Degradable disulfide-containing peroxide ester initiator and its application in preparation of degradable branched polymers
By using peroxide ester compounds containing degradable disulfide bonds and peroxy bonds as initiators, degradable branched polymers are synthesized under conventional free radical polymerization conditions. This solves the problems of complex synthesis methods, high costs, and unsatisfactory products in existing technologies, and realizes efficient, simple, and environmentally friendly branched polymer synthesis.
Patent Information
- Application Number
- CN202510120344.4
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- Filing Date
- 2025-01-25
- Publication Date
- 2025-11-25
- Estimated Expiration
- 2045-01-25
AI Technical Summary
Existing technologies struggle to efficiently synthesize biodegradable branched polymers under conventional free radical polymerization conditions. Furthermore, the synthesis methods are complex and costly, the products have low molecular weights and wide molecular weight distributions, the branching points are weak chemical bonds, the branched monomers are unstable and difficult to degrade, and they pose significant environmental hazards.
A novel free radical initiator, a peroxide ester compound containing degradable disulfide and peroxy bonds, was used to synthesize degradable branched polymers under conventional free radical polymerization conditions. The synthesis process was simplified and the cost was reduced by using tert-butyl peroxythioate (isopropylphenyl) ester initiator, and the synthesis of branched and hyperbranched polymers was achieved under conventional conditions.
A highly efficient synthesis of biodegradable branched polymers under conventional free radical polymerization conditions was achieved, with high product yield and purity, reasonable molecular weight distribution, obvious branching structure, good degradation performance, and environmental friendliness.
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Abstract
Description
Technical Field
[0001] This invention relates to peroxide ester initiators containing degradable disulfide bonds, their preparation methods, and their applications in preparing degradable branched polymers, belonging to the fields of organic synthesis and functional initiator design. Background Technology
[0002] Biodegradable (hyper)branched polymers, due to their unique three-dimensional spherical structure, possess properties such as low viscosity, high solubility, and high functionality. Their biodegradability is considered to have wide applications in polymer melt viscosity modifiers, the preparation of high-solids-content coatings and adhesives, drug carriers, catalysts, optoelectronics, new energy, and many other fields. Their broad application prospects have attracted considerable research and attention from experts and scholars both domestically and internationally, making them a popular research direction in polymer science.
[0003] Currently, the main methods for synthesizing vinyl branched polymers include living polymerization and conventional free radical polymerization with chain transfer agents. However, living polymerization has very demanding reaction conditions, high polymerization costs, and a limited range of applicable monomers. Compared to living polymerization, conventional free radical polymerization is simpler and easier to perform, but the reported conventional free radical polymerization systems have complex compositions and require the addition of large amounts of control agents; the synthesized biodegradable branched polymers have low molecular weights and wide molecular weight distributions; the branching points of the products are chemically weak bonds; the branched monomers themselves are extremely unstable; and the rate and extent of the release of branching groups from potential branched monomers are constrained by many factors. Degradation requirements are high, making efficient degradation difficult; vinyl polymers themselves are difficult to degrade, making degradation, recycling, and reuse impossible, which poses a significant environmental hazard. These shortcomings severely restrict the theoretical research and large-scale application of vinyl biodegradable branched polymers.
[0004] The degradation of branched polymers, hyperbranched polymers, graft copolymers, and reactive polymers has significant theoretical and practical value in polymer science and engineering. Synthesizing these specialized structures and degradable polymers under simple conditions is of great importance.
[0005] The pursuit of simplified and inexpensive synthetic methods is an important direction in the research of vinyl biodegradable branched polymers. Designing and synthesizing compounds containing biodegradable disulfide bonds and chemically weak bonds that can homolytically cleave at a suitable rate to initiate free radical polymerization at conventional free radical polymerization temperatures (~80℃) would greatly simplify the synthesis of the aforementioned special-structure biodegradable polymers. To this end, we synthesized a novel biodegradable initiator by combining peroxide ester bonds and lipoic acid disulfide bonds: tert-butyl peroxylipoate (isopropylphenyl). Branched and hyperbranched polymers are novel initiators for conventional free radical polymerization, and can be synthesized through self-initiated polymerization under conventional free radical polymerization conditions. Under appropriate conditions, macromolecular peroxides with peroxide side groups can also be synthesized. Polymers containing peroxide ester bonds can not only initiate polymerization reactions under conventional free radical polymerization conditions to synthesize graft copolymers and comb polymers, but can also be used as reactive compatibilizers for polymer blending and polymer surface grafting modification, while styrene and lipoic acid do not react. Summary of the Invention
[0006] This invention discloses peroxide ester compounds containing degradable disulfide and peroxy bonds. These peroxide ester compounds can be used as novel free radical polymerization initiators. Under conventional free radical polymerization conditions, degradable (hyper)branched polymers were successfully prepared without the addition of branched monomers. The novel free radical initiator of this invention simultaneously contains degradable disulfide and peroxy bonds and exhibits good storage stability. The synthetic method for preparing degradable (hyper)branched polymers is simple, easy to implement, highly operable, low in cost, and yields high purity products.
[0007] To achieve the above objectives, the technical solution adopted by the present invention is as follows:
[0008] The initiator is tert-butyl peroxylipoate (isopropylphenyl) ester, which is synthesized from peroxides containing degradable disulfide bonds. The structural formula of the initiator is:
[0009]
[0010] Where R is -CH3 or .
[0011] The preparation method of the above-mentioned peroxide ester initiator containing degradable disulfide bonds is carried out according to the following steps:
[0012] (1) Add tert-butyl hydrogen peroxide or cumene hydrogen peroxide, catalyst and dehydrating agent to a reaction vessel containing solvent in a molar ratio of 1:0.1:0.11, wherein the mass of the solvent is 1 to 2 times the mass of tert-butyl hydrogen peroxide or cumene hydrogen peroxide, stir evenly to form a mixed solution;
[0013] (2) The above mixed solution is gradually added dropwise to the lipoic acid solution. The amount of lipoic acid is 1 to 1.5 times the amount of tert-butyl hydrogen peroxide or cumene hydrogen peroxide. The reaction temperature is controlled at 15 to 30°C. After the addition is complete, the reaction is stirred for 12 to 24 hours.
[0014] (3) After the reaction was stopped, the system separated into layers. It was washed several times with saturated sodium bicarbonate and 10% hydrochloric acid aqueous solution, and then washed several times with a large amount of distilled water until neutral. An appropriate amount of anhydrous NaSO4 was added for drying, and the solvent was removed by rotary evaporation to obtain the initiator product.
[0015] The solvent in step (1) is dichloromethane, tetrahydrofuran, or trichloromethane.
[0016] The catalyst mentioned in step (1) is 4-dimethylaminopyridine.
[0017] The dehydrating agent mentioned in step (1) is N , N' -Dicyclohexylcarbodiimide or 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide.
[0018] A method for preparing a biodegradable branched polymer is carried out according to the following steps: using a peroxide containing a biodegradable disulfide bond as an initiator and a vinyl monomer as a monomer, a self-initiated free radical polymerization is carried out, wherein the initiator:monomer molar ratio is 1:50~200, wherein the solvent:monomer mass ratio is 0~4:1, the polymerization reaction temperature is controlled at 0~50 °C, and the polymerization reaction time is controlled at 6~48 hours.
[0019] The solvent mentioned is dichloromethane, tetrahydrofuran, or trichloromethane.
[0020] The vinyl monomers mentioned therein are styrene, methacrylic acid monomers, acrylate monomers, acrylic acid derivatives, or vinyl acetate monomers.
[0021] The polymerization system described therein can be a homopolymer or copolymer of vinyl monomers.
[0022] The polymerization method described therein can be bulk polymerization, suspension polymerization, emulsion polymerization or solution polymerization, and the reaction is carried out under conventional polymerization conditions.
[0023] For example, vinyl monomers and peroxide ester initiators containing degradable disulfide bonds are dissolved in a reaction apparatus. After complete dissolution, a distilled aqueous solution of sodium dodecyl sulfate is added, and the mixture is stirred thoroughly until a uniform pale yellow emulsion (pre-emulsification) is obtained. After pre-emulsification, the mixture is stirred in an ice bath, evacuated to remove oxygen, and then purged with argon. Under an argon atmosphere, ferrous sulfate heptahydrate (reducing agent), sodium formaldehyde sulfoxylate (a reducing agent), and disodium ethylenediaminetetraacetate (chelating agent) are added. The reaction is carried out in a constant temperature water bath at 25 °C under anaerobic conditions. After the reaction, a stable emulsion with a bluish tint is obtained. A measured amount of the emulsion is taken, and toluene is used as an external standard. The emulsion is broken with a saturated sodium chloride aqueous solution, and the supernatant is extracted with n-hexane. The monomer conversion rate is determined to be 99%. The remaining sample is demulsified and precipitated in anhydrous ethanol. The polymer product is repeatedly washed with water to remove the emulsifier, and then repeatedly washed with anhydrous ethanol to remove unreacted monomers. The resulting ultra-high molecular weight copolymer is dried in a vacuum oven to constant weight to obtain a polymer with a branched structure.
[0024] Furthermore, the molar ratio of vinyl monomers to ferrous sulfate heptahydrate, sodium formaldehyde sulfoxylate, and disodium ethylenediaminetetraacetate is 50~200:0.01~0.1:0.04~1:0.02~0.5.
[0025] Advantages of this invention: The synthesized initiator raw materials are readily available and have good storage stability. Peroxide compounds with degradable disulfide bonds serve as both initiators and branching monomers, simultaneously possessing degradable properties. No additional initiator or branching monomer is required, and the branching monomer can be endowed with degradable groups. Under conventional free radical polymerization conditions, degradable (hyper)branched polymers can be directly prepared without adding branching monomers. The degree of branching and degradability can be adjusted by regulating the ratio of initiator to monomer. The polymerization reaction conditions are extremely simple, highly operable, and exhibit high monomer conversion rate and high polymer degradability efficiency. Attached Figure Description
[0026] Figure 1 This is the high-performance liquid chromatography (HPLC) spectrum of thiooctanoic acid peroxide containing degradable disulfide bonds prepared in Example 1 of this invention.
[0027] Figure 2 The nuclear magnetic resonance (NMR) of the peroxide thiooctanoate containing degradable disulfide bonds prepared in Example 1 of this invention is shown. 1 1H-NMR spectrum.
[0028] Figure 3 This is the Fourier Transform Infrared (FT-IR) spectrum of thiooctanoic acid peroxide containing degradable disulfide bonds prepared in Example 1 of this invention.
[0029] Figure 4 This is the Raman spectrum of the thiooctanoic acid peroxide containing degradable disulfide bonds prepared in Example 1 of this invention.
[0030] Figure 5 This is the high-performance liquid chromatography (HPLC) spectrum of thiooctanoic acid peroxide containing degradable disulfide bonds prepared in Example 5 of this invention.
[0031] Figure 6 The nuclear magnetic resonance (NMR) of thiooctanoic acid peroxide containing degradable disulfide bonds prepared in Example 5 of this invention is shown. 1 1H-NMR spectrum.
[0032] Figure 7 This is the Fourier Transform Infrared (FT-IR) spectrum of thiooctanoic acid peroxide containing degradable disulfide bonds prepared in Example 5 of this invention.
[0033] Figure 8 This is an application of the molecular weight distribution and Mark-Houwink curve from Example 1.
[0034] Figure 9 The molecular weight distribution and Mark-Houwink curves are used in Examples 2 and 3.
[0035] Figure 10 Examples 5, 6, and 7; and the molecular weight distribution and Mark-Houwink curves in Comparative Example 1.
[0036] Figure 11 This is an application of the molecular weight distribution and Mark-Houwink curve from Example 9.
[0037] Figure 12 This is an application of the molecular weight distribution and Mark-Houwink curve from Example 10. Detailed Implementation
[0038] The technical features of the present invention are further illustrated by the following embodiments, but the scope of protection of the present invention is not limited to the following embodiments.
[0039] Example 1
[0040] Lipoic acid (4.1264 g, 0.02 mol) and 4-dimethylaminopyridine (0.24434 g, 0.002 mol) were dissolved in dichloromethane (DCM) (80 mL), and tert-butyl hydroperoxide (1.8925 g, 0.021 mol) was added, maintaining the temperature at 0–15 °C. After the addition was complete, the mixture was stirred and reacted for 30 min. Then, the solution dissolved in dichloromethane (DCM) (10 mL) was added dropwise. N , N'-Dicyclohexylcarbodiimide (4.3329 g, 0.021 mol) was mixed at 0–15 °C for 30 min, then the reaction temperature was increased to 15–30 °C and the reaction was carried out for 12–20 h. After the reaction was completed, the salt formed in the reaction was removed by filtration, and the product was washed with saturated sodium bicarbonate aqueous solution, 10% hydrochloric acid aqueous solution and distilled water until neutral. The oil phase was separated, dried with anhydrous sodium sulfate, and rotary evaporated to obtain the product tert-butyl thiooctanoate, with an overall yield of 71.8% and a product purity of 97.8%. The structural formula of the product is:
[0041] ;
[0042] tert-butyl peroxide 1 The H-NMR spectrum is shown below. Figure 2 Chemical shift δ The peak at 1.2–1.3 corresponds to the nine hydrogens on the tert-butyl group, and the chemical shift... δ The peaks at 1.4–3.2 ppm correspond to all the hydrogen atoms on the methylene group (—CH2), and the chemical shifts are... δ The peak at 3.5~3.6 corresponds to a hydrogen atom on the pentyl ring.
[0043] Example 2
[0044] Lipoic acid (4.1264 g, 0.02 mol) and 4-dimethylaminopyridine (0.24434 g, 0.002 mol) were dissolved in tetrahydrofuran (THF) (80 mL), and tert-butyl hydroperoxide (1.8925 g, 0.021 mol) was added, maintaining the temperature at 0–15 °C. After the addition was complete, the mixture was stirred and reacted for 30 min. Then, a solution of 10 mL of tetrahydrofuran (THF) was added dropwise. N , N' -Dicyclohexylcarbodiimide (4.3329 g, 0.021 mol) was mixed at 0–15 °C for 30 min, then the reaction temperature was increased to 15–30 °C and the reaction was carried out for 12–20 h. After the reaction was completed, the salt formed in the reaction was removed by filtration, and the product was washed with saturated sodium bicarbonate aqueous solution, 10% hydrochloric acid aqueous solution and distilled water until neutral. The oil phase was separated, dried with anhydrous sodium sulfate, and rotary evaporated to obtain the product tert-butyl thiooctanoate, with a total yield of 80.5% and a product purity of 86.1%. The structural formula of the product is:
[0045] ;
[0046] tert-butyl peroxide 1 Chemical shifts in H-NMR spectra δ The peak at 1.2–1.3 corresponds to the nine hydrogens on the tert-butyl group, and the chemical shift... δThe peaks at 1.4–3.2 ppm correspond to all the hydrogen atoms on the methylene group (—CH2), and the chemical shifts are... δ The peak at 3.5~3.6 corresponds to a hydrogen atom on the pentyl ring.
[0047] Example 3
[0048] Lipoic acid (4.1264 g, 0.02 mol) and 4-dimethylaminopyridine (0.24434 g, 0.002 mol) were dissolved in chloroform (TCM) (80 mL), and tert-butyl hydroperoxide (1.8925 g, 0.021 mol) was added, maintaining the temperature at 0–15 °C. After the addition was complete, the mixture was stirred and reacted for 30 min. Then, the solution dissolved in chloroform (TCM) (10 mL) was added dropwise. N , N' -Dicyclohexylcarbodiimide (4.3329 g, 0.021 mol) was mixed at 0–15 °C for 30 min, then the reaction temperature was increased to 15–30 °C and the reaction was carried out for 12–20 h. After the reaction was completed, the salt formed in the reaction was removed by filtration, and the product was washed with saturated sodium bicarbonate aqueous solution, 10% hydrochloric acid aqueous solution and distilled water until neutral. The oil phase was separated, dried with anhydrous sodium sulfate, and rotary evaporated to obtain the product tert-butyl thiooctanoate, with an overall yield of 78.8% and a product purity of 80.6%. The structural formula of the product is:
[0049] ;
[0050] tert-butyl peroxide 1 Chemical shifts in H-NMR spectra δ The peak at 1.2–1.3 corresponds to the nine hydrogens on the tert-butyl group, and the chemical shift... δ The peaks at 1.4–3.2 ppm correspond to all the hydrogen atoms on the methylene group (—CH2), and the chemical shifts are... δ The peak at 3.5~3.6 corresponds to a hydrogen atom on the pentyl ring.
[0051] Example 4: Lipoic acid (4.1264 g, 0.02 mol) and 4-dimethylaminopyridine (0.24434 g, 0.002 mol) were dissolved in dichloromethane (DCM) (80 mL), and tert-butyl hydroperoxide (1.8925 g, 0.021 mol) was added, with the temperature controlled at 0–15 °C. After the addition was complete, the mixture was stirred for 30 min. Then, 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide (3.2601 g, 0.021 mol) dissolved in dichloromethane (DCM) (10 mL) was added dropwise, and the mixture was stirred for 30 min at 0–15 °C. The reaction temperature was then raised to 15–30 °C, and the reaction was allowed to proceed for 12–20 h. After the reaction was complete, the generated salt was removed by filtration, and the product was washed with saturated sodium bicarbonate aqueous solution, 10% hydrochloric acid aqueous solution, and distilled water until neutral. The oil phase was separated, dried with anhydrous sodium sulfate, and rotary evaporated to obtain the product tert-butyl peroxide, with an overall yield of 81.8% and a purity of 87.8%. The structural formula of the product is:
[0052] ;
[0053] tert-butyl peroxide 1 Chemical shifts in H-NMR spectra δ The peak at 1.2–1.3 corresponds to the nine hydrogens on the tert-butyl group, and the chemical shift... δ The peaks at 1.4–3.2 ppm correspond to all the hydrogen atoms on the methylene group (—CH2), and the chemical shifts are... δ The peak at 3.5~3.6 corresponds to a hydrogen atom on the pentyl ring.
[0054] Example 5: Thioctic acid (4.1264 g, 0.02 mol) and 4-dimethylaminopyridine (0.24434 g, 0.002 mol) were dissolved in dichloromethane (DCM) (80 mL), and cumene hydrogen peroxide (1.8925 g, 0.021 mol) was added, controlling the temperature at 0–15 °C. After the addition was complete, the mixture was stirred and reacted for 30 min. Then, the solution dissolved in dichloromethane (DCM) (10 mL) was added dropwise. N , N' -Dicyclohexylcarbodiimide (4.3329 g, 0.021 mol) was mixed at 0–15 °C for 30 min, then the reaction temperature was increased to 15–30 °C and the reaction was carried out for 12–20 h. After the reaction was completed, the salt generated in the reaction was removed by filtration, and the product was washed with saturated sodium bicarbonate aqueous solution, 10% hydrochloric acid aqueous solution and distilled water until neutral. The oil phase was separated, dried with anhydrous sodium sulfate, and rotary evaporated to obtain the product isopropylphenyl thiooctanoate, with an overall yield of 75.1% and a product purity of 94.8%. The structural formula of the product is:
[0055]
[0056] Signals a and b in δ =7.50 ppm and δ The chemical shift resonance at 7.25 ppm corresponds to the 5-proton hydrogen atom on the phenyl group. The chemical shift resonances of signals c and c′ are at... δ = At 1.70 ppm, it consists of six proton hydrogens on two -CH3 groups, and the signal d is... δ = At 1.85 ppm, the signal corresponds to two proton hydrogens on -CH2-. The chemical shift resonances of signals e, f, and g at 1.59 ppm correspond to six proton hydrogens on -CH2-. Signal h... δ The chemical shift resonance at 3.49 ppm is a proton hydrogen atom on -CH-. The chemical shift resonances of signals i and j are hydrogen atoms on the pentane ring at -CH2-CH2-.
[0057] Application Example 1: Application of the above-mentioned tert-butyl peroxide initiator containing degradable disulfide bonds
[0058] Styrene (St 5.2018 g, 0.05 mol) and tert-butyl thiocarbamate (prepared in Example 1) (0.0695 g, 0.25 mmol) were dissolved in a Schlenk single-necked reaction flask. After complete dissolution, sodium dodecyl sulfate (0.2601 g, 5%) was added. m .St) distilled water (20.8072g, 4 m A solution of .St) was stirred thoroughly until a uniform, pale yellow emulsion (pre-emulsification) was formed. After pre-emulsification, the mixture was stirred in an ice bath, evacuated to remove oxygen, and then purged with argon gas. This process was repeated three times. Then, under an argon atmosphere, the reducing agent ferrous sulfate heptahydrate (FeSO4·7H2O 0.0348 g, 0.125 mmol), the co-reducing agent sodium formaldehyde sulfoxylate (SFS 0.0771 g, 0.50 mmol), and the chelating agent disodium ethylenediaminetetraacetate (EDTA-2Na 0.0841 g, 0.25 mmol) were added. The reaction was carried out in an anaerobic environment at a constant temperature of 25 °C for 8 hours. After the reaction, a stable emulsion with a bluish tint was obtained. A measured amount of the emulsion was taken, and using toluene as an external standard, the emulsion was broken with a saturated sodium chloride aqueous solution. The supernatant was extracted with n-hexane, and the monomer conversion rate was determined to be 99%. The remaining sample was demulsified and precipitated in anhydrous ethanol. The polymerization product was repeatedly washed with water to remove the emulsifier, and then the resulting polymer was repeatedly washed with anhydrous ethanol to remove unreacted monomers, finally yielding ultra-high molecular weight styrene. co The tert-butyl perthioate copolymer was dried in a vacuum oven at 30 °C to constant weight, yielding a white solid powder. The molecular weight of the resulting branched polystyrene with disulfide bonds in the main chain was [missing information]. M n. SEC = 61000 g / mol Mw. MALLS =328000 g / mol, molecular weight distribution is Ð = 3.9, g =0.522, which proves that the obtained polymer has a branched structure.
[0059] Application Example 2: Application of the above-mentioned tert-butyl peroxide initiator containing degradable disulfide bonds;
[0060] Vinyl acetate (VA) C 4.2045 g (0.05 mol) and tert-butyl peroxythioate (0.0695 g, 0.25 mmol) were dissolved in a Schlenk single-necked reaction flask. After complete dissolution, sodium dodecyl sulfate (0.2102 g, 5%) was added. m VA C ) distilled water (16.8180g, 4) m VA C The solution was stirred thoroughly until a uniform, pale yellow emulsion (pre-emulsification) was formed. After pre-emulsification, the mixture was stirred in an ice bath, evacuated to remove oxygen, and then purged with argon gas. This process was repeated three times. Then, under an argon atmosphere, the reducing agent ferrous sulfate heptahydrate (FeSO4·7H2O 0.0139 g, 0.05 mmol), the co-reducing agent sodium formaldehyde sulfoxylate (SFS 0.0236 g, 0.20 mmol), and the chelating agent disodium ethylenediaminetetraacetate (EDTA-2Na 0.0336 g, 0.10 mmol) were added. The reaction was carried out in an anaerobic environment at a constant temperature of 25 °C for 24 h. After the reaction, a stable emulsion with a bluish tint was obtained. A measured amount of the emulsion was taken, and using toluene as an external standard, the emulsion was broken with a saturated sodium chloride aqueous solution. The supernatant was extracted with n-hexane, and the monomer conversion rate was determined to be 99%. The remaining sample was demulsified and precipitated in anhydrous ethanol. The polymerization product was repeatedly washed with water to remove the emulsifier, and then the resulting polymer was repeatedly washed with anhydrous ethanol to remove unreacted monomers, finally yielding ultra-high molecular weight styrene. co - The tert-butyl thiooctanoate peroxide copolymer was dried in a vacuum oven at 30 °C to constant weight, yielding a white solid powder. The molecular weight of the resulting branched polystyrene with disulfide bonds in the main chain was [missing information]. M n. SEC = 61000 g / mol M w. MALLS =93000 g / mol, molecular weight distribution is Ð = 4.2, g = 0.916, proving that the obtained polymer has a branched structure.
[0061] Application Example 3: Application of the above-mentioned tert-butyl peroxide initiator containing degradable disulfide bonds;
[0062] Vinyl acetate (VA) C 4.2045 g (0.05 mol) and tert-butyl peroxythioate (prepared in Example 1) (0.1390 g, 0.50 mmol) were dissolved in a Schlenk single-necked reaction flask. After complete dissolution, sodium dodecyl sulfate (0.2102 g, 5%) was added. m VA C ) distilled water (16.8180g, 4) m VA C The solution was stirred thoroughly until a uniform, pale yellow emulsion (pre-emulsification) was formed. After pre-emulsification, the mixture was stirred in an ice bath, evacuated to remove oxygen, and then purged with argon gas. This process was repeated three times. Then, under an argon atmosphere, the reducing agent ferrous sulfate heptahydrate (FeSO4·7H2O 0.0139 g, 0.05 mmol), the co-reducing agent sodium formaldehyde sulfoxylate (SFS 0.0236 g, 0.20 mmol), and the chelating agent disodium ethylenediaminetetraacetate (EDTA-2Na 0.0336 g, 0.10 mmol) were added. The reaction was carried out in an anaerobic environment at a constant temperature of 25 °C for 24 h. After the reaction, a stable emulsion with a bluish tint was obtained. A measured amount of the emulsion was taken, and using toluene as an external standard, the emulsion was broken with a saturated sodium chloride aqueous solution. The supernatant was extracted with n-hexane, and the monomer conversion rate was determined to be 99%. The remaining sample was demulsified and precipitated in anhydrous ethanol. The polymerization product was repeatedly washed with water to remove the emulsifier, and then the resulting polymer was repeatedly washed with anhydrous ethanol to remove unreacted monomers, finally yielding ultra-high molecular weight styrene. co The tert-butyl perthioate copolymer was dried in a vacuum oven at 30 °C to constant weight, yielding a white solid powder. The molecular weight of the resulting branched polystyrene with disulfide bonds in the main chain was [missing information]. M n. SEC = 143000 g / mol, M w. MALLS =160000 g / mol, molecular weight distribution is Ð =3.8, g = 0.878, proving that the obtained polymer has a branched structure.
[0063] Application Example 4: Application of the above-mentioned isopropylphenyl thiocarboxylate initiator containing degradable disulfide bonds.
[0064] Styrene (St 5.2018 g, 0.05 mol) and isopropylphenyl thiooctanoate (0.0886 g, 0.25 mmol) were dissolved in a Schlenk single-necked reaction flask. After complete dissolution, the mixture was evacuated to remove oxygen and then purged with argon gas. This process was repeated three times. The mixture was then reacted in a 70°C oil bath for 8 hours. Gas chromatography showed a monomer conversion rate of 92.6%. The resulting polymer, after precipitation in ethanol, was dried in a 30°C vacuum oven to constant weight, yielding a white solid powder. The molecular weight was determined to be...M n. SEC =34000 g / mol M w. MALLS =175000 g / mol, molecular weight distribution is Ð = 3.9, g The value of ´ = 0.732 proves that the obtained polymer has a branched structure.
[0065] Application Example 5
[0066] Styrene (St 2.6038g, 0.025mol), butyl acrylate ( n -BA 3.2042g, 0.025mol) and tert-butyl peroxythioate (0.0695g, 0.25mmol) were dissolved in a Schlenk single-necked reaction flask. After complete dissolution, a solution of sodium dodecyl sulfate (0.2601g, 5%M) in distilled water (20.8072g, 4M) was added, and the mixture was stirred thoroughly until a uniform pale yellow emulsion (pre-emulsification) was formed. After pre-emulsification, the mixture was stirred in an ice bath, evacuated to remove oxygen, and then purged with argon. This process was repeated three times. Then, under an argon atmosphere, the reducing agent ferrous sulfate heptahydrate (FeSO4·7H2O 0.0348g, 0.125mmol), the co-reducing agent sodium formaldehyde sulfoxylate (SFS 0.0771g, 0.50mmol), and the chelating agent disodium ethylenediaminetetraacetate (EDTA-2Na 0.0841g, 0.25mmol) were added. The mixture was reacted in an anaerobic environment in a constant temperature water bath at 25 °C for 8 hours. After the reaction, a stable emulsion with a bluish tint was obtained. A measured amount of the emulsion was demulsified with saturated sodium chloride aqueous solution using toluene as an external standard. The supernatant was extracted with n-hexane, and the polymer styrene conversion rate was determined to be 99%, and the butyl acrylate conversion rate was 99%. The remaining sample was demulsified and precipitated in anhydrous ethanol. The polymer product was repeatedly washed with water to remove the emulsifier, and then repeatedly washed with anhydrous ethanol to remove unreacted monomers, finally yielding ultra-high molecular weight styrene- co The butyl acrylate copolymer was dried in a vacuum oven at 30 °C to constant weight, yielding a white solid powder. The molecular weight of the resulting branched polystyrene with disulfide bonds in the main chain was [missing information]. M n. SEC = 124000 g / mol, M w. MALLS =472000 g / mol, molecular weight distribution is Ð = 4.7, g The value of ´ = 0.990 proves that the obtained polymer has a branched structure.
[0067] Application Example 6
[0068] Styrene (St 2.6038g, 0.025mol), butyl acrylate (n -BA 3.2042g, 0.025mol) and tert-butyl peroxythioate (0.0695g, 0.25mmol) were dissolved in a Schlenk single-necked reaction flask. After complete dissolution, a solution of sodium dodecyl sulfate (0.2601g, 5%M) in distilled water (20.8072g, 4M) was added, and the mixture was stirred thoroughly until a uniform pale yellow emulsion (pre-emulsification) was formed. After pre-emulsification, the mixture was stirred in an ice bath, evacuated to remove oxygen, and then purged with argon. This process was repeated three times. Then, under an argon atmosphere, the reducing agent ferrous sulfate heptahydrate (FeSO4·7H2O 0.0139g, 0.05mmol), the co-reducing agent sodium formaldehyde sulfoxylate (SFS 0.0336g, 0.20mmol), and the chelating agent disodium ethylenediaminetetraacetate (EDTA-2Na 0.0841g, 0.10mmol) were added. The mixture was reacted in an anaerobic environment in a constant temperature water bath at 25 °C for 8 hours. After the reaction, a stable emulsion with a bluish tint was obtained. A measured amount of the emulsion was demulsified with saturated sodium chloride aqueous solution using toluene as an external standard. The supernatant was extracted with n-hexane, and the polymer styrene conversion rate was determined to be 99%, and the butyl acrylate conversion rate was 99%. The remaining sample was demulsified and precipitated in anhydrous ethanol. The polymer product was repeatedly washed with water to remove the emulsifier, and then repeatedly washed with anhydrous ethanol to remove unreacted monomers, finally yielding ultra-high molecular weight styrene- co The butyl acrylate copolymer was dried in a vacuum oven at 30 °C to constant weight, yielding a white solid powder. The molecular weight of the resulting branched polystyrene with disulfide bonds in the main chain was [missing information]. M n. SEC = 162000 g / mol, M w. MALLS =781000 g / mol, molecular weight distribution is Ð = 8.0, g = 0.970, which proves that the obtained polymer has a branched structure.
[0069] Application Example 7: Styrene (St 2.6038g, 0.025mol), butyl acrylate ( n-BA 3.2042g, 0.025mol) and tert-butyl peroxythioate (0.0695g, 0.25mmol) were dissolved in a Schlenk single-necked reaction flask. After complete dissolution, a solution of sodium dodecyl sulfate (0.2601g, 5%M) in distilled water (20.8072g, 4M) was added, and the mixture was stirred thoroughly until a uniform pale yellow emulsion (pre-emulsification) was formed. After pre-emulsification, the mixture was stirred in an ice bath, evacuated to remove oxygen, and then purged with argon. This process was repeated three times. Then, under an argon atmosphere, the reducing agent ferrous sulfate heptahydrate (FeSO4·7H2O 0.0014g, 0.005mmol), the co-reducing agent sodium formaldehyde sulfoxylate (SFS 0.0024g, 0.02mmol), and the chelating agent disodium ethylenediaminetetraacetate (EDTA-2Na 0.0034g, 0.01mmol) were added. The mixture was reacted in an anaerobic environment in a constant temperature water bath at 25 °C for 24 h. After the reaction, a stable emulsion with a bluish tint was obtained. A measured amount of the emulsion was demulsified with saturated sodium chloride aqueous solution using toluene as an external standard. The supernatant was extracted with n-hexane, and the polymer styrene conversion rate was determined to be 99%, and the butyl acrylate conversion rate was 99%. The remaining sample was demulsified and precipitated in anhydrous ethanol. The polymer product was repeatedly washed with water to remove the emulsifier, and then repeatedly washed with anhydrous ethanol to remove unreacted monomers, finally yielding ultra-high molecular weight styrene- co The butyl acrylate copolymer was dried in a vacuum oven at 30 °C to constant weight, yielding a white solid powder. The molecular weight of the resulting branched polystyrene with disulfide bonds in the main chain was [missing information]. M n. SEC = 273000 g / mol, M w. MALLS =1023000 g / mol, molecular weight distribution is Ð = 11.3, g = 0.906, proving that the obtained polymer has a branched structure.
[0070] Application Example 8: Application of the above-mentioned tert-butyl peroxide initiator containing degradable disulfide bonds
[0071] Acrylonitrile (AN 1.3266 g, 0.025 mol), isooctyl acrylate (2-EHA 4.6070 g, 0.025 mol), and tert-butyl thiooctanoate peroxide (0.0695 g, 0.25 mmol) were dissolved in a Schlenk single-necked reaction flask. After complete dissolution, a solution of sodium dodecyl sulfate (0.2601 g, 5% M) in distilled water (20.8072 g, 4 M) was added, and the mixture was stirred thoroughly until a uniform pale yellow emulsion (pre-emulsification) was formed. After pre-emulsification, the mixture was stirred in an ice bath, evacuated to remove oxygen, and then purged with argon gas. This process was repeated three times. Then, under an argon atmosphere, the reducing agent ferrous sulfate heptahydrate (FeSO4·7H2O 0.0348 g, 0.125 mmol) and the co-reducing agent sodium formaldehyde sulfoxylate (SFS) were added. 0.0771 g (0.50 mmol) of ethylenediaminetetraacetic acid disodium salt (EDTA-2Na 0.0841 g (0.25 mmol)) and chelating agent were added. The reaction was carried out in a constant temperature water bath at 25 °C for 8 h under anaerobic conditions. After the reaction, a stable emulsion with a bluish tint was obtained. A quantitative amount of the emulsion was taken, and with toluene as an external standard, it was demulsified with saturated sodium chloride aqueous solution. The supernatant was extracted with n-hexane, and the conversion rate of acrylonitrile and isooctyl acrylate was determined to be 99%. The remaining sample was demulsified and precipitated in anhydrous ethanol. The polymer product was repeatedly washed with water to remove the emulsifier, and then repeatedly washed with anhydrous ethanol to remove unreacted monomers. The final product was ultra-high molecular weight acrylonitrile- co - The isooctyl acrylate copolymer was dried in a vacuum oven at 30 °C to constant weight, yielding a white solid powder. The molecular weight of the resulting branched polystyrene with disulfide bonds in the main chain was [missing information]. M n. SEC = 233000 g / mol, M w. MALLS =361000 g / mol, molecular weight distribution is Ð = 11.3.
[0072] Application Example 9: Application of the above-mentioned tert-butyl peroxide initiator containing degradable disulfide bonds
[0073] Styrene (St 2.6038g, 0.025mol), butyl acrylate ( n-BA 3.2042 g, 0.025 mol) and tert-butyl peroxythioate (0.0695 g, 0.25 mmol) were dissolved in a Schlenk single-necked reaction flask. After complete dissolution, a solution of sodium dodecyl sulfate (0.2601 g, 5% M) in distilled water (20.8072 g, 4 M) was added, and the mixture was stirred thoroughly until a uniform pale yellow emulsion (pre-emulsification) was formed. After pre-emulsification, the mixture was stirred in an ice bath, evacuated to remove oxygen, and then purged with argon. This process was repeated three times. Then, under an argon atmosphere, the reducing agent ferrous sulfate heptahydrate (FeSO4·7H2O 0.0014 g, 0.005 mmol), the co-reducing agent sodium formaldehyde sulfoxylate (SFS 0.0024 g, 0.02 mmol), and the chelating agent disodium ethylenediaminetetraacetate (EDTA-2Na 0.0034 g, 0.01 mmol) were added. The mixture was reacted in an anaerobic environment in a constant temperature water bath at 25 °C for 24 h. After the reaction, a stable emulsion with a bluish tint was obtained. A measured amount of the emulsion was demulsified with saturated sodium chloride aqueous solution using toluene as an external standard. The supernatant was extracted with n-hexane, and the polymer styrene conversion rate was determined to be 99%, and the butyl acrylate conversion rate was 99%. The remaining sample was demulsified and precipitated in anhydrous ethanol. The polymer product was repeatedly washed with water to remove the emulsifier, and then repeatedly washed with anhydrous ethanol to remove unreacted monomers, finally yielding ultra-high molecular weight styrene- co The butyl acrylate copolymer was dried in a vacuum oven at 30 °C to constant weight, yielding a white solid powder. The molecular weight of the resulting branched polystyrene with disulfide bonds in the main chain was [missing information]. M n. SEC = 273000 g / mol, M w. MALLS =1023000 g / mol, molecular weight distribution is Ð = 11.3, g The value ´ = 0.906, proving that the obtained polymer has a branched structure. Polystyrene- co - Butyl acrylate (0.05 g) and dioxane (5.00 g) were stirred at a suitable speed for a period of time until fully dissolved. Then, dithiothreitol (0.01 g) was added and stirred thoroughly until dissolved. The mixture was sealed and reacted in a constant temperature oil bath at 30 °C for a certain period of time. The reaction solution was a turbid yellow liquid with the precipitation of a yellow solid. After the reaction, the sample was passed through a neutral alumina column and precipitated in anhydrous ethanol. Finally, the degraded polymer was dried in a vacuum oven at 30 °C to constant weight. The molecular weight of the degraded polymer was Mn. SEC = 251000 g / mol, Mw. MALLS = 742000 g / mol, with a molecular weight distribution of ε = 11.3 and g' = 1.000. The molecular weight of the degraded polymer was significantly reduced. Figure 11 As shown.
[0074] Application Example 10: Application of the above-mentioned tert-butyl peroxide initiator containing degradable disulfide bonds
[0075] Styrene (St 2.6038g, 0.025mol), butyl acrylate ( n -BA 3.2042g, 0.025mol) and tert-butyl peroxythioate (0.4170g, 1.50mmol) were dissolved in a Schlenk single-necked reaction flask. After complete dissolution, a solution of sodium dodecyl sulfate (0.2601g, 5%M) in distilled water (20.8072g, 4M) was added, and the mixture was stirred thoroughly until a uniform pale yellow emulsion (pre-emulsification) was formed. After pre-emulsification, the mixture was stirred in an ice bath, evacuated to remove oxygen, and then purged with argon. This process was repeated three times. Then, under an argon atmosphere, the reducing agent ferrous sulfate heptahydrate (FeSO4·7H2O 0.0014g, 0.005mmol), the co-reducing agent sodium formaldehyde sulfoxylate (SFS 0.0024g, 0.02mmol), and the chelating agent disodium ethylenediaminetetraacetate (EDTA-2Na 0.0034g, 0.01mmol) were added. The mixture was reacted in an anaerobic environment in a constant temperature water bath at 25 °C for 24 h. After the reaction, a stable emulsion with a bluish tint was obtained. A measured amount of the emulsion was demulsified with saturated sodium chloride aqueous solution using toluene as an external standard. The supernatant was extracted with n-hexane, and the polymer styrene conversion rate was determined to be 99%, and the butyl acrylate conversion rate was 99%. The remaining sample was demulsified and precipitated in anhydrous ethanol. The polymer product was repeatedly washed with water to remove the emulsifier, and then repeatedly washed with anhydrous ethanol to remove unreacted monomers, finally yielding ultra-high molecular weight styrene- co The butyl acrylate copolymer was dried in a vacuum oven at 30 °C to constant weight, yielding a white solid powder. The resulting branched polystyrene with disulfide bonds in its main chain... co -The molecular weight of butyl acrylate is M n. SEC = 259000 g / mol, M w. MALLS =1074000 g / mol, molecular weight distribution is Ð = 7.2, g The value of ´ = 0.870 proves that the obtained polymer has a branched structure. Polystyrene- co- Butyl acrylate (0.05 g) and dioxane (5.00 g) were stirred at a suitable speed for a period of time until fully dissolved. Then, dithiothreitol (0.01 g) was added and stirred thoroughly until dissolved. The mixture was sealed and reacted in a constant temperature oil bath at 30 °C for a certain period of time. The reaction solution was a turbid yellow liquid with the precipitation of a yellow solid. After the reaction was completed, the sample was passed through a neutral alumina column and precipitated in anhydrous ethanol. Finally, the obtained degraded polymer was dried in a vacuum oven at 30 °C until constant weight. The molecular weight of the obtained degraded polymer was [missing value]. M n. SEC = 79000 g / mol M w. MALLS =253000 g / mol, molecular weight distribution is Ð = 3.4, g =1.000. The molecular weight of the resulting polymers decreased significantly after degradation. For example... Figure 12 As shown.
[0076] Comparative Example 1
[0077] Styrene (St 2.6038g, 0.025mol), butyl acrylate ( n -BA 3.2042 g, 0.025 mol) and tert-butyl hydroperoxide (0.0225 g, 0.25 mmol) were dissolved in a Schlenk single-necked reaction flask. After complete dissolution, a solution of sodium dodecyl sulfate (0.2601 g, 5% M) in distilled water (20.8072 g, 4 M) was added, and the mixture was stirred thoroughly until a uniform pale yellow emulsion (pre-emulsification) was formed. After pre-emulsification, the mixture was stirred in an ice bath, evacuated to remove oxygen, and then purged with argon. This process was repeated three times. Then, under an argon atmosphere, the reducing agent ferrous sulfate heptahydrate (FeSO4·7H2O 0.0014 g, 0.005 mmol), the co-reducing agent sodium formaldehyde sulfoxylate (SFS 0.0024 g, 0.02 mmol), and the chelating agent disodium ethylenediaminetetraacetate (EDTA-2Na 0.0034 g, 0.01 mmol) were added. The mixture was reacted in an anaerobic environment in a constant temperature water bath at 25 °C for 24 h. After the reaction, a stable emulsion with a bluish tint was obtained. A measured amount of the emulsion was demulsified with saturated sodium chloride aqueous solution using toluene as an external standard. The supernatant was extracted with n-hexane, and the polymer styrene conversion rate was determined to be 99%, and the butyl acrylate conversion rate was 99%. The remaining sample was demulsified and precipitated in anhydrous ethanol. The polymer product was repeatedly washed with water to remove the emulsifier, and then repeatedly washed with anhydrous ethanol to remove unreacted monomers, finally yielding ultra-high molecular weight styrene- co The butyl acrylate copolymer was dried in a vacuum oven at 30 °C to constant weight, yielding a white solid powder. The molecular weight of the resulting branched polystyrene with disulfide bonds in the main chain was [missing information]. M n. SEC= 104000 g / mol, M w. MALLS =323000 g / mol, molecular weight distribution is Ð = 3.6, the molecular weight distribution is unimodal and symmetrical, proving the polymer's unbranched structure. For example... Figure 10 As shown.
[0078] polystyrene- co - Butyl acrylate (0.05 g) and dioxane (5.00 g) were stirred at a suitable speed for a period of time until fully dissolved. Then, dithiothreitol (0.01 g) was added and stirred thoroughly until dissolved. The mixture was sealed and reacted in a constant temperature oil bath at 30 °C for a certain period of time. The reaction solution was a turbid yellow liquid with the precipitation of a yellow solid. After the reaction was completed, the sample was passed through a neutral alumina column and precipitated in anhydrous ethanol. Finally, the obtained degraded polymer was dried in a vacuum oven at 30 °C to constant weight. The absence of change in the molecular weight of the obtained polymer proves that it cannot be degraded.
[0079] The above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.
Claims
1. A peroxide ester initiator containing degradable disulfide bonds, characterized in that, The structural formula of the initiator is: Where R is -CH3 or 2. The application of the peroxide ester initiator containing degradable disulfide bonds as described in claim 1 in the preparation of degradable branched polymers, characterized in that, Using a peroxide ester initiator containing degradable disulfide bonds, and vinyl monomers as monomers, a free radical polymerization reaction is initiated in a solvent to synthesize a degradable branched polymer.
3. The application of the peroxide ester initiator containing degradable disulfide bonds as described in claim 2 in the preparation of degradable branched polymers, characterized in that, The molar ratio of the initiator to the vinyl monomer is 1:50 to 200, and the mass ratio of the solvent to the monomer is 0 to 4:
1.
4. The application of the peroxide ester initiator containing degradable disulfide bonds as described in claim 2 in the preparation of degradable branched polymers, characterized in that, The polymerization reaction temperature is controlled between 0 and 50°C, and the polymerization reaction time is controlled between 6 and 48 hours.
5. The application of the peroxide ester initiator containing degradable disulfide bonds as described in claim 2 in the preparation of degradable branched polymers, characterized in that, The solvent is dichloromethane, tetrahydrofuran, or trichloromethane.
6. The application of the peroxide ester initiator containing degradable disulfide bonds as described in claim 2 in the preparation of degradable branched polymers, characterized in that, The vinyl monomers mentioned are styrene, methacrylic acid monomers, acrylate monomers, acrylic acid derivatives, or vinyl acetate monomers.
7. The application of the peroxide ester initiator containing degradable disulfide bonds as described in claim 2 in the preparation of degradable branched polymers, characterized in that, The polymerization reaction system is a homopolymer or copolymer of vinyl monomers.