Main chain conjugated intrinsic stretchable thermal delay fluorescent 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 thermal delay fluorescent elastomer as well as a preparation method and application thereof. The elastomer is prepared through free radical polymerization by taking a high-efficiency luminous TADF conjugated unit as a main chain and acrylic ester as a flexible side chain. The innovation of the invention lies in that a flexible acrylate side chain is introduced into a rigid efficient electroluminescent TADF 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 good 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 intrinsic stretchable thermal delayed fluorescence (TADF) elastomer. Background Art

[0002] Electroluminescent (EL) devices have significant advantages in information visualization, wireless signals, power transmission and medical treatment. With the development of smart home, biomedicine, information energy and wearable devices, the demand for stretchable electroluminescent materials is increasing. Such stretchable electroluminescent devices will be used as displays on the skin, optical sensors (for example, for monitoring blood oxygen saturation), wearable imaging systems or implantable optical stimulation (for example, for optogenetics), etc. However, the current preparation of stretchable electroluminescent materials is through physical blending, which is easy to cause phase separation and has poor stretching effect.

[0003] Organic Light Emitting Diodes (OLEDs) have many advantages such as active luminescence, all-solid-state, low driving voltage, high efficiency, fast response speed, wide viewing angle, simple manufacturing process, and large-area and flexible display, so they have become the transformation and design direction of stretchable electroluminescent devices. Electroluminescent materials are divided into two groups according to the luminescence mechanism: one group is composed of fluorescent materials using singlet excitons, and the other group is composed of phosphorescent and thermal delayed fluorescence (TADF) materials using triplet excitons. Among them, phosphorescent OLEDs require the use of rare precious metals (such as Ir and Pt), so from the perspective of cost and biosafety, TADF materials are more suitable for stretchable electroluminescent applications. However, TADF materials still inevitably sacrifice some performance characteristics, including EL efficiency, brightness, driving voltage and switching speed to achieve stretchability. .

[0004] In summary, it is crucial to improve the stretchability of TADF materials from a molecular structure perspective while maintaining and improving their original optoelectronic properties. Summary of the invention

[0005] In response to the above technical problems, the present invention provides a main chain conjugated intrinsic stretchable thermal delayed fluorescence (TADF) elastomer and a preparation method and application thereof. The TADF conjugated rigid main chain and the polyacrylate flexible side chain are combined into a comb-like structure by free radical polymerization chemical cross-linking, thereby achieving both high stretchability and good photoelectric properties of the elastomer.

[0006] The technical solution adopted by the present invention is as follows:

[0007] The present invention provides a main chain conjugated intrinsic stretchable thermal delayed fluorescence (TADF) elastomer, which has the following general structural formula:

[0008]

[0009] Wherein, X represents the molar ratio of the component, and X<0.5, n represents the repeating unit of the component, Ar represents a conjugated structure, and ACR represents an acrylate side chain.

[0010] The conjugated structure represented by Ar is selected from one or more of the following molecular structures:

[0011]

[0012] Among them, * indicates the connection point.

[0013] The monomer corresponding to the acrylic ester side chain represented by ACR is one of the following molecular structures:

[0014]

[0015] Where R' is C 1 -C 10 A straight or branched alkyl or alkoxy chain.

[0016] The present invention also provides a method for preparing the main chain conjugated intrinsic stretchable thermal delayed fluorescence (TADF) elastomer. The first step is to use monomers and 3,6-dibromo-9-vinyl-9H-carbazole as raw materials to construct a rigid main chain with a fully conjugated structure. The second step is to graft the rigid main chain with ACR acrylic ester materials, and prepare the main chain conjugated intrinsic stretchable TADF elastomer by free radical polymerization under the conditions of organic solvent, additives and initiator. The reaction equation is as follows:

[0017]

[0018] Specifically, the preparation method of the main chain conjugated intrinsic stretchable thermal delayed fluorescent elastomer is carried out according to the following steps: (1) under nitrogen protection conditions, first and 3,6-dibromo-9-vinyl-9H-carbazole are dissolved in an organic solvent, the additive and the initiator are respectively injected into a reaction vessel, and the reaction is carried out at 95° C. for 3 days;

[0019] (2) After the reaction is completed, cool to room temperature, concentrate the reaction solution and dissolve it in an organic good solvent, and precipitate the poor solvent to obtain a solid. (3) Dissolve the solid and ACR monomer in an organic solvent and add them together. Add additives and initiators to the reaction vessel and react at 65°C for 24 hours.

[0020] (4) After the reaction is completed and cooled to room temperature, the reaction solution is concentrated and dissolved with an organic solvent, precipitated with methanol, and purified by column chromatography.

[0021] Then use n-hexane, methanol, and acetone solvents for Soxhlet extraction, and extract for 24-72 hours respectively. Then use methanol solvent to precipitate again.

[0022] The elastomer obtained after filtration and drying is the target product.

[0023] Wherein, in the first step, 0.1mmol The monomer is dissolved in 10-20 mL of an organic solvent, and 0.05 mmol of an additive and 0.05 mol of an initiator are added.

[0024] The organic solvent is selected from one or more of dioxane, toluene, chlorobenzene, DMF, chloroform, and tetrahydrofuran, and the additive is selected from TBAB, KOH, K 2 CO 3 The initiator is selected from one or more of palladium-based metal catalysts, azobisisobutyronitrile, azobisisoheptylnitrile, dibenzoyl peroxide, dodecyl peroxide, tert-butyl peroxypivalate, tert-butyl hydroperoxide, diisopropyl peroxydicarbonate, potassium persulfate, cumene hydroperoxide, and cyclohexyl peroxydicarbonate.

[0025] The present invention also provides the application of this type of main chain conjugated intrinsic stretchable TADF 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.

[0026] The present invention has the following beneficial effects:

[0027] 1. The present invention provides a main chain conjugated intrinsic stretchable thermal delayed fluorescence (TADF) elastomer as a photoelectric functional layer material, which can be applied to stretchable electroluminescent devices.

[0028] 2. By chemical cross-linking, flexible acrylate side chains were introduced for the first time into the rigid and efficient electroluminescent TADF conjugated main chain to form a rod-like bottle brush structure, which not only improved the intrinsic stretchability of the elastomer, but also had excellent luminescence properties and high carrier mobility. At the same time, it solved the intrinsic non-stretchability problem of traditional organic optoelectronic materials and the compatibility technical difficulties of TADF properties that traditional elastomers do not have.

[0029] 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 TADF elastomer with important application potential.

[0030] 4. In addition, by using TADF elastomer as the light-emitting layer material, the preparation of stretchable electroluminescent devices with high stretchability, high stability and high efficiency was achieved through solution processing. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 It is a fluorescence lifetime diagram of a part of the elastomer according to an embodiment of the present invention;

[0032] Figure 2 It is a mechanical curve diagram of a part of the elastic body of an embodiment of the present invention. DETAILED DESCRIPTION

[0033] 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.

[0034] The present invention relates to a main chain conjugated intrinsic stretchable thermal delayed fluorescence (TADF) elastomer, which has the following general structural formula:

[0035]

[0036] Wherein, X represents the molar ratio of the component, and X<0.5, n represents the repeating unit of the component, Ar represents the conjugated structure, and ACR represents the acrylate side chain;

[0037] The conjugated structure represented by Ar is selected from one or more of the following molecular structures:

[0038]

[0039] Among them, * indicates the connection point.

[0040] The monomer corresponding to the acrylic ester side chain represented by ACR is one of the following molecular structures:

[0041]

[0042] Where R' is C 1 -C 10 A straight or branched alkyl or alkoxy chain.

[0043] The preparation method of this type of main chain conjugated intrinsic stretchable thermal delayed fluorescence (TADF) elastomer is as follows: the first step is to use monomers and 3,6-dibromo-9-vinyl-9H-carbazole as raw materials to construct a rigid main chain with a fully conjugated structure. The second step is to graft the rigid main chain with ACR acrylic ester materials, and prepare the main chain conjugated intrinsic stretchable TADF elastomer by free radical polymerization under the conditions of organic solvent, additives and initiator.

[0044] Embodiment 1:

[0045] This embodiment relates to a main chain conjugated intrinsic stretchable thermal delayed fluorescent elastomer, wherein Ar is Ar1, ACR is ACR1, R' is C 4 A straight chain alkyl group, X is 0.1, that is, elastomer ACR1-Ar1. The preparation process of the elastomer ACR2-Ar1 is as follows:

[0046]

[0047] Will (106 mg, 0.1 mmol), (218 mg, 0.5 mmol), 3,6-dibromo-9-vinyl-9H-carbazole (140 mg, 0.4 mmol), TBAB (16 mg, 0.05 mmol), tetrakistriphenylphosphine palladium (57 mg, 0.05 mmol) were placed in a 50 mL two-necked reaction bottle and sealed, and nitrogen was replaced three times. K with a concentration of 2 mol / L was injected into the reaction bottle. 2 CO 3 Aqueous solution (4mL), toluene (12mL), react at 95℃ for 2 days, then add 0.5mL bromobenzene to react for 1 day. After the reaction is completed, cool to room temperature, concentrate the reaction solution and dissolve it with organic solvent dichloromethane, and precipitate with methanol to obtain a solid; put it (142mg, 0.1mmol), ACR1 (1282mg, 10mmol) and AIBN (16mg, 0.1mmol) into a 50mL two-necked reaction bottle and seal it, and replace nitrogen three times. Inject tetrahydrofuran (10mL) into the reaction bottle and react at 65℃ for 24h. After the reaction is completed and cooled to room temperature, the reaction solution is 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%.

[0048] The photoelectric and mechanical properties of the elastomer ACR1-Ar1 were tested. The results are as follows Figure 1 and Figure 2 shown.

[0049] Embodiment 2:

[0050] The main chain conjugated intrinsic stretchable thermal delayed fluorescent elastomer involved in this embodiment is selected to be Ar2, ACR is ACR1, and R' is C 8 A straight chain alkyl group, X is 0.1. That is, elastomer ACR1-Ar2. The preparation process of the elastomer ACR1-Ar2 is as follows:

[0051]

[0052] Will (114 mg, 0.1 mmol), (218 mg, 0.5 mmol), 3,6-dibromo-9-vinyl-9H-carbazole (140 mg, 0.4 mmol), TBAB (16 mg, 0.05 mmol), tetrakistriphenylphosphine palladium (57 mg, 0.05 mmol) were placed in a 50 mL two-necked reaction bottle and sealed, and nitrogen was replaced three times. K with a concentration of 2 mol / L was injected into the reaction bottle. 2 CO 3 Aqueous solution (6mL), chloroform (15mL), react at 95℃ for 2 days, then add 0.5mL bromobenzene to react for 1 day. After the reaction is completed, cool to room temperature, concentrate the reaction solution and dissolve it with organic solvent chloroform, precipitate with ethanol to obtain a solid; put it (151mg, 0.1mmol), ACR1 (1843mg, 10mmol) and azobisisobutyronitrile (25mg, 0.1mmol) into a 50mL two-mouth reaction bottle and seal it, and replace nitrogen three times. Inject dioxane (10mL) into the reaction bottle and react at 65℃ for 24h. After the reaction is completed and cooled to room temperature, the reaction solution is concentrated and dissolved with chloroform, precipitated with ethanol, purified by column chromatography, filtered and dried to obtain an elastomer as the target product with a yield of 73%.

[0053] The photoelectric and mechanical properties of the elastomer ACR1-Ar2 were tested. Figure 1 and Figure 2 shown.

[0054] Embodiment 3:

[0055] The main chain conjugated intrinsic stretchable thermal delayed fluorescent elastomer involved in this embodiment is selected to be Ar3, ACR is ACR2, and R' is C 4 The straight chain alkyl group, X is 0.1, that is, the elastomer ACR2-Ar3. The preparation process of the elastomer ACR2-Ar3 is as follows:

[0056]

[0057] Will (127 mg, 0.1 mmol), (218 mg, 0.5 mmol), 3,6-dibromo-9-vinyl-9H-carbazole (140 mg, 0.4 mmol), TBAB (16 mg, 0.05 mmol), tetrakistriphenylphosphine palladium (57 mg, 0.05 mmol) were placed in a 50 mL two-necked reaction bottle and sealed, and nitrogen was replaced three times. K with a concentration of 2 mol / L was injected into the reaction bottle. 2 CO 3Aqueous solution (4mL), chlorobenzene (10mL), react at 95℃ for 2 days, then add 0.5mL bromobenzene and react for 1 day. After the reaction is completed, cool to room temperature, concentrate the reaction solution and dissolve it with organic solvent chloroform, and precipitate with methanol to obtain a solid; put it (164mg, 0.1mmol), ACR2 (1422mg, 10mmol) and BPO (24mg, 0.1mmol) into a 50mL two-mouth reaction bottle and seal it, and replace nitrogen three times. Inject toluene (10mL) into the reaction bottle and react at 65℃ for 24h. After the reaction is completed and cooled to room temperature, the reaction solution is 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%.

[0058] The photoelectric and mechanical properties of the elastomer ACR2-Ar3 were tested. Figure 1 and Figure 2 shown.

[0059] Embodiment 4:

[0060] The main chain conjugated intrinsic stretchable thermal delayed fluorescent elastomer involved in this embodiment is selected to be Ar4, ACR is ACR2, and R' is C 6 The straight chain alkyl group, x is 0.2, that is, the elastomer ACR2-Ar4. The preparation process of the elastomer ACR2-Ar4 is:

[0061]

[0062] Will (220 mg, 0.2 mmol), (218 mg, 0.5 mmol), 3,6-dibromo-9-vinyl-9H-carbazole (105 mg, 0.3 mmol), TBAB (16 mg, 0.05 mmol), tetrakistriphenylphosphine palladium (57 mg, 0.05 mmol) were placed in a 50 mL two-necked reaction bottle and sealed, and nitrogen was replaced three times. K with a concentration of 2 mol / L was injected into the reaction bottle. 2 CO 3Aqueous solution (3mL), dioxane (12mL), react at 95℃ for 2 days, then add 0.5mL bromobenzene to react for 1 day. After the reaction is completed, cool to room temperature, concentrate the reaction solution and dissolve it with organic solvent dichloromethane, precipitate with ethanol to obtain a solid; put it (147mg, 0.1mmol), ACR2 (1702mg, 10mmol) and TBHP (19mg, 0.1mmol) into a 50mL two-mouth reaction bottle and seal it, and replace nitrogen three times. Inject chlorobenzene (10mL) into the reaction bottle and react at 65℃ for 24h. After the reaction is completed and cooled to room temperature, the reaction solution is concentrated and dissolved with dichloromethane, precipitated with ethanol, purified by column chromatography, filtered and dried to obtain an elastomer as the target product with a yield of 77%.

[0063] The photoelectric and mechanical properties of the elastomer ACR2-Ar4 were tested. Figure 1 and Figure 2 shown.

[0064] Embodiment 5:

[0065] The main chain conjugated intrinsic stretchable thermal delayed fluorescent elastomer involved in this embodiment is selected to be Ar5, ACR is ACR2, and R' is C 4 The straight chain alkyl group, x is 0.2, that is, the elastomer ACR2-Ar5. The preparation process of the elastomer ACR2-Ar5 is:

[0066]

[0067] Will (120 mg, 0.2 mmol), (218 mg, 0.5 mmol), 3,6-dibromo-9-vinyl-9H-carbazole (105 mg, 0.3 mmol), TBAB (16 mg, 0.05 mmol), tetrakistriphenylphosphine palladium (57 mg, 0.05 mmol) were placed in a 50 mL two-necked reaction bottle and sealed, and nitrogen was replaced three times. K with a concentration of 2 mol / L was injected into the reaction bottle. 2 CO 3Aqueous solution (4mL), DMF (12mL), react at 95℃ for 3-2 days, then add 0.5mL bromobenzene to react for 1 day. After the reaction is completed, cool to room temperature, concentrate the reaction solution and dissolve it with organic solvent THF, precipitate with deionized water to obtain a solid; put it (96mg, 0.1mmol), ACR2 (1161mg, 10mmol) and CHP (15mg, 0.1mmol) into a 50mL two-necked reaction bottle and seal it, and replace nitrogen three times. Inject tetrahydrofuran (10mL) into the reaction bottle and react at 65℃ for 24h. After the reaction is completed and cooled to room temperature, the reaction solution is concentrated and dissolved with THF, precipitated with deionized water, purified by column chromatography, filtered and dried to obtain an elastomer as the target product with a yield of 80%.

[0068] The photoelectric and mechanical properties of the elastomer ACR2-Ar5 were tested. Figure 1 and Figure 2 shown.

[0069] Embodiment 6:

[0070] The main chain conjugated intrinsic stretchable thermal delayed fluorescent elastomer involved in this embodiment is selected to be Ar6, ACR is ACR3, R' is C 3 When x is 0.2, the elastomer ACR3-Ar6 is prepared as follows:

[0071]

[0072] Will (130 mg, 0.12 mmol), (218 mg, 0.5 mmol), 3,6-dibromo-9-vinyl-9H-carbazole (105 mg, 0.3 mmol), TBAB (16 mg, 0.05 mmol), tetrakistriphenylphosphine palladium (57 mg, 0.05 mmol) were placed in a 50 mL two-necked reaction bottle and sealed, and nitrogen was replaced three times. K with a concentration of 2 mol / L was injected into the reaction bottle. 2 CO 3Aqueous solution (4mL), toluene (15mL), react at 95℃ for 3-2 days, then add 0.5mL bromobenzene to react for 1 day. After the reaction is completed, cool to room temperature, concentrate the reaction solution and dissolve it with organic solvent THF, and precipitate with methanol to obtain a solid; put it (102mg, 0.1mmol), ACR3 (1301mg, 10mmol) and BPO (24mg, 0.1mmol) into a 50mL two-necked reaction bottle and seal it, and replace nitrogen three times. Inject DMF (10mL) into the reaction bottle and react at 65℃ for 24h. After the reaction is completed and cooled to room temperature, the reaction solution is concentrated and dissolved with THF, precipitated with methanol, purified by column chromatography, filtered and dried to obtain an elastomer as the target product with a yield of 88%.

[0073] The photoelectric and mechanical properties of the elastomer ACR3-Ar6 were tested. Figure 1 and Figure 2 shown.

[0074] Embodiment 7:

[0075] The main chain conjugated intrinsic stretchable thermal delayed fluorescent elastomer involved in this embodiment is selected to be Ar7, ACR is ACR4, and R' is C 2 When x is 0.3, the elastomer ACR4-Ar7 is prepared as follows:

[0076]

[0077] Will (240 mg, 0.3 mmol), (218 mg, 0.5 mmol), 3,6-dibromo-9-vinyl-9H-carbazole (700 mg, 0.2 mmol), TBAB (16 mg, 0.05 mmol), tetrakistriphenylphosphine palladium (57 mg, 0.05 mmol) were placed in a 50 mL two-necked reaction bottle and sealed, and nitrogen was replaced three times. K with a concentration of 2 mol / L was injected into the reaction bottle. 2 CO 3Aqueous solution (6mL), chlorobenzene (15mL), react at 95℃ for 2 days, then add 0.5mL bromobenzene to react for 1 day. After the reaction is completed, cool to room temperature, concentrate the reaction solution and dissolve it with organic solvent chloroform, and precipitate with methanol to obtain a solid; put it (117mg, 0.1mmol), ACR4 (1572mg, 10mmol) and CHP (15mg, 0.1mmol) into a 50mL two-mouth reaction bottle and seal it, and replace nitrogen three times. Inject dioxane (10mL) into the reaction bottle and react at 65℃ for 24h. After the reaction is completed and cooled to room temperature, the reaction solution is concentrated and dissolved with chloroform, precipitated with methanol, purified by column chromatography, filtered and dried to obtain an elastomer as the target product with a yield of 83%.

[0078] The photoelectric and mechanical properties of the elastomer ACR4-Ar7 were tested. Figure 1 and Figure 2 shown.

[0079] Embodiment 8:

[0080] The main chain conjugated intrinsic stretchable thermal delayed fluorescent elastomer involved in this embodiment is selected to be Ar8, ACR is ACR5, R' is C 3 When x is 0.3, the elastomer ACR5-Ar8 is obtained. The preparation process of the elastomer ACR5-Ar8 is as follows:

[0081]

[0082] Will (144 mg, 0.3 mmol), (218 mg, 0.5 mmol), 3,6-dibromo-9-vinyl-9H-carbazole (70 mg, 0.2 mmol), TBAB (16 mg, 0.05 mmol), tetrakistriphenylphosphine palladium (57 mg, 0.05 mmol) were placed in a 50 mL two-necked reaction bottle and sealed, and nitrogen was replaced three times. K with a concentration of 2 mol / L was injected into the reaction bottle. 2 CO 3Aqueous solution (6mL), DMF (20mL), react at 95℃ for 2 days, then add 0.5mL bromobenzene to react for 1 day. After the reaction is completed, cool to room temperature, concentrate the reaction solution and dissolve it with organic solvent dichloromethane, and precipitate with methanol to obtain a solid; put it (109mg, 0.1mmol), ACR5 (1151mg, 10mmol) and AIBN (16mg, 0.1mmol) into a 50mL two-mouth reaction bottle and seal it, and replace nitrogen three times. Inject chloroform (10mL) into the reaction bottle and react at 65℃ for 24h. After the reaction is completed and cooled to room temperature, the reaction solution is concentrated and dissolved with THF, precipitated with methanol, purified by column chromatography, filtered and dried to obtain an elastomer as the target product with a yield of 89%.

[0083] The photoelectric and mechanical properties of the elastomer ACR5-Ar8 were tested. Figure 1 and Figure 2 shown.

[0084] Embodiment 9:

[0085] The main chain conjugated intrinsic stretchable thermal delayed fluorescent elastomer involved in this embodiment is selected to be Ar9, ACR is ACR6, and R' is C 2 When x is 0.4, the elastomer ACR6-Ar9 is prepared as follows:

[0086]

[0087] Will (2488mg, 0.4mmol), (218 mg, 0.5 mmol), 3,6-dibromo-9-vinyl-9H-carbazole (35 mg, 0.1 mmol), TBAB (16 mg, 0.05 mmol), tetrakistriphenylphosphine palladium (57 mg, 0.05 mmol) were placed in a 50 mL two-necked reaction bottle and sealed, and nitrogen was replaced three times. K with a concentration of 2 mol / L was injected into the reaction bottle. 2 CO 3Aqueous solution (4mL), dioxane (12mL), react at 95℃ for 2 days, then add 0.5mL bromobenzene to react for 1 day. After the reaction is completed, cool to room temperature, concentrate the reaction solution and dissolve it with organic solvent dichloromethane, precipitate with ethanol to obtain a solid; put it (104mg, 0.1mmol), ACR6 (1762mg, 10mmol) and ADN (25mg, 0.1mmol) into a 50mL two-mouth reaction bottle and seal it, and replace nitrogen three times. Inject toluene (10mL) into the reaction bottle and react at 65℃ for 24h. After the reaction is completed and cooled to room temperature, the reaction solution is concentrated and dissolved with dichloromethane, precipitated with ethanol, purified by column chromatography, filtered and dried to obtain an elastomer as the target product with a yield of 78%.

[0088] The photoelectric and mechanical properties of the elastomer ACR6-Ar9 were tested. Figure 1 and Figure 2 shown.

[0089] Embodiment 10:

[0090] The main chain conjugated intrinsic stretchable thermal delayed fluorescent elastomer involved in this embodiment is selected to be Ar10, ACR is ACR6, and R' is C 3 When x is 0.4, the elastomer ACR6-Ar10 is obtained. The preparation process of the elastomer ACR6-Ar10 is as follows:

[0091]

[0092] Will (260 mg, 0.4 mmol), (218 mg, 0.5 mmol), 3,6-dibromo-9-vinyl-9H-carbazole (35 mg, 0.1 mmol), TBAB (16 mg, 0.05 mmol), tetrakistriphenylphosphine palladium (57 mg, 0.05 mmol) were placed in a 50 mL two-necked reaction bottle and sealed, and nitrogen was replaced three times. K with a concentration of 2 mol / L was injected into the reaction bottle. 2 CO 3Aqueous solution (4mL), chlorobenzene (10mL), react at 95℃ for 2 days, then add 0.5mL bromobenzene to react for 1 day. After the reaction is completed, cool to room temperature, concentrate the reaction solution and dissolve it with organic solvent THF, and precipitate with methanol to obtain a solid; put it (101mg, 0.1mmol), ACR6 (1902mg, 10mmol) and TBHP (19mg, 0.1mmol) into a 50mL two-necked reaction bottle and seal it, and replace nitrogen three times. Inject dioxane (10mL) into the reaction bottle and react at 65℃ for 24h. After the reaction is completed and cooled to room temperature, the reaction solution is concentrated and dissolved with THF, precipitated with methanol, purified by column chromatography, filtered and dried to obtain an elastomer as the target product with a yield of 76%.

[0093] The photoelectric and mechanical properties of the elastomer ACR6-Ar10 were tested. Figure 1 and Figure 2 shown.

[0094] Example 11: Preparation of OLED Device

[0095] 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, ACR2-Ar5, ACR3-Ar6, ACR4-Ar7, ACR5-Ar8, ACR6-Ar9, and ACR6-Ar10. The hole injection layer and the light-emitting layer are both made by spin coating. The cathode electrode is Ca / Al or LiF / Al.

[0096] The photoelectric performance of the OLED device was tested, and the results are shown in Table 1 and Table 2. Among them, the maximum luminous brightness of the OLED device prepared based on the elastomer ACR6-Ar10 is 16111 cd / m 2 ; The elongation of ACR-Ar6 can reach 400%.

[0097] Table 1. GPC and TGA tables of elastomers of some embodiments of the present invention

[0098]

[0099] Table 2. Electroluminescent properties of elastomers in some embodiments of the present invention

[0100]

[0101] 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 thermally delayed fluorescent elastomer, characterized in that the structure has the following general formula: Wherein X represents the molar ratio of the component, and X<0.5, n represents the repeating unit of the component, Ar represents the conjugated structure, and ACR represents the acrylic ester side chain.

2. The main chain conjugated intrinsic stretchable thermally delayed fluorescent 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: Among them, * indicates the connection point.

3. The main chain conjugated intrinsic stretchable thermally delayed fluorescent 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 or alkoxy chain.

4. A method for preparing a main chain conjugated intrinsic stretchable thermally delayed fluorescent elastomer as claimed in any one of claims 1 to 3, characterized in that: The preparation method comprises the following steps: and 3,6-dibromo-9-vinyl-9H-carbazole as raw materials to construct a conjugated rigid main chain; in the second step, the rigid main chain is grafted with ACR acrylic ester materials, and the main chain conjugated intrinsic stretchable thermal delayed fluorescent elastomer is prepared by free radical polymerization under the conditions of organic solvent, additives and initiator. The reaction equation is as follows:

5. The method for preparing the main chain conjugated intrinsic stretchable thermal delayed fluorescent elastomer according to claim 4, characterized in that: The first step includes the following: (1) Under nitrogen protection, monomer and 3,6-dibromo-9-vinyl-9H-carbazole are dissolved in an organic solvent, an additive and an initiator are added, and the reaction is carried out at 95°C; (2) After the reaction is completed, the reaction solution is cooled to room temperature, concentrated, and then dissolved with an organic solvent. The poor solvent precipitates to obtain a solid; The second step includes the following: (3) dissolving the solid obtained in (2) and an acrylic acid ester monomer in an organic solvent, adding an additive and an initiator, and reacting at 65° C.; (4) 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 thermal delayed fluorescent elastomer.

6. The method for preparing the main chain conjugated intrinsic stretchable thermal delayed fluorescent elastomer according to claim 4, characterized in that: In the first step, 0.1 mmol The monomer is dissolved in 10-20 mL of an organic solvent, and 0.05 mmol of an additive and 0.05 mmol of an initiator are added.

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

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

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