Thermoplastic and elastomeric polyurethanes produced from bio-based 1,5-pentamethylene diisocyanate

Abstract

Thermoplastic and elastomeric polyurethanes (PU) are obtained from the biobased monomer pentamethylene diisocyanate (PDI) having a biobased content of at least 70% and at least one polyol selected from polyester diols, polyether diols, and combinations thereof. The thermoplastic PU is prepared by reacting the PDI and the polyol in the presence of a chain extender. The elastomeric PU is prepared by reacting the PDI and the polyol in the presence of a curing agent. In some embodiments, the thermoplastic and elastomeric PUs can include a molar ratio of PDI to polyol of at least 1.1:1. In some embodiments, the polyol can be a biobased polyol and can have a molecular weight of at least 500 g / mol. In some embodiments, thermoplastic and elastomeric PUs having a biobased content greater than 90% can be prepared.

Description

Technical Field

[0001] This specification relates to thermoplastic and elastomeric polyurethanes made from biobased 1,5-pentamethylene diisocyanate. More specifically, described herein are thermoplastic polyurethanes and polyurethane elastomers obtained from 1,5-pentamethylene diisocyanate and a polyol selected from polyester diols and / or polyether diols. In some embodiments, the polyol may be a biobased polyol. Background Art

[0002] Thermoplastic polyurethane (TPU) is a melt-processable polyurethane having a wide range of physical-mechanical, thermal, and environmental properties, and the polyurethane is a desired material in many applications, including, for example: automotive, wires and cables, breathable leisure membranes, sports and textile coatings, various pipes, hot melt adhesives, etc. Due to its excellent physical-mechanical characteristics, TPU can be considered a high-performance material.

[0003] Due to environmental concerns and sustainability goals, biobased TPU is in demand in many applications, especially in healthcare, the textile industry, sports and leisure, footwear, the automotive industry, etc. Although sustainability and environmental goals are important, sustainable TPU still needs to have excellent physical-mechanical properties.

[0004] TPU is prepared by reacting three basic building blocks, including an isocyanate, a chain extender, and a polyol, to form a linear block copolymer consisting of hard and soft segments. The hard segments are constructed by the reaction of a chain extender and a diisocyanate, while the soft segments contain the polyol. The physical-mechanical properties of TPU can be mainly controlled by the hard segments and the flexible and elastomeric properties are controlled by the soft segments.

[0005] Commercially available biobased polyester and polyether polyols can be used to prepare TPU. However, the sources of biobased isocyanates available for the synthesis of TPU are limited. TPU is typically prepared using aromatic diisocyanates (e.g., 4,4'-MDI) or aliphatic diisocyanates such as hydrogenated MDI (HMDI or H12MDI), hexamethylene diisocyanate (HDI), or isophorone diisocyanate (IPDI). Developing TPU with a high biobased content will require the use of both biobased polyester and polyether polyols and biobased diisocyanates.

[0006] Polyurethane elastomers are produced from at least three building blocks, including isocyanates, polyols, and curing agents. The final polymer structure can be linear or crosslinked. Polyurethane elastomers can include urethane cast elastomers, urethane / urea cast elastomers, and spray elastomers. Typical polyurethane elastomers can be produced from a two-component system, where the isocyanate and polyol first react to form an NCO-prepolymer, which then reacts with a curing agent. Polyurethane elastomers are conventionally prepared from aromatic isocyanates such as toluene diisocyanate (TDI), methylene diphenyl diisocyanate (MDI), carbodiimide diisocyanate, or aliphatic isocyanates such as IPDI and HMDI. Polyurethane elastomers can be prepared using both polyether polyols and polyester polyols of different molecular weights, depending on the application.

[0007] Aliphatic isocyanate-based cast elastomers do not yellow over time and are used as synthetic glass and clear coatings. Cast polyurethane / urea elastomers are also used as linings in steel pipes for long-distance transport of abrasive slurries and can withstand a wide temperature range. Due to environmental concerns, the development of bio-based polyurethane elastomers with good physicochemical properties would be desirable. Summary of the Invention

[0008] In a first aspect, a bio-based thermoplastic polyurethane (TPU) is described herein, which is obtained from the bio-based monomer pentamethylene diisocyanate (PDI) and at least one polyol optionally bio-based selected from polyester diols, polyether diols, and combinations thereof, in the presence of at least one hydroxyl-functionalized chain extender, wherein the PDI has a bio-based content of at least 70%.

[0009] In some embodiments, the TPU can be obtained by reacting an NCO-terminated prepolymer produced from the bio-based monomer PDI and the at least one polyol with the at least one chain extender.

[0010] In another aspect, a PDI-based elastomer is described herein, which is obtained from the bio-based monomer pentamethylene diisocyanate (PDI) and at least one polyol selected from polyester polyols, polyether polyols, and combinations thereof, in the presence of at least one curing agent, wherein the PDI has a bio-based content of at least 70%.

[0011] In some embodiments, the PDI-based elastomer can be obtained by reacting an NCO-terminated prepolymer produced from the bio-based monomer PDI and the at least one polyol with the at least one curing agent.

[0012] In some embodiments, the biobased monomer PDI can be obtained by a method comprising: subjecting a solution comprising cadaverine salt dissolved in an inert solvent in the presence of a tertiary amine base to a liquid-phase phosgenation reaction using a photo gas source to convert the cadaverine to PDI, wherein the phosgenation reaction comprises the steps of maintaining the reaction at a temperature range between 100 °C and 120 °C for a sufficient time to achieve a desired PDI threshold yield, wherein the amount of the tertiary amine base present causes the phosgenation reaction to proceed to completion at the temperature range.

[0013] In some embodiments, the polyol used to prepare the TPU or PDI-based elastomer is a biobased polyol, and the resulting TPU or elastomer can have a high level of biobased content, such as at least 90% biobased content. Detailed Description

[0014] Definitions

[0015] The provision of headings and other identifiers (e.g., (a), (b), (i), (ii), etc.) is for ease of reading the specification and claims only. The use of a heading or other identifier in the specification or claims does not necessarily require that the step or element be carried out in alphabetical or numerical order or the order provided by them.

[0016] In the claims and / or the specification, when used in conjunction with the term "comprising", the use of the word "a" or "an" can mean "one", but is also consistent with the meanings of "one or more", "at least one", and "one or more than one".

[0017] The use of the term "about" refers to a standard deviation of error of the apparatus or method used to determine the value for a particular value. Generally, the term "about" means up to a 10% possible variation. Thus, variations of 1%, 2%, 3%, 4%, 5%, 6%, 7%, 8%, 9%, and 10% of a particular value are included within the term "about". Unless otherwise specified, when the term "about" is used before a range, it applies to both ends of the range.

[0018] As used herein, the term "comprising" (and any form of comprising, such as "comprise" and "comprises"), "having" (and any form of having, such as "have" and "has"), "including" (and any form of including, such as "includes" and "include") or "containing" (and any form of containing, such as "contains" and "contain") is inclusive or open-ended and does not exclude additional unrecited elements or process / method steps.

[0019] The term "bio-based" as used in connection with any compound, reactant, composition, reaction product, prepolymer, and / or polyurethane described herein means that such compound, reactant, composition, reaction product, prepolymer, and / or polyurethane contains organic carbon from renewable sources, such as agricultural, plant, animal, fungal, microbial, marine, or forestry materials living in a natural environment in equilibrium with the atmosphere.

[0020] The expressions "bio-based content", "renewable content", "bio-content", "bio-based carbon content" are used interchangeably to denote the amount of bio-based carbon in any material (i.e., any compound, reactant, composition, reaction product, prepolymer, and / or polyurethane) described herein as a percentage of the total carbon in the material. In some embodiments, the bio-based content of a product (e.g., a prepolymer and / or polyurethane) can be calculated from the bio-based content of the reactants (if known). In some embodiments, the bio-based content can be determined in accordance with ASTM D6866-18.

[0021] "Polyester polyol" as used herein includes aliphatic polyesters containing at least two hydroxyl groups, i.e., compounds containing at least two hydroxyl groups and containing repeating aliphatic moieties containing at least one ester functional group. In some embodiments, the polyester polyol can contain from 2 to 6 hydroxyl groups, more preferably from 2 to 4 hydroxyl groups.

[0022] "Polyether polyol" as used herein includes aliphatic polyethers containing at least two hydroxyl groups, i.e., compounds containing at least two hydroxyl groups and containing repeating aliphatic moieties containing at least one ether functional group. In some embodiments, the polyether polyol can contain from 2 to 6 hydroxyl groups, more preferably from 2 to 4 hydroxyl groups.

[0023] As used herein, "polyester diol" includes dihydroxy aliphatic polyesters, i.e., compounds containing two terminal hydroxyl groups and containing repeating aliphatic moieties containing at least one ester functional group. In some embodiments, the polyester diol can be produced by the reaction of a diol with a dicarboxylic acid. In some embodiments, the polyester diol can have the following formula

[0024]

[0025] wherein A 1 represents a first aliphatic moiety, and A 2 represents a second aliphatic moiety. In some embodiments, the polyester diol can be produced by the reaction of a diol HO-A 1 -OH with a dicarboxylic acid of the formula HOOC-A 2 -COOH.

[0026] As used herein, "polyether diol" includes dihydroxy aliphatic polyethers, i.e., compounds containing two terminal hydroxyl groups and containing repeating aliphatic moieties containing at least one ether functional group. In some embodiments, the polyether diol can have the following formula

[0027]

[0028] wherein A 3 represents an aliphatic moiety.

[0029] As used herein, the term "aliphatic" or "aliphatic moiety" means a hydrocarbon moiety that can be straight-chain (i.e., unbranched or linear), branched, or cyclic and can be fully saturated or can contain one or more unsaturated units, provided that the hydrocarbon moiety is not aromatic. In some embodiments, the aliphatic moiety can contain a linear or branched alkylene, i.e., the divalent analog of a linear or branched alkyl. Unless otherwise specified, each aliphatic group / moiety can contain from 1 to 20 carbon atoms, such as 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, or 20 carbon atoms.

[0030] The terms "chain extender" and "curing agent" mean hydroxy-functionalized or amino-functionalized compounds that can react with diisocyanate groups to build polyurethane molecular weight. In some embodiments, the chain extender can be a diol. In some embodiments, the curing agent acts as a chain extender or crosslinking agent to form a linear or crosslinked polyurethane. In some embodiments, the curing agent can be a sterically hindered amine, diol, polyol, secondary diamine, diamine ether oligomer, and any combination thereof.

[0031] As used herein, "sterically hindered amine" refers to a compound in which the nitrogen atom of the amine molecule is partially shielded by adjacent groups such that larger molecules cannot easily approach and react with the nitrogen. In some embodiments, the sterically hindered amine can be a primary amine in which the amino group is attached to a tertiary carbon or a carbon from an aromatic ring, or can be a secondary amine in which the amino group is attached to at least one secondary or tertiary carbon or a carbon from an aromatic ring.

[0032] This disclosure relates to polyurethanes that can be prepared from biobased pentamethylene diisocyanate (PDI). PDI is a diisocyanate of the formula O═C═N-(CH 2 ) 5 -N═C═O and thus contains five methylene groups and two terminal isocyanate groups. In some embodiments, the polyurethane can be prepared from PDI and a polyol such as a polyester diol or a polyether diol, as will be described in detail below. Depending on the choice of polyol that can react with PDI, polyurethanes with various properties can be prepared. As will be described in more detail below, the preparation of the polyurethane can involve reacting an NCO-terminated prepolymer prepared from PDI and at least one polyol with a chain extender or a curing agent to provide a polyurethane that exhibits thermoplastic or elastomeric (e.g., thermoset) characteristics. The polyurethanes of this disclosure can thus exhibit interesting physicochemical properties and can be used in many different applications.

[0033] In some aspects, biobased thermoplastic polyurethanes (TPUs) are described herein that are prepared from a biobased monomer pentamethylene diisocyanate (PDI) having a biobased content of at least 70% and at least one polyol optionally biobased selected from polyester diols, polyether diols, and combinations thereof in the presence of at least one hydroxy-functional chain extender.

[0034] In other aspects, PDI-based elastomers are described herein that are prepared from a biobased monomer pentamethylene diisocyanate (PDI) having a biobased content of at least 70% and at least one polyol selected from polyester polyols, polyether polyols, and combinations thereof in the presence of at least one curing agent.

[0035] In some embodiments, the thermoplastic polyurethane and / or the polyurethane elastomer can be prepared using a combination of PDI and one or more other isocyanates. When using a combination of isocyanates, PDI is preferably used as the main isocyanate. In a preferred embodiment, PDI is used as the sole isocyanate.

[0036] Biobased pentamethylene diisocyanate (PDI)

[0037] In some embodiments, the PDI used to prepare the polyurethanes (e.g., TPU and / or elastomers) described herein can be produced by the method described in PCT / CN2020 / 120154, which is incorporated herein by reference.

[0038] Thus, in some embodiments, PDI can be produced from cadaverine salts by a method comprising:

[0039] (a) providing a light gas source;

[0040] (b) providing a solution comprising a cadaverine salt dissolved in an inert solvent in the presence of a tertiary amine base; and

[0041] (c) subjecting the solution to a liquid-phase phosgenation reaction to convert cadaverine to PDI, the phosgenation reaction comprising the steps of maintaining the reaction at a temperature range between 100 °C and 120 °C for a sufficient time to achieve a desired PDI threshold yield,

[0042] wherein the amount of the tertiary amine base present is sufficient to carry out the phosgenation reaction to completion at the temperature range.

[0043] In some embodiments, the phosgenation reaction temperature in step (c) does not exceed about 119 °C, 118 °C, 117 °C, 116 °C, 115 °C, 114 °C, 113 °C, 112 °C, 111 °C or 110 °C; and / or is not lower than 30 °C, 31 °C, 32 °C, 33 °C, 34 °C, 35 °C, 36 °C, 37 °C, 38 °C, 39 °C, 40 °C, 41 °C, 42 °C, 43 °C, 44 °C, 45 °C, 46 °C, 47 °C, 48 °C, 49 °C or 50 °C.

[0044] In some embodiments, the phosgenation reaction in (c) can comprise the steps of maintaining the reaction at a temperature between 100 °C and 115 °C, between 105 °C and 115 °C, between 110 °C and 115 °C or between 100 °C and 110 °C or at about 110 °C for a sufficient time to achieve a PDI threshold yield.

[0045] In some embodiments, the sufficient time in (c) can be at least 1.5, 2, 2.5 or 3 hours; or 1.5 to 6, 2 to 6, 2 to 5.5, 2.5 to 5.5, 2.5 to 6 or 3 to 5 hours.

[0046] In some embodiments, the phosgenation reaction in (c) can be a multi-stage phosgenation reaction, and the multi-stage phosgenation reaction at least includes: a first stage, in which the solution is heated to a first temperature such that the cadaverine reacts with phosgene from the phosgene source to produce a dichlorocarbonyl chloride intermediate, and a subsequent second stage, in which the solution is further heated to a second temperature higher than the first temperature to subject the dichlorocarbonyl chloride intermediate to dehydrochlorination, wherein the second stage includes the following steps: maintaining the reaction at a temperature between 100 °C and 120 °C for a sufficient time to achieve a PDI threshold yield.

[0047] In some embodiments, the first temperature can be from about 30 °C to 65 °C, 35 °C to 65 °C, 35 °C to 60 °C, 40 °C to 60 °C, 35 °C to 55 °C, 40 °C to 55 °C or 45 °C to 55 °C; or about 50 °C.

[0048] In some embodiments, the first stage can include maintaining the solution at the first temperature for at least 0.5, 1 or 2 hours; or 0.5 to 3, 0.5 to 2.5, 0.5 to 2, 1 to 2.5 or 1 to 2 hours.

[0049] In some embodiments, the second temperature can be at least 10 °C, 15 °C, 20 °C, 25 °C, 30 °C, 35 °C, 40 °C, 45 °C, 50 °C, 55 °C or 60 °C higher than the first temperature.

[0050] In some embodiments, the amount of the phosgene source and / or the tertiary amine base reactant used in the multi-stage phosgenation reaction is lower than the amount required to achieve the same PDI yield as the corresponding single-stage phosgenation reaction occurring only at the second temperature.

[0051] In some embodiments, the method for producing PDI uses 3 to 30, 4 to 29, 4 to 27, 4 to 24, 4 to 18, 4.5 to 18 moles of phosgene / mole of cadaverine salt. In some embodiments, the method uses at least 4, 4.5, 5, 5.5 or 6 moles of tertiary amine base / mole of cadaverine salt.

[0052] In some embodiments, the cadaverine salt can be a biobased cadaverine salt obtained by fermentation (e.g., a microorganism engineered to produce cadaverine) and / or enzymatic conversion (e.g., from lysine), and the enzymatic conversion is preferably carried out by a fixed intact cell biocatalyst to reduce impurities in the cell lysate components.

[0053] In some embodiments, cadaverine salts can be produced without distillation or otherwise subjected to temperatures that contribute to the formation of cyclic byproduct impurities. In some embodiments, the cyclic byproducts and / or other impurities described herein can include THP, piperidine, piperidine; 2-(aminomethyl)-3,4,5,6-tetrahydropyridine; 1-piperidinecarbonyl chloride; 1(2H)-pyridinecarbonyl chloride; or polymeric (insoluble) impurities that impart a darker color to the resulting PDI. As used herein, the term "impurity" refers to any compound or material present in the raw material (e.g., cadaverine salt) and / or the final product (e.g., PDI) that will negatively interfere with the performance of the final product for its intended commercial purpose. For example, any undesirable compound or material that may interfere with the performance of PDI in a polymerization reaction (e.g., in polyurethane production) is considered an impurity. In some embodiments, the content of THP or other cyclic byproduct impurities in the cadaverine salts described herein can be less than 0.1 wt%, 0.09 wt%, 0.08 wt%, 0.07 wt%, 0.06 wt%, 0.05 wt%, 0.04 wt%, 0.03 wt%, 0.02 wt%, or 0.01 wt%.

[0054] In some embodiments, the cadaverine salt is cadaverine dihydrochloride.

[0055] In some embodiments, the phosgene source is phosgene or triphosgene. In some embodiments, the phosgene source is triphosgene, and the tertiary amine base reacts with triphosgene to release phosgene for the phosgenation reaction.

[0056] In some embodiments, the phosgene source is triphosgene, and the tertiary amine base is used to promote the dissolution of the cadaverine salt to react with triphosgene to release phosgene and catalyze the subsequent phosgenation reaction in the phosgenation temperature range.

[0057] In some embodiments, the tertiary amine base is a heterocyclic amine or a tertiary amine base having an sp 2 -hybridized N atom. In some embodiments, the tertiary amine base can be pyridine.

[0058] In some embodiments, the inert solvent comprises chlorobenzene, dichlorobenzene, toluene, nitrobenzene, or any mixture thereof or consists of any of them. In some embodiments, the inert solvent is a solvent or solvent mixture having a boiling point of at least 120 °C, 125 °C, or 130 °C.

[0059] In some embodiments, the method for preparing PDI can be carried out as a one-pot synthesis, wherein the cadaverine salt and the phosgene source are slowly combined in a single container in an inert solvent in the presence of a tertiary amine base and then heated to initiate the phosgenation reaction.

[0060] In some embodiments, the PDI produced by the method described herein can be subjected to a distillation purification step.

[0061] In some embodiments, the resulting PDI has a THP or other cyclic byproduct impurity content of less than 0.1 wt%, 0.09 wt%, 0.08 wt%, 0.07 wt%, 0.06 wt%, 0.05 wt%, 0.04 wt%, 0.03 wt%, 0.02 wt%, or 0.01 wt% before undergoing one or more distillation steps.

[0062] In some embodiments, the resulting PDI has a purity of at least 99 wt%, or 99.1 wt%, 99.2 wt%, 99.3 wt%, 99.4 wt%, 99.5 wt%, 99.6 wt%, 99.7 wt%, 99.8 wt%, or 99.9 wt%.

[0063] In some embodiments, the desired PDI threshold yield is at least 50%, 55%, 60%, 65%, 70%, 75%, or 80%.

[0064] In some embodiments, the resulting PDI has a biobased content of at least 70% (e.g., at least 71%).

[0065] The biobased PDI produced and used in the present disclosure to prepare the NCO - terminated prepolymer and then the polyurethane is in monomeric form and is different from other known commercially available PDIs which are typically in trimeric form.

[0066] Polyester polyols and polyether polyols

[0067] As mentioned above, the polyurethanes of the present disclosure, i.e., TPU and / or elastomers, are prepared by reacting the PDI described herein with at least one polyol selected from polyester polyols and / or polyether polyols in the presence of a chain extender or curing agent.

[0068] In some embodiments, the TPU can be prepared from polyols, which include polyester diols and / or polyether diols, and the polyols can be biobased or non - sustainable or a mixture of both biobased and non - sustainable polyols.

[0069] In some embodiments, the elastomer can be prepared from polyester polyols and / or polyether polyols having a hydroxyl functionality ranging from 2 to 6, preferably from 2 to 4, and more preferably 2. These polyester polyols and / or polyether polyols can be biobased or non - sustainable or a mixture of both biobased and non - sustainable polyols.

[0070] In some embodiments, the polyol can be a polyester diol, a polyether diol, or any combination thereof. In some embodiments, the polyol, i.e., the polyester diol and / or the polyether diol, can be bio-based. In some embodiments, the polyol can be a bio-based polyester diol and / or polyether diol with a bio-based content of at least 90%, or at least 95%, or at least 99%, or at least 99.1%, 99.2%, 99.3%, 99.4%, 99.5%, 99.6%, 99.7%, 99.85%, or 99.9%, or about 100%. Alternatively, the polyol can be non-sustainable, or a mixture of both bio-based polyol and non-sustainable polyol can be used. When bio-based polyol is used, a very high bio-based content can be achieved in the final polyurethane, which can be advantageous from a sustainability perspective.

[0071] In some embodiments, the polyester diol can be selected from succinate-based polyester diols, adipate-based polyester diols, sebacate-based polyester diols, azelate-based polyester diols, 1,18-octadecanedioic acid-based polyester diols, or any combination thereof. In other embodiments, the polyester diol can be synthesized from organic diacids selected from succinic acid, adipic acid, sebacic acid, azelaic acid, 1,18-octadecanedioic acid, and any combination thereof and diols selected from 1,4-butanediol (1,4-BDO), 1,3-propanediol (1,3-PDO), and mixtures thereof. In a specific embodiment, the polyester diol can be selected from 1,4-BDO-adipate, 1,3-PDO-adipate, 1,4-BDO-sebacate, 1,3-PDO-sebacate, and any combination thereof. For certain applications, the polyester diol can be 1,3-PDO-sebacate. In some embodiments, a polyester diol blend can be used to adjust polyurethane properties.

[0072] In some embodiments, the polyether diol can be selected from polytrimethylene ether glycol (PO3G), polytetramethylene ether glycol (PTMEG or PTMG), polyethylene glycol, and any combination thereof. In some specific embodiments, the polyether diol can be polytrimethylene ether glycol (PO3G). In other specific embodiments, the polyether diol can include at least one polytetramethylene ether glycol (PTMEG or PTMG). In some embodiments, a polyether diol blend can be used to adjust polyurethane properties. For example, a mixture of PTMEG with different molecular weights can be used.

[0073] In some embodiments, the polyol, i.e., polyether polyol and / or polyester polyol, may have a molecular weight ranging from at least 500 g / mol, such as from 500 g / mol to about 10,000 g / mol. Thus, the polyether diol may have a molecular weight ranging from 500 to about 10,000 g / mol, from 500 to about 9,000 g / mol, 500 to about 8,000 g / mol, 500 to about 7,000 g / mol, 500 to about 6,000 g / mol, 500 to about 5,000 g / mol, 500 to about 4,000 g / mol, 500 to about 3,000 g / mol, 500 to about 2,000 g / mol, 500 to about 1,000 g / mol. In some embodiments, the polyether polyol, preferably polyether polyol diol, may have a molecular weight ranging from 500 to about 3,000 g / mol.

[0074] In some embodiments, the polyol may be dehumidified before use to achieve a water content of less than 0.1 wt%, preferably less than 0.06 wt%, based on the weight of the polyol.

[0075] Thermoplastic polyurethane based on PDI

[0076] As previously mentioned, the object of the present disclosure is to provide polyurethanes based on bio-based PDI. In some embodiments, the thermoplastic polyurethane (TPU) based on PDI may be prepared from at least one polyol and the bio-based monomer PDI (as described above) in the presence of at least one chain extender. The TPU can be obtained by first reacting at least one polyol with PDI to form an NCO-terminated prepolymer, and subsequently reacting the NCO-terminated prepolymer with at least one chain extender. Alternatively, the TPU can be obtained by reacting PDI with at least one polyol and at least one chain extender in a one-step synthesis.

[0077] In some embodiments, the TPU may be prepared such that the molar ratio of PDI to polyol to chain extender may range from 1.5:1:0.5 to 4:1:3. In other embodiments, the molar ratio of PDI to polyol to chain extender used to prepare the TPU may be from about 1.5:1:0.5 to about 3:1:2. In a further embodiment, the molar ratio of PDI to polyol to chain extender may be from about 2:1:1 to about 3:1:1. The ratios of the respective components can be determined and calculated to adjust the physicochemical properties of the TPU.

[0078] As mentioned above, in some embodiments, the TPU can be obtained by first preparing an NCO-terminated prepolymer in the presence of a chain extender. In some embodiments, the NCO-terminated prepolymer can contain an excess of isocyanate remaining in the product, and it can be referred to as a "quasi-prepolymer". Thus, the expression "NCO-terminated prepolymer" as used in this specification includes prepolymers and / or quasi-prepolymers.

[0079] In some embodiments, the NCO-terminated prepolymer can be produced using a moisture-free polyol. For example, the polyol can be dried before preparing the NCO-terminated prepolymer to achieve a water content of less than 0.1 wt%, preferably less than 0.06 wt%, based on the weight of the polyol.

[0080] The NCO-terminated prepolymer can be prepared by mixing PDI and the polyol in the desired ratio and heating the mixture. In some embodiments, the progress of the reaction can be monitored by NCO% titration. In some embodiments, the NCO-terminated prepolymer can be produced by reacting PDI and the polyol in a molar ratio of 1.1:1 to 10:1. In some embodiments, the NCO-terminated prepolymer can be produced by reacting PDI and the polyol in a molar ratio of at least 2:1. In some embodiments, the molar ratio of PDI to the polyol can be from 1.5:1 to 4:1, or from 1.5:1 to 3.5:1, or from 1.5:1 to 3:1, or from 2:1 to 3:1. In some embodiments, the NCO-terminated prepolymer can be produced by reacting PDI and the polyol by heating at a temperature ranging from about 50°C to about 120°C. In some embodiments, the NCO-terminated prepolymer can be produced by mixing PDI and the polyol in the absence of any catalyst.

[0081] As mentioned above, the PDI is bio-based and can have a bio-based content of at least 70%. When using bio-based polyols (i.e., bio-based polyether diols and / or bio-based polyester diols) to prepare the NCO-terminated prepolymer, a very high bio-based content can be achieved in the NCO-terminated prepolymer, which is advantageous from a sustainability perspective. In some embodiments, the NCO-terminated prepolymer can achieve a bio-based content of at least 90%. In some embodiments, the NCO-terminated prepolymer can have a bio-based content ranging from about 90% to about 95%, or from about 90% to about 96%, or from about 90% to about 97%, or from about 90% to about 98%, or from about 90% to about 99%, or from about 90% to about 100%. In some embodiments, the bio-based content of the NCO-terminated prepolymer can be about 90%, or about 91%, or about 92%, or about 93%, or about 94%, or about 95%, or about 96%, or about 97%, or about 98%, or about 99%, or about 99.5%, or about 99.6%, or about 99.7%, or about 99.8%, or about 99.9%, or about 100%.

[0082] In some embodiments, the NCO-terminated prepolymer can also be characterized by a viscosity in the range of from about 100 cps to about 10,000 cps, or from about 100 cps to about 9,000 cps, or from about 100 cps to about 8,000 cps, or from about 100 cps to about 7,000 cps, or from about 200 cps to about 10,000 cps, or from about 200 cps to about 9,000 cps, or from about 200 cps to about 8,000 cps, or from about 200 cps to about 7,000 cps, or from about 300 cps to about 10,000 cps, or from about 300 cps to about 9,000 cps, or from about 300 cps to about 8,000 cps, or from about 300 cps to about 7,000 cps, or from about 400 cps to about 10,000 cps, or from about 400 cps to about 9,000 cps, or from about 400 cps to about 8,000 cps, or from about 400 cps to about 7,000 cps, or from about 500 cps to about 10,000 cps, or from about 500 cps to about 9,000 cps, or from about 500 cps to about 8,000 cps, or from about 500 cps to about 7,000 cps at 70 °C. In some embodiments, the viscosity of the NCO-terminated prepolymer at 70 °C can particularly be from about 500 cps to about 7,000 cps.

[0083] Suitable chain extenders for preparing TPU are known in the art. They can be low molecular weight molecules, such as low molecular weight diols, which will allow the construction of polyurethanes and increase the block length of the hard segments. In some embodiments, the chain extender can be selected from 1,3-PDO, butanediol, pentanediol, hexanediol, ethylene glycol, propylene glycol, hydroquinone bis(2-hydroxyethyl) ether (HQEE), 1,3-bis(2-hydroxyethyl) resorcinol (HER), cyclohexanedimethanol (CHDM), 3-methyl-1,5-pentanediol, 2-butyl-2-ethyl-1,3-propanediol, and any combination thereof. In some embodiments, the chain extender can be a bio-based chain extender. In certain embodiments, the chain extender is selected from bio-based 1,3-PDO and bio-based 1,4-BDO. In other embodiments, the chain extender has an odd number of carbon atoms. In a specific embodiment, the chain extender is bio-based 1,3-PDO.

[0084] In some embodiments, TPU can be prepared by reacting an NCO-terminated prepolymer with a chain extender under heating with or without a catalyst. Alternatively, TPU can be prepared by reacting a polyol, PDI, and a chain extender in a single synthesis step under heating with or without a catalyst. Conventional catalysts for polyurethane synthesis can be used. In some embodiments, the prepolymer can be heated before mixing with the chain extender. In addition, additives such as (by way of example) pigments, flame retardants, fillers, colorants, processing aids, plasticizers, stabilizers, antioxidants, and release agents can also be added to the mixture. In some embodiments, the obtained TPU can be post-cured using conventional methods.

[0085] The bio-based TPU prepared according to the present disclosure can have a bio-based content ranging from about 90% to about 95%, or from about 90% to about 96%, or from about 90% to about 97%, or from about 90% to about 98%, or from about 90% to about 99%, or from about 90% to about 100%. In some embodiments, the bio-based TPU can have a bio-based content of about 90%, or about 91%, or about 92%, or about 93%, or about 94%, or about 95%, or about 96%, or about 97%, or about 98%, or about 99%, or about 99.5%, or about 99.6%, or about 99.7%, or about 99.8%, or about 99.9%, or about 100%.

[0086] In some embodiments, the TPU of the present disclosure can have various properties and physicochemical characteristics. For example, the TPU can exhibit a hard segment content ranging from about 10 wt% to about 40 wt%, or from about 10 wt% to about 30 wt%, or from about 10 wt% to about 20 wt%, or from about 15 wt% to about 40 wt%, or from about 15 wt% to about 30 wt%, or from about 15 wt% to about 20 wt%, or from about 20 wt% to about 40 wt%, or from about 20 wt% to about 30 wt%, or from about 25 wt% to about 40 wt%, or from about 25 wt% to about 30 wt%. In some embodiments, the TPU can exhibit a hard segment content from about 13 wt% to about 18 wt%.

[0087] In some embodiments, a TPU having a hard segment content from about 20 wt% to about 30 wt% can be obtained from the bio-based PDI described herein and a bio-based 1,3-PDO-sebacate polyester diol having a molecular weight of about 1000 g / mol as the polyol using a bio-based 1,3-PDO chain extender and a molar ratio of PDI to bio-based polyol to chain extender of about 2:1:1.

[0088] In some embodiments, a TPU having a hard segment content from about 25 wt% to about 30 wt% can be obtained from the bio-based PDI described herein and a bio-based 1,3-PDO-sebacate polyester diol having a molecular weight of about 1000 g / mol as the polyol using a bio-based 1,3-PDO chain extender and a molar ratio of PDI to bio-based polyol to chain extender of about 2:1:1.

[0089] In some embodiments, a TPU having a hard segment content from about 10 wt% to about 20 wt% can be obtained from the bio-based PDI described herein and a bio-based 1,3-PDO-sebacate polyester diol having a molecular weight of about 2000 g / mol as the polyol using a bio-based 1,3-PDO chain extender and a molar ratio of PDI to bio-based polyol to chain extender of about 2:1:1.

[0090] In some embodiments, a TPU having a hard segment content from about 13 wt% to about 18 wt% can be obtained from the bio-based PDI described herein and a bio-based 1,3-PDO-sebacate polyester diol having a molecular weight of about 2000 g / mol as the polyol using a bio-based 1,3-PDO chain extender and a molar ratio of PDI to bio-based polyol to chain extender of about 2:1:1.

[0091] In some embodiments, the TPU can be characterized by its tensile stress-strain properties such as tensile strength, elongation at break, modulus, tensile permanent set, toughness.

[0092] In some embodiments, a TPU can be obtained that has a tensile stress at break of at least 2000 psi, or at least 2500 psi, or at least 3000 psi at room temperature.

[0093] In some embodiments, a TPU having a tensile stress at break of at least 3000 psi at room temperature can be obtained from the bio-based PDI and bio-based 1,3-PDO-sebacate polyester diol described herein using a bio-based 1,3-PDO chain extender.

[0094] The bio-based TPUs of the present disclosure can be used in a variety of applications. In some embodiments, they can be used for, but are not limited to, the production of footwear, eyewear, pipes, tubing, hoses, rollers, wheels, gaskets, seals, hot melt adhesives, expandable TPU, belts, wire coatings, metal coatings, pipe coatings, screen coatings, laminates, labels, inflatables, textile coatings, apparel, barrier films, sporting goods, or medical devices.

[0095] PDI-based polyurethane elastomers

[0096] As previously mentioned, the present disclosure also aims to provide polyurethane elastomers that can be prepared from the bio-based PDI described herein. In some embodiments, PDI-based elastomers can be prepared by reacting the bio-based monomer PDI and at least one polyol in the presence of at least one curing agent as described herein. These PDI-based polyurethane elastomers can include urethane cast elastomers, urethane / urea cast elastomers, and spray elastomers.

[0097] PDI-based elastomers can be obtained by first reacting at least one polyol with PDI to form an NCO-terminated prepolymer, and subsequently reacting the NCO-terminated prepolymer with at least one curing agent. Alternatively, PDI-based elastomers can be obtained by reacting PDI with at least one polyol and at least one curing agent in a one-step synthesis. In the case of obtaining PDI-based elastomers by first preparing an NCO-terminated prepolymer, the NCO-terminated prepolymer can be prepared as described above for the preparation of TPU.

[0098] In some embodiments, elastomers can be prepared such that the molar ratio of PDI to polyol ranges from 1.1:1 to 10:1. In other embodiments, the range of the molar ratio of PDI to polyol can be from 1.5:1 to 4:1. In further embodiments, the elastomers can include a molar ratio of PDI to polyol from 2:1 to 3:1. The ratios of the components can be determined and calculated to adjust the physicochemical properties of the elastomers.

[0099] Examples of curing agents include sterically hindered amines (e.g., hindered diamine curing agents), secondary diamine curing agents, short diol curing agents, polyols, diamine ether oligomers such as primary diamine ether oligomers, and mixtures thereof. Suitable curing agents for preparing polyurethane elastomers are known in the art. In some embodiments, the curing agent can comprise at least one sterically hindered diamine. In some embodiments, the sterically hindered diamine can comprise two primary amino groups, one primary amino group and one secondary amino group, or two secondary amino groups. In some embodiments, the sterically hindered diamine used to prepare the elastomer can include aromatic diamines. Examples of sterically hindered diamines include dimethylthio-toluenediamine (DMTDA), diethyltoluenediamine such as 3,5-diethyltoluene-2,4-diamine and 3,5-diethyltoluene-2,6-diamine or mixtures thereof), or 4,4'-methylene-bis(2-chloroaniline) (MOCA). These sterically hindered amines can be used in combination. In some embodiments, the curing agent can include a diamine ether oligomer, i.e., a diamine attached to a polyether backbone typically based on ethylene oxide (EO), propylene oxide (PO), or a mixture of such compounds. Examples of such diamine ether oligomers are products sold under the trade name In some embodiments, in the case where the preparation of the PDI-based elastomer involves the preparation of an NCO-terminated prepolymer, the curing agent can react with the NCO-terminated prepolymer at an NCO-terminated prepolymer to diamine molar ratio of from about 0.95:1 to about 1.10:1, such as about 1.05:1.

[0100] In some embodiments, the PDI-based elastomer can be prepared by reacting a polyol, PDI, and a curing agent with or without a catalyst under heating or by reacting an NCO-terminated prepolymer with a curing agent. Conventional catalysts for polyurethane synthesis can be used. In some embodiments, the prepolymer can be heated before mixing with the chain extender. Additionally, additives such as (by way of example) pigments, flame retardants, fillers, colorants, processing aids, plasticizers, stabilizers, antioxidants, mold release agents can also be added to the mixture.

[0101] Depending on whether bio-based polyols are used, the polyurethane elastomer will have a potentially variable bio-based content. The bio-based content provided at least by the PDI will be counted towards the bio-based content of the polyurethane elastomer. The bio-based content of the elastomer based on PDI can vary, for example, from about 20% to about 100%. In some embodiments, the bio-based content of the elastomer based on PDI can vary from about 30% to about 100%, from about 40% to about 100%, from about 50% to about 100%, from about 60% to about 100%, from about 70% to about 100%, from about 80% to about 100%, or from about 90% to about 100%, such as at least 20%, at least 30%, at least 40%, at least 50%, at least 60%, at least 70%, at least 80%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, or at least 99%.

[0102] In some embodiments, the elastomer based on PDI can be characterized by various physicochemical properties. Among the properties of interest, by way of example, mention can be made of hardness, resilience, tensile strength, elongation at break, abrasion resistance, etc.

[0103] In some embodiments, both the hardness and resilience exhibited by the PDI-based elastomer of the present disclosure can be higher than those of an isophorone diisocyanate-based elastomer (IPDI-based elastomer), where the IPDI-based elastomer is prepared using the same polyol, the same curing agent, and in the same molar ratio and conditions as the PDI-based elastomer. This behavior is somewhat unexpected because the hard segment concentration of the PDI-based elastomer is lower than that of the IPDI-based hard segments, which would typically result in lower hardness. In some embodiments, the resilience of the PDI-based elastomer can be at least 1.2 times that of the IPDI-based elastomer, where the IPDI-based elastomer is prepared using the same polyol, the same curing agent, and in the same conditions as the PDI-based elastomer. "Same conditions" means for the synthesis of the elastomer in a single-step or by preparing an NCO-terminated polymer, substantially the same or equivalent molar ratios of the reactants (PDI, polyol, curing agent) and substantially the same or equivalent reaction parameters such as temperature and reaction time.

[0104] In other embodiments, both the tensile strength at break and the elongation at break at room temperature exhibited by the PDI-based elastomer can be higher than those of an IPDI-based elastomer prepared using the same polyol, the same curing agent, and in the same molar ratio and conditions as the PDI-based elastomer. In some embodiments, the tensile strength at break of the PDI-based elastomer at room temperature can be at least 1.8 times that of the IPDI-based elastomer at room temperature.

[0105] In other embodiments, the abrasion resistance exhibited by the PDI-based elastomer can be higher than that of an IPDI-based elastomer prepared using the same polyol, the same curing agent, and in the same molar ratio and the same conditions as the PDI-based elastomer.

[0106] In some embodiments, the tear strength exhibited by the PDI-based elastomer can also be higher than that of an IPDI-based elastomer prepared using the same polyol, the same curing agent, and in the same molar ratio and the same conditions as the PDI-based elastomer.

[0107] In some embodiments, the PDI-based elastomers of the present disclosure are castable and can qualify as cast elastomers, i.e., elastomers that can be stretched and can recover their initial form upon release. These elastomers can be thermosetting, as can natural and synthetic rubbers. Alternatively, elastomers obtained from bio-based PDI can be sprayable elastomers.

[0108] The PDI-based elastomers of the present disclosure can be used in a variety of applications. In some embodiments, they can be used in, but are not limited to, the production of footwear (e.g., soles), linings, metal coatings, pump seals, rod wipers, snow plow blades, valves, wheels, tires, agitator blades, rollers, rolls, gaskets, seals, pulleys, bumpers, shock absorbers, bushings, bearings, wear strips, skateboards, machine parts, housings, escalator parts, couplings, clamps, grommets, hammers, striker pads, wood sorting pads, gears, or sprockets.

[0109] Project

[0110] In some aspects, the present disclosure relates to one or more of the following items.

[0111] Item 1. A bio-based thermoplastic polyurethane (TPU), said bio-based thermoplastic polyurethane being obtained from the bio-based monomer pentamethylene diisocyanate (PDI) and at least one polyol, optionally bio-based, selected from polyester diols, polyether diols and combinations thereof, in the presence of at least one hydroxyl-functionalized chain extender, wherein said PDI has a bio-based content of at least 70%.

[0112] Item 2. The bio-based TPU according to Item 1, wherein PDI is used as the sole isocyanate.

[0113] Item 3. The bio-based TPU according to Item 1 or 2, said polyester diol being optionally bio-based and comprising succinate-based polyester diols, adipate-based polyester diols, sebacate-based polyester diols, azelate-based polyester diols, 1,18-octadecanedioic acid-based polyester diols, or any combination thereof.

[0114] Item 4. The bio-based TPU according to any one of Items 1 to 3, wherein said polyester diol is optionally bio-based and is synthesized from organic diacids selected from succinic acid, adipic acid, sebacic acid, azelaic acid, 1,18-octadecanedioic acid and any combination thereof and diols selected from 1,4-butanediol (1,4-BDO), 1,3-propanediol (1,3-PDO) and mixtures thereof.

[0115] Item 5. The bio-based TPU according to any one of Items 1 to 4, wherein said polyester diol is optionally bio-based and is selected from 1,4-BDO-adipate, 1,3-PDO-adipate, 1,4-BDO-sebacate, 1,3-PDO-sebacate and any combination thereof.

[0116] Item 6. The bio-based TPU according to any one of Items 1 to 5, wherein said polyester diol is bio-based 1,3-PDO-sebacate.

[0117] Item 7. The bio-based TPU according to any one of Items 1 to 6, wherein said polyether diol is optionally bio-based and is selected from polytrimethylene ether glycol (PO3G), polytetramethylene ether glycol (PTMEG or PTMG), polyethylene glycol and any combination thereof.

[0118] Item 8. The bio-based TPU according to any one of Items 1 to 7, wherein the polyether diol is bio-based polytrimethylene ether glycol (PO3G).

[0119] Item 9. The bio-based TPU according to any one of Items 1 to 8, wherein said polyester diol and / or said polyether diol is bio-based and has a bio-based content of at least 99%.

[0120] Item 10. The biobased TPU according to any one of Items 1 to 9, wherein the polyol has a molecular weight of at least 500 g / mol, such as in the range from 500 to about 10,000 g / mol, preferably in the range from 500 to about 3,000 g / mol.

[0121] Item 11. The biobased TPU according to any one of Items 1 to 10, wherein the biobased TPU has a biobased content of at least 90%.

[0122] Item 12. The biobased TPU according to any one of Items 1 to 11, wherein the biobased TPU has a biobased content from about 90% to about 95%, or from about 90% to about 96%, or from about 90% to about 97%, or from about 90% to about 98%, or from about 90% to about 99%, or from about 90% to about 100%.

[0123] Item 13. The biobased TPU according to any one of Items 1 to 12, wherein the chain extender is selected from 1,3-PDO, butanediol, pentanediol, hexanediol, ethylene glycol, propylene glycol, hydroquinone bis(2-hydroxyethyl) ether (HQEE), 1,3-bis(2-hydroxyethyl) resorcinol (HER), cyclohexanedimethanol (CHDM), 3-methyl-1,5-pentanediol, 2-butyl-2-ethyl-1,3-propanediol, and any combination thereof.

[0124] Item 14. The biobased TPU according to any one of Items 1 to 13, wherein the chain extender is a biobased chain extender.

[0125] Item 15. The biobased TPU according to any one of Items 1 to 14, wherein the chain extender is selected from biobased 1,3-PDO and biobased 1,4-BDO.

[0126] Item 16. The biobased TPU according to any one of Items 1 to 15, wherein the chain extender has an odd number of carbon atoms.

[0127] Item 17. The biobased TPU according to any one of Items 1 to 16, wherein the chain extender is biobased 1,3-PDO.

[0128] Item 18. The biobased TPU according to any one of Items 1 to 17, wherein the molar ratio of PDI to polyol to chain extender is from about 1.5:1:0.5 to about 4:1:3, preferably from about 1.5:1:0.5 to about 3:1:2, more preferably from 2:1:1 to 3:1:1.

[0129] Item 19. The biobased TPU according to any one of Items 1 to 18, wherein the TPU is obtained by reacting an NCO-terminated prepolymer produced from the biobased monomer PDI and the at least one polyol with the at least one chain extender.

[0130] Item 20. The biobased TPU according to Item 19, wherein the NCO-terminated prepolymer is produced by reacting the PDI and the polyol at a molar ratio of 1.1:1 to 10:1 by heating at a temperature ranging from about 50 °C to about 120 °C.

[0131] Item 21. The biobased TPU according to Item 19 or 20, wherein the NCO-terminated prepolymer is produced by reacting the PDI and the biobased polyol at a molar ratio of at least 2:1.

[0132] Item 22. The biobased TPU according to any one of Items 19 to 21, wherein the NCO-terminated prepolymer is produced by mixing the PDI and the biobased polyol in the absence of any catalyst.

[0133] Item 23. The biobased TPU according to any one of Items 19 to 22, wherein the NCO-terminated prepolymer is produced using a dehumidified biobased polyol.

[0134] Item 24. The biobased TPU according to Item 23, wherein the dehumidified biobased polyol has a water content of less than 0.1 wt%, preferably less than 0.06 wt%, based on the weight of the polyol.

[0135] Item 25. The biobased TPU according to any one of Items 19 to 24, wherein the NCO-terminated prepolymer has a biobased content of at least 90%.

[0136] Item 26. The biobased TPU according to any one of Items 19 to 25, wherein the NCO-terminated prepolymer has a biobased content of from about 90% to about 95%, or from about 90% to about 96%, or from about 90% to about 97%, or from about 90% to about 98%, or from about 90% to about 99%, or from about 90% to about 100%.

[0137] Item 27. The biobased TPU according to any one of Items 19 to 26, wherein the NCO-terminated prepolymer has a viscosity at 70 °C ranging from about 100 cps to about 10,000 cps, preferably from about 500 cps to about 7,000 cps.

[0138] Item 28. The bio-based TPU according to any one of Items 19 to 27, wherein the reaction of the NCO-terminated prepolymer with the chain extender is carried out under heating with or without a catalyst.

[0139] Item 29. The bio-based TPU according to any one of Items 1 to 28, wherein the TPU has a hard segment content ranging from about 10 wt% to about 40 wt%.

[0140] Item 30. The bio-based TPU according to Item 1, the bio-based TPU is obtained from pentamethylene diisocyanate (PDI) with a bio-based content of at least 70% and a bio-based 1,3-PDO-sebacate polyester diol with a molecular weight of about 1000 g / mol, the chain extender is bio-based 1,3-PDO, the molar ratio of PDI to the bio-based polyol to the chain extender is about 2:1:1, and wherein the TPU has a hard segment content ranging from about 20 wt% to about 30 wt%.

[0141] Item 31. The bio-based TPU according to Item 30, wherein the TPU has a hard segment content ranging from about 25 wt% to about 30 wt%.

[0142] Item 32. The bio-based TPU according to Item 1, the bio-based TPU is obtained from pentamethylene diisocyanate (PDI) with a bio-based content of at least 70% and a bio-based 1,3-PDO-sebacate polyester diol with a molecular weight of about 2000 g / mol, the chain extender is bio-based 1,3-PDO, the molar ratio of PDI to the bio-based polyol to the chain extender is about 2:1:1, and wherein the TPU has a hard segment content ranging from about 10 wt% to about 20 wt%.

[0143] Item 33. The bio-based TPU according to Item 32, wherein the TPU has a hard segment content ranging from about 13 wt% to about 18 wt%.

[0144] Item 34. The bio-based TPU according to any one of Items 1 to 33, wherein the TPU is characterized by a breaking tensile stress of at least 3000 psi at room temperature.

[0145] Item 35. The bio-based TPU according to Item 1, the bio-based TPU is obtained from pentamethylene diisocyanate (PDI) with a bio-based content of at least 70% and a bio-based 1,3-PDO-sebacate polyester diol, the chain extender is bio-based 1,3-PDO, and wherein the TPU is characterized by a breaking tensile stress of at least 3000 psi at room temperature.

[0146] Item 36. The biobased TPU according to any one of Items 1 to 35, wherein the PDI has a biobased content of at least 71%.

[0147] Item 37. Use of the biobased TPU according to any one of Items 1 to 36 for the production of footwear, pipes, tubes, hoses, rollers, wheels, gaskets, seals, hot melt adhesives, expandable TPU, belts, wire coatings, metal coatings, pipe coatings, sieve coatings, laminates, labels, inflatables, textile coatings, clothing, barrier films, sporting goods or medical devices.

[0148] Item 38. A PDI-based elastomer obtained from the biobased monomer pentamethylene diisocyanate (PDI) and at least one polyol selected from polyester polyols, polyether polyols and combinations thereof in the presence of at least one curing agent, wherein the PDI has a biobased content of at least 70%.

[0149] Item 39. The PDI-based elastomer according to Item 38, wherein the PDI-based elastomer has a biobased content ranging from about 20% to about 100%.

[0150] Item 40. The PDI-based elastomer according to Item 38 or 39, wherein the polyester polyol is a succinate-based polyester diol, an adipate-based polyester diol, a sebacate-based polyester diol, a azelate-based polyester diol, an 1,18-octadecanedioic acid-based polyester diol, or any combination thereof.

[0151] Item 41. The PDI-based elastomer according to any one of Items 38 to 40, wherein the polyester polyol is optionally biobased and is synthesized from organic diacids selected from succinic acid, adipic acid, sebacic acid, azelaic acid, 1,18-octadecanedioic acid and any combination thereof and diols selected from 1,4-butanediol (1,4-BDO), 1,3-propanediol (1,3-PDO) and mixtures thereof.

[0152] Item 42. The PDI-based elastomer according to any one of Items 38 to 41, wherein the polyester polyol is selected from 1,4-BDO-adipate, 1,3-PDO-adipate, 1,4-BDO-sebacate, 1,3-PDO-sebacate and any combination thereof.

[0153] Item 43. The PDI-based elastomer according to any one of Items 38 to 42, wherein the polyester polyol is 1,3-PDO-sebacate.

[0154] Item 44. The PDI-based elastomer according to any one of Items 38 to 43, wherein the polyester polyol is a bio-based polyester polyol.

[0155] Item 45. The PDI-based elastomer according to any one of Items 38 to 44, wherein the polyether polyol is selected from polytrimethylene ether glycol (PO3G), polytetramethylene ether glycol (PTMEG or PTMG), polyethylene glycol, and any combination thereof.

[0156] Item 46. The PDI-based elastomer according to any one of Items 38 to 45, wherein the polyether polyol comprises at least one polytetramethylene ether glycol (PTMEG or PTMG).

[0157] Item 47. The PDI-based elastomer according to any one of Items 38 to 46, wherein the polyether polyol is a bio-based polyether polyol.

[0158] Item 48. The PDI-based elastomer according to any one of Items 38 to 47, wherein the polyester polyol and / or the polyether polyol has a bio-based content of at least 99%.

[0159] Item 49. The PDI-based elastomer according to any one of Items 38 to 48, wherein the polyol has a molecular weight of at least 500 g / mol, preferably in the range of from 500 to about 10,000 g / mol, more preferably in the range of from 500 to about 3000 g / mol.

[0160] Item 50. The PDI-based elastomer according to any one of Items 38 to 49, wherein the curing agent is selected from sterically hindered amines, diols, polyols, secondary diamines, diamine ether oligomers, and any combination thereof.

[0161] Item 51. The PDI-based elastomer according to any one of Items 38 to 50, wherein the curing agent comprises a sterically hindered diamine, and the sterically hindered diamine comprises an aromatic diamine having two primary amino groups or having one primary amino group and one secondary amino group or having two secondary amino groups.

[0162] Item 52. The PDI-based elastomer according to any one of Items 38 to 51, wherein the curing agent comprises at least one sterically hindered diamine, including an aromatic diamine.

[0163] Item 53. The PDI-based elastomer according to any one of Items 38 to 52, wherein the curing agent comprises dimethylthio-toluenediamine (DMTDA), diethyltoluenediamine (e.g., 3,5-diethyltoluene-2,4-diamine, 3,5-diethyltoluene-2,6-diamine, or a mixture thereof), 4,4'-methylene-bis(2-chloroaniline) (MOCA), or any mixture thereof.

[0164] Item 54. The PDI-based elastomer according to any one of Items 38 to 53, wherein the elastomer is obtained by reacting an NCO-terminated prepolymer produced from the biobased monomer PDI and the at least one polyol with the at least one curing agent.

[0165] Item 55. The PDI-based elastomer according to Item 54, wherein the curing agent reacts with the NCO-terminated prepolymer at an NCO-terminated prepolymer to curing agent molar ratio of from about 0.95:1 to about 1.10:1, preferably about 1.05:1.

[0166] Item 56. The PDI-based elastomer according to Item 54 or 55, wherein the NCO-terminated prepolymer is produced by reacting the PDI and the polyol by heating at a temperature ranging from about 50°C to about 120°C.

[0167] Item 57. The PDI-based elastomer according to any one of Items 54 to 56, wherein the NCO-terminated prepolymer is produced by mixing the PDI and the biobased polyol in the absence of any catalyst.

[0168] Item 58. The PDI-based elastomer according to any one of Items 54 to 57, wherein the NCO-terminated prepolymer is produced using a dehumidified polyol.

[0169] Item 59. The PDI-based elastomer according to Item 58, wherein the dehumidified polyol has a water content of less than 0.1 wt%, preferably less than 0.06 wt%, based on the weight of the polyol.

[0170] Item 60. The PDI-based elastomer according to any one of Items 54 to 59, wherein the NCO-terminated prepolymer has a viscosity at 70°C ranging from about 100 cps to about 10,000 cps, preferably from about 500 cps to about 10,000 cps.

[0171] Item 61. The PDI-based elastomer according to any one of Items 54 to 60, wherein the reaction of the NCO-terminated prepolymer with the at least one sterically hindered diamine is carried out under heating with or without a catalyst.

[0172] Item 62. The PDI-based elastomer according to any one of Items 38 to 61, wherein the molar ratio of PDI to polyol is at least 1.1:1, preferably from 1.1:1 to 10:1, more preferably from 1.5:1 to 4:1, and even more preferably from 2:1 to 3:1.

[0173] Item 63. The PDI-based elastomer according to any one of Items 38 to 62, wherein the hardness exhibited by the PDI-based elastomer is higher than that of an isophorone diisocyanate-based elastomer (IPDI-based elastomer), and the resilience exhibited by the PDI-based elastomer is higher than that of the IPDI-based elastomer, wherein the IPDI-based elastomer is prepared using the same polyol, the same curing agent, and in the same molar ratio and under the same conditions as the PDI-based elastomer.

[0174] Item 64. The PDI-based elastomer according to Item 63, wherein the resilience of the PDI-based elastomer is at least 1.2 times that of the IPDI-based elastomer.

[0175] Item 65. The PDI-based elastomer according to any one of Items 38 to 64, wherein the tensile strength at break exhibited by the PDI-based elastomer at room temperature is higher than that of the IPDI-based elastomer at room temperature, and the elongation at break exhibited by the PDI-based elastomer at room temperature is higher than that of the IPDI-based elastomer at room temperature, wherein the IPDI-based elastomer is prepared using the same polyol, the same curing agent, and in the same molar ratio and conditions as the PDI-based elastomer.

[0176] Item 66. The PDI-based elastomer according to Item 65, wherein the tensile strength at break of the PDI-based elastomer at room temperature is at least 1.8 times that of the IPDI-based elastomer at room temperature.

[0177] Item 67. The PDI-based elastomer according to any one of Items 38 to 66, wherein the abrasion resistance exhibited by the PDI-based elastomer is higher than that of the IPDI-based elastomer, wherein the IPDI-based elastomer is prepared using the same polyol, the same curing agent, and in the same molar ratio and conditions as the PDI-based elastomer.

[0178] Item 68. The PDI-based elastomer according to any one of Items 38 to 67, wherein the PDI-based elastomer exhibits a higher tear strength than the IPDI-based elastomer, and wherein the IPDI-based elastomer is prepared using the same polyol, the same curing agent as the PDI-based elastomer, and in the same molar ratio and conditions.

[0179] Item 69. The PDI-based elastomer according to any one of Items 38 to 68, wherein the PDI has a bio-based content of at least 71%.

[0180] Item 70. Use of the PDI-based elastomer according to any one of Items 38 to 69 for the production of footwear (e.g., soles), linings, metal coatings, pump seals, wiper blades, snow plow blades, valves, wheels, tires, agitator blades, rollers, rolls, gaskets, seals, pulleys, bumpers, shock absorbers, bushings, bearings, wear strips, skateboards, machine parts, housings, escalator parts, couplings, clamping blocks, grommets, hammers, impact pads, wood sorting pads, gears or sprockets.

[0181] Item 71. The bio-based TPU according to any one of Items 1 to 36, the PDI-based elastomer according to any one of Items 38 to 69, or the use according to Item 37 or 70, wherein the PDI is obtained by a method comprising:

[0182] Subjecting a solution containing cadaverine salt dissolved in an inert solvent in the presence of a tertiary amine base to a liquid-phase phosgenation reaction using a light gas source to convert the cadaverine into PDI,

[0183] wherein the phosgenation reaction comprises the step of maintaining the reaction in a temperature range between 100 °C and 120 °C for a sufficient time to achieve a desired PDI threshold yield,

[0184] wherein the amount of the tertiary amine base present causes the phosgenation reaction to proceed to completion in the temperature range.

[0185] Item 72. The bio-based TPU, PDI-based elastomer, or use according to Item 71, wherein the sufficient time is at least 1.5 hours.

[0186] Item 73. The bio-based TPU, PDI-based elastomer, or use according to Item 71 or 72, wherein the phosgenation reaction is a multi-stage phosgenation reaction, and the multi-stage phosgenation reaction at least includes: a first stage, wherein the solution is heated to a first temperature such that the cadaverine reacts with phosgene from the phosgene source to produce a dichlorocarbamate intermediate, and a subsequent second stage, wherein the solution is further heated to a second temperature higher than the first temperature to subject the dichlorocarbamate intermediate to dehydrochlorination, and the second stage includes the following steps: maintaining the reaction at a temperature between 100 °C and 120 °C for a sufficient time to achieve the PDI threshold yield.

[0187] Item 74. The bio-based TPU, PDI-based elastomer, or use according to Item 73, wherein the first temperature is from about 30 to about 65 °C.

[0188] Item 75. The bio-based TPU, PDI-based elastomer, or use according to Item 73 or 74, wherein the first stage includes maintaining the solution at the first temperature for at least 0.5 hours.

[0189] Item 76. The bio-based TPU, PDI-based elastomer, or use according to any one of Items 73 to 75, wherein the second temperature is at least 10 °C higher than the first temperature.

[0190] Item 77. The bio-based TPU, PDI-based elastomer, or use according to any one of Items 71 to 76, wherein the method uses 3 to 30 moles of phosgene / mole of cadaverine salt.

[0191] Item 78. The bio-based TPU, PDI-based elastomer, or use according to any one of Items 71 to 77, wherein the method uses at least 4 moles of tertiary amine base / mole of cadaverine salt.

[0192] Item 79. The bio-based TPU, PDI-based elastomer, or use according to any one of Items 71 to 78, wherein the cadaverine salt is obtained by fermentation and / or enzymatic conversion, and the content of 2,3,4,5-tetrahydropyridine (THP) or other cyclic by-product impurities in the cadaverine salt is less than 0.1 wt%.

[0193] Item 80. The bio-based TPU, PDI-based elastomer, or use according to any one of Items 71 to 79, wherein the cadaverine salt is cadaverine dihydrochloride.

[0194] Item 81. The biobased TPU, PDI-based elastomer, or use according to any one of Items 71 to 80, wherein the photo gas source is triphosgene, and the tertiary amine base reacts with the triphosgene to release phosgene for the phosgenation reaction.

[0195] Item 82. The biobased TPU, PDI-based elastomer, or use according to any one of Items 71 to 81, wherein the tertiary amine base is a heterocyclic amine or a tertiary amine base having an sp 2 -hybridized N atom.

[0196] Item 83. The biobased TPU, PDI-based elastomer, or use according to any one of Items 71 to 82, wherein the tertiary amine base is pyridine.

[0197] Item 84. The biobased TPU, PDI-based elastomer, or use according to any one of Items 71 to 83, wherein the inert solvent comprises chlorobenzene, dichlorobenzene, toluene, nitrobenzene, or any mixture thereof or consists of the same.

[0198] Item 85. The biobased TPU, PDI-based elastomer, or use according to any one of Items 71 to 84, wherein the inert solvent is a solvent or solvent mixture having a boiling point of at least 120 °C.

[0199] Item 86. The biobased TPU, PDI-based elastomer, or use according to any one of Items 71 to 85, wherein the produced PDI has a THP or other cyclic byproduct impurity content of less than 0.1 wt% before undergoing one or more distillation steps.

[0200] Item 87. The biobased TPU, PDI-based elastomer, or use according to any one of Items 71 to 86, wherein the desired PDI threshold yield is at least 50%.

[0201] Example

[0202] Example 1: Thermoplastic Polyurethane Based on PDI

[0203] Prepare thermoplastic polyurethane (TPU) from biobased PDI and polyether polyol or polyester polyol and characterize its physicochemical properties. Test different polyols and chain extenders.

[0204] Example 1.1: Preparation and Properties

[0205] Materials and Methods

[0206] Chemicals

[0207] The chemicals used in this study are listed in Table 1. As needed, PO3G polyether polyols with 1000 and 2000 MW, PDO-sebacate polyester polyols with 1000 and 2000 MW, and PDO were dried at 75 °C - 80 °C under a vacuum of 1 - 3 mmHg and continuously mixed by a magnetic stirrer to reduce the water content to ≤0.06 wt.%. The water content was confirmed by a Karl Fisher titrator (ASTM D 4672).

[0208] PDI was used as received. Before use, the isocyanate content can be checked by the dibutylamine titration method (ASTM D - 5155).

[0209]

[0210] Preparation of NCO-Prepolymer

[0211] NCO - terminated prepolymers were prepared from PDI diisocyanate and the relevant polyols at an NCO / OH equivalent ratio of approximately 2 / 1 (Table 2). The synthesis of the prepolymers was completed in a 1 L glass reactor equipped with an overhead stirrer, nitrogen purge, and temperature - controlled heating mantle. When the temperature of the isocyanate reached 75 °C, the polyol was added slowly while maintaining the temperature ≤80 °C. The reaction was monitored by measuring the NCO% concentration according to ASTM D5155. When the theoretical NCO% was nearly reached, the reaction mixture was cooled. The prepolymers can be stored in sealed glass containers under nitrogen at room temperature.

[0212] The formulations of the NCO - prepolymers based on PDI and PDO - sebacate polyester polyols with 1000 and 2000 MW and PO3G polyether polyols with 1000 and 2000 MW are summarized in Table 2. The renewable content of each NCO - prepolymer is presented along with the viscosity and melt transition.

[0213]

[0214]

[0215] Preparation and Testing of TPU

[0216] TPU was prepared by reacting the PDI NCO - terminated prepolymer with the sustainable Susterra TM 1,3 - PDO chain extender at an isocyanate index of 1.02 (Tables 3 and 4).

[0217] The NCO-prepolymer preheated at 80 °C and the dry 1,3-PDO chain extender and catalyst were weighed into a cup and mixed using a multi-axis mixer (Speed Mixer, Flack Tek Inc.) at 2200 rpm for 45 seconds. After that, the mixture was transferred to an aluminum mold covered with a Teflon TM sheet preheated at 120 °C. At the gel time, the mold was closed and the TPU was cured at 120 °C for 2 hours. After that, the sample was post-cured at 100 °C for 16 hours in an air-circulation oven.

[0218] After post-curing, the sample was aged for 7 days under room conditions and then tested. The TPU was analyzed by FTIR to confirm the absence of unreacted isocyanate related to the signal at 2270 cm -1 −1.

[0219] The following is a list of tests conducted on the aged TPU samples.

[0220] · Hardness at room temperature, ASTM D-2240, Shore A and Shore D

[0221] · Resilience (Bashore resilience), ASTM D2632 (Bashore resilience tester)

[0222] · Tensile stress-strain properties (tensile strength, elongation at break, modulus, tensile permanent deformation, toughness), ASTM D412 (Instron TM 5500R, model 1122)

[0223] · Heat resistance: Tensile strength up to 400% elongation at 50 °C, ASTM D412 (Instron TM 5500R, model 1122, with heating chamber)

[0224] · Tear strength - Graves die C, ASTM D624 (Instron TM 5500R, model 1122)

[0225] · Compressive strength, ASTM D 695

[0226] · Compressive permanent deformation at 70 °C, ASTM D-395

[0227] · Hydrolysis resistance, stress-strain properties after hydrolysis aging at 50 °C, 5 days, 95% relative humidity

[0228] · Solvent resistance, weight change after soaking in various solvents (water, IPA, oil, MEK) for 3 days

[0229] · Chemical characterization, FTIR analysis: FTIR spectrometer (Spectrum II, Perkin Elmer with Pike Miracle ATR accessory)

[0230] · Thermal properties, differential scanning calorimetry (DSC)

[0231] · Thermal properties, dynamic mechanical analysis (DMA).

[0232] Results and Discussion

[0233] NCO Prepolymer

[0234] NCO-prepolymers were prepared using PDI isocyanate with PO3G 1000, PO3G 2000, PDO-sebacate 1000, and PDO-sebacate 2000 at an isocyanate to polyol equivalent ratio of 2 / 1. The basic parameters in the prepolymer formulations and synthesis are presented in Table 2. No catalyst was added in the PDI NCO-prepolymer synthesis. The isocyanate content of all the prepolymers obtained was close to the theoretical value.

[0235] The viscosity of the PDI prepolymers based on PO3G polyether polyols was significantly lower than that of the PDI prepolymers based on PDO-sebacate polyols. However, the viscosity of the NCO-prepolymers at 70 °C was relatively low, which facilitated processing (Table 2).

[0236] DSC analysis of the PDI prepolymers based on PDO-sebacate polyester polyols with 1000 and 2000 MW showed crystalline melt transitions at 50 °C and 57 °C, respectively (Table 2). DSC analysis of the PDI prepolymers based on PO3G 1000 and 2000 MW showed crystalline melt transitions at 10 °C and 18 °C, respectively (Table 2). As a result, the PDI prepolymers based on PO3G polyether polyols were liquid at room temperature, while the PDI prepolymers based on PDO-sebacate polyols were solid.

[0237] Thermoplastic Polyurethane

[0238] TPU was prepared by reacting the PDI prepolymer with 1,3-PDO chain extender at an isocyanate index of 1.02 under the same conditions (Tables 3 and 4). A small amount of tin catalyst was used in the formulation to facilitate the polymerization, which is typically required for aliphatic isocyanate-based TPU.

[0239] The TPU produced from the PDI prepolymer had a very high renewable content, ranging from 93 wt.% to 96 wt.%.

[0240] TPUs based on PDI prepolymers made from 1000 MW PO3G or PDO-sebacate polyols have 28% hard segments, while TPUs made from 2000 MW PO3G or PDO-sebacate polyols have approximately 16% hard segments. The hard segment values are relatively low compared to conventional diisocyanates (e.g., 4,4'-MDI) prepared with the same equivalent ratio of isocyanate / polyol / chain extender. The low hard segments can be attributed to the fact that PDI has the lowest molecular weight of currently commercially available diisocyanates. However, if desired, the hard segment concentration in the TPU can be increased by generating a higher NCO prepolymer from PDI, which would require a higher concentration of chain extender in the synthesis of the TPU.

[0241] FTIR analysis of the TPU showed no significant absorption associated with free NCO groups at 2270 cm -1 −1, indicating completion of the polyurethane polymerization.

[0242] The total TPUs made from PDI prepolymers based on PDO-sebacate polyols appear to be stronger and more uniform than the corresponding TPUs made from PDI prepolymers based on PO3G polyols with the same hard segment concentration. Generally, TPUs based on polyester polyols are stronger than TPUs based on polyether polyols. The PDI TPUs based on PO3G polyols can be further optimized by potentially selecting different chain extenders (e.g., BDO, HQEE, cyclohexanedimethanol (CHDM)). It is expected that TPUs generated by a one-step reaction between PDI, polyol, and chain extender will have similar properties.

[0243] The PDI TPUs based on 1000 MW polyols (both polyester and polyether) exhibit relatively high resilience. The PDI TPUs based on 2000 MW polyols exhibit lower crystallinity because of the higher crystallinity of the soft segments, which reduces the dynamic properties (Table 5). The physical and mechanical properties of the TPUs are presented in Tables 5A and 5B.

[0244] DSC analysis of the TPU made from the PDI prepolymer based on 1000 MW PDO-sebacate polyol showed a low level of crystallinity and a melt transition at 28 °C (Table 5A), which was significantly attenuated compared to the corresponding prepolymer. The TPU made from the PDI prepolymer based on 2000 MW PDO-sebacate polyol showed a higher level of crystallinity and a melt transition at 47 °C (Table 5A).

[0245] On the other hand, the TPU produced from the PDI prepolymer based on 1000 MW PO3G polyol did not show crystallinity associated with the soft segments. The TPU produced from the PDI prepolymer based on 2000 MW PO3G polyol showed notable crystalline domains, however, with a low melt transition temperature, around 14 °C (Table 5A). DMA analysis also showed that the TPU based on PDI and PDO-sebacate polyol had a higher melt transition than the corresponding TPU based on PO3G polyol.

[0246] The following is a summary of the key physical and mechanical properties of the TPU presented in Tables 5A and 5B:

[0247] · The TPU based on PDI prepolymer (based on PDO-sebacate polyester polyol) exhibited higher hardness than the TPU based on PO3G polyether polyol. TPU based on polyester polyol typically has higher hardness.

[0248] · The PDI TPU with a higher hard segment content (i.e., based on PO3G polyol) had higher hardness, which is typically the case for polyol-based TPU. However, compared to the PDI TPU based on 1000 MW PDO-sebacate, the crystallinity of the PDI TPU based on 2000 MW PDO-sebacate was associated with the enhanced hardness of the TPU.

[0249] · The tensile strength and modulus of the polyester TPU based on PDO-sebacate polyol were higher than those of the polyether TPU, which is typically the case when comparing polyester-based TPU with polyether-based TPU. The PDI TPU based on PDO-sebacate polyol also had high toughness, as determined by the area under the tensile stress-strain curve. This should translate into good abrasion resistance for these PDI TPU.

[0250] · The tear strength of the PDI TPU based on PDO-sebacate polyol was higher compared to the PDI TPU based on PO3G polyol, which may be related to its excellent tensile properties.

[0251] · The compressive strength and modulus of the polyester TPU based on PDO-sebacate polyol were higher than those of the polyether TPU.

[0252] · The compression set (permanent deformation) of the PDI TPU based on PDO-sebacate polyol was also lower compared to the compression set (permanent deformation) of the PDI TPU based on PO3G polyol.

[0253] · The heat resistance of PDI TPU was measured as the retention rate of the tensile properties at 50 °C (Table 5B). For the retention rate of the tensile modulus of PDI TPU, those based on 2000MW were lower compared to those based on 1000MW PDO-sebacate polyol.

[0254] · All PDI TPUs showed excellent retention rates during hydrolysis aging (Table 5B). This is particularly important for the evaluated polyester TPUs, which are generally more susceptible to moisture than polyether TPUs. This may be attributed to the good hydrolysis resistance of PDO-sebacate polyester polyol.

[0255] · All PDI TPUs showed comparable water and oil resistance. However, interestingly, PDI TPUs based on PDO-sebacate polyester polyol actually had lower water absorption than PDI TPUs based on PO3G polyether polyol. In addition, PDI TPUs based on PDO-sebacate polyester polyol had higher polar and non-polar solvent resistance than PDI TPUs based on PO3G polyol of the corresponding molecular weight.

[0256]

[0257]

[0258]

[0259]

[0260] Example 1.2: Preparation of Another PDI-Based TPU Prepared with PTMEG 1000 and BDO Adipate 1000 Polyols Preparation

[0261] Materials and Methods

[0262] Chemicals

[0263] The chemicals used in this example are listed in Table 6.

[0264] Before use, PTMEG 1000, BDO adipate 1000, and 1,4-butanediol (BDO) were dried at 75 °C - 80 °C under a vacuum of 1 - 3 mmHg and continuously mixed by a magnetic stirrer for 24 hours. The water content of the polyol used to prepare the NCO-prepolymer was ≤ 0.06 wt.%. The water content after drying was checked by a Karl Fisher titrator.

[0265] The isocyanate was used as received from the supplier. Before use, the isocyanate content was checked by di-n-butylamine titration.

[0266]

[0267] NCO-Prepolymer

[0268] An NCO-terminated prepolymer is produced from PDI diisocyanate with PTMEG 1000 and BDO-adipate 1000 polyol at an NCO / OH equivalent ratio of about 2 / 1. The synthesis of the prepolymer is completed in a 1 L glass reactor equipped with an overhead stirrer, nitrogen purge, and temperature-controlled heating mantle. When the temperature of the isocyanate reaches 75 °C, the polyol is added slowly while maintaining the temperature ≤80 °C. The reaction is monitored by measuring the NCO% concentration according to ASTM D5155. When the approximate theoretical NCO% is reached, the reaction mixture is cooled. The prepolymer can be stored in a sealed glass container under nitrogen at room temperature.

[0269] Formulations of NCO-prepolymers based on PDI with PTMEG 1000 polyether polyol are summarized in Table 7A. Formulations of NCO-prepolymers based on PDI with BDO-adipate 1000 polyester polyol are summarized in Table 7B.

[0270] Preparation and Testing of TPU

[0271] TPU is prepared by reacting the PDI NCO-terminated prepolymer with 1,4-BDO chain extender at an isocyanate index of 1.02. The NCO-prepolymer preheated at 80 °C and dry BDO chain extender and catalyst are weighed into a cup and mixed using a multi-axis mixer (Speed Mixer, Flack Tek Inc.) at 2200 rpm for 45 seconds. Thereafter, the mixture is transferred to an aluminum mold covered with a Teflon TM sheet preheated at 120 °C. At the gel time, the mold is closed and the TPU is cured at 120 °C for 2 hours. Thereafter, the sample is post-cured at 100 °C for 16 hours in an air-circulating oven.

[0272] After post-curing, the sample is aged for 7 days under room conditions and then tested. The tests conducted on the aged sample are the same as those conducted in Example 1.1.

[0273] Results and Discussion

[0274] NCO Prepolymer

[0275] An NCO-prepolymer was prepared using PDI isocyanate with PTMEG 1000 and BDO-adipate 1000 polyols at an isocyanate to polyol equivalent ratio of 2 / 1. The basic parameters in the prepolymer formulation and synthesis are presented in Tables 7A and 7B. The isocyanate content of all the prepolymers obtained was close to the theoretical value. The viscosity of the NCO-prepolymers at 70 °C was relatively low, which facilitated processing (Tables 7A and 7B). The PDI / PTMEG1000 prepolymer was liquid at room temperature. The PDI / BDO-adipate 1000 prepolymer was solid at room temperature.

[0276] DSC analysis of the PDI prepolymer based on BDO-adipate 1000 polyester polyol showed crystallinity associated with the soft polyol segments at about 45 °C. The PDI / PTMEG 1000 prepolymer had a crystallization transition at 13 °C.

[0277] Thermoplastic Polyurethane

[0278] TPUs based on PDI isocyanate prepolymers were prepared under the same conditions (Table 8). A small amount of tin catalyst was used in the formulation.

[0279] All the TPUs were essentially transparent at room temperature, indicating low crystallinity.

[0280] FTIR analysis of the TPUs showed no significant absorption associated with free NCO groups at 2270 cm -1 −1, indicating completion of the polyurethane polymerization.

[0281] Analysis of the TPUs by DSC showed no crystallization associated with the soft polyol segments. As expected, the glass transition temperature of the TPU based on polyether PTMEG 1000 was lower than that of the TPU based on polyester BDO adipate 1000.

[0282] The following is a summary of the key physical and mechanical properties of the TPUs presented in Tables 9A and 9B:

[0283] · All the TPUs exhibited low compression set, which is a desirable property for TPUs.

[0284] · The PDI-based TPUs had high resilience. High resilience may be a desirable property requirement in many TPU and elastomer applications.

[0285] · The tensile strength of the polyester TPUs was higher than that of the polyether TPUs, as expected.

[0286] · For all the TPUs, the elasticity, as measured by elongation at break, was very high.

[0287] · The heat resistance of TPU was measured as the retention rate of the tensile properties at 50 °C (Table 9B). The heat retention rate of polyether TPU was slightly lower than that of polyester TPU. As expected, the tensile strength decreased at 50 °C compared to room temperature.

[0288] · All TPUs showed excellent property retention rates during hydrolysis aging (Table 9B). This is especially important for polyester TPU, which is generally more susceptible to moisture than polyether TPU.

[0289]

[0290]

[0291]

[0292]

[0293]

[0294]

[0295]

[0296] Example 1.3: Preparation and Properties of PDI-Based TPU Prepared with PDO Sebacate 2000 as Polyol and Two Different Chain Extenders Preparation and Properties of TPU

[0297] Materials and Methods

[0298] TPU was prepared by bulk polymerization of a prepolymer (or quasi-prepolymer) and a chain extender using a compression molding method. An NCO-terminated prepolymer was prepared from PDI diisocyanate and the relevant polyol in the required NCO / OH equivalent ratio.

[0299] Chemicals

[0300] The materials used are summarized in Table 10.

[0301]

[0302]

[0303] NCO Prepolymer

[0304] Prepare a prepolymer and two quasi-prepolymers (Table 11) based on PDO sebacate 2000. Measure the isocyanate content (NCO%) of the prepolymer and quasi-prepolymers. The synthesis of the prepolymer was carried out in a 1-L glass reactor equipped with an overhead stirrer, nitrogen purge, and temperature-controlled heating mantle according to the following procedure: Place the calculated amount of isocyanate in a 1-L glass reaction kettle equipped with a stirrer shaft and a continuous nitrogen stream. Heat the reactor with a temperature-controlled heating jacket. When the temperature of the isocyanate reaches 70 °C, add the polyol to the reactor while maintaining continuous stirring and keeping the temperature below 90 °C. Monitor the reaction by NCO% titration. After reaching the theoretical NCO%, stop the reaction by cooling to room temperature. The prepolymer was stored in a sealed glass bottle under nitrogen at room temperature.

[0305]

[0306] Thermoplastic Polyurethane

[0307] Preheat the NCO-prepolymer prepared as in Table 11 at 80 °C, and weigh the dry chain extender and catalyst into a cup, and mix them for 45 seconds at 2200 rpm using a multi-axis mixer (Speed Mixer, Flack Tek Inc.). After that, transfer the mixture to an aluminum mold covered with a Teflon sheet preheated at 120 °C. TM At the gel time, close the mold, and cure the TPU at 120 °C for 2 hours. After that, post-cure the sample in an air-circulating oven at 100 °C for 16 hours. After post-curing, age the sample for 7 days under room conditions and then test. Analyze the TPU by FTIR to confirm the absence of unreacted isocyanate related to the signal at 2270 cm -1 . For each type of TPU, prepare test sheets and button samples as needed for various tests according to ASTM methods. A summary of the conditions and amounts of the products used to prepare the TPU is shown in Table 12A. The properties of the TPU are reported in Table 12B.

[0308]

[0309]

[0310]

[0311]

[0312] The data reported in the first two columns of Table 12A and Table 12B (PDI / BDO / SBA_2 / 1 / 1 and PDI / PDO / SBA_2 / 1 / 1) show the effect of using BDO and PDO as chain extenders on the properties of TPU. It can be observed that PDO produces PDI-TPU with higher hardness and tensile strength compared to BDO-based PDI-TPU, despite a lower hard segment concentration. In addition, PDO produces PDI-TPU with higher resilience, tensile strength, elongation at break, and lower compression set. The behavior observed when using a chain extender with an odd number of methylene groups (i.e., 1,3-PDO) may be due to a conformation that is more favorable for hydrogen bonding of the urethane groups, resulting in a higher level of urethane bonding in the hard segments.

[0313] Table 12A and Table 12B also show that when using a higher level of BDO chain extender, this may result in a higher hard segment concentration in the TPU (see the data in columns 1, 3, and 4).

[0314] Example 2 : Based on PDI Polyurethane Elastomer

[0315] Prepare polyurethane cast elastomers from bio-based PDI and polyether polyols or polyester polyols. In addition, compare the properties of the bio-based PDI isocyanate with commercial IPDI aliphatic isocyanates in polyurethane cast elastomers based on polyether polyols and polyester polyols.

[0316] Materials and Methods

[0317] Prepare cast elastomers from PDI and IPDI aliphatic isocyanate NCO-prepolymers, which are cured with Ethacure TM 300 sterically hindered diamine.

[0318] Prepare cast elastomers using the following aliphatic NCO-prepolymers:

[0319] · PDI with a PTMG 1000 / PTMG 650 (50 / 50) blend

[0320] · PDI with PDO sebacate 2000

[0321] · IPDI (control) with a PTMG 1000 / PTMG 650 (50 / 50) blend

[0322] · IPDI (control) with PDO sebacate 2000.

[0323] Then react the NCO-prepolymers with Ethacure TM300 reaction to prepare cast elastomers:

[0324] · PDI / PTMG 1000 / PTMG 650(50 / 50) / Ethacure TM 300

[0325] · PDI / PDO sebacate 2000 / Ethacure TM 300

[0326] · IPDI / PTMG 1000 / PTMG 650(50 / 50) / Ethacure TM 300 (control)

[0327] · IPDI / PDO sebacate 2000 / Ethacure TM 300 (control).

[0328] Table 13 below summarizes the information of the reactants used in the experiment.

[0329]

[0330] Preparation of NCO-Prepolymer

[0331] NCO-terminated prepolymers, based on aliphatic isocyanates and polyols, were prepared at an NCO / OH equivalent ratio of 2 / 1 according to the following procedure: The calculated amount of isocyanate was placed in a 1-L glass reactor equipped with a stirring shaft and a continuous nitrogen stream. The reactor was heated with a temperature-controlled heating jacket. When the temperature of the isocyanate reached 70 °C, the polyol was added to the reactor while maintaining continuous stirring and keeping the temperature below 90 °C. The reaction was monitored by NCO% titration. After reaching the theoretical NCO%, the reaction was stopped by cooling to room temperature. The prepolymers were stored in sealed glass bottles under nitrogen at room temperature.

[0332] Measure the following properties of the TDI NCO-prepolymers:

[0333] · Obtain NCO% through the TPI-internal procedure based on TSI

[0334] · Obtain the viscosity at 70 °C according to ASTM D-4878 using a Brookfield viscometer

[0335] · Obtain the thermal properties by DSC.

[0336] Preparation of Cast Elastomer

[0337] By reacting the NCO-prepolymer with Ethacure TMThe 300 reaction was carried out at an equivalent ratio of 1.05 to 1 to prepare the cast elastomer. The calculated amount of prepolymer was weighed into a 100 g cup (suitable for Speed Mixer) and heated in an oven at 80 °C for 1 hour. The calculated amount of Ethacure TM 300 was added to the prepolymer and mixed for one minute by a planetary mixer (Speed Mixer, FlackTek TM Inc.). At the gel time, the mixture was transferred to an aluminum mold covered with a Teflon TM sheet preheated to 80 °C. The mold was placed in a hydraulic press and the resin was compression molded at about 20,000 psi for 60 minutes.

[0338] Cast elastomer sheets (6 x 6 inches and 3 mm thickness) and cylindrical samples "buttons" (D = 1 in, H = 1 / 2 in) were fabricated for testing. The samples were aged at room temperature for seven days before testing.

[0339] Testing of Cast Elastomer

[0340] The following properties of the cast elastomer were measured:

[0341] · Hardness, Shore A, ASTM D-2240

[0342] · Tensile stress-strain properties at room temperature, ASTM-412 (tensile strength at break, 100% and 300% modulus, elongation at break)

[0343] · Tear resistance, Graves die C, ASTM D-624

[0344] · Resilience, Ball Shore rebound resilience, ASTM D 430

[0345] · Heat resistance (tensile properties at 50 °C and 70 °C)

[0346] · Hydrolytic stability (weight change and change in stress-strain properties upon exposure to 100% RH at 60 °C for 5 days). The retention rate of the tensile properties was calculated.

[0347] · Abrasion resistance, ASTM D 1044

[0348] · Oil resistance in selected hydraulic oils (weight change after soaking at room temperature for three days)

[0349] · Tolerance in aqueous solutions (above pH 7 and below pH 7) (weight change after soaking at room temperature for three days).

[0350] · Glass transition temperature (T g ) obtained by DSC.

[0351] Adhesion Testing of Cast Elastomer

[0352] Prepare adhesion test specimens using a steel panel RS-14 (Q-Lab Corporation) with a (3 in. x 1 in. size) substrate. The steel panel was pretreated with a primer used to enhance the adhesion between the cast elastomer and steel, which is a common practice in the production of protective urethane linings for pipe protection.

[0353] Mix the NCO-prepolymer and the curing agent Ethacure TM 300 in the specified weight ratio, depending on the formulation passed through a planetary mixer. Place the mixed resin in an oven at 60 °C to thicken. Spread approximately 0.15 g of the resin onto the end (0.5 in.) of each steel plate. Clamp the two plates together with an overlap of 0.5 in. Cure the samples in the oven at 60 °C for 1 hour. Before testing, age the samples at room temperature for three days.

[0354] Test the adhesion properties by ASTM D1002 adhesion lap shear test.

[0355] Also subject the adhesion samples to wet aging (95% RH at 60 °C for 5 days) and test them after aging.

[0356] Results and Discussion

[0357] The results are summarized in Tables 14 to 20 below.

[0358]

[0359]

[0360]

[0361] *PP = prepolymer

[0362] **Average temperature during synthesis (highest temperature reached in parentheses)

[0363]

[0364]

[0365]

[0366]

[0367]

[0368]

[0369] It can be observed from the results reported above that:

[0370] · The NCO-prepolymer with the expected NCO% was prepared using a conventional method for preparing NCO-prepolymers (Table 15). The prepolymer based on PDI isocyanate exhibits a viscosity significantly lower than that of the prepolymer based on IPDI isocyanate, which may be beneficial in cast elastomer applications. In the preparation of cast elastomers, the NCO-prepolymer based on PDI shows slightly higher reactivity, which is reflected by a faster gel time (Table 16).

[0371] The glass transition temperature of the PDI cast elastomer is lower than that of the IPDI cast elastomer, which may indicate better phase separation of the hard and soft segments (Table 17). The reduced glass transition of the cast elastomer can be used for low-temperature applications.

[0372] · The cast elastomer based on PDI isocyanate exhibits higher hardness and higher resilience than the one based on IPDI, which is an interesting combination of properties (Table 18). The hard segment concentration in the PDI-based cast elastomer is lower than that in the IPDI-based one, which would typically result in lower hardness. However, the improved hardness is most likely due to a more ordered morphology and better hard segment phase separation in the PDI-based cast elastomer compared to IPDI.

[0373] · The PDI-based cast elastomer exhibits higher tensile strength at break, tensile modulus at 100%, and elongation at break compared to the corresponding IPDI-based cast elastomer (Table 17). As a result, the PDI-based cast elastomer exhibits higher toughness (measured as the area under the tensile curve). The toughness of the elastomer is very important in applications where the material is exposed to dynamic stress.

[0374] · The tear strength of the PDI-based cast elastomer is higher than that of the corresponding IPDI-based cast elastomer, which may be related to the improved toughness (Table 17).

[0375] · The abrasion resistance of the PDI-based cast elastomer is much better compared to the corresponding IPDI-based cast elastomer (Table 17). The abrasion resistance of the polyester PDI elastomer (measured as weight loss in a Taber abrasion tester) is approximately twice that of the corresponding polyester IPDI elastomer. In the case of PTMG-based cast elastomers, PDI produces a cast elastomer with significantly lower Taber weight loss compared to the IPDI-based cast elastomer. Abrasion resistance is a key property of cast elastomers in many applications that require low wear.

[0376] · Compared with IPDI / PTMG cast elastomers, the heat resistance and moisture resistance of PDI / PTMG cast elastomers are much better (Table 17). The retention rate of the tensile modulus of PDI-based elastomers with temperature is much better. The retention rate of the tensile modulus after wet-temperature aging of PDI-based cast elastomers is much better.

[0377] · Solvent resistance was measured by determining the weight gain after immersion in hydraulic oil and acidic and alkaline water media (Table 17). The weight gain of PDI-based cast elastomers is slightly higher compared to IPDI-based cast elastomers.

[0378] · PDI cast elastomers exhibit much better adhesion to metals than IPDI cast elastomers (Table 20). PDI cast elastomers also exhibit stronger adhesion to metals after wet aging.

Claims

1. A bio-based thermoplastic polyurethane obtained from the bio-based monomers pentamethylene diisocyanate (PDI), at least one polyol, in the presence of at least one hydroxyl-functional chain extender, wherein the polyol is optionally bio-based and is a polyester diol, wherein the PDI has a bio-based content of at least 70%, and wherein PDI is used as the sole isocyanate, wherein the molar ratio of PDI to polyol to chain extender is from 2:1:1 to 3:1:1, wherein the bio-based thermoplastic polyurethane has a bio-based content of 93% to 100%, and wherein the bio-based thermoplastic polyurethane has a hard segment content ranging from 10 wt% to 40 wt%.

2. The bio-based thermoplastic polyurethane according to claim 1, wherein the polyester diol comprises a succinate-based polyester diol, an adipate-based polyester diol, a sebacate-based polyester diol, a azelate-based polyester diol, an 1,18-octadecanedioic acid-based polyester diol, or any combination thereof.

3. The bio-based thermoplastic polyurethane according to claim 1, wherein the polyester diol is synthesized from an organic diacid selected from succinic acid, adipic acid, sebacic acid, azelaic acid, 1,18-octadecanedioic acid, and any combination thereof, and a diol selected from 1,4-butanediol, 1,3-propanediol, and mixtures thereof.

4. The bio-based thermoplastic polyurethane according to claim 1, wherein the polyester diol is selected from 1,4-butanediol adipate, 1,3-propanediol adipate, 1,4-butanediol sebacate, 1,3-propanediol sebacate, and any combination thereof.

5. The bio-based thermoplastic polyurethane according to claim 1, wherein the polyester diol is bio-based 1,3-propanediol sebacate.

6. The bio-based thermoplastic polyurethane according to any one of claims 1 to 5, wherein the polyester diol is bio-based and has a bio-based content of at least 99%.

7. The bio-based thermoplastic polyurethane according to any one of claims 1 to 5, wherein the polyol has a molecular weight of at least 500 g / mol.

8. The bio-based thermoplastic polyurethane according to any one of claims 1 to 5, wherein the polyol has a molecular weight ranging from 500 to 10,000 g / mol.

9. The bio-based thermoplastic polyurethane according to any one of claims 1 to 5, wherein the polyol has a molecular weight ranging from 500 to 3,000 g / mol.

10. The bio-based thermoplastic polyurethane according to any one of claims 1 to 5, wherein the chain extender is selected from butanediol, pentanediol, hexanediol, ethylene glycol, propylene glycol, hydroquinone bis(2-hydroxyethyl) ether (HQEE), 1,3-bis(2-hydroxyethyl) resorcinol (HER), cyclohexanedimethanol (CHDM), 3-methyl-1,5-pentanediol, 2-butyl-2-ethyl-1,3-propanediol, and any combination thereof.

11. The bio-based thermoplastic polyurethane according to any one of claims 1 to 5, wherein the chain extender is a bio-based chain extender.

12. The bio-based thermoplastic polyurethane according to any one of claims 1 to 5, wherein the chain extender is selected from bio-based 1,3-propanediol and bio-based 1,4-butanediol.

13. The bio-based thermoplastic polyurethane according to any one of claims 1 to 5, wherein the chain extender has an odd number of carbon atoms.

14. The bio-based thermoplastic polyurethane according to any one of claims 1 to 5, wherein the chain extender is bio-based 1,3-propanediol.

15. The bio-based thermoplastic polyurethane according to any one of claims 1 to 5, wherein the bio-based thermoplastic polyurethane is obtained by reacting an NCO-terminated prepolymer produced from the bio-based monomer PDI and the at least one polyol with the at least one chain extender.

16. The bio-based thermoplastic polyurethane according to claim 15, wherein the NCO-terminated prepolymer is produced by reacting the PDI and the polyol at a molar ratio of 1.1:1 to 10:1 by heating at a temperature ranging from 50 °C to 120 °C.

17. The bio-based thermoplastic polyurethane according to claim 15, wherein the NCO-terminated prepolymer is produced by reacting the PDI and the bio-based polyol at a molar ratio of at least 2:

1.

18. The bio-based thermoplastic polyurethane according to claim 15, wherein the NCO-terminated prepolymer is produced by mixing the PDI and the bio-based polyol in the absence of any catalyst.

19. The bio-based thermoplastic polyurethane according to claim 15, wherein the NCO-terminated prepolymer is produced using a dehumidified bio-based polyol.

20. The bio-based thermoplastic polyurethane according to claim 19, wherein the dehumidified bio-based polyol has a water content of less than 0.1 wt% based on the weight of the polyol.

21. The bio-based thermoplastic polyurethane according to claim 19, wherein the dehumidified bio-based polyol has a water content of less than 0.06 wt% based on the weight of the polyol.

22. The bio-based thermoplastic polyurethane according to claim 15, wherein the NCO-terminated prepolymer has a bio-based content of at least 90%.

23. The bio-based thermoplastic polyurethane according to claim 15, wherein the NCO-terminated prepolymer has a bio-based content ranging from 90% to 100%.

24. The bio-based thermoplastic polyurethane according to claim 15, wherein the NCO-terminated prepolymer has a viscosity ranging from 100 cps to 10000 cps at 70 °C.

25. The bio-based thermoplastic polyurethane according to claim 15, wherein the NCO-terminated prepolymer has a viscosity ranging from 500 cps to 7000 cps at 70 °C.

26. The bio-based thermoplastic polyurethane according to claim 15, wherein the reaction of the NCO-terminated prepolymer with the chain extender is carried out under heating with or without a catalyst.

27. The bio-based thermoplastic polyurethane according to claim 1, wherein the bio-based thermoplastic polyurethane is obtained from pentamethylene diisocyanate PDI with a bio-based content of at least 70% and a bio-based 1,3-propanediol-sebacate polyester diol with a molecular weight of 1000 g / mol, the chain extender is bio-based 1,3-propanediol, the molar ratio of PDI to the bio-based polyol to the chain extender is 2:1:1, and wherein the bio-based thermoplastic polyurethane has a hard segment content ranging from 20 wt% to 30 wt%.

28. The bio-based thermoplastic polyurethane according to claim 27, wherein the bio-based thermoplastic polyurethane has a hard segment content ranging from 25 wt% to 30 wt%.

29. The bio-based thermoplastic polyurethane according to claim 1, wherein the bio-based thermoplastic polyurethane is obtained from pentamethylene diisocyanate PDI with a bio-based content of at least 70% and a bio-based 1,3-propanediol-sebacate polyester diol with a molecular weight of 2000 g / mol, the chain extender is bio-based 1,3-propanediol, the molar ratio of PDI to the bio-based polyol to the chain extender is 2:1:1, and wherein the bio-based thermoplastic polyurethane has a hard segment content ranging from 10 wt% to 20 wt%.

30. The bio-based thermoplastic polyurethane according to claim 29, wherein the bio-based thermoplastic polyurethane has a hard segment content ranging from 13 wt% to 18 wt%.

31. The bio-based thermoplastic polyurethane according to any one of claims 1 to 5, wherein the bio-based thermoplastic polyurethane is characterized by a tensile stress at break of at least 3000 psi at room temperature.

32. The bio-based thermoplastic polyurethane according to claim 1, wherein the bio-based thermoplastic polyurethane is obtained from pentamethylene diisocyanate PDI with a bio-based content of at least 70% and a bio-based 1,3-propanediol-sebacate polyester diol, the chain extender is bio-based 1,3-propanediol, and wherein the bio-based thermoplastic polyurethane is characterized by a tensile stress at break of at least 3000 psi at room temperature.

33. The bio-based thermoplastic polyurethane according to any one of claims 1 to 5, wherein the PDI has a bio-based content of at least 71%.

34. The bio-based thermoplastic polyurethane according to any one of claims 1 to 5, wherein the PDI is obtained by a method comprising: subjecting a solution containing cadaverine salt dissolved in an inert solvent in the presence of a tertiary amine base to a liquid-phase phosgenation reaction using a light gas source to convert the cadaverine into PDI, wherein the phosgenation reaction comprises the following steps: maintaining the reaction in a temperature range between 100 °C and 120 °C for a sufficient time to achieve a desired PDI threshold yield, wherein the amount of the tertiary amine base present allows the phosgenation reaction to proceed to completion in the temperature range.

35. The bio-based thermoplastic polyurethane according to claim 34, wherein the sufficient time is at least 1.5 hours.

36. The bio-based thermoplastic polyurethane according to claim 34, wherein the phosgenation reaction is a multi-stage phosgenation reaction, and the multi-stage phosgenation reaction at least comprises: a first stage, in which the solution is heated to a first temperature such that the cadaverine reacts with phosgene from the phosgene source to produce a dichlorocarbamoyl chloride intermediate, and a subsequent second stage, in which the solution is further heated to a second temperature higher than the first temperature to subject the dichlorocarbamoyl chloride intermediate to dehydrochlorination, wherein the second stage comprises the step of maintaining the reaction at a temperature between 100 °C and 120 °C for a sufficient time to achieve a PDI threshold yield.

37. The bio-based thermoplastic polyurethane according to claim 36, wherein the first temperature is from 30 to 65 °C.

38. The bio-based thermoplastic polyurethane according to claim 36, wherein the first stage comprises maintaining the solution at the first temperature for at least 0.5 hours.

39. The bio-based thermoplastic polyurethane according to claim 37, wherein the first stage comprises maintaining the solution at the first temperature for at least 0.5 hours.

40. The bio-based thermoplastic polyurethane according to claim 36, wherein the second temperature is at least 10 °C higher than the first temperature.

41. The bio-based thermoplastic polyurethane according to claim 34, wherein the method uses 3 to 30 moles of phosgene per mole of cadaverine salt.

42. The bio-based thermoplastic polyurethane according to claim 34, wherein the method uses at least 4 moles of tertiary amine base per mole of cadaverine salt.

43. The bio-based thermoplastic polyurethane according to claim 34, wherein the cadaverine salt is obtained by fermentation and / or enzymatic conversion, and the content of 2,3,4,5-tetrahydropyridine THP or other cyclic by-product impurities in the cadaverine salt is less than 0.1 wt%.

44. The bio-based thermoplastic polyurethane according to claim 34, wherein the cadaverine salt is cadaverine dihydrochloride.

45. The bio-based thermoplastic polyurethane according to claim 34, wherein the phosgene source is triphosgene, and the tertiary amine base reacts with the triphosgene to release phosgene for the phosgenation reaction.

46. The bio-based thermoplastic polyurethane according to claim 34, wherein the tertiary amine base is a heterocyclic amine or a tertiary amine base having an sp 2 -hybridized N atom.

47. The bio-based thermoplastic polyurethane according to claim 34, wherein the tertiary amine base is pyridine.

48. The bio-based thermoplastic polyurethane according to claim 34, wherein the inert solvent comprises chlorobenzene, dichlorobenzene, toluene, nitrobenzene or any mixture thereof or consists of the same.

49. The bio-based thermoplastic polyurethane according to claim 34, wherein the inert solvent is a solvent or solvent mixture having a boiling point of at least 120 °C.

50. The bio-based thermoplastic polyurethane according to claim 34, wherein the PDI produced has a content of THP or other cyclic by-product impurities of less than 0.1 wt% before undergoing one or more distillation steps.

51. The bio-based thermoplastic polyurethane according to claim 34, wherein the desired PDI threshold yield is at least 50%.

52. The bio-based thermoplastic polyurethane according to claim 15, wherein the NCO-terminated prepolymer has a bio-based content of from 90% to 99%.

53. The bio-based thermoplastic polyurethane according to claim 15, wherein the NCO-terminated prepolymer has a bio-based content of from 90% to 98%.

54. The bio-based thermoplastic polyurethane according to claim 15, wherein the NCO-terminated prepolymer has a bio-based content of from 90% to 97%.

55. The bio-based thermoplastic polyurethane according to claim 15, wherein the NCO-terminated prepolymer has a bio-based content of from 90% to 96%.

56. The bio-based thermoplastic polyurethane according to claim 15, wherein the NCO-terminated prepolymer has a bio-based content of from 90% to 95%.

57. Use of the bio-based thermoplastic polyurethane according to any one of claims 1 to 56 for the production of footwear, pipes, hoses, rollers, wheels, gaskets, seals, hot melt adhesives, expandable thermoplastic polyurethanes, belts, wire coatings, metal coatings, pipe coatings, sieve coatings, laminates, labels, inflatables, textile coatings, clothing, barrier films, sporting goods or medical devices.

58. A PDI-based elastomer obtained from the bio-based monomer pentamethylene diisocyanate PDI and at least one polyol in the presence of at least one curing agent, wherein the PDI has a bio-based content of at least 70%, wherein PDI is the only isocyanate, wherein the polyol is a polyester polyol, and wherein the curing agent is selected from sterically hindered amines, secondary diamines, diamine ether oligomers and any combination thereof; wherein the PDI-based elastomer has a bio-based content of from 90% to 100%.

59. The PDI-based elastomer according to claim 58, wherein the polyester polyol is a succinate-based polyester diol, an adipate-based polyester diol, a sebacate-based polyester diol, a azelate-based polyester diol, an 1,18-octadecanedioic acid-based polyester diol, or any combination thereof.

60. The PDI-based elastomer according to claim 58, wherein the polyester polyol is optionally bio-based and is synthesized from organic diacids selected from succinic acid, adipic acid, sebacic acid, azelaic acid, 1,18-octadecanedioic acid and any combination thereof and diols selected from 1,4-butanediol, 1,3-propanediol and mixtures thereof.

61. The PDI-based elastomer according to claim 59, wherein the polyester polyol is optionally bio-based and is synthesized from organic diacids selected from succinic acid, adipic acid, sebacic acid, azelaic acid, 1,18-octadecanedioic acid and any combination thereof and diols selected from 1,4-butanediol, 1,3-propanediol and mixtures thereof.

62. The PDI-based elastomer according to any one of claims 58 to 61, wherein the polyester polyol is selected from 1,4-butanediol adipate, 1,3-propanediol adipate, 1,4-butanediol sebacate, 1,3-propanediol sebacate, and any combination thereof.

63. The PDI-based elastomer according to any one of claims 58 to 61, wherein the polyester polyol is 1,3-propanediol sebacate.

64. The PDI-based elastomer according to any one of claims 58 to 61, wherein the polyester polyol is a bio-based polyester polyol.

65. The PDI-based elastomer according to any one of claims 58 to 61, wherein the polyester polyol has a bio-based content of at least 99%.

66. The PDI-based elastomer according to any one of claims 58 to 61, wherein the polyol has a molecular weight of at least 500 g / mol.

67. The PDI-based elastomer according to any one of claims 58 to 61, wherein the polyol has a molecular weight in the range of 500 to 10,000 g / mol.

68. The PDI-based elastomer according to any one of claims 58 to 61, wherein the polyol has a molecular weight in the range of 500 to 3,000 g / mol.

69. The PDI-based elastomer according to any one of claims 58 to 61, wherein the curing agent comprises a sterically hindered diamine, and the sterically hindered diamine comprises an aromatic diamine having two primary amino groups or having one primary amino group and one secondary amino group or having two secondary amino groups.

70. The PDI-based elastomer according to any one of claims 58 to 61, wherein the curing agent comprises at least one sterically hindered diamine, including an aromatic diamine.

71. The PDI-based elastomer according to any one of claims 58 to 61, wherein the curing agent comprises dimethylthio-toluenediamine DMTDA, diethyltoluenediamine, 4,4'-methylene-bis(2-chloroaniline) MOCA, or any mixture thereof.

72. The PDI-based elastomer according to claim 71, wherein the diethyltoluenediamine is selected from 3,5-diethyltoluene-2,4-diamine, 3,5-diethyltoluene-2,6-diamine, or a mixture thereof.

73. The PDI-based elastomer according to any one of claims 58 to 61, wherein the elastomer is obtained by reacting an NCO-terminated prepolymer produced from the bio-based monomer PDI and the at least one polyol with the at least one curing agent.

74. The PDI-based elastomer according to claim 73, wherein the curing agent reacts with the NCO-terminated prepolymer at an NCO-terminated prepolymer to curing agent molar ratio of 0.95:1 to 1.10:

1.

75. The PDI-based elastomer according to claim 73, wherein the curing agent reacts with the NCO-terminated prepolymer at an NCO-terminated prepolymer to curing agent molar ratio of 1.05:

1.

76. The PDI-based elastomer according to claim 73, wherein the NCO-terminated prepolymer is produced by reacting the PDI and the polyol by heating at a temperature ranging from 50 °C to 120 °C.

77. The PDI-based elastomer according to claim 73, wherein the NCO-terminated prepolymer is produced by mixing the PDI and the bio-based polyol in the absence of any catalyst.

78. The PDI-based elastomer according to claim 73, wherein the NCO-terminated prepolymer is produced using a dehydrated polyol.

79. The PDI-based elastomer according to claim 78, wherein the dehydrated polyol has a water content of less than 0.1 wt% based on the weight of the polyol.

80. The PDI-based elastomer according to claim 78, wherein the dehydrated polyol has a water content of less than 0.06 wt% based on the weight of the polyol.

81. The PDI-based elastomer according to claim 73, wherein the NCO-terminated prepolymer has a viscosity ranging from 100 cps to 10000 cps at 70 °C.

82. The PDI-based elastomer according to claim 73, wherein the NCO-terminated prepolymer has a viscosity ranging from 500 cps to 10000 cps at 70 °C.

83. The PDI-based elastomer according to claim 73, wherein the reaction of the NCO-terminated prepolymer with the at least one sterically hindered diamine is carried out under heating with or without a catalyst.

84. The PDI-based elastomer according to any one of claims 58 to 61, wherein the molar ratio of PDI to polyol is at least 1.1:

1.

85. The PDI-based elastomer according to any one of claims 58 to 61, wherein the molar ratio of PDI to polyol is from 1.1:1 to 10:

1.

86. The PDI-based elastomer according to any one of claims 58 to 61, wherein the molar ratio of PDI to polyol is from 1.5:1 to 4:

1.

87. The PDI-based elastomer according to any one of claims 58 to 61, wherein the molar ratio of PDI to polyol is from 2:1 to 3:

1.

88. The PDI-based elastomer according to any one of claims 58 to 61, wherein the PDI-based elastomer exhibits a higher hardness than the isophorone diisocyanate-based elastomer, and the PDI-based elastomer exhibits a higher resilience than the isophorone diisocyanate-based elastomer, wherein the isophorone diisocyanate-based elastomer is prepared using the same polyol, the same curing agent as the PDI-based elastomer and in the same molar ratio and under the same conditions.

89. The PDI-based elastomer according to claim 88, wherein the resilience of the PDI-based elastomer is at least 1.2 times that of the isophorone diisocyanate-based elastomer.

90. The PDI-based elastomer according to any one of claims 58 to 61, wherein the PDI-based elastomer exhibits a higher tensile strength at break at room temperature than the isophorone diisocyanate-based elastomer at room temperature, and the PDI-based elastomer exhibits a higher elongation at break at room temperature than the isophorone diisocyanate-based elastomer at room temperature, wherein the isophorone diisocyanate-based elastomer is prepared using the same polyol, the same curing agent as the PDI-based elastomer and in the same molar ratio and conditions.

91. The PDI-based elastomer according to claim 90, wherein the tensile strength at break of the PDI-based elastomer at room temperature is at least 1.8 times that of the isophorone diisocyanate-based elastomer at room temperature.

92. The PDI-based elastomer according to any one of claims 58 to 61, wherein the PDI-based elastomer exhibits higher abrasion resistance than the isophorone diisocyanate-based elastomer, wherein the isophorone diisocyanate-based elastomer is prepared using the same polyol, the same curing agent as the PDI-based elastomer and in the same molar ratio and conditions.

93. The PDI-based elastomer according to any one of claims 58 to 61, wherein the PDI-based elastomer exhibits higher tear strength than the isophorone diisocyanate-based elastomer, wherein the isophorone diisocyanate-based elastomer is prepared using the same polyol, the same curing agent as the PDI-based elastomer and in the same molar ratio and conditions.

94. The PDI-based elastomer according to any one of claims 58 to 61, wherein the PDI has a biobased content of at least 71%.

95. The PDI-based elastomer according to any one of claims 58 to 61, wherein the PDI is obtained by a method comprising: subjecting a solution comprising cadaverine salt dissolved in an inert solvent in the presence of a tertiary amine base to a liquid-phase phosgenation reaction using a light gas source to convert the cadaverine to PDI, wherein the phosgenation reaction comprises the steps of: maintaining the reaction in a temperature range between 100 °C and 120 °C for a sufficient time to achieve a desired PDI threshold yield, wherein the amount of the tertiary amine base present allows the phosgenation reaction to proceed to completion in the temperature range.

96. The PDI-based elastomer according to claim 95, wherein the sufficient time is at least 1.5 hours.

97. The PDI-based elastomer according to claim 95, wherein the phosgenation reaction is a multi-stage phosgenation reaction, the multi-stage phosgenation reaction at least comprises: A first stage, in which the solution is heated to a first temperature such that the cadaverine reacts with phosgene from the light gas source to produce a dichlorocarbamate intermediate, and a subsequent second stage, in which the solution is further heated to a second temperature higher than the first temperature to subject the dichlorocarbamate intermediate to dehydrochlorination, wherein the second stage comprises the steps of: maintaining the reaction at a temperature between 100 °C and 120 °C for a sufficient time to achieve a PDI threshold yield.

98. The PDI-based elastomer according to claim 97, wherein the first temperature is from 30 to 65 °C.

99. The PDI-based elastomer according to claim 97, wherein the first stage comprises maintaining the solution at the first temperature for at least 0.5 hours.

100. The PDI-based elastomer according to claim 97, wherein the second temperature is at least 10 °C higher than the first temperature.

101. The PDI-based elastomer according to claim 97, wherein the method uses 3 to 30 moles of phosgene per mole of cadaverine salt.

102. The PDI-based elastomer according to claim 97, wherein the method uses at least 4 moles of tertiary amine base per mole of cadaverine salt.

103. The PDI-based elastomer according to claim 97, wherein the cadaverine salt is obtained by fermentation and / or enzymatic conversion, and the content of 2,3,4,5-tetrahydropyridine THP or other cyclic by-product impurities in the cadaverine salt is less than 0.1 wt%.

104. The PDI-based elastomer according to claim 97, wherein the cadaverine salt is cadaverine dihydrochloride.

105. The PDI-based elastomer according to claim 97, wherein the light gas source is triphosgene, and the tertiary amine base reacts with the triphosgene to release phosgene for the phosgenation reaction.

106. The PDI-based elastomer according to claim 97, wherein the tertiary amine base is a heterocyclic amine or a tertiary amine base having an sp 2 -hybridized N atom.

107. The PDI-based elastomer according to claim 97, wherein the tertiary amine base is pyridine.

108. The PDI-based elastomer according to claim 97, wherein the inert solvent comprises chlorobenzene, dichlorobenzene, toluene, nitrobenzene or any mixture thereof or consists of them.

109. The PDI-based elastomer according to claim 97, wherein the inert solvent is a solvent or solvent mixture having a boiling point of at least 120 °C.

110. The PDI-based elastomer according to claim 97, wherein the produced PDI has a content of THP or other cyclic by-product impurities of less than 0.1 wt% before undergoing one or more distillation steps.

111. The PDI-based elastomer according to claim 97, wherein the desired PDI threshold yield is at least 50%. Use of a PDI-based elastomer according to any one of claims 58 to 111 for the production of footwear, linings, metal coatings, pump seals, wiper blades, snow plow blades, valves, tires, agitator blades, rollers, rolls, gaskets, seals, pulleys, bumpers, shock absorbers, bushings, bearings, wear strips, skateboards, machine parts, housings, escalator parts, couplings, clamping blocks, grommets, hammers, impact pads, wood sorting pads, gears or sprockets. Use according to claim 112, wherein the footwear is a sole.

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