Intrinsic Elastic Semiconductor Materials Based on Imine Block Copolymers and Preparation Methods Thereof

Abstract

The present invention provides an intrinsic elastic semiconductor material based on an imine block copolymer and a preparation method thereof. The preparation method comprises the following steps: using an aldehyde group-terminated conjugated oligomer and an amino group-terminated non-conjugated compound as raw materials, and through an aldehyde-amine polycondensation reaction under the action of an acid catalyst, an intrinsic elastic semiconductor material based on an imine block copolymer is obtained. In the present invention, the aldehyde group-terminated conjugated oligomer structure is used as the hard segment, and the amino group-terminated non-conjugated compound is used as the soft segment. An elastic semiconductor material based on an imine block copolymer is prepared through an aldehyde-amine polycondensation reaction. This method has the advantages of mild reaction conditions, high atomic economy utilization rate, and simple separation and purification of the product; the intrinsic elastic semiconductor material of the present invention has high mobility and good tensile properties, and has important application potential in flexible / elastic wearable devices.

Description

Technical Field

[0001] The present invention relates to the technical field of organic semiconductor chemical synthesis, and more particularly, to an intrinsically elastic semiconductor material based on an imine block copolymer and a preparation method thereof. Background Art

[0002] With the rapid development of the intelligent Internet of Things, many flexible / elastic electronic devices such as electronic skin and implantable medical devices have become increasingly closely related to people. These devices work on or inside the human body surface and need to have mechanical properties that match human tissues. As an important basic material for flexible / elastic electronic devices, the elasticization of semiconductors is of great significance. Compared with inorganic semiconductors, polymer semiconductors have the advantages of adjustable chemical structure, solution processability, and good ductility. However, the mechanical properties of polymer semiconductors still cannot meet the strain requirements of human tissues, which greatly limits the development of flexible / elastic wearable devices. In view of this, the preparation of elastic semiconductors plays an important role in promoting the development of flexible / elastic electronic devices.

[0003] At present, the design and synthesis of block copolymers for the preparation of elastic semiconductors is a research hotspot in the semiconductor field. Reactions such as Stille coupling, ATRP radical polymerization, and azide click reaction have been used to prepare elastic semiconductors of block copolymers. For example, the Qiu team prepared a block copolymer elastic semiconductor based on isoindigo derivatives by Stille coupling reaction. This reaction process requires the participation of organotin compounds, which are highly harmful to the human body and cause serious environmental pollution (J. Mater. Chem. C, 2019, 7, 11639). The Jadranka team prepared a block copolymer elastic semiconductor based on P3HT by ATRP radical polymerization reaction. In this reaction process, a large amount of transition metal complex is used and it is not consumed during the polymerization process, resulting in problems such as cumbersome separation and purification of reaction products (Chem. Mater. 2017, 29, 8850 - 8858). Chen and his colleagues prepared a block copolymer elastic semiconductor based on isoindigo thiophene by Stille coupling reaction (Macromolecules. 2017, 50, 4982 - 4992). The Toshifumi team reported an elastic semiconductor of P3HT block copolymer prepared based on azide click reaction, but azide compounds are flammable, explosive and highly dangerous (Macromolecules. 2017, 50, 1442 - 1452). In recent years, the Franziska team prepared a block copolymer elastic semiconductor based on DPP by Stille coupling reaction (Adv. Mater. 2021, 33, 2005416). Thus, although certain progress has been made in the preparation of current elastic semiconductors based on block copolymers, the above reactions require the participation of highly toxic stannanes, azide compounds or transition metal complexes, and there are problems such as harsh reaction conditions, environmental pollution and cumbersome separation and purification of products. Therefore, it is very necessary to find a reaction with the advantages of green chemical synthesis to prepare elastic semiconductor materials of block copolymers. Summary of the Invention

[0004] Aiming at the deficiencies of the prior art, the purpose of the present invention is to provide a preparation method of an intrinsic elastic semiconductor material with mild reaction conditions, high atomic economy utilization rate, and simple separation and purification of products.

[0005] The present invention provides a preparation method of an intrinsic elastic semiconductor material based on imine block copolymer, comprising the following steps: using an aldehyde group-terminated conjugated oligomer and an amino group-terminated non-conjugated compound as raw materials, and through aldehyde-amine polycondensation reaction under the action of an acid catalyst, an intrinsic elastic semiconductor material based on imine block copolymer is obtained, as shown in structural formula I:

[0006]

[0007] In structural formula I: n, m are natural numbers.

[0008] Further, the preparation method includes the following steps:

[0009] S1. Add the aldehyde group-terminated conjugate compound and the amino group-terminated conjugate compound into a reaction vessel, then add an acid catalyst, introduce an inert gas to expel the air in the reaction vessel, add a reaction solvent, and carry out an aldehyde-amine polycondensation reaction at a certain temperature to obtain an aldehyde group-terminated conjugate oligomer;

[0010] S2. Add the amino group-terminated non-conjugated compound into the reaction solution of the aldehyde group-terminated conjugate oligomer to continue the reaction. After the reaction is completed, precipitate, extract, and purify the reaction solution to obtain the intrinsic elastic semiconductor material based on the imine block copolymer.

[0011] Further, the aldehyde group-terminated conjugate compound has a general structural formula shown in Structural Formula II:

[0012] OHC-Ar1-CHO

[0013] Structural Formula II

[0014] In Structural Formula II, Ar1 is a conjugated structure having a relatively high hole mobility, electron mobility, or both hole and electron mobilities. For example: the conjugated structure of acenes and their derivatives, heteroatom-substituted organic conjugated aromatic hydrocarbons, the conjugated structure of thiophenes, conjugated macrocycles, the conjugated structure of fullerenes and their derivatives, the conjugated structure of perylene / naphthalimide derivatives, the conjugated structure substituted with electron-withdrawing groups such as fluorine atoms, cyano groups, amide groups, etc. Preferably, it is a conjugated structure terminated with two aldehyde groups having good solubility, so as to obtain an imine block copolymer with good solubility and high molecular weight under the reaction conditions.

[0015] Further, the amino group-terminated conjugate compound has a general structural formula shown in Structural Formula III:

[0016] H2N-Ar2-NH2

[0017] Structural Formula III

[0018] In Structural Formula III, Ar2 is a conjugated structure having a relatively high hole mobility, electron mobility, or both hole and electron mobilities. For example: the conjugated structure of acenes and their derivatives, heteroatom-substituted organic conjugated aromatic hydrocarbons, the conjugated structure of thiophenes, conjugated macrocycles, the conjugated structure of fullerenes and their derivatives, the conjugated structure of perylene / naphthalimide derivatives, the conjugated structure substituted with electron-withdrawing groups such as fluorine atoms, cyano groups, amide groups, etc. Preferably, it is an amino group-terminated conjugated structure such as p-phenylenediamine, amino derivatives of pyrrolopyrrolidone, etc.

[0019] Further, the amino-terminated non-conjugated compound is selected from one or more of elastomers such as amino-terminated polydimethylsiloxane, amino-terminated polyamide, and amino-terminated polycaprolactone polyol, preferably an amino-terminated elastomer with a molecular weight between 3000 and 7000.

[0020] Further, in the step S1, the molar ratio of the aldehyde-terminated conjugated compound to the amino-terminated conjugated compound is 1.1 - 1.9:1; in the step S2, the molar ratio of the amino-terminated non-conjugated compound to the aldehyde-terminated conjugated oligomer is 0.1 - 0.9:1, preferably 0.4 - 0.7:1.

[0021] Further, the acid catalyst is selected from one or more of p-toluenesulfonic acid, lithium chloride (LiCl3), calcium chloride (CaCl2), cuprous iodide (CuI), and acidic ionic liquids. The mass fraction of the acid catalyst in the reaction system is 5 - 15 wt.%.

[0022] Further, the reaction solvent is selected from one of conventional solvents such as tetrahydrofuran, methanol, ethanol, dichloroethane, toluene, chlorobenzene, xylene, pyridine, and dimethylformamide.

[0023] Further, in the step S1, the reaction temperature is 50 - 200 °C, the reaction temperature is selected near the boiling point of the used reaction solvent, preferably 90 - 130 °C, and the reaction time is 10 - 24 h; in the step S2, the reaction temperature is 50 - 200 °C, preferably 90 - 130 °C, and the reaction time is 24 - 48 h.

[0024] The reaction process of the above preparation method is shown in Reaction Scheme I:

[0025]

[0026] The intrinsic elastic semiconductor material based on the imine block copolymer prepared by the above method has high mobility and good tensile properties, with an elongation at break greater than or equal to 300%; at a strain of 50%, the carrier mobility is greater than or equal to 1.0 cm 2 ·V -1 ·s -1 .

[0027] Compared with the prior art, the present invention has the following beneficial effects:

[0028] The present invention uses an aldehyde-terminated conjugated oligomer structure as the hard segment and an amino-terminated non-conjugated compound as the soft segment to prepare an elastic semiconductor material based on an imine block copolymer through an aldehyde-amine polycondensation reaction. This method has the advantages of mild reaction conditions, high atomic economy utilization rate, and simple product separation and purification.

[0029] The intrinsic elastic semiconductor material prepared by the present invention has high mobility and good tensile properties, and has important application potential in flexible / elastic wearable devices. Description of the Drawings

[0030] Figure 1 It is the reaction formula for the preparation process of the intrinsic elastic semiconductor material based on imine block copolymer in the specific embodiment of the present invention;

[0031] Figure 2 It is the reaction formula for the preparation process of the imine block copolymer in Example 1;

[0032] Figure 3 It is the nuclear magnetic resonance hydrogen spectrum of the imine block copolymer prepared in Example 1;

[0033] Figure 4 It is the absorption spectrum in the ultraviolet-visible light region of the imine block copolymer prepared in Example 1 in chlorobenzene solution;

[0034] Figure 5 It is the energy band gap of the imine block copolymer prepared in Example 1;

[0035] Figure 6 It is the thermogravimetric analysis spectrum of the imine block copolymer prepared in Example 1;

[0036] Figure 7 It is the stress-strain curve of the intrinsic elastic semiconductor material prepared in Example 2;

[0037] Figure 8 It is the stress-strain cyclic curve of the intrinsic elastic semiconductor material prepared in Example 2. Detailed Description of the Invention

[0038] To make the above objects, features, and advantages of the present invention more obvious and understandable, the following specific embodiments of the present invention will be described in detail with reference to the drawings. It should be noted that the following embodiments are only used to illustrate the implementation methods and typical parameters of the present invention, and are not used to limit the parameter range described in the present invention. Reasonable changes derived therefrom are still within the protection scope of the claims of the present invention.

[0039] It should be noted that the endpoints and any values within the ranges disclosed in this document are not limited to the exact ranges or values. These ranges or values should be understood to include values close to these ranges or values. For numerical ranges, between the endpoint values of each range, between the endpoint values of each range and individual point values, and between individual point values can be combined with each other to obtain one or more new numerical ranges, and these numerical ranges should be regarded as specifically disclosed in this document.

[0040] A specific embodiment of the present invention provides an intrinsically elastic semiconductor material based on an imine block copolymer, and its chemical structure is shown in the following formula I:

[0041]

[0042] In formula I: n and m are natural numbers.

[0043] The preparation method of the above-mentioned intrinsically elastic semiconductor material based on an imine block copolymer includes the following steps: using an aldehyde group-terminated conjugated compound and an amino group-terminated conjugated compound as raw materials, and obtaining an aldehyde group-terminated conjugated oligomer through an aldehyde-amine polycondensation reaction under the action of an acid catalyst; the aldehyde group-terminated conjugated oligomer then reacts with an amino group-terminated non-conjugated compound to obtain an imine block copolymer, and the reaction process is as Figure 1 shown.

[0044] After the reaction is completed, the reaction solution is precipitated, extracted and purified to obtain an intrinsically elastic semiconductor material based on an imine block copolymer.

[0045] In the above preparation method, the aldehyde group-terminated conjugated compound has a conjugated structure with relatively high hole mobility, electron mobility or both hole and electron mobilities, such as the conjugated structures of acenes and their derivatives, heteroatom-substituted organic conjugated aromatics, the conjugated structures of thiophenes, conjugated macrocycles, the conjugated structures of fullerenes and their derivatives, the conjugated structures of perylene / naphthalimide derivatives, and conjugated structures substituted with electron-withdrawing groups such as fluorine atoms, cyano groups, and amide groups. The general structural formula of the aldehyde group-terminated conjugated compound is shown in structural formula II.

[0046] OHC-Ar1-CHO

[0047] Structural formula II

[0048] Preferably, the aldehyde group-terminated conjugated compound has good solubility, so as to obtain an imine block copolymer with good solubility and high molecular weight under the reaction conditions.

[0049] In the above preparation method, the amino group-terminated conjugated compound has a conjugated structure with relatively high hole mobility, electron mobility or both hole and electron mobilities, such as the conjugated structures of acenes and their derivatives, heteroatom-substituted organic conjugated aromatics, the conjugated structures of thiophenes, conjugated macrocycles, the conjugated structures of fullerenes and their derivatives, the conjugated structures of perylene / naphthalimide derivatives, and conjugated structures substituted with electron-withdrawing groups such as fluorine atoms, cyano groups, and amide groups. The general structural formula of the amino group-terminated conjugated compound is shown in structural formula III.

[0050] H2N-Ar2-NH2

[0051] Structural formula III

[0052] As a preferred embodiment, the amino-terminated conjugated compound is an amino derivative of p-phenylenediamine or pyrrolopyrrole dione.

[0053] In the above preparation method, the acid catalysts mainly include p-toluenesulfonic acid, acidic ionic liquid, LiCl3, CaCl2, CuI, etc. One or two acid catalysts are selected to avoid too fast deactivation of the catalyst and to be able to remove the by-products in the reaction in time, so that under the reaction conditions, a high molecular weight imine block copolymer can be generated.

[0054] In the above preparation method, the amino-terminated non-conjugated compounds mainly include elastomers such as amino-terminated polydimethylsiloxane, amino-terminated polyamide, and amino-terminated polycaprolactone polyol. Preferably, the molecular weight of the non-conjugated compound is 3000-7000.

[0055] In the above preparation method, the reaction solvents used are conventional solvents such as tetrahydrofuran, methanol, dichloroethane, ethanol, toluene, chlorobenzene, pyridine, and dimethylformamide.

[0056] In the above preparation method, the temperature of the aldehyde-amine polycondensation reaction is selected in the range near the boiling point of the solvent used, that is, between 50 and 200 °C.

[0057] The specific operation process of the above preparation method is as follows: Weigh 20-55 wt.% of aldehyde-terminated conjugated compound, 5-35 wt.% of amino-terminated conjugated compound, and 5-15 wt.% of acid catalyst and place them into a Schlenk reaction tube for gas replacement treatment; then add 0.5-5 ml of anhydrous and oxygen-free solvent to the reaction tube, and carry out the aldehyde-amine polycondensation reaction at 50-200 °C to fully react to obtain aldehyde-terminated conjugated oligomer; finally, add 10-75 wt.% of amino-terminated soft segment non-conjugated compound to the conjugated oligomer reaction solution for aldehyde-amine polycondensation reaction, and after full reaction, an imine block copolymer is obtained; after the reaction is completed, the reaction solution is precipitated, extracted and purified to obtain the intrinsic elastic semiconductor material based on the imine block copolymer.

[0058] In the above preparation method, the reaction activity of aliphatic amines is low, and it is difficult to carry out polycondensation reaction, resulting in a small molecular weight of the generated imine block copolymer. By adjusting reaction parameters such as reaction temperature and solvent addition amount, the energy application density is increased to improve the reaction activity of aliphatics, so as to ensure the molecular weight of the imine block copolymer.

[0059] In the above reaction, the by-product is low-molecular-weight water. Selecting a suitable desiccant to timely remove the by-products in the reaction system is an effective method to improve the reaction yield. As a preferred embodiment, desiccants such as CaCl2 and MgSO4 are added to the system, and the by-products generated during the synthesis of the imine block copolymer by the aldehyde-amine polycondensation reaction can be removed in a timely manner, so that the molecular weight of the imine block copolymer is increased.

[0060] In the above preparation method, the process of preparing the imine block copolymer by the aldehyde-amine polycondensation reaction is carried out in a liquid-phase reaction. As a preferred embodiment, the reaction temperature is controlled at 50-200 °C, preferably 90-130 °C.

[0061] As a preferred embodiment, the molar ratio of the aldehyde group-terminated conjugate compound to the amino group-terminated conjugate compound is 1.1-1.9:1; the molar ratio of the amino group-terminated non-conjugated compound to the aldehyde group-terminated conjugate oligomer is 0.1-0.9:1, preferably 0.4-0.7:1.

[0062] Example 1

[0063] Thiophene dialdehyde A and bis(amino)-terminated pyrrolopyrrole dione B (NH2-DPP-NH2) with a molar ratio of 1.3:1 were added to a Schlenk reaction tube, and a mixed catalyst of toluenesulfonic acid and calcium chloride was added. After displacing the gas and introducing an inert gas to discharge the air in the reaction vessel, the reaction solvent chlorobenzene was added. The catalyst in the system accounted for 10 wt.% of the reactants; the reaction was carried out at 95-130 °C for 10-24 h to obtain the conjugate oligomer C. The weighed bis(amino)-terminated polydimethylsiloxane D with a mass fraction of 30 wt.% was added to the above conjugate oligomer C reaction solution, and the reaction was continued for 24-48 h to obtain the imine block copolymer E. The reaction process is as Figure 2 shown.

[0064] After the reaction was completed, the product was cooled to room temperature and precipitated in methanol, and then filtered to obtain the crude product. After Soxhlet extraction with methanol, acetone and n-hexane, it was precipitated in methanol again and dried in a vacuum drying oven.

[0065] The final product was characterized by nuclear magnetic resonance, and the results are as Figure 3 shown. The 1H nuclear magnetic resonance spectrum showed the chemical shift of the final product, and the results indicated that the intrinsic elastic semiconductor material of the imine block copolymer based on the aldehyde-amine polycondensation reaction was successfully synthesized.

[0066] The photophysical properties of the final product imine block copolymer were characterized by an ultraviolet-visible spectrophotometer, Figure 4 which is the absorption spectrum of the imine block copolymer in a chlorobenzene solvent, covering the visible region of 300-600 nm. As Figure 5As shown, the maximum absorption wavelength of the imine block copolymer is 625 nm, and its Eg is 1.78 eV.

[0067] The thermal stability of the imine block copolymer was analyzed by thermogravimetric analysis. As Figure 6 shown, the thermogravimetric curve of the imine block copolymer in the temperature range of 20 - 800 °C at room temperature shows that the initial weight loss temperature of the imine block copolymer is 380 °C, indicating that the imine block copolymer has good thermal stability.

[0068] The mechanical properties of the intrinsic elastic semiconductor material were tested using a universal tensile machine, and its elongation at break was 320 ± 15%.

[0069] The carrier mobility of the intrinsic elastic semiconductor material was tested. At a strain of 50%, the carrier mobility was 1.5 cm 2 ·V -1 ·s -1 , indicating high mobility.

[0070] Example 2

[0071] Aldehyde - terminated pyrrolopyrrole dione and amino - terminated PDMS with a molar ratio of 1.5:1 were respectively placed in a Schlenk reaction tube. A mixed catalyst of p - toluenesulfonic acid and calcium chloride was added. After displacing the gas, the reaction solvent dioxane was added, and an inert gas was introduced to remove the air in the reaction vessel. The catalyst in the system accounted for 15 wt.% of the reactants. The reaction was carried out at 90 - 110 °C for 12 - 48 h to obtain the imine block copolymer. The chemical structural formula of the imine block copolymer is as follows:

[0072]

[0073] After the reaction ended, the product was cooled to room temperature and precipitated in methanol, then filtered by suction to obtain the crude product. After Soxhlet extraction with methanol, acetone, and n - hexane, it was precipitated again in methanol and dried in a vacuum drying oven to obtain the intrinsic elastic semiconductor material.

[0074] The stress - strain curve of the imine block copolymer was characterized using a universal tensile machine. As Figure 7 shown, its elongation at break was 330 ± 30%, and the elastic modulus was 3.2 ± 0.6 MPa; in a 120% tensile cycle as Figure 8 shown, it exhibited good tensile properties.

[0075] The carrier mobility of the intrinsic elastic semiconductor material was tested. At a strain of 50%, the carrier mobility was 1.4 cm 2 ·V -1 ·s -1 , indicating high mobility.

[0076] Although the present invention is disclosed as above, the present invention is not limited thereto. Any person skilled in the art can make various changes and modifications without departing from the spirit and scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the scope defined by the claims.

Claims

1. A preparation method of an intrinsically elastic semiconductor material based on an imine block copolymer, characterized in that, Comprising the following steps: Using an aldehyde-terminated conjugated oligomer and an amino-terminated non-conjugated compound as raw materials, under the action of an acid catalyst, through an aldehyde-amine polycondensation reaction, an intrinsic elastic semiconductor material based on an imine block copolymer is obtained, as shown in Structural Formula I: Structural formula I In Structural Formula I: n and m are natural numbers; Ar1 is a conjugated structure of thiophene; Ar2 is a conjugated structure containing an amide group; The acid catalyst is selected from one or more of p-toluenesulfonic acid and acidic ionic liquids; The amino-terminated non-conjugated compound is selected from one or more of polydimethylsiloxane terminated with double amino groups, polyamide terminated with double amino groups, and polycaprolactone polyol terminated with double amino groups.

2. The preparation method of the intrinsic elastic semiconductor material based on imine block copolymer according to claim 1, characterized in that, Comprising the following steps: S1. Add the aldehyde-terminated conjugated compound and the amino-terminated conjugated compound into a reaction vessel, then add an acid catalyst, introduce an inert gas to discharge the air in the reaction vessel, add a reaction solvent, and carry out an aldehyde-amine polycondensation reaction at a certain temperature to obtain an aldehyde-terminated conjugated oligomer; S2. Add the amino-terminated non-conjugated compound to the reaction solution of the aldehyde-terminated conjugated oligomer and continue the reaction. After the reaction is completed, precipitate and extract and purify the reaction solution to obtain an intrinsic elastic semiconductor material based on an imine block copolymer.

3. The preparation method of the intrinsic elastic semiconductor material based on imine block copolymer according to claim 2, characterized in that, The aldehyde-terminated conjugated compound has a structural general formula as shown in Structural Formula II: Structural formula II.

4. The preparation method of the intrinsic elastic semiconductor material based on imine block copolymer according to claim 2, characterized in that, The amino-terminated conjugated compound has a structural general formula as shown in Structural Formula III: Structural formula III.

5. The preparation method of the intrinsic elastic semiconductor material based on imine block copolymer according to any one of claims 2-4, characterized in that, In step S1, the molar ratio of the aldehyde-terminated conjugated compound to the amino-terminated conjugated compound is 1.1 - 1.9:

1. In step S2, the molar ratio of the amino-terminated non-conjugated compound to the aldehyde-terminated conjugated oligomer is 0.1 - 0.9:

1.

6. The preparation method of the intrinsic elastic semiconductor material based on an imine block copolymer according to claim 5, characterized in that, The reaction solvent is selected from one of tetrahydrofuran, methanol, ethanol, dichloroethane, toluene, chlorobenzene, xylene, pyridine, and dimethylformamide.

7. The preparation method of the intrinsic elastic semiconductor material based on imine block copolymer according to claim 6, characterized in that, In step S1, the reaction temperature is 50 - 200 °C and the reaction time is 10 - 24 h. In step S2, the reaction temperature is 50 - 200 °C and the reaction time is 24 - 48 h.

8. An intrinsically elastic semiconductor material based on an imine block copolymer, characterized in that, Obtained by the preparation method according to any one of claims 1 - 7.

9. The intrinsic elastic semiconductor material based on an imine block copolymer according to claim 8, wherein Its elongation at break is greater than or equal to 300%; at a strain of 50%, the carrier mobility is greater than or equal to 1.0 cm 2 ·V −1 ·s −1 。

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