Thermoplastic polyurethane, alloy material, preparation method and application

Abstract

The invention discloses thermoplastic polyurethane, an alloy material, a preparation method and application, relates to the field of thermoplastic elastomers, and solves the problems that low hardness and high strength of an alloy material are difficult to consider and the product performance stability is poor. The thermoplastic polyurethane is prepared from the following raw materials in percentage by mass: 5%-30% of polyester polyol with a main chain containing a siloxane structure, 50%-80% of polyol A, 10%-40% of diisocyanate and 1.5%-20% of a chain extender, the preparation method of the polyester polyol with the main chain containing the siloxane structure comprises the following steps: S1, preparing siloxane-containing diol; and S2, mixing the siloxane-containing diol with diacid, and carrying out polymerization reaction. The low-hardness and stable-performance thermoplastic polyurethane elastomer containing the siloxane structure is obtained, and an alloy material prepared from thermoplastic polyurethane subsequently has excellent tensile strength while meeting the requirement for low hardness and meanwhile has good performance stability.

Description

Technical Field

[0001] This invention relates to the field of thermoplastic elastomers, specifically to a thermoplastic polyurethane, alloy material, preparation method, and application. Background Technology

[0002] Soft thermoplastic elastomers (TPEs) require a Shore hardness in the range of 30A to 60A. Common TPE materials within this hardness range, such as polyolefin elastomers (POE) and styrene-ethylene-butene-styrene block copolymers (SEBS), often fail to achieve satisfactory tensile strength. With increasingly complex product varieties and increasingly demanding customer requirements, relying solely on the bulk material is no longer sufficient. Thermoplastic polyurethane elastomers (TPUs), due to their unique microphase-separated microstructure, maintain good elasticity, abrasion resistance, and high tensile strength over a wide hardness range, leading to their increasingly widespread applications in recent years. Blending and modifying TPUs with the aforementioned polyolefin elastomers to prepare polymer alloys holds promise for achieving complementary properties. However, most commercially available TPU products currently on the market have a hardness above 60A.

[0003] Introducing a large number of flexible segments into TPU can reduce hardness to some extent, such as by introducing compliant siloxane segments. However, simply blending polysiloxane with TPU or grafting polysiloxane segments onto TPU has limited effect on improving the flexibility of TPU. The polarity of polysiloxane and TPU is incompatible, which can easily lead to poor performance stability of the resulting product. Summary of the Invention

[0004] This invention provides a thermoplastic polyurethane, alloy material, preparation method, and application to solve the problems of low hardness and high strength, as well as poor product performance stability in existing alloy materials.

[0005] In a first aspect, this application provides a thermoplastic polyurethane comprising, by weight percentage, the following raw materials: The main chain contains 5%~30% polyester polyol with siloxane structure, 50%~80% polyol A, 10%~40% diisocyanate, and 1.5%~20% chain extender; The preparation method of the polyester polyol containing a siloxane structure in the main chain includes: S1. Prepare siloxane diols by reacting diene-containing siloxanes with alcohols containing monothiols. S2. The siloxane diol and diacid are mixed and polymerized.

[0006] In one possible implementation, S1 includes: mixing the diene-containing siloxane, the monothiol-containing alcohol, and the photoinitiator, and reacting them under ultraviolet light irradiation to obtain the siloxane-containing diol; In one possible implementation, the molar ratio of the dienyl-containing siloxane to the monothiol-containing alcohol is (1~3):(2~10). In one possible implementation, the photoinitiator is 0.1-10% of the sum of the mass of the dienyl-containing siloxane and the monothiol-containing alcohol; In one possible implementation, the photoinitiator comprises one or more of 2,2-dimethoxyphenylacetophenone (DMPA), 2-hydroxy-2-methyl-1-phenylpropanone, 1-hydroxycyclohexylphenyl methyl ketone, and (2,4,6-trimethylbenzoyl)diphenylphosphine oxide; In one possible implementation, the reaction is carried out under ultraviolet light irradiation for 0.5 to 3 hours; In one possible implementation, the dienyl-containing siloxane includes one or more of tetramethyldivinyldisiloxane and diallyltetramethyldisiloxane; In one possible implementation, the alcohol containing a monothiol includes one or more of 2-mercaptoethanol, 3-mercapto-1-propanol, 4-mercapto-1-butanol, and 5-mercapto-1-pentanol.

[0007] In one possible implementation, S2 further includes the addition of diol A; Optionally, the molar ratio of siloxane diol to diol A is (1~10):(0~9). Optionally, the molar ratio of the sum of the molar amounts of siloxane diol and diol A to the molar amount of diacid is (1~5):(1~3); the molar ratio of the sum of the molar amounts of siloxane diol and diol A to the molar amount of diacid is >1.

[0008] Optionally, the diol A includes one or more of ethylene glycol, 1,2-propanediol, 1,4-butanediol, diethylene glycol, and neopentyl glycol; In one possible implementation, the polymerization reaction is carried out at a temperature of 150-250°C for a duration of 8-12 hours. In one possible implementation, the dicarboxylic acid includes one or more of succinic acid, glutaric acid, adipic acid, sebacic acid, terephthalic acid, and isophthalic acid; In one possible implementation, the polymerization reaction is carried out in the presence of a catalyst, which includes one or more of titanium, tin, and antimony catalysts. Optionally, the titanium catalyst includes one or more of tetrabutyl titanate, tetraisopropyl titanate, and titanium dioxide; Optionally, the tin-based catalyst includes one or more of tetrabutyl titanate, tetraisopropyl titanate, and titanium dioxide; Optionally, the antimony catalyst includes one or more of antimony acetate, antimony trioxide, and antimony glycolate.

[0009] In one possible implementation, the polyol A includes one or more of polyester polyols, polyether polyols, polycarbonate polyols, and polycaprolactone polyols. In one possible embodiment, the diisocyanate comprises one or more of the following: toluene diisocyanate, diphenylmethane diisocyanate, isophorone diisocyanate, hexamethylene diisocyanate, dicyclohexylmethane diisocyanate, terephthalic diisocyanate, naphthalene diisocyanate, 1,4-cyclohexane diisocyanate, phenylenediamine diisocyanate, cyclohexane diisocyanate, trimethyl-1,6-hexamethylene diisocyanate, tetramethyl-methylene-phenylenediamine diisocyanate, norbornene diisocyanate, dimethylbiphenyl diisocyanate, methylcyclohexyl diisocyanate, dimethyldiphenylmethane diisocyanate, and lysine diisocyanate. In one possible implementation, the chain extender includes one or more of ethylene glycol, 1,4-butanediol, diethylene glycol, 1,6-hexanediol, 1,3-propanediol, dipropylene glycol, neopentyl glycol, 1,5-pentanediol, and 1,4-cyclohexanediamine.

[0010] In one possible implementation, the thermoplastic polyurethane has a Shore hardness of 40A-60A and a molecular weight of 15-30W.

[0011] Secondly, this application provides a method for preparing the aforementioned thermoplastic polyurethane, comprising the following steps: The polyester polyol with a siloxane structure in the main chain, polyol A, and diisocyanate are mixed and subjected to a prepolymerization reaction to obtain an isocyanate-terminated prepolymer. The prepolymer is mixed with a chain extender and then cured to obtain the thermoplastic polyurethane; In one possible implementation, the prepolymerization reaction is carried out under the condition of heating at 70-100°C for 2-6 hours; In one possible implementation, the curing conditions are heating at 80°C to 100°C for 8 to 16 hours.

[0012] Thirdly, this application provides a low-hardness, high-strength alloy material, comprising the following components by mass percentage: The thermoplastic polyurethane or thermoplastic polyurethane prepared according to the preparation method comprises 50-90%, polyolefin elastomer 0-30%, compatibilizer 0-10%, and plasticizer 10-30%.

[0013] In one possible implementation, the polyolefin elastomer includes one or more of ethylene-butene copolymers, ethylene-hexene copolymers, and ethylene-octene copolymers; In one possible implementation, the polyolefin elastomer has a Shore hardness of 40A to 70A; In one possible implementation, the compatibilizer is a PEO graft; In one possible implementation, the compatibilizer comprises one or more of maleic anhydride-grafted POE, amino-grafted POE, glycidyl methacrylate-grafted POE, hydroxyl-grafted POE, carboxylic acid-grafted POE, or imide-grafted POE. Optionally, the grafting rate of the compatibilizer is 0.3~3wt%; In one possible implementation, the plasticizer comprises one or more of propylene glycol dibenzoate, dipropylene glycol dibenzoate, ethylene glycol dibenzoate, diethylene glycol dibenzoate, diethylene glycol dibenzoate, neopentyl glycol dibenzoate, and pentylene glycol dibenzoate. In one possible implementation, the thermoplastic polyurethane comprises 50-85%; In one possible implementation, the polyolefin elastomer comprises 10-20%; In one possible implementation, the compatibilizer is 5-8%; In one possible implementation, the plasticizer is 15-30%.

[0014] Fourthly, this application provides a method for preparing the low-hardness, high-strength alloy material, comprising the following steps: mixing raw materials and then melt-extruding them using a twin-screw extruder to obtain the low-hardness, high-strength alloy material; Optionally, the step of mixing the raw materials includes: first mixing the thermoplastic polyurethane with the plasticizer, and then mixing it with the polyolefin elastomer and compatibilizer; Optionally, the temperature of the melt extrusion is 100~180℃ and the screw speed is 200~450rpm.

[0015] In one possible implementation, the preparation method of the alloy material includes the following steps: (1) weighing the thermoplastic polyurethane elastomer and plasticizer according to the weight ratio and pre-mixing them, and heating them at 60~100℃ to promote the absorption of the plasticizer; (2) weighing the remaining raw materials according to the weight ratio and mixing them with the materials mixed in step (1) in a mixer; (3) feeding the raw materials mixed in step (2) into the feeding hopper of a twin-screw extruder, and granulating them after melt extrusion. The processing technology is as follows: extrusion temperature 100-180℃, screw speed: 200-450rpm.

[0016] Fifthly, this application provides an application of the low-hardness high-strength alloy material or the low-hardness high-strength alloy material prepared according to the preparation method in films, sheets, extruded pipes, and extruded cables.

[0017] The technical solution of this invention has the following advantages: 1. The thermoplastic polyurethane provided by the present invention comprises, by weight percentage, the following raw materials: 5%~30% polyester polyol with a main chain containing a siloxane structure, 50%~80% polyol A, 10%~40% diisocyanate, and 1.5%~20% chain extender; the preparation method of the polyester polyol with a main chain containing a siloxane structure includes: S1, reacting a dienyl-containing siloxane with an alcohol containing a monothiol to prepare a siloxane-containing diol; S2, mixing the siloxane-containing diol with a diacid and carrying out a polymerization reaction.

[0018] This application uses siloxane-containing compounds as monomers and embeds them into the main chain of polyester polyols through a chemical reaction. This achieves uniform and stable embedding of siloxane segments into the TPU soft segment main chain at the molecular level, resulting in a low-hardness, high-performance thermoplastic polyurethane elastomer with a siloxane-containing structure. As a result, alloy materials subsequently made using this thermoplastic polyurethane exhibit excellent tensile strength while meeting the requirement of low hardness, and also possess good performance stability.

[0019] 2. The low-hardness, high-strength alloy material provided by the present invention comprises the following components by mass percentage: 60-90% thermoplastic polyurethane, 0-30% polyolefin elastomer (POE), 0-10% compatibilizer, and 10-30% plasticizer.

[0020] The synergistic optimization of the alloy material formulation in this application, along with the improved compatibility and strong interfacial bonding between POE and TPU, enables the material to simultaneously possess low hardness, high strength, and good performance stability and elongation at break. Furthermore, the partial replacement of TPU with POE effectively reduces raw material costs while maintaining the overall performance of the material, significantly enhancing the product's market competitiveness. Detailed Implementation

[0021] The following embodiments are provided to better understand the present invention, but the following embodiments do not constitute a limitation on the content and scope of protection of the present invention. Any product that is the same as or similar to the present invention, derived by any person under the guidance of the present invention or by combining the features of the present invention with other prior art, falls within the scope of protection of the present invention.

[0022] Unless otherwise specified, the experimental steps or conditions in the examples were performed in accordance with conventional experimental procedures and conditions in the art. Reagents or instruments whose manufacturers are not specified are all commercially available products.

[0023] Raw material source:

[0024] Example 1 This embodiment provides a method for preparing thermoplastic polyurethane, including the following steps: (1) Preparation of polyester polyols with siloxane structures in the main chain: First, weigh 55.9 g of tetramethyldivinyldisiloxane and 58.6 g of 2-mercaptoethanol. Then, add 0.5% DMPA (the sum of the mass of tetramethyldivinyldisiloxane and 2-mercaptoethanol) as a photoinitiator. Stir the reaction solution under ultraviolet light (365 nm) for 30 minutes to initiate a "thiol-ene" click reaction. Add 200 mL of toluene to the resulting mixture and wash with water 5-6 times. Then concentrate under reduced pressure to obtain a siloxane diol.

[0025] Next, 10 kg of the siloxane-containing diol prepared above was mixed evenly with 10 kg of 1,4-butanediol and 18.5 kg of adipic acid, and the mixture was heated to 150°C and reacted for 1 hour. The temperature was then increased to 180°C and the mixture was kept at a constant temperature for 1.5 hours. Finally, the temperature was raised to 210°C, and when the acid value was less than 10 mg KOH / g, 3.77 g of tetrabutyl titanate was added and the mixture was reacted for 1 hour. The vacuum was then turned on to -0.0090 MPa to remove the water and excess diol from the reaction product. The mixture was then cooled and discharged to obtain a polyester polyol with a siloxane-containing main chain.

[0026] (2) The raw materials of thermoplastic polyurethane include, by mass, 8 parts of polyester polyol with siloxane structure in the main chain obtained in step (1); 74 parts of polyol A (PBA); 16 parts of diisocyanate (diphenylmethane diisocyanate); and 2 parts of chain extender (1,4-butanediol).

[0027] Polyester polyols with siloxane structures in the main chain, polyol A, and diisocyanate were mixed and subjected to a prepolymerization reaction to obtain an isocyanate-terminated prepolymer. The prepolymerization reaction was carried out under the condition of heating at 80°C for 3 hours.

[0028] The prepolymer was mixed with a chain extender to obtain a mixture, which was then cured to obtain thermoplastic polyurethane. The curing conditions were heating at 90°C for 10 hours.

[0029] This embodiment also provides a thermoplastic low-hardness high-strength alloy material, the raw materials of which include, by mass parts: In this embodiment, 80 parts of thermoplastic polyurethane were prepared; 20 parts of ethylene-butene copolymer; 8 parts compatibilizer 25 parts plasticizer.

[0030] The preparation method of thermoplastic low-hardness high-strength alloy material includes: first, mixing thermoplastic polyurethane and plasticizer according to the weight ratio, and heating at 80℃ to promote the absorption of plasticizer; then, mixing it with the remaining raw materials in a low-temperature mixer according to the weight ratio; then, feeding the pre-mixed raw materials into the feeding hopper of a twin-screw extruder, and performing melt extrusion and granulation. The processing technology is as follows: extrusion temperature 140℃, screw speed: 350rpm.

[0031] Example 2 The preparation method of thermoplastic polyurethane in this embodiment is the same as that in Example 1.

[0032] The thermoplastic low-hardness high-strength alloy material in this embodiment comprises, by weight, the following raw materials: The thermoplastic polyurethane prepared in this embodiment: 80 parts; Ethylene-butene copolymer: 20 parts; Compatibilizer: 8 parts Plasticizer: 43 parts.

[0033] The preparation method of thermoplastic low-hardness high-strength alloy material includes: first, mixing thermoplastic polyurethane and plasticizer according to weight ratio, and heating to promote the absorption of plasticizer; then, mixing it with the remaining raw materials in a low-temperature mixer according to weight ratio; then, feeding the pre-mixed raw materials into the feeding hopper of a twin-screw extruder, and performing melt extrusion and granulation. The processing technology is as follows: extrusion temperature 140℃, screw speed: 350rpm.

[0034] Example 3 This embodiment provides a method for preparing thermoplastic polyurethane, including the following steps: (1) Preparation of polyester polyols with siloxane structure in the main chain: same as in Example 1.

[0035] (2) The raw materials of thermoplastic polyurethane include, by mass, 16 parts of polyester polyol with siloxane structure in the main chain obtained in step (1); 66 parts of polyol A (PBA); 16 parts of diisocyanate (diphenylmethane diisocyanate); and 2 parts of chain extender (1,4-butanediol).

[0036] Polyester polyols with siloxane structures in the main chain, polyol A, and diisocyanate are mixed and subjected to a prepolymerization reaction to obtain isocyanate-terminated prepolymers. The prepolymerization reaction is carried out under the condition of heating at 70~100℃ for 2~6 hours.

[0037] Thermoplastic polyurethane is prepared by aging a mixture of prepolymer and chain extender under the following conditions: heating at 80℃~100℃ for 8~16h.

[0038] The thermoplastic low-hardness high-strength alloy material in this embodiment is basically the same as that in Example 1, except that the thermoplastic polyurethane used is the one prepared in Example 3.

[0039] Example 4 The preparation method of thermoplastic polyurethane in this embodiment is the same as that in Example 3.

[0040] This embodiment also provides a thermoplastic low-hardness high-strength alloy material, the raw materials of which include, by mass parts: In this embodiment, 80 parts of thermoplastic polyurethane, 20 parts of ethylene-butene copolymer, 8 parts of compatibilizer, and 43 parts of plasticizer were prepared.

[0041] The preparation method of thermoplastic low-hardness high-strength alloy material includes: first, mixing thermoplastic polyurethane and plasticizer according to weight ratio, and heating to promote the absorption of plasticizer; then, mixing it with the remaining raw materials in a low-temperature mixer according to weight ratio; then, feeding the pre-mixed raw materials into the feeding hopper of a twin-screw extruder, and performing melt extrusion and granulation. The processing technology is as follows: extrusion temperature 140℃, screw speed: 350rpm.

[0042] Example 5 This embodiment provides a method for preparing thermoplastic polyurethane, including the following steps: (1) Preparation of polyester polyols with siloxane structures in the main chain: First, weigh 55.9 g of tetramethyldivinyldisiloxane and 58.6 g of 2-mercaptoethanol. Then, add 0.5% DMPA (the sum of the mass of tetramethyldivinyldisiloxane and 2-mercaptoethanol) as a photoinitiator. Stir the reaction mixture under UV light for 30 minutes to initiate a "thiol-ene" click reaction. Add 200 mL of toluene to the resulting mixture and wash with water 5-6 times. Then concentrate under reduced pressure to obtain a siloxane diol.

[0043] Next, 10 kg of the siloxane-containing diol prepared above was mixed evenly with 10 kg of 1,4-butanediol and 18.5 kg of adipic acid, and the mixture was heated to 150°C and reacted for 1 hour. The temperature was then increased to 180°C and the mixture was kept at a constant temperature for 1.5 hours. Finally, the temperature was raised to 230°C, and when the acid value was less than 10 mg KOH / g, 3.77 g of tetrabutyl titanate was added and the mixture was reacted for 1 hour. The vacuum was then turned on to -0.0090 MPa to remove the water and excess diol from the reaction product. The mixture was then cooled and discharged to obtain a polyester polyol with a siloxane-containing main chain.

[0044] (2) The raw materials of thermoplastic polyurethane include, by mass, 16 parts of polyester polyol with siloxane structure in the main chain obtained in step (1); 66 parts of PBA; 16 parts of diisocyanate (diphenylmethane diisocyanate); and 2 parts of chain extender (1,4-butanediol).

[0045] Polyester polyol with a main chain containing siloxane structure, polyol A, and diisocyanate were mixed and subjected to a prepolymerization reaction to obtain an isocyanate-terminated prepolymer. The prepolymerization reaction was carried out under the condition of heating at 100°C for 2 hours.

[0046] The prepolymer was mixed with a chain extender to obtain a mixture, which was then cured to obtain thermoplastic polyurethane. The curing conditions were heating at 80°C for 16 hours.

[0047] This embodiment also provides a thermoplastic low-hardness high-strength alloy material, the raw materials of which include, by mass parts: The thermoplastic polyurethane prepared in this embodiment: 70 parts; Ethylene-butene copolymer: 30 parts; Compatibilizer: 8 parts; Plasticizer: 25 parts.

[0048] The preparation method of thermoplastic low-hardness high-strength alloy material includes: first, mixing thermoplastic polyurethane and plasticizer according to weight ratio, and heating to promote the absorption of plasticizer; then, mixing it with the remaining raw materials in a low-temperature mixer according to weight ratio; then, feeding the pre-mixed raw materials into the feeding hopper of a twin-screw extruder, and performing melt extrusion and granulation. The processing technology is as follows: extrusion temperature 140℃, screw speed: 350rpm.

[0049] Example 6 This embodiment provides a method for preparing thermoplastic polyurethane, including the following steps: (1) Preparation of polyester polyols with siloxane structures in the main chain: First, weigh 55.9 g of tetramethyldivinyldisiloxane and 58.6 g of 2-mercaptoethanol. Then, add 0.5% DMPA (the sum of the mass of tetramethyldivinyldisiloxane and 2-mercaptoethanol) as a photoinitiator. Stir the reaction mixture under ultraviolet light for 30 minutes to initiate a "thiol-ene" click reaction. Add 200 mL of toluene to the resulting mixture and wash with water 5-6 times. Subsequently, concentrate under reduced pressure to obtain a siloxane diol.

[0050] Next, 10 kg of the siloxane-containing diol prepared above was mixed evenly with 5 kg of 1,4-butanediol and 11.2 kg of adipic acid, and the mixture was heated to 150°C and reacted for 1 hour. The temperature was then increased to 180°C and the mixture was kept at a constant temperature for 1.5 hours. Finally, the temperature was raised to 210°C, and when the acid value was less than 10 mg KOH / g, 3.77 g of tetrabutyl titanate was added and the mixture was reacted for 1 hour. The vacuum was then turned on to -0.0090 MPa to remove the water and excess diol from the reaction product. The mixture was then cooled and discharged to obtain a polyester polyol with a siloxane-containing main chain.

[0051] (2) The raw materials of thermoplastic polyurethane include, by mass, 24 parts of polyester polyol with siloxane structure in the main chain obtained in step (1); 58 parts of polyol A (PBA); 16 parts of diisocyanate (diphenylmethane diisocyanate); and 2 parts of chain extender (1,4-butanediol).

[0052] Polyester polyol with a main chain containing siloxane structure, polyol A, and diisocyanate were mixed and subjected to a prepolymerization reaction to obtain an isocyanate-terminated prepolymer; the prepolymerization reaction was carried out under the condition of heating at 70°C for 6 hours.

[0053] The prepolymer was mixed with a chain extender to obtain a mixture, which was then cured to obtain thermoplastic polyurethane. The curing conditions were heating at 100°C for 8 hours.

[0054] The thermoplastic low-hardness high-strength alloy material in this embodiment is basically the same as that in Example 1, except that the thermoplastic polyurethane used is the one obtained in Example 6.

[0055] Comparative Example 1 This comparative example provides a method for preparing thermoplastic polyurethane, which is basically the same as that in Example 1, except that a polyester polyol with a siloxane structure in the main chain was not prepared. The raw materials include, by mass, 82 parts of polyol A (PBA); 16 parts of diisocyanate (diphenylmethane diisocyanate); and 2 parts of chain extender (1,4-butanediol).

[0056] The alloy material used in this comparative example is basically the same as that in Example 1, except that the thermoplastic polyurethane used is the same as that prepared in Comparative Example 1.

[0057] Comparative Example 2 The preparation method of the thermoplastic polyurethane in this comparative example is the same as that in Comparative Example 1.

[0058] The raw materials for this comparative alloy material include, by mass parts: The thermoplastic polyurethane prepared in this comparative example: 72 parts; 8 parts of hydroxypropyl-terminated polysiloxane; Ethylene-butene copolymer: 20 parts; Compatibilizer: 8 parts Plasticizer: 25 parts.

[0059] Test case Hardness testing was conducted according to ASTM D2240 standard; light transmittance testing samples were all 0.3mm cast films, and tensile strength and elongation at break testing were conducted according to ASTM D412 standard.

[0060] Stability testing: Each example and comparative example was repeated three times. The standard deviation of the tensile strength of the three experimental samples was calculated to measure the stability of the material properties.

[0061] Formula for calculating standard deviation:

[0062] Where σ is the standard deviation of the sample, x i is the tensile strength of the sample obtained in the i-th test, and μ is the average tensile strength of the three tensile tests.

[0063] The test results are shown in Table 1.

[0064] Table 1

[0065] As shown in Table 1, the Shore hardness of the alloy material of this application is ≤42A, the tensile strength is ≥12MPa, and the standard deviation of the tensile strength is ≤0.8. That is, the alloy material obtained in this application simultaneously possesses low Shore hardness, high tensile strength, and good performance stability. Furthermore, the elongation at break of the alloy material of this application is ≥400%, and the light transmittance is ≥84%.

[0066] Obviously, the above embodiments are merely illustrative examples for clear explanation and are not intended to limit the implementation. Those skilled in the art will recognize that other variations or modifications can be made based on the above description. It is neither necessary nor possible to exhaustively list all possible implementations here. However, obvious variations or modifications derived therefrom are still within the scope of protection of this invention.

Claims

1. A thermoplastic polyurethane, characterized in that, The ingredients include the following raw materials, expressed as a percentage by weight: The main chain contains 5%~30% polyester polyol with siloxane structure, 50%~80% polyol A, 10%~40% diisocyanate, and 1.5%~20% chain extender; The preparation method of the polyester polyol containing a siloxane structure in the main chain includes: S1. Prepare siloxane diols by reacting diene-containing siloxanes with alcohols containing monothiols. S2. The siloxane diol and diacid are mixed and polymerized.

2. The thermoplastic polyurethane according to claim 1, characterized in that, S1 includes: mixing the diene-containing siloxane, the alcohol containing a monothiol, and a photoinitiator, and reacting them under ultraviolet light irradiation to obtain the siloxane-containing diol; Optionally, the molar ratio of the dienyl-containing siloxane to the monothiol-containing alcohol is (1~3):(2~10). Optionally, the mass of the photoinitiator is 0.1-10% of the sum of the mass of the dienyl-containing siloxane and the monothiol-containing alcohol; Optionally, the photoinitiator includes one or more of 2,2-dimethoxy-phenylacetophenone, 2-hydroxy-2-methyl-1-phenylpropanone, 1-hydroxycyclohexylphenyl methyl ketone, and (2,4,6-trimethylbenzoyl)diphenylphosphine oxide; Optionally, the reaction can be carried out under ultraviolet light irradiation for 0.5 to 3 hours; Optionally, the dienyl-containing siloxane includes one or more of tetramethyldivinyldisiloxane and diallyltetramethyldisiloxane; Optionally, the alcohol containing a monothiol includes one or more of 2-mercaptoethanol, 3-mercapto-1-propanol, 4-mercapto-1-butanol, and 5-mercapto-1-pentanol.

3. The thermoplastic polyurethane according to claim 1, characterized in that, S2 satisfies at least one of the following conditions: (1) S2 further includes the addition of diol A; Optionally, the molar ratio of siloxane diol to diol A is (1~10):(0~9). Optionally, the molar ratio of the sum of the molar amounts of siloxane diol and diol A to the molar ratio of the diacid is (1~5):(1~3). Optionally, the diol A includes one or more of ethylene glycol, 1,2-propanediol, 1,4-butanediol, diethylene glycol, and neopentyl glycol; (2) The polymerization reaction is carried out at a temperature of 150~250℃ for 8~12h; (3) The dicarboxylic acid includes one or more of succinic acid, glutaric acid, adipic acid, sebacic acid, terephthalic acid, and isophthalic acid; (4) The polymerization reaction is carried out in the presence of a catalyst, which includes one or more of titanium catalysts, tin catalysts and antimony catalysts; Optionally, the titanium catalyst includes one or more of tetrabutyl titanate, tetraisopropyl titanate, and titanium dioxide; Optionally, the tin-based catalyst includes one or more of tetrabutyl titanate, tetraisopropyl titanate, and titanium dioxide; Optionally, the antimony catalyst includes one or more of antimony acetate, antimony trioxide, and antimony glycolate.

4. The thermoplastic polyurethane according to any one of claims 1-3, characterized in that, At least one of the following conditions must be met: (1) The polyol A includes one or more of polyester polyols, polyether polyols, polycarbonate polyols and polycaprolactone polyols; (2) The diisocyanate includes one or more of the following: toluene diisocyanate, diphenylmethane diisocyanate, isophorone diisocyanate, hexamethylene diisocyanate, dicyclohexylmethane diisocyanate, terephthalic diisocyanate, naphthalene diisocyanate, 1,4-cyclohexane diisocyanate, phenylmethylene diisocyanate, cyclohexane diisocyanate, trimethyl-1,6-hexamethylene diisocyanate, tetramethyl-isophthalic diisocyanate, norbornene diisocyanate, dimethyl biphenyl diisocyanate, methylcyclohexyl diisocyanate, dimethyl diphenylmethane diisocyanate, and lysine diisocyanate. (3) The chain extender includes one or more of ethylene glycol, 1,4-butanediol, diethylene glycol, 1,6-hexanediol, 1,3-propanediol, dipropylene glycol, neopentyl glycol, 1,5-pentanediol, and 1,4-cyclohexanediamine.

5. A method for preparing the thermoplastic polyurethane according to any one of claims 1-4, characterized in that, Includes the following steps: The polyester polyol with a siloxane structure in the main chain, polyol A, and diisocyanate are mixed and subjected to a prepolymerization reaction to obtain an isocyanate-terminated prepolymer. The prepolymer is mixed with a chain extender and then cured to obtain the thermoplastic polyurethane; Optionally, the prepolymerization reaction is performed under the condition of heating at 70~100℃ for 2~6 hours; Optionally, the curing conditions are heating at 80℃~100℃ for 8~16 hours.

6. A low-hardness, high-strength alloy material, characterized in that, In terms of mass percentage, Includes the following components: The thermoplastic polyurethane as described in any one of claims 1-4 or the thermoplastic polyurethane prepared by the preparation method according to claim 5, comprising 50-90% of the thermoplastic polyurethane, 0-30% of the polyolefin elastomer, 0-10% of the compatibilizer, and 10-30% of the plasticizer.

7. The low-hardness, high-strength alloy material according to claim 6, characterized in that, At least one of the following conditions must be met: (1) The polyolefin elastomer includes one or more of ethylene-butene copolymer, ethylene-hexene copolymer, and ethylene-octene copolymer; (2) The polyolefin elastomer has a Shore hardness of 40A~70A; (3) The compatibilizer is a PEO graft; Optionally, the compatibilizer includes one or more of maleic anhydride-grafted POE, amino-grafted POE, glycidyl methacrylate-grafted POE, hydroxyl-grafted POE, carboxylic acid-grafted POE, or imide-grafted POE. Optionally, the grafting rate of the compatibilizer is 0.3~3wt%; (4) The plasticizer includes one or more of propylene glycol dibenzoate, dipropylene glycol dibenzoate, ethylene glycol dibenzoate, diethylene glycol dibenzoate, diethylene glycol dibenzoate, neopentyl glycol dibenzoate, and pentylene glycol dibenzoate.

8. The low-hardness, high-strength alloy material according to claim 6 or 7, characterized in that, At least one of the following conditions must be met: (1) 50-85% thermoplastic polyurethane; (2) Polyolefin elastomer 10-20%; (3) Compatibilizer 5-8%; (4) Plasticizer 15-30%.

9. A method for preparing a low-hardness, high-strength alloy material according to any one of claims 6-8, characterized in that, Includes the following steps: After mixing the raw materials, the mixture is melt-extruded using a twin-screw extruder to obtain the low-hardness, high-strength alloy material. Optionally, the step of mixing the raw materials includes: first mixing the thermoplastic polyurethane with the plasticizer, and then mixing it with the polyolefin elastomer and compatibilizer; Optionally, the temperature of the melt extrusion is 100~180℃ and the screw speed is 200~450rpm.

10. The application of the low-hardness high-strength alloy material according to any one of claims 6-8 or the low-hardness high-strength alloy material prepared by the preparation method according to claim 9 in films, sheets, extruded pipes, and extruded cables.

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