Main-chain conjugated intrinsically stretchable electroluminescent elastomer and preparation and application thereof

Abstract

The application belongs to the technical field of photoelectric materials and application, and discloses a main chain conjugated intrinsic stretchable electroluminescent elastomer and preparation and application thereof. The elastomer is prepared by taking a conjugated structure with excellent photoelectric performance as a rigid main chain and polyacrylate as a flexible side chain through a free radical polymerization reaction. The innovation of the application is that the flexible acrylate side chain is introduced into the rigid light-emitting conjugated main chain in a chemical crosslinking manner to form a rod-shaped bottle brush structure, so that the elastomer has excellent photoelectric properties on the basis of improving the intrinsic stretchability of the elastomer; the structure is novel, the design strategy is unique, and the problems of intrinsic non-stretchability of traditional conjugated light-emitting materials and the problem of high-performance photoelectric properties not possessed by traditional elastomers are solved at the same time; the elastomer is used as a light-emitting layer material to prepare an organic optoelectronic device with high stability, high stretchability and high efficiency.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of optoelectronic materials and applications, and particularly relates to design, synthesis and application of a main-chain conjugated intrinsic stretchable electroluminescent elastomer. BACKGROUND

[0002] Flexible stretchable electronic products have a wide application prospect, especially for wearable and implantable devices, so it is increasingly concerned by the academic and industrial circles. In recent years, flexible stretchable electronic products with high elasticity and ductility have been rapidly developed, and have significantly improved our daily life, indirectly leading the research of the academic and industrial circles to wearable electronic products, medical monitoring devices and electronic skin. For these applications, high-performance flexible and stretchable light-emitting polymer semiconductor materials capable of adapting to mechanical deformation are needed to meet the soft, dynamic and curved human body. Compared with traditional inorganic materials, organic electroluminescent materials can be prepared into flexible, large-area, patterned organic optoelectronic devices by solution method, which greatly meets the needs of modern science and technology. Since the discovery of conductive polymers in 1977, conjugated polymers (CPs) have attracted much attention due to their good processability, structure adjustability and application potential in various optoelectronic devices. Conjugated polymers can be used to manufacture electronic devices with lightweight, low cost and large area, such as organic light-emitting diodes (OLEDs), organic photovoltaics (OPVs) and organic field-effect transistors (OFETs).

[0003] Since the invention of OLEDs in 1987, continuous improvement and innovation of the light-emitting functional layer have led to rapid development of OLED technology. In 1992, researchers first reported flexible OLEDs by using poly(1,4-phenylene-vinylene) as the light-emitting layer, but due to the limitation of the spin-orbit theory of excitons, the external quantum efficiency was only about 1%. Researchers have almost always focused on the flexibility of OLED devices, because flexible OLEDs have low power consumption and excellent mechanical flexibility, and can be mass-produced and reused. Due to the great demand for commercialization of OLEDs, the development of flexible stretchable OLEDs has great potential. In order to enable OLED devices to maintain good performance during stretching, in addition to optimizing the device structure and preparation process, designing and synthesizing intrinsic stretchable electroluminescent materials to prepare stretchable optoelectronic devices is of great significance.

[0004] Polymer semiconductors have become important candidates for flexible and stretchable electronics, and various approaches have been developed to improve the electrical and mechanical properties of these conjugated polymers. However, current conjugated materials tend to be less flexible, causing thin film breakage during stretching, thus destroying the optoelectronic performance of the devices. The research of intrinsically stretchable polymer semiconductors focuses on the structure-property relationship between molecular design and thin film properties. A general strategy to improve the stretchability of polymer semiconductor materials is to achieve the optimization of thin film microstructure through molecular engineering, in which the balanced distribution of crystalline and amorphous regions is important. The introduction of appropriate CBs on the polymer backbone can achieve this microstructure of the thin film, which endows it with stretchability through energy dissipation mechanisms, and self-healing performance through hydrogen bonding CBs. So far, polymer films have shown cracks at more than ε = 100% when solidified under strain, while maintaining a carrier mobility of 1 cm 2 V -1 s -1 The above is achieved by combining hydrogen-bonded PDCA CBs in DPP-based D-A polymers. Effectively improving carrier transport and mechanical compliance, the interchain interactions of semiconducting polymers can also be adjusted by changing the side chains.

[0005] Precise morphology control is important for the further development of intrinsically stretchable polymer semiconductors. In addition to the proper distribution of crystalline and amorphous regions, the interpenetration of fibrous and entangled high-Mn connecting chains between deformable amorphous regions is an important factor for efficient charge transport. By regulating the Mn and the regioregularity of the polymer properties, as well as the structural modification of the polymer backbone and side chains, the morphology of the thin film can be changed. With the development of synthetic chemistry and processing technology, fine control of these parameters will help to realize practical devices.

[0006] In order to obtain stretchable CPs thin films without sacrificing optoelectronic performance, rational design of polymers through backbone and side chain engineering is usually the preferred method. Müller et al. [1] proved that a semiconducting diblock copolymer of polyethylene (PE) and regioregular poly(3-hexylthiophene) (P3HT) has excellent flexibility, with an elongation at break of more than 600% and a tensile modulus of about 70 MPa, opening up the way for the development of intrinsically stretchable CPs. Since then, copolymerization with "flexible connectors" containing aliphatic chains has been used to optimize the film morphology and reduce the melting temperature of CPs. Regarding side chain engineering, researchers have thoroughly studied the role of side chain structure in controlling polymer chain interactions and solution processability. Shinohara et al. [2]A viscoelastic CPs variant was developed by using flexible branched alkyl groups as "internal plasticizers", and the viscous CPs with an alkyl / ratio of 68:32 could be elongated up to 800%. However, if only a large number of alkyl chains are embedded in the CPs structure, it is not conducive to the thermal stability of the film morphology. On the other hand, based on the nano-confinement theory, blending with an elastic polymer is also a viable strategy. Xu et al. proved that [3] After mixing DPPT-TT with a commonly used elastomer (SEBS), the elastic modulus of the constrained film is sharply reduced, and can be stretched to 100% without reducing the charge carrier mobility. It is well known that blending with an elastomer can make the film stretchable, but it is still a difficult task to avoid the phase separation between the semiconductor polymer and the inert polymer matrix while achieving a balance between electroluminescent performance and mechanical performance.

[0007] [1]Müller C,Goffri S,Breiby DW,et al.Tough,semiconductingpolyethylene-poly

[0008] (3-hexylthiophene)diblock copolymers.Adv Funct Mater 2007;17:2674–9.

[0009] [2]A.Shinohara,C.Pan,Z.Guo,L.Zhou,Z.Liu,L.Du,Z.Yan,F.J.Stadler,L.Wang,T.

[0010] Nakanishi,Angew.Chem.Int.Ed.2019,58,9581.

[0011] [3]Xu J,Wang S,Wang G-J,et al.Highly stretchable polymersemiconductor films through thenanoconfinement effect.Science 2017;355:59–64. SUMMARY

[0012] In view of the aforementioned technical problems in the prior art, this invention discloses a method for preparing a main-chain conjugated intrinsically stretchable electroluminescent elastomer and its application as a light-emitting layer material in organic electroluminescent devices. This type of elastomer is prepared by free radical polymerization using a conjugated structure with excellent photoelectric properties as the rigid main chain and polyacrylate as the flexible side chain. This elastomer is used to prepare the light-emitting layer of intrinsically stretchable electroluminescent devices, achieving the fabrication of stretchable optoelectronic devices with high stretchability and high stability. This provides a new technical solution for realizing electroluminescence from traditional elastomers and for solving the intrinsic non-stretchability problem of traditional conjugated fluorescent materials.

[0013] The technical solution adopted in this invention is as follows:

[0014] This invention provides a main-chain conjugated intrinsically stretchable electroluminescent elastomer, which has the following general structural formula:

[0015]

[0016] Where m and n represent the number of repeating units of the component, Ar represents the conjugated structure, and ACR represents the acrylate side chain.

[0017] In a further technical solution, the conjugated structure represented by Ar is selected from one or more of the following molecular structures:

[0018]

[0019] Where R is C1-C 20 The straight or branched alkyl or alkoxy chain, * indicates the connection site.

[0020] In a further technical solution, the acrylate side chain represented by ACR has one of the following molecular structures:

[0021] Where R' is C1-C 10 Straight-chain or branched alkyl groups.

[0022] This invention also provides a method for preparing the above-mentioned main-chain conjugated intrinsically stretchable electroluminescent elastomer, the method comprising: a first step using monomers Using 4,7-dibromo-5-fluoro-2,1,3-benzothiadiazole as a starting material, a rigid backbone with a donor-acceptor structure was constructed. In the second step, using the rigid backbone and 8-nonen-1-ol as units, side-linked double bond sites were constructed. In the third step, ACR acrylate materials were grafted onto the backbone, and under organic solvent, additive, and initiator conditions, a conjugated intrinsically stretchable electroluminescent elastomer was prepared via free radical polymerization. The reaction equation is as follows:

[0023]

[0024] Specifically, the preparation method of the main chain conjugated intrinsic stretchable electroluminescent elastomer is carried out according to the following steps:

[0025] (1) under the condition of nitrogen protection, first, monomers and 4,7-dibromo-5-fluoro-2,1,3-benzothiadiazole monomers are dissolved in an organic solvent, an additive and an initiator are injected into a reaction container, and reaction is carried out at 95-105 DEG C for 3 days, after reaction is completed, cooling is carried out to room temperature, the reaction liquid is concentrated and dissolved in an organic good solvent, and a poor solvent is settled to obtain solid one. (2) solid one is dissolved in an organic solvent with 8-nonen-1-ol, an additive and an initiator are injected into the reaction container, and reaction is carried out at 110-130 DEG C for 12h; after reaction is completed, cooling is carried out to room temperature, the reaction liquid is concentrated and dissolved in an organic good solvent, and a poor solvent is settled to obtain solid two, finally, the solid two is dissolved in an organic good solvent with monomers corresponding to ACR acrylate side chains, and an initiator is added into the reaction container, and reaction is carried out at 65-75 DEG C for 24h.

[0026] (3) after reaction is completed and cooling is carried out to room temperature, the reaction liquid is concentrated and dissolved in an organic good solvent, and a poor solvent is settled, and column chromatography is purified, then, Soxhlet extraction is carried out with n-hexane, methanol and acetone, and extraction is carried out for 24-72h respectively, and a poor solvent is settled again, and after extraction, filtration and drying, the elastomer is obtained, which is the target product.

[0027] wherein, 1mmol monomers are dissolved in 10-30mL of an organic solvent, 0.1mmol of an additive and 0.1mmol of an initiator are added.

[0028] the organic solvent is selected from dioxane, toluene, chlorobenzene, DMF, chloroform, the additive is selected from tetrahydrofuran, TBAB, KOH, K2CO3, and the initiator includes azobisisobutyronitrile AIBN, azobisisoheptyl nitrile, tert-butyl hydroperoxide TBHP, benzoyl peroxide BPO, dodecanoyl peroxide DPO, tert-butyl peroxypivalate, diisopropyl peroxydicarbonate, potassium persulfate, cumene hydroperoxide CHP, cyclohexyl peroxydicarbonate, and palladium metal initiators such as tetraphenylphosphine palladium.

[0029] The application also provides application of the main chain conjugated intrinsic stretchable electroluminescent elastomer, and the elastomer can be applied to the flexible stretchable electronic field including flexible stretchable organic electroluminescent devices, electronic paper, soft robots, organic photovoltaics, flexible energy storage and artificial intelligence.

[0030] The application has the following beneficial effects:

[0031] 1. The patent application is a kind of main chain conjugated intrinsic stretchable electroluminescent elastomer as optoelectronic functional layer material applied in stretchable electroluminescent device.

[0032] 2. The organic electroluminescent unit is introduced into the traditional elastomer by chemical crosslinking method, the flexible acrylate side chain is first introduced into the rigid light-emitting conjugated main chain to form a rod-shaped bottle brush structure, which not only improves the intrinsic stretchability of the elastomer, but also has excellent luminescent properties and high carrier mobility, and solves the problem of intrinsic non-stretchability of traditional organic optoelectronic materials and the compatibility technical problem of the non-electroluminescent characteristics of traditional elastomers.

[0033] 3. The design strategy of the elastomer is unique, the structure is novel, and the elastomer has excellent thermal stability, luminescent properties, film forming property and high intrinsic stretchability, and is a kind of electroluminescent elastomer with important application potential.

[0034] 4. In addition, the elastomer is used as a light-emitting layer material, and the preparation of stretchable electroluminescent device with high stretchability, high stability and high efficiency is realized by solution processing method. BRIEF DESCRIPTION OF DRAWINGS

[0035] Figure 1 The thermal gravimetric curve of the elastomer in the embodiment of the application is shown in the figure.

[0036] Figure 2 The stretchable display diagram of the elastomer in the embodiment of the application is shown in the figure. DETAILED DESCRIPTION

[0037] The technical solutions of the present application will be further described in combination with the drawings and specific embodiments. It should be noted that the following embodiments are only part of the embodiments of the present application, but not limit the present application.

[0038] The present application relates to a kind of main chain conjugated intrinsic stretchable electroluminescent elastomer, the elastomer has the following structure general formula:

[0039]

[0040] Wherein m, n represents the number of repeat units of the component, Ar represents the conjugated structure, ACR represents acrylate side chain;

[0041] Ar represents the conjugated structure selected from one or several of the following molecular structures:

[0042]

[0043] Wherein R is C1-C 20 Straight-chain or branched alkyl or alkoxy chain, * is the connection point.

[0044] The monomer corresponding to the acrylate side chain represented by ACR has one of the following molecular structures:

[0045]

[0046] Where R' is C1-C 10 Straight-chain or branched alkyl groups.

[0047] The preparation method of this type of main-chain conjugated intrinsically stretchable electroluminescent elastomer is as follows: The first step is to use monomers... Using 4,7-dibromo-5-fluoro-2,1,3-benzothiadiazole as a starting material, a rigid backbone with a donor-acceptor structure was constructed. In the second step, side-linked double bond sites were constructed using the rigid backbone and 8-nonen-1-ol as units. In the third step, ACR acrylate materials were grafted onto the backbone. Under conditions of organic solvents, additives, and initiators, a conjugated intrinsically stretchable electroluminescent elastomer was prepared via free radical polymerization.

[0048] Example 1:

[0049] When Ar is Ar1 and ACR is ACR1, the preparation of elastomer ACR1-Ar1 is as follows: (where R is a C6 straight-chain alkyl group and R' is a C4 straight-chain alkyl group).

[0050]

[0051] Will 580 mg, 1 mmol, 4,7-dibromo-5-fluoro-2,1,3-benzothiadiazole (312 mg, 1 mmol), TBAB (32 mg, 0.1 mmol), and tetraphenylphosphine palladium (115 mg, 0.1 mmol) were placed in a 50 mL two-necked reaction flask and sealed. Nitrogen gas was purged three times. A 2 mol / L K₂CO₃ aqueous solution (7 mL) and toluene (21 mL) were added to the reaction flask, and the reaction was carried out at 95 °C for 3 days. After the reaction was completed, the mixture was cooled to room temperature, concentrated, and dissolved in the organic solvent dichloromethane. Methanol precipitated to obtain solid 1. This solid (508 mg, 1 mmol), 8-nonen-1-ol (768 mg, 6 mmol), and KOH (336 mg, 6 mmol) were placed in a 50 mL two-necked reaction flask and sealed. Nitrogen gas was purged three times. Chlorobenzene (20 mL) was added to the reaction flask, and the reaction was carried out at 130 °C for 12 h. After the reaction was completed, the mixture was cooled to room temperature, concentrated, and dissolved in the organic solvent dichloromethane. Methanol was used to precipitate solid 2. This solid was then reacted with dichloromethane (645 mg, 1 mmol) and ACR1 (3840 mg, 30 mmol) with azobisisobutyronitrile (67 mg, 1.5% mmol). 总The solution was placed in a 50 mL two-necked reaction flask and sealed. Nitrogen gas was purged three times. Tetrahydrofuran (10 mL) was then injected into the reaction flask, and the reaction was carried out at 65 °C for 24 h. After the reaction was completed and cooled to room temperature, the reaction solution was concentrated and dissolved in an organic solvent. Methanol was precipitated, purified by column chromatography, filtered, and dried to obtain the elastomer, which was the target product, with a yield of 82%.

[0052] Example 2:

[0053] When Ar is Ar2 and ACR is ACR2, the preparation of elastomer ACR1-Ar2 is as follows: (where R is a C6 straight-chain alkyl group and R' is a C8 straight-chain alkyl group):

[0054]

[0055] Will 587 mg, 1 mmol, 4,7-dibromo-5-fluoro-2,1,3-benzothiadiazole (312 mg, 1 mmol), TBAB (32 mg, 0.1 mmol), and tetraphenylphosphine palladium (115 mg, 0.1 mmol) were placed in a 50 mL two-necked reaction flask and sealed. Nitrogen gas was purged three times. A 2 mol / L K₂CO₃ aqueous solution (6 mL) and chloroform (20 mL) were added to the reaction flask, and the mixture was reacted at 105 °C for 3 days. After the reaction was completed, the mixture was cooled to room temperature, concentrated, dissolved in the organic solvent chloroform, and precipitated with ethanol to obtain solid 1. This solid (515 mg, 1 mmol), 8-nonen-1-ol (768 mg, 6 mmol), and KOH (336 mg, 6 mmol) were placed in a 50 mL two-necked reaction flask and sealed. Nitrogen gas was purged three times. Toluene (20 mL) was added to the reaction flask, and the reaction was carried out at 110 °C for 12 h. After the reaction was completed, the mixture was cooled to room temperature, concentrated, dissolved in the organic solvent chloroform, and precipitated with ethanol to obtain solid 2. This solid 2 (652 mg, 1 mmol), ACR1 (5529 mg, 30 mmol), and azobisisobutyronitrile (93 mg, 1.5% mmol) were then reacted. 总 The solution was placed in a 50 mL two-necked reaction flask and sealed. Nitrogen gas was purged three times. Tetrahydrofuran (20 mL) was then injected into the reaction flask, and the reaction was carried out at 75 °C for 24 h. After the reaction was completed and cooled to room temperature, the reaction solution was concentrated and dissolved in an organic solvent. Methanol was precipitated, purified by column chromatography, filtered, and dried to obtain the elastomer, which was the target product, with a yield of 73%.

[0056] Example 3:

[0057] When Ar is Ar3 and ACR is ACR2, the preparation of elastomer ACS1-Ar3 is as follows: (where R is a C6 straight-chain alkyl group and R' is a C4 straight-chain alkyl group):

[0058]

[0059] Will 640 mg, 1 mmol; 4,7-dibromo-5-fluoro-2,1,3-benzothiadiazole (312 mg, 1 mmol); TBAB (32 mg, 0.1 mmol); tetraphenylphosphine palladium (115 mg, 0.1 mmol) were placed in a 50 mL two-necked reaction flask and sealed. Nitrogen gas was purged three times. A 2 mol / L K₂CO₃ aqueous solution (5 mL) and chlorobenzene (15 mL) were added to the reaction flask, and the mixture was reacted at 95 °C for 3 days. After the reaction was completed, the mixture was cooled to room temperature, concentrated, and dissolved in the organic solvent dichloromethane. Methanol precipitated to obtain solid 1. This solid (568 mg, 1 mmol), 8-nonen-1-ol (768 mg, 6 mmol), and KOH (336 mg, 6 mmol) were placed in a 50 mL two-necked reaction flask and sealed. Nitrogen gas was purged three times. Dioxane (20 mL) was injected into the reaction flask, and the reaction was carried out at 130 °C for 12 h. After the reaction was completed, the mixture was cooled to room temperature, concentrated, and dissolved in the organic solvent dichloromethane. Methanol was used to precipitate solid 2. This solid 2 (705 mg, 1 mmol), ACR2 (4266 mg, 30 mmol), and benzoyl peroxide (74 mg, 1.5% mmol) were then reacted. 总 The solution was placed in a 50 mL two-necked reaction flask and sealed. Nitrogen gas was purged three times. 10 mL of chloroform was then injected into the reaction flask, and the mixture was reacted at 65 °C for 24 h. After the reaction was completed and cooled to room temperature, the reaction solution was concentrated and dissolved in an organic solvent. Methanol was precipitated, purified by column chromatography, filtered, and dried to obtain the elastomer, which was the target product, with a yield of 77%.

[0060] Example 4:

[0061] When Ar is Ar4 and ACR is ACR2, the preparation of the elastomer ACR2-Ar4 is as follows: (where R is a C6 straight-chain alkyl group and R' is a C6 straight-chain alkyl group):

[0062]

[0063] Will (628mg, 1mmol), 4,7-dibromo-5-fluoro-2,1,3-benzothiadiazole (312mg, 1mmol), TBAB (32mg, 0.1mmol), tetrakis triphenylphosphine palladium (115mg, 0.1mmol) were put into a 50mL two-necked flask and sealed, and the nitrogen was exchanged for three times. The reaction flask was injected with 2mol / L K2CO3 aqueous solution (10mL), dioxane (30mL), and reacted at 95°C for 3 days. After the reaction was completed, it was cooled to room temperature, and the reaction liquid was concentrated and dissolved with an organic solvent dichloromethane, and then precipitated with methanol to obtain solid 1; solid 1 (556mg, 1mmol), 8-nonen-1-ol (768mg, 6mmol) and KOH (336mg, 6mmol) were put into a 50mL two-necked flask and sealed, and the nitrogen was exchanged for three times. The reaction flask was injected with DMF (20mL), and reacted at 130°C for 12h; after the reaction was completed, it was cooled to room temperature, and the reaction liquid was concentrated and dissolved with an organic solvent dichloromethane, and then precipitated with methanol to obtain solid 2; solid 2 (693mg, 1mmol), ACR2 (5106mg, 30mmol) and tert-butyl hydroperoxide (87mg, 1.5% m 总 ) were put into a 50mL two-necked flask and sealed, and the nitrogen was exchanged for three times. The reaction flask was injected with toluene (10mL), and reacted at 65°C for 24h. After the reaction was completed and cooled to room temperature, the reaction liquid was concentrated and dissolved with an organic solvent, precipitated with methanol, and column chromatography was performed, and then the product was obtained by filtration and drying, and the yield was 77%.

[0064] Example 5:

[0065] When Ar is Ar5 and ACR is ACR3, the preparation of elastomer ACR3-Ar5 is as follows (wherein R is a straight-chain alkyl group of C6, and R' is a straight-chain alkyl group of C2):

[0066]

[0067] The (420mg, 1mmol), 4,7-dibromo-5-fluoro-2,1,3-benzothiadiazole (312mg, 1mmol), TBAB (32mg, 0.1mmol), tetrakis triphenylphosphine palladium (115mg, 0.1mmol) were put into a 50mL two-necked flask and sealed, and the nitrogen was exchanged for three times. The reaction flask was injected with 2mol / L K2CO3 aqueous solution (4mL), chloroform (15mL), and reacted at 95°C for 3 days. After the reaction was completed, it was cooled to room temperature, and the reaction liquid was concentrated and dissolved with organic solvent dichloromethane, and then precipitated with methanol to obtain solid 1; solid 1 (348mg, 1mmol), 8-nonen-1-ol (768mg, 6mmol) and KOH (336mg, 6mmol) were put into a 50mL two-necked flask and sealed, and the nitrogen was exchanged for three times. The reaction flask was injected with toluene (20mL), and reacted at 130°C for 12h; after the reaction was completed, it was cooled to room temperature, and the reaction liquid was concentrated and dissolved with organic solvent dichloromethane, and then precipitated with methanol to obtain solid 2; solid 2 (485mg, 1mmol), ACR3 (3483mg, 30mmol) and diisopropylbenzene hydroperoxide (60mg, 1.5% m 总 ) were put into a 50mL two-necked flask and sealed, and the nitrogen was exchanged for three times. The reaction flask was injected with DMF (10mL), and reacted at 65°C for 24h. After the reaction was completed and cooled to room temperature, the reaction liquid was concentrated and dissolved with organic solvent, precipitated with methanol, and then column chromatography, filtration and drying to obtain the elastomer, which was the target product, with a yield of 80%.

[0068] Example 6:

[0069] When Ar is Ar6 and ACR is ACR3, the preparation of elastomer ACR3-Ar6 is as follows (wherein R is a straight-chain alkyl group of C6, and R' is a straight-chain alkyl group of C3):

[0070]

[0071] When Ar is Ar6 and ACR is ACR3, the preparation of elastomer ACR3-Ar6 is as follows (wherein R is a straight-chain alkyl group of C6, and R' is a straight-chain alkyl group of C3): (500 mg, 1 mmol), 4,7-dibromo-5-fluoro-2,1,3-benzothiadiazole (312 mg, 1 mmol), TBAB (32 mg, 0.1 mmol), tetrakis triphenylphosphine palladium (115 mg, 0.1 mmol) were put into a 50 mL two-necked flask and sealed, and the nitrogen was exchanged for three times. A 2 mol / L aqueous solution of K2CO3 (6 mL) and DMF (24 mL) were injected into the flask, and the reaction was carried out at 95°C for 3 days. After the reaction was completed, the reaction solution was cooled to room temperature, concentrated, dissolved in dichloromethane, and precipitated in methanol to obtain solid 1; 1 (428 mg, 1 mmol), 8-nonen-1-ol (768 mg, 6 mmol), and KOH (336 mg, 6 mmol) were put into a 50 mL two-necked flask and sealed, and the nitrogen was exchanged for three times. Toluene (20 mL) was injected into the flask, and the reaction was carried out at 130°C for 12 h; after the reaction was completed, the reaction solution was cooled to room temperature, concentrated, dissolved in dichloromethane, and precipitated in methanol to obtain solid 2; 2 (565 mg, 1 mmol), ACR3 (3603 mg, 30 mmol), and azobisisobutyronitrile (62 mg, 1.5% m 总 ) were put into a 50 mL two-necked flask and sealed, and the nitrogen was exchanged for three times. Tetrahydrofuran (10 mL) was injected into the flask, and the reaction was carried out at 65°C for 24 h. After the reaction was completed and the reaction solution was cooled to room temperature, it was concentrated and dissolved in an organic solvent, precipitated in methanol, and column chromatography was performed, and the elastomer obtained after filtration and drying was the target product, with a yield of 88%.

[0072] Example 7:

[0073] When Ar is Ar7 and ACR is ACR4, the preparation of elastomer ACR4-Ar7 is as follows (wherein R is a straight-chain alkyl group of C6, and R' is a straight-chain alkyl group of C2):

[0074]

[0075] ​(600 mg, 1 mmol), 4,7-dibromo-5-fluoro-2,1,3-benzothiadiazole (312 mg, 1 mmol), TBAB (32 mg, 0.1 mmol), tetrakis triphenylphosphine palladium (115 mg, 0.1 mmol) were put into a 50 mL two-necked flask and sealed, and the nitrogen was exchanged for three times. A 2 mol / L aqueous solution of K2CO3 (7 mL) and chloroform (21 mL) were injected into the flask, and the reaction was carried out at 95°C for 3 days. After the reaction was completed, the reaction solution was cooled to room temperature, concentrated, dissolved in dichloromethane, and precipitated in methanol to obtain solid 1; 1 (528 mg, 1 mmol), 8-nonen-1-ol (768 mg, 6 mmol), and KOH (336 mg, 6 mmol) were put into a 50 mL two-necked flask and sealed, and the nitrogen was exchanged for three times. Chlorobenzene (20 mL) was injected into the flask, and the reaction was carried out at 130°C for 12 h; after the reaction was completed, the reaction solution was cooled to room temperature, concentrated, dissolved in dichloromethane, and precipitated in methanol to obtain solid 2; 2 (665 mg, 1 mmol), ACR4 (4716 mg, 30 mmol), and di-t-butyl peroxide (81 mg, 1.5% m 总 ) were put into a 50 mL two-necked flask and sealed, and the nitrogen was exchanged for three times. Dioxane (10 mL) was injected into the flask, and the reaction was carried out at 65°C for 24 h. After the reaction was completed and the reaction solution was cooled to room temperature, it was concentrated and dissolved in an organic solvent, precipitated in methanol, and column chromatography was performed, and the elastomer obtained after filtration and drying was the target product, with a yield of 83%.

[0076] Example 8:

[0077] When Ar is Ar8 and ACR is ACR5, the preparation of elastomer ACR5-Ar8 is as follows (wherein R is a straight-chain alkyl group with C6, and R' is a straight-chain alkyl group with C3):

[0078]

[0079] When Ar is Ar8 and ACR is ACR5, the preparation of elastomer ACR5-Ar8 is as follows (wherein R is a straight-chain alkyl group with C6, and R' is a straight-chain alkyl group with C3): (854mg, 1mmol), 4,7-dibromo-5-fluoro-2,1,3-benzothiadiazole (312mg, 1mmol), TBAB (32mg, 0.1mmol), tetrakis triphenylphosphine palladium (115mg, 0.1mmol) were put into a 50mL two-necked flask and sealed, and the nitrogen was exchanged for three times. The reaction flask was injected with 2mol / L K2CO3 aqueous solution (10mL), chlorobenzene (30mL), and reacted at 95°C for 3 days. After the reaction was completed, it was cooled to room temperature, concentrated, dissolved in dichloromethane, and precipitated in methanol to obtain solid 1; 782mg (1mmol) of solid 1, 8-nonen-1-ol (768mg, 6mmol), and KOH (336mg, 6mmol) were put into a 50mL two-necked flask and sealed, and the nitrogen was exchanged for three times. The reaction flask was injected with dioxane (20mL), and reacted at 130°C for 12h; after the reaction was completed, it was cooled to room temperature, concentrated, dissolved in dichloromethane, and precipitated in methanol to obtain solid 2; 919mg (1mmol) of solid 2, ACR5 (3453mg, 30mmol), and dibenzoyl peroxide (66mg, 1.5% m 总 ) were put into a 50mL two-necked flask and sealed, and the nitrogen was exchanged for three times. The reaction flask was injected with DMF (10mL), and reacted at 65°C for 24h. After the reaction was completed and cooled to room temperature, the reaction liquid was concentrated and dissolved in an organic solvent, precipitated in methanol, and column chromatography was performed to obtain the elastomer, which was the target product, with a yield of 89%.

[0080] Example 9:

[0081] When Ar is Ar9 and ACR is ACR6, the preparation of elastomer ACR6-Ar9 is as follows (wherein R is a straight-chain alkyl group of C6, and R' is a straight-chain alkyl group of C2):

[0082]

[0083] ​(608 mg, 1 mmol), 4,7-dibromo-5-fluoro-2,1,3-benzothiadiazole (312 mg, 1 mmol), TBAB (32 mg, 0.1 mmol), tetrakis triphenylphosphine palladium (115 mg, 0.1 mmol) were put into a 50 mL two-necked flask and sealed, and the nitrogen was exchanged for three times. A 2 mol / L aqueous solution of K2CO3 (7 mL) and toluene (21 mL) were injected into the flask, and the reaction was carried out at 95°C for 3 days. After the reaction was completed, the reaction solution was cooled to room temperature, concentrated, dissolved in dichloromethane, and precipitated in methanol to obtain solid 1; 1 (536 mg, 1 mmol), 8-nonen-1-ol (768 mg, 6 mmol), and KOH (336 mg, 6 mmol) were put into a 50 mL two-necked flask and sealed, and the nitrogen was exchanged for three times. Chlorobenzene (20 mL) was injected into the flask, and the reaction was carried out at 130°C for 12 h; after the reaction was completed, the reaction solution was cooled to room temperature, concentrated, dissolved in dichloromethane, and precipitated in methanol to obtain solid 2; 2 (673 mg, 1 mmol), ACR6 (5286 mg, 30 mmol), and azobisisobutyronitrile (89 mg, 1.5% m 总 ) were put into a 50 mL two-necked flask and sealed, and the nitrogen was exchanged for three times. Tetrahydrofuran (10 mL) was injected into the flask, and the reaction was carried out at 65°C for 24 h. After the reaction was completed and the reaction solution was cooled to room temperature, it was concentrated and dissolved in an organic solvent, precipitated in methanol, and column chromatography was performed, and the elastomer obtained after filtration and drying was the target product, with a yield of 78%.

[0084] Example 10:

[0085] When Ar is Ar10 and ACR is ACR6, the preparation of elastomer ACR6-Ar10 is as follows (wherein R is a straight-chain alkyl group of C6, and R' is a straight-chain alkyl group of C3):

[0086]

[0087] When Ar is Ar10 and ACR is ACR6, the preparation of elastomer ACR6-Ar10 is as follows (wherein R is a straight-chain alkyl group of C6, and R' is a straight-chain alkyl group of C3): (968mg, 1mmol), 4,7-dibromo-5-fluoro-2,1,3-benzothiadiazole (312mg, 1mmol), TBAB (32mg, 0.1mmol), tetrakis triphenylphosphine palladium (115mg, 0.1mmol) were put into a 50ml two-necked flask and sealed, and the flask was replaced with nitrogen for three times. Concentrated K2CO3 aqueous solution (10ml) with a concentration of 2mol / L, DMF (30ml) were injected into the flask, and the reaction was carried out at 95°C for 3 days. After the reaction was completed, the reaction solution was cooled to room temperature, concentrated, dissolved in dichloromethane, and precipitated in methanol to obtain solid 1; solid 1 (896mg, 1mmol), 8-nonen-1-ol (768mg, 6mmol) and KOH (336mg, 6mmol) were put into a 50ml two-necked flask and sealed, and the flask was replaced with nitrogen for three times. Tetrahydrofuran (10ml) was injected into the flask, and the reaction was carried out at 130°C for 12h; after the reaction was completed, the reaction solution was cooled to room temperature, concentrated, dissolved in dichloromethane, and precipitated in methanol to obtain solid 2; solid 2 (1033mg, 1mmol), ACR6 (5706mg, 30mmol) and tert-butyl hydroperoxide (101mg, 1.5% m 总 ) were put into a 50ml two-necked flask and sealed, and the flask was replaced with nitrogen for three times. Tetrahydrofuran (10ml) was injected into the flask, and the reaction was carried out at 65°C for 24h. After the reaction was completed and the reaction solution was cooled to room temperature, it was concentrated and dissolved in an organic solvent, precipitated in methanol, and column chromatography was used for purification, and then the product was obtained by filtration and drying. The yield was 76%.

[0088] Example 11: Preparation of OLED device

[0089] ITO glass was cleaned by ultrasonic cleaning and treated with oxygen plasma, and the sheet resistance of the ITO glass was 10Ω / cm 2 . The hole injection layer was PEDOT or PVK, and the light-emitting layer used any one of ACR1-Ar1, ACR1-Ar2, ACR2-Ar3, ACR2-Ar4, ACR3-Ar5, ACR3-Ar6, ACR4-Ar7, ACR5-Ar8, ACR6-Ar9, and ACR6-Ar10. The hole injection layer and the light-emitting layer were both prepared by spin coating. The cathode electrode was Ca / Al or LiF / Al. Table 1 shows the electroluminescent properties of the above OLED device, wherein the maximum luminance of the OLED device prepared based on ACR6-Ar10 was 13274cd / m 2 ; the tensile strain of ACR1-Ar2 could reach 500%.

[0090] Table 1: Electroluminescent properties of OLED device

[0091]

[0092] The above are the embodiments of the present application. It should be noted that the present application is not limited to these examples, and these examples are only for better understanding of the present application. Any equivalent transformation made according to the technical solutions of the present application also belongs to the protection scope of the present application.

Claims

1. A method of making a main-chain conjugated intrinsically stretchable electroluminescent elastomer, characterized in that, The preparation method comprises the following steps: a first step of preparing monomers 4,7-dibromo-5-fluoro-2,1,3-benzothiadiazole as a raw material, a rigid main chain of the acceptor structure is constructed; a second step of constructing a side chain branched double bond site with 8-nonen-1-ol as a unit; a third step of grafting an acrylic ester material corresponding to the monomer of ACR with the main chain, under the conditions of an organic solvent, an additive and an initiator, a main chain conjugated intrinsic stretchable electroluminescent elastomer is prepared by a free radical polymerization mode, and a reaction equation is as follows: Wherein m represents the number of repeating units of the component, Ar represents a conjugated structure; wherein the conjugated structure represented by Ar is selected from one or more of the following molecular structures: wherein R is a linear or branched alkyl or alkoxy chain of 1 to 6 carbon atoms, and * is the point of attachment. 20 wherein R is a linear or branched alkyl or alkoxy chain of 1 to 6 carbon atoms, and * is the point of attachment Wherein the monomer corresponding to ACR is one of the following molecular structures: wherein R' is a linear or branched alkyl chain of C1-C 10 4 carbon atoms.

2. The method for preparing a main-chain conjugated intrinsically stretchable electroluminescent elastomer according to claim 1, characterized in that, The first step includes the following: (1) under nitrogen protection, monomers 4,7-dibromo-5-fluoro-2,1,3-benzothiadiazole is dissolved in an organic solvent, an additive and an initiator are added, and the reaction is carried out at 95-105°C; (2) After the reaction is completed, cool to room temperature, concentrate the reaction solution, then dissolve it in a good organic solvent, and precipitate the solid in a poor solvent; The second step includes the following: (3) Dissolve the solid obtained in (2) and 8-nonen-1-ol in an organic solvent, add an additive and an initiator, and react at 110-130°C; (4) After the reaction is completed, cool to room temperature, concentrate the reaction solution, then dissolve it in a good organic solvent, and precipitate the solid in a poor solvent; The third step includes the following: (5) Dissolve the solid obtained in (4) and the monomer corresponding to ACR in an organic solvent, add an additive and an initiator, and react at 65-75°C; (6) After the reaction is completed, extract, precipitate, filter, and dry to obtain the elastomer, which is the target product, main chain conjugated intrinsic stretchable electroluminescent elastomer.

3. The method for preparing a main-chain conjugated intrinsically stretchable electroluminescent elastomer according to claim 1, characterized in that, In the first step, 1 mmol The monomer is dissolved in 10-30 mL of organic solvent, 0.1 mmol of additive is added, and 0.1 mmol of initiator.

4. A main chain conjugated intrinsic stretchable electroluminescent elastomer prepared by the method of any one of claims 1-3.

5. Use of a main-chain conjugated intrinsically stretchable electroluminescent elastomer prepared according to the process of any one of claims 1 to 3, characterized in that, The elastomer is applied to the field of flexible and stretchable electronics, including flexible and stretchable organic electroluminescent devices, electronic paper, soft robots, organic photovoltaics, flexible energy storage, and artificial intelligence.

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