Thermoplastic polyurethane material as well as preparation method and application thereof

Abstract

The invention discloses a thermoplastic polyurethane material as well as a preparation method and application thereof, and belongs to the technical field of polyurethane materials. The thermoplastic polyurethane material is TPU-M, M represents cations, indolediol and cation functional groups are introduced into a polyurethane framework of the polyurethane material, cation-pi interaction between macromolecular chains is successfully established, and dynamic crosslinking of the macromolecular chains is achieved. Metal ions serve as cross-linking points between polymer chains, and compared with dynamic bonds such as hydrogen bonds and metal coordination bonds formed by other supramolecules in a point-to-point mode, positive ions-pi belong to point-to-surface interaction, the forming and constructing range of the acting force is enlarged, construction is simpler and more convenient, polymer chain cross-linking is faster, and polymer chain cross-linking efficiency is improved. And excellent reinforcing and toughening effects of the material are achieved.

Description

Technical Field

[0001] The invention relates to the technical field of polyurethane materials, in particular to a thermoplastic polyurethane material and a preparation method and application thereof. Background Art

[0002] Polyurethane is a material widely used in people's daily life and production. It is favored for its excellent properties such as good wear resistance, wide hardness range, large adjustable performance range, excellent processing performance, and degradability. It is widely used in the fields of construction, automobiles, furniture, medical equipment, etc. However, traditional polyurethane materials still have some defects, such as poor toughness, poor impact resistance, short life, etc., which gradually cannot meet people's growing needs. It is well known that the mechanical strength of polymer materials can be effectively improved by physical or chemical modification in polymer systems. However, while the mechanical strength of polymer materials is improved, their toughness will mostly deteriorate, they will be brittle, their resistance to impact and stress cracks will decrease, and their plastic deformation will be constrained, thus limiting the application range of polymer materials.

[0003] In order to obtain polymer materials with both high strength and high toughness, people usually add various nanofillers to the polymer matrix, but they have to consider the balance between mechanical strength and toughness. Generally, when the strength increases, the toughness will decrease, and vice versa.

[0004] In addition, although the thermal stability and mechanical strength of the polymer can be further enhanced through traditional chemical cross-linking, the toughness of the cross-linked polymer will be affected and it will become difficult to recycle and cannot be recast. Waste materials can only be disposed of by landfill, which is not conducive to environmental protection and rational reuse of resources. Summary of the invention

[0005] In order to solve the above problems, the present invention provides a thermoplastic polyurethane material and a preparation method and application thereof.

[0006] The present invention is achieved through the following technical solutions:

[0007] A thermoplastic polyurethane material, wherein the thermoplastic polyurethane material is TPU-M, wherein M represents a cation, and the molecular formula of TPU is

[0008] A method for preparing a thermoplastic polyurethane material, wherein the polymerization route of the TPU is as follows:

[0009]

[0010] The preparation method of TPU comprises the following steps: adding isophorone diisocyanate IPDI, PEG400 and DBTDL into a double-necked flask under a nitrogen environment, performing prepolymerization at 70-90° C. for 1-2 hours, adding indole diol after the prepolymerization, diluting with DMF, the viscosity increases rapidly after the addition of indole diol, adjusting the rotation speed and adding DMF, continuing the reaction at 70-90° C. for 3-4 hours, and obtaining a TPU polymer solution after the polymerization is completed; wherein the molar feed ratio of IPDI:PEG400:indole diol is 2:1:1;

[0011] The preparation method of TPU-M comprises the following steps: taking a TPU polymer solution in a small glass bottle, uniformly dispersing the chloride corresponding to the accurately weighed cation M in DMSO by ultrasonication, and 2+ The addition amount is 0%-0.15% of the molar amount of indole in the polymer, and is added to the polymer solution according to the molar ratio and ultrasonically mixed to obtain a TPU-M polymer solution; after ultrasonic homogenization, the polymer solution is poured into a mold plate, placed in an oven at 80° C. and dried for 24 hours to remove the solvent, and after drying, the mold plate is taken out and cooled to room temperature, and the film is peeled off to obtain a TPU-M film material;

[0012] The synthetic route of the indolediol is as follows:

[0013]

[0014] The preparation method of the indolediol comprises the following steps:

[0015] (1) Tryptophan protection: weigh chlorosilane in a reaction bottle, heat to 90-120°C, add dichloromethane to completely dissolve, then place in an ice bath, add a dichloromethane mixed solution of imidazole and tryptophan at a rate of 1-3 seconds / drop, stir overnight at room temperature of 20-25°C, then extract with brine and ethyl acetate to obtain a tryptophan protected product; wherein the molar ratio of chlorosilane:tryptophan:imidazole is 1:1:1.5-2.0;

[0016] (2) Secondary protection: dissolve the tryptophan protected product in DMF under ice bath conditions, add NaH and stir for 1-1.5h, then drop a mixed solution of bromosilane and DMF, heat to 90-110°C and react for 3-4h, add water to the reaction flask until no bubbles are generated, extract with water and ethyl acetate, remove the upper layer solution, add anhydrous magnesium sulfate and let stand overnight, then concentrate and purify by column to obtain the tryptophan secondary protected product. The developing solvent for column purification is PE:EA=60:1 and 5% triethylamine;

[0017] (3) Deprotection: The second protection product of the tryptophan was dissolved in tetrahydrofuran and then added with tetrabutylammonium fluoride to react at room temperature for 1.5 h. After extraction with water and ethyl acetate, the mixture was purified by column chromatography and dried to finally obtain indolediol.

[0018] The cation M is Mg 2+ 、Na + , Cu 2+ , K + One of them.

[0019] The preparation method of TPU comprises the following steps: adding 1.125 parts by weight of isophorone diisocyanate IPDI, 1 part by weight of PEG400, and 1.5-2 parts by weight of DBTDL into a double-necked flask under a nitrogen environment, performing prepolymerization at 70-90° C. for 1-2 hours, adding 0.274 parts by weight of indole diol after the prepolymerization, diluting with 4-24 parts by weight of DMF, the viscosity increases rapidly after the addition of indole diol, and the rotation speed needs to be adjusted and 0.8-10 parts by weight of DMF needs to be added, and the reaction is continued at 70-90° C. for 3-4 hours, and a TPU polymer solution is obtained after the polymerization is completed; wherein the molar feed ratio of IPDI:PEG400:indole diol is 2:1:1.

[0020] An application of a thermoplastic polyurethane material, wherein the TPU-M polymer is pre-dried and then extruded into granules for use as a cable sheath material.

[0021] Compared with the prior art, the present invention has the following beneficial effects:

[0022] The polyurethane material of the present invention introduces indole diol and cationic functional groups into the polyurethane skeleton, which can successfully establish cation-π interactions between polymer chains and realize dynamic crosslinking of polymer chains. Metal ions act as crosslinking points between polymer chains. Compared with other supramolecular "point-to-point" dynamic bonds such as hydrogen bonds and metal coordination bonds, cation-π belongs to "point-to-face" interactions. The formation and construction range of this force is expanded, the construction is simpler and more convenient, and the polymer chains are crosslinked more quickly, achieving excellent strengthening and toughening effects of the material. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 This is a test diagram of the mechanical properties of the TPU-Cu film material of the present invention;

[0024] Figure 2 This is a test diagram of the mechanical properties of the TPU-Mg film material of the present invention;

[0025] Figure 3 This is the original mechanical properties diagram of the TPU film material of the present invention;

[0026] Figure 4 This is a schematic diagram of the TPU-Mg film of the present invention;

[0027] Figure 5 Mg 2+ Schematic diagram of the principle of modified TPU material. DETAILED DESCRIPTION

[0028] The present invention is further described below in conjunction with the accompanying drawings:

[0029] Sources of reagents used in the present invention:

[0030]

[0031] A thermoplastic polyurethane material, wherein the thermoplastic polyurethane material is TPU-M, wherein M represents a cation, and the cation M is Mg 2+ 、Na + , Cu 2+ , K + One of them, the molecular formula of TPU is

[0032]

[0033] Wherein, the polymerization route of the TPU is as follows:

[0034]

[0035] The preparation method of TPU comprises the following steps: adding 1.125 parts by weight of isophorone diisocyanate IPDI, 1 part by weight of PEG400, and 1.5-2 parts by weight of DBTDL into a double-necked flask under a nitrogen environment, performing prepolymerization at 70-90° C. for 1-2 hours, adding 0.274 parts by weight of indole diol after the prepolymerization, and diluting with 4-24 parts by weight of DMF, the viscosity will increase rapidly after the addition of indole diol, and it is necessary to adjust the rotation speed and add 0.8-10 parts by weight of DMF, and continue the reaction at 70-90° C. for 3-4 hours, and obtain a TPU polymer solution after the polymerization is completed; wherein the molar feed ratio of IPDI:PEG400:indole diol is 2:1:1.

[0036] The synthetic route of the indolediol is as follows:

[0037]

[0038] The preparation method of the indolediol comprises the following steps:

[0039] (1) Tryptophan protection: accurately weigh 20 mmol of chlorosilane in a reaction bottle, heat to 100°C, add 20 mL of dichloromethane to dissolve completely, place in an ice bath, add a mixed solution of 20 mmol of imidazole and 30 mmol of tryptophan in dichloromethane dropwise at a rate of 3 seconds / drop, stir overnight at room temperature (20-25°C), then extract with brine and 50 mL of ethyl acetate to obtain a tryptophan protected product;

[0040] (2) Secondary protection: the tryptophan protected product was dissolved in 30 mL of DMF under ice bath conditions, NaH was added and stirred for 1 h, and 10 mL of a mixed solution of bromosilane and DMF was added dropwise, with the molar ratio of NaH to the tryptophan protected product being 1:1. The temperature was raised to 100°C and the reaction was carried out for 3.5 h. Water was added to the reaction flask until no bubbles were generated, and the reaction was carried out with water and 50 mL of ethyl acetate. The upper layer solution was removed, 5.0 g of anhydrous magnesium sulfate was added, and the mixture was allowed to stand overnight. After concentration, the mixture was purified by column chromatography to obtain the tryptophan secondary protected product. The developing solvent used for column purification was PE:EA=60:1+5% triethylamine.

[0041] (3) Deprotection: The second protection product of the tryptophan was dissolved in 20 mL of tetrahydrofuran, and then 3 mL of 1 mol / L tetrabutylammonium fluoride was added to react at room temperature for 1-2 h. After extraction with water and 50 mL of ethyl acetate, the mixture was purified by column chromatography and dried to finally obtain indolediol.

[0042] Example 1

[0043] Preparation of TPU: 0.9 g of isophorone diisocyanate IPDI (4 mmol), 0.8 g of PEG400 (2 mmol) and 1.5 g of DBTDL were added into a double-necked flask under nitrogen environment, and prepolymerized at 80°C for 1 h. After the prepolymerization, 0.2193 g of indolediol (2 mmol) was added and diluted with 20 mL of DMF. After adding indolediol, the viscosity increased rapidly and the rotation speed needed to be adjusted and 4 mL of DMF needed to be added. The reaction was continued at 90°C for 3 h to obtain a polymer solution.

[0044] Example 2

[0045] Preparation of TPU: 4.5 g of isophorone diisocyanate IPDI (20 mmol), 4.0 g of PEG400 (10 mmol) and 6.0 g of DBTDL were added into a double-necked flask under nitrogen environment, and prepolymerized at 80°C for 1.5 h. After the prepolymerization, 1.096 g of indolediol (10 mmol) was added and diluted with 60 mL of DMF. After adding indolediol, the viscosity increased rapidly and the rotation speed needed to be adjusted and 10 mL of DMF needed to be added. The reaction was continued at 90°C for 4 h to obtain a polymer solution.

[0046] Example 3

[0047] Preparation of TPU: 9.0g of isophorone diisocyanate IPDI (40mmol), 8.0g of PEG400 (20mmol) and 12.0g of DBTDL were added to a two-necked flask under nitrogen atmosphere, and prepolymerized at 80°C for 1-3h. After the prepolymerization, 2.1928g of indole diol (20mmol) was added and diluted with 90mL of DMF. After the addition of indole diol, the viscosity increased rapidly and the speed needed to be adjusted and 18mL of DMF was added. The reaction was continued at 0°C for 5h to obtain a polymer solution.

[0048] The polymer solution obtained after the polymerization in Example 1-3 is spread on the mold plate, put into an oven and dried at 80° C. for 12 hours to obtain a polymer film, namely a TPU film material.

[0049] Example 4

[0050] Preparation of TPU-Mg (0.1%) thin film material:

[0051] Take the TPU polymer solution obtained in any one of Examples 1-3 in a small glass bottle, and evenly disperse the accurately weighed MgCl2 in DMSO by ultrasonication. 2+ The addition amount is 0.1% of the molar amount of indole in the polymer, and is added to the polymer solution according to the molar ratio and ultrasonically mixed to obtain a TPU-Mg polymer solution; after ultrasonic homogenization, the polymer solution is poured into a mold plate, placed in an oven and dried at 80°C for 24 hours to remove the solvent, and after drying, the mold plate is taken out and cooled to room temperature, and the film is peeled off to obtain a TPU-Mg (0.1%) thin film material.

[0052] Example 5

[0053] Preparation of TPU-Mg (0.15%) film material:

[0054] Take the TPU polymer solution obtained in any one of Examples 1-3 in a small glass bottle, and evenly disperse the accurately weighed MgCl2 in DMSO by ultrasonication. 2+ The addition amount is 0.15% of the molar amount of indole in the polymer, and is added to the polymer solution according to the molar ratio and ultrasonically mixed to obtain a TPU-Mg polymer solution; after ultrasonic homogenization, the polymer solution is poured into a mold plate, placed in an oven and dried at 80°C for 24 hours to remove the solvent, and after drying, the mold plate is taken out and cooled to room temperature, and the film is peeled off to obtain a TPU-Mg (0.15%) thin film material.

[0055] Example 6

[0056] Preparation of TPU-Cu (0.1%) thin film material:

[0057] Take the TPU polymer solution obtained in any one of Examples 1-3 in a small glass bottle, and ultrasonically disperse the accurately weighed CuCl2 in DMSO. 2+ The addition amount is 0.1% of the molar amount of indole in the polymer, and is added to the polymer solution according to the molar ratio and ultrasonically mixed to obtain a TPU-Cu polymer solution; after ultrasonic homogenization, the polymer solution is poured into a mold plate, placed in an oven and dried at 80°C for 24 hours to remove the solvent, and after drying, the mold plate is taken out and cooled to room temperature, and the film is peeled off to obtain a TPU-Cu (0.1%) thin film material.

[0058] Example 7

[0059] Preparation of TPU-Cu (1%) thin film material:

[0060] Take the TPU polymer solution obtained in any one of Examples 1-3 in a small glass bottle, and ultrasonically disperse the accurately weighed CuCl2 in DMSO. 2+ The addition amount is 1% of the molar amount of indole in the polymer, and is added to the polymer solution according to the molar ratio and ultrasonically mixed to obtain a TPU-Cu polymer solution; after ultrasonic homogenization, the polymer solution is poured into a mold plate, placed in an oven and dried at 80°C for 24 hours to remove the solvent, and after drying, the mold plate is taken out and cooled to room temperature, and the film is peeled off to obtain a TPU-Cu (1%) thin film material.

[0061] The mechanical properties of the TPU-M polymer film material and the TPU film material obtained in Examples 4-7 were tested. The mechanical properties of the film were tested using an electronic universal testing machine model E44.104, the sensor was selected to be 50N, and the test sample was a rectangular film of 15mm×40mm with a thickness of about 0.2mm. Before the test, the length, width, and thickness of the sample were accurately measured with a vernier caliper and a thickness gauge. The test conditions were a tensile test experiment at a rate of 20mm / min at room temperature.

[0062] As the instruction manual Figure 1 and 2 As shown, the test results show that when Mg 2+ When the addition amount is 0.1%, the performance is the best, the mechanical strength is 30.8MPa, and the elongation at break is 486%. 2+ When the addition amount is 1%, the mechanical strength is 23.1MPa and the elongation at break can reach 524%. It can be seen from the data that the material obtained by the present invention has excellent mechanical properties.

[0063] As attached Figure 5As shown, the principle of the material performance enhancement of the present invention is as follows: dynamic supramolecular non-covalent bonds such as hydrogen bonds, metal coordination bonds, etc. not only dissipate energy during the fracture and recombination process but also ensure the integrity of the network, and bear the intermolecular stress transmission, effectively preventing the loss of mechanical properties before the macroscopic fracture of the polymer material occurs, showing a significant enhancement and toughening effect. The cation-π interaction is considered to be a new type of non-covalent interaction, which has a strong force and is widely present in biological systems. It plays a very important role in many aspects such as molecular recognition, the structure and function of proteins and nucleic acids. The essence of the cation-π interaction is the interaction between positively charged cations and molecules or compounds containing π electron clouds. The indole ring is an electron-rich aromatic ring. When the cation is close to the π electron cloud, it is easier to form a stable cation-π interaction force. Indole diol and cationic functional groups are introduced into the polyurethane skeleton, and the cation-π interaction between polymer chains can be successfully established, realizing the dynamic cross-linking of polymer chains. Metal ions act as cross-linking points between polymer chains. Compared with other supramolecular "point-to-point" dynamic bonds such as hydrogen bonds and metal coordination bonds, cation-π is a "point-to-face" interaction. The formation and construction range of this force is expanded, the construction is simpler and more convenient, and the polymer chains can be cross-linked more quickly, achieving excellent reinforcement and toughening effects of the material.

[0064] The invention discloses an application of a thermoplastic polyurethane material. The TPU-M polymer obtained by the invention is pre-dried and then extruded and granulated, and can be used as a cable sheath material.

[0065] The processing method of polyurethane raw materials for sheath material is as follows:

[0066] 1. Pre-drying

[0067] The polyurethane polymer raw material is pre-dried at 85° C. for about 3-4 hours.

[0068] 2. Recommended processing temperature for extrusion granulation:

[0069]

[0070] In summary, the above are only preferred embodiments of the present invention and are not intended to limit the scope of implementation of the present invention. All equivalent changes and modifications to the shapes, structures, features and spirits described in the claims of the present invention should be included in the scope of the claims of the present invention.

Claims

1. A thermoplastic polyurethane material, Features: The thermoplastic polyurethane material is TPU-M, wherein M represents a cation, and the molecular formula of TPU is 2. A method for preparing a thermoplastic polyurethane material, Features: The polymerization route of the TPU is as follows: The preparation method of TPU comprises the following steps: adding isophorone diisocyanate IPDI, PEG400 and DBTDL into a double-necked flask under a nitrogen environment, performing prepolymerization at 70-90° C. for 1-2 hours, adding indole diol after the prepolymerization, diluting with DMF, the viscosity increases rapidly after the addition of indole diol, adjusting the rotation speed and adding DMF, continuing the reaction at 70-90° C. for 3-4 hours, and obtaining a TPU polymer solution after the polymerization is completed; wherein the molar feed ratio of IPDI:PEG400:indole diol is 2:1:1; The preparation method of TPU-M comprises the following steps: taking a TPU polymer solution in a small glass bottle, uniformly dispersing the chloride corresponding to the accurately weighed cation M in DMSO by ultrasonic dispersion, wherein the amount of the cation M added is 0%-1% of the molar amount of indole in the polymer, and adding the cation M to the polymer solution according to the molar ratio and uniformly mixing by ultrasonic dispersion to obtain a TPU-M polymer solution; after uniform ultrasonic dispersion, pouring the polymer solution into a mold plate, placing the solution in an oven at 80° C. and drying for 24 hours to remove the solvent, taking out the mold plate after drying, cooling it to room temperature, and peeling off the film to obtain a TPU-M film material; The synthetic route of the indolediol is as follows: The preparation method of the indolediol comprises the following steps: (1) Tryptophan protection: Weigh chlorosilane in a reaction bottle, heat to 90-120°C, add dichloromethane to completely dissolve, then cool on ice, add a mixed solution of imidazole and tryptophan in dichloromethane dropwise at a rate of 1-3 seconds / drop, stir overnight at room temperature of 20-25°C, then extract with brine and ethyl acetate to obtain a tryptophan protected product; The molar ratio of chlorosilane: tryptophan: imidazole is 1:1:1.5-2.0; (2) Secondary protection: dissolve the tryptophan protected product in DMF under ice bath conditions, add NaH and stir for 1-1.5h, then drop a mixed solution of bromosilane and DMF, heat to 90-110°C and react for 3-4h, add water to the reaction flask until no bubbles are generated, extract with water and ethyl acetate, remove the upper layer solution, add anhydrous magnesium sulfate and let stand overnight, then concentrate and purify by column to obtain the tryptophan secondary protected product, the developing solvent for column is PE:EA=60:1 and 5% triethylamine; (3) Deprotection: The second protection product of the tryptophan was dissolved in tetrahydrofuran and then added with tetrabutylammonium fluoride to react at room temperature for 1-2 hours. After extraction with water and ethyl acetate, the mixture was purified by column chromatography and dried to finally obtain indolediol.

3. A method for preparing a thermoplastic polyurethane material according to claim 2, Features: The cation M is Mg 2+ 、Na + , Cu 2+ , K + One of them.

4. A method for preparing a thermoplastic polyurethane material according to claim 2, Features: The preparation method of TPU comprises the following steps: adding 1.125 parts by weight of isophorone diisocyanate IPDI, 1 part by weight of PEG400, and 1.5-2 parts by weight of DBTDL into a double-necked flask under a nitrogen environment, performing prepolymerization at 70-90° C. for 1-2 hours, adding 0.274 parts by weight of indole diol after the prepolymerization, diluting with 4-24 parts by weight of DMF, the viscosity increases rapidly after the addition of indole diol, and the rotation speed needs to be adjusted and 0.8-10 parts by weight of DMF needs to be added, and the reaction is continued at 70-90° C. for 3-4 hours, and a TPU polymer solution is obtained after the polymerization is completed; wherein the molar feed ratio of IPDI:PEG400:indole diol is 2:1:

1.

5. Application of a thermoplastic polyurethane material, Features: The TPU-M polymer is pre-dried and extruded into granules for use as a cable sheath material.

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