A high-strength, high-elasticity ionic conductive thermoplastic elastomer and its preparation method

Abstract

The present invention relates to the technical field of thermoplastic elastomers, and discloses a high-strength and high-elasticity ionic conductive thermoplastic elastomer and a preparation method thereof. The ionic conductive thermoplastic elastomer comprises a hard segment unit having a structure shown in Formula I and a soft segment unit having a structure shown in Formula II; R1 is selected from one or more of a substituted ureido group, a carbamate group, and a substituted or unsubstituted aryl group; R2 is selected from one or more of an aliphatic alkylene group, an aromatic hydrocarbon group, and an ether group; R3 is a group containing positive and negative ion pairs. The thermoplastic elastomer provided by the present invention has the characteristics of high strength, high elasticity, and high conductivity, which is beneficial to applications in the flexible electronics industry. Moreover, the preparation method in the embodiments of the present invention is simple and easy to implement.

Description

Technical Field

[0001] The present invention relates to the technical field of thermoplastic elastomers, and particularly to a high-strength, high-elasticity ionic conductive thermoplastic elastomer and a preparation method thereof. Background Art

[0002] As a special type of polymer material, thermoplastic elastomers have a wide range of applications in industrial production and daily life. The molecular structure of thermoplastic elastomers usually consists of soft segments and hard segments. The flexible soft segment structure endows them with excellent deformation ability and toughness, while the rigid hard segments provide a relatively large modulus and strength. Generally speaking, by adjusting structural factors such as the molecular structure and composition ratio of the soft segment and / or hard segment, various thermoplastic elastomer materials with rich and variable mechanical properties can be obtained. However, due to the coexistence of soft segment and hard segment molecular structures in thermoplastic elastomers, their strength and modulus are always lower than those of some glassy polymers. On the other hand, the absence of chemical crosslinking in thermoplastic elastomers enables them to be easily subjected to repetitive thermal processing and solution processing, but also causes obvious permanent deformation when large deformations occur, and compared with chemically crosslinked rubbers, they exhibit lower elastic recovery ability.

[0003] More importantly, in recent years, with the continuous development of the flexible electronics industry, the demand for high-strength, high-elasticity, and conductive elastomers has been increasing. Commonly used conductive polymers mainly include: intrinsic electronic conductive polymers, ionic thermoplastic conductive polymers, etc. However, at present, intrinsic electronic conductive polymers are significantly brittle and not suitable for large deformation application scenarios; ionic thermoplastic conductive polymers usually require the additional addition of freely movable ionic compounds, which severely reduces their strength and elastic recovery ability; there are also some chemically crosslinked ionic conductive polymers, although they have relatively good strength and elastic recovery ability, their deformation amount is usually small and they cannot be repeatedly processed. Recently, it has also been reported that ionic compounds are fixed to the hard segment structure of thermoplastic elastomers, obtaining certain strength, elasticity, and affinity for ionic liquids, but their isolated ionic units cannot form a conductive path, so they exhibit obvious insulating characteristics (Adv. Funct. Mater. 2022, 32, 2106341).

[0004] Therefore, there is an urgent need to develop a thermoplastic elastomer with high strength, high elastic recovery ability, and good conductive ability to meet the development needs of the increasingly prosperous flexible electronics industry. Summary of the Invention

[0005] In view of this, the present invention provides a high-strength, high-elasticity ionic conductive thermoplastic elastomer and a preparation method thereof. The thermoplastic elastomer provided by this application has characteristics such as high strength, high elastic recovery ability, and high conductivity, which are beneficial for applications in the flexible electronics industry.

[0006] The present invention provides an ionic conductive thermoplastic elastomer with high strength and high resilience, which comprises hard segment units having the structure shown in Formula I and soft segment units having the structure shown in Formula II;

[0007]

[0008] Among them, R1 is selected from one or more of a substituted ureido group, a carbamate ester group, and a substituted or unsubstituted aryl group; R2 is selected from one or more of an aliphatic alkylene group, an aromatic hydrocarbon group, and an ether group; R3 is a group containing positive and negative ion pairs.

[0009] Preferably, R3 is a group containing an imidazole ion pair, a pyridine ion pair, a quaternary ammonium salt, or a quaternary phosphonium salt.

[0010] Preferably, R1 is selected from one or more of an aliphatic chain biureido group, a dicarbamate ester group, a phenyl group, a naphthyl group, and an anthracenyl group; R2 is selected from a symmetric ether group.

[0011] The present invention provides a method for preparing the ionic conductive thermoplastic elastomer as described above, comprising the following steps:

[0012] Polymerize the hard segment monomer shown in Formula 1, the first soft segment monomer shown in Formula 2, and the second soft segment monomer shown in Formula 3 to obtain the ionic conductive thermoplastic elastomer;

[0013]

[0014] Among them, R1 is selected from one or more of a substituted ureido group, a carbamate ester group, and a substituted or unsubstituted aryl group; R2 is selected from one or more of an aliphatic alkylene group, an aromatic hydrocarbon group, and an ether group; R3 is a group containing positive and negative ion pairs.

[0015] Preferably, the method for preparing the ionic conductive thermoplastic elastomer is specifically as follows:

[0016] Dissolve the hard segment monomer shown in Formula 1, the first soft segment monomer shown in Formula 2, and the second soft segment monomer shown in Formula 3 in a solvent, and carry out a polymerization reaction under ultraviolet light with a wavelength of 365 nm for a certain period of time to obtain the ionic conductive thermoplastic elastomer.

[0017] Preferably, the molar ratio of the hard segment monomer, the first soft segment monomer, and the second soft segment monomer is (1 to 10):(2 to 21):(1 to 10).

[0018] Preferably, the solvent is a volatile organic solvent, which can be one or more of dichloromethane, chloroform, tetrahydrofuran, and acetone.

[0019] Preferably, the polymerization reaction is carried out under the condition of adding a catalyst.

[0020] Preferably, the catalyst is benzoin dimethyl ether, and the addition amount does not exceed 1 wt% of the total mass of the reactants.

[0021] Preferably, the temperature of the polymerization reaction is the natural temperature, the reaction time is 2 - 2000 min; the reaction pressure is preferably 1 atmospheric pressure.

[0022] Compared with the prior art, the present application provides a thermoplastic elastomer with high strength, high resilience, and high conductivity, which comprises hard segment units with the structure shown in Formula I and soft segment units with the structure shown in Formula II; wherein, R1 is selected from one or more of a substituted urea group, a carbamate group, and a substituted or unsubstituted aryl group; R2 is selected from one or more of an aliphatic alkylene group, an aromatic hydrocarbon group, and an ether group; R3 is a group containing positive and negative ion pairs. The present invention mainly endows the elastomer with excellent strength and modulus through the hydrogen bonds or π-π interactions formed in the hard segment, or the synergistic effect of hydrogen bonds and π-π interactions, and at the same time utilizes the thermodynamic incompatibility characteristics between the two structures in the soft segment to endow the elastomer with excellent resilience; moreover, based on the excellent ionic conductivity in the soft segment units, the elastomer is endowed with good conductivity. In the preparation process of the examples of the present invention, by changing the chemical structure and component ratio of each segment unit, the performance of the elastomer can be effectively controlled.

[0023] Furthermore, the present invention can carry out the polymerization reaction by light irradiation, making the preparation of the thermoplastic elastomer simple. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 is a schematic structural diagram of the thermoplastic elastomer provided by the embodiment of the present invention;

[0025] Figure 2 is the 1H-NMR spectrum of the hard segment monomer in Example 1 of the present invention;

[0026] Figure 3 is the 1H-NMR spectrum of soft segment monomer 1 in Example 1 of the present invention;

[0027] Figure 4 is the 1H-NMR spectrum of soft segment monomer 2 in Example 1 of the present invention;

[0028] Figure 5 is the structural characterization diagram of the thermoplastic elastomer product in Example 1 of the present invention;

[0029] Figure 6 is the uniaxial tensile stress-strain curve of the thermoplastic elastomer prepared in Example 1 of the present invention;

[0030] Figure 7 is the conductivity test diagram of the thermoplastic elastomer prepared in Example 1 of the present invention;

[0031] Figure 8 is the uniaxial tensile stress-strain curve of the thermoplastic elastomer prepared in Example 2 of the present invention;

[0032] Figure 9 is the resilience test chart of the thermoplastic elastomer prepared in Example 2 of the present invention;

[0033] Figure 10 is the 1H-NMR spectrum of the hard segment monomer in Example 3 of the present invention;

[0034] Figure 11 is the structural characterization diagram of the thermoplastic elastomer product in Example 3 of the present invention;

[0035] Figure 12 is the cyclic compression stress-strain curve of the thermoplastic elastomer prepared in Example 3 of the present invention;

[0036] Figure 13 is the curve of the conductivity of the thermoplastic elastomer prepared in Example 4 of the present invention varying with strain;

[0037] Figure 14 is the NMR diagram of the elastomer product obtained in Comparative Example 1;

[0038] Figure 15 is the mechanical property diagram of the elastomer product obtained in Comparative Example 1;

[0039] Figure 16 is the structural characterization diagram of the product obtained in Comparative Example 2. Detailed implementation manners

[0040] The technical solutions in the embodiments of the present application will be described clearly and completely below. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments in the present application without creative efforts shall fall within the protection scope of the present application.

[0041] The present invention provides a high-strength, high-resilience ionic conductive thermoplastic elastomer, which comprises hard segment units with the structure shown in Formula I and soft segment units with the structure shown in Formula II; wherein, R1 is selected from one or more of a substituted urea group, a urethane group, and a substituted or unsubstituted aryl group; R2 is selected from one or more of an aliphatic alkylene group, an aromatic hydrocarbon group, and an ether group; R3 is a group containing positive and negative ion pairs;

[0042]

[0043] The thermoplastic elastomer provided by the present application has the characteristics of high strength, high resilience, and high conductivity, which is beneficial to the application in the flexible electronics industry.

[0044] See Figure 1 , which vividly shows the molecular chain structure of the thermoplastic elastomer described in the embodiments of the present invention; Figure 1 The elliptical region in represents the hard segment unit, which has the following structural characteristics:

[0045]

[0046] In the structure shown in Formula I, the group R1 connecting the carbonyl group can be selected from one or more of a substituted ureido group, a urethane group, and a substituted or unsubstituted aryl group, preferably one or more of an aliphatic chain biurea group, a dicarbamate group, a phenyl group, a naphthyl group, and an anthracenyl group. Exemplarily, the whole of Formula I is a hard segment unit containing an aliphatic chain biurea group represented by the following formula, and can also be a hard segment unit containing a urethane group or a benzene ring;

[0047]

[0048] And, Figure 1 The curve in represents the soft segment unit, and the specific structure is as shown in Formula II:

[0049]

[0050] The soft segment of Formula II contains structural features such as sulfur bonds and ion pairs. Among them, R2 connects two sulfur bonds and can be selected from one or more of an aliphatic alkylene group, an aromatic hydrocarbon group, and an ether group, preferably a symmetric ether group. R3 is a group containing positive and negative ion pairs, and further is a group containing an imidazole ion pair, a pyridine ion pair, a quaternary ammonium salt, or a quaternary phosphonium salt.

[0051] In view of the problem that the thermoplastic elastomer in the prior art exhibits insulation and is prone to permanent plastic deformation and poor resilience when subjected to large deformations, the present application provides the above-mentioned high-strength, high-resilience, ion-conductive thermoplastic elastomer. In the present invention, excellent strength and modulus are imparted to the elastomer mainly through the hydrogen bonds or π-π interactions formed in the hard segment, and / or the synergistic effect of hydrogen bonds and π-π interactions. At the same time, the high resilience of the elastomer is imparted by using the thermodynamic incompatibility characteristics between the two structures of the soft segment; based on the excellent ion conductivity in the soft segment unit, good conductivity is imparted to the elastomer, and through the synergistic coupling effect between the multiphases, effective regulation of the comprehensive performance of the thermoplastic elastomer is achieved.

[0052] In a specific embodiment of the present invention, the molar ratio of the soft segment to the hard segment of the ionic conductive thermoplastic elastomer is 1:1. The soft segment includes two parts, soft segment 1 and soft segment 2. By regulating soft segment 1 and soft segment 2, the macroscopic properties of the elastomer can be regulated, including mechanical properties, resilience, and electrical conductivity (the electrical conductivity can be illustrated by experiments such as lighting a bulb and strain sensing). The ionic conductive thermoplastic elastomers described in some embodiments are non-crystalline, and the polymer molecular weight is at a normal level. In some embodiments, the modulus of the ionic conductive thermoplastic elastomer material is within 10 MPa.

[0053] The present invention also provides a preparation method of the ionic conductive thermoplastic elastomer as described above, including the following steps: polymerizing the hard segment monomer shown in Formula 1, the first soft segment monomer shown in Formula 2, and the second soft segment monomer shown in Formula 3 to obtain the ionic conductive thermoplastic elastomer;

[0054]

[0055] wherein, R1 is selected from one or more of a substituted ureido group, a carbamate group, and a substituted or unsubstituted aryl group; R2 is selected from one or more of an aliphatic alkylene group, an aromatic hydrocarbon group, and an ether group; R3 is a group containing positive and negative ion pairs.

[0056] Specifically, the preparation method of the high-strength and high-resilience ionic conductive thermoplastic elastomer in the embodiments of the present application preferably includes:

[0057] Dissolving the corresponding hard segment monomer, the first soft segment monomer (which can be denoted as soft segment monomer 1), and the second soft segment monomer (soft segment monomer 2) in an appropriate solvent, and a certain catalyst can be added, and irradiated with ultraviolet light at a wavelength of 65 nm for a certain period of time to carry out a polymerization reaction. After the irradiation ends, the corresponding high-strength, high-resilience, and ionically conductive thermoplastic elastomer can be obtained.

[0058] In the embodiment of the present invention, the hard segment monomer has the following structural characteristics:

[0059]

[0060] wherein, R1 preferably represents one or more of an aliphatic chain bi-ureido group, a bi-carbamate group, a phenyl group, a naphthyl group, and an anthracenyl group. In some embodiments of the present invention, the hard segment monomer shown in Formula 1 is specifically as follows, which is an organic monomer containing an aliphatic chain bi-ureido group, etc.;

[0061]

[0062] The soft segment monomer 1 in the embodiment of the present invention is mainly an organic monomer containing an aliphatic alkylene group, an aromatic hydrocarbon group, or an ether group, and has the following structural characteristics, that is, R2 connects two mercapto groups (-SH), and is a dithiol monomer;

[0063]

[0064] R2 is selected from one or more of aliphatic alkylene groups, aromatic hydrocarbon groups and ether groups. Further, R2 is preferably a symmetric ether group. In some embodiments of the present invention, the first soft segment monomer shown in Formula 2 is specifically: HS-CH2-CH2-O-CH2-CH2-O-CH2CH2-SH.

[0065] Meanwhile, the soft segment monomer 2 has the following structural feature (CH2=CH-R3-CH=CH2); R3 is a group containing positive and negative ion pairs and is connected to the two terminal alkenyl groups.

[0066]

[0067] Preferably, R3 is a group containing imidazole ion pairs, pyridine ion pairs, quaternary ammonium salts or quaternary phosphonium salts. The present application has no special restrictions on the main chain lengths of the soft segments R2 and R3, and they can be long or short. In this work, the segments containing R2 and R3 are called soft segments mainly because the intermolecular forces of the groups obtained after the thiol-ene addition reaction between the thiol groups and the double bonds are very weak, so the two play the role of soft segments. While strong hydrogen bonds can be formed between R1 in the hard segments to achieve the function of the hard segment structure. The regulation of the hardness and softness properties of the final material in the embodiments of the present application is mainly aimed at the regulation of the molar ratio between the three units.

[0068] In some embodiments of the present invention, the structure of the second soft segment monomer shown in Formula 3 is specifically as follows:

[0069]

[0070] In the embodiments of the present invention, the hard segment monomer, the soft segment monomer 1 and the soft segment monomer 2 are mixed uniformly in a solvent, preferably a catalyst is added, and they are irradiated under ultraviolet light with a wavelength of 365 nm. The environmental temperature can be room temperature to polymerize to obtain the thermoplastic elastomer.

[0071] In the embodiments of the present invention, the monomers used can be commercially available or self-made. The molar ratio of the hard segment monomer, the soft segment monomer 1 and the soft segment monomer 2 is preferably (1~10):(2~21):(1~10), more preferably (1~9):(2~20):(1~9). The catalyst is preferably benzoin dimethyl ether, and the addition amount does not exceed 1 wt% of the total mass of the reactants. The solvent can be one or more of volatile organic solvents such as dichloromethane, chloroform, tetrahydrofuran, acetone, etc. Generally, its amount is controlled to be able to dissolve the reactants. In some specific embodiments, since the two soft segment monomers are liquids, a small amount of solvent is sufficient, and the monomer concentration is about 1 g / mL; the hard segment monomer is more difficult to dissolve and has a lower concentration, about 5 mg / mL.

[0072] The polymerization reaction temperature is preferably natural temperature (i.e., room temperature of 10 to 30° C., which is well known to those skilled in the art), the reaction pressure can be 1 atmosphere, and the reaction time is 2 to 2000 min, further 10 to 1000 min, such as 15 to 500 min, etc. After the irradiation, it can be left to stand naturally for 2 hours, and the product is a block-shaped solid soft material, and its shape depends on the mold.

[0073] The embodiment of the present invention utilizes light to carry out polymerization reaction, thereby realizing the simple preparation of the thermoplastic elastomer. In the above preparation process, the embodiment of the present invention imparts excellent strength and modulus to the elastomer through the hydrogen bonds or π-π interactions formed in the hard segment, or the synergistic effect of hydrogen bonds and π-π interactions, and obtains high resilience through the thermodynamic incompatibility between the two units of the soft segment; and obtains good electrical conductivity through the excellent ionic conductivity of the soft segment monomer 2. At the same time, the present invention can achieve effective control of the performance of the elastomer by changing the chemical structure and component ratio of each segment unit.

[0074] Experimental results show that the tensile strength of the high-strength, high-resilience, ion-conductive thermoplastic elastomer of the present invention can reach 30MPa, which is much higher than the reported related ion-conductive polymers; its elongation at break can reach more than 1000%, showing excellent toughness; when the uniaxial tensile deformation reaches a large deformation of 200%, it still has a fast deformation recovery ability and can achieve full recovery of strength within 1 minute; its resistance changes linearly with strain and can be used as a strain sensor.

[0075] In order to better understand the technical content of the present invention, specific examples are provided below to further illustrate the present invention. The reagents and materials described in the following examples, unless otherwise specified, can be obtained from commercial sources.

[0076] Example 1

[0077] A method for preparing a high-strength, high-resilience, ion-conductive thermoplastic elastomer comprises the following steps:

[0078] Will Figure 2 The hard segment monomers shown, Figure 3 The soft segment monomer 1 (commercially available) and Figure 4 The soft segment monomer 2 is mixed uniformly in a solvent according to a specific ratio, a catalyst is added (the amount added is 0.5wt% of the total weight of the monomer), and irradiated under 365nm wavelength ultraviolet light for 60min, the ambient temperature is room temperature, and the reaction pressure is 1 atmosphere. The selected solvent is tetrahydrofuran, the hard segment monomer concentration is 5mg / mL, and the total soft segment monomer concentration is 1g / mL.

[0079] Among them, the catalyst used is benzoin dimethyl ether; the molar ratio of the hard segment monomer to the soft segment monomer 1 is 1:2; the molar ratio of the hard segment monomer to the soft segment monomer 2 is 1:1.

[0080] Self-preparation process of the hard segment monomer:

[0081] Take 2-hydroxyethyl acrylate and hexamethylene diisocyanate (both are commercially available), dissolve them in tetrahydrofuran solution, the total monomer concentration is 10 mg / mL, where the molar ratio of 2-hydroxyethyl acrylate to hexamethylene diisocyanate is 2:1, and there is no catalyst. The reaction temperature is 60 °C, the reaction time is 2 h. After the reaction, wait for the solvent to evaporate completely before subsequent use.

[0082] Self-preparation process of the soft segment monomer 2:

[0083] Add dimethyldiallylammonium chloride and lithium bis(trifluoromethanesulfonyl)imide (both are commercially available and both are water-soluble) to deionized water, with a concentration of 0.5 g / mL, stir for 30 min, then precipitate it, and take the lower-layer precipitate; add it to deionized water again, with a concentration of 0.5 g / mL, stir for 30 min, then precipitate it. Repeat this 5 times to obtain the soft segment monomer 2. Among them, the molar ratio of dimethyldiallylammonium chloride to lithium bis(trifluoromethanesulfonyl)imide is 1:1.

[0084] Figure 2 is the 1H-NMR spectrum of the hard segment monomer, and the molecular structure is as follows, Figure 3 is the 1H-NMR spectrum of the soft segment monomer 1; Figure 4 is the 1H-NMR spectrum of the soft segment monomer 2;

[0085]

[0086] The structural characterization of the obtained thermoplastic elastomer is as Figure 5 shown by the product NMR; according to the NMR spectrum of the product, the characteristic peaks belonging to double bonds near 7.1 and 7.4 disappear, indicating that a chemical reaction has occurred between the hard segment unit and the two soft segment units, and the reaction is complete.

[0087] Perform performance tests according to the national standard method. The mechanical properties of the obtained thermoplastic elastomer are shown in Figure 6 ; the electrical conductivity is shown in Figure 7 , and the experiments of lighting the light bulb and strain sensing illustrate its electrical conductivity.

[0088] Example 2

[0089] A preparation method of a high-strength, high-elastic recovery, ion-conductive thermoplastic elastomer, comprising the following steps:

[0090] Put Figure 2 the hard segment monomer shown,Figure 3 The soft segment monomer 1 shown Figure 4 and the soft segment monomer 2 shown are mixed evenly in a solvent according to a specific ratio, a catalyst is added (the reaction conditions are the same as those in Example 1), and it is irradiated with ultraviolet light at a wavelength of 365 nm for 60 min. The ambient temperature is room temperature, and the reaction pressure is 1 atmosphere.

[0091] Among them, the catalyst used is benzoin dimethyl ether; the molar ratio of the hard segment monomer to the soft segment monomer 1 is 2:5; the molar ratio of the hard segment monomer and the soft segment monomer 2 is 2:3.

[0092] Figure 8 is the stress-strain curve of the elastomer. Obviously, the elastomer has obvious strain hardening behavior, and its strength can be as high as 32 MPa, showing the characteristics of high strength.

[0093] Figure 9 It shows the high resilience elasticity of the elastomer. The deformation rate is 100 mm / min, and the instantaneous residual strain after resilience is only about 10%. Considering that the maximum strain is 200%, the resilience efficiency is as high as 95%.

[0094] Example 3

[0095] A preparation method of a high-strength, high-resilience, ion-conductive thermoplastic elastomer, comprising the following steps:

[0096] Mix Figure 10 the hard segment monomer shown, Figure 3 the soft segment monomer 1 shown Figure 4 and the soft segment monomer 2 shown evenly in a solvent according to a specific ratio, a catalyst is added (the preparation conditions are the same as those in Example 1), and it is irradiated with ultraviolet light at a wavelength of 365 nm for 60 min. The ambient temperature is room temperature, and the reaction pressure is 1 atmosphere.

[0097] Among them, the catalyst used is benzoin dimethyl ether; the molar ratio of the hard segment monomer to the soft segment monomer 1 is 1:2; the molar ratio of the hard segment monomer and the soft segment monomer 2 is 1:1.

[0098] Figure 10 is the 1H-NMR spectrum of the hard segment monomer; the structural characterization of the obtained thermoplastic elastomer is as Figure 11 shown. According to the NMR spectrum of the product, the characteristic peaks belonging to double bonds near 7.1 and 7.4 disappear, indicating that a chemical reaction has occurred between the hard segment unit and the two soft segment units, and the reaction is complete.

[0099] Figure 12 is the stress-strain curve of the cyclic stretching of the elastomer. When stretched to a strain of 200%, the strain can be immediately restored after unloading the stress at this moment, and the strain residue rate is less than 15%, reflecting the characteristics of high resilience.

[0100] Example 4

[0101] A preparation method of a high-strength, high-rebound, ion-conductive thermoplastic elastomer, comprising the following steps:

[0102] Mix Figure 10 the shown hard-segment monomer, Figure 3 the shown soft-segment monomer 1 and Figure 4 the shown soft-segment monomer 2 in a specific ratio in a solvent uniformly, add a catalyst (the preparation conditions are the same as those in Example 1), place it under ultraviolet light with a wavelength of 365 nm for irradiation for 60 min, the environmental temperature is room temperature, and the reaction pressure is 1 atmosphere.

[0103] Among them, the catalyst used is benzoin dimethyl ether; the molar ratio of the hard-segment monomer to the soft-segment monomer 1 is 2:5; the molar ratio of the hard-segment monomer and the soft-segment monomer 2 is 2:3.

[0104] 13 is the curve of the resistance of the elastomer changing with strain. As the strain extends, the resistance shows an increasing trend, but its slope basically remains 1, that is, its response factor is 1, and it can be used as a strain sensor.

[0105] Comparative Example 1

[0106] A preparation method of a thermoplastic elastomer, comprising the following steps:

[0107] Mix Figure 2 the shown hard-segment monomer and Figure 3 the shown soft-segment monomer 1 in a specific ratio in a solvent uniformly, add a catalyst (the reaction conditions are the same as those in the above-mentioned example), place it under ultraviolet light with a wavelength of 365 nm for irradiation for 60 min, the environmental temperature is room temperature, and the reaction pressure is 1 atmosphere. Among them, the catalyst used is benzoin dimethyl ether; the molar ratio of the hard-segment monomer to the soft-segment monomer 1 is 1:1.

[0108] This elastomer lacks ionic units and thus cannot conduct ions, and the content of soft-segment units is relatively low, and its toughness is poor. Figure 14 is the NMR diagram of the obtained elastomer product; Figure 15 is the mechanical property diagram of the elastomer product obtained in the comparative example. According to Figure 15 , the soft-segment unit 2 is lacking in the comparative example, resulting in a fixed molar ratio of the hard-segment to the soft-segment unit 1, and the performance of the elastomer cannot be adjusted by adjusting the soft-segment ratio. Therefore, it shows a relatively small elongation at break, and the elastomer presents a brittle characteristic.

[0109] Comparative Example 2

[0110] A preparation method of a thermoplastic polymer, comprising the following steps:

[0111] Mix Figure 2The shown hard segment monomer and Figure 4 The shown soft segment monomer 2 are mixed evenly in a solvent in a specific ratio, a catalyst is added (the reaction conditions are the same as those in the above embodiments), and it is irradiated with ultraviolet light at a wavelength of 365 nm for 60 min. The ambient temperature is room temperature, and the reaction pressure is 1 atmosphere. Among them, the catalyst used is benzoin dimethyl ether; the molar ratio of the hard segment monomer to the soft segment monomer 1 is 1:1.

[0112] The structural characterization of this polymer is as Figure 16 shown; the product is powdery and brittle, and mechanical tests cannot be carried out. Due to the restricted movement of ionic groups, ionic conduction cannot be carried out either.

[0113] According to the above embodiments and the like, it can be known that the tensile strength of the thermoplastic elastomer material prepared by the present invention can reach 30 MPa, which is much higher than the reported related ion-conductive polymers; its elongation at break can reach more than 1000%, showing excellent toughness; when the uniaxial tensile strain reaches a large strain of 200%, it still has the ability to quickly recover from deformation, and can achieve complete recovery of strength within 1 min; its resistance changes linearly with strain and can be used as a strain sensor. In the preparation process of the embodiments of the present invention, by changing the chemical structure and component ratio of each segment unit, the performance of the elastomer can be effectively controlled. The present invention can carry out polymerization reaction by light irradiation, making the preparation of this thermoplastic elastomer simple and conducive to application.

[0114] The above description of the disclosed embodiments enables those skilled in the art to implement or use the present invention. Various modifications to these embodiments will be obvious to those skilled in the art, and the general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to these embodiments shown herein, but rather to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A high-strength, high-rebound ionic conductive thermoplastic elastomer, characterized in that, It includes a hard segment unit with the structure shown in Formula I and a soft segment unit with the structure shown in Formula II; Formula I; Formula II; Among them, R1 is selected from one or two of a substituted urea group and a urethane group; R2 is selected from ether groups; R3 is a group containing an imidazole ion pair, a pyridine ion pair, a quaternary ammonium salt or a quaternary phosphonium salt; The molar ratios of the respective monomers corresponding to R1, R2, and R3 are (1 to 10):(2 to 21):(1 to 10).

2. The ionic conductive thermoplastic elastomer according to claim 1, wherein R1 is selected from one or two of an aliphatic chain biurea group and a dicarbamate group; R2 is selected from a symmetrical ether group.

3. The preparation method of the ionic conductive thermoplastic elastomer according to any one of claims 1-2, comprising the following steps: Polymerize the hard segment monomer shown in Formula 1, the first soft segment monomer shown in Formula 2, and the second soft segment monomer shown in Formula 3 to obtain the ionic conductive thermoplastic elastomer; Formula 1; Formula 2; Formula 3; Among them, R1 is selected from one or two of a substituted urea group and a urethane group; R2 is selected from ether groups; R3 is a group containing an imidazole ion pair, a pyridine ion pair, a quaternary ammonium salt or a quaternary phosphonium salt.

4. The preparation method according to claim 3, characterized in that, The specific preparation method is as follows: Dissolve the hard segment monomer shown in Formula 1, the first soft segment monomer shown in Formula 2, and the second soft segment monomer shown in Formula 3 in a solvent, and carry out a polymerization reaction under ultraviolet light with a wavelength of 365 nm for a certain period of time to obtain the ionic conductive thermoplastic elastomer.

5. The preparation method according to claim 4, characterized in that, The molar ratios of the hard segment monomer, the first soft segment monomer, and the second soft segment monomer are (1 to 10):(2 to 21):(1 to 10).

6. The preparation method according to claim 4, characterized in that, The solvent is a volatile organic solvent, which is one or more of dichloromethane, chloroform, tetrahydrofuran, and acetone.

7. The preparation method according to any one of claims 4-6, characterized in that, The polymerization reaction is carried out under the condition of adding a catalyst.

8. The preparation method according to claim 7, characterized in that, The catalyst is benzoin dimethyl ether, and the addition amount does not exceed 1 wt% of the total mass of the reactants.

9. The preparation method according to claim 7, characterized in that, The temperature of the polymerization reaction is the natural temperature, the reaction time is 2 to 2000 min; the reaction pressure is 1 atmosphere.

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