A kind of β-aldehyde polysulfide and its preparation method and application

Abstract

The present invention belongs to the technical field of polymer synthesis, and discloses a β-formaldehyde polythioether and a preparation method and application thereof. The β-formaldehyde polythioether has a general structural formula shown in formula (I), wherein n is an integer of 2 to 200, R 1 , R 2 The preparation method is as follows: in an inert or air atmosphere, a dibasic acetylene aldehyde compound and a dibasic thiol compound are polymerized in an organic solvent to obtain a β-aldehyde polysulfide. The present invention designs and synthesizes an acetylene aldehyde monomer, and the high reactivity of the monomer enables it to polymerize with a thiol compound under non-catalytic conditions. The method is simple and efficient, and can synthesize a polymer with a high molecular weight, good thermal stability, and a high refractive index. The obtained polysulfide contains an aldehyde side chain, which not only realizes the selective detection and high-sensitivity detection of hydrazine, but also can expand the structure and function of the polymer through post-modification. #imgabs0#

Description

Technical Field

[0001] The invention belongs to the technical field of polymer synthesis, and specifically relates to a beta-aldehyde polythioether and a preparation method and application thereof. Background Art

[0002] The development and establishment of new polymerization methodologies are of great significance for the construction of polymer materials with unique structures and advanced functions. In the field of polymer synthesis, thiol-alkyne click polymerization has become an important method for the preparation of sulfur-containing functional materials, and a variety of free radical-initiated, base-mediated, and metal-catalyzed thiol-alkyne polymerizations have been developed. It should be noted that the reactivity of ordinary alkynyl groups is low, and most of the above polymerization reactions require ultraviolet irradiation, high temperature, and metal catalysts, which to a certain extent limits their wide application.

[0003] In order to improve the reactivity of the alkyne group, researchers at home and abroad have tried to conjugate it with electron-withdrawing groups such as carbonyl, ester, trifluoromethyl, etc., and designed and synthesized a variety of single / double activated alkynes. Although the polymerization of activated alkynes and thiol compounds gives the products more diverse structures and functions, there are also many problems. For example, the preparation conditions of carbonyl activated alkynes are relatively harsh, some polymerizations still require bases as catalysts, and most of the products obtained by activated alkyne polymerization can only achieve post-modification of terminal groups, resulting in low structural regulation and derivatization freedom. Based on this, it is of great significance to develop efficient, convenient, economical and environmentally friendly green polymerization of activated alkyne-thiol groups under catalyst-free conditions to prepare polysulfide with high structural derivatization, and to enrich polymer structures and develop high-tech applications. Summary of the invention

[0004] In view of the shortcomings and deficiencies of the above prior art, the primary purpose of the present invention is to provide a β-aldehyde polysulfide.

[0005] Another object of the present invention is to provide a method for preparing the above-mentioned β-aldehyde polysulfide.

[0006] Another object of the present invention is to provide the use of the above-mentioned β-aldehyde polysulfide in detecting hydrazine.

[0007] Another object of the present invention is to provide a post-modification application of the above-mentioned β-aldehyde polythioether.

[0008] The purpose of the present invention is achieved through the following technical solutions:

[0009] A β-formaldehyde polysulfide having the general structural formula shown in formula (I):

[0010]

[0011] Wherein, n is an integer from 2 to 200, R 1 , R 2are the same or different organic groups.

[0012] Furthermore, the R 1 is any one of the following chemical structural formulas (1) to (8), wherein R 2 Any one of the following chemical structural formulas (9) to (16):

[0013]

[0014] Wherein, m and h are integers of 1 to 15; X is a C, O or S element, and * indicates a substitution position.

[0015] The preparation method of the above-mentioned β-aldehyde polysulfide comprises the following preparation steps:

[0016] Under an inert atmosphere or air, a dibasic acetylenic aldehyde compound of formula (II) and a dibasic thiol compound of formula (III) are polymerized in an organic solvent, and the product is separated to obtain a β-aldehyde polysulfide;

[0017]

[0018] Furthermore, the organic solvent is one or a mixture of two or more of tetrahydrofuran, toluene, 1,4-dioxane, dimethyl sulfoxide, N,N-dimethylformamide, dimethylacetamide, and chloroform; preferably N,N-dimethylformamide.

[0019] Furthermore, the polymerization reaction temperature is 20 to 80° C., and the reaction time is 1 to 6 hours.

[0020] Furthermore, the molar ratio of the dibasic acetylenic aldehyde compound to the dibasic thiol compound is 1:(1-1.1).

[0021] Furthermore, the concentration of the dibasic acetylenic aldehyde compound in the organic solvent is 0.05 to 0.5 mol / L, preferably 0.2 to 0.3 mol / L.

[0022] Furthermore, the method for separating the product is as follows: after the reaction is completed, the product is dissolved in a solvent, then added into n-hexane for precipitation, the precipitate is collected, and dried to constant weight to obtain β-aldehyde polysulfide.

[0023] The above-mentioned β-aldehyde polysulfide is used in the detection of hydrazine.

[0024] Post-modification application of the above β-aldehyde polythioether.

[0025] Furthermore, the post-modification application refers to the Schiffbase or Knoevenagel reaction of β-aldehyde polythioether with amine or nitrile monomers to prepare functional polythioethers with different thermal stabilities and optical properties.

[0026] The preparation method and the obtained product of the present invention have the following advantages and beneficial effects:

[0027] (1) The present invention designs and synthesizes acetylene aldehyde monomers based on the monomer structure. The synthesis conditions of the monomers are mild and there is no need to use highly active reagents (ethynyl magnesium bromide) and heavy metal oxides (chromium trioxide, etc.).

[0028] (2) The electron-withdrawing properties of the aldehyde group make the acetylenic monomer highly reactive, allowing it to polymerize with thiol compounds under non-catalytic conditions. This method is simple and efficient and can synthesize high molecular weight polymers.

[0029] (3) The polymerization process of the present invention generates no by-products and is atom-economical.

[0030] (4) The β-aldehyde polysulfide prepared by the present invention can realize the selective detection of hydrazine.

[0031] (5) The β-aldehyde polysulfide product obtained by the present invention has good thermal stability, high refractive index and excellent processability; and the polymer side chain has an aldehyde group with good derivatization, and a series of polysulfide with precise structure and advanced function can be prepared by various polymer post-modification methods. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 The β-formaldehyde polysulfide P1 and its corresponding monomer in CDCl 3 H NMR spectrum of .

[0033] Figure 2 The β-formaldehyde polysulfide P1 and its corresponding monomer in CDCl 3 Carbon NMR spectrum.

[0034] Figure 3 It is the refractive index curve of β-aldehyde polysulfide P1.

[0035] Figure 4 This is the fluorescence spectrum of β-formaldehyde polysulfide P1 solution at different hydrazine hydrate contents.

[0036] Figure 5 This is the selectivity result diagram of β-aldehyde polysulfide P1 for the detection of amine compounds. DETAILED DESCRIPTION

[0037] The present invention is further described in detail below in conjunction with embodiments and drawings, but the embodiments of the present invention are not limited thereto.

[0038] Example 1

[0039] Metal-free polymerization of acetyl aldehyde M1 with thiol compound M2 was used to prepare β-aldehyde polysulfide P1.

[0040]

[0041] Among them, monomer M1 was synthesized according to the synthesis method in the published literature (Green Chem., 2019, 21, 509.; J. Am. Chem. Soc. 2011, 133, 16901.); M2 was purchased from Anage Company.

[0042] Add 38.2 mg (0.1 mmol) of monomer M1 and 25.0 mg (0.1 mmol) of monomer M2 to a 10 mL polymerization tube, evacuate and replace nitrogen for 3 times, inject 0.4 mL of ultra-dry N,N-dimethylformamide (DMF) with a syringe, and after the monomer is completely dissolved, put it into an oil bath pot that has been kept at 60°C and react for 4 hours. After the reaction is completed, add 1 mL of chloroform, and drop the obtained polymer solution into 100 mL of vigorously stirred n-hexane, let it stand, filter, and dry to obtain β-aldehyde polysulfide P1. After measurement and analysis, the yield of the final product P1 is 86%, the weight average molecular weight is 40260, and the molecular weight distribution is 2.74 (the molecular weight and molecular weight distribution are determined by gel permeation chromatography equipped with a refractive index detector. Tetrahydrofuran is used as the mobile phase, the flow rate is 1.0 mL / min, and linear monodistributed polystyrene is used as the standard for calibration). The temperature of thermal weight loss of 5% weight fraction is 320°C.

[0043] Comparison of the NMR spectra of β-formaldehyde polysulfide P1 (C) and its corresponding monomers (A, B) (* represents solvent peak) is shown in Figure 1 and Figure 2 .from Figure 1 It can be seen that the chemical shift of the aldehyde hydrogen moves from 9.46 ppm in the acetylaldehyde monomer to 10.31 and 9.32 ppm in the polymer; and the chemical shift of the newly generated double bond hydrogen in the polymer appears at 6.63 and 5.80 ppm. Figure 2 It can be seen that the characteristic peaks of M1 at chemical shifts of 95.97ppm and 89.45ppm corresponding to the carbon-carbon triple bond disappeared in the polymer spectrum. Figure 1 and 2 The characterization results show that the monomers are almost completely polymerized to obtain the target polymer.

[0044] More importantly, because the polymer chain contains a large number of benzene rings, aldehyde groups, sulfur atoms and other primitives, the polymer has a very high refractive index in the range of 400-1700nm, such as Figure 3As shown, the value at 632.8 nm is as high as 1.7098, which is much higher than the refractive index of some traditional materials, such as polymethyl methacrylate, highlighting the broad application prospects of the obtained polymer in the optical field.

[0045] Example 2

[0046] Metal-free polymerization of acetyl aldehyde M1 with thiol compound M3 was used to prepare β-aldehyde polysulfide P2.

[0047]

[0048] Monomer M3 was purchased from TCI. 38.2 mg (0.1 mmol) of monomer M1 and 14.2 mg (0.1 mmol) of monomer M3 were added to a 10 mL polymerization tube, and the vacuum was replaced with nitrogen for 3 times. 0.4 mL of ultra-dry DMF was injected with a syringe. After the monomer was completely dissolved, it was placed in an oil bath pot that was kept at 60°C and reacted for 4 hours. After the reaction was completed, 1 mL of chloroform was added, and the obtained polymer solution was added dropwise to 100 mL of vigorously stirred n-hexane, allowed to stand, filtered, and dried to obtain β-aldehyde polysulfide P2. After measurement and analysis, the yield of the final product P2 was 80%, the weight average molecular weight was 42390, and the molecular weight distribution was 2.64. The temperature at which the weight fraction of thermal weight loss was 5% was 313°C, and the refractive index at 632.8 nm was 1.7117. 1 H NMR (500 MHz, CDCl 3 ), δ (TMS, ppm): 10.36, 9.33, 7.76, 7.58, 7.49, 6.93, 6.73, 6.58, 5.85.5.58, 1.99, 1.05, 0.65, 0.38.

[0049] Example 3

[0050] Metal-free polymerization of acetyl aldehyde M1 with thiol compound M4 was used to prepare β-aldehyde polysulfide P3.

[0051]

[0052] Monomer M4 was purchased from Anage Company. 38.2 mg (0.1 mmol) of monomer M1 and 14.2 mg (0.1 mmol) of monomer M4 were added to a 10 mL polymerization tube, and the vacuum was replaced with nitrogen 3 times. 0.4 mL of ultra-dry DMF was injected with a syringe. After the monomer was completely dissolved, it was placed in an oil bath pot that was kept constant at 60 ° C and reacted for 4 hours. After the reaction was completed, 1 mL of chloroform was added, and the obtained polymer solution was added dropwise to 100 mL of vigorously stirred n-hexane, allowed to stand, filtered, and dried to obtain β-aldehyde polysulfide P3. After measurement and analysis, the yield of the final product polysulfide P3 was 78%, the weight average molecular weight was 34150, and the molecular weight distribution was 2.98. The temperature at which the weight fraction of thermal weight loss was 5% was 321 ° C. 1 H NMR (500 MHz, CDCl 3 ), δ (TMS, ppm): 10.37, 10.21, 9.28, 7.73-7.10, 7.02-6.67, 5.79, 5.60, 1.88, 0.96, 0.62, 0.36, 0.10.

[0053] Example 4

[0054] Metal-free polymerization of acetyl aldehyde M5 with thiol compound M2 was used to prepare β-aldehyde polysulfide P4.

[0055]

[0056] Monomer M5 was synthesized according to the synthesis method in the published literature (Green Chem., 2019, 21, 509.; J. Am. Chem. Soc. 2011, 133, 16901.).

[0057] Add 29.8mg (0.1mmol) of monomer M5 and 25.0mg (0.1mmol) of monomer M2 to a 10mL polymerization tube, evacuate and replace with nitrogen 3 times, inject 0.4mL of ultra-dry DMF with a syringe, and after the monomers are completely dissolved, put them into an oil bath pot that has been kept at 60°C and react for 4 hours. After the reaction is completed, add 1mL of chloroform, and drop the obtained polymer solution into 100mL of vigorously stirred n-hexane, let it stand, filter, and dry to obtain β-aldehyde polysulfide P4. After measurement and analysis, the yield of the final product P4 is 84%, the weight average molecular weight is 22140, and the molecular weight distribution is 1.84. The temperature at which the weight fraction of thermal weight loss is 5% is 316°C, and the refractive index at 632.8nm is 1.7552. 1 H NMR (500 MHz, CDCl 3), δ (TMS, ppm): 10.35, 10.29, 9.33, 7.81, 7.75, 7.59, 7.53, 7.51, 7.38, 7.21, 7.18, 7.00, 6.83, 6.66, 5.79, 5.66, 1.53, 1.39, 1.35, 1.20, 1.18.

[0058] Example 5

[0059] Metal-free polymerization of acetyl aldehyde M5 with thiol compound M3 was used to prepare β-aldehyde polysulfide P5.

[0060]

[0061] Add 29.8mg (0.1mmol) of monomer M5 and 14.2mg (0.1mmol) of monomer M3 to a 10mL polymerization tube, evacuate and replace with nitrogen 3 times, inject 0.4mL of ultra-dry DMF with a syringe, and after the monomer is completely dissolved, put it into an oil bath pot that has been kept at 60°C and react for 4 hours. After the reaction is completed, add 1mL of chloroform, and drop the obtained polymer solution into 100mL of vigorously stirred n-hexane, let it stand, filter, and dry to obtain β-aldehyde polysulfide P5. After measurement and analysis, the yield of the final product P5 is 85%, the weight average molecular weight is 22100, and the molecular weight distribution is 1.79. The temperature at which the weight fraction of thermal weight loss is 5% is 325°C, and the refractive index at 632.8nm is 1.7510. 1 H NMR (500 MHz, CDCl 3 ), δ (TMS, ppm): 10.35, 10.18, 9.35, 9.25, 8.03, 7.76, 7.61, 7.48, 7.33, 6.97, 6.73, 6.58, 5.80, 5.53, 1.53, 1.49, 1.42, 1.36, 1.32.

[0062] Example 6

[0063] Metal-free polymerization of acetyl aldehyde M5 with thiol compound M4 was used to prepare β-aldehyde polysulfide P6.

[0064]

[0065] Add 29.8mg (0.1mmol) of monomer M5 and 14.2mg (0.1mmol) of monomer M4 to a 10mL polymerization tube, evacuate and replace with nitrogen 3 times, inject 0.4mL of ultra-dry DMF with a syringe, and after the monomer is completely dissolved, put it into an oil bath pot that has been kept at 60°C and react for 4 hours. After the reaction is completed, add 1mL of chloroform, and drop the obtained polymer solution into 100mL of vigorously stirred n-hexane, let it stand, filter, and dry to obtain β-aldehyde polysulfide P6. After measurement and analysis, the yield of the final product polysulfide P6 is 88%, the weight average molecular weight is 10850, and the molecular weight distribution is 1.93. The temperature at which the weight fraction of thermal weight loss is 5% is 319°C, and the refractive index at 632.8nm is 1.7557. 1 H NMR (500 MHz, CDCl 3 ), δ (TMS, ppm): 10.36, 10.20, 9.30, 9.20, 7.67, 7.50, 7.05, 6.89, 6.67, 6.60, 5.75, 5.44, 1.61, 1.48, 1.40, 1.31, 1.18.

[0066] Example 7

[0067] Application of β-aldehyde polysulfide in hydrazine detection. Hydrazine is widely used in chemical manufacturing processes such as pesticides, missiles and rocket propellants, etc. Moreover, hydrazine can be completely absorbed through the skin, causing irreversible damage to many organs of the human body. Therefore, the detection of hydrazine is of great significance for environmental safety and human health. The β-aldehyde polysulfide in the present invention contains a large number of aldehyde groups, and the DA intensity in the molecule is adjusted by the chemical reaction between the aldehyde groups and hydrazine, thereby changing the luminescent color and intensity of the polymer, and then realizing the detection of hydrazine. Taking P1 as an example, we use hydrazine hydrate as a model to verify the selective detection of hydrazine by β-aldehyde polysulfide. Figure 4 The fluorescence spectra of tetrahydrofuran solution of P1 at different hydrazine concentrations (0-250 equivalents) are shown in Figure 2. As the hydrazine hydrate content increases, the fluorescence intensity of P1 also increases. It can also be clearly seen from the illustration that the addition of hydrazine hydrate will cause a significant change in the fluorescence intensity of P1, and the fluorescence color changes from basically colorless to yellow-green. The minimum detection limit of P1 for hydrazine is 1.52×10 -6 M, showing excellent sensitivity. Figure 5 It is the selectivity of P1 for the detection of different amine compounds. By comparing the effects of different amine compounds with P1, it was found that only hydrazine hydrate can greatly enhance the fluorescence of P1, showing very good selectivity.

[0068] Example 8

[0069] Post-modification application of β-aldehyde polysulfide. Due to the rich and active chemical properties of aldehyde groups, a variety of post-modification pathways can be used to expand the structure and function of the resulting polymer. The Schiff base reaction of P1 and 2,6-dimethylaniline to obtain PM1 is used as an example to illustrate.

[0070]

[0071] Among them, 2,6-dimethylaniline was purchased from Bid Pharmaceuticals. 31.6 mg of polymer P1 was added to a 10 mL polymerization tube, 0.5 mL of redistilled tetrahydrofuran was added to dissolve the polymer, and then 1.5 mL of redistilled tetrahydrofuran containing 26.0 mg of 2,6-dimethylaniline was added dropwise. After the reactants were completely dissolved, they were placed in an oil bath pot at 60°C and reacted for 6 hours. After the reaction was completed, the obtained polymer solution was added dropwise to 100 mL of vigorously stirred n-hexane, allowed to stand, filtered, and dried to obtain 17.2 mg of the post-modified product PM2. 1 H NMR (500 MHz, CDCl 3 ), δ (TMS, ppm): 10.34, 9.88, 9.62, 9.31, 8.64, 8.01, 7.63-6.82, 6.66, 1.89, 0.96, 0.58, 0.29.

[0072] Example 9

[0073] The post-modification application of β-aldehyde polysulfide is illustrated by taking the Schiff base reaction of P1 with benzoyl hydrazide to obtain PM2 as an example.

[0074]

[0075] Among them, benzoyl hydrazide was purchased from Bid Pharmaceuticals. 31.6 mg of polymer P1 was added to a 10 mL polymerization tube, 0.5 mL of redistilled tetrahydrofuran was added to dissolve the polymer, and then 1.5 mL of redistilled tetrahydrofuran containing 13.6 mg of benzoyl hydrazide was added dropwise. After the reactants were completely dissolved, they were placed in an oil bath pot at 60 ° C and reacted for 6 hours. After the reaction was completed, the obtained polymer solution was added dropwise to 100 mL of vigorously stirred n-hexane, allowed to stand, filtered, and dried to obtain 36.2 mg of the post-modified product PM2. 1 HNMR (500MHz, CDCl 3 ), δ (TMS, ppm): 9.86, 9.58, 8.01-7.18, 5.13, 4.98, 3.96, 3.73, 3.11, 1.97, 1.05.

[0076] Example 10

[0077] The post-modification application of β-aldehyde polythioether is illustrated by taking the Knoevenagel reaction of P1 with diethyl cyanomethyl phosphate to obtain PM3 as an example.

[0078]

[0079] Wherein, diethyl cyanomethyl phosphate is purchased from Bi De Pharmaceutical Company. Add 5.0mg sodium hydride (60% dispersion in mineral oil) in a 10mL polymer tube, evacuate and change nitrogen 3 times, inject 1mL redistilled tetrahydrofuran with a syringe, drip 26.5mg diethyl cyanomethyl phosphate after ice bath half an hour, restore room temperature reaction half an hour, inject 1mL tetrahydrofuran solution containing P1 (31.6mg) with a syringe, after the reaction product is completely dissolved, put into an oil bath pot that has been constant at 40°C, and react for 6 hours. After the reaction ends, extract 3 times with chloroform / salt water, collect organic phase and spin-dry to obtain product. Products therefrom are dissolved with 1.0mL tetrahydrofuran, added dropwise to 100mL of vigorously stirred n-hexane, stand, filter, dry, and obtain 16.8mg post-modification product PM3. 1 H NMR (500 MHz, CDCl 3 ), δ (TMS, ppm): 7.86, 7.52, 7.30, 7.04-6.88, 5.58, 5.40, 5.21, 4.97, 2.06, 1.83, 0.61, 0.33, 0.15.

[0080] The above embodiments are preferred implementation modes of the present invention, but the implementation modes of the present invention are not limited to the above embodiments. Any other changes, modifications, substitutions, combinations, and simplifications that do not deviate from the spirit and principles of the present invention should be equivalent replacement methods and are included in the protection scope of the present invention.

Claims

1. A β-aldehyde polysulfide, characterized in that: The β-formaldehyde polysulfide has a general structural formula shown in formula (I): Wherein, n is an integer from 2 to 200, The R 1 Any one of the following chemical structural formulas, The R 2 Any one of the following chemical structural formulas: Wherein, m and h are integers of 1 to 15; * indicates the substitution position.

2. The method for preparing a β-aldehyde polysulfide according to claim 1, characterized in that: The method comprises the following preparation steps: in an inert atmosphere or air atmosphere, polymerizing a dibasic acetylene aldehyde compound of a structure of formula (II) and a dibasic thiol compound of a structure of formula (III) in an organic solvent, and separating the product to obtain a β-aldehyde polysulfide; 3. A method for preparing a β-aldehyde polysulfide according to claim 2, characterized in that: The organic solvent is one of tetrahydrofuran, toluene, 1,4-dioxane, dimethyl sulfoxide, N,N-dimethylformamide, dimethylacetamide and chloroform, or a mixture of two or more thereof.

4. The method for preparing a β-aldehyde polysulfide according to claim 2, characterized in that: The polymerization reaction temperature is 20-80° C., and the reaction time is 1-6 hours.

5. The method for preparing a β-aldehyde polysulfide according to claim 2, characterized in that: The molar ratio of the dibasic acetylene aldehyde compound to the dibasic thiol compound is 1:(1-1.1); the concentration of the dibasic acetylene aldehyde compound in the organic solvent is 0.05-0.5 mol / L.

6. The method for preparing a β-aldehyde polysulfide according to claim 2, characterized in that: The method for separating the product is as follows: after the reaction is completed, the product is dissolved in a solvent, then added into n-hexane for precipitation, the precipitate is collected, and dried to a constant weight to obtain β-aldehyde polysulfide.

7. Use of the β-aldehyde polysulfide according to claim 1 in detecting hydrazine.

8. The post-modification application of the β-aldehyde polysulfide according to claim 1, characterized in that: It refers to the preparation of polythioether by Schiff base or Knoevenagel reaction of β-aldehyde polythioether with amine or nitrile monomers.

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