Synthesis method of degradable polystyrene material with multicolor fluorescence

Abstract

The invention discloses a synthetic method of a degradable polystyrene material with multicolor fluorescence. According to the method, a multi-color fluorescent polymer material with conventional luminescence property and aggregation-induced emission (AIE) property is obtained through cationic polymerization and Friedel-Crafts reaction, polymer materials with different fluorescence colors can be obtained by adjusting the reaction ratio of an active monomer to a catalyst and the reaction temperature, adjustable emission wavelength can be achieved, and the method is suitable for large-scale industrial production. And recycling can be realized through degradation. The synthesis method of the multi-color fluorescent degradable polystyrene material has the characteristics of simple operation, low synthesis cost, excellent material photophysical properties and the like, the obtained multi-color fluorescent polymer has conventional luminescence properties and AIE properties, the aggregation state fluorescence is enhanced, and the fluorescence intensity is enhanced. Good application prospects are realized in the fields of optical anti-counterfeiting, imaging marks, photoelectric elements and the like.

Description

Technical Field

[0001] The invention relates to the field of polymer synthesis, and in particular to a method for converting a one-step polymerization based on a cationic polymerization reaction and a Friedel-Crafts reaction into a polystyrene material having multicolor fluorescence and being degradable. Background Art

[0002] Traditional AIE (aggregation-induced emission) organic luminescent materials are generally small molecules containing large π conjugated systems, which have complex preparation procedures, poor biocompatibility, and are prone to environmental pollution. However, polymer fluorescent materials can better meet the needs of various application scenarios such as fluorescent dyes, biomedicine, imaging markers, optoelectronic components, and chemical sensors due to their adjustable chemical structure, more stable luminescence performance, and better mechanical and processing properties. However, polymer fluorescent materials still rarely show effective multi-color luminescence and high luminescence efficiency, and the luminescence mechanism and many scientific issues are waiting to be explored.

[0003] Cationic polymerization is a highly active polymerization reaction of carbon cationic active species initiated by proton acid or Lewis acid, and the reaction is fast and efficient; Friedel-Crafts reaction is a reaction catalyzed by Lewis acid and electrophilic substitution of halogen on aromatic ring. Based on cationic polymerization and Friedel-Crafts reaction, the present invention develops a method for synthesizing a polystyrene material with multicolor fluorescence and degradability. Summary of the invention

[0004] The fluorescent products currently available on the market have problems such as poor biocompatibility, high difficulty in preparation and environmental pollution, which limit their application. In order to solve the above problems, the purpose of the present invention is to provide a method for synthesizing a multicolor fluorescent polymer with simple steps, convenient operation, mild reaction conditions, low cost, excellent performance and recyclable.

[0005] The objective of the present invention is achieved in this way. The method for synthesizing a polystyrene material with multicolor fluorescence and being degradable is characterized in that styrene is used as a raw material and a Lewis acid is used as a catalyst to react in an organic solvent. Based on the cationic polymerization and Friedel-Crafts reaction mechanism of olefin compounds, a multicolor fluorescent polystyrene polymer is obtained in one step by controlling the reaction ratio and the reaction temperature. The polystyrene polymer material has AIE properties, a high quantum yield, and can be degraded and recycled.

[0006] Furthermore, the multicolor fluorescent polystyrene polymer is a multicolor fluorescent and degradable polystyrene polymer material, whose polymer chain contains a polystyrene main chain structure, has conventional luminescence properties and AIE properties, and by regulating the molar ratio of styrene monomer to catalyst and the reaction temperature, the multicolor fluorescent polystyrene polymer solid powder state is blue to yellow, and the multicolor fluorescent polystyrene polymer solution state is blue to cyan multicolor domain luminescence is achieved.

[0007] Furthermore, the specific steps are: adding styrene active monomer, Lewis acid catalyst and organic solvent into a reactor equipped with a magnetic stirrer, performing polymerization reaction at a certain temperature and nitrogen atmosphere, and performing post-treatment after a period of reaction time to obtain fluorescent polystyrene polymer material.

[0008] Furthermore, the Lewis acid catalyst is selected from anhydrous aluminum trichloride, anhydrous tin tetrachloride or anhydrous titanium tetrachloride, and its structural formula is:

[0009]

[0010] Further, the organic solvent is selected from dichloromethane, chloroform or carbon tetrachloride, and its structural formula is:

[0011]

[0012] Furthermore, the molar ratio of styrene active monomer, catalyst and organic solvent is 1:(0.01-1):(3-100), and the reaction temperature ranges from 0°C to the boiling point of the solvent.

[0013] Furthermore, the post-treatment step is to add excess deionized water to the reaction solution after the reaction is completed to quench the reaction, extract the organic phase with dichloromethane and wash it with deionized water, collect the organic phase, take an appropriate amount of anhydrous magnesium sulfate to dry the organic phase, filter and collect the organic phase, concentrate it to obtain a crude product, drop it into a poor solvent, and obtain a polymer by precipitation method.

[0014] Furthermore, the poor solvent in the precipitation method is selected as methanol, and the organic solvent dichloromethane is selected as the good solvent, and the volume ratio of the good solvent to the poor solvent is 1:(20-30).

[0015] The degradation application of a polystyrene-like material having multicolor fluorescence and being degradable synthesized by the above-mentioned synthesis method of the present invention is characterized in that the polystyrene-like material having multicolor fluorescence and being degradable synthesized by the above-mentioned synthesis method, anhydrous aluminum chloride and an organic solvent toluene are added into a reactor with a magnetic stirrer in a mass ratio of 1:1:35, reacted for 5 hours in a nitrogen atmosphere at 100°C, and after post-treatment, analysis of the reaction liquid components shows that the polystyrene-like material having multicolor fluorescence and being degradable is degraded into benzene.

[0016] The application of a polystyrene-like material having multicolor fluorescence and being degradable synthesized by the above-mentioned synthesis method of the present invention is characterized in that the polystyrene-like material having multicolor fluorescence and being degradable synthesized by the above-mentioned synthesis method is blended with a variety of original plastic media, and further processed to obtain a fluorescent product for use as a fabric marker.

[0017] Specifically, the technical method steps provided by the present invention are as follows:

[0018] Step 1: Purify the crude styrene on a vacuum distillation apparatus in a nitrogen atmosphere to obtain a refined styrene monomer, which is stored frozen in a nitrogen atmosphere. Under the conditions of dehydration and deoxygenation, add the active monomer styrene, catalyst and organic solvent to a reaction tube equipped with a magnetic stirrer, and perform polymerization at a certain temperature. After a period of time, add excess deionized water to the reaction solution to quench the reaction, extract the organic phase with dichloromethane and wash it three times with excess water, collect the organic phase, take an appropriate amount of anhydrous magnesium sulfate to dry the organic phase, filter and collect the organic phase and concentrate to obtain a crude product. The crude product is dripped into a poor solvent drop by drop, and a polymer material is obtained by precipitation.

[0019] Among them, the active monomer styrene structural formula is:

[0020]

[0021] Among them, the catalyst (including anhydrous aluminum trichloride, anhydrous tin tetrachloride, anhydrous titanium tetrachloride and other Lewis acids that can be used for cationic polymerization and Friedel-Crafts reaction) has the structural formula:

[0022]

[0023] Among them, the organic solvent (including pure solvents and mixed solvents of chlorine-containing compounds such as dichloromethane, chloroform, carbon tetrachloride, etc.) has the structural formula:

[0024]

[0025] Optionally, the method of removing water and oxygen is to use a vacuum pump to remove oxygen, and at the same time use a hot air gun to heat and blow to remove water in the reaction tube, and after the reaction tube is cooled, high-purity nitrogen is introduced for replacement, and this process is repeated three times.

[0026] Optionally, the organic solvent is dichloromethane.

[0027] Optionally, the molar ratio of the active monomer styrene, the catalyst and dichloromethane is 1:(0.01-1):(3-100).

[0028] Optionally, the reaction temperature is from 0°C to the boiling point of the solvent.

[0029] Alternatively, the anhydrous magnesium sulfate used to dry the organic phase may be carried out using other inorganic water-absorbing desiccants.

[0030] Optionally, concentration to obtain a crude product is performed using a rotary evaporator.

[0031] Furthermore, the novel polymer material generated by the synthesis method of a biodegradable polystyrene-based polymer with multicolor fluorescence described in the present invention has luminescence properties, and its fluorescence changes with the reaction molar ratio of the active monomer styrene to the catalyst and the reaction temperature, and exhibits different fluorescence colors from blue to yellow under irradiation with a 365nm lamp. Most polymer materials have fluorescence emission in the range of 430 to 557nm in the solid state under the maximum excitation wavelength of 380nm; the fluorescence in the solution state is concentration-dependent, and is mostly emitted in the range of 433 to 495nm under the maximum excitation wavelength of 380nm.

[0032] Furthermore, the method for synthesizing the polystyrene-based material having multicolor fluorescence and being degradable described in the present invention can generate a fluorescent material having a high quantum yield, which can be as high as 91% in a solid state.

[0033] In order to improve the reaction efficiency, the preparation method of the present invention preferably further includes: before the polymerization reaction, dehydrating and deoxygenating the reaction system. The present invention has no particular limitation on the dehydrating and deoxygenating method, which can be a conventional dehydrating and deoxygenating method in the art, such as vacuum drying, replacement with inert gas, and the like.

[0034] The present invention is based on the cationic polymerization of styrene, discovers the multicolor fluorescence characteristics of the product by changing the reaction conditions, and obtains a series of multicolor polymer fluorescent materials with high quantum yield by connecting the alkyl group in the alkyl halide to the aromatic group of the polystyrene side chain. The present invention is a new strategy for the application of polystyrene-based functional polymers.

[0035] The present invention has the following beneficial effects:

[0036] 1. The present invention relates to a method for synthesizing a polystyrene-based material polymer having multicolor fluorescence and being degradable based on cationic polymerization and Friedel-Crafts reaction, which has the advantages of mild reaction conditions, simple steps, convenient operation, and low cost.

[0037] 2. The new material provided by the present invention has luminescent properties, and the fluorescence color can be controlled by adjusting the reaction molar ratio of the active monomer styrene and the catalyst and the reaction temperature. The change from blue light to yellow light can be achieved in the solid state, and the change from blue light to cyan light can be achieved in the solution state. At the same time, the new fluorescent material provided by the present invention has ultra-high quantum yield in both the solid state and the solution state.

[0038] 3. The novel material provided by the present invention has degradable and recyclable properties, and chemical monomers with new uses can be obtained through a simple chemical recycling method.

[0039] 4. The polystyrene-based polymer with multicolor fluorescence and degradable properties provided by the present invention can be used in the preparation of fluorescent labeling, patterning, display, and optoelectronic components such as LEDs and OLEDs due to its ultra-high quantum yield in the aggregated state. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] The specific implementation modes of the present invention are further described in detail below with reference to the accompanying drawings.

[0041] Figure 1 is the hydrogen nuclear magnetic resonance spectrum of the polymer in Example 1.

[0042] Figure 2 This is the blue fluorescence curve of the polymer obtained by catalyzing the polymerization of styrene by anhydrous aluminum chloride in Example 1.

[0043] Figure 3 This is the quantum yield spectrum of the cyan fluorescent polymer obtained by catalyzing the polymerization of styrene with anhydrous aluminum chloride in Example 2.

[0044] Figure 4 The fluorescence spectrum curves of fluorescent materials of different colors obtained by controlling the polymerization reaction of active monomer styrene with different equivalents of catalyst anhydrous aluminum chloride in Example 1 are shown.

[0045] Figure 5 This is a photograph of a fluorescent film product obtained by blending the multicolor fluorescent and degradable styrene material prepared in Example 1 with virgin polymethyl methacrylate pellets in Example 4. DETAILED DESCRIPTION

[0046] The following provides drawings and specific embodiments to describe the present invention in detail. The following specific implementation methods are only used to explain the present invention, and the protection scope is not limited by the following embodiments.

[0047] The experimental data in the examples were measured using the following instruments and measurement methods:

[0048] (1) Method for determining the chemical structure of the generated polymer: using nuclear magnetic resonance spectroscopy;

[0049] (2) Method for determining the fluorescence properties of the generated polymer: using a fluorescence spectrometer.

[0050] Embodiment 1:

[0051] This embodiment provides a method for preparing a fluorescent polymer by catalyzing styrene monomer with anhydrous aluminum chloride.

[0052] The chemical reaction formula of the active monomer styrene and the catalyst anhydrous aluminum chloride used in this example is as follows:

[0053]

[0054] This embodiment includes the following steps:

[0055] (1) Place anhydrous aluminum chloride (0.02 eq, 0.05 g) as a polymerization catalyst and a magnetic stirrer in a dry reaction tube, repeat vacuuming, hot-blowing, cooling, and then passing nitrogen three times to remove water and oxygen;

[0056] (2) Add organic solvent dichloromethane (3.25 eq, 2 mL) into a reaction tube under nitrogen atmosphere;

[0057] (3) Place the reaction tube in a 5°C ice water bath and stir. Slowly add 1 g of styrene monomer into the reaction system.

[0058] (4) After reacting for 24 hours, excess deionized water was added to the reaction solution to quench the reaction, and the organic phase was extracted with dichloromethane and washed three times with deionized water. The organic phase was collected by filtration and concentrated to obtain a crude product.

[0059] (5) The crude product was added dropwise into methanol at a volume ratio of good solvent (dichloromethane) to poor solvent (methanol) of 1:(20-30), and the product (a degradable styrene-based material with multicolor fluorescence) was obtained by precipitation method with a yield of 95%. The product emitted deep blue fluorescence and had AIE properties, and the solid state quantum yield was as high as 76%. Figure 1 This is the hydrogen nuclear magnetic resonance spectrum of the polymer (product) in Example 1. Figure 2 This is the blue fluorescence curve of the polymer (product) obtained by polymerization of styrene catalyzed by anhydrous aluminum chloride in Example 1. Figure 4 The fluorescence spectrum curves of fluorescent materials (products) of different colors obtained by controlling the polymerization reaction of active monomer styrene with different equivalents of catalyst anhydrous aluminum chloride in Example 1.

[0060] Embodiment 2:

[0061] This embodiment provides a method for preparing a fluorescent polymer by catalyzing styrene monomer with anhydrous aluminum chloride.

[0062] The chemical reaction formula of the active monomer styrene and the catalyst anhydrous aluminum chloride used in this example is as follows:

[0063]

[0064] This embodiment includes the following steps:

[0065] (1) Place anhydrous aluminum chloride (0.1 eq, 0.25 g) as a polymerization catalyst and a magnetic stirrer in a dry reaction tube, repeat vacuuming, hot blowing, cooling, and then passing nitrogen three times to remove water and oxygen;

[0066] (2) Add organic solvent dichloromethane (3.25 eq, 2 mL) into a reaction tube under nitrogen atmosphere;

[0067] (3) Place the reaction tube in a 25°C oil bath and stir. Slowly add 1 g of styrene monomer into the reaction system.

[0068] (4) After reacting for 24 hours, excess deionized water was added to the reaction solution to quench the reaction, and the organic phase was extracted with dichloromethane and washed three times with deionized water. The organic phase was collected by filtration, and an appropriate amount of anhydrous magnesium sulfate was added to dry the organic phase. The organic phase was collected by filtration and concentrated to obtain a crude product.

[0069] (5) The crude product was added dropwise into methanol at a volume ratio of good solvent (dichloromethane) to poor solvent (methanol) of 1:(20-30), and the product was obtained by precipitation method with a yield of 63%. The product emitted cyan-blue fluorescence and had AIE properties, and the solid state quantum yield was as high as 91%. Figure 3 This is the quantum yield spectrum of the cyan fluorescent polymer (product) obtained by polymerization of styrene catalyzed by anhydrous aluminum chloride in Example 2.

[0070] Embodiment 3:

[0071] This embodiment provides a method for degrading the degradable styrene material having multi-color fluorescence obtained in Embodiment 1 into benzene monomer.

[0072] The degradation reaction formula of the fluorescent polymer material provided in this embodiment is shown below:

[0073]

[0074] This embodiment includes the following steps:

[0075] (1) Weigh 150 mg of the polychromatic fluorescent and degradable styrene-based material prepared in Example 1 and 150 mg of anhydrous aluminum chloride in a dry reaction tube equipped with a magnetic stirrer;

[0076] (2) Connect the reaction tube to a nitrogen atmosphere and purge repeatedly for 10 minutes;

[0077] (3) Add 6 mL of toluene and place the reaction tube in a 100°C oil bath and stir.

[0078] (4) After reacting for 5 hours, an excess of deionized water was added to the reaction solution to quench the reaction, and the organic phase was separated. The yield of benzene was calculated by nuclear magnetic resonance spectrometry and gas chromatography-mass spectrometry.

[0079] Embodiment 4:

[0080] This embodiment provides a method for obtaining a fluorescent film product by blending the multi-color fluorescent and degradable styrene material prepared in Example 1 with virgin polymethyl methacrylate pellets.

[0081] This embodiment includes the following steps:

[0082] (1) Weigh 50 mg of the multicolor fluorescent and degradable styrene material prepared in Example 1 and 950 mg of polymethyl methacrylate pellets respectively into a dry reaction tube equipped with a magnetic stirrer, and add 5 mL of tetrahydrofuran;

[0083] (2) Place the reaction tube in a 60°C oil bath and stir for 10 min;

[0084] (3) The uniformly mixed solution was added into a mold, dried in a vacuum drying oven at 40° C. for 10 h, and demolded to obtain a fluorescent film product.

Claims

1. A method for synthesizing a polystyrene material having multicolor fluorescence and being degradable, characterized in that: Using styrene as raw material and Lewis acid as catalyst, the reaction is carried out in an organic solvent. Based on the cationic polymerization of olefin compounds and the Friedel-Crafts reaction mechanism, by controlling the reaction ratio and reaction temperature, a multicolor fluorescent polystyrene polymer is obtained in one step. The polystyrene polymer material has AIE properties, high quantum yield, and can be degraded and recycled.

2. The method for synthesizing a polystyrene material having multicolor fluorescence and being degradable according to claim 1, characterized in that: The multicolor fluorescent polystyrene polymer is a multicolor fluorescent and degradable polystyrene polymer material, whose polymer chain contains a polystyrene main chain structure, has conventional luminescence properties and AIE properties, and by regulating the molar ratio of styrene monomer to catalyst and the reaction temperature, the multicolor fluorescent polystyrene polymer solid powder state is blue to yellow, and the multicolor fluorescent polystyrene polymer solution state is blue to cyan multicolor domain luminescence is achieved.

3. The method for synthesizing a polystyrene material having multicolor fluorescence and being degradable according to claim 1, characterized in that: The specific steps are: adding styrene active monomer, Lewis acid catalyst and organic solvent into a reactor equipped with a magnetic stirrer, carrying out polymerization reaction at a certain temperature and nitrogen atmosphere, and after a period of reaction time, post-processing to obtain fluorescent polystyrene polymer material.

4. The method for synthesizing a polystyrene material having multicolor fluorescence and being degradable according to claim 1, characterized in that: The Lewis acid catalyst is selected from anhydrous aluminum trichloride, anhydrous tin tetrachloride or anhydrous titanium tetrachloride, and its structural formula is: 。 5. The method for synthesizing a polystyrene material having multicolor fluorescence and being degradable according to claim 1, characterized in that: The organic solvent is selected from dichloromethane, chloroform or carbon tetrachloride, and its structural formula is: 。 6. The method for synthesizing a polystyrene material having multicolor fluorescence and being degradable according to claim 3, characterized in that: The molar ratio of styrene active monomer, catalyst and organic solvent is 1:(0.01~1):(3~100), and the reaction temperature range is 0 o C~boiling point of solvent.

7. The method for synthesizing a polystyrene material having multicolor fluorescence and being degradable according to claim 3, characterized in that: The post-treatment steps are as follows: after the reaction is completed, excess deionized water is added to the reaction solution to quench the reaction, the organic phase is extracted with dichloromethane and washed with deionized water, the organic phase is collected, an appropriate amount of anhydrous magnesium sulfate is taken to dry the organic phase, the organic phase is collected by filtration and concentrated to obtain a crude product, the crude product is dropped into a poor solvent, and a polymer is obtained by precipitation method.

8. The method for synthesizing a polystyrene material having multicolor fluorescence and being degradable according to claim 7, characterized in that: The poor solvent in the precipitation method is methanol, and the organic solvent dichloromethane is the good solvent. The volume ratio of the good solvent to the poor solvent is 1:(20~30).

9. A degradation application of a polystyrene material having multicolor fluorescence and being degradable synthesized by the synthesis method according to any one of claims 1 to 8, characterized in that: A polystyrene material having multicolor fluorescence and being degradable synthesized by the synthesis method according to any one of claims 1 to 8, anhydrous aluminum chloride and an organic solvent toluene are added into a reactor with a magnetic stirrer in a mass ratio of 1:1:35, and heated at 100 o C in a nitrogen atmosphere for 5 h. After post-treatment, analysis of the reaction liquid components showed that the polychromatic fluorescent and degradable styrene materials were all degraded into benzene.

10. Use of a polystyrene material having multicolor fluorescence and being degradable synthesized according to any one of the synthesis methods of claims 1 to 8, characterized in that: A polystyrene material with multi-color fluorescence and being degradable synthesized by the synthesis method described in any one of claims 1 to 8 is blended with a variety of virgin plastic media and further processed to obtain a fluorescent product for use as a fabric marker.

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