Main chain conjugated intrinsic stretchable electroluminescent elastomer as well as preparation and application thereof

Abstract

The invention belongs to the technical field of photoelectric materials and application, and discloses a main chain conjugated intrinsic stretchable electroluminescent elastomer as well as preparation and application thereof. The elastomer is prepared by taking a conjugated structure with excellent photoelectric properties as a rigid main chain and polyacrylate as a flexible side chain through free radical polymerization reaction. The innovation of the invention lies in that a flexible acrylate side chain is introduced into a rigid luminous conjugated main chain for the first time in a chemical cross-linking manner to form a rod-like bottle brush structure, so that the elastomer has excellent photoelectric characteristics on the basis of improving the intrinsic tensile property of the elastomer; the structure is novel, the design strategy is unique, and meanwhile the problems that a traditional conjugated luminescent material is not intrinsic in stretchability and a traditional elastomer does not have the high-performance photoelectric characteristic are solved; the elastomer is used as a luminescent layer material to prepare an organic photoelectric device with high stability, high stretchability and high efficiency.

Description

Technical Field

[0001] The invention belongs to the field of optoelectronic materials and application technology, and specifically relates to the design, synthesis and application of a main chain conjugated intrinsically stretchable electroluminescent elastomer. Background Art

[0002] Flexible and stretchable electronics have a wide range of applications, especially for wearable and implantable devices, so it has attracted increasing attention from academia and industry. In recent years, flexible and stretchable electronics with high elasticity and ductility have been rapidly developed and significantly improved our daily lives, indirectly leading to a shift in research in academia and industry to wearable electronics, medical monitoring devices and electronic skin. For these applications, high-performance flexible and stretchable light-emitting polymer semiconductor materials that can adapt to mechanical deformation are required to conform to the soft, dynamic and curvilinear human body. Compared with traditional inorganic materials, organic electroluminescent materials can be prepared by solution method to produce flexible, large-area and patterned organic optoelectronic devices, which greatly meet 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, structural adjustability and potential application in various optoelectronic devices. Conjugated polymers can be used to manufacture electronic devices with light weight, 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 OLED in 1987, the continuous improvement and innovation of the light-emitting functional layer has led to the rapid development of its technology. In 1992, researchers reported the first bendable flexible OLED by using poly (1,4-phenylene-vinylene) as the light-emitting layer, but due to the limitation of the exciton spin-orbit theory, the external quantum efficiency was only about 1%. Historically, 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 current great demand for OLED commercialization, the development of flexible and stretchable OLEDs has great potential. In order to make OLED devices maintain good performance during stretching, in addition to optimizing the device structure and preparation process, it is of great significance to design and synthesize intrinsically stretchable electroluminescent materials to prepare stretchable optoelectronic devices.

[0004] Polymer semiconductors have emerged as an important candidate 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 often suffer from poor flexibility, which results in film breakage during stretching, thereby compromising the optoelectronic performance of the device. Research on intrinsically stretchable polymer semiconductors focuses on the structure-property relationship between molecular design and film properties. A general strategy to improve the stretchability of polymer semiconductor materials is to optimize the film microstructure through molecular engineering, in which a balanced distribution of crystalline and amorphous regions is important. The introduction of appropriate CBs on the polymer backbone can achieve such a film microstructure, imparting stretchability through an energy dissipation mechanism and self-healing properties through hydrogen-bonded CBs. So far, polymer films have been cracked at solidification strains exceeding ε = 100% while maintaining carrier mobilities at 1 cm 2 V -1 s -1 The above is achieved by incorporating hydrogen-bonded PDCA CBs in DPP-based DA polymers, which effectively improves carrier transport and mechanical compliance, and can also tune the interchain interactions of semiconducting polymers by changing the side chains.

[0005] Precise morphological 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 fibers and interwoven high Mn linker chains between the deformable amorphous regions is an important factor for efficient charge transport. The morphology of the films can be altered by tuning the regioregularity of Mn and polymer properties as well as by structural modifications of the polymer backbone and side chains. With the development of synthetic chemistry and processing technology, fine control of these parameters will facilitate the realization of practical devices.

[0006] In order to obtain stretchable CPs films without sacrificing optoelectronic properties, rational polymer design through backbone and side chain engineering is usually the preferred approach. Müller et al. demonstrated [1] , semiconducting diblock copolymers of polyethylene (PE) and regioregular poly(3-hexylthiophene) (P3HT) exhibited excellent flexibility with an elongation at break exceeding 600% and a tensile modulus of approximately 70 MPa, opening the way for the development of intrinsically stretchable CPs. Since then, copolymerization with “flexible linkers” containing aliphatic chains has been used to optimize film morphology and reduce the melting temperature of CPs. Regarding side-chain engineering, researchers have thoroughly studied the role of side-chain architecture in controlling polymer chain interactions and solution processability. Shinohara et al. [2]By using flexible branched alkyl chains as “internal plasticizers”, a viscoelastic CPs variant was developed, and the viscous CPs with an alkyl / alkyl ratio of 68:32 could be extended 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 elastic polymers is also a feasible strategy. Xu et al. demonstrated [3] After blending DPPT-TT with a commonly used elastomer (SEBS), the elastic modulus of the constrained film decreased dramatically and could be stretched up to 100% without reducing the charge carrier mobility. It is well known that blending with elastomers can make the film stretchable, but avoiding phase separation between the semiconducting polymer and the inert polymer matrix while achieving a balance between electroluminescent performance and mechanical properties remains a difficult task.

[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,FJStadler,L.Wang,T.

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

[0011] [3]Xu J, Wang S, Wang GJ, et al. Highly stretchable polymersemiconductor films through thenanoconfinement effect. Science 2017; 355:59–64. Summary of the invention

[0012] In view of the above technical problems in the prior art, the present invention discloses a method for preparing a main chain conjugated intrinsic stretchable electroluminescent elastomer and an application method thereof as a light-emitting layer material in an organic electroluminescent device. This type of elastomer is prepared by free radical polymerization reaction with a conjugated structure with excellent photoelectric properties as a rigid main chain and polyacrylate as a flexible side chain. The elastomer is used to prepare the light-emitting layer of an intrinsically stretchable electroluminescent device, and realizes the preparation of a highly stretchable and highly stable stretchable optoelectronic device, which provides a new technical solution for how to realize the electroluminescence of traditional elastomers and how to solve the problem of the intrinsic non-stretchability of traditional conjugated fluorescent materials.

[0013] The technical solution adopted by the present invention is as follows:

[0014] The present invention provides a main chain conjugated intrinsic stretchable electroluminescent elastomer, which has the following general structural formula:

[0015]

[0016] Wherein, 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 A straight or branched alkyl or alkoxy chain, * is the point of attachment.

[0020] In a further technical solution, the acrylic acid ester side chain represented by ACR is one of the following molecular structures:

[0021] Where R' is C1-C 10 A straight chain or branched chain alkyl group.

[0022] The present invention also provides a method for preparing the main chain conjugated intrinsic stretchable electroluminescent elastomer, the preparation method comprising: a first step of using a monomer 4,7-Dibromo-5-fluoro-2,1,3-benzothiadiazole is used as a raw material to construct a rigid main chain of a donor-acceptor structure; the second step is to use the rigid main chain and 8-nonen-1-ol as units to construct a side chain grafting double bond site; the third step is to graft the ACR acrylate material with the main chain, and prepare the main chain conjugated intrinsic stretchable electroluminescent elastomer by free radical polymerization under the conditions of organic solvent, additive and initiator. The reaction equation is as follows:

[0023]

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

[0025] (1) Under nitrogen protection, first The monomer and 4,7-dibromo-5-fluoro-2,1,3-benzothiadiazole monomer are dissolved in an organic solvent, and additives and initiators are respectively injected into a reaction container, and the reaction is carried out at 95-105°C for 3 days. After the reaction is completed, the reaction solution is cooled to room temperature, and the reaction solution is concentrated and dissolved in an organic good solvent. The poor solvent is precipitated to obtain solid 1. (2) Solid 1 and 8-nonene-1-ol are dissolved in an organic solvent and added to a reaction container, and additives and initiators are injected into the reaction container at 110-130°C for 12 hours. After the reaction is completed, the reaction solution is cooled to room temperature, and the reaction solution is concentrated and dissolved in an organic good solvent. The poor solvent is precipitated to obtain solid 2. Finally, the monomer corresponding to the ACR acrylic ester side chain is dissolved in an organic good solvent and added together, and the initiator is added to the reaction container, and the reaction is carried out at 65-75°C for 24 hours.

[0026] (3) After the reaction is completed and cooled to room temperature, the reaction solution is concentrated and dissolved with an organic good solvent, precipitated with a poor solvent, and purified by column chromatography. Then, Soxhlet extraction is performed with n-hexane, methanol, and acetone solvents for 24-72 hours respectively. Precipitated with a poor solvent again, filtered, and dried to obtain an elastomer, which is the target product.

[0027] Among them, 1mmol The monomer is dissolved in 10-30 mL of an organic solvent, and 0.1 mmol of an additive and 0.1 mmol of an initiator are added.

[0028] The organic solvent is selected from dioxane, toluene, chlorobenzene, DMF, and chloroform; the additive is selected from tetrahydrofuran, TBAB, KOH, and K2CO3; the initiator includes azobisisobutyronitrile AIBN, azobisisoheptanenitrile, tert-butyl peroxide TBHP, dibenzoyl peroxide BPO, dodecanoyl peroxide DPO, tert-butyl peroxypivalate, diisopropyl peroxydicarbonate, potassium persulfate, isopropylbenzene hydroperoxide CHP, cyclohexyl peroxydicarbonate, tetrakistriphenylphosphine palladium and other palladium-based metal initiators.

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

[0030] The present invention has the following beneficial effects:

[0031] 1. This patent invents a main chain conjugated intrinsic stretchable electroluminescent elastomer as a photoelectric functional layer material for use in stretchable electroluminescent devices.

[0032] 2. The organic electroluminescent unit is introduced into the traditional elastomer by chemical cross-linking, and the flexible acrylate side chain is introduced into the rigid luminescent conjugated main chain for the first time to form a rod-like bottle brush structure. This not only improves the intrinsic stretchability of the elastomer, but also has excellent luminescence properties and high carrier mobility. At the same time, it solves the intrinsic non-stretchability problem of traditional organic optoelectronic materials and the compatibility technical problem of electroluminescent properties that traditional elastomers do not have.

[0033] 3. This type of elastomer has a unique design strategy and novel structure. It has excellent thermal stability, luminescence properties, film-forming properties and high intrinsic stretchability. It is a type of electroluminescent elastomer with important application potential.

[0034] 4. In addition, by using elastomer as the light-emitting layer material and solution processing, the preparation of stretchable electroluminescent devices with high stretchability, high stability and high efficiency was achieved. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Figure 1 is a thermal weight loss curve of the elastomer in an embodiment of the present invention;

[0036] Figure 2 This is a diagram showing the stretching of the elastomer in an embodiment of the present invention. DETAILED DESCRIPTION

[0037] The technical solution of the present invention is further described below in conjunction with the accompanying drawings and specific embodiments. It should be noted that the following embodiments are only partial embodiments of the present invention, and are not intended to limit the present invention.

[0038] The present invention relates to a main chain conjugated intrinsic stretchable electroluminescent elastomer, which has the following general structural formula:

[0039]

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

[0041] The conjugated structure represented by Ar is selected from one or more of the following molecular structures:

[0042]

[0043] Where R is C1-C 20 A straight or branched alkyl or alkoxy chain, * is the point of attachment.

[0044] The monomer corresponding to the acrylic ester side chain represented by ACR is one of the following molecular structures:

[0045]

[0046] Where R' is C1-C 10 A straight chain or branched chain alkyl group.

[0047] The preparation method of this type of main chain conjugated intrinsic stretchable electroluminescent elastomer is as follows: the first step is to use monomers 4,7-dibromo-5-fluoro-2,1,3-benzothiadiazole is used as the raw material to construct a rigid main chain of the donor-acceptor structure. The second step is to use the rigid main chain and 8-nonen-1-ol as units to construct the side chain grafting double bond site. The third step is to graft the ACR acrylate material with the main chain. Under the conditions of organic solvent, additives and initiator, the main chain conjugated intrinsic stretchable electroluminescent elastomer is prepared by free radical polymerization.

[0048] Embodiment 1:

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

[0050]

[0051] Will (580mg, 1mmol), 4,7-dibromo-5-fluoro-2,1,3-benzothiadiazole (312mg, 1mmol), TBAB (32mg, 0.1mmol), tetrakistriphenylphosphine palladium (115mg, 0.1mmol) were placed in a 50mL two-mouth reaction bottle and sealed, and nitrogen was replaced three times. A 2mol / L K2CO3 aqueous solution (7mL) and toluene (21mL) were injected into the reaction bottle and reacted at 95°C for 3 days. After the reaction was completed, it was cooled to room temperature, the reaction solution was concentrated and dissolved with an organic solvent of dichloromethane, and methanol was precipitated to obtain solid 1; it (508mg, 1mmol), 8-nonene-1-ol (768mg, 6mmol) and KOH (336mg, 6mmol) were placed in a 50mL two-mouth reaction bottle and sealed, and nitrogen was replaced three times. Chlorobenzene (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, the reaction solution was concentrated and dissolved in an organic solvent, dichloromethane, and methanol was precipitated to obtain solid 2, which (645 mg, 1 mmol), ACR1 (3840 mg, 30 mmol) and azobisisobutyronitrile (67 mg, 1.5% m 总) was placed in a 50 mL two-necked reaction bottle and sealed, and nitrogen was replaced three times. Tetrahydrofuran (10 mL) was injected into the reaction bottle and reacted at 65 ° C for 24 h. After the reaction was completed and cooled to room temperature, the reaction solution was concentrated and dissolved with an organic solvent, precipitated with methanol, purified by column chromatography, filtered and dried to obtain an elastomer as the target product with a yield of 82%.

[0052] Embodiment 2:

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

[0054]

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

[0056] Embodiment 3:

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

[0058]

[0059] Will (640mg, 1mmol), 4,7-dibromo-5-fluoro-2,1,3-benzothiadiazole (312mg, 1mmol), TBAB (32mg, 0.1mmol), tetrakistriphenylphosphine palladium (115mg, 0.1mmol) were placed in a 50mL two-mouth reaction bottle and sealed, and nitrogen was replaced three times. A 2mol / L K2CO3 aqueous solution (5mL) and chlorobenzene (15mL) were injected into the reaction bottle and reacted at 95°C for 3 days. After the reaction was completed, it was cooled to room temperature, the reaction solution was concentrated and dissolved with an organic solvent of dichloromethane, and methanol was precipitated to obtain solid 1; it (568mg, 1mmol), 8-nonene-1-ol (768mg, 6mmol) and KOH (336mg, 6mmol) were placed in a 50mL two-mouth reaction bottle and sealed, and nitrogen was replaced 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, the reaction solution was concentrated and dissolved in an organic solvent, dichloromethane, and methanol was precipitated to obtain solid 2, which (705 mg, 1 mmol), ACR2 (4266 mg, 30 mmol) and dibenzoyl peroxide (74 mg, 1.5% m 总 ) was placed in a 50 mL two-necked reaction bottle and sealed, and nitrogen was replaced three times. Chloroform (10 mL) was injected into the reaction bottle and reacted at 65°C for 24 h. After the reaction was completed and cooled to room temperature, the reaction solution was concentrated and dissolved with an organic solvent, precipitated with methanol, purified by column chromatography, filtered and dried to obtain an elastomer as the target product with a yield of 77%.

[0060] Embodiment 4:

[0061] When Ar is selected as Ar4 and ACR is selected as ACR2, the preparation of elastomer ACR2-Ar4 is as follows: (wherein 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), tetrakistriphenylphosphine palladium (115mg, 0.1mmol) were placed in a 50mL two-mouth reaction bottle and sealed, and nitrogen was replaced three times. A 2mol / L K2CO3 aqueous solution (10mL) and dioxane (30mL) were injected into the reaction bottle and reacted at 95°C for 3 days. After the reaction was completed, it was cooled to room temperature, the reaction solution was concentrated and dissolved with an organic solvent dichloromethane, and methanol was precipitated to obtain solid 1; it (556mg, 1mmol), 8-nonene-1-ol (768mg, 6mmol) and KOH (336mg, 6mmol) were placed in a 50mL two-mouth reaction bottle and sealed, and nitrogen was replaced three times. DMF (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, the reaction solution was concentrated and dissolved in an organic solvent, dichloromethane, and methanol was precipitated to obtain solid 2, which (693 mg, 1 mmol), ACR2 (5106 mg, 30 mmol) and tert-butyl peroxide (87 mg, 1.5% m 总 ) was placed in a 50 mL two-necked reaction bottle and sealed, and nitrogen was replaced three times. Toluene (10 mL) was injected into the reaction bottle and reacted at 65°C for 24 h. After the reaction was completed and cooled to room temperature, the reaction solution was concentrated and dissolved with an organic solvent, precipitated with methanol, purified by column chromatography, filtered and dried to obtain an elastomer as the target product with a yield of 77%.

[0064] Embodiment 5:

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

[0066]

[0067] Will (420mg, 1mmol), 4,7-dibromo-5-fluoro-2,1,3-benzothiadiazole (312mg, 1mmol), TBAB (32mg, 0.1mmol), tetrakistriphenylphosphine palladium (115mg, 0.1mmol) were placed in a 50mL two-mouth reaction bottle and sealed, and nitrogen was replaced three times. A 2mol / L K2CO3 aqueous solution (4mL) and chloroform (15mL) were injected into the reaction bottle and reacted at 95°C for 3 days. After the reaction was completed, it was cooled to room temperature, the reaction solution was concentrated and dissolved with an organic solvent dichloromethane, and methanol was precipitated to obtain solid 1; it (348mg, 1mmol), 8-nonene-1-ol (768mg, 6mmol) and KOH (336mg, 6mmol) were placed in a 50mL two-mouth reaction bottle and sealed, and nitrogen was replaced three times. Toluene (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 reaction solution was cooled to room temperature, the reaction solution was concentrated and dissolved with an organic solvent, dichloromethane, and methanol was precipitated to obtain solid 2, which (485 mg, 1 mmol), ACR3 (3483 mg, 30 mmol) and cumene hydroperoxide (60 mg, 1.5% m 总 ) was placed in a 50 mL two-necked reaction bottle and sealed, and nitrogen was replaced three times. DMF (10 mL) was injected into the reaction bottle and reacted at 65 ° C for 24 h. After the reaction was completed and cooled to room temperature, the reaction solution was concentrated and dissolved with an organic solvent, precipitated with methanol, purified by column chromatography, filtered and dried to obtain an elastomer as the target product, with a yield of 80%.

[0068] Embodiment 6:

[0069] When Ar is selected as Ar6 and ACR is selected as 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] Will (500mg, 1mmol), 4,7-dibromo-5-fluoro-2,1,3-benzothiadiazole (312mg, 1mmol), TBAB (32mg, 0.1mmol), tetrakistriphenylphosphine palladium (115mg, 0.1mmol) were placed in a 50mL two-mouth reaction bottle and sealed, and nitrogen was replaced three times. A 2mol / L K2CO3 aqueous solution (6mL) and DMF (24mL) were injected into the reaction bottle and reacted at 95°C for 3 days. After the reaction was completed, it was cooled to room temperature, the reaction solution was concentrated and dissolved with an organic solvent dichloromethane, and methanol was precipitated to obtain solid 1; it (428mg, 1mmol), 8-nonene-1-ol (768mg, 6mmol) and KOH (336mg, 6mmol) were placed in a 50mL two-mouth reaction bottle and sealed, and nitrogen was replaced three times. Toluene (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 reaction solution was cooled to room temperature, the reaction solution was concentrated and dissolved in an organic solvent, dichloromethane, and methanol was precipitated to obtain solid 2, which (565 mg, 1 mmol), ACR3 (3603 mg, 30 mmol) and azobisisobutyronitrile (62 mg, 1.5% m 总 ) was placed in a 50 mL two-necked reaction bottle and sealed, and nitrogen was replaced three times. Tetrahydrofuran (10 mL) was injected into the reaction bottle and reacted at 65° C. for 24 h. After the reaction was completed and cooled to room temperature, the reaction solution was concentrated and dissolved with an organic solvent, precipitated with methanol, purified by column chromatography, filtered and dried to obtain an elastomer as the target product with a yield of 88%.

[0072] Embodiment 7:

[0073] When Ar is selected as Ar7 and ACR is selected as 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] Will (600mg, 1mmol), 4,7-dibromo-5-fluoro-2,1,3-benzothiadiazole (312mg, 1mmol), TBAB (32mg, 0.1mmol), tetrakistriphenylphosphine palladium (115mg, 0.1mmol) were placed in a 50mL two-mouth reaction bottle and sealed, and nitrogen was replaced three times. A 2mol / L K2CO3 aqueous solution (7mL) and chloroform (21mL) were injected into the reaction bottle and reacted at 95°C for 3 days. After the reaction was completed, it was cooled to room temperature, the reaction solution was concentrated and dissolved with an organic solvent dichloromethane, and methanol was precipitated to obtain solid 1; it (528mg, 1mmol), 8-nonene-1-ol (768mg, 6mmol) and KOH (336mg, 6mmol) were placed in a 50mL two-mouth reaction bottle and sealed, and nitrogen was replaced three times. Chlorobenzene (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 reaction solution was cooled to room temperature, the reaction solution was concentrated and dissolved with an organic solvent, dichloromethane, and methanol was precipitated to obtain solid 2, which (665 mg, 1 mmol), ACR4 (4716 mg, 30 mmol) and cumene hydroperoxide (81 mg, 1.5% m 总 ) was placed in a 50 mL two-necked reaction bottle and sealed, and nitrogen was replaced three times. Dioxane (10 mL) was injected into the reaction bottle and reacted at 65 ° C for 24 h. After the reaction was completed and cooled to room temperature, the reaction solution was concentrated and dissolved with an organic solvent, precipitated with methanol, purified by column chromatography, filtered and dried to obtain an elastomer as the target product with a yield of 83%.

[0076] Embodiment 8:

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

[0078]

[0079] Will (854mg, 1mmol), 4,7-dibromo-5-fluoro-2,1,3-benzothiadiazole (312mg, 1mmol), TBAB (32mg, 0.1mmol), tetrakistriphenylphosphine palladium (115mg, 0.1mmol) were placed in a 50mL two-mouth reaction bottle and sealed, and nitrogen was replaced three times. A 2mol / L K2CO3 aqueous solution (10mL) and chlorobenzene (30mL) were injected into the reaction bottle and reacted at 95°C for 3 days. After the reaction was completed, it was cooled to room temperature, the reaction solution was concentrated and dissolved with an organic solvent of dichloromethane, and methanol was precipitated to obtain solid 1; it (782mg, 1mmol), 8-nonene-1-ol (768mg, 6mmol) and KOH (336mg, 6mmol) were placed in a 50mL two-mouth reaction bottle and sealed, and nitrogen was replaced 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, the reaction solution was concentrated and dissolved in an organic solvent, dichloromethane, and methanol was precipitated to obtain solid 2, which (919 mg, 1 mmol), ACR5 (3453 mg, 30 mmol) and dibenzoyl peroxide (66 mg, 1.5% m 总 ) was placed in a 50 mL two-necked reaction bottle and sealed, and nitrogen was replaced three times. DMF (10 mL) was injected into the reaction bottle and reacted at 65 ° C for 24 h. After the reaction was completed and cooled to room temperature, the reaction solution was concentrated and dissolved with an organic solvent, precipitated with methanol, purified by column chromatography, filtered and dried to obtain an elastomer as the target product, with a yield of 89%.

[0080] Embodiment 9:

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

[0082]

[0083] Will (608mg, 1mmol), 4,7-dibromo-5-fluoro-2,1,3-benzothiadiazole (312mg, 1mmol), TBAB (32mg, 0.1mmol), tetrakistriphenylphosphine palladium (115mg, 0.1mmol) were placed in a 50mL two-mouth reaction bottle and sealed, and nitrogen was replaced three times. A 2mol / L K2CO3 aqueous solution (7mL) and toluene (21mL) were injected into the reaction bottle and reacted at 95°C for 3 days. After the reaction was completed, it was cooled to room temperature, the reaction solution was concentrated and dissolved with an organic solvent of dichloromethane, and methanol was precipitated to obtain solid 1; it (536mg, 1mmol), 8-nonene-1-ol (768mg, 6mmol) and KOH (336mg, 6mmol) were placed in a 50mL two-mouth reaction bottle and sealed, and nitrogen was replaced three times. Chlorobenzene (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, the reaction solution was concentrated and dissolved in an organic solvent, dichloromethane, and methanol was precipitated to obtain solid 2, which (673 mg, 1 mmol), ACR6 (5286 mg, 30 mmol) and azobisisobutyronitrile (89 mg, 1.5% m 总 ) was placed in a 50 mL two-necked reaction bottle and sealed, and nitrogen was replaced three times. Tetrahydrofuran (10 mL) was injected into the reaction bottle and reacted at 65°C for 24 h. After the reaction was completed and cooled to room temperature, the reaction solution was concentrated and dissolved with an organic solvent, precipitated with methanol, purified by column chromatography, filtered and dried to obtain an elastomer as the target product with a yield of 78%.

[0084] Embodiment 10:

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

[0086]

[0087] Will (968mg, 1mmol), 4,7-dibromo-5-fluoro-2,1,3-benzothiadiazole (312mg, 1mmol), TBAB (32mg, 0.1mmol), tetrakistriphenylphosphine palladium (115mg, 0.1mmol) were placed in a 50mL two-mouth reaction bottle and sealed, and nitrogen was replaced three times. A 2mol / L K2CO3 aqueous solution (10mL) and DMF (30mL) were injected into the reaction bottle and reacted at 95°C for 3 days. After the reaction was completed, it was cooled to room temperature, the reaction solution was concentrated and dissolved with an organic solvent dichloromethane, and methanol was precipitated to obtain solid 1; it (896mg, 1mmol), 8-nonene-1-ol (768mg, 6mmol) and KOH (336mg, 6mmol) were placed in a 50mL two-mouth reaction bottle and sealed, and nitrogen was replaced 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 reaction solution was cooled to room temperature, the reaction solution was concentrated and dissolved in an organic solvent, dichloromethane, and methanol was precipitated to obtain solid 2, which (1033 mg, 1 mmol), ACR6 (5706 mg, 30 mmol) and tert-butyl peroxide (101 mg, 1.5% m 总 ) was placed in a 50 mL two-necked reaction bottle and sealed, and nitrogen was replaced three times. Tetrahydrofuran (10 mL) was injected into the reaction bottle and reacted at 65°C for 24 h. After the reaction was completed and cooled to room temperature, the reaction solution was concentrated and dissolved with an organic solvent, precipitated with methanol, purified by column chromatography, filtered and dried to obtain an elastomer as the target product. The yield was 76%.

[0088] Example 11: Preparation of OLED Device

[0089] After ultrasonic cleaning, ITO glass was treated with oxygen plasma. The sheet resistance of ITO glass was 10Ω / cm 2 . The hole injection layer is PEDOT or PVK, and the light-emitting layer is any one of ACR1-Ar1, ACR1-Ar2, ACR2-Ar3, ACR2-Ar4, ACR3-Ar5, ACR3-Ar6, ACR4-Ar7, ACR5-Ar8, ACR6-Ar9, ACR6-Ar10. The hole injection layer and the light-emitting layer are both made by spin coating. The cathode electrode uses Ca / Al or LiF / Al respectively. Table 1 is the electroluminescent performance table of the above-mentioned OLED devices, among which the maximum luminous brightness of the OLED device prepared based on ACR6-Ar10 is 13274cd / m 2 ; The elongation of ACR1-Ar2 can reach 500%.

[0090] Table 1 Electroluminescent properties of OLED devices

[0091]

[0092] The above are embodiments of the present invention. It should be noted that the present invention is not limited to these embodiments. These embodiments are only for a better understanding of the present invention. Any equivalent changes made according to the technical solution of the present invention belong to the protection scope of the present invention.

Claims

1. A main chain conjugated intrinsically stretchable electroluminescent elastomer, characterized in that the structure has the following general formula: Wherein m, n represent the number of repeating units of the component, Ar represents the conjugated structure, and ACR represents the acrylate side chain.

2. The main chain conjugated intrinsically stretchable electroluminescent elastomer according to claim 1, characterized in that: The conjugated structure represented by Ar is selected from one or more of the following molecular structures: Where R is C1-C 20 A straight or branched alkyl or alkoxy chain, * is the point of attachment.

3. The main chain conjugated intrinsically stretchable electroluminescent elastomer according to claim 1, characterized in that: The monomer corresponding to the acrylic ester side chain represented by ACR is one of the following molecular structures: Where R' is C1-C 10 A straight or branched alkyl chain.

4. A method for preparing a main chain conjugated intrinsically stretchable electroluminescent elastomer as claimed in any one of claims 1 to 3, characterized in that: The preparation method comprises the following steps: 4,7-Dibromo-5-fluoro-2,1,3-benzothiadiazole is used as a raw material to construct a rigid main chain of a donor-acceptor structure; the second step is to use the rigid main chain and 8-nonen-1-ol as units to construct a side chain grafting double bond site; the third step is to graft the ACR acrylate material with the main chain, and prepare the main chain conjugated intrinsic stretchable electroluminescent elastomer by free radical polymerization under the conditions of organic solvent, additive and initiator. The reaction equation is as follows:

5. The method for preparing a main chain conjugated intrinsically stretchable electroluminescent elastomer according to claim 4, characterized in that: The first step includes the following: (1) Under nitrogen protection, monomer 4,7-dibromo-5-fluoro-2,1,3-benzothiadiazole is dissolved in an organic solvent, and an additive and an initiator are added, and the reaction is carried out at 95-105°C; (2) After the reaction is completed, the reaction solution is cooled to room temperature, concentrated, and then dissolved with an organic good solvent, and the poor solvent is precipitated to obtain a solid; The second step includes the following: (3) dissolving the solid obtained in (2) and 8-nonen-1-ol in an organic solvent, adding an additive and an initiator, and reacting at 110-130° C.; (4) After the reaction is completed, the reaction solution is cooled to room temperature, concentrated, and then dissolved with an organic good solvent, and the poor solvent is precipitated to obtain a solid; The third step includes the following: (5) dissolving the solid obtained in (4) and the acrylic acid ester monomer in an organic solvent, adding additives and an initiator, React at 65-75°C; (6) After the reaction is completed, the elastomer is obtained through extraction, sedimentation, filtration and drying, which is the target product, the main chain conjugated intrinsic stretchable electroluminescent elastomer.

6. The method for preparing a main chain conjugated intrinsically stretchable electroluminescent elastomer according to claim 4, characterized in that: In the first step, 1 mmol The monomers are dissolved in an organic solvent, and additives and initiators are added.

7. The method for preparing a main chain conjugated intrinsically stretchable electroluminescent elastomer according to claim 4, characterized in that: The organic solvent is selected from dioxane, toluene, chlorobenzene, DMF, and chloroform; the additive is selected from tetrahydrofuran, TBAB, KOH, and K2CO3; and the initiator is selected from palladium-based metal catalysts, azobisisobutyronitrile, azobisisoheptanenitrile, tert-butyl peroxide, dibenzoyl peroxide, dodecyl peroxide, tert-butyl peroxypivalate, diisopropyl peroxydicarbonate, potassium persulfate, cumene hydroperoxide, and cyclohexyl peroxydicarbonate.

8. An application of a main chain conjugated intrinsically stretchable electroluminescent elastomer as claimed in any one of claims 1 to 3, characterized in that: This type of elastomer is used in flexible and stretchable electronic fields including flexible and stretchable organic electroluminescent devices, electronic paper, soft robots, organic photovoltaics, flexible energy storage, and artificial intelligence.

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