Preparation method of stretchable organic polymer room temperature phosphorescent elastomer

Abstract

The invention provides a stretchable room-temperature phosphorescent polymer elastomer, the chemical structural formula of the elastomer is as shown in formula (I): # imgabs0 #, the elastomer is composed of a phosphorescent vinyl monomer, a hard-segment vinyl monomer, a soft-segment vinyl monomer, a 2-ureido-4-pyrimidone monomer and the like, and the phosphorescent monomer part provides efficient phosphorescent emission; the hard-segment monomer part provides certain mechanical strength for the elastomer, the soft-segment monomer part provides tensile property, and UPy provides multiple hydrogen bonds to form a cross-linked network to fix triplet excitons, so that the phosphorescence service life is prolonged. The obtained elastomer has the luminescent characteristics of blue fluorescence and green phosphorescence, and has a relatively long afterglow luminescent characteristic, the afterglow lasting time reaches more than 6 seconds, in addition, the elastomer also has good mechanical properties, the tensile property reaches 350%, and the Young modulus reaches more than 10 MPa. Therefore, the invention provides a simple and efficient method for preparing the organic polymer room-temperature phosphorescent elastomer, and the material has wide prospects in the fields of three-dimensional anti-counterfeiting and flexible optoelectronic devices and the like.

Description

Technical Field

[0001] The present invention relates to the field of organic synthesis, and particularly to a method for preparing a stretchable polymer elastomer containing a phosphorescent emitting unit. Background Art

[0002] Organic polymer room temperature phosphorescent materials have the characteristics of long lifetime, large-area processability, excellent flexibility, etc., and have broad application prospects in the fields of wearable optoelectronic devices, flexible displays, high-energy radiation visualizers, advanced anti-counterfeiting, etc. The generation of phosphorescence includes two processes: intersystem crossing from the singlet excited state to the triplet state and radiative transition from the triplet excited state to the ground state. However, the weak spin-orbit coupling and large non-radiative rate constant of organic materials make the triplet emission of the excited state easily quenched, so it is still relatively difficult to achieve room temperature phosphorescent emission of organic materials. In recent years, many strategies have been developed by scientific researchers to achieve room temperature phosphorescent emission of organic materials, including methods such as introducing heavy atoms, heteroatoms, and carbonyl groups to enhance spin-orbit coupling and improve intersystem crossing from the singlet state to the triplet state, and introducing rigid matrices such as crystal engineering and polymer doping to stabilize triplet excitons and reduce non-radiative transitions. However, crystal growth requires harsh growth conditions and is not easy to process, and polymer doping has disadvantages such as phase separation. And currently reported organic room temperature phosphorescent materials still have relatively poor mechanical properties. Therefore, there is an urgent need to develop a simple and efficient method to achieve organic room temperature phosphorescent materials with excellent mechanical processing properties. Summary of the Invention

[0003] The purpose of the present invention is to provide a simple and efficient method for preparing a stretchable organic polymer room temperature phosphorescent elastomer.

[0004] To achieve the purpose of the present invention, a phosphorescent emitting molecule, a hard microdomain structure, a soft microdomain, and a vinyl compound of a fixed matrix are mixed, and then the required stretchable polymer room temperature phosphorescent elastomer is obtained by in-situ photopolymerization. 2-Ureido-4-pyrimidinone (UPy) is used as the fixed matrix, and the multiple hydrogen bonds of UPy generate a rigid environment that can inhibit the non-radiative transition of triplet excitons and can isolate water, oxygen, etc. Monomers such as methyl methacrylate and acrylic acid are used as the hard segment region of the polymer to provide a certain strength, and hydroxyethyl acrylate, butyl hexafluoracrylate, etc. are used as the soft segment region of the polymer to provide good stretchability.

[0005] The structural formula of the stretchable room temperature phosphorescent polymer elastomer provided by the present invention is as follows:

[0006]

[0007] Among them, n and m in the above molecular structural formula are natural numbers, preferably 2 ≤ n ≤ 10;

[0008] In the above molecular structural formula, p, x, y, and z are feed ratios, preferably 0.001 ≤ p ≤ 0.1, 10 ≤ x ≤ 500, 10 ≤ y ≤ 1000, 0.1 ≤ p ≤ 1;

[0009] P of the above phosphorescent monomer can be the following molecules CDF, CzPy or CzPT, and the specific structural formulas are as follows:

[0010]

[0011] The vinyl molecule G of the above hard segment can be acrylic acid (-OH), methyl acrylate (-CH3), acrylamide (-NH2);

[0012] The vinyl molecule R of the above soft segment can be acrylate, where R is -C n H 2n+1 , n is a natural number, preferably 4 ≤ n ≤ 18, and it can also be 2-hydroxyethyl acrylate where R is or 2,2,3,4,4,4-hexafluorobutyl ester;

[0013] The present invention also provides a preparation method of the above elastomer, including the following steps:

[0014] Mix the phosphorescent monomer, UPy, soft segment monomer, hard segment monomer and photoinitiator, etc. in a solvent, ultrasonically homogenize, slowly volatilize the solvent, and then irradiate with ultraviolet light in a mold of a specific size for a certain time to obtain a polymer elastomer. The specific synthesis route is as follows:

[0015]

[0016] In the preparation method of the above elastomer, the reaction solvent can be dichloromethane, chloroform, or it can also be tetrahydrofuran, etc.;

[0017] The photoinitiator in the above synthesis route can be Irg651, Irg819, Irg725, Irg2959, etc.;

[0018] The UV irradiation time in the above synthesis step can be 10 - 60 minutes;

[0019] The size of the above mold can be customized according to the actual needs of the application, and it can be 10 - 60 mm in length, 1 - 6 mm in width, and 0.5 - 3 mm in height.

[0020] The present invention designs a class of phosphorescent elastomers, which are obtained by a one-step photopolymerization of phosphorescent monomers, hard segments, soft segments and rigid matrices. By adjusting the different ratios of each component, the luminescent properties and mechanical properties of the elastomer are adjusted to achieve an elastomer with excellent phosphorescent properties and mechanical properties. Specific examples

[0021] To better understand the content of this invention patent, the following specific examples are used to illustrate the synthesis method of the polymer phosphorescent elastomer. Specifically, it includes the monomer ratios and preparation conditions selected, etc., but these examples do not limit the present invention.

[0022] Example 1:

[0023] An organic polymer room temperature phosphorescent elastomer, its specific structural formula is as follows:

[0024]

[0025] The preparation method is as follows:

[0026]

[0027] Weigh the phosphorescent monomer CDF (0.0030 g, 0.0063 mmol), UPy (0.0818 g, 0.2 mmol) and dissolve them in dichloromethane solvent. Slowly evaporate the solvent in a vacuum drying oven at 35 °C. Then add MMA (1.001 g, 10 mmol), HEA (1.161 g, 10 mmol), and photoinitiator 2959 (0.1345 g, 0.6 mmol). Ultrasonic for 30 min to make them completely mixed. Then pour the mixed mixture into a silica gel mold (40 * 5 * 2 mm) and irradiate it with 365 nm ultraviolet light for 30 minutes to obtain the desired polymer elastomer.

[0028] Example 2:

[0029] An organic polymer room temperature phosphorescent elastomer, its specific structural formula is as follows:

[0030]

[0031] The preparation method is as follows:

[0032]

[0033] Weigh the phosphorescent monomer CzPy (0.0032 g, 0.008 mmol), UPy (0.0818 g, 0.2 mmol), and dissolve them in tetrahydrofuran solvent. Slowly evaporate the solvent in a vacuum drying oven at 35 °C. Then add MMA (0.5006 g, 5 mmol), HEA (0.8128 g, 7 mmol), and photoinitiator 2959 (0.076 g, 0.33 mmol). Ultrasonic for 50 min to make them completely mixed. Then pour it into a silica gel mold (40 * 5 * 1 mm) and irradiate it with 365 nm ultraviolet light for 40 minutes to obtain the desired polymer elastomer.

[0034] Example 3:

[0035] An organic polymer room-temperature phosphorescent elastomer, and its specific structural formula is as follows:

[0036]

[0037] The preparation method is as follows:

[0038]

[0039] Weigh the phosphorescent monomer CDF (0.0030 g, 0.0063 mmol) and UPy (0.0205 g, 0.05 mmol), dissolve them in dichloromethane solvent, slowly evaporate the solvent in a vacuum drying oven at 35 °C, then add AA (0.216 g, 3 mmol), HEA (0.4645 g, 4 mmol), HFBA (0.7083 g, 3 mmol) and photoinitiator 651 (0.1281 g, 0.5 mmol), ultrasonicate for 50 min to make them completely mixed, and then pour it into a silica gel mold (20*5*2 mm), irradiate it with 365 nm ultraviolet light for 20 minutes to obtain the desired polymer elastomer.

[0040] Example 4:

[0041] An organic polymer room-temperature phosphorescent elastomer, and its specific structural formula is as follows:

[0042]

[0043] The preparation method is as follows:

[0044]

[0045] Weigh the phosphorescent monomer CDF (0.0030 g, 0.0063 mmol) and UPy (0.0205 g, 0.05 mmol), dissolve them in dichloromethane solvent, slowly evaporate the solvent in a vacuum drying oven at 35 °C, then add AA (0.2880 g, 4 mmol), HEA (0.4645 g, 4 mmol), HFBA (0.7083 g, 3 mmol) and photoinitiator 651 (0.1281 g, 0.5 mmol), ultrasonicate for 50 min to make them completely mixed, and then pour it into a silica gel mold (20*5*2 mm), irradiate it with 365 nm ultraviolet light for 20 minutes to obtain the desired polymer elastomer.

[0046] The above-described embodiments merely represent several implementation manners of the present invention. Their descriptions are relatively specific and detailed, but they should not be construed as limiting the scope of the patent of the present invention. It should be noted that for those of ordinary skill in the art, without departing from the concept of the present invention, several modifications and improvements can still be made, and these all fall within the protection scope of the present invention. Therefore, the protection scope of the patent of the present invention shall be subject to the appended claims. Description of the Drawings

[0048] Figure 1 It is the FT-IR spectrum of the polymer elastomer in Example 1 of the present invention. The formation of the hydrogen bond region on the infrared spectrum indicates the successful synthesis of the elastomer.

[0049] Figure 2 It is the fluorescence emission spectrum of the polymer elastomer in Example 1 of the present invention, and its maximum emission wavelength is located at 410 nm.

[0050] Figure 3 It is the phosphorescence emission spectrum of the polymer elastomer in Example 1 of the present invention, and its maximum emission wavelength is located at 530 nm.

[0051] Figure 4 It is the afterglow photo of the polymer elastomer in Example 1 of the present invention. After stopping the ultraviolet light irradiation, its afterglow duration reaches 6 seconds.

[0052] Figure 5 It is the stress-strain curve in Example 3 of the present invention, and its maximum elongation rate reaches 350%, and the Young's modulus reaches more than 3.9 MPa.

[0053] Figure 6 It is the stress-strain curve in Example 4 of the present invention. The Young's modulus reaches more than 15 MPa, and its maximum elongation rate reaches 175%.

Claims

1. A stretchable organic polymer room temperature phosphorescent elastomer, characterized in that, The chemical formula of the elastomer is shown in Formula (I): Among them, n and m in the above molecular structural formula are natural numbers, preferably 2 ≤ n ≤ 10; p, x, y, z in the above molecular structural formula are feed ratios, preferably 0.001 ≤ p ≤ 0.1, 10 ≤ x ≤ 500, 10 ≤ y ≤ 1000, 0.1 ≤ p ≤ 1; P of the above phosphorescent monomer can be the following molecules CDF, CzPy or CzPT, and the specific structural formulas are as follows: The vinyl molecules of the above hard segment G can be acrylic acid (-OH), methyl acrylate (-CH3) or acrylamide (-NH2); The vinyl molecule R of the above soft segment can be acrylate, where R is -C n H 2n+1 , n is a natural number, preferably 4 ≤ n ≤ 18, and it can also be 2-hydroxyethyl acrylate where R is or 2,2,3,4,4,4-hexafluorobutyl acrylate.

2. The preparation method of the above-mentioned phosphorescent elastomer, characterized in that, It includes the following steps: Mix the phosphorescent monomer and UPy in a solvent, slowly volatilize the solvent, then add the soft segment monomer, hard segment monomer and photoinitiator and mix evenly by ultrasound, and then irradiate with ultraviolet light in a mold of a specific size for a certain time to obtain a polymer elastomer. The specific synthesis route is as follows: 。 3. The preparation method according to claim 2, characterized in that, In the preparation method of the elastomer, the reaction solvent can be dichloromethane, chloroform, ethyl acetate, or tetrahydrofuran, etc.

4. The preparation method according to claim 2, characterized in that, In the preparation method of the elastomer, the photoinitiator can be Irg651, Irg819, Irg725, Irg2959, etc.

5. In the preparation method of the elastomer, the UV irradiation time can be 10 - 60 minutes.

6. In the preparation method of the elastomer, the size of the mold can be customized according to the actual needs of the application, and it can be 10 - 60 mm in length, 1 - 6 mm in width, and 0.5 - 3 mm in height.

7. The above polymer elastomer exhibits excellent fluorescence emission characteristics, and the fluorescence emission wavelength is in the blue light region.

8. The above polymer elastomer exhibits excellent phosphorescence emission characteristics, and the phosphorescence emission is green light emission, with a large Stokes shift.

9. The above polymer elastomer has a long persistent fluorescence emission characteristic, and the afterglow duration reaches more than 6 seconds.

10. The above polymer elastomer has good mechanical properties, the tensile property reaches 350%, and the Young's modulus reaches more than 15 MPa.

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