Thermoplastic polyurethane composition with shape memory properties

Abstract

A thermoplastic polyurethane composition having shape memory properties, the thermoplastic polyurethane composition comprising the reaction product of a polyester polyol component comprising a short chain diol and a dicarboxylic acid, such as a 2, 5-furandicarboxylic acid, a diisocyanate component, and a chain extender component.

Description

Technical Field

[0001] The present invention relates to thermoplastic polyurethane (TPU) compositions having excellent shape memory and thermomechanical properties, which compositions are useful in molded articles. Background Art

[0002] Thermoplastic polyurethane (TPU) is an excellent choice of material for many applications due to its easy processing and excellent properties, including resistance to abrasion, impact and chemical agents, high flexibility and cuttability, good environmental weatherability and biocompatibility.

[0003] As is well known, TPU is prepared by reacting a diisocyanate compound, a polymeric diol, and a difunctional chain extender. Typically, a large amount of diisocyanate and chain extender is required to obtain a high hardness product with maintained mechanical properties of the material. However, due to the high toxicity and environmental impact of diisocyanates, the high hardness material presents a high environmental footprint. Therefore, the development of a high hardness material with a limited amount of hazardous diisocyanates is of particular interest for the manufacture of a more environmentally friendly TPU.

[0004] The development of thermally induced shape memory polymers (SMPs) has gained attention due to their increased interesting properties such as recovery stress and energy output. These materials can switch from plastic deformation behavior to elastic behavior when triggered by external stimuli such as heat, light or electricity. When the switch in deformation behavior occurs, the SMP performs mechanical work. In particular, thermally activated SPMs, i.e., when the glass transition temperature (T g ) or melting transition temperature (T m ) can be used for many applications in different fields, such as in medical implants or devices, smart actuators or self-deployed structures.

[0005] Shape memory polymers and molded articles are disclosed in, for example, US2008221279A1 and US10907006B2.

[0006] However, there remains a general need in the current state of the art for SMPs with lower toxicity, high recovery stress and energy output.The present invention addresses some or all of the needs identified above, and addresses some or all of the problems identified above. Summary of the invention

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

[0008] In one aspect, the present invention is directed to a thermoplastic polyurethane composition comprising the reaction product of:

[0009] (a) A polyester polyol comprising a short-chain diol and a dicarboxylic acid selected from the group consisting of 2,5-furandicarboxylic acid.

[0010] (b) a diisocyanate component; and

[0011] (c) Chain extender component.

[0012] Thermoplastic polyurethane compositions are suitable for making molded articles having shape memory properties.

[0013] In another aspect, the present invention relates to a molded article comprising the thermoplastic polyurethane composition according to the first aspect.

[0014] The following implementations of the present subject matter are contemplated:

[0015] 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.

[0016] 2. The thermoplastic polyurethane composition according to embodiment 1, wherein the number average molecular weight of the polyester polyol is less than 5,000 Da.

[0017] 3. The thermoplastic polyurethane composition according to embodiment 1 or embodiment 2, wherein the number average molecular weight of the polyester polyol is in the range of 800 Da to 5,000 Da, preferably 1,000 Da to 3,000 Da.

[0018] 4. The thermoplastic polyurethane composition of any of embodiments 1 to 3, wherein the amount of the diisocyanate provides a NCO:OH molar ratio of 1:1.25 to 1.25:1.

[0019] 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.

[0020] 6. The thermoplastic polyurethane composition according to any one of embodiments 1 to 5, wherein the molar ratio of the 2,5-furandicarboxylic acid to the short-chain diol of 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.

[0021] 7. The thermoplastic polyurethane composition according to any one of embodiments 1 to 6, wherein the short chain diol is selected from the group consisting of: 1,4-butanediol (BDO)

[0022] and 1,6-hexanediol (HDO), 1,3-propylene glycol (PDO), or a mixture thereof.

[0023] 8. The thermoplastic polyurethane composition according to any one of embodiments 1 to 7, wherein the chain extender component comprises or consists of 1,4-butanediol.

[0024] 9. The thermoplastic polyurethane composition according to any one of embodiments 1 to 7, wherein the chain extender component comprises or consists of 1,3-propylene glycol (PDO), optionally wherein the diisocyanate component is selected from the group consisting of: aromatic diisocyanates and aliphatic diisocyanates or mixtures thereof.

[0025] 10. The thermoplastic polyurethane composition according to any one of embodiments 1 to 9, wherein the diisocyanate component is selected from diphenyl diisocyanate (MDI), hexamethylene diisocyanate (HDI), or a mixture thereof.

[0026] 11. The thermoplastic polyurethane composition according to any one of embodiments 1 to 10, wherein the diisocyanate component comprises or consists of MDI.

[0027] 12. The thermoplastic polyurethane composition according to any one of embodiments 1 to 11, wherein the diisocyanate component comprises or consists of HDI.

[0028] 13. The thermoplastic polyurethane composition according to any one of embodiments 1 to 12, wherein the thermoplastic polyurethane has a hard segment content of 2 wt% to 50 wt% or 7 wt% to 36 wt%.

[0029] 14. The thermoplastic polyurethane composition of any one of embodiments 1 to 13, wherein the thermoplastic polyurethane 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.

[0030] 15. The thermoplastic polyurethane composition according to any one of embodiments 1 to 14, wherein the thermoplastic polyurethane exhibits a recovery stress of 1 MPa to 30 MPa, preferably 14 MPa to 30 MPa.

[0031] 16. The thermoplastic polyurethane composition according to any one of embodiments 1 to 15, wherein the thermoplastic polyurethane exhibits a thermal conductivity of 0.6 MJ / m 3 Up to 30MJ / m 3 or 8MJ / m 3 Up to 30MJ / m 3 energy output.

[0032] 17. A molded article comprising the thermoplastic polyurethane composition according to any one of embodiments 1 to 16.

[0033] 18. The molded article according to embodiment 17, wherein the molded article is a medical device. DETAILED DESCRIPTION

[0034] Unless the context clearly dictates otherwise, the articles "a" and "an" are used herein to refer to one or more than one (i.e., at least one) of the grammatical object of the article. By way of example, "an element" means one element or more than one element.

[0035] Unless otherwise expressly indicated in the examples or otherwise, all numerical amounts in this specification specifying amounts of materials, 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 (such as the amount or weight of a particular component 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 numerical amounts in the specification specifying amounts or ratios of materials are based on weight.

[0036] As used herein, the terms "comprising" or "including" (which are inclusive or open-ended and do not exclude additional unrecited elements or method steps) are intended to encompass, as alternative embodiments, the phrases "consisting essentially of" and "consisting of," wherein "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 essence or basic and novel characteristics of the composition or method under consideration.

[0037] Temperature activated shape memory polymers are materials that can switch between a permanent shape and a pre-programmed temporary shape depending on their temperature. These materials can be deformed below their switching temperature and cooled to their temporary shape, which will be stored by the material until the temperature rises again and exceeds the switching temperature.

[0038] The present invention provides a shape memory TPU composition having desired hardness, recovery stress, energy output and temperature resilience.

[0039] Polyester polyol components

[0040] The polyester polyols contain short chain diols and 2,5-furandicarboxylic acid (FDCA).

[0041] FDCA is a member of the furan class carrying two carboxyl 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.

[0042] Suitable short-chain glycols include, for example, those having 2 to 12 carbon atoms. Suitable glycols may include, for example, ethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol (PDO), 1,3-butylene glycol, 1,4-butylene glycol, 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 glycol used in the present invention may be HDO, PDO, or a mixture thereof. In one embodiment, the short-chain glycol comprises HDO or even consists essentially of it. In one embodiment, the short-chain glycol comprises PDO or even consists essentially of it.

[0043] In one embodiment, the number average molecular weight (M) of the polyol component of the present invention, which may comprise a polyol as defined above, is n ) is from about 250Da to about 5,000Da, such as from about 1,000Da to about 3,000Da. When referred to herein, the M of the polyol n pass 1 H NMR end group analysis was determined by integration of the signals corresponding to the terminal CH2OH protons and the α-ester protons.

[0044] In one embodiment, the molar ratio of 2,5-furandicarboxylic acid to short chain diol of 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.

[0045] Diisocyanate component

[0046] The diisocyanate component of the present invention may be selected from any diisocyanate known to those skilled in the art. Useful diisocyanates may be selected from aromatic isocyanates, aliphatic isocyanates, or combinations thereof. Non-limiting examples of useful diisocyanates may include aromatic diisocyanates such as 4,4'-methylenebis(phenyl isocyanate) (MDI), 3,3'-dimethyl-4,4'-biphenylene diisocyanate (TODI), meta-xylene diisocyanate (XDI), 1,4-phenylene diisocyanate, 1,5-naphthalene diisocyanate (NDI) and toluene diisocyanate (TDI); and aliphatic diisocyanates such as isophorone diisocyanate (IPDI), 1,4-cyclohexyl diisocyanate (CHDI), 1,6-hexamethylene diisocyanate (HDI), 1,10-decamethylene diisocyanate, lysine diisocyanate (LDI), 1,4-butane diisocyanate (BDI) and 4,4'-dicyclohexylmethane diisocyanate (H12MDI). A mixture of two or more diisocyanates may be used. In particular, the diisocyanate may be MDI and / or HDI. More particularly, the diisocyanate component comprises or even consists essentially of MDI.In some embodiments, the diisocyanate component comprises or even consists essentially of HDI.

[0047] The thermoplastic polyurethane composition may 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.

[0048] In one embodiment, the thermoplastic polyurethane composition may include 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.

[0049] In another embodiment, the thermoplastic polyurethane composition may comprise or consist essentially 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 essentially 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.

[0050] In another embodiment, the thermoplastic polyurethane composition may comprise or consist essentially 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 essentially 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.

[0051] Chain Extender

[0052] Chain extenders are desirably employed in the polyurethane formulations of the present invention to increase the molecular weight of the polyurethane formulations. They are also responsible for the formation of crystalline hard blocks, resulting in thermoplastic polyurethanes having desirable mechanical properties.

[0053] Suitable chain extenders include relatively small polyols such as lower aliphatic or short chain diols having from 2 to 20, or from 2 to 12, or from 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-hexamethylene glycol (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 hydroxyethylresorcinol (HER), pentylspirodiol (PSG), hydroquinone bis(2-hydroxyethyl) ether hydroquinone (HQEE), dipropylene glycol (DPG), 2-methyl-1,3-propanediol, 2-butyl-2-ethyl-1,3-propanediol (BEPD), and the like, and mixtures thereof. In one embodiment, the chain extender comprises or even consists essentially of 1,4-butanediol (BDO).

[0054] The molar ratio of chain extender to polyol may be from 1:1 to 1:9.

[0055] The hard segment content of the thermoplastic polyurethane composition is defined as the total weight percent of the diisocyanate component and the chain extender component.

[0056] One of the advantages of the TPU compositions of the present invention is that they exhibit high hardness even at low hard segment concentrations.

[0057] Therefore, in some embodiments of the present invention, the hard segment content of the thermoplastic polyurethane herein may be 50 wt% or less. In particular, the hard segment content may be 2 wt% to 50 wt%, or 7 wt% to 36 wt%.

[0058] 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.

[0059] The thermoplastic polyurethane composition can have a Shore D hardness of at least 61 as determined by ISO 7619-1:2010 and a hard segment content of 7 to 36 wt%.

[0060] The thermoplastic polyurethane composition may have a molar ratio of chain extender to polyol of 1:1 to 1:9.

[0061] In one embodiment, the amount of diisocyanate provides a NCO:OH molar ratio of 1:1.25 to 1.25:1, specifically 1:1.1 to 1.1:1.

[0062] In some embodiments, the TPU composition of the present invention exhibits desirable elongation and strain properties. For example, when measured using dumbbell-shaped specimens prepared according to ISO 37 1A and using a process according to ISO 37 1A (modified to use a rate of 5 mm / min at 21° C.), the TPU composition may have an ultimate tensile strength of at least 28 MPa and a strain of at least 11%. The shape fixity (R f ) and recovery (R r ) property. Shape fixity refers to the percentage of elongation induced into a material after deformation to its temporary shape while maintained at 20°C below the material's transition temperature under no load, and is calculated as follows:

[0063]

[0064] where ε f (n) is the strain of the system once the stress is released after elongation at 20°C below the transition temperature, and ε m is the maximum strain applied to the system. Shape recovery refers to the percentage of the initial shape before deformation that the material recovers under no load once it is heated to 20°C above the transformation temperature of the material after being deformed into a temporary shape, and the percentage is calculated as follows:

[0065]

[0066] where ε f(n) is the strain in the system after elongation at 20°C below the transition temperature once the stress has been released, ε m is the maximum strain applied to the system, ε r (n) is the strain of the sample in the stress-free state at 20°C above the transition temperature after a 30-minute recovery time, and ε0 is the strain of the sample at the beginning of the cycle. Shape fixity and shape recovery can be measured by a process involving the following steps: (1) setting the temperature above the T of the material g 20℃; (2) isothermally maintained for 5 minutes; (3) strain increased to 100% at a rate of 50% / min; (4) isothermally maintained for 5 minutes; (5) temperature decreased to below T at a rate of -10℃ / min g 20℃; (6) isothermally maintained for 5 minutes; (7) setting the force to 0.001N; (8) isothermally maintained for 5 minutes; (9) raising the temperature to a temperature higher than the T of the material at a rate of 10℃ / min g 20°C; (10) isothermal for 30 minutes. Steps 3 to 10 are repeated twice to complete three cycles to report the results. The device for measuring shape fixity and shape recovery can be measured with any known suitable instrument, such as DMA Q800 from TA Instruments.

[0067] 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 it is transformed from a temporary shape to a permanent shape. It has been observed that the TPU compositions disclosed herein exhibit recovery stress and energy output.

[0068] The TPU composition as disclosed herein may have a recovery stress of 1 MPa to 30 MPa, specifically 14 MPa to 30 MPa.

[0069] Based on the detailed examples, a person skilled in the art can routinely repeat the measurement to objectively determine the recovery stress of the TPU composition.

[0070] For example, to measure the recovery stress of a TPU composition, an ISO 37 1A dumbbell specimen was used at a temperature above the glass transition temperature (T g )20℃ recovery stress. This value corresponds to the value when the material has been above T g The stress of the material when stretched to 90% of its ultimate strain at 20°C and then allowed to relax at a fixed elongation for 5 minutes. g It can be measured using a method following ISO 11357-2. As used in the present invention, ISO 11357-2 is used, but T is measured using a heating and cooling rate of 10°C / min. g .

[0071] The energy output (volume energy density) of the TPU composition disclosed herein can be 0.6 MJ / m 3 Up to 30MJ / m 3 , especially 8MJ / m 3 Up to 30MJ / m 3 , more particularly 20MJ / m 3 Up to 30MJ / m 3 .

[0072] Based on the detailed examples, a person skilled in the art will be able to routinely repeat the measurements to objectively determine the energy output of the TPU composition.

[0073] 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 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]:

[0074]

[0075] The TPU composition of the present invention is formed by reacting a polyester polyol component and a hard segment component comprising a diisocyanate and a chain extender, and optionally a catalyst.

[0076] The three reactants (polyol polyester, diisocyanate and chain extender) are reacted together to form the TPU of the present invention. Any known process for reacting these three reactants can be used to make the TPU.

[0077] The method may be a so-called "one-step" process, where all three reactants are added to the extruder reactor and reacted. The reaction may include melting the polyol at 140°C to 180°C, and adding the diisocyanate and chain extender and optionally a catalyst and / or additives.

[0078] Thus, in one embodiment, the process includes melting the polyester polyol at a temperature of 140° C. to 180° C. to melt the polyester polyol, and adding a diisocyanate and a chain extender. The process may further include adding a catalyst and / or an additive.

[0079] The TPU can also be prepared using a prepolymer process. In the prepolymer approach, the polyol intermediate is usually reacted with an equivalent excess of one or more diisocyanates to form a prepolymer solution with free or unreacted diisocyanates therein. The reaction is usually carried out at a temperature of about 80°C to about 220°C, or about 150°C to about 200°C, optionally in the presence of a suitable urethane catalyst. Subsequently, a chain extender as indicated above is added in an equivalent amount generally equal to the isocyanate end groups and any free or unreacted diisocyanate compounds. The chain extension reaction temperature is generally about 180°C to about 250°C or about 200°C to about 240°C. Generally, the prepolymer approach can be carried out in any conventional device including an extruder. In such embodiments, the polyol intermediate is reacted with an equivalent excess of diisocyanates in the first part of the extruder to form a prepolymer solution, and then a chain extender is added at the downstream portion and reacted with the prepolymer solution. Any conventional extruder may 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.

[0080] Auxiliary substances and catalysts

[0081] Optionally, catalysts, auxiliary substances and / or additives may be used in the polyurethane reaction mixture of the invention.

[0082] Any catalyst conventionally employed or known in the art for catalyzing the reaction of isocyanates with reactive hydrogen-containing compounds can be used for this purpose. Examples of suitable catalysts which promote the reaction between the NCO groups of diisocyanates and the hydroxyl groups of polyols and chain extenders are, in particular, 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 titanates, iron compounds (e.g. iron acetylacetonate), bismuth compounds (e.g. bismuth octoate, bismuth neodecanoate, bismuth laurate), tin compounds (e.g. stannous diacetate, stannous dioctoate, stannous dilaurate) or dialkyltin salts of aliphatic carboxylic acids (e.g. dibutyltin diacetate, dibutyltin dilaurate, etc.), phenylmercuric propionate, lead octoate, iron acetylacetonate, magnesium acetylacetonate, etc. Mixtures of the abovementioned catalysts can likewise be used.

[0083] 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 ester amides and silicone compounds, anti-caking agents, inhibitors, stabilizers against hydrolysis, light, heat and discoloration, flame retardants, flame retardants, dyes, pigments, inorganic and / or organic fillers and reinforcing agents.

[0084] application

[0085] The above-mentioned thermoplastic polyurethane (TPU) compositions are very useful materials that can provide an attractive combination of physical properties, especially mechanical properties and shape memory properties.

[0086] The compositions of the present invention and any blends thereof can be used in a variety of applications. Non-limiting examples of articles comprising the TPU compositions of the present invention may include cooking and storage vessels, articles such as furniture, automotive parts, toys, sportswear, medical devices, glasses (including eyeglass frames and temple pieces), sterilizable medical devices, sterilization containers, fibers, woven fabrics, nonwoven fabrics, curtains, gowns, filters, sanitary products, diapers and films, oriented films, sheets, tubes, pipes, wire sheaths, cable sheaths, agricultural films, geomembranes, sports equipment, cast films, blown films, boats and watercraft parts, and other such articles. These compositions may be suitable for automotive parts such as bumpers, grills, trims, control panels and instrument panels, exterior doors and cover parts, spoilers, windshields, windshield wipers, hub caps, rearview mirror housings, body panels, protective side moldings, and interior and exterior parts associated with cars, trucks, boats and other vehicles.

[0087] Other useful articles can be formed from the compositions of the present invention, including: crates, containers, packages, laboratory equipment, such as roller bottles and media bottles for culture growth, office floor mats, instrument sample racks and sample windows; liquid storage containers such as bags, pouches and bottles for storage of blood or solutions and IV infusion; packaging materials, including those for any medical device or drug (including unit dose or other blister or foam packaging) and for wrapping or containing food preserved by radiation. Other useful items include medical tubing and valves for any medical device including infusion kits, catheters and respiratory treatments; and packaging materials for medical devices or irradiated foods, including trays and storage liquids, especially water, milk or juice; including unit serving containers and bulk storage containers, and conveying devices such as tubes, hoses, and tubing, including their liners and / or jackets.

[0088] In the medical field, sutures can be produced with a shape memory switching temperature at about body temperature. These sutures will tighten when body temperature is reached, thereby tightening the suture without the need for surgeon 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 temperature. This allows for easier insertion of the stent and minimizes the damage caused when the device is introduced.

[0089] It is also possible to create lightweight, self-deployable structures for use in smart buildings (such as in adaptive awnings) or in aerospace applications (such as solar sails).

[0090] These articles can be made or prepared by any useful process for forming thermoplastic polyurethane materials. This will include at least molding, including compression molding, injection molding, blow molding and transfer molding; film blowing or casting; extrusion and thermoforming; and by lamination, pultrusion, stretch reduction, rotational molding, spin-bonding, melt spinning, melt blowing; fiber spinning, electrospinning or a combination thereof. The use of at least thermoforming or film applications allows the possibility and derivation of benefits from uniaxial or biaxial orientation of the material.

[0091] The present invention will be better understood by reference to the following examples, which are intended to illustrate the present invention but not to limit the present invention.

[0092] Example

[0093] abbreviation

[0094] The following abbreviations are used in the examples: MDI=4,4′-methylenebis(phenylisocyanate) and HDI=1,6-hexamethylene diisocyanate.

[0095] Synthesis of Thermoplastic Polyurethane

[0096] As disclosed in Table 1, a series of different thermoplastic polyurethanes were synthesized using 1,4-butanediol as a chain extender. The NCO:OH ratio was 1:1. The Shore D hardness and glass transition temperature (T) of the materials of the examples were determined according to the following method: g ):

[0097] -Hardness calculated according to ISO 7619-1:2010

[0098] The glass transition temperature is determined on DSC as the T of the second cooling and heating g The data were acquired using a heating / cooling rate of 10°C / min.

[0099] The measured hardness and T g The values ​​are included in Table 1.

[0100] Table 1: TPU composition and physical properties

[0101]

[0102]

[0103]

[0104] 1

[0105] As a general trend, the hardness of TPUs with similar hard segment content for FDCA is higher than that of standard TPUs with aliphatic polyols (i.e., ADPBDO), and even higher than TPUs made with other aromatic polyols (such as IPHTA). The same trend is observed for glass transition temperature.

[0106] Recovery stress / energy output / rebound resilience measurement

[0107] For each of the Example TPU compositions, the recovered stress, energy output, and rebound temperature were measured.

[0108] As described herein, DMA Q800 from TA Instruments was used on ISO37 1A dumbbell samples at temperatures above the T of each material. g The recovery stress and energy output were measured at 20°C. 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 relaxed for 5 minutes at a fixed elongation, and the stress value after relaxation was selected as the recovery stress of the material.

[0109] 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. Central Science 2021, 7(10), 1657–1667. https: / / doi.org / 10.1021 / acscentsci.1c00829]:

[0110]

[0111] The temperature resilience among the mechanical properties of TPU compositions has been studied by dynamic mechanical analysis. This resilience is important because the higher the resilience, the higher the maximum use temperature of the material will be. Therefore, if these materials are to be used in applications that require the material to withstand high temperatures, high temperature resilience is required. In order to assess the trend of these temperature resilience, dynamic mechanical analysis (DMA) has been used. This is carried out in the following manner: using the ASTM D4045-06 test, which is modified to heat the material from -50°C at a rate of 5°C / min with a frequency of 1 Hz and an amplitude of 10 μm on a double cantilever fixture on a 35 mm×15 mm×2.5 mm to 3 mm sample; and determining the temperature at which the material reaches a storage modulus of 5 MPa.

[0112] The results of the recovery stress, energy output and rebound resilience measurements are listed in Table 2.

[0113] Table 3: Energy output and recovery stress for each sample in the sample

[0114]

[0115]

[0116] For TPUs with similar compositions, the recovery stress and energy output of those polymers containing FDCA are higher. In addition, the temperature resilience of FDCA TPU is higher than that of IPHTA TPU.

[0117] The present invention has been explained with respect to its preferred embodiments, but it should be understood that various modifications thereof will become apparent to those skilled in the art upon reading this specification. Therefore, it should be understood that the invention disclosed herein is intended to cover these modifications that fall within the scope of the appended claims.

Claims

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) Chain extender component.

2. The thermoplastic polyurethane composition according to claim 1, wherein the number average molecular weight of the polyester polyol is less than 5,000 Da.

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

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

1.

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

9.

6. The thermoplastic polyurethane composition according to any one of claims 1 to 5, wherein the molar ratio of the 2,5-furandicarboxylic acid to the short-chain diol of 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 according to 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-propylene glycol (PDO), or a mixture thereof.

8. The thermoplastic polyurethane composition according to 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-propylene glycol (PDO).

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

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

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

13. The thermoplastic polyurethane composition according to 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. The thermoplastic polyurethane composition of any one of claims 1 to 13, wherein the thermoplastic polyurethane 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.

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

16. The thermoplastic polyurethane composition according to any one of claims 1 to 15, wherein the thermoplastic polyurethane exhibits a thermal conductivity of 0.6 MJ / m 3 Up to 30MJ / m 3 or 8MJ / m 3 Up to 30MJ / m 3 energy output.

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

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

Images