Main chain conjugated intrinsically stretchable thermally delayed fluorescence elastomer, preparation and applications thereof

Abstract

The application belongs to the technical field of photoelectric materials and application, and discloses a main chain conjugated intrinsic stretchable thermal retardation fluorescent elastomer and a preparation method and application thereof.The elastomer is prepared by taking a high-efficiency TADF conjugated unit as a main chain and an acrylate as a flexible side chain through free radical polymerization.The innovation of the application is that the flexible acrylate side chain is first introduced into the rigid high-efficiency electroluminescent TADF conjugated main chain in a chemical crosslinking manner to form a rod-shaped bottle brush structure, so that the elastomer has good photoelectric properties on the basis of improving the intrinsic stretchability of the elastomer; the structure is novel, the design strategy is unique, the problems of intrinsic non-stretchability of traditional conjugated luminescent materials and the problems of high-performance photoelectric properties which are not possessed by traditional elastomers are solved at the same time; and the elastomer is used as a luminescent 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 photoelectric materials and applications, and particularly relates to design, synthesis and application of a main-chain conjugated intrinsic stretchable thermally activated delayed fluorescence (TADF) elastomer. BACKGROUND

[0002] Electroluminescent (EL) devices have significant advantages in information visualization, wireless signals, power transmission and medical treatment. With the development of smart home, biological medicine, 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 light emission, full solid state, low driving voltage, high efficiency, fast response speed, wide viewing angle, simple manufacturing process and realization of large area and flexible display, and thus become the design direction of stretchable electroluminescent devices. Electroluminescent materials are divided into two groups according to the light emitting mechanism: one group is composed of fluorescent materials using singlet excitons, and the other group is composed of phosphorescent, thermally activated delayed fluorescence (TADF) substances using triplet excitons. Among them, phosphorescent OLEDs need to use rare noble metals (such as Ir and Pt), so from the cost and biological safety, 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 realize stretchability.

[0004] In summary, it is crucial to improve the stretchability of TADF materials from the molecular structure while maintaining and improving their original photoelectric properties. SUMMARY

[0005] In view of the above technical problems, the application provides a main-chain conjugated intrinsic stretchable thermally activated 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 structure through free radical polymerization chemical crosslinking, realizing the coexistence of high stretchability and good photoelectric properties of the elastomer.

[0006] The technical scheme adopted by the application is as follows:

[0007] The main-chain conjugated intrinsic stretchable thermally activated delayed fluorescence (TADF) elastomer provided by the application has the following structural general formula:

[0008]

[0009] wherein X represents the molar ratio of the components, 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] wherein * represents a connection point.

[0013] The acrylate side chain represented by ACR corresponds to one of the following molecular structures of a monomer:

[0014]

[0015] wherein R' is a C1-C 10 straight-chain or branched alkyl or alkoxy chain.

[0016] The present application also provides a preparation method of the main-chain conjugated intrinsically stretchable thermally delayed fluorescence (TADF) elastomer described above, in which 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 full conjugated structure. The second step is to graft the rigid main chain with ACR acrylate materials, and under the conditions of an organic solvent, an additive, and an initiator, to prepare the main-chain conjugated intrinsically stretchable TADF elastomer by a free radical polymerization method, and the reaction equation is as follows:

[0017]

[0018] Specifically, the preparation method of the main-chain conjugated intrinsically stretchable thermally delayed fluorescence elastomer is carried out according to the following steps: (1) under the condition of nitrogen protection, first dissolve and 3,6-dibromo-9-vinyl-9H-carbazole in an organic solvent, inject the additive and the initiator into the reaction container respectively, and react at 95°C for 3 days;

[0019] (2) After the reaction is completed, cool to room temperature, dissolve the reaction liquid with a good organic solvent, and precipitate the solid with a poor solvent.

[0020] (4) After cooling to room temperature after the reaction is over, the reaction solution is concentrated and dissolved with an organic solvent, precipitated with methanol, and purified by column chromatography. Then Soxhlet extraction is performed with n-hexane, methanol, and acetone solvents for 24-72 hours, respectively. Again, the TADF elastomer is precipitated with methanol solvent,

[0021] After suction filtration and drying, the elastomer is obtained as the target product.

[0022] In the first step, 0.1 mmol The monomer is dissolved in 10-20 mL of an organic solvent, 0.05 mmol of an additive is added, and 0.05 mol of an initiator.

[0023] The organic solvent is selected from one or more of dioxane, toluene, chlorobenzene, DMF, chloroform, and tetrahydrofuran, the additive is selected from TBAB, KOH, K2CO3, and the initiator is selected from one or more of a palladium-based metal catalyst, azobisisobutyronitrile, azobisisoheptyl nitrile, dibenzoyl peroxide, dodecanoyl peroxide, tert-butyl peroxypivalate, tert-butyl hydroperoxide, diisopropyl peroxydicarbonate, potassium persulfate, cumene hydroperoxide, and cyclohexyl peroxydicarbonate.

[0024] The application also provides applications of the main-chain conjugated intrinsically stretchable TADF elastomer. The elastomer can be 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.

[0025] The application has the following beneficial effects:

[0026] 1. The application provides a main-chain conjugated intrinsically stretchable thermal delayed fluorescence (TADF) elastomer as a photoelectric functional layer material, which can be applied to stretchable electroluminescent devices.

[0027] 2. The flexible acrylate side chain is introduced into the rigid and efficient electroluminescent TADF conjugated main chain in a chemical crosslinking manner 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 problems of intrinsic non-stretchability of traditional organic photoelectric materials and the compatibility technical difficulties of TADF characteristics not possessed by traditional elastomers.

[0028] 3. The design strategy of the elastomer is unique and novel, has excellent thermal stability, luminescent properties, film-forming property, and high intrinsic stretchability, and is a TADF elastomer with important application potential.

[0029] 4. In addition, the TADF elastomer is used as a luminescent layer material, and a stretchable electroluminescent device with high stretchability, high stability, and high efficiency is prepared by a solution processing method. Attached Figure Description

[0030] Figure 1 The fluorescence lifetime diagrams of some elastomers in embodiments of the present invention are shown.

[0031] Figure 2 This is a mechanical curve diagram of a portion of the elastomers in an embodiment of the present invention. Detailed Implementation

[0032] The technical solution of the present invention will be further described below with reference to the accompanying drawings and specific embodiments. It should be noted that the following embodiments are only some embodiments of the present invention, and are not intended to limit the present invention.

[0033] This invention relates to a main-chain conjugated intrinsically stretchable thermally delayed fluorescence (TADF) elastomer, which has the following general structural formula:

[0034]

[0035] Where 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;

[0036] The conjugated structure represented by Ar is selected from one or more of the following molecular structures:

[0037]

[0038] In this context, * indicates a connection point.

[0039] The monomer corresponding to the acrylate side chain represented by ACR has one of the following molecular structures:

[0040]

[0041] Where R' is C1-C 10 Straight-chain or branched alkyl or alkoxy chains.

[0042] The preparation method of this type of main-chain conjugated intrinsically stretchable thermally delayed fluorescence (TADF) elastomer is as follows: The first step is to use monomers... Using 3,6-dibromo-9-vinyl-9H-carbazole as a raw material, a rigid backbone with a fully conjugated structure was constructed. In the second step, the rigid backbone was grafted with ACR acrylate materials, and a conjugated intrinsically stretchable TADF elastomer was prepared via free radical polymerization under organic solvent, additive, and initiator conditions.

[0043] Example 1:

[0044] This embodiment relates to a main-chain conjugated intrinsically stretchable thermally delayed fluorescent elastomer, in which Ar is selected as Ar1, ACR as ACR1, R' as a C4 straight-chain alkyl group, and X is 0.1, i.e., elastomer ACR1-Ar1. The preparation process of the elastomer ACR2-Ar1 is as follows:

[0045]

[0046] 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), and tetraphenylphosphine palladium (57 mg, 0.05 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 (4 mL) and toluene (12 mL) were added to the reaction flask, and the reaction was carried out at 95 °C for 2 days. Then, 0.5 mL of bromobenzene was added, and the reaction was carried out for 1 day. After the reaction was completed, the mixture was cooled to room temperature, concentrated, and dissolved in the organic solvent dichloromethane. Methanol precipitated to obtain a solid. This solid (142 mg, 0.1 mmol), ACR1 (1282 mg, 10 mmol), and AIBN (16 mg, 0.1 mmol) were placed in a 50 mL two-necked reaction flask and sealed. Nitrogen gas was purged three times. 10 mL of tetrahydrofuran was 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%.

[0047] The photoelectric and mechanical properties of the elastomer ACR1-Ar1 were tested, and the results are as follows: Figure 1 and Figure 2 As shown.

[0048] Example 2:

[0049] The main-chain conjugated intrinsically stretchable thermally delayed fluorescent elastomer involved in this embodiment is selected with Ar as Ar2, ACR as ACR1, R' as a C8 straight-chain alkyl group, and X is 0.1. That is, elastomer ACR1-Ar2. The preparation process of elastomer ACR1-Ar2 is as follows:

[0050]

[0051] Will (114mg, 0.1mmol), 218 mg (0.5 mmol), 3,6-dibromo-9-vinyl-9H-carbazole (140 mg, 0.4 mmol), TBAB (16 mg, 0.05 mmol), and tetraphenylphosphine palladium (57 mg, 0.05 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 (15 mL) were added to the reaction flask, and the mixture was reacted at 95 °C for 2 days. Then, 0.5 mL of bromobenzene was added, and the reaction was continued for 1 day. After the reaction was complete, the mixture was cooled to room temperature, concentrated, dissolved in the organic solvent chloroform, and precipitated with ethanol to obtain a solid. This solid (151 mg, 0.1 mmol), ACR1 (1843 mg, 10 mmol), and azobisisobutyronitrile (25 mg, 0.1 mmol) were placed in a 50 mL two-necked reaction flask and sealed. Nitrogen gas was purged three times. Dioxane (10 mL) was 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 chloroform, precipitated with ethanol, purified by column chromatography, filtered, and dried to obtain the elastomer, which was the target product, with a yield of 73%.

[0052] The photoelectric and mechanical properties of the elastomer ACR1-Ar2 were tested, and the results are as follows: Figure 1 and Figure 2 As shown.

[0053] Example 3:

[0054] The main-chain conjugated intrinsically stretchable thermally delayed fluorescent elastomer involved in this embodiment is selected with Ar as Ar3, ACR as ACR2, R' as a C4 straight-chain alkyl group, and X as 0.1, i.e., elastomer ACR2-Ar3. The preparation process of the elastomer ACR2-Ar3 is as follows:

[0055]

[0056] Will (127mg, 0.1mmol), (218mg,0.5mmol), 3,6-dibromo-9-vinyl-9H-carbazole (140mg, 0.4mmol), TBAB (16mg, 0.05mmol), tetrakis(triphenylphosphine)palladium (57mg, 0.05mmol) were put into a 50mL two-necked flask and sealed, and the flask was replaced with nitrogen for three times. Concentrated aqueous K2CO3 solution (4mL) and chlorobenzene (10mL) were injected into the flask, and the reaction was carried out at 95°C for 2 days, and then 0.5mL bromobenzene was added and the reaction was carried out for 1 day. After the reaction was completed, the reaction solution was cooled to room temperature, concentrated, dissolved in chloroform, and precipitated in methanol to obtain a solid. The solid (164mg, 0.1mmol), ACR2 (1422mg, 10mmol) and BPO (24mg, 0.1mmol) were put into a 50mL two-necked flask and sealed, and the flask was replaced with nitrogen for three times. Toluene (10mL) was injected into the flask, and the reaction was carried out at 65°C for 24h. After the reaction was completed, the reaction solution was cooled to room temperature, concentrated, dissolved in chloroform, and precipitated in methanol. After column chromatography, filtration and drying, the elastomer was obtained as the target product, and the yield was 77%.

[0057] The photoelectric properties and mechanical properties of the elastomer ACR2-Ar3 were tested, and the results are shown in Figure 1 and Figure 2 .

[0058] Example 4:

[0059] This example relates to a main-chain conjugated intrinsic stretchable thermally delayed fluorescent elastomer, which selects Ar as Ar4, ACR as ACR2, R' as a straight-chain alkyl group C6, and X as 0.2, i.e., the elastomer ACR2-Ar4. The preparation process of the elastomer ACR2-Ar4 is as follows:

[0060]

[0061] (220mg,0.2mmol), ​218 mg (0.5 mmol), 3,6-dibromo-9-vinyl-9H-carbazole (105 mg, 0.3 mmol), TBAB (16 mg, 0.05 mmol), and tetraphenylphosphine palladium (57 mg, 0.05 mmol) were placed in a 50 mL two-necked reaction flask and sealed. Nitrogen gas was purged three times. 3 mL of a 2 mol / L K₂CO₃ aqueous solution and 12 mL of dioxane were added to the reaction flask, and the mixture was reacted at 95 °C for 2 days. Then, 0.5 mL of bromobenzene was added, and the reaction was continued for 1 day. After the reaction was complete, the mixture was cooled to room temperature, concentrated, and dissolved in dichloromethane. Ethanol was precipitated to obtain a solid. This solid (147 mg, 0.1 mmol), ACR₂ (1702 mg, 10 mmol), and TBHP (19 mg, 0.1 mmol) were placed in a 50 mL two-necked reaction flask and sealed. Nitrogen gas was purged three times. Chlorobenzene (10 mL) was 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 dichloromethane, precipitated with ethanol, purified by column chromatography, filtered, and dried to obtain the elastomer, which was the target product, with a yield of 77%.

[0062] The photoelectric and mechanical properties of the elastomer ACR2-Ar4 were tested, and the results are as follows: Figure 1 and Figure 2 As shown.

[0063] Example 5:

[0064] The main-chain conjugated intrinsically stretchable thermally delayed fluorescent elastomer involved in this embodiment is selected with Ar as Ar5, ACR as ACR2, R' as a C4 straight-chain alkyl group, and X as 0.2, i.e., elastomer ACR2-Ar5. The preparation process of the elastomer ACR2-Ar5 is as follows:

[0065]

[0066] Will (120mg, 0.2mmol), (218mg,0.5mmol), 3,6-dibromo-9-vinyl-9H-carbazole (105mg, 0.3mmol), TBAB (16mg, 0.05mmol), tetrakis(triphenylphosphine)palladium (57mg, 0.05mmol) were put into a 50mL two-necked flask and sealed, and the flask was replaced with nitrogen for three times. The flask was injected with 2mol / L aqueous solution of K2CO3(4mL), DMF (12mL), and reacted at 95℃ for 32 days, and then 0.5mL of bromobenzene was added and reacted for 1day. After the reaction was completed, the reaction solution was cooled to room temperature, concentrated, dissolved in THF, and precipitated with deionized water to obtain a solid; the solid (96mg, 0.1mmol), ACR2 (1161mg, 10mmol) and CHP (15mg, 0.1mmol) were put into a 50mL two-necked flask and sealed, and the flask was replaced with nitrogen for three times. The flask was injected with tetrahydrofuran (10mL), and reacted at 65℃ for 24h. After the reaction was completed and the reaction solution was cooled to room temperature, the solution was concentrated and dissolved in THF, precipitated with deionized water, and column chromatography was performed, and the elastomer obtained after filtration and drying was the target product, with a yield of 80%.

[0067] The photoelectric properties and mechanical properties of the elastomer ACR2-Ar5 were tested, and the results are shown in Figure 1 and Figure 2 .

[0068] Example 6:

[0069] This example relates to a main chain conjugated intrinsic stretchable thermally delayed fluorescent elastomer, which selects Ar as Ar6, ACR as ACR3, R' as a straight chain alkyl group of C3, and X as 0.2, i.e., the elastomer ACR3-Ar6. The preparation process of the elastomer ACR3-Ar6 is as follows:

[0070]

[0071] (130mg,0.12mmol), ​(218mg,0.5mmol), 3,6-dibromo-9-vinyl-9H-carbazole (105mg, 0.3mmol), TBAB (16mg, 0.05mmol), tetrakis(triphenylphosphine)palladium (57mg, 0.05mmol) were put into a 50mL two-necked flask and sealed, and the flask was replaced with nitrogen for three times. Aqueous solution of K2CO3 (4mL) with a concentration of 2mol / L, toluene (15mL) were injected into the flask, and the reaction was carried out at 95°C for 32 days, and then 0.5mL of bromobenzene was added and the reaction was carried out for 1 day. After the reaction was completed, the reaction solution was cooled to room temperature, concentrated, dissolved in THF, and precipitated in methanol to obtain a solid. The solid (102mg, 0.1mmol), ACR3 (1301mg, 10mmol) and BPO (24mg, 0.1mmol) were put into a 50mL two-necked flask and sealed, and the flask was replaced with nitrogen for three times. DMF (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, the solution was concentrated and dissolved in THF, and precipitated in methanol. After column chromatography, filtration and drying, the elastomer was obtained as the target product, and the yield was 88%.

[0072] The photoelectric properties and mechanical properties of the elastomer ACR3-Ar6 were tested, and the results are shown in Figure 1 and Figure 2 .

[0073] Example 7:

[0074] This example relates to a main-chain conjugated intrinsic stretchable thermally delayed fluorescent elastomer, which selects Ar as Ar7, ACR as ACR4, R' as a straight-chain alkyl of C2, and X as 0.3, i.e. the elastomer ACR4-Ar7. The preparation process of the elastomer ACR4-Ar7 is as follows:

[0075]

[0076] (240mg, 0.3mmol), (240mg, 0.3mmol), (218mg,0.5mmol), 3,6-dibromo-9-vinyl-9H-carbazole (700mg, 0.2mmol), TBAB (16mg, 0.05mmol), tetrakis(triphenylphosphine)palladium (57mg, 0.05mmol) were put into a 50mL two-necked flask and sealed, and the flask was replaced with nitrogen for three times. The flask was injected with 2mol / L aqueous solution of K2CO3(6mL), chlorobenzene (15mL), and reacted at 95℃ for 2 days, and then 0.5mL of bromobenzene was added and reacted for 1 day. After the reaction was completed, the reaction solution was cooled to room temperature, concentrated, dissolved in chloroform, and precipitated in methanol to obtain a solid; the solid (117mg, 0.1mmol), ACR4 (1572mg, 10mmol) and CHP (15mg, 0.1mmol) were put into a 50mL two-necked flask and sealed, and the flask was replaced with nitrogen for three times. The flask was injected with dioxane (10mL), and reacted at 65℃ for 24h. After the reaction was completed and the reaction solution was cooled to room temperature, the solution was concentrated and dissolved in chloroform, 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%.

[0077] The photoelectric properties and mechanical properties of the elastomer ACR4-Ar7 were tested, and the results are shown in Figure 1 and Figure 2 .

[0078] Example 8:

[0079] This example relates to a main-chain conjugated intrinsic stretchable thermally delayed fluorescent elastomer, which selects Ar as Ar8, ACR as ACR5, R' as a straight-chain alkyl group of C3, and X as 0.3, i.e., the elastomer ACR5-Ar8. The preparation process of the elastomer ACR5-Ar8 is as follows:

[0080]

[0081] (144mg,0.3mmol), (144mg,0.3mmol), 218 mg (0.5 mmol), 3,6-dibromo-9-vinyl-9H-carbazole (70 mg, 0.2 mmol), TBAB (16 mg, 0.05 mmol), and tetraphenylphosphine palladium (57 mg, 0.05 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 DMF (20 mL) were added to the reaction flask, and the reaction was carried out at 95 °C for 2 days. Then, 0.5 mL of bromobenzene was added, and the reaction was carried out for 1 day. After the reaction was completed, the mixture was cooled to room temperature, concentrated, and dissolved in the organic solvent dichloromethane. Methanol precipitated the solid. This solid (109 mg, 0.1 mmol), ACR5 (1151 mg, 10 mmol), and AIBN (16 mg, 0.1 mmol) were placed in a 50 mL two-necked reaction flask and sealed. Nitrogen gas was purged three times. 10 mL of chloroform was added to 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 THF, precipitated with methanol, purified by column chromatography, filtered, and dried to obtain the elastomer, which was the target product, with a yield of 89%.

[0082] The photoelectric and mechanical properties of elastomer ACR5-Ar8 were tested, and the results are as follows: Figure 1 and Figure 2 As shown.

[0083] Example 9:

[0084] The main-chain conjugated intrinsically stretchable thermally delayed fluorescent elastomer involved in this embodiment uses Ar9, ACR6, and R' as a C2 straight-chain alkyl group. When X is 0.4, it is elastomer ACR6-Ar9. The preparation process of elastomer ACR6-Ar9 is as follows:

[0085]

[0086] Will (2488mg, 0.4mmol), (218mg,0.5mmol), 3,6-dibromo-9-vinyl-9H-carbazole (35mg, 0.1mmol), TBAB (16mg, 0.05mmol), tetrakis(triphenylphosphine)palladium (57mg, 0.05mmol) were put into a 50mL two-necked flask and sealed, and the flask was replaced with nitrogen for three times. Aqueous solution of K2CO3 (4mL) with a concentration of 2mol / L, dioxane (12mL) were injected into the flask, and the reaction was carried out at 95°C for 2 days, and then 0.5mL of bromobenzene was added and the reaction was carried out for 1 day. After the reaction was completed, the reaction solution was cooled to room temperature, concentrated, dissolved in dichloromethane, and precipitated in ethanol to obtain a solid; the solid (104mg, 0.1mmol), ACR6 (1762mg, 10mmol) and ADN (25mg, 0.1mmol) were put into a 50mL two-necked flask and sealed, and the flask was replaced with nitrogen for three times. Toluene (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, the reaction solution was concentrated and dissolved in dichloromethane, precipitated in ethanol, and column chromatography was performed, and the elastomer obtained after filtration and drying was the target product, with a yield of 78%.

[0087] The photoelectric properties and mechanical properties of the elastomer ACR6-Ar9 were tested, and the results are shown in Figure 1 and Figure 2 .

[0088] Example 10:

[0089] This example relates to a main-chain conjugated intrinsic stretchable thermally delayed fluorescent elastomer, in which Ar is Ar10, ACR is ACR6, R' is a straight-chain alkyl group C3, and X is 0.4, i.e., the elastomer ACR6-Ar10. The preparation process of the elastomer ACR6-Ar10 is as follows:

[0090]

[0091] (260mg,0.4mmol), (260mg,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), Pd(TPP)4(57 mg, 0.05 mmol) were put into a 50 mL two-necked flask and sealed, and the flask was replaced with nitrogen for three times. Concentrated K2CO3 aqueous solution (4 mL) and chlorobenzene (10 mL) were injected into the flask, and the reaction was carried out at 95°C for 2 days, and then 0.5 mL of bromobenzene was added and the reaction was carried out for 1 day. After the reaction was completed, the reaction solution was cooled to room temperature, concentrated, dissolved in THF, and precipitated in methanol to obtain a solid; the solid (101 mg, 0.1 mmol), ACR6 (1902 mg, 10 mmol) and TBHP (19 mg, 0.1 mmol) were put into a 50 mL two-necked flask and sealed, and the flask was replaced with nitrogen 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, the solution was concentrated and dissolved in THF, and precipitated in methanol. After column chromatography, filtration and drying, the elastomer was obtained as the target product, and the yield was 76%.

[0092] The photoelectric properties and mechanical properties of the elastomer ACR6-Ar10 were tested, and the results are shown in Tables 1 and 2. Figure 1 and Figure 2 .

[0093] Example 11: Preparation of an OLED device

[0094] After the ITO glass was cleaned by ultrasonic wave, it was treated by oxygen plasma, and the sheet resistance of the ITO glass was 10 Ω / 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, ACR2-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.

[0095] The photoelectric properties of the OLED device were tested, and the results are shown in Tables 1 and 2. The maximum luminous brightness of the OLED device prepared based on the elastomer ACR6-Ar10 was 16111 cd / m 2 ; and the tensile rate of ACR-Ar6 could reach 400%.

[0096] Table 1. GPC and TGA tables of the elastomers of some examples of the present application

[0097]

[0098]

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

[0100]

[0101] The above are embodiments of the present inventor, it should be noted that the present application is not limited to these examples, these examples are only for better understanding of the present application, any equivalent transformation made according to the technical scheme of the present application, all belong to the protection scope of the present application.

Claims

1. A process for the preparation of a main-chain conjugated intrinsically stretchable thermal hysteresis elastomer, characterized in that, The preparation method comprises the following steps: in the first step, monomers and 3,6-dibromo-9-vinyl-9H-carbazole are used as raw materials to construct a conjugated rigid main chain; in the second step, a monomer corresponding to the ACR is used as an acrylic ester material to graft the conjugated rigid main chain, and a main-chain conjugated intrinsic stretchable thermal delayed fluorescence elastomer is prepared in an organic solvent, an additive and an initiator through a free radical polymerization mode, and the reaction equation is as follows: Wherein X represents the molar ratio of the component, and X < 0.5, Ar represents a conjugated structure; wherein the conjugated structure represented by Ar is selected from one or more of the following molecular structures: Wherein *, indicates the connection point; wherein the monomer corresponding to ACR is one of the following molecular structures: wherein R' is a linear or branched alkyl or alkoxy chain of 1 to 6 carbon atoms. 10 wherein R' is a linear or branched alkyl or alkoxy chain of 1 to 6 carbon atoms.

2. The method of making a main-chain conjugated intrinsically stretchable thermal delay fluorescent elastomer according to claim 1, characterized in that, The first step includes the following: (1) under nitrogen, monomers 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, cool to room temperature, concentrate the reaction liquid, and then dissolve it in a good solvent and precipitate the solid in a poor solvent; The second step includes the following: (3) Dissolve the solid obtained in (2) and the monomer corresponding to ACR in an organic solvent, add an additive and an initiator, and react at 65°C; (4) After the reaction is completed, extract, precipitate, filter, and dry to obtain the elastomer, which is the target product, main chain conjugated intrinsic stretchable thermal delayed fluorescence elastomer.

3. The method of making a main-chain conjugated intrinsically stretchable thermal delay fluorescent elastomer according to claim 1, characterized in that, In the first step, 0.1 mmol The monomer is dissolved in 10-20 mL of organic solvent, 0.05 mmol of additive is added, 0.05 mmol of initiator.

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

5. Use of a main-chain conjugated intrinsically stretchable thermally delayed fluorescent elastomer prepared according to the process of any one of claims 1 to 3, characterized in that, Such elastomers can be applied in the fields of flexible stretchable organic electroluminescent devices, electronic paper, organic photovoltaics, flexible energy storage, soft robots, or artificial intelligence.

Images