoams produced from bioelastomers of the present disclosure, according to certain embodiments. The foams depicted are, from left to right, Foam 1, Foam 2, Foam 3, Foam 4, and Foam 5. DETAILED DESCRIPTION

[0070] The terminology used in the description of the various described embodiments herein is for the purpose of describing particular embodiments only and is not intended to be limiting.

[0071] In order to provide a clear and consistent understanding of the terms used in this specification, a number of definitions are provided below. In addition, unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs.

[0072] definition

[0073] As used herein, when used in combination with the term "comprising" in the claims and / or the specification, the use of the word without a quantifier can mean "one", but it is also consistent with the meaning of "one or more", "at least one", and "one or more than one". Similarly, the word "another" can mean at least a second or more.

[0074] As used herein, the words "comprises" (and any variations thereof), "having" (and any variations thereof), "includes" (and any variations thereof), and "containing" (and any variations thereof) are inclusive or open-ended and do not exclude additional unrecited elements or process steps.

[0075] The term "about" is used to indicate that a value includes the inherent variation of error for the device or method being employed to determine the value.

[0076] As used herein, when an amount is indicated as being present "on a weight basis" or as "weight percent (wt. %)" or "by weight," the amount is measured as the weight percent of one or more components expressed on a dry basis (by taking into account the moisture percentage in each component) relative to the total weight of all components present in the composition.

[0077] As used herein, the term "derivative" is understood to mean a substance that is structurally similar to another compound but differs in some minor structural details.

[0078] As used herein, the term "polymer" refers to a material comprising a group of macromolecules. The macromolecules contained in the polymer can be identical, or can be different from each other in some way. The macromolecule can have any one of a variety of backbone structures, and can include one or more types of monomeric units. In particular, the macromolecule can have a linear or nonlinear backbone structure. Examples of nonlinear backbone structures include branched backbone structures, such as those with star-shaped branches, comb-shaped branches or dendritic branches, and network backbone structures. The macromolecules contained in the homopolymer usually include one type of monomeric unit, while the macromolecules contained in the copolymer usually include two or more types of monomeric units. Examples of copolymers include statistical copolymers, random copolymers, alternating copolymers, periodic copolymers, block copolymers, star copolymers and graft copolymers.

[0079] In some cases, the reactivity and functionality of the polymer can be altered by adding a set of functional groups, such as anhydride groups, amino groups and their salts, N-substituted amino groups, amide groups, carbonyl groups, carboxyl groups and their salts, cyclohexyl epoxy groups, epoxy groups, glycidyl groups, hydroxyl groups, isocyanate groups, urea groups, aldehyde groups, ester groups, ether groups, alkenyl groups, alkynyl groups, thiol groups, disulfide groups, silyl or silane groups, groups based on glyoxal, groups based on aziridine, groups based on active methylene compounds or other b-dicarbonyl compounds (such as 2,4-pentanedione, malonic acid, acetylacetone, ethylacetone acetate, malonamide, acetoacetamide and its methyl analogs, ethyl acetoacetate and isopropyl acetoacetate), halogen groups, hydrides or other polar or H-bonding groups, and combinations thereof. Such functional groups can be added at various locations along the polymer, for example, randomly or regularly dispersed along the polymer, at the ends of the polymer, attached as independent pendant groups to the polymer, or directly attached to the polymer backbone. In addition, the polymer may be capable of cross-linking, entanglement, or hydrogen bonding to increase its mechanical strength or its resistance to degradation under environmental or processing conditions.

[0080] "Polymerization" is the process of reacting monomer molecules together in a chemical reaction to form a three-dimensional network or polymer chain. As is known in the art, many forms of polymerization are known, and different systems exist to classify them.

[0081] As can be appreciated, polymer can be provided in a variety of forms with different molecular weights, because the molecular weight (molecular weight, MW) of polymer can depend on the processing conditions for forming polymer. Therefore, polymer can be referred to as having a specific molecular weight or molecular weight range. As used herein about polymer, the term "molecular weight (MW)" can refer to number-average molecular weight or weight-average molecular weight. Polymer is usually represented by its average MW, for example PEG1000 refers to a PEG with an average MW of 1000. Polymer can also be represented by its degree of polymerization (" n "), which can be generally in the range of as low as 40 to as high as 5000. In some cases, polymers of different molecular weights can be mixed to obtain a composition with desired properties. It should be understood that a mixture of polymers of any molecular weight or polymers of different molecular weights can be used, as long as the resulting composition has desired properties or is generally suitable for purposes as described herein, as will be determined by the skilled person using known techniques.

[0082] As used herein, the term "copolymer" refers to a polymer having two or more different divalent monomer units.

[0083] As used herein, the term "chemical bond" refers to the coupling of two or more atoms based on attractive interactions so that these atoms can form a stable structure. Examples of chemical bonds include covalent bonds and ionic bonds. Other examples of chemical bonds include hydrogen bonds and attractive interactions between carboxyl groups and amine groups. As used herein, the term "covalent bond" means a form of chemical bonding characterized by sharing electron pairs between atoms or between atoms and other covalent bonds. When atoms share electrons, the attraction and repulsion stability formed between atoms is called covalent bonding. Covalent bonding includes many types of interactions, including σ bonding, π bonding, metal-metal bonding, agostic interactions, and three-center two-electron bonds.

[0084] As used herein, the term "reactive functional group" means a chemical group (or moiety) that is capable of reacting with another chemical group to form a covalent bond or an electrovalent bond, examples of which are given above. Preferably, such a reaction is feasible at relatively low temperatures (e.g., below 200° C., more preferably below 100° C.) and / or under conditions suitable for treating delicate substrates (e.g., textiles). The reactive functional group can have a variety of chemical properties. For example, the reactive functional group can react with reactive functional groups of a variety of substrates (e.g., cotton, wool, fur, leather, polyester, or textiles made of such materials and other base materials) and form electrovalent bonds or covalent bonds.

[0085] As used herein, the term "compostable" refers to an organic matter that is completely decomposed into non-toxic components (e.g., water, carbon dioxide, and biomass) during composting by a biological process and does not harm the environment (i.e., does not leave toxic residues). As used herein, the term "biodegradable" means a material that decomposes and degrades in the environment. Although all compostable materials are biodegradable, not all biodegradable materials are compostable. Different from compostable items (because compostable items are already organic matter, therefore, they do not leave toxic residues), some biodegradable products may take several years to decompose and may leave toxic waste in some cases.

[0086] As used herein, the term "biobased" refers to materials made from substances derived from organic matter, ie, biological materials, plants, or other renewable agricultural, marine, and forestry materials.

[0087] Example

[0088] The present invention will be more readily understood by reference to the following examples, which are provided to illustrate the invention and are not to be construed as limiting its scope in any way.

[0089] Unless otherwise defined or the context clearly dictates otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which the invention belongs. It should be understood that any methods and materials similar or equivalent to those described herein can be used in the practice or testing of the present invention.

[0090] Example 1. Separation test via pH change.

[0091] Objectives. To conduct tests to determine the minimum conditions for depolymerization of bioelastomers; to verify that increasing surface area results in faster degradation; to verify that degradation conditions do not affect cotton and polyester; and to evaluate the effects of household laundry detergents on bioelastomers.

[0092] Materials. The following materials were used: bioelastomer: OS-GE07-3; 3 blocks: (127 ± 2 mg) prisms, approximately 6 × 4 × 2 mm; long pieces: 128 mg strips, approximately 40 × 1 × 1 mm; fabrics: cotton (130 mg simple woven fabric, approximately 2 × 2 cm), PE (80% polyester, 20% nylon, 165 mg composite woven fabric, approximately 2 × 2 cm); test solutions: pH 13 buffer (K2HPO4 0.1 M (pH 13.3) adjusted with NaOH), pH 12 buffer (Na2CO3 0.1 M (pH 11.8)); and detergent: Arm & Hammer cold wash laundry detergent (pH 11.2) diluted 1:50.

[0093] The samples are shown in Table 1.

[0094] Table 1. Samples.

[0095] mark sample Mass (mg) solution A1 Block bioelastomer 127 pH 13.3 buffer A2 Long bioelastomer 128 pH 13.3 buffer A3 cotton 130 pH 13.3 buffer B1 Block bioelastomer 125 pH 11.8 buffer C1 Block bioelastomer 129 detergent PE PE 165 pH 13.3 buffer

[0096] Testing. For the first test, samples A, B, and C were placed in their test solutions and the samples were left at room temperature for 2 hours. The samples were checked and agitated every 30 minutes ("Room Temperature Test"). After the first test, the same test tubes were transferred to a 90°C water bath for 1.5 hours. The samples were checked and agitated every 30 minutes ("High Temperature Test"). As an additional test the following day, a piece of PE / nylon fabric was placed in a pH 13.3 buffer and stored at 55°C for 3 hours. The samples were removed and checked at the 1 hour mark before continuing the test ("Polyester Test").

[0097] Results of room temperature testing. The bioelastomers (samples A1, A2) turned yellow shortly after entering the pH 13.3 solution. They did not appear to be affected in other ways. The samples gained weight after their surfaces dried, which could be due to water absorption or due to the yellowing phenomenon. The elongated sample (A2) gained more weight than A1 (41% v. 18%), which suggests a surface-dependent effect. The cotton sheet (sample A3) was unaffected by the test. When the bioelastomer (B1) was placed in the pH 11.8 solution, it did not change. At the end of the 2-hour test, it had a light yellow hue and had gained a little weight (8%). The bioelastomer (C1) did not appear to be affected by the room temperature laundry detergent.

[0098] Results of the high temperature test. The bioelastomers (samples A1, A2) were completely dissolved in a pH 13.3 solution at 90°C after about 45 minutes for the thin sample (A2) and after 1.5 hours for the block sample (A1). The cotton sheet (A3) was not affected by the test. The bioelastomer (B1) swelled and became transparent during the test. After being removed from the solution, B1 gained a lot of weight (180%). The next day, B1 had shrunk, turned slightly yellow, and its weight had dropped to 45% of its initial weight. The bioelastomer (C1) swelled and became whiter. After being removed, it was spongy and sticky, with a weight increase of 24%. The next day, the C1 sample returned to its original weight, with a slightly whiter color.

[0099] Results of the polyester test. The polyester samples were not affected by the test.

[0100] Analysis. There were no observable effects from subjecting cotton or polyester to degradation conditions. At 90°C at pH 13.3, there was complete dissolution of the bioelastomer. The time required depended on the geometry, with higher surface area resulting in faster dissolution. At 90°C at pH 11.8, there was degradation of the bioelastomer, but it was slower than at pH 13.3. At room temperature, the bioelastomer did not appear to be affected by laundry detergent. At 90°C, we did observe some interaction between the samples. The bioelastomer did absorb some water, especially at higher pH and temperature, and this water evaporated when left at rest under ambient conditions.

[0101] Example 2. Preparation of bioelastomer.

[0102] Introduction. The biodegradable elastomers prepared herein are based on a family of biodegradable polyesters and represent a new generation of synthetic biomaterials. They contain highly biocompatible, biodegradable components such as citric acid (CA) and sebacic acid (SA). When these polyfunctional acids react with polyfunctional alcohols in a catalyst-free polyesterification reaction, they produce polyesters with high elasticity.

[0103] The protocol for the preparation of bioelastomers is Figure 1 Schematically shown in FIG. Components A, B, and C are mixed in a container according to their respective molar amounts. The container is placed in a 165°C oil bath for 15 minutes to ensure that all components are melted. The reaction temperature is lowered to 145°C, and the mixture is gently stirred for 1 hour. The hot mixture is transferred to a silicone dish and placed in a vacuum oven at 120°C for 20 to 24 hours. The resulting bioelastomer is washed several times with water to remove unreacted monomers.

[0104] Example 3. Bioelastomer characterization.

[0105] One of the objectives of this technology is to replace conventional spandex (e.g., spandex, Lycra) with biodegradable bio-based elastomers. TM Spandex is a polyurethane-based fiber, primarily produced by melt spinning or solvent spinning from macromolecular diols and cyclic diisocyanates. Its physical properties can be adjusted by the components used.

[0106] Typical conventional spandex monofilaments may exhibit the following properties: an elongation at break of 200% to 550%; a tenacity of 0.9 g / denier; an elastic modulus of 0.05 g / denier; a 95% recovery of strain within a cycle at 100% elongation; a 10% rest hysteresis after 5 cycles at 200% elongation; and / or a permanent set of 10% to 17% after 50,000 cycles.

[0107] Testing Procedure. The bioelastomers were tested as described herein.

[0108] Tensile measurements were performed using an Instron universal testing machine equipped with a 50N load cell. The specimens were cut into straight sections approximately 4 mm wide, 1.5 mm thick, and 10 cm long. The specimens were held by two 25 mm clamps placed 30 mm apart. The tensile load was measured while the material was stretched at a constant rate of 50 mm / min. An Instron Blue Hill TM The software calculates tensile stress, tensile strain, and Young's modulus.

[0109] Elastic recovery was assessed by measuring 10 consecutive stretch-relaxation cycles. The specimen was stretched at 100% / min to 50% strain and then relaxed back to 0% at the same rate. The maximum tensile stress of each cycle was recorded.

[0110] Physical properties. Evaluate tensile properties, cyclability, and elastic recovery.

[0111] (1) Tensile properties. Lab-scale tensile measurements of both OS-GE07 and OS-GE08 showed that the elastic properties were comparable to the expected range of the initial specifications (greater than 100%). OS-GE08 is similar to OS-GE07, but has a 25% higher degree of cure. OS-GE07 can be stretched further, while OS-GE08 requires more tension to stretch. Combining components from these materials will allow for tuning of properties. As the soft segment length increases, we observe a direct correlation between segment length, yield tensile strength, and Young's modulus. The results are given in Table 2.

[0112] Table 2. Tensile properties measured on laboratory scale samples (n=3).

[0113]

[0114] (2) Cyclic performance. Tests have shown that the stress required to stretch the test material to 50% strain does not decrease over 10 cycles ( Figure 2 ). This result indicates that the elastic force is maintained over the cycle. This observation is comparable to spandex, for which 95% of the elastic strain is maintained over the cycle.

[0115] (3) Elastic recovery. The test also showed that the test material did not immediately recover to its original length after the stretch-relaxation cycle ( Figure 3 This hysteresis does accumulate within 10 cycles, indicating a recovery time longer than the several seconds allowed by the test. This observed value is comparable to some spandex fibers and textiles. The tensile set of the material can also be measured using a procedure based on ASTM D412.

[0116] Example 4. Origin and end of life of raw materials.

[0117] Citric acid. Citric acid is abundant in citrus fruits (such as oranges, limes and lemons). Its concentration in the latter can reach up to 300mmol / L. Although abundant in citrus fruits, citric acid is a ubiquitous compound. For example, it is an intermediate in the Krebs cycle (Krebs Cycle) (also known as tricarboxylic acid or TCA cycle), which allows the oxidation of acetyl-CoA to produce energy by anaerobic or aerobic respiration. It is industrially produced by extracting from lemon juice or by carrying out fungal fermentation with mold strains (such as Penicillium or Aspergillus niger). Fungal fermentation is generally a popular production route because it is a fast and inexpensive path that can be carried out by carbohydrates or industrial residues (such as corn steep liquor).

[0118] Sebacic acid. Sebacic acid is a naturally occurring dicarboxylic acid. It is obtained by alkaline cleavage of ricinoleic acid under pressure. Ricinoleic acid is the main component of castor oil (accounting for up to 87% of its composition). Castor oil is extracted from castor beans.

[0119] Octanediol-1,8. Octanediol is produced by hydrogenation of suberic acid. Suberic acid occurs naturally in cork bark. Industrially, suberic acid is primarily produced from cyclooctene, a petroleum-based compound. However, suberic acid can also be produced from bio-based materials through ozonolysis of palmitic acid or by cleavage of ricinoleic acid through nitrous acid treatment.

[0120] Decanediol-1,10. This compound is produced industrially by hydrogenation of sebacic acid.

[0121] Example 5. Production of foam from the bioelastomers of the present disclosure.

[0122] Method. The method for making foam from the test bioelastomer of the present disclosure is Figure 4 First, as Figure 4 As shown in the first step, citric acid, sebacic acid and octanediol are mixed in equimolar proportions and heated for pre-curing. Thereafter, baking soda is introduced as a foaming agent to generate pores. Figure 4 In step 3, the resulting sheet is cured in an oven and finally thermoformed to the desired shape. A photograph of such a foam is shown in Figure 5 middle.

[0123] Example 6. Preparation of foam from the bioelastomer of the present disclosure.

[0124] Foams were prepared from the bioelastomers of the present disclosure as described in Tables 3 and 4. A photograph of an exemplary foam made as described in Table 3 is shown in Figure 6 , which shows Foam 1, Foam 2, Foam 3, Foam 4 and Foam 5 from left to right.

[0125] Table 3. Exemplary foams prepared from bioelastomers of the present disclosure, according to certain embodiments.

[0126]

[0127]

[0128] Table 4. Exemplary foams prepared from bioelastomers of the present disclosure, according to certain embodiments.

[0129]

[0130]

[0131] Although the invention has been described in detail with reference to embodiments thereof, these embodiments are provided to illustrate and not to limit the invention. Other embodiments may be made which employ the principles of the invention and fall within the spirit and scope defined by the appended claims.

[0132] Based on the foregoing, those skilled in the art will readily appreciate that various modifications and changes may be made to various embodiments without strictly following the exemplary embodiments and applications shown and described herein. Such modifications do not depart from the true spirit and scope of various aspects of this disclosure, including those set forth in the claims.

[0133] The contents of all documents and references cited herein are hereby incorporated by reference in their entirety.

Claims

1. A stretchable polymer made by reacting one or more diols with a diacid or triacid, followed by curing at elevated temperature.

2. A stretchable polymer made by reacting a diol with a diacid in the presence of a cross-linking agent comprising both a thermal initiator and a photoinitiator, followed by extrusion and subsequent curing with ultraviolet light (UV).

3. The stretchable polymer according to claim 2, wherein the cross-linking agent is itaconic acid, maleic acid, maleic anhydride or a combination thereof.

4. A stretchable polymer according to any one of claims 1 to 3, wherein the polymer exhibits an elongation of at least 50%.

5. A stretchable polymer according to any one of claims 1 to 4, wherein the polymer exhibits a maximum elongation of 1000%.

6. The stretchable polymer of any one of claims 1 to 5, wherein the polymer has a tenacity of at least 5 g / denier.

7. A stretchable polymer according to any one of claims 1 to 6, wherein the polymer fully recovers its original length after the stress is removed.

8. The stretchable polymer according to any one of claims 1 to 7, wherein the polymer is capable of undergoing at least 100 relaxation and elongation cycles without any fatigue.

9. The stretchable polymer according to any one of claims 1 to 8, wherein the diol is 1,4-butanediol, pentanediol, hexanediol, octanediol, decanediol or dodecanediol.

10. The stretchable polymer according to any one of claims 1 to 9, wherein the diacid is sebacic acid, succinic acid, adipic acid, lactic acid or boric acid.

11. The stretchable polymer according to any one of claims 1 to 10, further comprising a cross-linking agent.

12. The stretchable polymer according to claim 11, wherein the cross-linking agent is citric acid or boric acid.

13. The stretchable polymer of claim 11, wherein the cross-linking agent is itaconic acid, maleic acid or maleic anhydride.

14. A stretchable polymer according to claim 11 or 13, wherein the cross-linking agent comprises unsaturated bonds that can be activated thermally and / or by UV.

15. The stretchable polymer of any one of claims 11, 13, and 14, wherein the polymer comprises: - one or more diacids; - one or more diols; and - a cross-linking agent comprising a thermal initiator and a photoinitiator, wherein the cross-linking agent is itaconic acid or maleic acid; wherein the polymer is formed by: (i) reacting the one or more diols with the one or more diacids to form a polyester; (ii) pelletizing the polyester, and then melt-extruding or solution-extruding the pelletized polyester to form thermoplastic fibers; (iii) exposing the thermoplastic fibers to a UV chamber for at least several minutes to activate the unsaturated double bonds and produce crosslinks to form elastomeric fibers of the polymer.

16. The stretchable polymer of claim 15, wherein the elastomeric fiber has an elongation of at least 200% and is an ultrafine fiber of at least 40 denier formed via melt spinning or dry spinning.

17. A stretchable polymer according to any one of claims 1 to 16, wherein the polymer is in the form of melt-extruded fibers suitable for conversion into knitted or woven fabrics.

18. A stretchable polymer according to any one of claims 15 to 17, wherein the fibres are blended with cotton, polyester or nylon.

19. The stretchable polymer of any one of claims 15 to 18, wherein the fibers have one or more of the following properties: - capable of being converted into a knitted or woven fabric having high stretchability, e.g. at least 200% elongation and full elastic recovery; and - can be separated into monomers using a medium having a high pH, ​​for example a pH of 11 to 13, wherein the monomers can be reused to spin new fibers, thus allowing the recovery of the polymer.

20. A stretchable polymer according to any one of claims 1 to 19, further comprising one or more reinforcing agents added to improve stiffness and / or fracture resistance.

21. The stretchable polymer of claim 20, wherein the one or more reinforcing agents comprise microcrystalline cellulose, nanocrystalline cellulose, titanium dioxide, kaolin, silica, nanoclay, carbon black, or a combination thereof.

22. A stretchable polymer according to any one of claims 1 to 21, wherein the polymer is blended with a carrier polymer to obtain a viscosity and consistency suitable for processing into fibres or foams.

23. The stretchable polymer of claim 22, wherein the carrier polymer is cellulose, a cellulose derivative, poly(lactic acid), polycaprolactam, starch or another biopolymer.

24. A stretchable polymer according to any one of claims 1 to 23, wherein the polymer is capable of being processed into fibres via melt spinning, solution spinning, electrospinning or melt blowing.

25. A stretchable polymer according to any one of claims 1 to 24, wherein the polymer is capable of being formed into ultrafine fibres, such as fibres of at least 40 denier, via melt spinning or dry spinning.

26. The stretchable polymer of claim 24, wherein the fiber has a size ranging from 50 denier to 150 denier.

27. A stretchable polymer according to any one of claims 24 to 26, wherein the fibres are capable of being woven or knitted with cotton, polyester or other fibres to form a stretch fabric.

28. The stretchable polymer of claim 27, wherein the stretch fabric remains intact after 25 wash, rinse and / or dry cycles without loss of quality or physical properties.

29. A stretchable polymer according to any one of claims 1 to 28, wherein the polymer is capable of being formed into an article via injection moulding or 3D printing.

30. A stretchable polymer according to any one of claims 1 to 29, wherein the polymer can be made into a reticulated structure or foam by introducing a blowing agent.

31. The stretchable polymer of claim 30, wherein the polymer is thermoformable at elevated temperatures.

32. A stretchable polymer according to any one of claims 1 to 31, wherein the polymer is made partly or entirely from molecules of plant origin.

33. A stretchable polymer according to any one of claims 1 to 32, wherein the polymer is fully biodegradable at the end of its life.

34. A stretchable polymer according to any one of claims 1 to 33, wherein the polymer is fully compostable at the end of its life.

35. A stretchable polymer according to any one of claims 1 to 34, wherein the polymer is fully recyclable at the end of its life.

36. A stretchable polymer according to any one of claims 1 to 35, wherein the polymer is separable from a blend via an increase in pH.

37. A stretchable polymer according to claim 36, wherein the increase in pH causes the polymer to hydrolyze into its monomers.

38. A stretchable polymer according to claim 37, wherein the monomers are capable of further reacting to form new polymers.

39. A stretchable polymer according to any one of claims 36 to 38, wherein the polymer is recyclable.

40. A stretchable polymer according to any one of claims 1 to 39, wherein the polymer is suitable for use in clothing, underwear, automotive interiors, medical textiles and / or wound dressings in place of fibres.

41. The stretchable polymer of any one of claims 1 to 39, wherein the polymer is suitable for use in insulation applications, packaging applications, and clothing applications in place of polyurethane foam.

42. A stretchable polymer according to any one of claims 1 to 39, wherein the polymer is suitable for use in place of poly(dimethylsilicone) in moulded elastomeric articles.

43. The stretchable polymer of claim 42, wherein the molded elastomeric article is a cell phone case, a sealant, or a household item.

44. The stretchable polymer of claim 43, wherein the household item is a mattress or furniture.

45. The stretchable polymer of any one of claims 1 to 44, wherein the polymer comprises polyglyceryl sebacate (PGS) or polycaprylyl citrate (POC): Polyglyceryl Sebacate (PGS) Polyoctyl citrate (POC).

46. ​​The stretchable polymer according to any one of claims 22 to 45, wherein the carrier polymer is cellulose acetate (CA): Cellulose acetate (CA).

47. A fiber comprising the stretchable polymer of any one of claims 1 to 46.

48. A foam comprising the stretchable polymer according to any one of claims 1 to 46.

49. A moulded article comprising the stretchable polymer according to any one of claims 1 to 46.

50. An article comprising the stretchable polymer of any one of claims 1 to 46, the fiber of claim 47, the foam of claim 48, or the molded article of claim 49.

51. The article of claim 50, wherein the article is clothing, underwear, automotive interior, medical textile, wound dressing, insulation, packaging, cell phone housing, sealant, household goods, mattress, or furniture.

52. The article of claim 50, wherein the article is a knitted or woven fabric.

53. The article of claim 52, wherein the knitted or woven fabric is a stretch fabric.

54. A biodegradable and compostable bio-based elastomeric fiber having an elongation of at least 50% and a maximum elongation of 1000%, capable of fully recovering its original length after removal of stress, and capable of undergoing at least 100 cycles of relaxation and extension without any fatigue.

55. The elastomeric fiber of claim 54 wherein the polymer has a tenacity of at least 5 g / denier and / or wherein the fiber has a denier size of at least 40.

56. The elastomeric fiber of claim 54 or 55 comprising a diol reacted with a diacid or triacid and cured at elevated temperature.

57. The elastomeric fiber of any one of claims 54 to 56, comprising polyglyceryl sebacate (PGS) or polycaprylyl citrate (POC), and optionally further comprising a carrier polymer that is cellulose acetate (CA).

58. The elastomeric fiber of any one of claims 54 to 57, comprising a combination of a plurality of diacids and a plurality of diols esterified together.

59. The elastomeric fiber of claim 58, wherein the esterification prevents crystallization and / or maximizes the elongation of the fiber.

60. The elastomeric fiber of claim 58 or 59, wherein the plurality of glycols comprises propylene glycol and / or 1,4 butanediol.

61. The elastomeric fiber of any one of claims 58 to 60, wherein the plurality of diacids comprises sebacic acid and / or succinic acid.

62. A method for preparing an elastomeric fiber according to any one of claims 54 to 61, comprising: - Equimolar amounts of caprylyl glycol, sebacic acid, and citric acid were combined and melted at 80°C to a honey-like consistency to form a molten precursor; - plasticizing cellulose acetate with triethyl citrate and combining with the molten precursor to form a melt; and - The melt is passed through an extruder and spinneret and drawn into fibers.

63. A method for making a foam structure comprising an elastomer according to any one of claims 54 to 61, comprising: - Equimolar amounts of caprylyl glycol, sebacic acid, and citric acid were combined and melted at 80° C. to form partially cured poly(octylene glycol citrate sebacate); - hot pressing the partially cured poly(octanediol citrate sebacate) containing baking soda and cellulose acetate into a desired shape; - Heating causes the baking soda to react with the citric acid to create pores, thereby forming a foam structure.

64. The method of claim 63, further comprising adding a surfactant to ensure uniform distribution of cells in the foam structure.

65. The method of claim 64, wherein the surfactant is castor oil.

66. The method of claim 64 or 65, wherein the foam structure has an elongation at break of at least 150% and full elastic recovery.

67. A method for preparing an elastomeric fiber according to any one of claims 54 to 61, comprising: - reacting a plurality of diacids and a plurality of diols together in the presence of a cross-linking agent to form a polyester, wherein the cross-linking agent comprises both a thermal initiator and a photoinitiator; - pelletizing the polyester and then melt-extruding or solution-extruding the pelletized polyester to form thermoplastic fibers; and - Exposing the thermoplastic fiber to a UV chamber for a time sufficient to activate the unsaturated double bonds in the crosslinking agent and produce crosslinks, thereby producing the elastomeric fiber.

68. The method of claim 67, wherein the cross-linking agent is itaconic acid, maleic acid, or a combination thereof.

69. The method of claim 67 or 68, wherein the diol comprises propylene glycol, 1,4 butanediol, or a combination thereof.

70. The method of any one of claims 67 to 69, wherein the diacid comprises sebacic acid, succinic acid, or a combination thereof.

71. The method of any one of claims 67 to 70, wherein the plurality of diacids and plurality of diols are esterified together to prevent crystallization and / or maximize elongation.

Images