Thermoplastic polyurethane composition having shape memory properties

Abstract

The thermoplastic polyurethane composition having shape memory properties comprises the reaction product of a polyester polyol component comprising a short-chain diol and a dicarboxylic acid such as 2,5-furan dicarboxylic acid, a diisocyanate component, and a chain extender component. Thermoplastic polyurethanes (TPUs) are an excellent choice of material for many applications due to their excellent properties, including ease of processability, abrasion resistance, impact resistance, and chemical resistance, high flexibility and cut resistance, good environmental weathering resistance, and biocompatibility.

Description

[Technical Field]

[0001] The present invention relates to thermoplastic polyurethane (TPU) compositions having excellent shape memory and thermomechanical properties that can be used in molded articles. [Background technology]

[0002] Thermoplastic polyurethanes (TPUs) are an excellent choice of material for many applications due to their ease of processing and excellent properties, including abrasion, impact, and chemical resistance, high flexibility and cuttability, good environmental weathering resistance, and biocompatibility.

[0003] As is well known, TPUs are prepared by reacting a diisocyanate compound, a polymeric diol, and a difunctional chain extender. Typically, a large amount of diisocyanate and chain extender must be used to obtain a product with high hardness that maintains the material's mechanical properties. However, due to the high toxicity and environmental impact of diisocyanates, such high-hardness materials have a high environmental footprint. Therefore, the development of high-hardness materials with limited amounts of hazardous diisocyanates is particularly interesting for producing more environmentally friendly TPUs.

[0004] The development of thermally induced shape memory polymers (SMPs) has attracted interest due to their additional interesting properties such as recovery stress and energy output. These materials can switch from plastic to elastic deformation behavior when triggered by an external stimulus such as heat, light, or electricity. SMPs perform mechanical work when the switch in deformation behavior occurs. Specifically, the glass transition temperature (T g ) or melting transition temperature (T m Thermally activated SPMs that switch between both behaviors upon reaching either of these states can be utilized for many applications in different fields, such as medical implants or devices, smart actuators, or self-deploying structures.

[0005] Shape memory polymers and molded articles are disclosed, for example, in US Patent Application No. 2008221279 (A1) and US Patent Application No. 10907006 (B2). Nevertheless, there remains a general need in the state of the art for SMPs with lower toxicity, higher recovery stress and energy output. The present invention aims to meet some or all of these needs and to solve some or all of the problems identified above. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] US Patent Application Publication No. 2008 / 221279 [Patent Document 2] U.S. Patent No. 10,907,006 Summary of the Invention [Means for solving the problem]

[0007] The present invention relates to a thermoplastic polyurethane composition having shape memory properties.

[0008] In one aspect, the present invention provides a method for producing a pharmaceutical composition comprising: (a) a polyester polyol comprising a short chain diol and a dicarboxylic acid selected from the group consisting of 2,5-furandicarboxylic acid; (b) a diisocyanate component; and and (c) a chain extender component.

[0009] The thermoplastic polyurethane compositions are suitable for producing molded articles having shape memory properties.

[0010] In another aspect, the present invention relates to a shaped article comprising a thermoplastic polyurethane composition according to the first aspect.

[0011] The following embodiments of the present subject matter are contemplated. 1. A thermoplastic polyurethane composition comprising the reaction product of (a) a polyester polyol comprising a short-chain diol and 2,5-furandicarboxylic acid, (b) a diisocyanate component, and (c) a chain extender component. 2. The thermoplastic polyurethane composition of embodiment 1, wherein the polyester polyol has a number average molecular weight of less than 5,000 Da. 3. The thermoplastic polyurethane composition according to embodiment 1 or 2, wherein the polyester polyol has a number average molecular weight in the range of 800 to 5,000 Da, preferably 1,000 to 3,000 Da. 4. The thermoplastic polyurethane composition of any one of embodiments 1-3, wherein the diisocyanate is in an amount to provide an NCO:OH molar ratio of 1:1.25 to 1.25:1. 5. The thermoplastic polyurethane composition of any one of embodiments 1 to 4, wherein the molar ratio of chain extender to polyol is from 1:1 to 1:9. 6. The thermoplastic polyurethane composition of any one of embodiments 1 to 5, wherein the molar ratio of 2,5-furandicarboxylic acid to short-chain diol in the polyester polyol (a) is 1:1 to 1:5, or 1:1 to 1:2, or 1:1 to 1:1.5, or 1:1 to 1:1.25. 7. The thermoplastic polyurethane composition of any one of embodiments 1-6, wherein the short-chain diol is selected from the group consisting of 1,4-butanediol (BDO) and 1,6-hexanediol (HDO), 1,3-propanediol (PDO), or mixtures thereof. 8. The thermoplastic polyurethane composition of any one of embodiments 1-7, wherein the chain extender component comprises or consists of 1,4-butanediol. 9. The thermoplastic polyurethane composition of any one of embodiments 1-7, wherein the chain extender component comprises or consists of 1,3-propanediol (PDO), and optionally the diisocyanate component is selected from the group consisting of aromatic diisocyanates and aliphatic diisocyanates, or mixtures thereof. 10. The thermoplastic polyurethane composition of any one of embodiments 1-9, wherein the diisocyanate component is selected from diphenyl diisocyanate (MDI), hexamethylene diisocyanate (HDI), or a mixture thereof. 11. The thermoplastic polyurethane composition of any one of embodiments 1-10, wherein the diisocyanate component comprises or consists of MDI. 12. The thermoplastic polyurethane composition of any one of embodiments 1-11, wherein the diisocyanate component comprises or consists of HDI. 13. The thermoplastic polyurethane composition of any one of embodiments 1 to 12, wherein the thermoplastic polyurethane has a hard segment content of 2 to 50 wt % or 7 to 36 wt %. 14. The thermoplastic polyurethane composition of any one of the preceding embodiments, wherein the thermoplastic polyurethane exhibits a Shore D hardness, determined by ISO 7619-1:2010, of at least 60, or at least 70, or at least 80, or at least 86, or at least 90. 15. The thermoplastic polyurethane composition of any one of embodiments 1 to 14, wherein the thermoplastic polyurethane exhibits a recovery stress of 1 to 30 MPa, preferably 14 to 30 MPa. 16. The thermoplastic polyurethane composition of any one of embodiments 1 to 15, wherein the thermoplastic polyurethane exhibits an energy output of 0.6 to 30 MJ / m3 or 8 to 30 MJ / m3. 17. A molded article comprising the thermoplastic polyurethane composition of any one of embodiments 1-16. 18. The molded article of embodiment 17, wherein the moldable article is a medical device. DETAILED DESCRIPTION OF THE INVENTION

[0012] The articles "a" and "an" are used herein to refer to one or to more than one (i.e., to at least one) of the grammatical object of the article, unless the context clearly indicates otherwise. By way of example, "an element" means one element or more than one element.

[0013] Except in the examples, or where expressly indicated otherwise, all quantities in this description specifying amounts of ingredients, reaction conditions, molecular weights, number of carbon atoms, etc., should be understood to be modified by the word "about." As used herein, the term "about," for example, when referring to a measurable value (e.g., the amount or weight of a particular ingredient, or temperature), refers to a variation of ±20%, ±10%, ±5%, ±1%, ±0.5%, or particularly ±0.1% of the specified amount. Unless otherwise indicated, all quantities in this description specifying amounts or proportions of ingredients are by weight.

[0014] As used herein, the term "comprising" is inclusive or open-ended and does not exclude additional, unrecited elements or method steps, and is intended to encompass the phrases "consisting essentially of" and "consisting of" as alternative embodiments, where "consisting of" excludes any elements or steps not specified, and "consisting essentially of" permits the inclusion of additional, unrecited elements or steps that do not materially affect the essential or basic and novel characteristics of the composition or method under consideration.

[0015] Temperature-activated shape memory polymers are materials that can switch between a permanent shape and a pre-programmed temporary shape depending on their temperature. The material can be deformed and cooled below a temperature at which it switches to its temporary shape, which is preserved by the material until the temperature is raised again above the switching temperature.

[0016] The present invention provides shape memory TPU compositions with desired hardness, recovery stress, energy output, and temperature elasticity.

[0017] Polyester polyol component The polyester polyol includes a short chain diol and 2,5-furandicarboxylic acid (FDCA).

[0018] FDCA is a member of the furan class with two carboxy substituents at positions 2 and 5. FDCA is a renewable carboxylic acid that can be prepared from carbohydrates and is also found as a natural product, for example, in fungi such as Phomopsis velata.

[0019] Suitable short-chain diols include, for example, those having 2 to 12 carbon atoms. Suitable diols may include, for example, ethylene glycol, 1,2-propanediol, 1,3-propanediol (PDO), 1,3-butanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol (HDO), 2,2-dimethyl-1,3-propanediol, 1,4-cyclohexanedimethanol, decamethylene glycol, dodecamethylene glycol, and the like. In particular, the short-chain diol used in the present invention may be HDO, PDO, or a mixture thereof. In one embodiment, the short-chain diol comprises, or even consists essentially of, HDO. In one embodiment, the short-chain diol comprises, or even consists essentially of PDO.

[0020] In one embodiment, the number average molecular weight (M n ) is about 250 to about 5,000, for example, about 1,000 to about 3,000 Da. n teeth, 1H NMR end group analysis is determined through integration of the signals corresponding to the terminal CH2OH protons and the alpha ester protons.

[0021] In one embodiment, the molar ratio of 2,5-furandicarboxylic acid to short chain diol in polyester polyol (a) is from 1:1 to 1:5, or from 1:1 to 1:2, or from 1:1 to 1:1.5, or from 1:1 to 1:1.25.

[0022] Diisocyanate component The diisocyanate component of the present invention can be selected from any diisocyanate known to those skilled in the art. Useful polyisocyanates can be selected from aromatic or aliphatic polyisocyanates, or combinations thereof. Non-limiting examples of useful diisocyanates include aromatic diisocyanates such as 4,4'-methylenebis(phenylisocyanate) (MDI), 3,3'-dimethyl-4,4'-biphenylene diisocyanate (TODI), m-xylene diisocyanate (XDI), 1,4-phenylene diisocyanate, 1,5-naphthalene diisocyanate (NDI), and toluene diisocyanate (TDI), as well as isophorone diisocyanate (IPDI), 1,4-cyclohexyl diisocyanate (1,4-cyclohexyl diisocyanate), and the like. Examples of suitable diisocyanates include aliphatic diisocyanates such as 1,6-hexamethylene diisocyanate (HDI), 1,10-decamethylene diisocyanate, lysine diisocyanate (LDI), 1,4-butane diisocyanate (BDI), and 4,4'-dicyclohexylmethane diisocyanate (HI2MDI). Mixtures of two or more diisocyanates may be used. In particular, the diisocyanate may be MDI and / or HDI. More specifically, the diisocyanate component comprises or consists essentially of MDI. In some embodiments, the diisocyanate component comprises or even consists essentially of HDI.

[0023] The thermoplastic polyurethane composition can comprise the reaction product of a polyester polyol comprising a short-chain diol selected from the group consisting of PDO and HDO and 2,5-furandicarboxylic acid (FDCA), a diisocyanate component comprising or consisting essentially of MDI and / or HDI, and a chain extender.

[0024] In one embodiment, the thermoplastic polyurethane composition may comprise the reaction product of a polyester polyol comprising PDO and 2,5-furandicarboxylic acid (FDCA), a diisocyanate component selected from the group consisting of MDI and HDI or mixtures thereof, and a chain extender.

[0025] In another embodiment, the thermoplastic polyurethane composition may comprise or consist of the reaction product of a polyester polyol comprising, consisting essentially of, or consisting of PDO and 2,5-furandicarboxylic acid (FDCA), a diisocyanate component comprising or consisting of MDI, and a chain extender. In yet another embodiment, the thermoplastic polyurethane composition may comprise or consist of the reaction product of a polyester polyol comprising, consisting essentially of, or consisting of PDO and 2,5-furandicarboxylic acid (FDCA), a diisocyanate component comprising or consisting of HDI, and a chain extender.

[0026] In another embodiment, the thermoplastic polyurethane composition may comprise or consist of the reaction product of a polyester polyol comprising, consisting essentially of, or consisting of HDO and 2,5-furandicarboxylic acid (FDCA), a diisocyanate component comprising or consisting of HDI, and a chain extender. In another embodiment, the thermoplastic polyurethane may comprise or consist of the reaction product of a polyester polyol comprising, consisting essentially of, or consisting of HDO and 2,5-furandicarboxylic acid (FDCA), a diisocyanate component comprising or consisting of MDI, and a chain extender.

[0027] Chain extender Chain extenders are desirably used in the polyurethane formulations of the present invention to increase their molecular weight and also contribute to the formation of crystalline hard blocks, resulting in thermoplastic polyurethanes with desirable mechanical properties.

[0028] Suitable chain extenders include relatively small polyhydroxy compounds, such as lower aliphatic or short chain diols having 2 to 20, or 2 to 12, or 2 to 10 carbon atoms. Suitable examples include ethylene glycol, diethylene glycol, triethylene glycol, tetraethylene glycol, propylene glycol, dipropylene glycol, 1,4-butanediol (BDO), 1,6-hexamethylenediol (HDO), 1,3-butanediol, 1,5-pentanediol, neopentyl glycol, 1,4-cyclohexanedimethanol (CHDM), 2,2-bis[4-(2-hydroxyethoxy)phenyl]propane (HEPP), heptanediol, nonanediol, dodecanediol, 3-methyl-1,5-pentanediol, ethylenediamine, butanediamine, hexamethylenediamine, and hydroxyethyl resorcinol (HER), pentaspiroglycol. glycol (PSG), hydroquinone bis(2-hydroxy ethyl) ether hydroquinone (HQEE), dipropylene glycol (DPG), 2-methyl-1,3-propanediol, 2-butyl-2-ethyl-1,3-propanediol (BEPD), and the like, as well as mixtures thereof. In one embodiment, the chain extender comprises, or even consists essentially of, 1,4-butanediol (BDO).

[0029] The molar ratio of chain extender to polyol can be from 1:1 to 1:9.

[0030] The hard segment content of the thermoplastic polyurethane composition is defined as the combined weight percent of the diisocyanate component and the chain extender component.

[0031] One of the advantages of the TPU compositions of the present invention is that they exhibit high hardness even at low concentrations of hard segments.

[0032] Thus, in some embodiments of the present invention, the thermoplastic polyurethanes herein can have a hard segment content of 50 wt% or less. In particular, the hard segment content can be 2 wt% to 50 wt%, or 7 to 36 wt%.

[0033] In one embodiment, the thermoplastic polyurethane composition exhibits a Shore D hardness of at least 60, or at least 70, or at least 80, or at least 86, or at least 90, as determined by ISO 7619-1:2010.

[0034] The thermoplastic polyurethane composition can have a Shore D hardness as determined by ISO 7619-1:2010 of at least 61 and a hard segment content of 7 to 36 wt.%.

[0035] The thermoplastic polyurethane composition can have a molar ratio of chain extender to polyol of from 1:1 to 1:9.

[0036] In one embodiment, the diisocyanate is in an amount to provide an NCO:OH molar ratio of 1:1.25 to 1.25:1, especially 1:1.1 to 1.1:1.

[0037] In some embodiments, the TPU compositions of the present invention exhibit desirable elongation and strain properties. For example, the TPU compositions may have an ultimate tensile strength of at least 28 MPa and a strain of at least 11% when measured using a process according to ISO 37 1A, modified by using a speed of 5 mm / min at 21°C, using dumbbell specimens prepared according to ISO 37 1A. The TPU compositions also exhibit shape retention (R f ) and resilience (R r Shape fixity refers to the percentage of elongation induced in a material that is maintained at 20°C below the transition temperature of the material under no load after deformation into a temporary shape, and is calculated as follows:

[0038]

number

[0039]

number

[0040] The desirable properties of shape memory polymers include good recovery stress and energy output.These two properties define how much strength (recovery stress) and energy output (volumetric energy density) a material can generate when moving from temporary shape to permanent shape.The TPU compositions disclosed herein have been observed to exhibit recovery stress and energy output.

[0041] The TPU compositions disclosed herein can have a recovery stress of 1 to 30 MPa, particularly 14 to 30 MPa.

[0042] Based on the detailed examples, one skilled in the art can repeat the assay periodically to objectively determine the recovery stress of a TPU composition.

[0043] For example, to measure the recovery stress of a TPU composition, the recovery stress is calculated by measuring the glass transition temperature (T g This value is determined at a temperature 20°C above the T g corresponds to the stress of the material when stretched to 90% of its ultimate strain at a temperature 20°C higher than the specimen temperature and then relaxed at the fixed elongation for 5 minutes. g can be measured using a method according to ISO 11357-2. As used herein, T g was measured using IS 11357-2 but with a heating and cooling rate of 10°C / min.

[0044] The TPU compositions disclosed herein have a viscosity of 0.6 to 30 MJ / m 3 , specifically 8 to 30 MJ / m 3 , more specifically 20-30MJ / m 3 It can have an energy output (volumetric energy density) of

[0045] Based on the detailed examples, one skilled in the art can repeat the assay periodically to objectively determine the energy output of the TPU composition.

[0046] For example, to measure the energy output (volumetric energy density) of a TPU composition, the energy output is calculated as the extrapolated area between the recovery stress and its elongation, as reported by Copper et al. [Cooper, C et al. High Energy Density Shape Memory Polymers Using Strain-Induced Supramolecular Nanostructures. ACS Cent. Sci. 2021, 7(10), 1657-1667. https: / / doi.org / 10.1021 / acscentsci.1c00829] as follows:

[0047]

number

[0048] The TPU compositions of the present invention are formed by reacting a polyester polyol component with a hard segment component comprising a diisocyanate and a chain extender, and optionally a catalyst.

[0049] Three reactants (polyol polyester, diisocyanate, and chain extender) are reacted together to form the TPU in the present invention. Any known process for reacting three reactants can be used to make the TPU.

[0050] This process may be a so-called "one-shot" process, in which all three reactants are added to an extruder reactor and allowed to react. The reaction may involve melting the polyol at 140-180°C and adding the diisocyanate and chain extender, and optionally catalysts and / or additives.

[0051] Thus, in one embodiment, the process comprises melting the polyester polyol at a temperature of 140-180° C. to melt the polyester polyol and adding a diisocyanate and a chain extender. The process may further comprise adding a catalyst and / or additives.

[0052] TPUs can also be prepared using a prepolymer process. In the prepolymer method, a polyol intermediate is generally reacted with an equivalent excess of one or more diisocyanates to form a prepolymer solution having free or unreacted diisocyanates therein. The reaction is generally carried out at a temperature of about 80 to about 220°C, or about 150 to about 200°C, optionally in the presence of a suitable urethane catalyst. Subsequently, a chain extender is added in an amount generally equal to the isocyanate end groups and any free or unreacted diisocyanate compounds, as described above. The chain extension reaction temperature is generally about 180 to about 250°C, or about 200 to about 240°C. Typically, the prepolymer route can be carried out in any conventional device, including an extruder. In such an embodiment, the polyol intermediate is reacted with an equivalent excess of diisocyanates in the initial section of the extruder to form a prepolymer solution, and then the chain extender is added in a downstream section and reacted with the prepolymer solution. Any conventional extruder can be utilized, including extruders equipped with a barrier screw having a length to diameter ratio of at least 20, and in some embodiments at least 25.

[0053] Auxiliary Materials and Catalysts Optionally, catalysts, auxiliary materials, and / or additives may be used in the polyurethane reaction mixture of the present invention.

[0054] Any of the catalysts conventionally used or known in the art to catalyze the reaction of isocyanates with reactive hydrogen-containing compounds can be used for this purpose. Examples of suitable catalysts, which in particular promote the reaction between the NCO groups of the diisocyanate and the hydroxy groups of the polyol and the chain extender, are conventional tertiary amines known from the prior art, such as triethylamine, dimethylcyclohexylamine, N-methylmorpholine, N,N'-dimethylpiperazine, 2-(dimethylaminoethoxy)ethanol, diazabicyclo[2.2.2]octane, etc., and also in particular organometallic compounds such as titanate esters, iron compounds such as ferric acetylacetonate, bismuth compounds such as bismuth octoate, bismuth neodecanoate, bismuth laureate, tin compounds such as stannous diacetate, stannous dioctoate, stannous dilaurate, or dialkyltin salts of aliphatic carboxylic acids such as dibutyltin diacetate, dibutyltin dilaurate, phenylmercury propionate, lead octoate, iron acetylacetonate, magnesium acetylacetonate, etc. Mixtures of the above catalysts may be used as well.

[0055] Auxiliary substances and / or additives may also be added. Suitable non-limiting examples include lubricants, such as fatty acid esters, their metal soaps, fatty acid amides, fatty acid ester amides, and silicone compounds, antiblocking agents, inhibitors, stabilizers against hydrolysis, light, heat, and discoloration, flame retardants, flame retardants, dyes, pigments, inorganic and / or organic fillers, and reinforcing agents.

[0056] Purpose The thermoplastic polyurethane (TPU) compositions described above are highly useful materials that can offer an attractive combination of physical properties, particularly mechanical and shape memory properties.

[0057] The composition of the present invention and any blends thereof are useful in a wide variety of applications.Non-limiting examples of articles containing the TPU composition of the present invention include cooking and storage utensils, furniture, automotive parts, toys, sportswear, medical devices, eyeglasses including eyeglass frames and temple pieces, sterilizable medical devices, sterilization containers, fibers, woven fabrics, nonwoven fabrics, drapes, gowns, filters, hygiene products, diapers, and articles such as films, oriented films, sheets, tubes, pipes, wire jackets, cable jackets, agricultural films, geomembranes, sporting goods, cast films, blown films, boat and marine parts, and other such articles.The composition may be suitable for automotive parts such as bumpers, grilles, trim parts, dashboards and instrument panels, exterior door and hood parts, spoilers, windscreens, windshield wipers, hubcaps, mirror housings, body panels, protective side moldings, and other interior and exterior parts related to automobiles, trucks, boats, and other vehicles.

[0058] Other useful articles can be formed from the compositions of the invention, including: crates, containers, packaging, laboratory equipment such as roller bottles and media bottles for culture growth, office floor mats, instrument sample holders and sample windows; liquid storage containers such as bags, pouches, and bottles for blood or solution storage and IV infusion; packaging materials, including packaging for any medical device or drug, including unit dose or other blister or bubble packs, and packaging materials for enclosing or containing food products to be stored by irradiation. Other useful items include medical tubing and valves for any medical device, including infusion kits, catheters, and respiratory therapy, as well as packaging materials for medical devices or food products to be irradiated, including trays, and containers for storing liquids, particularly water, milk, or juice, unit dose and bulk storage containers, and transport means such as tubing, hoses, pipes, etc., including their liners and / or jackets.

[0059] In the medical field, sutures can be created that have a shape-memory switching temperature near body temperature. These sutures tighten when they reach body temperature, securing the suture without the need for surgical intervention. Self-expanding shape-memory stents allow for the deployment of contracted stents that expand to their full size when placed in place and heated by body heat. This allows for easier insertion of the stent and minimizes harm caused during device introduction.

[0060] Lightweight self-deployable structures can also be created for smart buildings, such as in adaptive sunshades, or for aerospace applications, such as solar sails.

[0061] Articles can be made or prepared by any useful process for forming thermoplastic polyurethane materials, including at least molding, including compression molding, injection molding, blow molding, and transfer molding; film blowing or casting; extrusion and thermoforming; and lamination, pultrusion, draw reduction, rotational molding, spin bonding, melt spinning, melt blowing; fiber spinning, electrospinning, or combinations thereof. At least the use of thermoforming or film applications allows for the possibility of, and the derivation of benefits from, uniaxial or biaxial orientation of the material.

[0062] The present invention will be better understood by reference to the following examples, which serve to illustrate but not limit the invention. [Example]

[0063] Abbreviation The following abbreviations are used in the examples: MDI = 4,4'-methylenebis(phenylisocyanate) and HDI = 1,6-hexamethylene diisocyanate.

[0064] Synthesis of thermoplastic polyurethanes A series of different thermoplastic polyurethanes were synthesized using 1,4-butanediol as the chain extender as disclosed in Table 1. The NCO:OH ratio was 1:1. The Shore D hardness and glass transition temperature (T g ) was measured according to the following method. -Hardness calculated according to ISO 7619-1:2010 - glass transition temperature, T of the second cooling and heating g The data were obtained using a heating / cooling rate of 10°C / min.

[0065] Measured hardness and T g The values ​​are included in Table 1.

[0066] [Table 1-1]

[0067] [Table 1-2] 1

[0068] As a general trend, the hardness of TPUs with similar hard segment content is higher for FDCA than for standard TPUs with aliphatic polyols (i.e., ADPBDO), and even higher than for TPUs made with other aromatic polyols such as IPHTA. The same trend was observed for the glass transition temperatures.

[0069] Recovery stress / energy output / elasticity measurement The recovery stress, energy output, and elastic temperature were measured for each of the example TPU compositions.

[0070] Recovery stress and energy output were measured using a TA Instruments DMA Q800 to measure the T of each material on ISO37 1A dumbbell specimens. gThe stress was measured at a temperature 20°C higher than the maximum strain as described herein. To determine the recovery stress of the sample, the material was stretched to 90% of its maximum strain at a rate of 50% / min. The material was then allowed to relax under the fixed extension for 5 minutes, and the stress value after relaxation was selected as the recovery stress of the material.

[0071] The energy output (volumetric energy density) was calculated as the extrapolated area between the recovery stress and its elongation, as reported in Copper et al. [Cooper, C et al..High Energy Density Shape Memory Polymers Using Strain-Induced Supramolecular Nanostructures. ACS Cent. Sci. 2021, 7(10), 1657-1667. https: / / doi.org / 10.1021 / acscentsci.1c00829].

[0072]

number

[0073] The temperature-resistance characteristics of TPU compositions' mechanical properties have been studied using dynamic mechanical analysis (DMA). This resilience is important because the higher the resilience, the higher the material's maximum service temperature. Therefore, high resilience is required for applications requiring high-temperature resistance. Dynamic mechanical analysis (DMA) has been used to evaluate these temperature-resistance trends. This was done by using a modified ASTM D4045-06 test, in which the material was heated from -50°C at a rate of 5°C / min at a frequency of 1 Hz with a 10 μm amplitude on a dual cantilever clamp on a 35 x 15 x 2.5-3 mm sample, and determining the temperature at which the material reached a storage modulus of 5 MPa.

[0074] The results of the recovery stress, energy output, and elasticity measurements are listed in Table 2.

[0075] [Table 2]

[0076] For TPUs with similar compositions, the recovery stress and energy output were higher for the polymers containing FDCA. Furthermore, the elasticity versus temperature of the FDCA TPU was higher than for the IPHTA TPU.

[0077] The invention has been explained in relation to its preferred embodiments, and it is to be understood that various modifications thereof will become apparent to those skilled in the art upon reading the specification. It is therefore to be understood that the invention disclosed herein is intended to cover such modifications as fall within the scope of the appended claims.

Claims

1. 1. A thermoplastic polyurethane composition comprising: (a) a polyester polyol containing a short-chain diol and 2,5-furandicarboxylic acid; (b) a diisocyanate component; and (c) a chain extender component.

2. 10. The thermoplastic polyurethane composition of claim 1, wherein the polyester polyol has a number average molecular weight of less than 5,000 Da.

3. 3. The thermoplastic polyurethane composition according to claim 1 or 2, wherein the polyester polyol has a number average molecular weight in the range of 800 to 5,000 Da, preferably 1,000 to 3,000 Da.

4. 4. The thermoplastic polyurethane composition of any one of claims 1 to 3, wherein the diisocyanate is in an amount to provide an NCO:OH molar ratio of 1:1.25 to 1.25:

1.

5. The thermoplastic polyurethane composition of any one of claims 1 to 4, wherein the molar ratio of chain extender to polyol is from 1:1 to 1:

9.

6. The thermoplastic polyurethane composition according to any one of claims 1 to 5, wherein the molar ratio of 2,5-furandicarboxylic acid to short-chain diol in the polyester polyol (a) is from 1:1 to 1:5, or from 1:1 to 1:2, or from 1:1 to 1:1.5, or from 1:1 to 1:1.

25.

7. 7. The thermoplastic polyurethane composition of any one of claims 1 to 6, wherein the short chain diol is selected from the group consisting of 1,4-butanediol (BDO) and 1,6-hexanediol (HDO), 1,3-propanediol (PDO), or mixtures thereof.

8. The thermoplastic polyurethane composition of any one of claims 1 to 7, wherein the chain extender component comprises or consists of 1,4-butanediol.

9. The thermoplastic polyurethane composition of any one of claims 1 to 7, wherein the chain extender component comprises or consists of 1,3-propanediol (PDO).

10. 10. The thermoplastic polyurethane composition of any one of claims 1 to 9, wherein the diisocyanate component is selected from diphenyl diisocyanate (MDI), hexamethylene diisocyanate (HDI), or mixtures thereof.

11. The thermoplastic polyurethane composition of any one of claims 1 to 10, wherein the diisocyanate component comprises or consists of MDI.

12. 12. The thermoplastic polyurethane composition of any one of claims 1 to 11, wherein the diisocyanate component comprises or consists of HDI.

13. 13. The thermoplastic polyurethane composition of any one of claims 1 to 12, wherein the thermoplastic polyurethane has a hard segment content of 2 to 50 wt% or 7 to 36 wt%.

14. 14. The thermoplastic polyurethane composition of any one of claims 1 to 13, wherein the thermoplastic polyurethane exhibits a Shore D hardness, determined according to ISO 7619-1:2010, of at least 60, or at least 70, or at least 80, or at least 86, or at least 90.

15. A thermoplastic polyurethane composition according to any one of the preceding claims, wherein the thermoplastic polyurethane exhibits a recovery stress of 1 to 30 MPa, preferably 14 to 30 MPa.

16. The thermoplastic polyurethane has a viscosity of 0.6 to 30 MJ / m ３ or 8 to 30 MJ / m ３ The thermoplastic polyurethane composition of any one of claims 1 to 15, exhibiting an energy output of

17. A molded article comprising the thermoplastic polyurethane composition of any one of claims 1 to 16.

18. 20. The molded article of claim 17, wherein the moldable article is a medical device.

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