Thermoplastic polyurethane elastomer as well as preparation method and application thereof

Abstract

The invention discloses a thermoplastic polyurethane elastomer which comprises a reaction product of a bio-based polyisocyanate component, a bio-based polyol component and an optional chain extender component, the polyisocyanate component comprises 2, 5-bis (methyl isocyanate) furan and / or L-lysine ethyl ester diisocyanate, the bio-based polyol component comprises 2, 5-bis (methyl isocyanate) furan and / or L-lysine ethyl ester diisocyanate, and the chain extender component comprises 2, 5-bis (methyl isocyanate) furan and / or L-lysine ethyl ester diisocyanate. The bio-based polyol component comprises poly (trimethylene carbonate) polyol and / or polylactic acid polyol. According to the invention, the range of raw materials for preparing the polyurethane material is widened, and the prepared thermoplastic polyurethane not only has degradability, but also has thermal plasticity, and the degraded product is non-toxic and harmless and is environment-friendly.

Description

Technical Field

[0001] The present invention relates to the field of polyurethane material synthesis, and in particular to a method for preparing a thermoplastic polyurethane elastomer material. Background Art

[0002] Polyurethane has excellent comprehensive performance and wide application, and is known as the "fifth largest plastic". Its application basically covers all aspects of life, especially in clothing, furniture, automobiles, construction, transportation, medical and other industries. Thermoplastic polyurethane elastomer (TPU), one of the members of the polyurethane family, has outstanding performance in low temperature performance, processing performance, mechanical properties, wear resistance, high resilience, etc. because its raw materials are all difunctional large / small molecular diols and diisocyanates. Because there is no chemical cross-linking between the molecular chains after the synthesis of polyurethane, it is also known as "solid rubber" because it is solid before molding. Thermoplastic polyurethane elastomer has the elasticity of rubber when used, and can be directly molded by thermoplastic plastic direct injection molding, blow molding and other processing methods. Compared with traditional rubber, it has high strength, strong design and wide hardness range; processing does not require plasticizing, vulcanization and mixing processes, and can be directly processed and molded. At the same time, the waste and scraps of thermoplastic polyurethane can be recycled by heating and reshaping.

[0003] At present, the mainstream polyurethane synthetic materials on the market are still mainly derived from non-renewable petroleum-based derivatives. For example, the main raw materials for synthesizing polyurethane, diisocyanates, include 4,4'-diphenylmethane diisocyanate (MDI), isophorone diisocyanate (IPDI), 4,4'-dicyclohexylmethane diisocyanate (HMDI), and toluene diisocyanate (TDI). Among them, TDI and MDI are quite commonly used diisocyanates in the industrial production of polyurethane. Commonly used oligomer diols for TPU synthesis include: polyethylene glycol, polycaprolactone diol, polybutylene adipate diol, polyalkyl diol, polycarbonate diol, etc. Polycarbonate diol is prepared by copolymerization of propylene oxide and CO2. The raw materials of these diisocyanates and oligomer diols are basically derived from petroleum-based. After synthesizing polyurethane and making finished products into the environment, they have high stability and are difficult to degrade in the environment, or degradation will also produce some toxic and harmful compounds into the environment. In addition, improper disposal during use by people has caused serious "white pollution".

[0004] At present, petrochemical resources on the earth are becoming increasingly depleted, while biomass bio-based chemicals are renewable resources that are inexhaustible. In order to reduce human dependence on petroleum-based chemicals and reduce environmental pollution and resource consumption, more and more material researchers and microbiologists are gradually focusing on the bio-based raw materials, the biodegradable structure design of polyurethane materials, and the biodegradation process of polyurethane materials. Summary of the invention

[0005] In view of the deficiencies in the prior art, the present disclosure provides a method for preparing a fully bio-based degradable thermoplastic polyurethane elastomer material, and introduces bio-based polyisocyanate components 2,5-di(methyl isocyanate) furan and / or L-lysine ethyl ester diisocyanate, and bio-based polyol components polytrimethylene carbonate diol and / or polylactic acid diol into the polyurethane material prepared thereby, thereby broadening the range of raw materials for preparing polyurethane materials, and the prepared thermoplastic polyurethane is not only degradable, but also non-toxic and harmless in degradation products, and is environmentally friendly. In addition, the polyurethane material not only has the characteristics of general polyurethane materials, but also has thermoplasticity, so that waste materials or recycled materials of the polyurethane can be hot-melted and then prepared into finished products by injection molding, film blowing, molding, etc.

[0006] According to a first aspect of the present disclosure, a thermoplastic polyurethane elastomer is provided, which comprises a reaction product of a bio-based polyisocyanate component, a bio-based polyol component and an optional chain extender component, wherein the polyisocyanate component comprises 2,5-di(methyl isocyanate)furan and / or L-lysine ethyl ester diisocyanate, and the bio-based polyol component comprises polytrimethylene carbonate polyol and / or polylactic acid polyol.

[0007] In some embodiments, in the polyisocyanate component, the mass content of 2,5-di(methyl isocyanate)furan is 0-100%, preferably 10-90%, more preferably 10-50%. In some specific embodiments, in the polyisocyanate component, the mass content of 2,5-di(methyl isocyanate)furan is 0, 10%, 20%, 30%, 40%, 50%, 60%, 70%, 80%, 90%, 100% or any value therebetween.

[0008] In some embodiments, in the polyisocyanate component, the mass content of the L-lysine ethyl ester diisocyanate is 0-100%, preferably 10-90%, and more preferably 50-90%. In some specific embodiments, in the polyisocyanate component, the mass content of the L-lysine ethyl ester diisocyanate is 0, 10%, 20%, 30%, 40%, 50%, 60%, 70%, 80%, 90%, 100% or any value therebetween.

[0009] In some embodiments, the mass content of the polytrimethylene carbonate polyol in the bio-based polyol component is 0-100%, preferably 0-50%, and more preferably 15-30%. In some specific embodiments, the mass content of the polytrimethylene carbonate polyol in the bio-based polyol component is 0, 10%, 15%, 20%, 25%, 30%, 40%, 50%, 60%, 70%, 80%, 90%, 100% or any value therebetween.

[0010] In some embodiments, the mass content of the polylactic acid polyol in the bio-based polyol component is 0-100%, preferably 50%-100%, and more preferably 70-85%. In some specific embodiments, the mass content of the polylactic acid polyol in the bio-based polyol component is 0, 10%, 20%, 30%, 40%, 50%, 60%, 70%, 75%, 80%, 85%, 90%, 100% or any value therebetween.

[0011] In some embodiments, the number average molecular weight of the bio-based polyol is 1000-10000 g / moL, for example, 1000 g / moL, 2000 g / moL, 4000 g / moL, 6000 g / moL, 8000 g / moL, 10000 g / moL or any value therebetween.

[0012] In some embodiments, the polytrimethylene carbonate polyol is polytrimethylene carbonate diol.

[0013] In some embodiments, the polylactic acid polyol is polylactic acid diol.

[0014] In some embodiments, the bio-based polyol component includes polytrimethylene carbonate diol and polylactic acid diol.

[0015] In some embodiments, the mass ratio of the polytrimethylene carbonate diol to the polylactic acid diol is 1:(0.1-10), preferably 1:(0.5-5), and more preferably 1:(1-2.5). In some specific embodiments, the mass ratio of the polytrimethylene carbonate diol to the polylactic acid diol is 1:0.1, 1:0.5, 1:1, 1:2, 1:2.5, 1:3, 1:4, 1:6, 1:8, 1:10 or any value therebetween.

[0016] In some embodiments, the chain extender comprises a diol. Preferably, the chain extender comprises at least one of ethylene glycol, 1,3-propylene glycol, 1,4-butanediol, 1,5-pentanediol, and 1,6-hexanediol. More preferably, the chain extender is a bio-based chain extender.

[0017] In some embodiments, the mass of the bio-based polyisocyanate component is 0.1-50% of the mass of the bio-based polyol component, for example, 0.1%, 0.5%, 1%, 5%, 10%, 15%, 20%, 25%, 30%, 40%, 50%.

[0018] In some embodiments, the mass of the chain extender component is 0-10%, preferably 0-3%, of the sum of the mass of the polyisocyanate component and the bio-based polyol component. In some specific embodiments, the mass of the chain extender component is 0, 0.1%, 0.5%, 1%, 3%, 5%, 7%, 10% or any value therebetween of the sum of the mass of the polyisocyanate component and the bio-based polyol component.

[0019] In some embodiments, the elongation at break of the thermoplastic polyurethane elastomer is 300%-800%, preferably 400-600%. In some specific embodiments, the elongation at break of the thermoplastic polyurethane elastomer is 300%, 400%, 500%, 600%, 700%, 800% or any value therebetween.

[0020] In some embodiments, the tensile strength of the thermoplastic polyurethane elastomer is 2MPa-30MPa, preferably 6.5MPa-20MPa. In some specific embodiments, the tensile strength of the thermoplastic polyurethane elastomer is 2MPa, 5MPa, 10MPa, 15MPa, 20MPa, 25MPa, 30MPa or any value therebetween.

[0021] In some embodiments, the glass transition temperature of the thermoplastic polyurethane elastomer is less than 60° C., preferably 30° C.-50° C. In some specific embodiments, the glass transition temperature of the thermoplastic polyurethane elastomer is 30° C., 35° C., 40° C., 45° C., 50° C. or any value therebetween.

[0022] In some embodiments, the melt index of the thermoplastic polyurethane elastomer is 10 g / 10min-30 g / 10min, preferably 15 g / 10min-25 g / 10min. In some specific embodiments, the melt index of the thermoplastic polyurethane elastomer is 10 g / 10min, 15 g / 10min, 20 g / 10min, 25 g / 10min, 30 g / 10min or any value therebetween.

[0023] According to a second aspect of the present disclosure, a method for preparing the thermoplastic polyurethane elastomer according to the first aspect is provided, the method comprising reacting the bio-based polyisocyanate component, the bio-based polyol component and optionally the chain extender component.

[0024] In some embodiments, the reaction temperature is 80-200° C., preferably 90° C.-150° C. In some specific embodiments, the reaction temperature is 80° C., 90° C., 100° C., 120° C., 140° C., 150° C., 160° C., 180° C., 200° C. or any value therebetween.

[0025] In some embodiments, the reaction time is 0.5h-5h, preferably 1h-3h. In some specific embodiments, the reaction time is 0.5h, 1h, 2h, 3h, 4h, 5h or any value therebetween.

[0026] In some embodiments, the reaction is carried out with or without a solvent. In some embodiments, the solvent comprises toluene.

[0027] In some embodiments, the 2,5-di(methyl isocyanate)furan in the bio-based polyisocyanate component is prepared by first reacting furan dimethylamine with hydrochloric acid gas to form a salt, and then reacting the salt with phosgene and / or triphosgene in a solvent.

[0028] In some embodiments, the solvent includes chlorobenzene and / or o-dichlorobenzene.

[0029] According to the third aspect of the present disclosure, provided is the use of the thermoplastic polyurethane elastomer described in the first aspect or the thermoplastic polyurethane elastomer obtained by the preparation method described in the second aspect in clothing materials, furniture materials, automotive materials, construction materials, transportation materials or medical materials.

[0030] In some embodiments, the thermoplastic polyurethane elastomer used in the application is degradable and thermoplastic, and can be heated and melted to prepare a finished product through injection molding, film blowing, etc.

[0031] The present disclosure has the following beneficial effects:

[0032] (1) In the synthesis of bio-based degradable thermoplastic polyurethane elastomer materials, bio-based polyisocyanate components 2,5-di(methyl isocyanate) furan and / or L-lysine ethyl ester diisocyanate, as well as bio-based polyol components polytrimethylene carbonate diol and / or polylactic acid diol were introduced, which broadened the source of raw materials in the field of polyurethane synthesis;

[0033] (2) Using polylactic acid diol as the main component and polytrimethylene carbonate diol as the auxiliary component, the problem of poor flexibility of polyurethane materials caused by excessive use of polylactic acid diol was successfully solved;

[0034] (3) The raw materials for preparing bio-based degradable thermoplastic polyurethane elastomer materials do not rely on petrochemical resources that are about to be exhausted, but are completely derived from bio-based materials, thus achieving the renewability of raw materials;

[0035] (4) The prepared bio-based degradable thermoplastic polyurethane elastomer material not only has the basic characteristics of general polyurethane such as waterproofness, softness, wear resistance, and breathability, but also has the characteristics of thermoplasticity, degradability, and waste recycling. At the same time, the degradation products during the degradation process are non-toxic and harmless, and are environmentally friendly. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Figure 1 2,5-di(methyl isocyanate)furan prepared according to some embodiments of the present disclosure 1 H-NMR spectrum.

[0037] Figure 2 2,5-di(methyl isocyanate)furan prepared according to some embodiments of the present disclosure 13 C-NMR spectrum. DETAILED DESCRIPTION

[0038] The present disclosure provides a method for preparing a fully bio-based thermoplastic polyurethane elastomer, wherein the bio-based thermoplastic polyurethane elastomer material is synthesized by a one-step method including bio-based polyols, particularly polytrimethylene carbonate polyols and / or polylactic acid polyols; bio-based isocyanates, particularly L-lysine ethyl ester diisocyanate and / or 2,5-bis(isocyanatomethyl) furan (Furan, 2,5-bis(isocyanatomethyl)), and optional small molecule diol chain extenders and optional organic solvents, and no organic metal catalyst is used in the synthesis process. The polyurethane prepared by the present disclosure has thermoplasticity, high tensile strength, good resilience, large elongation at break, adjustable hardness, and can also intuitively compare the performance of the reaction material; the processing fluidity is good, because its molecular chain is in a linear structure, basically not cross-linked, and can be repeatedly processed and used in use. The current conventional molding processing methods, such as extrusion, injection molding, and molding are applicable to the material, and the method is also a new method for modifying polylactic acid, which reduces the glass transition temperature of polylactic acid and increases the elongation at break.

[0039] In some embodiments, the polylactic acid diol is obtained by ring-opening polymerization of lactide and a bio-based small molecule linear diol under the action of a catalyst.

[0040] In some embodiments, the polytrimethylene carbonate diol is obtained by ring-opening polymerization of trimethylene carbonate and a bio-based small molecule linear diol under the action of a catalyst.

[0041] In some embodiments, the bio-based small molecule linear diol includes at least one of ethylene glycol, 1,3-propylene glycol, 1,4-butanediol, 1,5-pentanediol, and 1,6-hexanediol.

[0042] In some embodiments, the polytrimethylene carbonate diol has the structure shown below:

[0043]

[0044] In some embodiments, the polytrimethylene carbonate diol is prepared by reacting trimethylene methyl carbonate with a bio-based linear diol as shown in the following formula;

[0045]

[0046] In some embodiments, 2,5-bis(isocyanatomethyl)furan has the structure shown below:

[0047]

[0048] In some embodiments, the L-lysine ethyl ester diisocyanate is obtained by reacting lysine from biological fermentation with triphosgene / phosgene.

[0049] In some embodiments, the 2,5-bis(isocyanatomethyl)furan is synthesized by converting bio-based sugar into 5-hydroxymethylfurfural, which is then converted into furan dimethylamine through a chemical reaction and then reacted with triphosgene.

[0050] In some embodiments, the 2,5-di(isocyanatomethyl)furan is prepared by first reacting furan dimethylamine with hydrochloric acid gas to form a salt, and then reacting with phosgene or triphosgene in a chlorobenzene / o-dichlorobenzene solvent, as shown in the following formula:

[0051]

[0052] In some embodiments, the reaction does not require additional catalysts, and only a trace amount of catalyst introduced during the preparation of the bio-based polyol component is required to initiate the reaction.

[0053] In some embodiments, the reaction is performed by a solvent-free method or a solvent method.

[0054] In some embodiments, the solvent-free method comprises the following steps: heating the bio-based polyol component into a molten state in a reaction vessel, degassing and removing moisture under vacuum pressure (0.5-2h, for example 0.5h), adding the bio-based polyisocyanate component and the optional chain extender component at the molten temperature under the protection of high-purity nitrogen, and reacting at the temperature (0.5-5.0h, for example 2.0h) to obtain a bio-based degradable thermoplastic polyurethane elastomer.

[0055] In some embodiments, the solvent method comprises the following steps: heating and dissolving a bio-based polyol component and an optional chain extender component in a solvent (e.g., toluene), refluxing with water under nitrogen protection until the solvent is free of water, then adding a polyisocyanate component at this temperature while stirring, and then keeping the temperature (80-200° C., for example, to 100° C.) to the reflux temperature of toluene for reaction (0.5-5.0 h, for example, 2.0 h), and removing the solvent under reduced pressure to obtain a bio-based degradable thermoplastic polyurethane elastomer.

[0056] In some specific embodiments, the preparation of the thermoplastic polyurethane elastomer material comprises the following steps:

[0057] (1) Synthesis of bio-based polyisocyanate components

[0058] Dissolve furan dimethylamine in methyl tert-butyl ether (MTBE), introduce excess hydrochloric acid gas at low temperature to make furan dimethylamine completely salified, filter, rinse with MTBE until there is no hydrochloric acid gas, and dry in vacuum. Disperse the dried furan dimethylamine hydrochloride in a solvent, continue to introduce phosgene or triphosgene solution under heating until the solid basically disappears, blow off excess phosgene with nitrogen, filter, remove the solvent with concentrated acid from the mother liquor, and distill under reduced pressure to obtain 2,5-di(methyl isocyanate)furan.

[0059] The amount of triphosgene used is 1 to 10 equivalents of furandimethylamine hydrochloride dissolved in 5 times the mass of chlorobenzene solution and continuously added; the amount of phosgene used is 3 to 30 equivalents of furandimethylamine hydrochloride and continuously introduced; the time for adding triphosgene solution or introducing phosgene is 8 to 12 hours, and the reaction temperature is 80 to 130°C.

[0060] The synthesis of L-lysine ethyl diisocyanate reference patent CN115160185A.

[0061] (2) Synthesis of bio-based polyol components

[0062] Add trimethylene carbonate to a clean reaction bottle, heat and melt, then heat to 60-90℃ and vacuum decompress for 0.5h-1.0h, add measured bio-based linear small molecule diol and catalyst stannous octoate in sequence under nitrogen stirring, then heat to 120-150℃ under nitrogen protection and polymerize for 3-5h to obtain polytrimethylene carbonate diol. The synthesis of trimethylene carbonate monomer is prepared by reference to patent CN114874180A.

[0063] Add L-lactide to a clean reaction bottle, heat to 80-100°C under nitrogen protection and vacuum decompression for 0.5h-1.0h, add 1,4-butanediol and stannous octoate through a syringe, stir evenly, then heat to 120-150°C and keep warm for 3-5h to obtain polylactic acid diol.

[0064] The amount of bio-based linear small molecule diol added is determined according to the designed molecular weight of polytrimethylene carbonate diol, and the amount of the catalyst is 0.1% to 0.01% of the monomer mass.

[0065] (3) Synthesis of thermoplastic polyurethane elastomer

[0066] Solvent-free method: The bio-based polyol component is heated to a molten state in a reaction vessel, and the vapor and moisture are removed by vacuum decompression (0.5-2h, for example, 0.5h). Then, the bio-based polyisocyanate component and the optional chain extender component are added at the molten temperature under the protection of high-purity nitrogen, and the reaction is kept warm (0.5-5.0h, for example, 2.0h) to obtain a bio-based degradable thermoplastic polyurethane elastomer.

[0067] Among them, in the solvent-free method, the bio-based polyol component is added to a clean reaction bottle and heated to melt, and the melting temperature depends on the molecular weight of the polyol.

[0068] Solvent method: The bio-based polyol component and the optional chain extender component are heated and dissolved in a solvent (such as toluene), and refluxed under nitrogen protection to remove water until the solvent is free of water. Then, the polyisocyanate component is added under stirring at this temperature and kept warm (80-200°C, for example, to 100°C) to the reflux temperature of toluene for reaction (0.5-5.0h, for example, 2.0h), and the solvent is removed under reduced pressure to obtain a bio-based degradable thermoplastic polyurethane elastomer.

[0069] Among them, in the solvent method, a measured amount of bio-based polyol component and an optional chain extender component are added to a clean reaction bottle, a reflux water separation device is set up, heated to dissolve and reflux water separation until there is no water, and then cooled to 80-110°C, and the measured amount of diisocyanate is reacted at this temperature for 0.5-5.0h, for example, 2.0h, and the solvent is removed under reduced pressure to obtain a bio-based degradable polyurethane elastomer.

[0070] The fully bio-based degradable thermoplastic polyurethane elastomer material disclosed in the present invention can be used in all thermoplastic plastic application scenarios, and the performance can be adjusted as needed.

[0071] In order to make the purpose, technical scheme and advantages of the present disclosure more clear, the present disclosure is further described in detail below in conjunction with the accompanying drawings and embodiments. The specific embodiments described herein are only used to explain the present disclosure and are not intended to constitute any limitation to the present disclosure. In addition, in the following description, the description of well-known structures and technologies is omitted to avoid unnecessary confusion of the concepts of the present disclosure. Such structures and technologies are also described in many publications.

[0072] Example 1 Preparation of Bio-based Polyisocyanate Component

[0073] (1) Preparation of 2,5-di(methyl isocyanate)furan (FDI)

[0074] 80 g of furandimethylamine was dissolved in 400 mL of methyl tert-butyl ether, and the temperature was lowered to 5°C under nitrogen protection. Dry hydrogen chloride gas was slowly introduced at 5-10°C until saturation to precipitate a large amount of solid. After saturation, the mixture was kept at 5-10°C for 3.0 h and filtered. The filter cake was washed with methyl tert-butyl ether until there was no hydrogen chloride gas. The mixture was dried in vacuo at 45°C to obtain 125.3 g of light yellow solid with a yield of 99.26%.

[0075] Take 50g of furan dimethylamine hydrochloride and disperse it in 250mL of chlorobenzene. Set up stirring, reflux, and tail gas absorption equipment, replace with nitrogen, and heat to reflux. Slowly add 89.43g of triphosgene and 250mL of chlorobenzene solution through a syringe pump under reflux. Set it to drip in 8.0h and control the dripping speed. After dripping, keep warm and reflux for 3.0h. Blow off the excess phosgene with nitrogen, filter out the solid in the solution, and concentrate the solvent under reduced pressure. Under a vacuum of 1-2mmHg, the product is distilled under reduced pressure to obtain 35.2g of colorless liquid with a yield of 78.67%. It was confirmed by nuclear magnetic resonance that it was 2,5-di(methyl isocyanate)furan (FDI), with deuterated chloroform as the solvent. 1 H-NMR and 13 C-NMR Figure 1 and Figure 2 .

[0076] (2) Preparation of L-lysine ethyl diisocyanate (LDI)

[0077] The synthesis of the preparation of L-lysine ethyl diisocyanate (LDI) is based on Example 1 of patent CN115160185A. Example 2 Preparation of bio-based polyol component

[0078] (1) Synthesis of polytrimethylene carbonate polyol

[0079] Take 190.9880g of trimethylene carbonate into a clean reaction bottle, heat to 80℃ under nitrogen protection and vacuum reduce pressure for 0.5h, add 1,4-butanediol 9.0120g and stannous octoate 0.2g through a syringe, stir evenly, heat to 140℃, keep warm and react for 4.0h, pour out while hot, cool, seal and dry for storage to obtain polytrimethylene carbonate diol. The number average molecular weight is calculated by titrating the hydroxyl value and is 1997g / moL.

[0080] (2) Synthesis of polylactic acid polyol

[0081] Take 191.81g of L-lactide into a clean reaction bottle, heat to 95℃ under nitrogen protection and vacuum reduce pressure for 0.5h, add 8.19g of 1,4-butanediol and 0.2g of stannous octoate through a syringe, stir evenly, then heat to 140℃ and keep the reaction for 4.0h, pour out while hot, cool, seal and dry for storage to obtain polylactic acid diol, and the number average molecular weight calculated by nuclear magnetic hydrogen spectrum is 2201g / moL.

[0082] The operation of polylactic acid diol and polytrimethylene carbonate diol with other molecular weights is carried out according to this embodiment after the molecular weight is designed.

[0083] Embodiments 3 to 14

[0084] According to the raw material formula in Table 1, multiple groups of bio-based degradable thermoplastic polyurethane elastic materials were prepared.

[0085]

[0086] According to the raw material formula in Table 1, the bio-based degradable polyurethane elastomer material of each embodiment was prepared by the following solvent-free method and solvent method preparation method steps:

[0087] (1) Preparation of biodegradable thermoplastic polyurethane elastomers by solvent-free method

[0088] (1-1) Example 3 was prepared by a solvent-free method. Polylactic acid diol and polytrimethylene carbonate diol were added to a clean three-necked flask. After nitrogen replacement, the temperature was raised to 120° C. under nitrogen protection and vacuum pressure was reduced for 0.5 h.

[0089] (1-2) adding L-lysine ethyl diisocyanate (LDI) and a chain extender under nitrogen protection and rapid stirring;

[0090] (1-3) After the viscosity increases after stirring evenly, stop stirring and keep the temperature at 120°C to 140°C for 2.0 hours, cool to room temperature, and the preparation of bio-based degradable polyurethane elastomer by solvent-free method is completed. Samples are taken and tested for performance;

[0091] (2) Preparation of biodegradable thermoplastic polyurethane elastomers by solvent method

[0092] (2-1) Examples 4-23 and Comparative Example 1 were prepared by the solvent method. Bio-based polyol polylactic acid diol and / or polytrimethylene carbonate diol were added to a clean three-necked flask, and dry toluene was added in an amount of 5 times the total mass of the bio-based polyol;

[0093] (2-2) A mechanical stirrer, a water separator, a condenser and a nitrogen bag were installed on the three-necked flask and replaced with nitrogen;

[0094] (2-3) Heat to reflux and remove water until there is no water for about 2.0 hours;

[0095] (2-4) cooling to 100° C. under nitrogen protection, adding the chain extender and / or bio-based polyisocyanate component in sequence under rapid stirring, and keeping the temperature for 2.0 h;

[0096] (2-5) The reflux device is replaced by a distillation device, toluene is evaporated under reduced pressure, and high vacuum degassing is performed to complete the preparation of the bio-based degradable thermoplastic polyurethane elastomer, and samples are taken and prepared for performance testing.

[0097] Test Case

[0098] The following performance tests were carried out on the bio-based degradable thermoplastic polyurethane elastomer materials prepared in the above examples and comparative examples, respectively. The test data are shown in Table 2.

[0099] (1) Gel Permeation Chromatography (GPC) Test

[0100] A solution with a sample concentration of 4 mg / mL was prepared, the flow rate was controlled at 1 mL / min, the mobile phase was tetrahydrofuran solution, and the number average molecular weight, weight average molecular weight and polydispersity coefficient of the sample were tested.

[0101] (2) Differential Scanning Calorimeter (DSC) Test

[0102] Weigh 5-10 mg of sample into a crucible, heat at a rate of 10°C / min, in the temperature range of -60 to 200°C, under N2 conditions, and measure the glass transition temperature of the sample.

[0103] (3) Mechanical properties test

[0104] Take 4g of thermoplastic polyurethane elastomer material and dissolve it in 50mL of dichloromethane, pour it on a 15cm*15cm glass plate to dry into a film, take out the film and cut it into smooth strips with a length of 80mm, a width of 14mm and a thickness of 0.124mm. Prepare three parallel specimens for each group of samples, and carry out tensile tests on an electronic universal tensile testing machine with a maximum force of 10kN and a tensile rate of 50mm / min.

[0105] (4) Melt index (MI) test

[0106] Weigh 6 to 8 g of sample and put it into a melt flow rate tester at a temperature of 190°C. Cut the sample once every 0.5 minutes under the action of a 1835 g weight. After cooling to room temperature, weigh it (the difference between the maximum and minimum values ​​should be less than 10% of the average value), and calculate the melt index (MI).

[0107] Table 2. Material performance test data

[0108] Mn(million) Elongation at break (%) Tensile strength(MPa) Glass transition temperature (Tg / ℃) Melt index (g / 10min) Example 3 5.20 597.98 9.47 38.00 19.15 Example 4 5.83 368.83 11.52 38.00 19.80 Example 5 5.52 388.84 11.02 37.70 18.83 Example 6 5.90 455.79 10.83 37.10 19.88 Example 7 5.82 534.90 8.25 36.60 19.83 Example 8 5.09 308.22 22.25 46.19 19.56 Example 9 5.33 750.24 2.01 22.50 18.89 Example 10 5.62 402.11 10.11 39.19 18.57 Embodiment 11 5.44 375.22 11.12 38.04 18.89 Example 12 5.97 360.99 11.51 36.08 17.86 Example 13 4.91 515.54 14.81 39.33 20.11 Embodiment 14 7.00 551.75 8.99 38.50 18.32 Embodiment 15 6.03 462.91 15.08 37.63 18.43 Example 16 8.44 490.50 14.12 44.70 17.49 Embodiment 17 8.46 478.63 18.00 40.90 17.10 Embodiment 18 8.50 550.13 10.50 45.31 16.93 Embodiment 19 8.73 550.40 10.03 45.22 16.84 Embodiment 20 8.73 466.40 13.20 46.90 16.79 Embodiment 21 8.51 455.32 17.50 47.34 17.33 Embodiment 22 5.40 499.34 6.85 46.50 19.22 Embodiment 23 8.84 577.10 13.37 46.20 17.08 Comparative Example 1 8.19 530.80 7.36 43.91 16.91

[0109] From Table 2, we can see that:

[0110] a. The glass transition temperature of the bio-based degradable thermoplastic polyurethane elastomer material disclosed in the present invention is lower than that of polylactic acid. According to investigation, the glass transition temperature of polylactic acid is 60-65° C., indicating that the material has better low temperature resistance than polylactic acid and can maintain its elasticity and functionality at lower temperatures;

[0111] b. By comparing Example 23 with Comparative Example 1, the performance of the material with bio-based isocyanate added is not much different from that with petroleum-based 4,4'-methylenebis(phenyl isocyanate), that is, bio-based isocyanate can replace petroleum-based isocyanate, and from the perspective of tensile strength and elongation at break, the material with bio-based isocyanate has better performance and can better meet the needs of various engineering applications;

[0112] c. The melt index of the bio-based degradable thermoplastic polyurethane elastomer material disclosed in the present invention is 16.79-20.11 g / 10 min, indicating that the material has thermoplasticity;

[0113] d. It can be seen from Examples 4 to 8 that as the amount of polytrimethylene carbonate polyol increases, the elongation at break of the synthesized material increases and the tensile strength decreases, indicating that the addition of polytrimethylene carbonate polyol can increase the flexibility of the material.

[0114] e. It can be seen from Examples 10-12 that when 2,5-di(methyl isocyanate)furan and L-lysine ethyl diisocyanate are used together, as the amount of 2,5-di(methyl isocyanate)furan increases, the elongation at break of the material decreases and the tensile strength increases, indicating that the hardness of the material increases.

[0115] The technical solution of the present disclosure is not limited to the above-mentioned specific embodiments, and all technical variations made according to the technical solution of the present disclosure fall within the protection scope of the present disclosure.

Claims

1. A thermoplastic polyurethane elastomer comprising a reaction product of a bio-based polyisocyanate component, a bio-based polyol component and an optional chain extender component, wherein: The polyisocyanate component includes 2,5-di(methyl isocyanate)furan and / or L-lysine ethyl ester diisocyanate, and the bio-based polyol component includes polytrimethylene carbonate polyol and / or polylactic acid polyol.

2. The thermoplastic polyurethane elastomer according to claim 1, characterized in that In the bio-based polyisocyanate component, the mass content of 2,5-di(methyl isocyanate)furan is 0-100%, preferably 10-90%, more preferably 10-50%; and / or In the bio-based polyisocyanate component, the mass content of the L-lysine ethyl ester diisocyanate is 0-100%, preferably 10-90%, more preferably 50-90%; and / or In the bio-based polyol component, the mass content of the polytrimethylene carbonate polyol is 0-100%, preferably 0-50%, more preferably 15-30%; and / or In the bio-based polyol component, the mass content of the polylactic acid polyol is 0-100%, preferably 50%-100%, and more preferably 70-85%.

3. The thermoplastic polyurethane elastomer according to claim 1 or 2, characterized in that: The number average molecular weight of the bio-based polyol component is 1000-10000 g / moL; Preferably, the polytrimethylene carbonate polyol is polytrimethylene carbonate diol; Preferably, the polylactic acid polyol is polylactic acid diol; Preferably, the bio-based polyol component comprises polytrimethylene carbonate diol and polylactic acid diol; More preferably, the mass ratio of the polytrimethylene carbonate diol to the polylactic acid diol is 1:(0.1-10), preferably 1:(0.5-5), and more preferably 1:(1-2.5).

4. The thermoplastic polyurethane elastomer according to any one of claims 1 to 3, characterized in that The chain extender component includes a diol. Preferably, the chain extender component includes at least one of ethylene glycol, 1,3-propylene glycol, 1,4-butanediol, 1,5-pentanediol, and 1,6-hexanediol. More preferably, the chain extender component is a bio-based chain extender.

5. The thermoplastic polyurethane elastomer according to any one of claims 1 to 4, characterized in that The mass of the bio-based polyisocyanate component is 0.1-50% of the mass of the bio-based polyol component, and / or The mass of the chain extender component is 0-10%, preferably 0-3%, of the sum of the mass of the polyisocyanate component and the bio-based polyol component.

6. The thermoplastic polyurethane elastomer according to any one of claims 1 to 5, characterized in that The elongation at break of the thermoplastic polyurethane elastomer is 300%-800%, preferably 400-600%; and / or The tensile strength of the thermoplastic polyurethane elastomer is 2MPa-30MPa, preferably 6.5MPa-20MPa; and / or The glass transition temperature of the thermoplastic polyurethane elastomer is less than 60°C, preferably 20°C-50°C; and / or The melt index of the thermoplastic polyurethane elastomer is 10 g / 10 min-30 g / 10 min, preferably 15 g / 10 min-25 g / 10 min.

7. The method for preparing a thermoplastic polyurethane elastomer according to any one of claims 1 to 6, comprising reacting the bio-based polyisocyanate component, the bio-based polyol component and the optional chain extender component.

8. The preparation method according to claim 7, characterized in that: The reaction temperature is 80-200°C, preferably 90-150°C; and / or The reaction time is 0.5h-5h, preferably 1h-3h; and / or The reaction is carried out with or without a solvent, preferably, the solvent comprises toluene.

9. The preparation method according to claim 7 or 8, characterized in that: The 2,5-di(methyl isocyanate)furan in the bio-based polyisocyanate component is prepared by first salifying furan dimethylamine with hydrochloric acid gas, and then reacting with phosgene and / or triphosgene in a solvent; preferably, the solvent includes chlorobenzene and / or o-dichlorobenzene.

10. Use of the thermoplastic polyurethane elastomer according to any one of claims 1 to 6 or the thermoplastic polyurethane elastomer obtained by the preparation method according to any one of claims 7 to 9 in clothing materials, furniture materials, automobile materials, construction materials, transportation materials or medical materials.

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