Non-softening thermoplastic polyurethanes

Abstract

The non-softening thermoplastic polyurethane (TPU) compositions described herein have good rebound elasticity while maintaining a good combination of other properties including hardness, low temperature flexibility, wear resistance, weather resistance, low density, and combinations thereof. The softening degree is irrelevant to the hardness of the TPU in the technology disclosed by the invention. This combination of properties enables TPU compositions described herein to be useful for materials in which polyamide copolymer (COPA) and / or polyether block amide (PEBA) materials are traditionally more commonly used than TPU.

Description

Technical Field

[0001] In one aspect, the technology of the present invention relates to thermoplastic polyurethane (TPU) compositions having non-softening and wet flexibility properties. Such a combination of properties makes the TPU compositions described herein useful as materials for applications where polyamide copolymers (COPA) and / or polyether block amides (PEBA) materials are more commonly used than TPU, particularly as materials in medical applications where physical properties, chemical stability, and compatibility in the in vivo environment are important. Background Art

[0002] Thermoplastic polymers, copolymers and polymer blends have been widely used in the manufacture of medical devices, including extensive long-term and short-term implant devices. Many polymers and polymer blends used in medical devices have specific physical and chemical properties, which make them particularly suitable for in vivo applications. Preferred chemical, physical and thermomechanical properties depend on specific functions, the type of tissue, cell or fluid contacting the medical device and acceptable or desired manufacturing processes. The major considerations for selecting the polymer for medical devices include the chemical stability (particularly hydrolytic stability) of the polymer, the toxicity of the polymer and the degree of interaction between tissue or blood and the polymer. In addition, polymers or polymer blends should meet all physical requirements related to the function of the medical device, including intensity, consistency, rigidity, flexibility and resilience.

[0003] Certain medical devices, such as catheters, represent a particularly large class of medical devices used in a variety of in vivo applications. Typically, the catheter body is formed from one type of polymer, but more than one type may be incorporated into the catheter body to provide a device that meets the physical and chemical requirements of the catheter. Specific types of catheters are widely used in a variety of procedures and are physically designed to be manipulated through tortuous fluid pathways within the body to a pre-selected site.

[0004] In order to safely maneuver the catheter into position, the material used to manufacture the device should have sufficient flexibility and sufficient bending stiffness to avoid perforating or otherwise damaging body tissue. On the other hand, excessive softness or flexibility of the catheter material can make it difficult to maneuver the catheter through the fluid pathway after insertion. The material should have a combination of mechanical properties to allow the device to bend and flex through the body's fluid pathway without causing damage.

[0005] Although thermoplastic polyurethanes have many mechanical properties that make them attractive for the manufacture of medical devices, it is known that TPU compositions with aromatic or cyclic aliphatic isocyanates in the hard segment generally exhibit softening when subjected to the aqueous environment present in the body, and are therefore not good candidates for certain applications that require maintaining sufficient hardness, flexibility, and maneuverability in these environments. Therefore, for such applications, COPA and / or PEBA materials are generally more commonly used than TPU.

[0006] Therefore, there is a continuing need for non-softening TPU compositions that can deliver high stiffness, elasticity, rebound elasticity, and flexibility, or any combination thereof, for in vivo implantation into a mammalian body environment. Summary of the invention

[0007] According to one aspect of the disclosed technology, a non-softened thermoplastic polyurethane (TPU) composition is provided that exhibits good mechanical properties, such as flexibility, maneuverability, and stiffness, which are at least comparable to PEBA and COPA materials.

[0008] In one aspect, the technology disclosed in the present invention provides a thermoplastic polyurethane (TPU) composition prepared from a reaction mixture, the reaction mixture comprising:

[0009] (a) at least one isocyanate-terminated low free polyurethane prepolymer (referred to as "prepolymer" for simplicity) composition prepared by the reaction of at least one polyisocyanate component (i) and at least one polyol component (ii), wherein the low free polyurethane prepolymer composition contains more than about 0 wt % to about 1 wt % or less, or about 0.05 wt % or less to about 0.75 wt % or less, or about 0.1 wt % or less to about 0.5 wt % or less of residual polyisocyanate component;

[0010] (b) at least one linear aliphatic polyisocyanate, wherein the weight ratio of the at least one aliphatic polyisocyanate to the low free polyurethane prepolymer ranges from about 10:1 to about 1:10;

[0011] (c) at least one optional polyol component ranging from 0 weight percent to about 80 weight percent based on the total weight of the thermoplastic polyurethane; and

[0012] (d) a chain extender component comprising (iii) a first chain extender selected from at least one linear unsubstituted alkane diol containing from about 2 to about 20 carbon atoms, and (iv) a second chain extender selected from at least one cycloaliphatic diol or at least one aliphatic branched short chain diol or at least one dianhydrohexitol diol, wherein the weight ratio of the first chain extender to the second chain extender ranges from about 1:19 to about 19:1.

[0013] In one aspect, the technology disclosed in the present invention provides a thermoplastic polyurethane composition prepared from a reaction mixture, the reaction mixture comprising:

[0014] (a) at least one isocyanate-terminated low-free polyurethane prepolymer (referred to as "prepolymer" for simplicity) composition, which is composed of at least one aliphatic diisocyanate component (i)

[0015] and at least one polyether polyol component (ii), wherein the low free polyurethane prepolymer composition comprises a residual polyisocyanate component in an amount exceeding about 0 wt % to about 1 wt % or less, or about 0.05 wt % or less to about 0.75 wt % or less, or about 0.1 wt % or less to about 0.5 wt % or less;

[0016] (b) at least one linear aliphatic polyisocyanate, wherein the weight ratio of the at least one linear aliphatic polyisocyanate to the low free polyurethane prepolymer ranges from about 10:1 to about 1:10;

[0017] (c) at least one optional polyol component ranging from 0 weight percent to about 80 weight percent based on the total weight of the thermoplastic polyurethane; and

[0018] (d) a chain extender component comprising (iii) a first chain extender selected from at least one linear unsubstituted alkane diol having from about 2 to about 20 carbon atoms, and (iv) a second chain extender selected from at least one cycloaliphatic diol, wherein the weight ratio of the first chain extender to the second chain extender ranges from about 1:19 to about 19:1.

[0019] In one aspect, the technology disclosed in the present invention provides a thermoplastic polyurethane composition prepared from a reaction mixture, the reaction mixture comprising:

[0020] (a) at least one isocyanate-terminated low-free polyurethane prepolymer composition, which is obtained by

[0021] (i) 1,6-hexamethylene diisocyanate and (ii) polytetramethylene ether glycol (PTMEG), wherein the low free polyurethane prepolymer composition comprises a residual polyisocyanate component in an amount of more than about 0 wt % to about 1 wt % or less, or about 0.05 wt % or less to about 0.75 wt % or less, or about 0.1 wt % or less to about 0.5 wt % or less;

[0022] (b) at least one linear aliphatic polyisocyanate selected from 1,6-hexamethylene diisocyanate, wherein the weight ratio of the 1,6-hexamethylene diisocyanate to the low free polyurethane prepolymer ranges from about 10:1 to about 1:10;

[0023] (c) at least one optional polyol component ranging from 0 weight percent to about 80 weight percent based on the total weight of the thermoplastic polyurethane; and

[0024] (d) a chain extender component comprising (iii) a first chain extender comprising 1,4-butanediol, and (iv) a second chain extender comprising 1,4-cyclohexanedimethanol, wherein a weight ratio of the first chain extender to the second chain extender ranges from about 1:19 to about 19:1.

[0025] In one aspect, the non-softened TPU compositions of the disclosed technology can be used as materials for applications where polyamide copolymers (COPA) and / or polyether block amide (PEBA) materials have traditionally been used, particularly as materials in medical applications where physical properties, chemical stability, and compatibility in the in vivo environment are important.

[0026] In one aspect, the technology disclosed herein provides a non-softened TPU composition having one or more of the following properties:

[0027] a) a Shore D hardness of about 20 to about 75 as measured by ASTM D2240;

[0028] b) a dry flexural modulus of about 4,000 psi to about 90,000 psi as measured by ASTM D790;

[0029] c) a wet flexural modulus of about 3,000 psi to about 50,000 psi as measured by ASTM D790;

[0030] d) an elongation at break of about 300% to about 750% as measured by ASTM D412;

[0031] e) a tensile strength of about 5,000 psi to about 10,000 psi as measured by ASTM D412; and

[0032] f) a springback recovery of about 40% to about 65% as measured by ASTM D2632.

[0033] In one aspect, the TPU compositions of the presently disclosed technology provide 20% softening or less while maintaining enhanced dry flexural modulus, wet flexural modulus, tensile strength, and / or rebound resilience at comparable Shore D hardness values.

[0034] In one aspect, the TPU composition of the technology disclosed in the present invention further comprises: pigments, UV stabilizers, UV absorbers, antioxidants, lubricants, heat stabilizers, hydrolysis stabilizers, crosslinking activators, flame retardants, layered silicates, fillers, colorants, reinforcing agents, adhesion regulators, impact strength modifiers, radiopaque agents, antimicrobial agents, and mixtures thereof.

[0035] In one aspect, the non-softened TPU composition of the presently disclosed technology is suitable for making medical articles suitable for in vivo implantation into a mammalian body.

[0036] In one aspect, non-limiting examples of medical articles made from the TPU compositions of the presently disclosed technology include: pacemaker tips, angiographic catheters, angioplasty catheters, epidural catheters, thermodilution catheters, urological catheters, catheter connectors, medical tubing, cartilage replacements, or joint replacements.

[0037] The technology disclosed in the present invention also provides a method for preparing the non-softened thermoplastic polyurethane composition disclosed herein, the method comprising the following steps: (I) reacting a mixture comprising the following components:

[0038] (a) at least one isocyanate-terminated low free polyurethane prepolymer composition prepared by the reaction of at least one polyisocyanate component (i) and at least one polyol component (ii), wherein the low free polyurethane prepolymer composition comprises from greater than about 0 wt % to about 1 wt % residual polyisocyanate component;

[0039] (b) at least one linear aliphatic polyisocyanate, wherein the weight ratio of the at least one aliphatic polyisocyanate to the low free polyurethane prepolymer ranges from about 10:1 to about 1:10;

[0040] (c) at least one polyol component ranging from 0 wt % to about 80 wt % of the total weight of the thermoplastic polyurethane; and

[0041] (d) a chain extender component comprising (iii) a first chain extender selected from at least one linear unsubstituted alkane diol containing from about 2 to about 20 carbon atoms, and (iv) a second chain extender selected from at least one cycloaliphatic diol or at least one aliphatic branched short chain diol or at least one dianhydrohexitol diol, wherein the weight ratio of the first chain extender to the second chain extender ranges from about 1:19 to about 19:1.

[0042] The technology disclosed in the present invention also provides a method, which further includes the following steps: (II) mixing the non-softened thermoplastic polyurethane composition prepared in step (I) with one or more additional additives, wherein the additional additives are selected from: pigments, ultraviolet stabilizers, ultraviolet absorbers, antioxidants, lubricants, heat stabilizers, hydrolysis stabilizers, crosslinking activators, flame retardants, layered silicates, fillers, colorants, reinforcing agents, adhesion regulators, impact strength modifiers, radiopaque agents, antimicrobial agents and mixtures thereof. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] Figure 1 Graph showing Shore D Durometer value (x-axis) versus percent softening (y-axis) for selected TPU compositions of the presently disclosed technology.

[0044] Figure 2 Graph showing Shore D Durometer hardness values ​​(x-axis) versus percent softening (y-axis) for select TPU compositions of the presently disclosed technology relative to a benchmark polymer and comparative TPU samples. DETAILED DESCRIPTION

[0045] Various aspects, features, and embodiments of the presently disclosed technology are described below by way of non-limiting illustration.

[0046] The non-softened TPU compositions of the presently disclosed technology may suitably comprise, consist of, or consist essentially of the components, elements, and process descriptions described herein. The technology exemplarily disclosed herein may suitably be practiced in the absence of any element not specifically disclosed herein.

[0047] Unless otherwise indicated, in all aspects of the technology disclosed in the present invention, all percentages are calculated by weight of the total composition. All ratios are expressed as weight ratios. Unless otherwise indicated, all numerical ranges of amounts are inclusive and combinable.

[0048] Although overlapping weight ranges of various components and ingredients that may be included in the disclosed compositions have been expressed for selected embodiments and aspects of the disclosed technology, the amount of each component in the disclosed compositions is selected from its disclosed range so that the sum of all components or ingredients in the composition will total 100 weight %. The amount employed will vary with the purpose and characteristics of the desired product and can be readily determined by those skilled in the art.

[0049] The term "non-softening" (expressed as % softening) means that the TPU composition of the presently disclosed technology resists softening over time when exposed to an in vivo environment. % softening is calculated by the following formula (see methods in Examples 7 to 12):

[0050] Softening % = [(flexural modulus 干 -Flexural modulus 湿 )×100 / flexural modulus 干

[0051] "Low free" means that the polyurethane prepolymer (a) of the presently disclosed technology contains more than about 0 wt % to about 1 wt % or less, or about 0.05 wt % or less to about 0.75 wt % or less, or about 0.1 wt % or less to about 0.5 wt % or less of unreacted (residual) polyisocyanate used to prepare the prepolymer.

[0052] The technology disclosed in the present invention provides a thermoplastic polyurethane (TPU) composition prepared from a reaction mixture, the reaction mixture comprising:

[0053] (a) at least one isocyanate-terminated low free polyurethane prepolymer composition prepared by the reaction of at least one polyisocyanate component (i) and at least one polyol component (ii), wherein the low free polyurethane prepolymer composition comprises a residual polyisocyanate (e.g., diisocyanate) component in an amount ranging from about 1 wt % to about 80 wt %, or from about 15 wt % to about 50 wt %, based on the total weight of the low free polyurethane prepolymer;

[0054] (b) at least one linear aliphatic polyisocyanate, wherein the weight ratio of the at least one aliphatic polyisocyanate to the low free polyurethane prepolymer ranges from about 10:1 to about 1:10, or from about 1:1 to about 1:2;

[0055] (c) at least one polyol component ranging from 0 weight percent, or from about 5 weight percent to about 80 weight percent of the total weight of the thermoplastic polyurethane; and

[0056] (d) a chain extender component comprising (iii) a first chain extender selected from at least one linear unsubstituted alkane diol containing from about 2 to about 20 carbon atoms, and (iv) a second chain extender selected from at least one cycloaliphatic diol or at least one aliphatic branched short chain diol or at least one dianhydrohexitol diol, wherein the weight ratio of the first chain extender to the second chain extender ranges from about 1:19 to about 19:1, or from about 1:1 to about 10:1, or from about 2:1 to about 5:1.

[0057] Isocyanate-terminated low-free polyurethane prepolymer (component (a))

[0058] At least one isocyanate-terminated low-free polyurethane prepolymer composition (polyurethane prepolymer) used to prepare the non-softened TPU composition of the technology disclosed in the present invention is prepared by reacting at least one polyisocyanate component (i) and at least one polyol component (ii) containing at least two hydroxyl groups in a stoichiometric excess.

[0059] In one aspect, the at least one isocyanate terminated low free polyurethane prepolymer composition is the reaction product of a stoichiometric excess of a diisocyanate component and a diol component.

[0060] The polyurethane prepolymer reaction product comprises oligomers and so-called "perfect" prepolymers. The desired high oligomer content of the prepolymer composition is greater than 20% by weight, or conversely, it can be expressed as a content of a 2:1 stoichiometric adduct of a diisocyanate and a polyol, which should be less than 75% by weight based on the total weight of the prepolymer composition. 2:1 stoichiometric adducts of diisocyanates and at least one polyol (“perfect prepolymers”) and processes for their preparation are widely known and described in the art, for example, in EP 0 288 823 A1, EP 0 370 408 A1, EP 0 370 392 A1, EP 0 827 995 A1, EP 1 237 967 A1, EP 1 237 971 A1, EP 1 249 460 A1, EP 1 253 159 A1, EP 1 499 653 A1 and EP 1 553 118 A1, which are hereby incorporated by reference.

[0061] The 2:1 stoichiometric adduct of a diisocyanate and at least one polyol of the disclosed technology is a stoichiometric end-capped product of one polyol molecule (B) and two diisocyanate molecules (A). In the case of a diol (difunctional polyol (B)), the stoichiometric ratio of diisocyanate to polyol in the reaction product is 2:1. A perfect prepolymer is essentially an adduct containing only one molecule of polyol (B) in each prepolymer molecule A:B:A (or A2B).

[0062] For difunctional polyols (B), the oligomers of prepolymer composition (a) are any species having a composition greater than the ideal 2:1 molecular ratio (A:B:A, i.e., diurethane), such as 3:2 (A:B:A:B:A, i.e., triurethane) or 4:3 (A:B:A:B:A:B:A, i.e., tetraurethane).

[0063] In one aspect, the prepolymer composition (1) comprises less than 75 wt%, or less than 73 wt%, or less than 70 wt% of a 2:1 stoichiometric adduct of a diisocyanate and a polyol, based on the total weight of the polyurethane prepolymer, and (2) comprises more than 0 wt% and less than 1.0 wt% of unreacted and thus free diisocyanate monomers. In one aspect, the technology disclosed in the present invention requires that the diisocyanate prepolymer reaction product (1) comprises more than 30 wt% of a 2:1 stoichiometric adduct of a diisocyanate and at least one polyol, and less than 75 wt%, or less than 73 wt%, or less than 70 wt% of a 2:1 stoichiometric adduct of a diisocyanate and at least one polyol, and (2) comprises more than 0 wt% and less than 0.1 wt% of unreacted diisocyanate monomers.

[0064] In one aspect, the polyurethane prepolymer reaction product comprises free prepolymer NCO functionality ranging from 0.2 wt % to 15 wt %, or from about 0.5 wt % to about 8 wt %, or from about 5 wt % to about 7 wt %. The free NCO content is usually determined according to ASTM D1638-70, by weight percentage. In one aspect, the polyurethane prepolymer composition of the technology disclosed in the present invention comprises free prepolymer NCO groups ranging from about 0.2 wt % to about 15 wt %, or from about 0.5 wt % to about 8 wt %, or from about 5 wt % to about 7 wt %, based on the weight of the polyurethane prepolymer, and unreacted (residual) diisocyanate monomers exceeding 0 wt % to less than 1.0 wt %. In one aspect, unreacted (residual) diisocyanate monomers are less than about 0.5 wt % or less than about 0.1 wt %, based on the weight of the polyurethane prepolymer.

[0065] In one aspect of the technology disclosed herein, the polyurethane prepolymer comprises at least about 30 wt% of a 2:1 stoichiometric adduct of a diisocyanate and at least one polyol and less than about 75 wt% of a 2:1 stoichiometric adduct of a diisocyanate and at least one polyol, or less than about 75 wt% of a 2:1 stoichiometric adduct of a diisocyanate and at least one polyol, or less than about 70 wt% of a 2:1 stoichiometric adduct of a diisocyanate and at least one polyol, or less than about 65 wt% of a 2:1 stoichiometric adduct of a diisocyanate and at least one polyol, or conversely, at least 20 wt% oligomers, preferably at least 25 wt% oligomers, more preferably at least 30 wt% oligomers, even more preferably at least 35 wt% oligomers, based on the total weight of the prepolymer.

[0066] Polyurethane prepolymer polyisocyanate (component (i))

[0067] The polyisocyanate component of the presently disclosed technology is not particularly limited and includes aromatic, aliphatic (cycloaliphatic and linear aliphatic) polyisocyanates and mixtures thereof. In one aspect, the polyisocyanate component used to prepare the prepolymer of the present technology is a diisocyanate. Non-limiting examples of suitable diisocyanates include: aromatic diisocyanates such as 4,4'-methylenebis-(phenyl isocyanate) (MDI); meta-xylene diisocyanate (XDI), phenylene-1,4-diisocyanate (PPDI), 3,3'-dimethyl-4,4'-biphenylene diisocyanate (TODI), diphenylmethane-3,3'-dimethoxy-4,4'-diisocyanate, toluene diisocyanate (TDI) and naphthalene-1,5-diisocyanate; cycloaliphatic diisocyanates such as isophorone diisocyanate (IPDI), dicyclohexylmethane-4,4'-diisocyanate (H12MDI), 1,4-cyclohexyl diisocyanate (CHDI), and linear aliphatic diisocyanates such as 1,6-hexamethylene diisocyanate (HDI) and decane-1,10-diisocyanate; and mixtures thereof.

[0068] Polyurethane prepolymer polyol (component (ii))

[0069] The polyurethane prepolymer described herein is prepared using a polyol component, which includes polyester polyols, polyether polyols, polycarbonate polyols, polysiloxane polyols, alkoxylated polysiloxane polyols, polybutadiene polyols, and combinations thereof.

[0070] In one aspect, the polyol is selected from hydroxyl terminated diols including one or more hydroxyl terminated polyesters, one or more hydroxyl terminated polyethers, one or more hydroxyl terminated polycarbonates, one or more hydroxyl terminated polysiloxanes, one or more hydroxyl terminated polybutadienes, and mixtures thereof.

[0071] Suitable hydroxyl terminated polyester intermediates include linear polyesters having a number average molecular weight (Mn) of about 500 to about 10,000, about 700 to about 5,000, or about 700 to about 4,000, and an acid number that is typically less than 1.3 or less than 0.5. The molecular weight is determined by measuring the terminal functional groups and is related to the number average molecular weight. The polyester intermediates can be generated by (1) esterification of one or more diols with one or more dicarboxylic acids or anhydrides or (2) transesterification, i.e., reaction of one or more diols with dicarboxylic acid esters. In one aspect, a molar ratio of more than one mole of diol to acid is used to obtain linear chains with a predominance of terminal hydroxyl groups. The dicarboxylic acids of the desired polyester can be aliphatic, alicyclic, aromatic, or a combination thereof. Suitable dicarboxylic acids, which may be used alone or in mixtures, generally have a total of 4 to 15 carbon atoms and include: succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, dodecanedioic acid, isophthalic acid, terephthalic acid, cyclohexanedicarboxylic acid, and the like. Anhydrides of the above dicarboxylic acids may also be used, such as phthalic anhydride, tetrahydrophthalic anhydride, and the like. Adipic acid is a preferred acid. The diols reacted to form the desired polyester intermediate may be aliphatic, aromatic, or a combination thereof, including any of the diols in the chain extender segment described above, and have a total of 2 to 20 or 2 to 12 carbon atoms. Suitable examples include ethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, 1,3-butanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 2,2-dimethyl-1,3-propanediol, 1,4-cyclohexanedimethanol, decamethylene glycol, dodecamethylene glycol, and mixtures thereof.

[0072] In one aspect, the polyol component can also include one or more polycaprolactone polyester polyols. Useful polycaprolactone polyester polyols in the technology described herein include polyester diols derived from caprolactone monomers. Polycaprolactone polyester polyols are terminated by primary hydroxyl groups. Suitable polycaprolactone polyester polyols can be made from ε-caprolactone and a difunctional initiator (such as diethylene glycol, 1,4-butanediol or any other diols listed herein. In one aspect, polycaprolactone polyester polyols are linear polyester diols derived from caprolactone monomers.

[0073] Examples of available options include CAPA TM 2202A, which is a linear polyester diol having a number average molecular weight (Mn) of 2,000; and CAPA TM 2302A, which is a linear polyester diol with an Mn of 3,000, both of which are commercially available from Perstorp Polyols Inc. These materials may also be described as polymers of 2-oxepanone and 1,4-butanediol.

[0074] Polycaprolactone polyester polyol can be made from 2-oxacycloheptanone and diol, wherein diol can be 1,4-butanediol, diethylene glycol, monoethylene glycol, 1,6-hexanediol, 2,2-dimethyl-1,3-propylene glycol or any combination thereof. In some embodiments, the diol for preparing polycaprolactone polyester polyol is linear. In some embodiments, polycaprolactone polyester polyol is made from 1,4-butanediol. In some embodiments, polycaprolactone polyester polyol has a number average molecular weight of 500 to 10,000, or 500 to 5,000, or 1,000 or even 2,000 to 4,000 or even 3,000.

[0075] Suitable hydroxy-terminated polyether intermediates include polyether polyols derived from diols or polyols having a total of 2 to 15 carbon atoms. In some embodiments, alkyl glycols or diols react with ethers including alkylene oxides (typically ethylene oxide or propylene oxide or mixtures thereof) having 2 to 6 carbon atoms. For example, hydroxyl-functional polyethers can be prepared by first reacting propylene glycol with propylene oxide and then reacting with ethylene oxide. The primary hydroxyl groups produced by ethylene oxide are more reactive than secondary hydroxyl groups, and are therefore preferred. Available commercial polyether polyols include poly(ethylene glycol) containing ethylene oxide reacted with ethylene glycol, poly(propylene glycol) containing propylene oxide reacted with propylene glycol, poly(tetramethylene ether glycol) containing water reacted with tetrahydrofuran, which can also be described as polytetrahydrofuran, and is commonly referred to as PTMEG. In some embodiments, the polyether intermediate includes PTMEG. Suitable polyether polyols also include polyamide adducts of alkylene oxides, and may include, for example, ethylenediamine adducts comprising the reaction product of ethylenediamine and propylene oxide, diethylenetriamine adducts comprising the reaction product of diethylenetriamine and propylene oxide, and similar polyamide type polyether polyols. Copolyethers may also be used in the composition. Typical copolyethers include the reaction products of THF and ethylene oxide or THF and propylene oxide. These can be purchased from BASF, such as block copolymers B and random copolymer R. The various polyether intermediates typically have a number average molecular weight (Mn) of about 300 or more, or about 500 or more, or about 700 or more, or about 1,000 or more, or about 1,450, or about 2,500 or more, or about 3,000 or more, or about 5,000 or more, or about 8,000 or more, or about 10,000 or more, as determined by analyzing the terminal functional groups. In some embodiments, the polyether intermediate includes a blend of two or more different molecular weight polyethers, such as, for example, a blend of 300Mn and 8,000MnPEG or a blend of 300Mn, 1450Mn, and 8,000MnPEG.

[0076] Suitable hydroxyl-terminated polycarbonates include those prepared by reacting diols with carbonates. U.S. Patent No. 4,131,731 is incorporated herein by reference for its disclosure of hydroxyl-terminated polycarbonates and their preparations. Such polycarbonates are linear and have terminal hydroxyl groups substantially free of other terminal groups. The basic reactants are diols and carbonates. Suitable diols are selected from alicyclic and aliphatic diols containing 4 to 40, and or even 4 to 12 carbon atoms, and polyoxyalkylene glycols containing 2 to 20 alkoxy groups and 2 to 4 carbon atoms per alkoxy group in each molecule. Suitable diols include aliphatic diols containing 4 to 12 carbon atoms, such as 1,4-butanediol, 1,5-pentanediol, neopentyl glycol, 1,6-hexanediol, 2,2,4-trimethyl-1,6-hexanediol, 1,10-decanediol, hydrogenated dilinoleyl glycol, hydrogenated dioleyl glycol, 3-methyl-1,5-pentanediol; and alicyclic diols, such as 1,3-cyclohexanediol, 1,4-cyclohexanedimethanol, 1,4-cyclohexanediol, 1,3-cyclohexanedimethanol, 1,4-endo-methylene-2-hydroxy-5-hydroxymethylcyclohexane and polyalkylene glycols. The diol used in the reaction can be a single diol or a diol mixture, depending on the desired properties in the finished product. Hydroxyl terminated polycarbonate intermediates are generally those known in the art and literature. Suitable carbonates are selected from alkylene carbonates composed of 5 to 7 ring members. Suitable carbonates used herein include ethylene carbonate, trimethylene carbonate, tetramethylene carbonate, 1,2-propylene carbonate, 1,2-butylene carbonate, 2,3-butylene carbonate, 1,2-ethylene carbonate, 1,3-pentenyl carbonate, 1,4-pentenyl carbonate, 2,3-pentenyl carbonate and 2,4-pentenyl carbonate. In addition, suitable herein are dialkyl carbonates, alicyclic carbonates and diaryl carbonates. Dialkyl carbonates can contain 2 to 5 carbon atoms in each alkyl group, and specific examples thereof are diethyl carbonate and dipropyl carbonate. Alicyclic carbonates, especially dialicyclic carbonates, can contain 4 to 7 carbon atoms in each ring structure, and can have 1 to 2 such structures. When one group is alicyclic, the other group can be an alkyl or an aryl. On the other hand, if one group is an aryl, the other can be an alkyl or an alicyclic. Examples of suitable diaryl carbonates are diphenyl carbonate, ditolyl carbonate, and dinaphthyl carbonate, which may contain from 6 to 20 carbon atoms in each aryl group.

[0077] Suitable polysiloxane polyols include α-ω-hydroxy or hydroxyalkyl terminated diols. Examples include poly(dimethylsiloxane) terminated with hydroxy or hydroxyalkyl end groups. In one aspect, the polysiloxane polyol is a hydroxy terminated polydimethylsiloxane. In one aspect, the polysiloxane polyol is selected from hydroxymethyl, hydroxyethyl or hydroxypropyl terminated polydimethylsiloxane. In one aspect, the polysiloxane polyol has a number average molecular weight in the range of 300 to 5,000, or 400 to 3,000.

[0078] The polysiloxane polyol can be obtained by a dehydrogenation reaction between polysiloxane hydride and an aliphatic polyol or polyoxyalkanol to introduce an alcoholic hydroxyl group into the polysiloxane main chain.

[0079] In one aspect, the polysiloxane polyol is selected from one or more compounds represented by the following formula:

[0080]

[0081] wherein each of R1 is independently selected from C1 to C4 alkyl, benzyl and phenyl; a and b each independently represent an integer from 0 to 8, or from 1 to 8; and c represents an integer from 3 to 50. In one aspect, each of R1 is a methyl group.

[0082] Suitable silicone polyols are commercially available from Dow Chemical, Gelest, and Sigma-Aldrich.

[0083] Alkoxylated polysiloxane polyols, copolymers of dimethylsiloxane (polydimethylsiloxane) modified with alkylene oxide units. The alkylene oxide units can be arranged in the form of random or block copolymers. One type of generally useful polydimethylsiloxane polyols are block copolymers having terminal and / or side chain blocks of polydimethylsiloxane and blocks of polyalkylene oxides, such as blocks of polyethylene oxide, polypropylene oxide, or both.

[0084]

[0085] wherein each of R3 is independently selected from C1 to C4 alkyl, benzyl and phenyl; OE and EO represent ethylene oxide residues (e.g., -CH2CH2O-); OP and PO represent propylene oxide residues (e.g., -CH2CH2CH2O- and / or -CH2CH(CH3)O-); x independently represents a range of about 0 to about 200, or about 1 to about 100, or about 2 to about 50, or about 3 to about 25, or about 5 to about 20, or about 8 to about 1 5; y independently represents an integer ranging from about 0 to about 200, or from about 1 to about 100, or from about 2 to about 50, or from about 3 to about 25, or from about 5 to about 20, or from about 8 to about 15, subject to the premise that x and y cannot all be 0 at the same time; z represents an integer ranging from about 1 to about 1000, or from about 5 to about 800, or from about 10 to about 500, or from about 15 to about 200, or from about 25 to 100; and n independently represents an integer ranging from about 1 to about 4. The OE, EO, OP and PO residues may be arranged in random, non-random or block sequence.

[0086] In one aspect, each R3 group is methyl; x independently represents an integer ranging from about 1 to about 100, or from about 2 to about 50, or from about 3 to about 25, or from about 5 to about 20; y is 0; z represents an integer ranging from about 1 to about 100; and n represents an integer ranging from about 1 to about 4.

[0087] Alkoxylated polysiloxane polyols are disclosed in US Pat. No. 5,180,843, which is incorporated herein by reference.Alkoxylated polysiloxane polyols are commercially available from Lubrizol Advanced Materials, Inc. under the trade name Silsense.

[0088] Suitable polybutadiene polyols may be selected from linear or branched hydroxyl-terminated, optionally hydrogenated polybutadiene diols.

[0089] The hydroxyl terminated polybutadiene diols useful for preparing the isocyanate terminated low free prepolymers of the presently disclosed technology are those having a number average molecular weight (Mn) of from about 500 to about 10,000 or from about 800 to about 5,000, a primary hydroxyl group content of from about 0.1 meq / g to about 2.0 meq / g or from about 0.3 meq / g to about 1.8 meq / g, a degree of hydrogenation of the olefinic sites present of from 0% to 100%, and an average content of copolymerized polymer monomers of from 0% by weight up to about 50% by weight.

[0090] The hydroxy-terminated butadiene diol contains, on average, more than one predominantly primary hydroxyl group per molecule, e.g., an average of about 1.7 to about 2.4 primary hydroxyl groups per molecule. In one aspect, the hydroxy-terminated polybutadiene has an average of at least about 2 hydroxyl groups, which are primarily located in terminal allylic positions on the polybutadiene backbone (i.e., the generally longest hydrocarbon chain of the molecule). The so-called "allylic" configuration refers to the α-allylic group of the allylic alcohol, i.e., the terminal hydroxyl group of the polymer, being bonded to a carbon atom adjacent to a double-bonded carbon atom.

[0091] The hydroxyl-terminated polybutadiene may also be combined with one or more other copolymerizable monomers. The total amount of copolymerizable monomers will not exceed 50% by weight of the hydroxyl-terminated polybutadiene copolymer on average. Copolymerizable monomers include: monoolefins; and dienes, such as ethylene, propylene, 1-butene, isoprene, chloroprene, 2,3-methyl-1,3-butadiene, 1,4-pentadiene, etc.; and ethylenically unsaturated monomers, such as acrylonitrile, methacrylonitrile, methyl styrene, methyl acrylate, methyl methacrylate, vinyl acetate, etc.

[0092] In one aspect of the presently disclosed technology, the isocyanate terminated low free polyurethane prepolymer is terminated with isocyanatohexyl groups.

[0093] In one aspect of the technology disclosed in the present invention, an isocyanate-terminated low-free polyurethane prepolymer is prepared by reacting 1,6-hexamethylene diisocyanate and a polyether polyol.

[0094] In one aspect of the technology disclosed in the present invention, an isocyanate-terminated low-free polyurethane prepolymer is prepared by reacting 1,6-hexamethylene diisocyanate and tetrahydrofuran.

[0095] Prepolymer preparation

[0096] Methods for synthesizing isocyanate-terminated polyurethane prepolymers are well known in the art. Typically, the isocyanate-terminated low-free polyurethane prepolymers of the technology disclosed in the present invention are prepared by reacting an excess of at least one polyisocyanate (component (i)) with at least one polyol (component (ii)). In one aspect, the at least one polyisocyanate is selected from diisocyanates, and the at least one polyol is selected from diols. As previously mentioned, a 2:1 ratio of at least one diisocyanate to at least one diol is employed in the reaction mixture. The ideally excessive diisocyanate ensures that the diol is fully terminated by the isocyanate moiety. A reaction mixture comprising at least one polyisocyanate (e.g., diisocyanate) and at least one polyol (e.g., diol) is heated at a temperature ranging from about 50°C to about 150°C, or from about 60°C to about 100°C for 10 minutes to 24 hours, or from 2 hours to 6 hours.

[0097] The formation of the isocyanate-terminated prepolymers of the disclosed technology can be achieved without the use of a catalyst. However, a catalyst is optionally employed in some cases, depending on the application of the final product made from the polyurethane prepared with the isocyanate-terminated low-free prepolymer. In one aspect, the reaction to form the prepolymer is uncatalyzed. The use of a catalyst may result in residual catalyst in the prepolymer reaction product, which may lead to toxicity issues for medical applications of TPUs using such prepolymers.

[0098] The isocyanate-terminated polyurethane prepolymer of the disclosed technology is a low free residual monomer polyurethane prepolymer, meaning that the polyurethane prepolymer composition contains 1.0 wt% or less of free residual polyisocyanate (e.g., diisocyanate) monomers based on the total weight of the polyurethane prepolymer. The unreacted diisocyanate residual monomers in the prepolymer reaction product are removed to a concentration ranging from more than 0 wt% to about 1.0 wt% or less, or from about 0.05 wt% to about 0.75 wt% or less, or from about 0.1 wt% to about 0.5 wt% or less, based on the total weight of the polyurethane prepolymer.

[0099] Residual polyisocyanate monomers can be removed from the polyurethane prepolymer by conventional methods known in the art. For example, methods for removing residual isocyanate-containing monomers from the polyurethane prepolymer composition include, but are not limited to, scraped film evaporation, solvent-assisted distillation or co-distillation, molecular sieves, and solvent extraction. In one aspect, reduced pressure distillation can be employed, such as, for example, thin film or stirred film evaporation under vacuum.

[0100] The amount of free diisocyanate residual monomers in the prepolymer composition can be determined by conventional methods known in the art, such as by high performance liquid chromatography (HPLC).

[0101] In one aspect, prepolymers of the presently disclosed technology and their preparation are disclosed in International Publication No. WO 2021 / 051039, which is hereby incorporated herein by reference.

[0102] Thermoplastic polyurethane

[0103] The TPU composition of the technology disclosed in the present invention is prepared by the following reaction: (a) a mixture of at least one isocyanate-terminated low-free polyurethane prepolymer as described above; (b) at least one linear aliphatic polyisocyanate, wherein the weight ratio of the at least one aliphatic polyisocyanate to the isocyanate-terminated low-free polyurethane prepolymer is in the range of about 10:1 to about 1:10, or about 1:1 to about 1:2; (c) at least one polyol component, which accounts for 0% by weight of the total weight of the thermoplastic polyurethane, or from about 5 wt % to about 80 wt %; and (d) a chain extender component comprising (iii) a first chain extender selected from at least one linear unsubstituted alkane diol containing from about 2 to about 20 carbon atoms, and (iv) a second chain extender selected from at least one cycloaliphatic diol or at least one aliphatic branched short chain diol or at least one dianhydrohexitol diol, wherein the weight ratio of the first chain extender to the second chain extender ranges from about 1:19 to about 19:1, or from about 1:1 to about 10:1, or from about 2:1 to about 5:1.

[0104] The polyurethane of the disclosed technology can be prepared using a variety of techniques known in the art. In one aspect, a preformed isocyanate-terminated low-free polyurethane prepolymer (a) is reacted with at least one linear aliphatic polyisocyanate (b), an optional polyol (c), and a chain extender component (d) comprising a first chain extender and a second chain extender as described herein. An optional catalyst and other optional additive components can be added to the reaction mixture.

[0105] The preformed isocyanate-terminated low free polyurethane prepolymer (a) can be prepared as described above or can be obtained commercially. In one aspect, the isocyanate-terminated low free polyurethane prepolymer can be obtained under the trade name Adiprene TM LFH E1192 is commercially available from Lanxess AG and is the reaction product of hexamethylene diisocyanate (HDI) and a polyether polyol having a low free HDI content (<0.1 wt %).

[0106] In one aspect, the preformed isocyanate-terminated low free polyurethane prepolymer (a), the linear aliphatic polyisocyanate (b), the optional polyol (c), the chain extender component (d), and other optional additive components are kept at a temperature of at least about 90° C. for at least about 10 minutes, or at least about 110° C., or at least about 120° C., or at least about 130° C., or at least about 140° C. for at least about 3 seconds to 2 hours or longer, or at least about 10 minutes, or at least about 20 minutes, or at least about 30 minutes, or at least about 1 hour when mixed. In some non-limiting aspects, the components are kept at a temperature of at least about 100° C., or at least about 105° C., or at least about 110° C., or at least about 125° C. to about 220° C. for at least about 10 minutes, at least about 20 minutes, or at least about 1 hour when mixed.

[0107] In one aspect, the isocyanate terminated low free polyurethane prepolymer (a) is formed as described above, and then the linear aliphatic polyisocyanate (b), optional polyol (c), chain extender component (d) and other optional additive components are introduced (mixed) into the reaction medium at the temperature range and time mentioned in the previous paragraph.

[0108] In one aspect, the process for producing the TPU of the presently disclosed technology is a process known as a one-shot polymerization process. In a one-shot polymerization process, which typically occurs in situ, reactions occur simultaneously between reaction components (a), (b), optionally (c), and (d).

[0109] In one aspect, the components of the TPU forming technology disclosed in the present invention are melt polymerized in a suitable agitator such as an internal mixer (e.g., a Banbury internal mixer) or in an extruder (e.g., a twin-screw extruder). The reaction is usually initiated at a temperature of about 90°C to about 200°C. Because the reaction is exothermic, the reaction temperature is usually increased to about 220°C to 250°C. If the reaction is carried out in a reaction extruder, the TPU polymer will leave the extruder and will usually be pelletized. Alternatively, if the reaction is carried out in a mixer or container, the TPU reaction product is poured into a block mold to solidify. Optionally, the TPU pellets or blocks can be stored at an elevated temperature to continue the reaction so that all reaction components are completely reacted. The molded TPU blocks are usually processed into a crumb form. TPU pellets and crumb products can be further melt-processed (with optional additives) on the extruder and molded into a final product form.

[0110] Alternatively, the TPU reaction components (along with optional additives) can be polymerized in an extruder as previously described and extruded or molded directly into the desired final product.

[0111] Optional additives

[0112] One or more additional additives selected from the following may be blended into the TPU composition of the presently disclosed technology: pigments, including but not limited to UV stabilizers, UV absorbers, antioxidants, lubricants, thermal stabilizers, hydrolysis stabilizers, crosslinking activators, flame retardants, layered silicates, fillers, colorants, reinforcing agents, adhesion modifiers, impact strength modifiers, radiopaque agents, antimicrobial agents, and mixtures thereof.

[0113] In one aspect, the resulting TPU has the following properties:

[0114] a) a Shore D hardness of about 20 to about 75 as measured by ASTM D2240;

[0115] b) a dry flexural modulus of about 4,000 psi to about 90,000 psi as measured by ASTM D790;

[0116] c) a wet flexural modulus of about 3,000 psi to about 50,000 psi as measured by ASTM D790;

[0117] d) an elongation at break of about 300% to about 750% as measured by ASTM D412;

[0118] e) a tensile strength of about 5,000 psi to about 10,000 psi as measured by ASTM D412;

[0119] f) a springback recovery of about 40% to about 65% as measured by ASTM D2632.

[0120] Polyisocyanate (b)

[0121] In one aspect, the at least one linear aliphatic polyisocyanate (b) is selected from C1 to C 12 Straight chain aliphatic diisocyanate. Exemplary C1 to C 12 The linear aliphatic diisocyanates include, but are not limited to, ethylene diisocyanate, 1,3-propane diisocyanate, 1,4-butane diisocyanate, 1,5-pentane diisocyanate, 1,6-hexane diisocyanate (hexamethylene diisocyanate or HDI), 1,8-octane diisocyanate, and 1,12-dodecane diisocyanate. The linear aliphatic diisocyanates may be used alone or in combination of two or more. More specifically, the linear aliphatic polyisocyanate may be HDI.

[0122] Polyol (c)

[0123] In the preparation of the TPU of the technology disclosed in the present invention, the use of polyol (c) is optional. Polyol can be used in the reaction mixture in an amount ranging from about 0 wt % to about 80 wt % based on the total weight of the polyurethane. In one aspect, if adopted in the reaction mixture, polyol (c) can be selected from any polyol known in the preparation of TPU. In one aspect, polyol component (c) is selected from the diol component as described above used in the preparation of the above-mentioned isocyanate-terminated low free polyurethane prepolymer, for example, polyether polyol, polyester polyol, polycarbonate polyol, polysiloxane polyol, polybutadiene polyol and their mixture.

[0124] In one aspect, polyol (c) is selected from polyethylene oxide, polyethylene glycol, polypropylene oxide, polypropylene glycol, polytetramethylene ether glycol, and mixtures thereof, each of which has been previously described above under prepolymer polyol component (ii), the disclosures of which are incorporated herein by reference.

[0125] Chain extender (d)

[0126] In the preparation of the TPU composition of the present disclosure, the chain extender (d) comprises (iii) a first chain extender selected from at least one linear unsubstituted alkane diol containing about 2 to about 20 carbon atoms, and (iv) a second chain extender selected from at least one cycloaliphatic diol, or at least one aliphatic branched short chain diol, or at least one dianhydrohexitol diol. The weight ratio of the first chain extender to the second chain extender ranges from about 1:19 to about 19:1, or from about 1:1 to about 10:1, or from about 2:1 to about 5:1.

[0127] In one aspect, the weight ratio of the polyol component to the total chain extender component (the first chain extender component and the second chain extender component) ranges from about 0 to about 20:1.

[0128] In one aspect, the total chain extender component (the first chain extender component and the second chain extender component) comprises from about 2 wt % to about 35 wt % of the total weight of the polyurethane composition.

[0129] In one aspect, the first chain extender (iii) is selected from at least one linear unsubstituted alkanediol containing from about 2 to about 20 carbon atoms. Exemplary first chain extenders include ethylene glycol, diethylene glycol, propylene glycol, 1,3-propanediol, dipropylene glycol, 1,3-butanediol, 1,4-butanediol (BDO), 1,5-pentanediol, 1,6-hexanediol (HDO), 1,7-heptanediol, 1,9-nonanediol, 1,11-undecanediol, 1,12-dodecanediol, and mixtures thereof.

[0130] In one aspect, the second chain extender is selected from at least one cycloaliphatic diol, or at least one aliphatic branched short chain diol, or at least one dianhydrohexitol diol. Exemplary cycloaliphatic diols include, but are not limited to, 2,2'-(cyclohexane-1,1-diyl)-diethanol, 4,4'-bicyclohexanol, 2,2,4,4-tetramethyl-1,3-cyclobutanediol, cyclopentanediol, 1,4-cyclohexanediol, 1,4-cyclohexanedimethanol (CHDM), 1,2-cyclohexanedimethanol, 1,3-cyclohexanedimethanol, 1,3-cyclododecanediol, 1,4-cyclododecanediol, 1,5 -cyclododecanediol, 1,6-cyclododecanediol, 4,4'-isopropylidene dicyclohexanol, 1-(3-hydroxypropyl)cyclohexanol, 2-(3-hydroxypropyl)cyclohexanol, 1,4-cyclohexanediethanol, 1,4-cyclohexanediethanol, 1,2-bis(hydroxymethyl)-cyclohexane, 1,2-bis(hydroxyethyl)-cyclohexane, 4,4'-isopropylidene dicyclohexanol, bis(4-hydroxycyclohexyl)methane and mixtures thereof.

[0131] Aliphatic branched short chain diols refer to diols containing an aliphatic main chain of no more than 8 carbon atoms and having at least one aliphatic side chain (or branched substituent) containing at least one carbon atom. The aliphatic side chain can be straight or branched. In one aspect, the aliphatic main chain contains 3 to 8 carbon atoms, and the aliphatic side chain is an alkyl group containing 1 to 5 carbon atoms. As is well known in chemical nomenclature conventions, the main chain contains a greater number of carbon atoms than the side chain or branched chain. Exemplary aliphatic branched short chain diols include, but are not limited to, neopentyl glycol, tripropylene glycol (e.g., [(1-methyl-1,2-ethanediyl)bis(oxy)]dipropanol), 3,3-dimethoxy-1,5-pentanediol, 2-methyl-butanediol, 2,2,4-trimethyl-1,3-pentanediol, 2-methyl-1,3-pentanediol, 2-ethyl-1,3-hexanediol, 2-methyl-1,3-propanediol, 2,2-dimethyl-1,3-propanediol, dibutyl-1,3-propanediol, 2-ethyl-1,3-hexanediol, 2-butyl-2-ethyl-1,3-propanediol, 1,4-cyclohexanedimethanol, 1,5-diol, 2,2,4-trimethyl-1,3-pentanediol, 2- ...5-diol, 2-methyl-1,3-propanediol, 2-ethyl-1,3-hexanediol, 2-butyl-2-ethyl-1,3-propanediol, 1,5-diol, 2-methyl-1,3-pentanediol, 2-ethyl-1,3-hexanediol, 2-butyl-2-ethyl-1,3-propanediol, 1,5-diol, 2-methyl-1,3 The aliphatic branched short-chain diol may be 2-methyl-1,3-propanediol. Specifically, the aliphatic branched short-chain diol may be 2-butyl-2-ethyl-1,3-propanediol.

[0132] Exemplary dianhydrohexitol diols include isosorbide (1,4:3,6-dianhydro-D-glucitol), isoidide (1,4:3,6-dianhydro-L-iditol), isomannide (1,4:3,6-dianhydro-D-mannitol), and mixtures thereof.

[0133] In one aspect, the chain extender component comprises a first chain extender selected from at least one linear unsubstituted alkane diol containing from about 2 to about 20 carbon atoms and a second chain extender selected from at least one cycloaliphatic diol. Specifically, the first chain extender can be 1,4-butanediol (BDO), and the second chain extender can be 1,3-cyclohexanedimethanol (CHDM).

[0134] In one embodiment, the first chain extender can be 1,4-butanediol (BDO), and the second chain extender can be an aliphatic branched short chain diol. Specifically, the first chain extender can be 1,4-butanediol, and the second chain extender component can be 2-methyl-1,3-propanediol. Specifically, the first chain extender component can be 1,4-butanediol, and the second chain extender component can be 2-butyl-2-ethyl-1,3-propanediol.

[0135] The technology disclosed in the present invention also provides an article made of the TPU material and / or composition described herein. The specific types of articles or products that can be made from the TPU material and / or composition of the technology disclosed in the present invention are not limited, as long as the properties of the TPU meet the specifications required by the final product. In one aspect, the TPU of the technology disclosed in the present invention can be used in medical applications. Non-limiting examples include: pacemaker heads; angiography, angioplasty, epidural catheters, thermal dilution catheters, and urology catheters; catheter connectors; medical tubing; cartilage replacements, hair replacements, joint replacements, etc., as well as for personal care applications, pharmaceutical applications, health care product applications, or any other multiple applications. In some aspects of the technology disclosed in the present invention, these articles are prepared by extrusion, injection molding, or any combination thereof.

[0136] The technology disclosed in the present invention is illustrated by the following examples, which are for illustrative purposes only and should not be considered to limit the scope of the technology or the way in which it can be practiced. Unless otherwise specifically stated, parts and percentages are by weight. Unless otherwise stated, all weights and percentages are expressed as 100% active material.

[0137] Example 1 to Example 6

[0138] A series of thermoplastic polymers, including those of the presently disclosed technology, were prepared from the components listed in Table 1. Each of the polymers was prepared by reacting the components and then forming test specimens by extrusion or molding.

[0139] Table 1 (67D)

[0140]

[0141] 1 The first chain extender.

[0142] 2 A second chain extender.

[0143] 3 Isocyanate-terminated low free prepolymer: reaction product of hexamethylene diisocyanate (HDI) and a polyether polyol having a low free HDI content (<0.1 wt%) (Adiprene TM LFH E1192).

[0144] 4 BDO = 1,4-butanediol.

[0145] 5 CHDM = 1,4-cyclohexanedimethanol.

[0146] 6 Comparative Examples.

[0147] 7 Pebax TM 7233 - a commercially available polyether block amide sold by Arkema.

[0148] 8 Aliphatic TPU.

[0149] 9 H12MDI = dicyclohexylmethane-4,4'-diisocyanate.

[0150] 10 Polytetramethylene ether glycol (1000Mn).

[0151] 11 Aromatic TPU.

[0152] 12 MDI = 4,4'-methylenebis-(phenyl isocyanate).

[0153] 13 Polytetramethylene ether glycol (650Mn).

[0154] 14 Polytetramethylene ether glycol (1400Mn).

[0155] Example 7 to Example 12

[0156] Each of the polymer samples prepared in Examples 1 to 6 was evaluated to confirm its Shore D hardness (measured by ASTM D2240), dry flexural modulus (measured by ASTM D790), wet flexural modulus (measured by ASTM D790), and its rebound elasticity (measured by ASTM D2632), elongation at break (measured by ASTM D412), tensile strength (measured by ASTM D412), rebound elasticity (measured by ASTM D2632), and softening percentage. Prior to running the Shore D hardness (ASTM D2240) and flexural modulus (ASTM D790) tests, injection molded bar test specimens (5 inches long×1 / 2 inch wide×1 / 8 inch thick) were stored at room temperature for at least 5 days and then conditioned at 23+ / -2°C, 50% RH+ / -5% for 40 hours.

[0157] The softening percentage is determined according to ASTM D790 by measuring the flexural modulus (at ambient room temperature (RT): 20°C to 25°C) of dry and wet injection molded bars (5 inches long x 1 / 2 inch wide x 1 / 8 inch thick) immersed in deionized water at 40°C for 5 days, and substituting the results into the following formula:

[0158] Softening % = [(flexural modulus 干 -Flexural modulus 湿 )×100 / flexural modulus 干

[0159] The results of all tests are shown in Table 2.

[0160] Table 2

[0161]

[0162] 1 Comparative Examples.

[0163] The results show that the TPU compositions of the disclosed technology provide better dry flexural modulus than conventional aliphatic and aromatic TPU compositions, while all other properties are comparable. The Shore D and % softening values ​​of the TPUs of Examples 7 to 9 of the disclosed technology are compared with the comparative polymers of Examples 10, 11 and 12 (including Pebax TM The % softening and Shore D values ​​of the TPUs of Examples 7 to 12 are plotted on Figure 1 middle.

[0164] Example 13 to Example 16

[0165] A series of thermoplastic polymers were prepared from the components listed in Table 3.

[0166] Table 3 (45D)

[0167]

[0168]

[0169] 1 The first chain extender.

[0170] 2 A second chain extender.

[0171] 3 Isocyanate-terminated low free prepolymer: reaction product of hexamethylene diisocyanate (HDI) and a polyether polyol having a low free HDI content (<0.1 wt%) (Adiprene TM LFH E1192).

[0172] 4 Polytetramethylene ether glycol (2000Mn)

[0173] 5 BDO = 1,4-butanediol.

[0174] 6 CHDM = 1,4-cyclohexanedimethanol.

[0175] 7 Comparative Examples.

[0176] 8 Pebax TM 4033 - a commercially available polyether block amide sold by Arkema.

[0177] 9 Aliphatic TPU

[0178] 10 H12MDI = dicyclohexylmethane-4,4'-diisocyanate.

[0179] 11 Polytetramethylene ether glycol (1000Mn)

[0180] 12 Aromatic TPU

[0181] 13 MDI = 4,4'-methylenebis-(phenyl isocyanate).

[0182] Example 17 to Example 20

[0183] Each of the polymer samples prepared in Examples 13 to 16 was evaluated using the test protocol shown in Examples 7 to 12 to confirm the following properties: Shore D hardness, dry flexural modulus, wet flexural modulus, rebound elasticity, elongation at break, tensile strength, rebound elasticity, and softening percentage. The results are shown in Table 4.

[0184] Table 4

[0185]

[0186]

[0187] 1 Comparative Examples.

[0188] The results show that compared with the commercially available benchmark Pebax TM The TPU compositions of the disclosed technology provide excellent non-softening properties while all other measured properties are comparable. The softening percentages and Shore D values ​​of these examples are plotted in Figure 1 middle.

[0189] Example 21 to Example 24

[0190] A series of thermoplastic polymers were prepared from the components listed in Table 5.

[0191] Table 5 (25D)

[0192]

[0193] 1 The first chain extender.

[0194] 2 A second chain extender.

[0195] 3 Isocyanate-terminated low free prepolymer: reaction product of hexamethylene diisocyanate (HDI) and a polyether polyol having a low free HDI content (<0.1 wt%) (Adiprene TM LFH E1192).

[0196] 4 Polytetramethylene ether glycol (2000Mn)

[0197] 5 BDO = 1,4-butanediol.

[0198] 6CHDM = 1,4-cyclohexanedimethanol.

[0199] 7 Comparative Examples.

[0200] 8 Pebax TM 2533 - a commercially available polyether block amide sold by Arkema.

[0201] 9 Aliphatic TPU

[0202] 10 H12MDI = dicyclohexylmethane-4,4'-diisocyanate.

[0203] 11 Polytetramethylene ether glycol (1000Mn)

[0204] 12 Aromatic TPU

[0205] 13 MDI = 4,4'-methylenebis-(phenyl isocyanate).

[0206] Example 25 to Example 28

[0207] Each of the polymer samples prepared in Examples 21 to 24 was evaluated using the test protocol shown in Examples 7 to 12 to confirm the following properties: Shore D hardness, dry flexural modulus, wet flexural modulus, rebound elasticity, elongation at break, tensile strength, rebound elasticity, and softening percentage. The results are shown in Table 6.

[0208] Table 6

[0209]

[0210]

[0211] 1 Comparative Examples.

[0212] The results show that compared to the commercial benchmark Pebax TMCompared to the comparative examples and conventional aliphatic and aromatic TPU comparative examples (where all samples have similar hardness), the TPU of the technology disclosed in this invention (Example 25) provides a combination of properties that are at least comparable and in some cases superior. It should be noted that the TPU of Example 25 has a softening %, tensile strength, and rebound recovery properties that are superior to the commercial benchmark of Example 26, while the comparative TPUs (Examples 27 and 28) have one or more of the other physical properties that are inferior. For example, even though the softening % of the TPUs of Examples 27 and 28 are comparable to the TPU of the technology disclosed in this invention, the tensile and rebound properties of these comparative TPUs are significantly lower, which will have an adverse effect on medical device performance. The softening percentages and Shore D values ​​of these examples are plotted in Figure 1 middle.

[0213] Example 29 to Example 32

[0214] A series of thermoplastic polymers were prepared from the components listed in Table 7.

[0215] Table 7 (30D to 60D)

[0216]

[0217] 1 The first chain extender.

[0218] 2 A second chain extender.

[0219] 3 Isocyanate-terminated low free prepolymer: reaction product of hexamethylene diisocyanate (HDI) and a polyether polyol having a low free HDI content (<0.1 wt%) (Adiprene TM LFH E1192).

[0220] 4 Polytetramethylene ether glycol (2000Mn)

[0221] 5 BDO = 1,4-butanediol.

[0222] 6 CHDM = 1,4-cyclohexanedimethanol.

[0223] Example 33 to Example 36

[0224] Each of the polymer samples prepared in Examples 29 to 32 was evaluated using the test protocol shown in Examples 7 to 12 to confirm the following properties: Shore D hardness, dry flexural modulus, wet flexural modulus, rebound elasticity, elongation at break, tensile strength, rebound elasticity, and softening percentage. The results are shown in Table 8.

[0225] Table 8

[0226]

[0227] The polymers of Examples 33 to 36 exhibited a softening percentage significantly below 20% while maintaining good tensile strength, dry flexural modulus, dry flexural modulus, elongation at break, and rebound elastic properties. The softening percentages and Shore D values ​​for these examples are plotted in Figure 1 middle.

[0228] The Shore D Durometer Value vs. % Softening properties of the polymers of the examples listed in Tables 2, 4, and 6 show a direct correlation between hardness and non-softening characteristics. As hardness increases (Shore D Durometer Value), the degree of softening in the polymer increases. On the other hand, the hardness and non-softening characteristics of the TPU of the technology disclosed in the present invention are unrelated, i.e., the degree of softening of the TPU is independent of hardness. The relationship between Shore D Durometer Hardness Value and % Softening is shown in Figure 2 middle.

[0229] Embodiment 37

[0230] The thermoplastic polymer is prepared from the components listed in Table 9

[0231] Table 9

[0232]

[0233] 1 The first chain extender.

[0234] 2 A second chain extender.

[0235] 3 Isocyanate-terminated low free prepolymer: reaction product of hexamethylene diisocyanate (HDI) and a polyether polyol having a low free HDI content (<0.1 wt%) (Adiprene TM LFH E1192).

[0236] 4 BDO = 1,4-butanediol.

[0237] 5BEPD = 2-butyl-2-ethyl-1,3-propanediol

[0238] The polymer of Example 37 was tested to confirm the following properties: Shore D hardness, dry flexural modulus, wet flexural modulus, rebound elasticity, softening, tensile strength at break, and elongation at break, and the test protocol indicated above was used. The results are shown in Table 10.

[0239] Table 10

[0240]

[0241]

[0242] 1 Wet flexural modulus determined at 40°C.

[0243] The results demonstrate that Example 37 shows a low softening value.

Claims

1. A thermoplastic polyurethane prepared from a reaction mixture, the reaction mixture comprising: (a) at least one isocyanate-terminated low free polyurethane prepolymer composition prepared by the reaction of at least one polyisocyanate component (i) and at least one polyol component (ii), wherein the low free polyurethane prepolymer composition comprises a residual polyisocyanate component in an amount of greater than about 0 wt % to about 1 wt % or less, or about 0.05 wt % or less to about 0.75 wt % or less, or about 0.1 wt % or less to about 0.5 wt % or less, based on the total weight of the low free polyurethane prepolymer, wherein the amount of the low free polyurethane prepolymer ranges from about 1 wt % to about 80 wt %, or from about 15 wt % to about 50 wt %, based on the total weight of the thermoplastic polyurethane; (b) at least one linear aliphatic polyisocyanate, wherein the weight ratio of the at least one aliphatic polyisocyanate to the low free polyurethane prepolymer ranges from about 10:1 to about 1:10, or from about 1:1 to about 1:

2. (c) at least one polyol component, said at least one polyol component comprising in the range of 0 weight %, or about 5 weight % to about 80 weight % of said total weight of said thermoplastic polyurethane; and (d) a chain extender component comprising (iii) a first chain extender selected from at least one linear unsubstituted alkane diol containing from about 2 to about 20 carbon atoms, and (iv) a second chain extender selected from at least one cycloaliphatic diol or at least one aliphatic branched short chain diol or at least one dianhydrohexitol diol, wherein the weight ratio of the first chain extender to the second chain extender ranges from about 1:19 to about 19:1, or from about 1:1 to about 10:1, or from about 2:1 to about 5:

1.

2. The thermoplastic polyurethane according to claim 1, wherein the isocyanate content of the at least one isocyanate-terminated low free polyurethane prepolymer is from about 0.2 wt% to about 15 wt%, or from about 0.5 wt% to about 8 wt%, or from about 5 wt% to about 7 wt%, based on the total weight of the at least one isocyanate-terminated low free polyurethane prepolymer.

3. The thermoplastic polyurethane according to any one of the preceding claims, wherein the at least one isocyanate terminated low free polyurethane prepolymer comprises less than about 75 wt%, or less than about 70 wt%, or less than about 65 wt% of a 2:1 stoichiometric adduct of the at least one polyisocyanate (i) and the at least one polyol component (ii), based on the total weight of the low free polyurethane prepolymer.

4. Thermoplastic polyurethane according to any one of the preceding claims, wherein the at least one isocyanate-terminated low free polyurethane prepolymer (a) is prepared from at least one polyisocyanate component (i), the at least one polyisocyanate component being selected from: 4,4'-methylenebis(phenyl isocyanate) (MDI); m-xylene diisocyanate (XDI), phenylene-1,4-diisocyanate (PPDI), 3,3'-dimethyl-4,4'-biphenylene diisocyanate (PPDI), diisocyanate (TODI), diphenylmethane-3,3'-dimethoxy-4,4'-diisocyanate, toluene diisocyanate (TDI) and naphthalene-1,5-diisocyanate, isophorone diisocyanate (IPDI), dicyclohexylmethane-4,4'-diisocyanate (H12MDI), 1,4-cyclohexyl diisocyanate (CHDI), 1,6-hexamethylene diisocyanate (HDI), decane-1,10-diisocyanate; and mixtures thereof.

5. Thermoplastic polyurethane according to any one of the preceding claims, wherein the at least one isocyanate terminated low free polyurethane prepolymer (a) is prepared from at least one polyol component (ii), the at least one polyol component being selected from the group consisting of polyether polyols, polyester polyols, polycarbonate polyols, polysiloxane polyols, alkoxylated polysiloxane polyols, polybutadiene polyols, and combinations thereof.

6. Thermoplastic polyurethane according to any one of the preceding claims, wherein the at least one isocyanate terminated low free polyurethane prepolymer (a) is prepared from a polyol (ii) selected from at least one polyether polyol selected from: polyethylene oxide, polyethylene glycol, polypropylene oxide, polypropylene glycol and polytetramethylene ether glycol.

7. Thermoplastic polyurethane according to any one of the preceding claims, wherein the at least one isocyanate-terminated low-free polyurethane prepolymer (a) is prepared by the reaction of 1,6-hexamethylene diisocyanate and polytetramethylene ether glycol.

8. Thermoplastic polyurethane according to any one of the preceding claims, wherein the at least one isocyanate-terminated low free polyurethane prepolymer (a) is terminated with isocyanatohexyl groups.

9. The thermoplastic polyurethane according to claim 6, wherein the at least one isocyanate terminated low free polyurethane prepolymer (a) contains more than about 0 wt % to about 0.5 wt % or less, or about 0.1 wt % or less, or about 0.05 wt % or less of residual 1,6-hexamethylene diisocyanate.

10. The thermoplastic polyurethane according to any one of the preceding claims, wherein the at least one isocyanate terminated low free polyurethane prepolymer (a) comprises less than about 80 wt% of a 2:1 stoichiometric adduct of the at least one polyisocyanate component (i) and the at least one polyol component (ii).

11. The thermoplastic polyurethane according to any one of the preceding claims, wherein the at least one linear aliphatic polyisocyanate component (b) is 1,6-hexamethylene diisocyanate.

12. Thermoplastic polyurethane according to any one of the preceding claims, wherein the at least one polyol component (c) is selected from the group consisting of polyether polyols, polyester polyols, polycarbonate polyols, polysiloxane polyols and polybutadiene polyols.

13. Thermoplastic polyurethane according to any one of the preceding claims, wherein the at least one polyol component (c) is a polyether polyol selected from the group consisting of polyethylene oxide, polyethylene glycol, polypropylene oxide, polypropylene glycol and polytetramethylene ether glycol.

14. The thermoplastic polyurethane according to any one of the preceding claims, wherein the polyether polyol component (c) has a number average molecular weight ranging from about 300 to about 3000.

15. The thermoplastic polyurethane according to any one of the preceding claims, wherein the polyether polyol component (c) is polytetramethylene ether glycol.

16. The thermoplastic polyurethane according to any of the preceding claims, wherein the first linear unsubstituted alkanediol chain extender (d)(iii) is selected from the group consisting of ethylene glycol, diethylene glycol, propylene glycol, 1,3-propanediol, dipropylene glycol, 1,3-butanediol, 1,4-butanediol (BDO), 1,5-pentanediol, 1,6-hexanediol (HDO), 1,7-heptanediol, 1,9-nonanediol, 1,11-undecanediol and 1,12-dodecanediol.

17. The thermoplastic polyurethane according to any of the preceding claims, wherein the second chain extender component (d)(iv) is a cycloaliphatic diol selected from the group consisting of 2,2'-(cyclohexane-1,1-diyl)-diethanol, 4,4'-bicyclohexanol, 2,2,4,4-tetramethyl-1,3-cyclobutanediol, cyclopentanediol, 1,4-cyclohexanediol, 1,4-cyclohexanedimethanol, 1,2-cyclohexanedimethanol, 1,3-cyclohexanedimethanol, 1,3-cyclododecanediol, 1,4-cyclododecanediol, 1,5-cyclododecanediol, 1,6-cyclododecanediol, 4,4'-isopropyldicyclohexanol, 1-(3-hydroxypropyl)cyclohexanol, 2-(3-hydroxypropyl)cyclohexanol, 1,4-cyclohexanediethanol, 1,4-cyclohexanediol, 1,2-bis(hydroxymethyl)-cyclohexane, 1,2-bis(hydroxyethyl)-cyclohexane, 4,4'-isopropylidene-bicyclohexanol, bis(4-hydroxycyclohexyl)methane and mixtures thereof.

18. Thermoplastic polyurethane according to any one of the preceding claims, wherein the second chain extender component (d)(iv) is an aliphatic branched short chain diol selected from the group consisting of neopentyl glycol, tripropylene glycol, 3,3-dimethoxy-1,5-pentanediol, 2-methyl-butanediol, 2,2,4-trimethyl-1,3-pentanediol, 2-methyl-1,3-pentanediol, 2-ethyl-1,3-hexanediol, 2-methyl-1,3-propanediol, 2,2-dimethyl-1,3-propanediol, dibutyl-1,3-propanediol, 2-ethyl-1,3-hexanediol, 2-butyl-2-ethyl-1,3-propanediol, 2,4-diethyl-1,5-pentanediol, 3-methyl-1,5-pentanediol, 2-ethyl-1-methyl-1,5-pentanediol, 3-tert-butyl-1,5-pentanediol, 2-methyl-2,4-pentanediol, 2,2-diethyl-1,3-propanediol, 2,2,4-trimethyl-1,3-pentanediol, 2,2-dibutyl-1,3-propanediol, 2,2-methyl-2,3-pentanediol, 3,3-dimethyl-1,2-butanediol, 3-ethyl-1,3-pentanediol, 2-butyl-1,3-propanediol, 2-butyl-2-ethyl-1,3-propanediol and mixtures thereof.

19. The thermoplastic polyurethane according to any one of the preceding claims, wherein the second chain extender component (d)(iv) is a dianhydrohexitol diol selected from the group consisting of isosorbide, isoidide, isomannide and mixtures thereof.

20. The thermoplastic polyurethane of any one of claims 1 to 17, wherein the first chain extender component is 1,4-butanediol and the second chain extender component is 1,4-cyclohexanedimethanol.

21. The thermoplastic polyurethane of any one of claims 1 to 16 or claim 18, wherein the first chain extender component is 1,4-butanediol and the second chain extender component is 2-methyl-1,3-propanediol, or wherein the first chain extender component is 1,4-butanediol and the second chain extender component is 2-butyl-2-ethyl-1,3-propanediol.

22. The thermoplastic polyurethane according to any of the preceding claims, wherein the range of the polyol component to the total chain extender component (first chain extender component and second chain extender component) is from about 0 to about 20:

1.

23. The thermoplastic polyurethane according to any one of the preceding claims, wherein the chain extender component comprises 2 wt% to 35 wt% of the total weight of the polyurethane.

24. Thermoplastic polyurethane according to any one of the preceding claims, having one or more of the following properties: a) a Shore D hardness of about 20 to about 75 as measured by ASTM D2240; b) a dry flexural modulus of about 4,000 psi to about 90,000 psi as measured by ASTM D790; c) a wet flexural modulus of about 3,000 psi to about 50,000 psi as measured by ASTM D790; d) an elongation at break of about 300% to about 750% as measured by ASTM D412; e) a tensile strength of about 5,000 psi to about 10,000 psi as measured by ASTM D412; f) a springback recovery of about 40% to about 65% as measured by ASTM D2632.

25. The thermoplastic polyurethane of any preceding claim having a % softening of 20% or less.

26. A polymer composition comprising a thermoplastic polyurethane according to any one of the preceding claims and one or more additional additives selected from the group consisting of pigments, UV stabilizers, UV absorbers, antioxidants, lubricants, heat stabilizers, hydrolysis stabilizers, crosslinking activators, flame retardants, layered silicates, fillers, colorants, reinforcing agents, adhesion modifiers, impact strength modifiers, radiopaque agents, antimicrobial agents and mixtures thereof.

27. An article comprising the thermoplastic polyurethane according to any one of claims 1 to 25.

28. The article of claim 27, wherein the article comprises: Pacemaker tips, angiographic catheters, angioplasty catheters, epidural catheters, thermodilution catheters, urology catheters, catheter connectors, medical tubing, cartilage replacements, or joint replacements.

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