TPU (thermoplastic polyurethane) nucleating agent as well as preparation method and application thereof

Abstract

The invention relates to the field of compositions for bionic TPU (thermoplastic polyurethane) additive materials, and particularly discloses a TPU nucleating agent as well as a preparation method and application thereof. Comprising the following raw materials in parts by mass: 30-50 parts of a modified inorganic alpha nucleating agent; 10 to 20 parts of benzamide cyclohexanecarboxylic acid; the modified inorganic alpha nucleating agent comprises an inorganic alpha nucleating agent modified by an N-(2-aminoethyl)-3-aminopropyl trimethoxy silane coupling agent and an inorganic alpha nucleating agent modified by a heptadecafluorodecyl trimethoxy silane coupling agent. The nucleating agent prepared in the invention is suitable for bionic TPU additive materials, and the prepared TPU elastomer has high tensile strength and elongation at break.

Description

Technical Field

[0001] This application relates to the field of compositions for bionic TPU, and more specifically, it relates to a TPU nucleating agent, its preparation method and applications. Background Art

[0002] A nucleating agent is a functional filler that promotes the crystallization of polymers and improves their crystal grain structure. By improving the crystallization of resins and other conditions, the properties of resins are enhanced. Existing nucleating agents are usually used for nucleation of plastics that are not fully crystalline, such as polypropylene and polyethylene.

[0003] TPU, namely thermoplastic polyurethane elastomer, is a type of (AB) n type block linear polymer. It is enhanced by 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, combining the characteristics of rubber and plastic, and also having excellent biocompatibility. It is one of the main series of recognized blood and biocompatible materials. Since the last century, people have begun to try to use TPU materials as flexible polymer medical pacemakers. However, due to in vivo degradation and environmental stress cracking, a large number of pacemaker leads have failed.

[0004] With the development of 3D printing technology, TPU has been applied to manufacture products such as organ models, prosthetics, and bionic skin through fused deposition additive manufacturing (FDM), selective laser sintering (SLS) 3D printing technology, etc. These fields have relatively high requirements for the strength, flexibility, hydrophobicity, and processability of materials. Some researchers have added reinforcing fillers to TPU. Although the mechanical strength of the material has been enhanced, the elongation at break of the prepared TPU material has decreased significantly, and it cannot meet the requirements for flexibility in applications such as artificial organs, bionic skin, and wound dressings. Some researchers have added a large amount of β nucleating agent to TPU, but the β nucleating agent is thermodynamically unstable and easily converts to the α crystal form. In order to simulate the human signal feedback mechanism to design bionic TPU additive prosthetic skin, etc., scientists have blended TPU with ionic liquids to obtain an ionic skin material, thereby sensing the magnitude of external pressure. In order to improve the sensing sensitivity of the TPU prosthetic ionic skin, scientists have introduced highly electronegative chlorine groups into the side chains of TPU. By attracting ionic liquids with chlorine groups, the initial capacitance is reduced, but the prepared material is prone to degradation in a humid and hot environment.

[0005] The properties of TPU are closely related to its crystallization situation. How to provide a nucleating agent that can be evenly distributed in TPU materials, improve the crystallization situation of TPU materials, and enable the prepared TPU materials to 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 bio-inspired TPU additives, the present application provides a TPU nucleating agent, its preparation method and application.

[0007] First of all, the present application provides a TPU nucleating agent; the nucleating agent comprises the following raw material components in parts by mass: 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 N-(2-aminoethyl)-3-aminopropyltrimethoxysilane coupling agent modified inorganic α nucleating agent and 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.

[0008] Benzamide cyclohexanecarboxylic acid is an amide β nucleating agent. When used together with the inorganic α nucleating agent, it enriches the crystal structure of the obtained TPU. At the same time, benzamide cyclohexanecarboxylic acid has high nucleation efficiency and thermodynamic stability. A better orientation arrangement can be achieved between the two side cyclic structures, the molecular chains aggregate better, the β crystal form crystallization rate is high, and the strength and flexibility of TPU are improved. The hyperbranched chain segment of benzoic acid hyperbranched polyester can provide more crystal nuclei and further optimize the grains of the obtained TPU.

[0009] Talc powder, mica, calcium carbonate, and silica have small sizes, wide sources, and good nucleation effects. After modifying the inorganic α-nucleating agent with N-(2-aminoethyl)-3-aminopropyltrimethoxysilane coupling agent, due to the presence of groups such as amino groups in N-(2-aminoethyl)-3-aminopropyltrimethoxysilane coupling agent, the modified fumed silica can achieve better compatibility and dispersion in TPU, and slightly crosslink with isocyanate groups to form acylurea, forming a network structure with certain strength and chain segment mobility, achieving a closer connection with TPU. At the same time, since N-(2-aminoethyl)-3-aminopropyltrimethoxysilane coupling agent has no many side chains, it does not increase much entropy while improving the crystallization performance of TPU, reducing the crystallization free energy, promoting the nucleation of TPU, and enhancing the crystallization performance. By modifying the inorganic α-nucleating agent with heptadecafluorodecyltrimethoxysilane coupling agent, the modified inorganic α-nucleating agent is attached with more F atoms with large electronegativity. The shared electrons strongly tend to the F atoms, generating an electrostatic attraction with the nearby H atoms, thus forming hydrogen bonds, with a higher degree of crystallization and good effect on strength improvement. At the same time, perhaps due to the certain steric hindrance of benzamide cyclohexanecarboxylic acid and benzoic acid hyperbranched polyester, they have a certain interpenetrating locking with the heptadecafluorodecyltrimethoxysilane coupling agent-modified inorganic α-nucleating agent with long chain segments. The interpenetrating part between the two plays a role similar to an elastic crosslinking point, and a certain degree of slippage can occur between the interpenetrating chain segments. The prepared TPU has better flexible performance after being stressed, is not easy to crack, and has more stable performance. Some long chain segments span between the soft segments and hard segments of TPU, overcoming the bondage of hydrogen bonds between the hard segments themselves and rearranging to form microcrystals. The combined action of the active chain segment interpenetration, hydrogen bonds, and hyperbranched microcrystalline nuclei promotes the relatively ordered arrangement of short-range molecules during the crystallization process of TPU, maintaining a certain degree of mobility in the long range, optimizing the crystallization performance of TPU, and the prepared TPU has both high strength and flexibility. The addition of the heptadecafluorodecyltrimethoxysilane coupling agent-modified inorganic α-nucleating agent can also make the bionic TPU additive more hydrophobic, and make the ionic liquid in the system attracted by the fluorodecyl group with higher electronegativity, not easy to move under an external electric field, thus reducing the initial capacitance and enhancing the sensitivity of the bionic additive. The active interpenetrating point between benzamide cyclohexanecarboxylic acid and benzoic acid hyperbranched polyester and the heptadecafluorodecyltrimethoxysilane coupling agent-modified inorganic α-nucleating agent also enables the ionic liquid to overflow better after the TPU additive is stressed, making the capacitance change sensitively, and is more suitable for use in bionic TPU additives.

[0010] 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).

[0011] The inventors found that when the mass ratio of the modified inorganic α-nucleating agent, benzamide cyclohexanecarboxylic acid, and benzoic acid hyperbranched polyester was (42 - 45):15:(2 - 4), the nucleating agent prepared had the best performance when used in TPU. It was speculated that at this time, more β-crystals were formed by benzamide cyclohexanecarboxylic acid, and more microcrystals were formed by benzoic acid hyperbranched polyester. The modified inorganic α-nucleating agent interspersed among them, and the "elastic crosslinking points" were evenly distributed while the number was not too large, so that the TPU prepared would not be too rigid due to excessive benzene rings, and all aspects of performance reached the optimum.

[0012] In a specific embodiment, the inorganic α-nucleating agent is fumed silica with a particle size of 5 - 25 nm.

[0013] Through the above preparation scheme, the inorganic α-nucleating agent can be well modified, and at the same time, it can be well dispersed in the system, not easily form large spherulites, and the crystallization is relatively uniform and stable, and the performance of the prepared TPU is more stable.

[0014] In a specific embodiment, the modified inorganic α-nucleating agent with 1,1,2,2,3,3,4,4,5,5,6,6,7,7,7 - heptadecafluorodecyltrimethoxysilane coupling agent and benzamide cyclohexanecarboxylic acid are premixed.

[0015] Through the above preparation scheme, it may be because the modified inorganic α-nucleating agent with 1,1,2,2,3,3,4,4,5,5,6,6,7,7,7 - heptadecafluorodecyltrimethoxysilane coupling agent has more F atoms with large electronegativity, and there is an electrostatic attraction between it and benzamide cyclohexanecarboxylic acid, so that the modified inorganic α-nucleating agent with 1,1,2,2,3,3,4,4,5,5,6,6,7,7,7 - heptadecafluorodecyltrimethoxysilane coupling agent forms a certain protection for 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 modified inorganic α-nucleating agent with 1,1,2,2,3,3,4,4,5,5,6,6,7,7,7 - heptadecafluorodecyltrimethoxysilane coupling agent with low surface energy partially coats benzamide cyclohexanecarboxylic acid, the cyclic structure of benzamide cyclohexanecarboxylic acid can achieve better orientation arrangement among TPU, and the β-crystal form crystallization rate is high, further improving the strength and flexibility of TPU.

[0016] In a specific embodiment, the mass ratio of the modified inorganic α-nucleating agent with 1,1,2,2,3,3,4,4,5,5,6,6,7,7,7 - heptadecafluorodecyltrimethoxysilane coupling agent and benzamide cyclohexanecarboxylic acid is (25 - 27):15.

[0017] Through the above preparation scheme, the modified inorganic α-nucleating agent with 1,1,2,2,3,3,4,4,5,5,6,6,7,7,7 - heptadecafluorodecyltrimethoxysilane coupling agent can have a good protection effect on benzamide cyclohexanecarboxylic acid, and at the same time, it will not completely shield benzamide cyclohexanecarboxylic acid due to excessive modified inorganic α-nucleating agent with 1,1,2,2,3,3,4,4,5,5,6,6,7,7,7 - heptadecafluorodecyltrimethoxysilane coupling agent to reduce the formation of β-crystals, nor will it cause the product to be too rigid due to excessive benzamide cyclohexanecarboxylic acid. After the prepared nucleating agent is used in TPU, it can produce a certain microphase separation effect when stressed, and the flexibility performance is good.

[0018] In a specific embodiment, the weight-average molecular weight of benzoic acid hyperbranched polyester is 1000 - 2500.

[0019] At this molecular weight, benzoic acid hyperbranched polyester can generate more microcrystalline nuclei while achieving good dispersion in the system. After being premixed with the inorganic α-nucleating agent modified by 1,1,2,2,3,3,4,4,5,5,6,6,7,7,7-heptadecafluorodecyltrimethoxysilane coupling agent, it can be well protected and achieve a certain degree of microphase separation, and the prepared TPU has good performance.

[0020] 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 for reaction, then adding dioxazoline, raising the temperature, and carrying out a reduced-pressure reaction to obtain benzoic acid hyperbranched polyester.

[0021] Conventional preparation processes can all be used to prepare the benzoic acid hyperbranched polyester of the present application. The present application preferably adopts the above preparation scheme. The preparation method is simple. The benzoic acid hyperbranched polyester has a large number of branching groups, can better control the molecular weight, and the number of phenyl groups and the steric hindrance formed are appropriate.

[0022] In a second aspect, the present application provides a preparation method of a TPU nucleating agent, including the following steps: weighing each component by mass, adding a solvent, mixing evenly, and spray-drying to obtain the nucleating agent. The inlet air temperature of the spray-drying is 150 - 170 °C, and the outlet air temperature is 80 - 90 °C.

[0023] Through the above preparation scheme, the preparation method is simple, suitable for preparing the nucleating agent components of the present application. The prepared nucleating agent components are uniform and have good nucleating effect.

[0024] In a third aspect, the present application provides an application of a TPU nucleating agent. The above nucleating agent is applied to medical TPU materials, and the mass ratio of TPU to the nucleating agent is (100 - 1000):1.

[0025] TPU has (AB) n type soft segments and hard segments. The hard segments are distributed in the soft segments to provide strength. It has both the high elasticity of rubber and the rigidity of plastic. The nucleating agent prepared in the present application is made by the mutual cooperation of long and short α and β nucleating agents. Through the settings of the surface groups, molecular weight, mass ratio, etc. of the nucleating agent, the chain segments span between the soft segments and hard segments of TPU. The short-range molecular order arranges for crystallization, and the long-range maintains a certain degree of mobility, adapting to the structural characteristics of TPU, improving 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 prosthetics, bionic blood vessels, bionic organs, etc.

[0026] In a specific embodiment, the R value of the TPU material is 1.0 - 1.2.

[0027] The R value refers to the ratio of the total equivalent number of isocyanate to hydroxyl groups of the prepolymer synthesized before dispersion. Through the above preparation scheme, the R value of the TPU material is limited, making it more suitable for using the nucleating agent of the present application. At this time, the ratio of the hard and soft segments of the TPU is suitable for the nucleating agent of the present application, with high nucleation efficiency, and the crystal nucleus distribution and crosslinking network are suitable for the TPU structure. The prepared TPU has both high strength and flexibility, with a high elongation at break, and is more suitable for use as bionic skin, bionic prosthetics, bionic blood vessels, bionic organs, etc.

[0028] In summary, the present application has at least the following beneficial effects: 1. The nucleating agent of the present application can, through the combined action of α and β nucleating agent components with different chain segment structures, form a network structure with a certain chain segment mobility inside the TPU, with a large number of benzamide cyclohexanecarboxylic acid and benzoic acid hyperbranched polyesters as nodes and a modified inorganic α nucleating agent with heptadecafluorodecyltrimethoxysilane coupling agent as the active chain segment. The formed "hard" nodes and "soft" active chain segments can achieve better coordination with the hard and soft block structures of the TPU, increasing the nucleation sites while optimizing the block network structure of the hard and soft segments. The prepared TPU has both high flexibility and strength. At the same time, the nucleating agent of the present application has more active amino groups and amide groups, and the active groups with different chain segment lengths slightly crosslink with the isocyanate groups of the TPU to form acylureas, optimizing the crosslinking structure of the TPU and being suitable for use with TPU. At the same time, a certain mass of fluorodecyl can improve the hydrophobicity of the TPU material and reduce the initial capacitance, and a certain number of active sites can improve the stress sensitivity of the ionic liquid, making it more suitable for bionic TPU additive manufacturing.

[0029] 2. By premixing the modified inorganic α nucleating agent with heptadecafluorodecyltrimethoxysilane coupling agent and benzamide cyclohexanecarboxylic acid and limiting their mass ratio, the present application enables the modified inorganic α nucleating agent with heptadecafluorodecyltrimethoxysilane coupling agent to provide a certain degree of protection for benzamide cyclohexanecarboxylic acid, increasing the proportion of β crystals to increase the flexibility of the TPU. At the same time, it blocks part of the lower surface energy, increasing the microphase separation from the TPU, and the TPU shows better elongation at break and strength under stress. Further limiting the mass ratio of the modified inorganic α nucleating agent with heptadecafluorodecyltrimethoxysilane coupling agent and benzamide cyclohexanecarboxylic acid and the weight average molecular weight of the benzoic acid hyperbranched polyester results in a better premixing effect.

[0030] 3. By limiting the application of the nucleating agent to TPU materials with a specific hard segment content and limiting their mass ratio, the prepared TPU has a reasonable structure and the best strength and flexibility performance, and has a relatively broad application prospect in high-end fields, especially in the preparation of ionic liquid bionic prosthetics by bionic TPU additive manufacturing. Specific Embodiments

[0031] To further assist in understanding the technical solution of the present invention, several specific embodiments are provided to describe the technical solution of the present invention more specifically. All these described embodiments are only partial embodiments of the present invention, not all of them; the embodiments can be combined with each other, and the same or similar concepts or processes may not be repeated in some embodiments. The following embodiments are further explanations of the present invention, and the present invention is not limited thereto.

[0032] Unless otherwise specified, the raw materials used in the embodiments and preparation examples of this application are all conventional commercially available brands or can be obtained according to conventional processes. The components of the preparation examples used in the embodiments refer to the components obtained by the way of the preparation examples.

[0033] The particle size of fumed silica is 20 nm, purchased from Xianfeng Nano XFI91; the particle size of silica micropowder is 50 nm, purchased from Xianfeng Nano XFF31.

[0034] Preparation Example

[0035] Preparation Example 1: Modification of fumed silica with N-(2-aminoethyl)-3-aminopropyltrimethoxysilane coupling agent Add 4 g of N-(2-aminoethyl)-3-aminopropyltrimethoxysilane coupling agent and 12 g of fumed silica into 100 ml of 50 vt% ethanol aqueous solution, stir, ultrasonic at 300 W for 5 minutes, stir and react at 75 °C for 2 hours, filter by suction, wash with deionized water 3 times, and dry to obtain N-(2-aminoethyl)-3-aminopropyltrimethoxysilane coupling agent-modified fumed silica.

[0036] Preparation Example 2: Modification of fumed silica with heptadecafluorodecyltrimethoxysilane coupling agent Add 4 g of heptadecafluorodecyltrimethoxysilane coupling agent and 12 g of fumed silica into 100 ml of 50 vt% ethanol aqueous solution, stir, ultrasonic at 300 W for 5 minutes, stir and react at 75 °C for 2 hours, filter by suction, wash with deionized water 3 times, and dry to obtain N-(2-aminoethyl)-3-aminopropyltrimethoxysilane coupling agent-modified fumed silica.

[0037] Preparation Example 3: Modification of silica micropowder with heptadecafluorodecyltrimethoxysilane coupling agent Add 4 g of heptadecafluorodecyltrimethoxysilane coupling agent and 12 g of silica micropowder into 100 ml of 50 vt% ethanol aqueous solution, stir, ultrasonic at 300 W for 5 minutes, stir and react at 75 °C for 2 hours, filter by suction, wash with deionized water 3 times, and dry to obtain heptadecafluorodecyltrimethoxysilane coupling agent-modified silica micropowder.

[0038] Preparation Example 4: Benzoic acid hyperbranched polyester 105 g of trimesic acid and 8.5 g of toluenesulfonic acid were added to 70 ml of ethylene glycol, stirred evenly, nitrogen was introduced, and the mixture was heated and reacted at 80 °C for 1 hour. Then 7 g of dioxazoline was added, the temperature was raised to 120 °C, and the reaction was carried out under vacuum for 1 hour. After drying, a hyperbranched polyester benzoate with a weight-average molecular weight of about 1100 was obtained.

[0039] Preparation Example 5: Hyperbranched Polyester Benzoate 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, nitrogen was introduced, and the mixture was heated and reacted 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 under vacuum for 0.5 hour. After drying, a hyperbranched polyester benzoate with a weight-average molecular weight of about 500 was obtained.

[0040] Preparation Example 6: 3-(2,3-Epoxypropoxy)propyltrimethoxysilane Coupling Agent Modified Fumed Silica 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 by suction, washed 3 times with deionized water, and dried to obtain 3-(2,3-epoxypropoxy)propyltrimethoxysilane coupling agent modified fumed silica.

[0041] Examples Example 1:

[0042] This example contains the following raw materials: 10 g of N-(2-aminoethyl)-3-aminopropyltrimethoxysilane coupling agent modified fumed silica prepared in Preparation Example 1, 40 g of heptadecafluorodecyltrimethoxysilane coupling agent modified fumed silica prepared in Preparation Example 2, 15 g of benzamide cyclohexanecarboxylic acid, and 3 g of hyperbranched polyester benzoate prepared in Preparation Example 4.

[0043] The preparation steps are as follows: Weigh each component by mass, mix them all and then stir evenly. Then add 40 ml of cyclohexane and 70 ml of ethanol, stir, ultrasonicate at 300 W for 10 minutes, and spray dry to obtain a nucleating agent. The inlet temperature of the spray drying is 160 °C, and the outlet temperature is 85 °C.

[0044] Example 2:

[0045] This example contains the following raw materials: 15 g of N-(2-aminoethyl)-3-aminopropyltrimethoxysilane coupling agent modified fumed silica prepared in Preparation Example 1, 15 g of heptadecafluorodecyltrimethoxysilane coupling agent modified fumed silica prepared in Preparation Example 2, 20 g of benzamide cyclohexanecarboxylic acid, and 5 g of hyperbranched polyester benzoate prepared in Preparation Example 4.

[0046] The preparation steps are as follows: Weigh each component by mass, mix them all and then stir evenly. Then add 40 ml of cyclohexane and 70 ml of ethanol, stir, perform ultrasonic treatment at 300 W for 10 minutes, and then spray dry to obtain the nucleating agent. The inlet air temperature for spray drying is 160 °C, and the outlet air temperature is 85 °C.

[0047] Example 3:

[0048] This example contains the following raw materials: 22 g of N-(2-aminoethyl)-3-aminopropyltrimethoxysilane-coupled agent-modified fumed silica prepared in Preparation Example 1, 22 g of heptadecafluorodecyltrimethoxysilane-coupled agent-modified fumed silica prepared in Preparation Example 2, 15 g of benzamide cyclohexanecarboxylic acid, and 3 g of benzoic acid hyperbranched polyester prepared in Preparation Example 4.

[0049] The preparation steps are as follows: Weigh each component by mass, mix them all and then stir evenly. Then add 40 ml of cyclohexane and 70 ml of ethanol, stir, perform ultrasonic treatment at 300 W for 10 minutes, and then spray dry to obtain the nucleating agent. The inlet air temperature for spray drying is 160 °C, and the outlet air temperature is 85 °C.

[0050] Example 4:

[0051] This example contains the following raw materials: 18 g of N-(2-aminoethyl)-3-aminopropyltrimethoxysilane-coupled agent-modified fumed silica prepared in Preparation Example 1, 26 g of heptadecafluorodecyltrimethoxysilane-coupled agent-modified fumed silica prepared in Preparation Example 2, 15 g of benzamide cyclohexanecarboxylic acid, and 3 g of benzoic acid hyperbranched polyester prepared in Preparation Example 4.

[0052] The preparation steps are as follows: Weigh each component by mass, mix them all and then stir evenly. Then add 40 ml of cyclohexane and 70 ml of ethanol, stir, perform ultrasonic treatment at 300 W for 10 minutes, and then spray dry to obtain the nucleating agent. The inlet air temperature for spray drying is 160 °C, and the outlet air temperature is 85 °C.

[0053] Example 5:

[0054] 22 g of N-(2-aminoethyl)-3-aminopropyltrimethoxysilane-coupled agent-modified fumed silica prepared in Preparation Example 1, 22 g of heptadecafluorodecyltrimethoxysilane-coupled agent-modified fumed silica prepared in Preparation Example 2, 15 g of benzamide cyclohexanecarboxylic acid, and 1 g of benzoic acid hyperbranched polyester prepared in Preparation Example 4.

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

[0056] Example 6:

[0057] 22 g of 3-(2,3-epoxypropoxy)propyltrimethoxysilane-coupled fumed silica prepared in Preparation Example 6, 22 g of heptadecafluorodecyltrimethoxysilane-coupled fumed silica prepared in Preparation Example 2, 15 g of benzamide cyclohexanecarboxylic acid, and 1 g of benzoic acid hyperbranched polyester prepared in Preparation Example 4.

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

[0059] Example 7:

[0060] This example contains the following raw materials: 22 g of N-(2-aminoethyl)-3-aminopropyltrimethoxysilane-coupled fumed silica prepared in Preparation Example 1, 22 g of heptadecafluorodecyltrimethoxysilane-coupled fumed silica prepared in Preparation Example 2, 15 g of benzamide cyclohexanecarboxylic acid, and 3 g of benzoic acid hyperbranched polyester prepared in Preparation Example 5.

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

[0062] Example 8:

[0063] This example contains the following raw materials: 22 g of N-(2-aminoethyl)-3-aminopropyltrimethoxysilane-coupled fumed silica prepared in Preparation Example 1, 22 g of heptadecafluorodecyltrimethoxysilane-coupled silica fine powder prepared in Preparation Example 3, 15 g of benzamide cyclohexanecarboxylic acid, and 3 g of benzoic acid hyperbranched polyester prepared in Preparation Example 4.

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

[0065] Example 9:

[0066] This example contains the following raw materials: 18 g of N-(2-aminoethyl)-3-aminopropyltrimethoxysilane-coupled fumed silica prepared in Preparation Example 1, 26 g of heptadecafluorodecyltrimethoxysilane-coupled fumed silica prepared in Preparation Example 2, 15 g of benzamide cyclohexanecarboxylic acid, and 3 g of benzoic acid hyperbranched polyester prepared in Preparation Example 4.

[0067] The preparation steps are as follows: Weigh each component by mass and set aside. First, premix the heptadecafluorodecyltrimethoxysilane-coupled fumed silica and benzamide cyclohexanecarboxylic acid, stir at 400 r / min for 5 minutes, then add the remaining raw materials, and then add a mixture of 40 ml of cyclohexane and 70 ml of ethanol, stir, ultrasonicate at 300 W for 10 minutes, and spray dry to obtain a nucleating agent. The inlet temperature of the spray drying is 160 °C, and the outlet temperature is 85 °C.

[0068] Example 10: This example contains the following raw materials: 18 g of N-(2-aminoethyl)-3-aminopropyltrimethoxysilane-coupled fumed silica prepared in Preparation Example 1, 26 g of heptadecafluorodecyltrimethoxysilane-coupled fumed silica prepared in Preparation Example 2, 12 g of benzamide cyclohexanecarboxylic acid, and 3 g of benzoic acid hyperbranched polyester prepared in Preparation Example 4.

[0069] The preparation steps are as follows: Weigh each component by mass and set aside. First, premix the heptadecafluorodecyltrimethoxysilane-coupled fumed silica and benzamide cyclohexanecarboxylic acid, stir at 400 r / min for 5 minutes, then add the remaining raw materials, and then add a mixture of 40 ml of cyclohexane and 70 ml of ethanol, stir, ultrasonicate at 300 W for 10 minutes, and spray dry to obtain a nucleating agent. The inlet temperature of the spray drying is 160 °C, and the outlet temperature is 85 °C.

[0070] Example 11: This example contains the following raw materials: 18 g of N-(2-aminoethyl)-3-aminopropyltrimethoxysilane-coupled fumed silica prepared in Preparation Example 1, 26 g of heptadecafluorodecyltrimethoxysilane-coupled fumed silica prepared in Preparation Example 2, 18 g of benzamide cyclohexanecarboxylic acid, and 3 g of benzoic acid hyperbranched polyester prepared in Preparation Example 4.

[0071] The preparation steps are as follows: Weigh each component by mass and set aside. First, premix the heptadecafluorodecyltrimethoxysilane-coupled fumed silica and benzamide cyclohexanecarboxylic acid, stir at 400 r / min for 5 minutes, then add the remaining raw materials, and then add a mixture of 40 ml of cyclohexane and 70 ml of ethanol, stir, ultrasonicate at 300 W for 10 minutes, and spray dry to obtain a nucleating agent. The inlet temperature of the spray drying is 160 °C, and the outlet temperature is 85 °C.

[0072] Comparative Example

[0073] Comparative Example 1 This comparative example contains the following raw materials: 44 g of N-(2-aminoethyl)-3-aminopropyltrimethoxysilane-coupled fumed silica prepared in Preparation Example 1, 15 g of benzamide cyclohexanecarboxylic acid, and 3 g of benzoic acid hyperbranched polyester prepared in Preparation Example 4.

[0074] The preparation steps are as follows: Weigh each component by mass, mix them all and then stir evenly. Then add 40 ml of cyclohexane and 70 ml of ethanol, stir, perform ultrasonic treatment at 300 W for 10 minutes, and spray dry to obtain a nucleating agent. The inlet temperature of the spray drying is 160 °C and the outlet temperature is 85 °C.

[0075] Comparative Example 2 This comparative example contains the following raw materials: 44 g of heptadecafluorodecyltrimethoxysilane-coupled fumed silica prepared in Preparation Example 2, 15 g of benzamide cyclohexanecarboxylic acid, and 3 g of benzoic acid hyperbranched polyester prepared in Preparation Example 4.

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

[0077] Comparative Example 3 This comparative example contains the following raw materials: 22 g of N-(2-aminoethyl)-3-aminopropyltrimethoxysilane-coupled fumed silica prepared in Preparation Example 1, 37 g of heptadecafluorodecyltrimethoxysilane-coupled fumed silica prepared in Preparation Example 2, and 3 g of benzoic acid hyperbranched polyester prepared in Preparation Example 4.

[0078] The preparation steps are as follows: Weigh each component by mass, mix them all and then stir evenly. Then add 40 ml of cyclohexane and 70 ml of ethanol, stir, perform ultrasonic treatment at 300 W for 10 minutes, and spray dry to obtain a nucleating agent. The inlet temperature of the spray drying is 160 °C and the outlet temperature is 85 °C.

[0079] Comparative Example 4 This comparative example contains the following raw materials: 22 g of N-(2-aminoethyl)-3-aminopropyltrimethoxysilane-coupled fumed silica prepared in Preparation Example 1, 37 g of benzamide cyclohexanecarboxylic acid, and 3 g of benzoic acid hyperbranched polyester prepared in Preparation Example 4.

[0080] The preparation steps are as follows: Weigh each component by mass, mix them all and then stir evenly. Then add 40 ml of cyclohexane and 70 ml of ethanol, stir, and perform ultrasonic treatment at 300 W for 10 minutes. After that, conduct spray drying to obtain the nucleating agent. The inlet air temperature for spray drying is 160 °C, and the outlet air temperature is 85 °C.

[0081] Performance testing methods

[0082] Add 2 g of the nucleating agents prepared in the examples and comparative examples respectively to 1000 g of TPU with an R value of 1.2. After mixing and stirring evenly in a high-speed mixer, conduct mixing, extrusion, and granulation through a twin-screw extruder, and press into a 2-mm sheet using a flat vulcanizing machine. The extrusion temperature is 190 °C, and the rotation speed of the twin-screw reactive extruder is 380 r / min. TPU with different R values is all purchased from Anda Huatai (the soft segment is PTMEG, the hard segment is HMDI, and the chain extender is DMPA). Then conduct performance testing, and the test results are shown in Table 1; Add 2 g of the nucleating agents prepared in Example 3 and Comparative Examples 1-4 respectively to 1000 g of TPU with an R value of 1.3. After mixing and stirring evenly in a high-speed mixer, conduct mixing, extrusion, and granulation through a twin-screw extruder, and press into a 2-mm sheet using a flat vulcanizing machine. The extrusion temperature is 190 °C, and the rotation speed of the twin-screw reactive extruder is 380 r / min. TPU with different R values is all purchased from Anda Huatai (the soft segment is PTMEG, the hard segment is HMDI, and the chain extender is DMPA). Then conduct performance testing, and the test results are shown in Table 2; Add 2 g of the nucleating agents prepared in Example 3 and Comparative Examples 1-4 to 1000 g of block copolymer polypropylene J641. After mixing and stirring evenly in a high-speed mixer, conduct mixing, extrusion, and granulation through a twin-screw extruder, and press into a 2-mm sheet using a flat vulcanizing machine. The extrusion temperature is 280 °C, and the rotation speed of the twin-screw reactive extruder is 380 r / min. Then conduct performance testing, and the test results are shown in Table 3; Performance testing: Test 1: Refer to the standard "GB / T 528-2009 Tensile Stress-Strain Performance" to test the tensile strength of the sample at an ambient temperature of 25 °C and a relative humidity (RH) of 50%.

[0083] Test 2: Refer to the standard "ASTM D624" to test the elongation at break of the sample. The instrument model is AZS-X of Shimadzu Corporation at an ambient temperature of 25 °C and a relative humidity (RH) of 50%.

[0084] Table 1 Tensile strength / (MPa) Elongation at break / % Example 1 13.01 232 Example 2 13.22 223 Example 3 13.63 229 Example 4 14.39 257 Example 5 13.42 227 Example 6 13.16 204 Example 7 13.30 222 Example 8 13.32 224 Example 9 14.67 281 Example 10 13.99 246 Example 11 14.04 240 Comparative Example 1 9.13 121 Comparative Example 2 7.43 142 Comparative Example 3 9.22 124 Comparative Example 4 9.31 117 Combined with Examples 1-3, Comparative Examples 1-4 and Table 1, when the components of the present application are in a certain mass and act together through α and β nucleating agent components with different chain segment structures, a network structure with certain chain segment mobility can be formed inside the TPU, with a large number of benzamide cyclohexanecarboxylic acid and benzoic acid hyperbranched polyesters as nodes and the modified inorganic α nucleating agent with heptadecafluorodecyltrimethoxysilane coupling agent as the active chain segment. The prepared TPU has both high strength and elongation at break.

[0085] Combined with Examples 3-6 and Table 1, by limiting the mass ratio of the modified inorganic α nucleating agent, benzamide cyclohexanecarboxylic acid and benzoic acid hyperbranched polyester, the active network structure involved in the cross-linking of TPU and formed is more reasonable, further improving the strength and elongation at break of TPU.

[0086] Combined with Examples 3 and 7 and Table 1, by limiting the weight average molecular weight of benzoic acid hyperbranched polyester, the performance of TPU is further improved.

[0087] Combined with Examples 3 and 8 and Table 1, by limiting the parameters of fumed silica, the prepared TPU has better performance.

[0088] Combined with Examples 4 and 9 and Table 1, by premixing the modified inorganic α nucleating agent with heptadecafluorodecyltrimethoxysilane coupling agent and benzamide cyclohexanecarboxylic acid, the β crystal content and the degree of microphase separation are increased, and the elongation at break is further improved.

[0089] Combined with Examples 4 and 10-11 and Table 1, by limiting the mass ratio of the modified inorganic α nucleating agent with heptadecafluorodecyltrimethoxysilane coupling agent and benzamide cyclohexanecarboxylic acid, the β crystal content and microphase separation are increased, and the elongation at break is further improved.

[0090] Table 2 Tensile strength / (MPa) Elongation at break / % Example 3 8.77 167 Comparative Example 1 7.74 147 Comparative Example 2 7.32 151 Comparative Example 3 6.39 141 Comparative Example 4 6.42 137 Table 3 Tensile strength / (MPa) Elongation at break / % Example 3 28.7 427 Comparative Example 1 27.8 401 Comparative Example 2 25.4 411 Comparative Example 3 26.2 423 Comparative Example 4 26.4 416 Combined with Examples 3, Comparative Examples 1-4 and Tables 2-3, the degree of enhancing the strength and elongation at break performance in TPU with an R value of 1.3 and block copolymerized polypropylene is not as significant as that in TPU with an R value of 1.2.

[0091] This specific embodiment is only an explanation of the present application and does not limit the present application. Those skilled in the art can make modifications without creative contributions to this embodiment according to needs after reading this specification, but as long as it is within the scope of the claims of the present application, it is protected by the patent law.

Claims

1. A TPU nucleating agent, characterized in that, Comprising the following raw material components in parts by mass: 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 inorganic α - nucleating agent modified by N-(2 - aminoethyl)-3 - aminopropyltrimethoxysilane coupling agent and an inorganic α - nucleating agent modified by heptadecafluorodecyltrimethoxysilane coupling agent, and the inorganic α - nucleating agent includes one or more of talc powder, mica, calcium carbonate, and silica.

2. The TPU nucleating agent according to claim 1, wherein 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 inorganic α - nucleating agent is fumed silica with a particle size of 5 - 25 nm.

4. The TPU nucleating agent according to claim 1, wherein The inorganic α - nucleating agent modified by heptadecafluorodecyltrimethoxysilane coupling agent and benzamide cyclohexanecarboxylic acid are premixed.

5. The TPU nucleating agent according to claim 4, characterized in that, The mass ratio of the inorganic α - nucleating agent modified by heptadecafluorodecyltrimethoxysilane coupling agent and benzamide cyclohexanecarboxylic acid is (25 - 27):

15.

6. The TPU nucleating agent according to claim 4, wherein The weight - average molecular weight of the benzoic acid hyperbranched polyester is 1000 - 2500.

7. The TPU nucleating agent according to claim 1, wherein The preparation steps of the benzoic acid hyperbranched polyester include: adding trimellitic acid and toluenesulfonic acid into ethylene glycol, stirring evenly, introducing nitrogen, heating for reaction, then adding dioxazoline, raising the temperature, and carrying out a reduced - pressure reaction to obtain the benzoic acid hyperbranched polyester.

8. A preparation method of the TPU nucleating agent according to any one of claims 1-7, characterized in that, Including the following steps: weighing each component by mass, adding a solvent, mixing evenly, 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.

9. Use of a TPU nucleating agent as described in any one of claims 1-7, characterized in that: Applied as a nucleating agent to TPU material, the mass ratio of TPU to the nucleating agent is (100 - 1000):

1.

10. The application of the TPU nucleating agent according to claim 9, characterized in that, The R value of the TPU material is 1.0 - 1.2.