A TPU nucleating agent and its preparation method and application

Abstract

The present application relates to the field of biomimetic TPU additive compositions, specifically disclosing a TPU nucleating agent, its preparation method, and application. The invention comprises the following raw materials in parts by weight: 30-50 parts of a modified inorganic α-nucleating agent; 10-20 parts of benzamide cyclohexanecarboxylic acid; and 1-5 parts of a benzoic acid hyperbranched polyester. The modified inorganic α-nucleating agent includes an inorganic α-nucleating agent modified with an N-(2-aminoethyl)-3-aminopropyltrimethoxysilane coupling agent and an inorganic α-nucleating agent modified with a heptadecafluorodecyltrimethoxysilane coupling agent. The nucleating agent prepared in the present application is suitable for biomimetic TPU additives, and the resulting TPU elastomer has both high tensile strength and elongation at break.

Description

Technical Field

[0001] The present application relates to the field of biomimetic TPU compositions, and more specifically, to a TPU nucleating agent, a preparation method thereof, and an application thereof. Background Art

[0002] A nucleating agent is a functional filler that promotes polymer crystallization and improves its grain structure. It improves the performance of the resin by improving the crystallization of the resin. Existing nucleating agents are usually used for nucleation of incompletely crystallized plastics such as polypropylene and polyethylene.

[0003] TPU is a thermoplastic TPU flexible body, which is a (AB) n TPU is a segmented linear polymer that relies on intermolecular hydrogen bonds and slight chemical cross-linking between macromolecular chains. The hard segments are distributed in the soft segments to form a discontinuous microphase structure reinforcement. It has the characteristics of both rubber and plastic and has excellent biocompatibility. It is recognized as one of the main series of blood and biocompatible materials. Since the last century, people have begun to try to use TPU materials as flexible polymer medical pacemakers, but due to degradation in the body and cracking due to environmental stress, a large number of pacemaker wires have failed.

[0004] With the advancement of 3D printing technology, TPU has been applied to the manufacture of organ models, prosthetics, and bionic skins through fused deposition modeling (FDM) and laser sintering (SLS) 3D printing techniques. These applications place high demands on the material's strength, flexibility, hydrophobicity, and ease of processing. Some researchers have added reinforcing fillers to TPU. While this has enhanced the material's mechanical strength, the resulting TPU material's elongation at break has significantly decreased, failing to meet the flexibility requirements for applications such as artificial organs, bionic skins, and wound dressings. Some researchers have added large amounts of β-nucleating agents to TPU, but β-nucleating agents are thermodynamically unstable and tend to transform into α-crystalline forms. To mimic the human body's signal feedback mechanisms and design biomimetic TPU additive prosthetic skins, scientists have blended TPU with ionic liquids to create an ionic skin material that can sense external pressure. To improve the sensitivity of the TPU prosthetic ionic skin, scientists have introduced highly electronegative chlorine groups onto the side chains of the TPU. These chlorine groups attract the ionic liquid, reducing the initial capacitance. However, the resulting material is susceptible to degradation in hot and humid environments.

[0005] The performance of TPU is closely related to its crystallization. How to provide a nucleating agent that can be evenly distributed in the TPU material, improve the crystallization of the TPU material, and make the obtained TPU material stably have high tensile strength and elongation at break is of great significance for expanding the application fields of TPU materials, especially bionic TPU additives and the selection of medical materials. Summary of the Invention

[0006] In order to enable the nucleating agent to better improve the crystallization of TPU materials, especially biomimetic TPU additives, the present application provides a TPU nucleating agent and its preparation method and application.

[0007] First, the present application provides a TPU nucleating agent; the nucleating agent comprises the following raw material components in parts by weight:

[0008] 30-50 parts of modified inorganic α-nucleating agent;

[0009] 10-20 parts of benzamide cyclohexanecarboxylic acid;

[0010] 1-5 parts of benzoic acid hyperbranched polyester;

[0011] The modified inorganic α-nucleating agent includes an N-(2-aminoethyl)-3-aminopropyltrimethoxysilane coupling agent modified inorganic α-nucleating agent and a heptadecafluorodecyltrimethoxysilane coupling agent modified inorganic α-nucleating agent, and the inorganic α-nucleating agent includes one or more of talc, mica, calcium carbonate, and silica.

[0012] Benzamide-cyclohexanecarboxylic acid is an amide-type β-nucleating agent. When used in conjunction with an inorganic α-nucleating agent, it enriches the crystal structure of the resulting TPU. Benzamide-cyclohexanecarboxylic acid also exhibits high nucleation efficiency and thermodynamic stability. This allows for better orientation between the ring structures on either side, resulting in better molecular chain aggregation and a high β-crystallinity rate, enhancing the strength and flexibility of the TPU. The hyperbranched segments of benzoic acid-based hyperbranched polyesters provide more crystal nuclei, further optimizing the resulting TPU grains.

[0013] Talc, mica, calcium carbonate, and silica are relatively small in size, widely available, and have a good nucleation effect. After the inorganic α-nucleating agent is modified with N-(2-aminoethyl)-3-aminopropyltrimethoxysilane coupling agent, the presence of amino groups and other groups in the N-(2-aminoethyl)-3-aminopropyltrimethoxysilane coupling agent enables the modified fumed silica to achieve better compatibility and dispersion in TPU, and slightly cross-links with the isocyanate group to form urea, forming a network structure with certain strength and chain segment activity, achieving a closer connection with the TPU. At the same time, since the N-(2-aminoethyl)-3-aminopropyltrimethoxysilane coupling agent does not have many side chains, it improves the crystallization performance of TPU without increasing much entropy, reduces the crystallization free energy, promotes TPU nucleation, and improves the crystallization performance. By modifying the inorganic α-nucleating agent with a heptadecafluorodecyltrimethoxysilane coupling agent, the modified inorganic α-nucleating agent is attached with a larger number of highly electronegative F atoms. The shared electrons are strongly biased toward the F atoms, generating electrostatic attraction with nearby H atoms, thus forming hydrogen bonds, resulting in a higher degree of crystallinity and a better strength-enhancing effect. Furthermore, perhaps due to the steric hindrance of the benzamide cyclohexanecarboxylic acid and benzoic acid hyperbranched polyester, a certain degree of interpenetration and interlocking occurs with the long-chain segments of the heptadecafluorodecyltrimethoxysilane coupling agent-modified inorganic α-nucleating agent. The interpenetrating portions of the two act like elastic crosslinks, allowing a certain degree of slip between the interpenetrating segments. The resulting TPU exhibits greater flexibility and toughness under stress, is less prone to cracking, and has more stable performance. Some long chain segments span between the soft and hard segments of the TPU, overcoming the constraints of hydrogen bonds between the hard segments themselves and rearranging to form microcrystals. The interpenetration of active segments, hydrogen bonds, and hyperbranched micronuclei work together to promote a more ordered arrangement of molecules in the short range during TPU crystallization, while maintaining a certain degree of mobility in the long range. This optimizes the crystallization performance of TPU, resulting in a TPU with both high strength and flexibility. The addition of an inorganic α-nucleating agent modified with heptadecafluorodecyltrimethoxysilane coupling agent also makes the biomimetic TPU additive more hydrophobic and attracts the ionic liquid within the system to the more electronegative fluorodecyl groups, making it less likely to move when an external electric field is applied, thereby reducing the initial capacitance and improving the sensitivity of the biomimetic additive. The active interpenetration points of benzamide cyclohexanecarboxylic acid and benzoic acid hyperbranched polyester with the inorganic α-nucleating agent modified with heptadecafluorodecyltrimethoxysilane coupling agent also enable the ionic liquid to overflow better when the TPU additive is subjected to force, resulting in sensitive changes in capacitance, making it more suitable for use in biomimetic TPU additives.

[0014] In a specific embodiment, the mass ratio of the modified inorganic α-nucleating agent, benzamide cyclohexanecarboxylic acid and benzoic acid hyperbranched polyester is (42-45):15:(2-4).

[0015] The inventors found that when the mass ratio of the modified inorganic α-nucleating agent, benzamide cyclohexanecarboxylic acid, and benzoic acid hyperbranched polyester is limited to (42-45):15:(2-4), the performance of the obtained nucleating agent after being used in TPU is the best. It is speculated that at this time, benzamide cyclohexanecarboxylic acid forms more β crystals and benzoic acid hyperbranched polyester forms more microcrystals. The modified inorganic α-nucleating agent is interspersed between the two, and the "elastic cross-linking points" are evenly distributed and the number is not too large. The TPU obtained will not be too rigid due to too many benzene rings, and the performance in all aspects is optimized.

[0016] In a specific embodiment, the inorganic alpha nucleating agent is fumed silica with a particle size of 5-25 nm.

[0017] Through the above preparation scheme, the inorganic α-nucleating agent can achieve better modification and better dispersion in the system, is not easy to form large spherulites, and has more uniform and stable crystallization, so that the performance of the prepared TPU is more stable.

[0018] In a specific embodiment, the inorganic α-nucleating agent modified with heptadecafluorodecyltrimethoxysilane coupling agent and benzamide cyclohexanecarboxylic acid are premixed.

[0019] Through the above preparation scheme, it may be because the inorganic α-nucleating agent modified by the heptadecafluorodecyltrimethoxysilane coupling agent has more F atoms with greater electronegativity, which produces electrostatic attraction between the inorganic α-nucleating agent modified by the heptadecafluorodecyltrimethoxysilane coupling agent and the benzamide cyclohexanecarboxylic acid, so that the inorganic α-nucleating agent modified by the heptadecafluorodecyltrimethoxysilane coupling agent provides certain protection for the benzamide cyclohexanecarboxylic acid. After the prepared nucleating agent is added to TPU, β-crystals can be better formed, and the product is more flexible and elastic. At the same time, after the inorganic α-nucleating agent modified by the heptadecafluorodecyltrimethoxysilane coupling agent with low surface energy partially coats the benzamide cyclohexanecarboxylic acid, the ring structure of the benzamide cyclohexanecarboxylic acid can achieve better directional arrangement between the TPU, and the β-crystal crystallization rate is high, which further improves the strength and flexibility of the TPU.

[0020] In a specific embodiment, the mass ratio of the heptadecafluorodecyltrimethoxysilane coupling agent modified inorganic α-nucleating agent to the benzamide cyclohexanecarboxylic acid is (25-27):15.

[0021] Through the above preparation scheme, the inorganic α-nucleating agent modified by heptadecafluorodecyltrimethoxysilane coupling agent can have a good protective effect on benzamide cyclohexanecarboxylic acid. At the same time, the excessive amount of inorganic α-nucleating agent modified by heptadecafluorodecyltrimethoxysilane coupling agent will not completely shield the benzamide cyclohexanecarboxylic acid and reduce the formation of β crystals, nor will the excessive amount of benzamide cyclohexanecarboxylic acid cause the product to be too rigid. After the prepared nucleating agent is used in TPU, it can produce a certain microphase separation effect when subjected to stress, and has good flexibility.

[0022] In a specific embodiment, the weight average molecular weight of the benzoic acid hyperbranched polyester is 1000-2500.

[0023] At this molecular weight, benzoic acid hyperbranched polyester can generate more microcrystalline nuclei while achieving better dispersion in the system. After premixing with the inorganic α-nucleating agent modified by heptadecafluorodecyltrimethoxysilane coupling agent, it can be well protected and achieve a certain degree of microphase separation, and the resulting TPU has good performance.

[0024] In a specific embodiment, the preparation steps of benzoic acid hyperbranched polyester include: adding trimesic acid and toluenesulfonic acid to ethylene glycol, stirring evenly, introducing nitrogen, heating to react, then adding dioxazoline, heating, and reducing pressure to react to obtain benzoic acid hyperbranched polyester.

[0025] Conventional preparation processes can be used to prepare the benzoic acid hyperbranched polyester of the present application. The present application prefers the above preparation scheme, which is simple in preparation method. The benzoic acid hyperbranched polyester has a large number of branched groups, which can better control the molecular weight, and the number of phenyl groups and the size of the steric hindrance formed are appropriate.

[0026] In a second aspect, the present application provides a method for preparing a TPU nucleating agent, comprising the following steps: weighing each component by mass, adding a solvent, mixing evenly, and spray drying to obtain a nucleating agent, wherein the inlet air temperature of the spray drying is 150-170°C, and the outlet air temperature is 80-90°C.

[0027] Through the above preparation scheme, the preparation method is simple and suitable for the preparation of the nucleating agent component of the present application. The prepared nucleating agent component is uniform and has a good nucleating effect.

[0028] In a third aspect, the present application provides an application of a TPU nucleating agent, wherein the nucleating agent is applied to medical TPU materials, and the mass ratio of TPU to nucleating agent is (100-1000):1.

[0029] TPU due to (AB) n The TPU has a soft segment and a hard segment block, and the hard segment is distributed in the soft segment to provide strength. It has both the high elasticity of rubber and the rigidity of plastic. The nucleating agent prepared in this application cooperates with each other through the long and short α and β nucleating agents. The chain segments span between the soft and hard segments of TPU through the setting of the surface groups, molecular weight, mass ratio, etc. of the nucleating agent. The short-range molecules are arranged and crystallized in an orderly manner, and the long-range maintains a certain activity, which adapts to the structural characteristics of TPU and improves the crystallization performance of TPU. The prepared TPU has both high strength and elongation at break, and is more suitable for use as bionic skin, bionic prosthesis, bionic blood vessels, bionic organs, etc.

[0030] In a specific embodiment, the TPU material has an R value of 1.0-1.2.

[0031] The R value refers to the total equivalent ratio of isocyanate to hydroxyl groups in the prepolymer synthesized before dispersion. Through the above preparation scheme, the R value of the TPU material is limited, which is more suitable for the use of the nucleating agent of this application. At this time, the ratio of soft and hard segments of TPU is suitable for the nucleating agent of this application, the nucleation efficiency is high, the crystal nucleus distribution and the cross-linking network are suitable for the TPU structure, and the prepared TPU has both high strength and flexibility, and high elongation at break, and is more suitable for use as bionic skin, bionic prostheses, bionic blood vessels, bionic organs, etc.

[0032] In summary, this application has at least the following beneficial effects:

[0033] The nucleating agent of the present application, through the combined action of α and β nucleating agent components with different segment structures, can form a network structure with certain segment activity inside TPU, with a large amount of benzamide cyclohexanecarboxylic acid and benzoic acid hyperbranched polyester as nodes and inorganic α nucleating agent modified by heptadecafluorodecyltrimethoxysilane coupling agent as active segments. The formed "hard" nodes and "soft" active segments can achieve good coordination with the soft and hard block structure of TPU, increasing the nucleation sites while optimizing the block network structure of the soft and hard segments. The resulting TPU has both high flexibility and strength. At the same time, the nucleating agent of the present application has a large number of active amino and amide groups. The active groups on different segment lengths slightly cross-link with the isocyanate groups of TPU to form urea, optimizing the cross-linking structure of TPU and making it suitable for TPU use. At the same time, a certain amount of fluorodecyl groups can improve the hydrophobicity and reduce the initial capacitance of the TPU material, and certain active sites can improve the force sensitivity of ionic liquids, making it more suitable for use in bionic TPU additives.

[0034] 2. This application premixes a heptadecafluorodecyltrimethoxysilane coupling agent-modified inorganic α-nucleating agent with benzamide-cyclohexanecarboxylic acid and defines a specific mass ratio. This allows the heptadecafluorodecyltrimethoxysilane coupling agent-modified inorganic α-nucleating agent to provide a certain degree of protection for the benzamide-cyclohexanecarboxylic acid, increasing the β-crystal ratio and thus enhancing the flexibility of the TPU. Furthermore, the surface energy of the obscured portion is lowered, increasing microphase separation from the TPU, and resulting in improved elongation at break and strength performance of the TPU under stress. Further defining the mass ratio of the heptadecafluorodecyltrimethoxysilane coupling agent-modified inorganic α-nucleating agent to the benzamide-cyclohexanecarboxylic acid, as well as the weight-average molecular weight of the benzoic acid hyperbranched polyester, results in even better premixing results.

[0035] 3. This application limits the application of nucleating agents to TPU materials with specific hard segment content and limits the mass ratio of the two. The resulting TPU has a reasonable structure and optimal strength and flexibility. It has broad application prospects in high-end fields, especially in ionic liquid bionic prostheses prepared by bionic TPU additives. DETAILED DESCRIPTION

[0036] To further facilitate understanding of the technical solution of the present invention, several specific embodiments are provided to provide a more detailed description of the technical solution of the present invention. These embodiments are only partial embodiments of the present invention, not all of them. The embodiments may be combined with each other, and the same or similar concepts or processes may not be described in detail in some embodiments. The following embodiments further illustrate the present invention, but the present invention is not limited thereto.

[0037] Unless otherwise specified, the raw materials used in the examples and preparation examples of this application are all conventional commercial brands, or can be prepared according to conventional processes. The components of the preparation examples used in the examples are all components obtained by the preparation examples.

[0038] The particle size of the fumed silica was 20 nm and was purchased from Xianfeng Nano XFI91; the particle size of the silica micropowder was 50 nm and was purchased from Xianfeng Nano XFF31.

[0039] Preparation Example

[0040] Preparation Example 1: N-(2-aminoethyl)-3-aminopropyltrimethoxysilane coupling agent modified fumed silica

[0041] 4 g of N-(2-aminoethyl)-3-aminopropyltrimethoxysilane coupling agent and 12 g of fumed silica were added to 100 ml of 50% ethanol aqueous solution, stirred, ultrasonicated at 300 W for 5 minutes, stirred and reacted at 75 ° C for 2 hours, filtered, washed with deionized water 3 times, and dried to obtain N-(2-aminoethyl)-3-aminopropyltrimethoxysilane coupling agent modified fumed silica.

[0042] Preparation Example 2: Heptafluorodecyltrimethoxysilane coupling agent modified fumed silica

[0043] 4 g of heptadecafluorodecyltrimethoxysilane coupling agent and 12 g of fumed silica were added to 100 ml of 50 wt% ethanol aqueous solution, stirred, ultrasonicated at 300 W for 5 minutes, stirred and reacted at 75 ° C for 2 hours, filtered, washed with deionized water 3 times, and dried to obtain heptadecafluorodecyltrimethoxysilane coupling agent modified fumed silica.

[0044] Preparation Example 3: Heptafluorodecyltrimethoxysilane coupling agent modified silica powder

[0045] 4 g of heptadecafluorodecyltrimethoxysilane coupling agent and 12 g of silica powder were added to 100 ml of 50 wt% ethanol aqueous solution, stirred, ultrasonicated at 300 W for 5 minutes, stirred at 75 ° C for 2 hours, filtered, washed with deionized water 3 times, and dried to obtain heptadecafluorodecyltrimethoxysilane coupling agent modified silica powder.

[0046] Preparation Example 4: Benzoic acid hyperbranched polyester

[0047] 105 g of trimesic acid and 8.5 g of toluenesulfonic acid were added to 70 ml of ethylene glycol, stirred evenly, introduced with nitrogen, and heated at 80° C. for 1 hour. Then, 7 g of dioxazoline was added, the temperature was raised to 120° C., vacuum reacted for 1 hour, and dried to obtain a benzoic acid hyperbranched polyester with a weight-average molecular weight of approximately 1100.

[0048] Preparation Example 5: Benzoic acid hyperbranched polyester

[0049] 55 g of trimesic acid, 4.5 g of toluenesulfonic acid and 3 g of benzoic acid were added to 70 ml of ethylene glycol, stirred evenly, introduced with nitrogen, and heated at 80° C. for 1 hour. Then, 4 g of dioxazoline was added, the temperature was raised to 110° C., and the reaction was carried out in vacuum for 0.5 hour. The mixture was dried to obtain a benzoic acid hyperbranched polyester with a weight-average molecular weight of about 500.

[0050] Preparation Example 6: 3-(2,3-epoxypropoxy)propyltrimethoxysilane coupling agent modified fumed silica

[0051] 4 g of 3-(2,3-epoxypropoxy)propyltrimethoxysilane coupling agent and 12 g of fumed silica were added to 100 ml of 50 vt% ethanol aqueous solution, stirred, ultrasonicated at 300 W for 5 minutes, stirred and reacted at 75 ° C for 2 hours, filtered, washed with deionized water 3 times, and dried to obtain 3-(2,3-epoxypropoxy)propyltrimethoxysilane coupling agent modified fumed silica.

[0052] Example

[0053] Example 1:

[0054] This example contains the following raw materials: 10 g of N-(2-aminoethyl)-3-aminopropyltrimethoxysilane coupling agent modified fumed silica obtained in Preparation Example 1, 40 g of heptadecafluorodecyltrimethoxysilane coupling agent modified fumed silica obtained in Preparation Example 2, 15 g of benzamide cyclohexanecarboxylic acid, and 3 g of benzoic acid hyperbranched polyester obtained in Preparation Example 4.

[0055] The preparation steps are as follows: weigh each component by mass, mix all and stir evenly, then add 40 ml of cyclohexane and 70 ml of ethanol, stir, ultrasonicate at 300W for 10 minutes, spray dry to obtain a nucleating agent, and the inlet air temperature of the spray drying is 160°C and the outlet air temperature is 85°C.

[0056] Example 2:

[0057] This example contains the following raw materials: 15 g of N-(2-aminoethyl)-3-aminopropyltrimethoxysilane coupling agent modified fumed silica obtained in Preparation Example 1, 15 g of heptadecafluorodecyltrimethoxysilane coupling agent modified fumed silica obtained in Preparation Example 2, 20 g of benzamide cyclohexanecarboxylic acid, and 5 g of benzoic acid hyperbranched polyester obtained in Preparation Example 4.

[0058] The preparation steps are as follows: weigh each component by mass, mix all and stir evenly, then add 40 ml of cyclohexane and 70 ml of ethanol, stir, ultrasonicate at 300W for 10 minutes, spray dry to obtain a nucleating agent, and the inlet air temperature of the spray drying is 160°C and the outlet air temperature is 85°C.

[0059] Example 3:

[0060] This example contains the following raw materials: 22 g of N-(2-aminoethyl)-3-aminopropyltrimethoxysilane coupling agent modified fumed silica obtained in Preparation Example 1, 22 g of heptadecafluorodecyltrimethoxysilane coupling agent modified fumed silica obtained in Preparation Example 2, 15 g of benzamide cyclohexanecarboxylic acid, and 3 g of benzoic acid hyperbranched polyester obtained in Preparation Example 4.

[0061] The preparation steps are as follows: weigh each component by mass, mix all and stir evenly, then add 40 ml of cyclohexane and 70 ml of ethanol, stir, ultrasonicate at 300W for 10 minutes, spray dry to obtain a nucleating agent, and the inlet air temperature of the spray drying is 160°C and the outlet air temperature is 85°C.

[0062] Example 4:

[0063] This example contains the following raw materials: 18 g of N-(2-aminoethyl)-3-aminopropyltrimethoxysilane coupling agent modified fumed silica obtained in Preparation Example 1, 26 g of heptadecafluorodecyltrimethoxysilane coupling agent modified fumed silica obtained in Preparation Example 2, 15 g of benzamide cyclohexanecarboxylic acid, and 3 g of benzoic acid hyperbranched polyester obtained in Preparation Example 4.

[0064] The preparation steps are as follows: weigh each component by mass, mix all and stir evenly, then add 40 ml of cyclohexane and 70 ml of ethanol, stir, ultrasonicate at 300W for 10 minutes, spray dry to obtain a nucleating agent, and the inlet air temperature of the spray drying is 160°C and the outlet air temperature is 85°C.

[0065] Example 5:

[0066] 22 g of N-(2-aminoethyl)-3-aminopropyltrimethoxysilane coupling agent modified fumed silica obtained in Preparation Example 1, 22 g of heptadecafluorodecyltrimethoxysilane coupling agent modified fumed silica obtained in Preparation Example 2, 15 g of benzamide cyclohexanecarboxylic acid, and 1 g of benzoic acid hyperbranched polyester obtained in Preparation Example 4.

[0067] The preparation steps are as follows: weigh each component by mass, mix all and stir evenly, then add 40 ml of cyclohexane and 70 ml of ethanol, stir, ultrasonicate at 300W for 10 minutes, spray dry to obtain a nucleating agent, and the inlet air temperature of the spray drying is 160°C and the outlet air temperature is 85°C.

[0068] Example 6:

[0069] 22 g of fumed silica modified with 3-(2,3-epoxypropoxy)propyltrimethoxysilane coupling agent obtained in Preparation Example 6, 22 g of fumed silica modified with heptadecafluorodecyltrimethoxysilane coupling agent obtained in Preparation Example 2, 15 g of benzamide cyclohexanecarboxylic acid, and 1 g of benzoic acid hyperbranched polyester obtained in Preparation Example 4.

[0070] The preparation steps are as follows: weigh each component by mass, mix all and stir evenly, then add 40 ml of cyclohexane and 70 ml of ethanol, stir, ultrasonicate at 300W for 10 minutes, spray dry to obtain a nucleating agent, and the inlet air temperature of the spray drying is 160°C and the outlet air temperature is 85°C.

[0071] Example 7:

[0072] This example contains the following raw materials: 22 g of N-(2-aminoethyl)-3-aminopropyltrimethoxysilane coupling agent modified fumed silica obtained in Preparation Example 1, 22 g of heptadecafluorodecyltrimethoxysilane coupling agent modified fumed silica obtained in Preparation Example 2, 15 g of benzamide cyclohexanecarboxylic acid, and 3 g of benzoic acid hyperbranched polyester obtained in Preparation Example 5.

[0073] The preparation steps are as follows: weigh each component by mass, mix all and stir evenly, then add 40 ml of cyclohexane and 70 ml of ethanol, stir, ultrasonicate at 300W for 10 minutes, spray dry to obtain a nucleating agent, and the inlet air temperature of the spray drying is 160°C and the outlet air temperature is 85°C.

[0074] Example 8:

[0075] This example contains the following raw materials: 22 g of N-(2-aminoethyl)-3-aminopropyltrimethoxysilane coupling agent modified fumed silica obtained in Preparation Example 1, 22 g of silica powder modified with heptadecafluorodecyltrimethoxysilane coupling agent obtained in Preparation Example 3, 15 g of benzamide cyclohexanecarboxylic acid, and 3 g of benzoic acid hyperbranched polyester obtained in Preparation Example 4.

[0076] The preparation steps are as follows: weigh each component by mass, mix all and stir evenly, then add 40 ml of cyclohexane and 70 ml of ethanol, stir, ultrasonicate at 300W for 10 minutes, spray dry to obtain a nucleating agent, and the inlet air temperature of the spray drying is 160°C and the outlet air temperature is 85°C.

[0077] Example 9:

[0078] This example contains the following raw materials: 18 g of N-(2-aminoethyl)-3-aminopropyltrimethoxysilane coupling agent modified fumed silica obtained in Preparation Example 1, 26 g of heptadecafluorodecyltrimethoxysilane coupling agent modified fumed silica obtained in Preparation Example 2, 15 g of benzamide cyclohexanecarboxylic acid, and 3 g of benzoic acid hyperbranched polyester obtained in Preparation Example 4.

[0079] The preparation steps are as follows: each component is weighed by mass and set aside. First, the fumed silica modified with heptadecafluorodecyltrimethoxysilane coupling agent and benzamide cyclohexanecarboxylic acid are premixed and stirred at 400 r / min for 5 minutes. Then, the remaining raw materials are added, and then a mixture of 40 ml of cyclohexane and 70 ml of ethanol is added. The mixture is stirred, ultrasonicated at 300 W for 10 minutes, and spray-dried to obtain a nucleating agent. The inlet air temperature of the spray drying is 160°C and the outlet air temperature is 85°C.

[0080] Example 10:

[0081] This example contains the following raw materials: 18 g of N-(2-aminoethyl)-3-aminopropyltrimethoxysilane coupling agent modified fumed silica obtained in Preparation Example 1, 26 g of heptadecafluorodecyltrimethoxysilane coupling agent modified fumed silica obtained in Preparation Example 2, 12 g of benzamide cyclohexanecarboxylic acid, and 3 g of benzoic acid hyperbranched polyester obtained in Preparation Example 4.

[0082] The preparation steps are as follows: each component is weighed by mass and set aside. First, the fumed silica modified with heptadecafluorodecyltrimethoxysilane coupling agent and benzamide cyclohexanecarboxylic acid are premixed and stirred at 400 r / min for 5 minutes. Then, the remaining raw materials are added, and then a mixture of 40 ml of cyclohexane and 70 ml of ethanol is added. The mixture is stirred, ultrasonicated at 300 W for 10 minutes, and spray-dried to obtain a nucleating agent. The inlet air temperature of the spray drying is 160°C and the outlet air temperature is 85°C.

[0083] Example 11:

[0084] This example contains the following raw materials: 18 g of N-(2-aminoethyl)-3-aminopropyltrimethoxysilane coupling agent modified fumed silica obtained in Preparation Example 1, 26 g of heptadecafluorodecyltrimethoxysilane coupling agent modified fumed silica obtained in Preparation Example 2, 18 g of benzamide cyclohexanecarboxylic acid, and 3 g of benzoic acid hyperbranched polyester obtained in Preparation Example 4.

[0085] The preparation steps are as follows: each component is weighed by mass and set aside. First, the fumed silica modified with heptadecafluorodecyltrimethoxysilane coupling agent and benzamide cyclohexanecarboxylic acid are premixed and stirred at 400 r / min for 5 minutes. Then, the remaining raw materials are added, and then a mixture of 40 ml of cyclohexane and 70 ml of ethanol is added. The mixture is stirred, ultrasonicated at 300 W for 10 minutes, and spray-dried to obtain a nucleating agent. The inlet air temperature of the spray drying is 160°C and the outlet air temperature is 85°C.

[0086] Comparative Example

[0087] Comparative Example 1

[0088] This comparative example contains the following raw materials: 44 g of N-(2-aminoethyl)-3-aminopropyltrimethoxysilane coupling agent modified fumed silica obtained in Preparation Example 1, 15 g of benzamide cyclohexanecarboxylic acid, and 3 g of benzoic acid hyperbranched polyester obtained in Preparation Example 4.

[0089] The preparation steps are as follows: weigh each component by mass, mix all and stir evenly, then add 40 ml of cyclohexane and 70 ml of ethanol, stir, ultrasonicate at 300W for 10 minutes, spray dry to obtain a nucleating agent, and the inlet air temperature of the spray drying is 160°C and the outlet air temperature is 85°C.

[0090] Comparative Example 2

[0091] This comparative example contains the following raw materials: 44 g of fumed silica modified with heptadecafluorodecyltrimethoxysilane coupling agent obtained in Preparation Example 2, 15 g of benzamide cyclohexanecarboxylic acid, and 3 g of benzoic acid hyperbranched polyester obtained in Preparation Example 4.

[0092] The preparation steps are as follows: weigh each component by mass, mix all and stir evenly, then add 40 ml of cyclohexane and 70 ml of ethanol, stir, ultrasonicate at 300W for 10 minutes, spray dry to obtain a nucleating agent, and the inlet air temperature of the spray drying is 160°C and the outlet air temperature is 85°C.

[0093] Comparative Example 3

[0094] This comparative example contains the following raw materials: 22 g of N-(2-aminoethyl)-3-aminopropyltrimethoxysilane coupling agent modified fumed silica obtained in Preparation Example 1, 37 g of heptadecafluorodecyltrimethoxysilane coupling agent modified fumed silica obtained in Preparation Example 2, and 3 g of benzoic acid hyperbranched polyester obtained in Preparation Example 4.

[0095] The preparation steps are as follows: weigh each component by mass, mix all and stir evenly, then add 40 ml of cyclohexane and 70 ml of ethanol, stir, ultrasonicate at 300W for 10 minutes, spray dry to obtain a nucleating agent, and the inlet air temperature of the spray drying is 160°C and the outlet air temperature is 85°C.

[0096] Comparative Example 4

[0097] This comparative example contains the following raw materials: 22 g of N-(2-aminoethyl)-3-aminopropyltrimethoxysilane coupling agent modified fumed silica obtained in Preparation Example 1, 37 g of benzamide cyclohexanecarboxylic acid, and 3 g of benzoic acid hyperbranched polyester obtained in Preparation Example 4.

[0098] The preparation steps are as follows: weigh each component by mass, mix all and stir evenly, then add 40 ml of cyclohexane and 70 ml of ethanol, stir, ultrasonicate at 300W for 10 minutes, spray dry to obtain a nucleating agent, and the inlet air temperature of the spray drying is 160°C and the outlet air temperature is 85°C.

[0099] Performance testing methods

[0100] 2 g of the nucleating agent prepared in the examples and comparative examples was respectively added to 1000 g of TPU with an R value of 1.2. After being mixed and stirred uniformly in a high-speed mixer, the mixture was extruded and granulated by a twin-screw extruder, and then pressed into 2 mm sheets using a flat vulcanizer. The extrusion temperature was 190° C. and the speed of the twin-screw reaction extruder was 380 r / min. TPU with different R values were purchased from Anda Huatai (PTMEG as the soft segment, HMDI as the hard segment, and DMPA as the chain extender). Performance tests were then carried out. The test results are shown in Table 1.

[0101] 2 g of the nucleating agent prepared in Example 3 and Comparative Examples 1-4 was added to 1000 g of TPU with an R value of 1.3, mixed and stirred in a high-speed mixer, and then extruded into granules using a twin-screw extruder. The granules were then pressed into 2 mm sheets using a flat vulcanizer. The extrusion temperature was 190° C. and the speed of the twin-screw extruder was 380 r / min. TPUs with different R values were all purchased from Anda Huatai (PTMEG as the soft segment, HMDI as the hard segment, and DMPA as the chain extender). Performance tests were then carried out. The test results are shown in Table 2.

[0102] 2 g of the nucleating agent prepared in Example 3 and Comparative Examples 1-4 was added to 1000 g of block copolymer polypropylene J641, mixed and stirred uniformly in a high-speed mixer, and then extruded and granulated using a twin-screw extruder. The extrusion temperature was 280° C., and the speed of the twin-screw reaction extruder was 380 r / min. Performance tests were then conducted. The test results are shown in Table 3.

[0103] Performance testing:

[0104] Test 1: The tensile strength of the sample was tested according to the standard "GB / T 528-2009 Tensile Stress-Strain Properties" at an ambient temperature of 25°C and a relative humidity (RH) of 50%.

[0105] Test 2: The elongation at break of the sample was tested according to ASTM D624. The instrument model was AZS-X from Shimadzu Instrument Co., Ltd. The ambient temperature was 25°C and the relative humidity (RH) was 50%.

[0106] Table 1

[0107]

[0108] In combination with Examples 1-3, Comparative Examples 1-4 and Table 1, the components of the present application act together at a certain mass through α and β nucleating agent components with different segment structures. A network structure with certain segment activity can be formed inside the TPU, with a large amount of benzamide cyclohexanecarboxylic acid and benzoic acid hyperbranched polyester as nodes and an inorganic α nucleating agent modified with a heptadecafluorodecyltrimethoxysilane coupling agent as an active segment. The resulting TPU has both high strength and elongation at break.

[0109] In combination with Examples 3-6 and Table 1, the present application limits the mass ratio of the modified inorganic α-nucleating agent, benzamide cyclohexanecarboxylic acid and benzoic acid hyperbranched polyester, so that the active network structure involved in the crosslinking of TPU and the formation is more reasonable, thereby further improving the strength and elongation at break of TPU.

[0110] In combination with Examples 3 and 7 and Table 1, the present application further improves the performance of TPU by limiting the weight average molecular weight of benzoic acid hyperbranched polyester.

[0111] In combination with Examples 3 and 8 and Table 1, the TPU prepared in this application has better performance by limiting the parameters of fumed silica.

[0112] In combination with Examples 4 and 9 and Table 1, the present application premixes the inorganic α-nucleating agent modified with heptadecafluorodecyltrimethoxysilane coupling agent and benzamide cyclohexanecarboxylic acid to increase the β-crystal content and the degree of microphase separation, thereby further improving the elongation at break.

[0113] In combination with Examples 4, 10-11 and Table 1, the present application increases the β crystal content and microphase separation by limiting the mass ratio of the inorganic α nucleating agent modified by the heptadecafluorodecyltrimethoxysilane coupling agent and the benzamide cyclohexanecarboxylic acid, thereby further improving the elongation at break.

[0114] Table 2

[0115]

[0116] Table 3

[0117]

[0118] In combination with Example 3, Comparative Examples 1-4 and Tables 2-3, the degree of enhancement of the strength and elongation at break properties in TPU and block copolymer polypropylene with an R value of 1.3 in the present application is not as significant as in TPU with an R value of 1.2.

[0119] This specific embodiment is merely an explanation of the present application and is not a limitation of the present application. After reading this specification, those skilled in the art may make non-creative modifications to the present embodiment as needed, but as long as they are within the scope of the claims of the present application, they are protected by the patent law.

Claims

1. A TPU nucleating agent, characterized in that The raw material components include the following parts by weight: 30-50 parts of modified inorganic α-nucleating agent; 10-20 parts of benzamide cyclohexanecarboxylic acid; 1-5 parts of benzoic acid hyperbranched polyester; The modified inorganic α nucleating agent includes an N-(2-aminoethyl)-3-aminopropyltrimethoxysilane coupling agent modified inorganic α nucleating agent and a heptadecafluorodecyltrimethoxysilane coupling agent modified inorganic α nucleating agent; The inorganic α nucleating agent is fumed silica with a particle size of 5 to 25 nm; The weight average molecular weight of the benzoic acid hyperbranched polyester is 1000-2500; The heptadecafluorodecyltrimethoxysilane coupling agent modified inorganic α nucleating agent and benzamide cyclohexanecarboxylic acid are premixed; The preparation steps of the benzoic acid hyperbranched polyester include: adding trimesic acid and toluenesulfonic acid to ethylene glycol, stirring evenly, introducing nitrogen, heating for reaction, then adding dioxazoline, heating, and reducing pressure to obtain the benzoic acid hyperbranched polyester.

2. The TPU nucleating agent according to claim 1, characterized in that The mass ratio of the modified inorganic α-nucleating agent, benzamide cyclohexanecarboxylic acid and benzoic acid hyperbranched polyester is (42-45):15:(2-4).

3. The TPU nucleating agent according to claim 1, characterized in that The mass ratio of the heptadecafluorodecyltrimethoxysilane coupling agent modified inorganic α-nucleating agent and benzamide cyclohexanecarboxylic acid is (25-27):

15.

4. A method for preparing a TPU nucleating agent according to any one of claims 1 to 3, characterized in that: The method comprises the following steps: weighing each component by mass, adding a solvent, mixing uniformly, and spray drying to obtain a nucleating agent. The inlet air temperature of the spray drying is 150-170°C, and the outlet air temperature is 80-90°C.

5. A use of the TPU nucleating agent according to any one of claims 1 to 3, characterized in that: Applied to TPU materials as nucleating agent, the mass ratio of TPU to nucleating agent is (100-1000):

1.

6. The use of the TPU nucleating agent according to claim 5, characterized in that: The R value of the TPU material is 1.0-1.2.

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