Stable selenol and polyselenourethane thereof, and preparation and recovery methods and application of stable selenol and polyselenourethane

Abstract

The invention discloses stable selenol and poly (selenourethane) thereof, preparation and recovery methods and application, selenol is stable micromolecules with at least two degrees of functionality, and poly (selenourethane) is prepared by directly participating in polymerization of selenol. The selenol overcomes the limitation that selenium-containing small molecules are unstable in the environment, and the polyselenourethane has rich and adjustable performance, is stable in structure, simple in preparation method, high in reaction speed, few in side reaction in the polymerization process, high in molecular weight, suitable in polydispersity coefficient and excellent in optical performance, and can be applied to the field of electronic devices. Good mechanical properties are achieved in room-temperature and low-temperature environments; meanwhile, the polyselenourethane has good thermal responsiveness and oxygen responsiveness, chemical recovery of selenol can be achieved under the simple heating condition, the polyselenourethane can be degraded by reacting with oxygen, active oxygen and the like in the service environment, meanwhile, selenium-containing components capable of being biologically utilized are released, and the selenium-containing components can be recycled. And a new opportunity is provided for development of organic selenium chemistry and selenium-containing polymers and internal and external application of organisms.

Description

Technical Field

[0001] This invention relates to a stable selenol and its polyselenouric acid ester, preparation and recovery methods and applications. The polyselenouric acid ester is a novel dynamic selenium-containing polymer with good thermal and oxygen responsiveness, belonging to the field of selenium-containing polymers. Background Technology

[0002] Selenium-containing polymers have attracted widespread attention due to their excellent stimulus-response properties and bioactivity, making them promising for applications in biomedicine, high-refractive-index materials, and biodegradable and recyclable materials. However, despite the numerous reported selenium-containing structures, the structural diversity of selenium-containing polymers is mainly limited to selenide (R-Se-R) and diselelenide (R-Se-Se-R) bonds. Because the reactive selenium-containing functional groups are unstable, existing methods for constructing selenium-containing polymers typically employ traditional polymerization reactions (such as free radical polymerization, step-growth polymerization, and ring-opening polymerization), which introduce Se-Se bonds into the reactants and rely on the remaining functional groups (hydroxyl, amine, double bonds, etc.) in the reactants to participate in the polymerization reaction. This results in a limited variety of polymers with restricted functions and a lack of universality.

[0003] Polymerization using selenools (R-SeH) is a more efficient and simpler method for preparing selenium-containing polymers, and the Se-H bond energy is relatively low (276 kJ / mol). -1 This ensures its high reactivity and wide reaction range. However, the highly oxidizable nature of selenools hinders their separation, purification, and handling under atmospheric conditions, making them unsuitable for direct use in polymerization reactions. Although Pan Xiangqiang et al. developed an in-situ ring-opening selenolactone method to obtain selenools for polymerization reactions, this method is time-consuming (24 hours), and the obtained selenools are easily oxidized, limiting their application. Xu Huaping et al. synthesized a series of selenium-containing polymers containing diseleno bonds and selenide bonds, but their structures are relatively simple and lack thermal responsiveness, making it impossible to recover the selenium-containing components. Overall, current selenium-containing polymers suffer from problems such as simple structure, difficulty in recovery, and poor responsiveness. Summary of the Invention

[0004] Based on the above analysis, the present invention provides a stable selenool, a heat- and oxygen-responsive polyselenouric acid ester based on the stable selenool, and its preparation, recovery methods and applications.

[0005] The technical solution adopted in this invention is as follows: The stabilized selenool is a small selenool molecule with a β-oxygen structure, and the polyselenouric acid ester is obtained by directly reacting the selenool, having the following general structural formula: Wherein R1 is the portion of diisocyanate without two isocyanate groups, R2 is the intermediate segment of selenool without two selenool groups, and R3 is the portion of long-chain diol without two hydroxyl groups, and the molar amount of R1 should be the sum of the molar amounts of R2 and R3; x = any integer between 9 and 46, m = any integer between 20 and 100, n = any integer between 0 and 100, when n = 0 it is a two-component polyselenouric acid ester composed of isocyanate and selenool, and when n = 1 to 100 it is a three-component polyselenouric acid ester composed of isocyanate, selenool and long-chain diol.

[0006] Furthermore, the selenool contains at least 6 carbons in its molecular chain, preferably 8 carbons; and is a small molecule with at least two functions.

[0007] Furthermore, R1 is , , , One or more of them, where the wavy line represents the part connected to the molecular chain.

[0008] Furthermore, R2 is Where y = 0 or a positive integer, , , , , At least one of them.

[0009] Furthermore, R3 is , , , One or more of the following, where the wavy line represents the part connected to the molecular chain.

[0010] The stabilized selenool and the preparation method of polyselenouryl ester based on the stabilized selenool of the present invention are as follows: The method for preparing the stabilized selenol: Under ice bath conditions, elemental selenium, sodium borohydride, and ethanol were added to N,N-dimethylformamide in a molar ratio of 1:2:8. After the reaction system changed from dark brown to colorless, formic acid in an equimolar amount to sodium borohydride was added to form a selenochemical reagent. The reaction system was then brought to room temperature, and a brominated molecule with at least two functionalities was added, yielding a stable polyfunctional selenool. The stable polyfunctional selenool was then purified by ether extraction. The brominated molecule with at least two functionalities was prepared by a nucleophilic substitution reaction between an alcohol with the corresponding functionality and a brominated reagent.

[0011] The stabilized selenool can be directly reacted with diisocyanate monomers, dihalogenated monomers, diene monomers, diacetylene monomers, and dithiol monomers to obtain selenium-containing polymers.

[0012] Preparation method of two-component polyselenouric acid ester: The reaction temperature was controlled at 0-20℃. Compound I was dissolved in solvent I, and compound II was added and stirred until the reaction system became viscous. The reaction system was then precipitated in methanol, washed, and vacuum-treated to obtain a two-component polyselenouryl elastomer, wherein the molar ratio of compound I to compound II was 1:1.

[0013] Preparation method of three-component polyselenouric acid ester: Compound III and Compound II were mixed, and Catalyst I was added. The mixture was heated and stirred to carry out a prepolymerization reaction. The prepolymerization reaction temperature was controlled at 40-90℃, and the prepolymerization reaction time was controlled at 2-12 hours. After the reaction was completed, Solvent I was added, and Compound I was added and stirred until the reaction system became viscous. The reaction system was then precipitated in methanol, washed, and vacuum-treated to obtain a three-component polystyrene elastomer. The molar ratio of the sum of Compound I and Compound III to Compound II was 1:1.

[0014] Wherein, compound I is a difunctional selenool compound, compound II is a difunctional isocyanate compound, compound III is a polyol, and catalyst I is a nucleophilic polymerization catalyst.

[0015] Solvent I is one or a mixture of several of the following: isopentane, pentane, petroleum ether, hexane, cyclohexane, cyclopentane, ethyl acetate, diethyl ether, isopropyl ether, tetrahydrofuran, chloroform, dioxane, benzene, toluene, dichloromethane, acetone, acetonitrile, N,N-dimethylformamide, N,N-dimethylacetamide, and N-methylpyrrolidone.

[0016] The difunctional selenool compound may be one or a mixture of several of the following: polyethylene glycol diselenool, polyethylene glycol diselenool, polyethylene glycol diselenool, polyethylene glycol diselenool, polyethylene glycol diselenool, polyethylene glycol diselenool, heptaethylene glycol diselenool, and 1,1-diselenool diphenyl ether; the difunctional isocyanate compound may be toluene diisocyanate (TDI), diphenylmethane diisocyanate (MDI), naphthalene diisocyanate (NDI), terephthalene diisocyanate (PPDI), 1,3-phenylene diisocyanate, dimethyl biphenyl diisocyanate (TODI), polymethylene polyphenyl isocyanate (PAPI), and 1,6-hexanediol. One or a mixture of several of the following isocyanates: trimethyl-1,6-hexamethylene diisocyanate (TMHDI), trimethylhexane diisocyanate, phenylenediamine diisocyanate (XDI), tetramethyl-isophthalamide diisocyanate (TMXDI), isophorone diisocyanate (IPDI), 1,4-cyclohexane diisocyanate (CHDI), hydrogenated methylene diphenyl isocyanate (HMDI), L-lysine diisocyanate, hydrogenated toluene diisocyanate, cyclohexane diisocyanate (HXDI), and norbornene diisocyanate (NBDI).

[0017] The polyol mentioned is a polyester polyol, a polyether polyol, or other polyols. Polyester polyols generally refer to ester substances containing two or more -OH groups in their compound structure, and can be selected from one of the following: polyhexyl adipate diol, polybutylene adipate diol, polypropylene adipate diol, polyethylene adipate diol, polydiethylene adipate diol, polybutylene phthalate diol, polybutylene phthalate diol, polyethylene phthalate diol, polycaprolactone diol, polycaprolactone triol, polyhexylene carbonate diol, and polyhexamethylene carbonate diol. One or more types; the number average molecular weight of the polyester polyol is 500-10000; the polyether polyol generally refers to an ether substance containing two or more -OH groups in its compound structure, and may be selected from one or more of polytetrahydrofuran glycol, polypropylene glycol, polyethylene glycol, polytrimethylene ether glycol, bisphenol A polyoxyethylene ether glycol, polypropylene triol, propylene oxide-ethylene oxide co-ether triol, and polypropylene tetraol; the number average molecular weight of the polyether polyol is 500-10000. The other polyols may be selected from one or more of the following: glycerol, pentaerythritol, sorbitol, castor oil, soybean oil polyol, palm oil polyol, rosin ester polyol, trimethylolpropane, hydroxyl-terminated polybutadiene, hydroxyl-terminated hydrogenated polybutadiene, hydroxyl-terminated polybutadiene-acrylonitrile, hydroxyl-terminated styrene-butadiene liquid rubber, hydroxyl-terminated polyisoprene, hydroxyl-terminated hydrogenated polyisoprene, polystyrene-allyl copolymer polyol, polydimethylsiloxane polyol, and tetrahydrofuran-propylene oxide copolymer diol.

[0018] The nucleophilic polyaddition catalyst is one or a mixture of several of the following: dibutyltin dilaurate, stannous octoate, dibutyltin diacetate, triphenylbismuth, triethylenediamine, bis(dimethylaminoethyl) ether, dimethylethanolamine, trimethylhydroxyethylpropanediamine, N,N-bis(dimethylaminopropyl)isopropanolamine, N,N,N'-trimethyl-N'-hydroxyethyldiaminoethyl ether, N,N-dimethylcyclohexylamine, N-ethylmorpholine, N,N-dimethylbenzylamine, and N,N-dimethylhexadecanamine.

[0019] The polyselenouryl ester described herein is both thermally and oxygen-responsive.

[0020] The degradation and recycling of polyselenouric acid ester can be achieved by utilizing its thermal responsiveness. The method is as follows: polyselenouric acid ester is placed in solvent I and heated at 40-100℃ for 0.01-2 days to complete the degradation. After adding deionized water, the selenium-containing monomer precipitates at the bottom of the container and is recovered to obtain the selenium-containing component. The volume ratio of deionized water to solvent I is (0.5-10):1.

[0021] The oxygen responsiveness of the polyselenocyanate can be utilized in the preparation of selenium-releasing drugs. The polyselenocyanate can react with oxygen and reactive oxygen species in the service environment to degrade the polyselenocyanate and release selenium-containing components, which can be utilized by organisms.

[0022] This invention provides, on the one hand, the preparation of a selenool with a β-oxygen structure. This selenool overcomes the limitation of the instability of selenium-containing small molecules in the environment, thereby obtaining a high-purity selenool for polymerization reactions requiring a quantitative functional group ratio. On the other hand, existing selenium-containing polymers are limited in variety and their preparation methods are singular, only allowing the introduction of the selenium-containing structure into the reactant monomer, relying on the participation of other functional groups while selenium cannot participate in the polymerization reaction. This invention overcomes this limitation by directly reacting the aforementioned selenool with an isocyanate of at least two functionalities to prepare a polymer polyselenourate with a novel selenium-containing structure and selenourate bonds. Polyselenouryl esters (PSEs) possess a wide range of tunable properties, stable structure, simple preparation methods, rapid reaction rates, few side reactions during polymerization, high molecular weight, and suitable polydispersity index. They also exhibit excellent optical properties and good mechanical properties at both room temperature and low temperatures. Furthermore, PSEs demonstrate good thermal and oxygen responsiveness, enabling the chemical recovery of selenools under simple heating conditions. They can also react with oxygen and reactive oxygen species in the service environment to degrade PSEs, releasing bioavailable selenium-containing components. This provides new opportunities for the development of organoselenium chemistry, selenium-containing polymers, and their in vitro and in vivo applications.

[0023] The beneficial effects of this invention are: This invention provides a stable selenool and its polyselenouric acid ester, a method for preparation and recovery, and applications. The polyselenouric acid ester forms a selenouric acid ester bond through a direct reaction between the selenool group and the isocyanate group, exhibiting good thermal and oxygen responsiveness. This results in good thermal reversibility and reprocessability, and the ester can be degraded by oxygen during service, releasing bioavailable selenium, thus possessing promising in vitro and in vivo applications. The polymerization reaction is fast and low-cost, producing materials with good mechanical properties. Furthermore, the chemical recovery of selenium-containing monomers can be achieved under heating conditions, providing new opportunities for the development of organoselenium chemistry, selenium-containing polymers, and their in vitro and in vivo applications. Attached Figure Description

[0024] Figure 1 The 1H NMR spectrum of the stable selenool prepared in Example 1 of this invention.

[0025] Figure 2 The nuclear magnetic resonance selenium spectrum of the stable selenol prepared in Example 1 of this invention.

[0026] Figure 3 This is a comparison of the stability of the stable selenool prepared in Example 1 of the present invention with that of other selenools.

[0027] Figure 4 The reaction formula for synthesizing the two-component polyselenouric acid ester of Example 2 of the present invention.

[0028] Figure 5 The nuclear magnetic resonance hydrogen spectrum of the two-component polyselenouric acid ester prepared in Example 2 of the present invention.

[0029] Figure 6 The nuclear magnetic resonance selenium spectrum of the two-component polyselenouric acid ester prepared in Example 2 of the present invention.

[0030] Figure 7 The GPC molecular weight spectrum of the two-component polyselenouric acid ester prepared in Example 2 of this invention is shown.

[0031] Figure 8 DSC curve of the two-component polyselenouric acid ester prepared in Example 2 of this invention Figure 9 TGA curve of the two-component polyselenouric acid ester prepared in Example 2 of this invention. Figure 10 The stress-strain curve of the two-component polyselenouric acid ester prepared in Example 2 of the present invention.

[0032] Figure 11 The ATR spectrum of the two-component polyselenouric acid ester prepared in Example 2 of this invention is shown.

[0033] Figure 12 The DMA spectrum of the two-component polyselenouric acid ester prepared in Example 2 of this invention.

[0034] Figure 13The 1H NMR spectrum of the two-component polyselenouric acid ester prepared in Example 3 of this invention.

[0035] Figure 14 The nuclear magnetic resonance selenium spectrum of the two-component polyselenouric acid ester prepared in Example 3 of the present invention.

[0036] Figure 15 The image shows the GPC molecular weight spectrum of the two-component polyselenouric acid ester prepared in Example 3 of this invention.

[0037] Figure 16 DSC curve of the two-component polyselenouric acid ester prepared in Example 3 of this invention Figure 17 The TGA curve of the two-component polyselenourate prepared in Example 3 of this invention. Figure 18 The stress-strain curve of the two-component polyselenouric acid ester prepared in Example 3 of the present invention.

[0038] Figure 19 The 1H NMR spectrum of the two-component polyselenouric acid ester prepared in Example 4 of this invention.

[0039] Figure 20 The nuclear magnetic resonance selenium spectrum of the two-component polyselenouric acid ester prepared in Example 4 of the present invention.

[0040] Figure 21 The GPC molecular weight spectrum of the two-component polyselenouric acid ester prepared in Example 4 of this invention is shown.

[0041] Figure 22 DSC curve of the two-component polyselenouric acid ester prepared in Example 4 of this invention Figure 23 The TGA curve of the two-component polyselenourate prepared in Example 4 of this invention. Figure 24 The stress-strain curve of the two-component polyselenouric acid ester prepared in Example 4 of the present invention.

[0042] Figure 25 The 1H NMR spectrum of the two-component polyselenouric acid ester prepared in Example 5 of this invention.

[0043] Figure 26 The nuclear magnetic resonance selenium spectrum of the two-component polyselenouric acid ester prepared in Example 5 of the present invention.

[0044] Figure 27 The image shows the GPC molecular weight spectrum of the two-component polyselenouric acid ester prepared in Example 5 of this invention.

[0045] Figure 28 DSC curve of the two-component polyselenouric acid ester prepared in Example 5 of this invention Figure 29 The TGA curve of the two-component polyselenouric acid ester prepared in Example 5 of this invention. Figure 30 The stress-strain curve of the two-component polyselenouric acid ester prepared in Example 5 of the present invention.

[0046] Figure 31 The 1H NMR spectrum of the two-component polyselenouric acid ester prepared in Example 7 of this invention.

[0047] Figure 32 The nuclear magnetic resonance selenium spectrum of the two-component polyselenouric acid ester prepared in Example 7 of the present invention.

[0048] Figure 33 The GPC molecular weight spectrum of the two-component polyselenouric acid ester prepared in Example 7 of this invention is shown.

[0049] Figure 34 DSC curve of the two-component polyselenouric acid ester prepared in Example 7 of this invention Figure 35 TGA curve of the two-component polyselenouric acid ester prepared in Example 7 of this invention. Figure 36 The stress-strain curve of the two-component polyselenouric acid ester prepared in Example 7 of the present invention.

[0050] Figure 37 This is a schematic diagram illustrating the recovery of the two-component polyselenouric acid ester prepared in Example 3 of the present invention.

[0051] Figure 38 The photon nuclear magnetic resonance (NMR) spectrum of the selenium-containing raw material after the recovery of the two-component polyselenouric acid ester prepared in Example 3 of this invention is shown.

[0052] Figure 39 The nuclear magnetic resonance selenium spectrum of the selenium-containing raw material after the recovery of the two-component polyselenouric acid ester prepared in Example 3 of the present invention.

[0053] Figure 40 The image shows the GPC molecular weight spectrum of the two-component polyselenouric acid ester prepared in Comparative Example 1 of this invention.

[0054] Figure 41 The stress-strain curve of the two-component polyselenouric acid ester prepared in Comparative Example 1 of this invention is shown. Detailed Implementation

[0055] The technical solution of the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0056] Example 1 At 0℃, 4 g of elemental selenium, 4 g of sodium borohydride, and 14 mL of isopropanol were added to a reaction vessel containing 200 mL of N,N-dimethylformamide. The mixture was stirred thoroughly until the solution changed from dark brown to colorless. Then, 4 mL of formic acid was slowly added, followed by 7.8 g of dibromohexanediol. The mixture was stirred thoroughly for 5 h. After the reaction was completed, the mixture was extracted three times with 200 mL of diethyl ether. The extracted diethyl ethers were combined and washed twice with 200 mL of saturated brine. The washed diethyl ethers were concentrated to obtain pure hexanediol diselenol, with a total yield of 61%.

[0057] 10 mg of polyethylene glycol diselenool was dissolved in 600 μL of deuterated chloroform solvent, and nuclear magnetic resonance (NMR) spectroscopy (H NMR) and NMR spectroscopy (NMR saturation) were performed. The results are as follows: Figure 1 and Figure 2 As shown, no oxide impurity peaks were observed in the NMR spectrum, proving that the selenool has very high purity.

[0058] Using the same method, triethylene glycol diselenol with a six-carbon structure and tetraethylene glycol diselenol with an eight-carbon structure were synthesized. 20 mg of each of the three selenools were dissolved in 600 μL of deuterated chloroform solvent, and 10 equivalents of deuterated dimethyl sulfoxide were added as an oxide to oxidize the selenools. The oxidation rates were then determined, and the results are as follows: Figure 3 As shown, all three selenools exhibit good stability, with the selenool with an eight-carbon structure exhibiting the best stability.

[0059] Example 2 Nitrogen gas was introduced to maintain a nitrogen atmosphere in the flask. 1.62 g (10 mmol) of hexamethylene diisocyanate, 3.25 g of polyethylene glycol diselenyl alcohol (10 mmol), and 40 mL of N,N-dimethylacetamide were added to the flask. The mixture was mechanically stirred at 200 rpm for 0.5 h. The reaction mixture was then precipitated in 200 mL of methanol, washed three times, and evacuated for 24 h to remove excess solvent, yielding a pale yellow polyselenouric acid ester solid.

[0060] Figure 4 The reaction formula for component two, polyselenouryl ester, in this embodiment is as follows.

[0061] 20 mg of the obtained polyselenouric acid was weighed and dissolved in 600 μL of deuterated dimethyl sulfoxide solvent. The results were analyzed using 1H NMR and 1S NMR spectra. Figure 5 and Figure 6 As shown, the structure of polyselenouryl ester was verified.

[0062] The test was performed using gel permeation chromatography with tetrahydrofuran as the eluent, and calibration was performed using a monodisperse polymethyl methacrylate standard. The results are as follows: Figure 7 As shown.

[0063] Weigh 10 mg of the obtained polyselenouryl ester and perform DSC testing under nitrogen protection, with a temperature change rate of 10 K / min, a temperature range of -80℃ to 40℃, in rise-fall-rise mode. The obtained curve is shown below. Figure 8 As shown; the sample was heated from room temperature at a rate of 10 K / min, and the resulting TGA curve is shown. Figure 9 As shown; Referring to GB / T 1040.2-2006, the prepared samples were cut into dumbbell shapes and tested using an electronic universal testing machine equipped with a 100N sensor. The tensile speed for a single tensile test was 50 mm / min. At least three samples from each group were tested, and the average value was taken. The resulting stress-strain curves are shown below. Figure 10 As shown, the obtained sample has good mechanical properties.

[0064] The ATR spectrum of Example 2 is as follows Figure 11 As shown in the figure, the characteristic absorption peak of selenocyanide (~1730 nm) is present. -1 This further clarifies the structure of polyselenouryl ester.

[0065] The DMA spectrum of Example 2 is as follows Figure 12 As shown, its thermodynamic properties were further tested, confirming the glass transition temperature of the material.

[0066] Example 3 Nitrogen gas was introduced to maintain a nitrogen atmosphere in the flask. 2.62 g (10 mmol) of dicyclohexylmethane diisocyanate, 3.69 g of polyethylene glycol diselenyl alcohol (10 mmol), and 40 mL of N,N-dimethylformamide were added to the flask. The mixture was mechanically stirred at 200 rpm for 0.5 h. The reaction mixture was then precipitated in 200 mL of methanol, washed three times, and evacuated for 24 h to remove excess solvent, yielding a pale yellow polyselenouric acid ester solid.

[0067] 20 mg of the obtained polyselenouric acid was weighed and dissolved in 600 μL of deuterated N,N-dimethylformamide. The resulting proton NMR and selenium NMR spectra were analyzed. The results are as follows: Figure 13 and Figure 14 As shown, the structure of polyselenouryl ester was verified.

[0068] The test was performed using gel permeation chromatography with tetrahydrofuran as the eluent, and calibration was performed using a monodisperse polymethyl methacrylate standard. The results are as follows: Figure 15 As shown.

[0069] Weigh 10 mg of the obtained polyselenouryl ester and perform DSC testing under nitrogen protection, with a temperature change rate of 10 K / min, a temperature range of -80℃ to 80℃, in a rising / falling-rising mode. The obtained curve is shown below. Figure 16 As shown; the sample was heated from room temperature at a rate of 10 K / min, and the resulting TGA curve is shown. Figure 17 As shown; Under the same conditions as in Example 2, the mechanical properties of the polystyrene selenide in Example 3 were tested, and the resulting stress-strain curves are shown below. Figure 18 As shown.

[0070] Example 4 Nitrogen gas was introduced to maintain a nitrogen atmosphere in the flask. 2.22 g (10 mmol) of isophorone diisocyanate, 3.69 g of polyethylene glycol diselenyl alcohol (10 mmol), and 40 mL of N,N-dimethylformamide were added to the flask. The mixture was mechanically stirred at 200 rpm for 0.5 h. The reaction mixture was then precipitated in 200 mL of methanol, washed three times, and evacuated for 24 h to remove excess solvent, yielding a pale yellow polyselenouric acid ester solid.

[0071] 20 mg of the obtained polyselenouric acid was weighed and dissolved in 600 μL of deuterated N,N-dimethylformamide. The resulting proton NMR and selenium NMR spectra were analyzed. The results are as follows: Figure 19 and 20 As shown, the structure of polyselenouryl ester was verified.

[0072] The test was performed using gel permeation chromatography with tetrahydrofuran as the eluent, and calibration was performed using a monodisperse polymethyl methacrylate standard. The results are as follows: Figure 21 As shown.

[0073] Weigh 10 mg of the obtained polyselenouryl ester and perform DSC testing under nitrogen protection, with a temperature change rate of 10 K / min, a temperature range of -80℃ to 80℃, in a rising / falling-rising mode. The obtained curve is shown below. Figure 22 As shown; the sample was heated from room temperature at a rate of 10 K / min, and the resulting TGA curve is shown. Figure 23 As shown; Under the same conditions as in Example 2, the mechanical properties of the polystyrene selenium in Example 4 were tested, and the resulting stress-strain curves are shown below. Figure 24 As shown.

[0074] Example 5 Nitrogen gas was introduced to maintain a nitrogen atmosphere in the flask. 1.88 g (10 mmol) of m-phenylenedimethyl diisocyanate, 3.69 g of polyethylene glycol diselenyl alcohol (10 mmol), and 40 mL of N,N-dimethylformamide were added to the flask. The mixture was mechanically stirred at 200 rpm for 0.5 h. The reaction mixture was then precipitated in 200 mL of methanol, washed three times, and evacuated for 24 h to remove excess solvent, yielding a pale yellow polyselenouric acid ester solid.

[0075] 20 mg of the obtained polyselenouric acid was weighed and dissolved in 600 μL of deuterated N,N-dimethylformamide. The resulting proton NMR and selenium NMR spectra were analyzed. The results are as follows: Figure 25 and Figure 26 As shown, the structure of polyselenouryl ester was verified.

[0076] The test was performed using gel permeation chromatography with tetrahydrofuran as the eluent, and calibration was performed using a monodisperse polymethyl methacrylate standard. The results are as follows: Figure 27 As shown.

[0077] Weigh 10 mg of the obtained polyselenouryl ester and perform DSC testing under nitrogen protection, with a temperature change rate of 10 K / min, a temperature range of -80℃ to 40℃, in rise-fall-rise mode. The obtained curve is shown below. Figure 28 As shown; the sample was heated from room temperature at a rate of 10 K / min, and the resulting TGA curve is shown. Figure 29 As shown; Under the same conditions as in Example 2, the mechanical properties of the polystyrene selenide in Example 5 were tested, and the resulting stress-strain curves are shown below. Figure 30 As shown.

[0078] Example 6 Nitrogen gas was introduced to maintain a nitrogen atmosphere in the flask. 2.22 g (10 mmol) of hexamethylene diisocyanate, 2.50 g (10 mmol) of 1,1-diselenoyl p-phenylene diethyl ether, and 40 mL of tetrahydrofuran were added to the flask. The mixture was mechanically stirred at 200 rpm for 0.5 h. The reaction mixture was then precipitated in 200 mL of methanol, washed three times, and evacuated under vacuum for 24 h to remove excess solvent, yielding a white polyselenouryl urethane solid.

[0079] Example 7 Nitrogen gas was introduced to maintain a nitrogen atmosphere in the flask. Once the temperature reached 60 °C, 2.22 g (10 mmol) of hexamethylene diisocyanate, 10 g of polytetrahydrofuran-2000 (5 mmol), and 0.01 g of butyltin dilaurate were added to the flask. The mixture was mechanically stirred at 200 rpm for 3 h. Then, 50 mL of ice-cold N,N-dimethylformamide solvent was added to lower the reaction temperature to 0 °C. Next, 1.60 g of tetraethylene glycol diselenyl alcohol solution dissolved in 10 mL of N,N-dimethylacetamide was slowly added dropwise to the reactants. The mixture was magnetically stirred at 200 rpm for 0.5 h to obtain a polyurethane elastomer. The obtained product was washed three times with methanol and subjected to vacuum for 24 h to remove excess solvent, yielding a white solid of polyselenourate.

[0080] 20 mg of the obtained polyselenouric acid was weighed and dissolved in 600 μL of deuterated N,N-dimethylformamide. The resulting proton NMR and selenium NMR spectra were analyzed. The results are as follows: Figure 31 and Figure 32 As shown, the structure of the three-component polyselenouric acid ester was verified.

[0081] The test was performed using gel permeation chromatography with tetrahydrofuran as the eluent, and calibration was performed using a monodisperse polymethyl methacrylate standard. The results are as follows: Figure 33 As shown.

[0082] Weigh 10 mg of the obtained polyselenouryl ester and perform DSC testing under nitrogen protection, with a temperature change rate of 10 K / min, a temperature range of -50℃ to 160℃, in rise-fall-rise mode. The obtained curve is shown in Figure 1. Figure 34 As shown; the sample was heated from room temperature at a rate of 10 K / min, and the resulting TGA curve is shown. Figure 35 As shown; Under the same conditions as in Example 2, the mechanical properties of the polystyrene in Example 7 were tested. Due to the addition of the diol soft segment, its mechanical properties were greatly improved, and the resulting stress-strain curves are shown below. Figure 36 As shown.

[0083] Example 8 The polyselenocyanate synthesized in Example 3 was chemically recovered. 2 g of polyselenocyanate was dissolved in 20 mL of DMSO, heated to 100°C, and stirred for 20 h. After stirring, the heated system was cooled, resulting in a large amount of white precipitate. The filtrate was collected by filtration; it was an oxide of polyethylene glycol diselenocyanate. This precipitate was precipitated in 100 mL of deionized water, and the yellow precipitate was collected by centrifugation at 8000 rpm and washed three times with 100 mL of water. The resulting yellow viscous substance was dissolved in 50 mL of ethanol, and under nitrogen protection in an ice bath, 1 g of sodium borohydride was added. After reacting for 15 min, 7 g of citric acid was added. The mixture was transferred to a separatory funnel, and 50 mL of deionized water and 100 mL of ethyl acetate were added. The mixture was washed twice with 100 mL of saturated ammonium chloride solution, and then twice with 100 mL of saturated brine. The organic phase was collected, and rotary evaporation yielded the recovered product, polyethylene glycol diselenocyanate (1.02 g).

[0084] Among them, the degradation images of polyselenouryl are as follows: Figure 37 As shown, a large amount of white precipitate appeared after cooling; The proton and selenium spectra of the recovered polyethylene glycol diselenool are as follows: Figure 38 and Figure 39 As shown, the selenool monomer recovered using this method has high purity, consistent with that before the reaction.

[0085] Comparative Example 1 Nitrogen gas was introduced to maintain a nitrogen atmosphere in the flask. 1.62 g (10 mmol) of hexamethylene diisocyanate, 2.90 g of polyethylene glycol diselenoyl alcohol (9 mmol), and 40 mL of N,N-dimethylacetamide were added to the flask. The mixture was mechanically stirred at 200 rpm for 0.5 h. The reaction system was then precipitated in 200 mL of methanol, washed three times, and evacuated for 24 h to remove excess solvent, yielding a pale yellow polyselenouryl ester solid. At this point, due to the non-1:1 functional group ratio of isocyanate to selenol, the polymerization was incomplete, resulting in a low molecular weight and poor mechanical properties in the polyselenouryl ester product.

[0086] The test was performed using gel permeation chromatography with tetrahydrofuran as the eluent, and calibration was performed using a monodisperse polymethyl methacrylate standard. The results are as follows: Figure 40 As shown.

[0087] Under the same conditions as in Example 2, the mechanical properties of the polystyrene in Comparative Example 1 were tested. Due to its low molecular weight and poor mechanical properties, the obtained stress-strain curve is as follows. Figure 41 As shown.

[0088] The embodiments of the present invention have been described above. However, the present invention is not limited to the above embodiments. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A stable selenol, characterized in that, The stabilized selenool is a small selenool molecule with a β-oxygen structure, containing at least 6 carbons in its molecular chain and having at least two functionalities; the synthesis method of the selenool includes the following steps: Under ice bath conditions, elemental selenium, sodium borohydride, and ethanol were added to N,N-dimethylformamide in a molar ratio of 1:2:

8. After the reaction system changed from dark brown to colorless, formic acid in an equimolar amount to sodium borohydride was added to form a selenochemical. The reaction system was then brought to room temperature, and a bromine molecule with at least two functionalities was added. The reaction yielded a stable polyfunctional selenool, which was then purified by ether extraction. The bromine molecule with at least two functionalities was prepared by a nucleophilic substitution reaction between an alcohol with the corresponding functionality and a bromine molecule.

2. The stabilized selenol according to claim 1, characterized in that, The selenool can react directly with diisocyanate monomers, dihalogenated monomers, diene monomers, diacetylene monomers, and dithiol monomers to obtain selenium-containing polymers.

3. A polyselenouryl ester based on stabilized selenol, characterized in that, The stabilized selenool as described in claim 1, wherein the polyselenouric acid ester is prepared by direct reaction of the selenool and has the following general structural formula: Wherein R1 is the portion of diisocyanate without two isocyanate groups, R2 is the intermediate segment of selenool without two selenool groups, and R3 is the portion of long-chain diol without two hydroxyl groups. The molar amount of R1 is the sum of the molar amounts of R2 and R3. x is any integer between 9 and 46, m is any integer between 20 and 100, and n is any integer between 0 and 100. When n=0, it is a two-component polyselenouric acid ester composed of isocyanate and selenool. When n=1 to 100, it is a three-component polyselenouric acid ester composed of isocyanate, selenool, and long-chain diol.

4. The polyselenouric acid ester according to claim 3, characterized in that, The selenool molecular chain contains 8 carbons.

5. The polyselenouric acid ester according to claim 3, characterized in that, R1 is selected from , , , At least one of them; R2 is selected from , , , , , At least one of the following, where y = 0 or a positive integer; R3 is selected from , , , At least one of them.

6. The method for preparing polyselenouric acid ester as described in claim 3, characterized in that, The preparation method of the two-component polyselenouric acid elastomer is as follows: the reaction temperature is controlled at 0-20℃, compound I is dissolved in solvent I, compound II is added and stirred until the reaction system becomes viscous, the reaction system is precipitated in methanol, washed, and vacuum treated to obtain the two-component polyselenouric acid elastomer, wherein the molar ratio of compound I to compound II is 1:1; compound I is a difunctional selenool compound, and compound II is a difunctional isocyanate compound; The preparation method of the three-component polyselenouric acid elastomer is as follows: Compound III and Compound II are mixed, catalyst I is added, and the mixture is heated and stirred to carry out a prepolymerization reaction. The prepolymerization reaction temperature is controlled at 40-90℃, and the prepolymerization reaction time is controlled at 2-12 hours. After the reaction is completed, solvent I is added, compound I is added, and the mixture is stirred until the reaction system becomes viscous. The reaction system is then precipitated in methanol, washed, and vacuum-treated to obtain the three-component polyselenouric acid elastomer. The molar ratio of the sum of compound I and compound III to compound II is 1:

1. Compound III is a polyol, and catalyst I is a nucleophilic polyaddition catalyst.

7. The preparation method according to claim 6, characterized in that, Solvent I is one or a mixture of several of the following: isopentane, pentane, petroleum ether, hexane, cyclohexane, cyclopentane, ethyl acetate, diethyl ether, isopropyl ether, tetrahydrofuran, chloroform, dioxane, benzene, toluene, dichloromethane, acetone, acetonitrile, N,N-dimethylformamide, N,N-dimethylacetamide, and N-methylpyrrolidone. The difunctional selenool compound is one or a mixture of several of the following: polyethylene glycol diselenool, polyethylene glycol diselenool, polyethylene glycol diselenool pentaethylene glycol diselenool, polyethylene glycol diselenool hexaethylene glycol diselenool, polyethylene glycol diselenool heptaethylene glycol diselenool, and 1,1-diselenool diethyl ether. The difunctional isocyanate compound is at least one selected from the following: toluene diisocyanate (TDI), diphenylmethane diisocyanate (MDI), naphthalene diisocyanate (NDI), terephthalene diisocyanate (PPDI), 1,3-phenylene diisocyanate, dimethylbiphenyl diisocyanate (TODI), polymethylene polyphenyl isocyanate (PAPI), 1,6-hexamethylene diisocyanate (HDI), trimethyl-1,6-hexamethylene diisocyanate (TMHDI), trimethylhexamethylene diisocyanate, phenylene diisocyanate (XDI), tetramethyl-m-phenylene diisocyanate (TMXDI), isophorone diisocyanate (IPDI), 1,4-cyclohexane diisocyanate (CHDI), hydrogenated methylene diphenyl isocyanate (HMDI), L-lysine diisocyanate, hydrogenated toluene diisocyanate, cyclohexane diisocyanate (HXDI), and norbornane diisocyanate (NBDI). The polyol is one or more of polyester polyol, polyether polyol, or other polyols; the polyester polyol is an ester containing two or more -OH groups in its structure, with a number average molecular weight of 500-10000; the polyether polyol is an ether containing two or more -OH groups in its structure, with a number average molecular weight of 500-10000; the other polyols are at least one of glycerol, pentaerythritol, sorbitol, castor oil, soybean oil polyol, palm oil polyol, rosin ester polyol, trimethylolpropane, hydroxyl-terminated polybutadiene, hydroxyl-terminated hydrogenated polybutadiene, hydroxyl-terminated polybutadiene-acrylonitrile, hydroxyl-terminated styrene-butadiene liquid rubber, hydroxyl-terminated polyisoprene, hydroxyl-terminated hydrogenated polyisoprene, polystyrene-allyl copolymer polyol, polydimethylsiloxane polyol, and tetrahydrofuran-propylene oxide copolymer diol. The nucleophilic polyaddition catalyst is at least one selected from the following: dibutyltin dilaurate, stannous octoate, dibutyltin diacetate, triphenylbismuth, triethylenediamine, bis(dimethylaminoethyl) ether, dimethylethanolamine, trimethylhydroxyethylpropanediamine, N,N-bis(dimethylaminopropyl)isopropanolamine, N,N,N'-trimethyl-N'-hydroxyethyldiaminoethyl ether, N,N-dimethylcyclohexylamine, N-ethylmorpholine, N,N-dimethylbenzylamine, and N,N-dimethylhexylamine.

8. The polyselenouric acid ester according to claim 3, characterized in that, The polyselenouryl ester is both thermoresponsive and oxygen responsive.

9. The method for degradation and recycling of polyselenouryl ester according to claim 3, characterized in that, The thermal responsiveness of the polyselenouric acid ester is used to achieve the degradation and recovery of selenium-containing components. The polyselenouric acid ester is placed in solvent I and heated at 40-100℃ for 0.01-2 days to complete the degradation. After adding deionized water, the selenium-containing monomer precipitates at the bottom of the container and is recovered to obtain the selenium-containing components. The volume ratio of deionized water to solvent I is (0.5-10):

1.

10. The use of polyselenouric acid ester as described in claim 3 in the preparation of selenium-releasing drugs, characterized in that, The polyselenouric acid ester utilizes its oxygen responsiveness to react with oxygen or reactive oxygen species in the service environment to degrade the polyselenouric acid ester and release selenium-containing components for use by organisms.

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