Preparation method of tert-butylperoxy-2-ethylhexyl carbonate with high active oxygen content

Abstract

The invention relates to the technical field of organic synthesis, in particular to a preparation method of tertiary butylperoxy-2-ethylhexyl carbonate with high active oxygen content. The invention overcomes the problems of low active oxygen content and low yield of the product in the prior art. The preparation method comprises the following steps: firstly, carrying out inclusion stabilization on tert-butyl hydroperoxide by using methyl-beta-cyclodextrin to construct a premixed solution; then introducing a modified catalyst into a composite solvent environment composed of isododecane and hydrofluoroether, and dropwise adding chloroformic acid-2-ethylhexyl ester through a low-temperature high-shear process to complete the reaction; and finally, carrying out solid-phase adsorption impurity removal by utilizing the modified hydrotalcite, and distilling to obtain the tert-butylperoxy-2-ethylhexyl carbonate. According to the method, interface heat and mass transfer is improved through the composite solvent, the reaction rate is increased through high-activity sites of the modified catalyst, anhydrous deacidification and dechlorination are achieved in cooperation with the modified hydrotalcite, raw material hydrolysis and peroxide bond thermal decomposition are effectively inhibited through the synergistic process, and the method has excellent industrial application value.

Description

Technical Field

[0001] This invention relates to the field of organic synthesis technology, specifically to a method for preparing tert-butylperoxy-2-ethylhexane carbonate with high reactive oxygen content. Background Technology

[0002] tert-butylperoxy-2-ethylhexane carbonate is a highly efficient, low-volatile organic peroxide widely used as a polymerization initiator for monomers such as ethylene, styrene, and acrylates, as well as a curing agent for unsaturated polyesters. Its molecular structure contains a peroxide bond and a carbonate group, giving it an excellent balance between thermal stability and initiation activity. In industrial applications, high-purity tert-butylperoxy-2-ethylhexane carbonate not only increases polymerization rates but also significantly reduces residual odor and yellowing in polymer products, making it a key additive in the production of high-end optical-grade resins and food-contact-grade plastics.

[0003] Despite the wide applications of tert-butylperoxide-2-ethylhexyl carbonate, its industrial preparation faces two major bottlenecks: difficulty in increasing the reactive oxygen species content and unstable reaction yield. Traditional processes often involve the reaction of tert-butyl hydrogen peroxide with 2-ethylhexyl chloroformate under alkaline conditions. However, 2-ethylhexyl chloroformate readily undergoes hydrolysis in a strongly alkaline aqueous phase, generating impurities composed of 2-ethylhexanol and carbon dioxide. This not only directly reduces the yield but also, due to emulsification, encapsulates the reactants, hindering the main reaction. Furthermore, excessively high local alkali concentrations and delayed removal of reaction heat can lead to the thermal decomposition of sensitive peroxide bonds, making it difficult to stabilize the reactive oxygen species content of the final product.

[0004] To this end, a method for preparing tert-butylperoxy-2-ethylhexane carbonate with high reactive oxygen content was proposed. Summary of the Invention

[0005] The purpose of this invention is to design a method for preparing tert-butylperoxy-2-ethylhexane carbonate with high active oxygen content. This invention first utilizes methyl-β-cyclodextrin to include and stabilize tert-butyl hydrogen peroxide, constructing a premixed solution. Then, a modified catalyst is introduced into a composite solvent environment composed of isododecane and hydrofluoroether, and the reaction is completed by dropwise addition of 2-ethylhexyl chloroformate using a low-temperature, high-shear process. Finally, modified hydrotalcite is used for solid-phase adsorption to remove impurities, and tert-butylperoxy-2-ethylhexane carbonate is obtained by distillation. This invention improves interfacial heat and mass transfer through a composite solvent, enhances the reaction rate by utilizing the high active sites of the modified catalyst, and achieves anhydrous deacidification and dechlorination in conjunction with modified hydrotalcite. This synergistic process effectively inhibits the hydrolysis of raw materials and the thermal decomposition of peroxy bonds.

[0006] To achieve the above objectives, the present invention provides the following technical solution: Unless otherwise specified, all the following parts are by weight.

[0007] This invention provides a method for preparing tert-butylperoxy-2-ethylhexane carbonate with high reactive oxygen content, comprising the following steps:

[0008] A premixed solution was prepared by mixing potassium hydroxide solution, methyl-β-cyclodextrin, and tert-butyl hydrogen peroxide solution. A composite solvent, a modified catalyst, and 2-ethylhexyl chloroformate were added to the premixed solution, and the reaction was allowed to mature to obtain a reaction mixture. The reaction mixture was then treated with modified hydrotalcite to obtain tert-butyl peroxide-2-ethylhexyl carbonate. The composite solvent was prepared by mixing isododecane and hydrofluoroether. The modified catalyst was prepared by hyperbranched polyglycidyl ether, potassium hydroxide, 1,2-epoxydodecane, and 2,3-epoxypropyltrimethylammonium chloride.

[0009] Preferably, the premixed solution is prepared as follows: In a reactor equipped with a cryogenic jacket and a high-shear dispersion disk (the ratio of the dispersion disk diameter to the reactor diameter is 1:3), add 60 parts of 45% potassium hydroxide solution and 0.1-0.3 parts of methyl-β-cyclodextrin (average degree of substitution is 1.8, CAS number: 128446-36-6), start low-speed stirring (150 rpm), lower the reactor temperature to 5°C, slowly add 66-70 parts of 70% tert-butyl hydrogen peroxide solution, control the dropping rate so that the internal temperature does not exceed 8°C, after the dropping is completed, keep at 6°C and stir for 20 min to obtain the premixed solution.

[0010] Preferably, the reaction mixture is prepared as follows: 160-200 parts of composite solvent and 0.5-0.8 parts of modified catalyst are added to the premixed solution, high-shear stirring is started, the speed is increased to 1300 rpm, and it is continued for 10 min to obtain a composite emulsion; the coolant in the reactor jacket is adjusted to control the temperature inside the reactor at 10℃±1℃, and 95-105 parts of 2-ethylhexyl chloroformate are added dropwise through a precision metering pump, with the dropper tip inserted below the liquid surface (subsurface feeding), and the dropping time is 85 min. The stirring speed is maintained at 9000 rpm (the pH of the aqueous phase is checked to ensure that the final pH is >9.0). After the dropping is completed, the temperature is slowly raised to 20℃, and the mixture is kept warm and stirred for 25-35 min to obtain the reaction mixture.

[0011] Preferably, the modified catalyst is prepared as follows: 95-105 parts of hyperbranched polyglycidyl ether and 160 parts of isopropanol are added to a four-necked flask, heated to 50°C and stirred to dissolve. 1.5 parts of potassium hydroxide are added and stirred for 30 min to obtain an activation solution. The activation solution is heated to 80°C, and 38-42 parts of 1,2-epoxydodecane are slowly added dropwise through a constant-pressure dropping funnel over a time controlled at 1 h. After the addition is complete, the mixture is refluxed at 80°C for 4 h to obtain the reaction system. The reaction system is then kept... At 80℃, an isopropanol solution containing 2,3-epoxypropyltrimethylammonium chloride (80 parts of 2,3-epoxypropyltrimethylammonium chloride dissolved in 120 parts of isopropanol) was added dropwise over 1.5 hours. After the addition was complete, the temperature was raised to 80℃ and the reaction continued for 6 hours. After the reaction was completed, most of the isopropanol was removed by vacuum distillation. The remaining viscous liquid was poured into 1000 parts of cold acetone to precipitate and remove unreacted small molecule monomers. The solid was collected by filtration and dried in a vacuum oven at 50℃ for 12 hours to obtain the modified catalyst.

[0012] The preferred method for preparing hyperbranched polyglycidyl ether is as follows: 13.4 parts of trimethylolpropane are added to a reaction vessel, and 3 parts of potassium methoxide are added. The mixture is stirred for 30 minutes under vacuum and at 60°C. The generated methanol is removed by vacuum distillation to obtain an activated initiator system. The reaction system is heated to 95°C, and 185 parts of glycidyl ether are slowly added dropwise through a precision metering pump under vigorous stirring. The dropwise addition process needs to be continued for 14 hours. After the dropwise addition is completed, the reaction is continued at 95°C for 3 hours. After the reaction is completed, the product is dissolved in methanol, and potassium ions are neutralized and removed by passing it through a cation exchange resin column (D001). Methanol is removed by rotary evaporation, and the product is dried under vacuum at 80°C for 24 hours to obtain hyperbranched polyglycidyl ether (weight average molecular weight of 1500-2500, hydroxyl value of 13-14 mmol / g).

[0013] Preferably, the composite solvent includes isododecane and hydrofluoroether (HFE-7100, boiling point 61°C), and the weight ratio of isododecane to hydrofluoroether is 3-5:1.

[0014] Preferably, the post-treatment process is as follows: stop stirring, allow to stand for 15-25 minutes to separate and remove the high-salt water phase (containing KCl and excess alkali), add 2-3 parts of modified hydrotalcite to the oil phase retained in the reactor, start medium-speed stirring (300 rpm), and adsorb at 25°C for 15-25 minutes to obtain an oil phase mixture; pump the oil phase mixture into a plate and frame filter press (with 1 μm filter cloth) to filter out the modified hydrotalcite that has adsorbed impurities, and obtain the filtrate; pass the filtrate through a filter press packed with a strongly acidic cation exchanger. The modified catalyst is removed from the adsorption column of molecular exchange resin (D001) and recycled. The effluent is collected. The effluent enters a short-path molecular distillation apparatus. The evaporation surface temperature is 30-40℃, the system pressure is <50Pa (high vacuum), and the scraper speed is 300rpm. The light components (isododecane, HFE-7100, tert-butanol, and trace water) are condensed and recovered from the top (can be recycled). The heavy components (tert-butylperoxy-2-ethylhexane carbonate) are discharged from the bottom. After filtration through a 0.2μm filter, the product is filled into bottles.

[0015] Preferably, the modified hydrotalcite is prepared as follows: 150 parts magnesium nitrate and 75 parts aluminum nitrate are dissolved in 400 parts deionized water to prepare solution A; 60 parts sodium hydroxide and 20 parts sodium carbonate are dissolved in 400 parts deionized water to prepare solution B; under vigorous stirring, solutions A and B are simultaneously added dropwise to a reactor containing 200 parts deionized water, with the addition time controlled at 1.5 hours, maintaining the pH of the system at approximately 9.5. After the addition is complete, the resulting white slurry is heated to 65°C, filtered, and the filter cake is repeatedly washed with deionized water until the pH of the washing liquid is neutral. The filter cake was dried in an oven at 100℃ for 12 hours and then ground to obtain a hydrotalcite precursor. The hydrotalcite precursor was placed in a muffle furnace and heated to 440-460℃ at a heating rate of 5℃ / min, and calcined at this temperature for 3-5 hours to obtain calcined hydrotalcite. 5 parts of sodium stearate were added to 105 parts of deionized water, heated to 80℃ and stirred until the sodium stearate was completely dissolved to form a sodium stearate solution. The calcined hydrotalcite was dispersed in 150 parts of anhydrous ethanol, the sodium stearate solution was added, and the mixture was stirred and refluxed at 70℃ for 1.5 hours. After filtration, washing, and vacuum drying, modified hydrotalcite was obtained.

[0016] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0017] 1. This invention employs a hyperbranched polyglycidyl ether, doubly modified with 1,2-epoxydodecane and 2,3-epoxypropyltrimethylammonium chloride, as a phase transfer catalyst. Unlike traditional quaternary ammonium salts with a single active center, this catalyst possesses high active sites. Furthermore, the introduction of C12 long-chain alkyl groups endows it with excellent interfacial affinity. This structure enables the catalyst to efficiently transfer peroxide anions from the aqueous phase to the oil phase at the oil-water interface, significantly increasing the phase transfer rate. This increased reaction rate allows the main reaction to complete in a very short time, effectively competing with and suppressing the hydrolysis side reaction of 2-ethylhexyl chloroformate, thereby significantly improving the utilization rate of raw materials and the yield of the final product.

[0018] 2. This invention introduces a composite solvent system composed of hydrofluoroether and isododecane. Hydrofluoroether possesses extremely low surface tension and excellent heat capacity. During the reaction, it not only synergistically disperses the reaction system into a micron-sized emulsion through high-shear stirring, significantly increasing the contact area between the two phases, but more importantly, it can rapidly absorb and disperse the instantaneous heat released during the reaction, eliminating microscopic localized hot spots. This synergy effectively prevents the induced decomposition of thermosensitive peroxide bonds, minimizing the loss of inherent reactive oxygen species during the synthesis process.

[0019] 3. This invention introduces methyl-β-cyclodextrin during the premixing stage of the base material. Utilizing its hydrophobic cavity structure, cyclodextrin can form an inclusion complex with the hydrophobic end of tert-butyl hydrogen peroxide. This molecular-level protection shields unstable peroxides in a strongly alkaline environment, effectively inhibiting the self-accelerated decomposition and ineffective consumption of tert-butyl hydrogen peroxide upon contact with the alkaline solution. This not only further improves the effective conversion rate of the raw materials but also reduces the generation of impurity gases, ensuring the safety of the reaction process and the final purity of the product.

[0020] 4. This invention uses modified hydrotalcite to replace the traditional acid-alkali-water washing process. The stearic acid-modified hydrotalcite has excellent oleophilicity and can be uniformly dispersed in the reaction oil phase. Utilizing its structural reconstruction, it can accurately and efficiently chemically adsorb residual chloride ions and acidic impurities in the system. This solid-phase adsorption separation technology completely avoids the loss of ester products due to emulsification in the traditional water washing process, thus increasing the yield. Simultaneously, it avoids the introduction of external moisture, reducing the subsequent drying load.

[0021] 5. In the raw material pretreatment stage, this invention utilizes the inclusion effect of cyclodextrin to lock the activity of tert-butyl hydrogen peroxide, providing a stable peroxide source for subsequent reactions. In the reaction stage, while ensuring high conversion rate, the hydrolysis of chloroformate and the thermal dissociation of peroxide are suppressed to the greatest extent. In the post-treatment stage, modified hydrotalcite is used to complete the removal and purification of impurities under mild conditions. The close collaboration between each process fundamentally solves the technical contradiction of sacrificing active oxygen content in pursuit of yield in traditional processes, and finally obtains the target product with both high yield and high active oxygen content. Attached Figure Description

[0022] Figure 1 The graph shows the yield and active oxygen content of the pure product in Example 1 and Comparative Examples 1-4 of this invention. Detailed Implementation

[0023] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0024] For details, please refer to [link / reference]. Figure 1 This invention provides a method for preparing tert-butylperoxy-2-ethylhexane carbonate with high reactive oxygen content, the technical solution of which is as follows:

[0025] Example 1

[0026] 100 parts of hyperbranched polyglycidyl ether and 160 parts of isopropanol were added to a four-necked flask and heated to 50°C with stirring to dissolve. 1.5 parts of potassium hydroxide were added and stirred for 30 minutes to obtain an activated solution. The activated solution was heated to 80°C, and 40 parts of 1,2-epoxydodecane were slowly added dropwise through a constant-pressure dropping funnel over a period of 1 hour. After the addition was complete, the mixture was refluxed at 80°C for 4 hours to obtain the reaction system. The reaction system was then kept at 80°C, and a mixture containing 2,3-epoxydodecane was added dropwise. - An isopropanol solution of 2,3-epoxypropyltrimethylammonium chloride (80 parts of 2,3-epoxypropyltrimethylammonium chloride dissolved in 120 parts of isopropanol) was added dropwise over 1.5 h. After the addition was complete, the temperature was raised to 80 °C and the reaction continued for 6 h. After the reaction was completed, most of the isopropanol was removed by vacuum distillation. The remaining viscous liquid was poured into 1000 parts of cold acetone to precipitate and remove unreacted small molecule monomers. The solid was collected by filtration and dried in a vacuum oven at 50 °C for 12 h to obtain the modified catalyst.

[0027] Solution A was prepared by dissolving 150 parts magnesium nitrate and 75 parts aluminum nitrate in 400 parts deionized water; solution B was prepared by dissolving 60 parts sodium hydroxide and 20 parts sodium carbonate in 400 parts deionized water; solution B was prepared by adding 5 parts sodium stearate to 105 parts deionized water, heating to 80°C and stirring until the sodium stearate was completely dissolved, forming a sodium stearate solution; under vigorous stirring, solutions A and B were simultaneously added dropwise to a reactor containing 200 parts deionized water, controlling the addition time at 1.5 hours and maintaining the pH of the system at approximately 9.5. After the addition was complete, the resulting white slurry was heated to 65°C, filtered, and then treated with deionized water. The filter cake was repeatedly washed with deionized water until the pH of the washing solution was neutral. The filter cake was then dried in an oven at 100°C for 12 hours and ground to obtain a hydrotalcite precursor. The hydrotalcite precursor was placed in a muffle furnace and heated to 450°C at a heating rate of 5°C / min, and calcined at this temperature for 4 hours to obtain calcined hydrotalcite. Five parts of sodium stearate were added to 105 parts of deionized water, the temperature was raised to 80°C and stirred until the sodium stearate was completely dissolved to form a sodium stearate solution. The calcined hydrotalcite was dispersed in 150 parts of anhydrous ethanol, the sodium stearate solution was added, and the mixture was stirred and refluxed at 70°C for 1.5 hours. After filtration and washing, the mixture was vacuum dried to obtain modified hydrotalcite.

[0028] In a reactor equipped with a cryogenic jacket and a high-shear dispersion disk (the ratio of the dispersion disk diameter to the reactor diameter is 1:3), add 60 parts of 45% potassium hydroxide solution and 0.2 parts of methyl-β-cyclodextrin, start low-speed stirring (150 rpm), lower the reactor temperature to 5°C, slowly add 68 parts of 70% tert-butyl hydrogen peroxide solution, control the dropping rate so that the internal temperature does not exceed 8°C, after the dropping is completed, keep at 6°C and stir for 15-25 minutes to obtain a premixed solution;

[0029] Add 180 parts of composite solvent and 0.6 parts of modified catalyst to the premixed solution, start high-shear stirring, increase the speed to 1300 rpm, and continue for 10 min to obtain a composite emulsion; adjust the coolant in the reactor jacket to control the temperature inside the reactor at 10℃±1℃, and add 100 parts of 2-ethylhexyl chloroformate dropwise through a precision metering pump, with the dropper tip inserted below the liquid surface (subsurface feeding), for 85 min, while maintaining the stirring speed at 9000 rpm (check the pH of the aqueous phase to ensure the final pH > 9.0). After the dropwise addition is completed, slowly raise the temperature to 20℃, and continue to maintain the temperature and stir for 30 min to obtain the reaction mixture; the composite solvent includes isododecane and hydrofluoroether, with a weight ratio of isododecane to hydrofluoroether of 4:1;

[0030] Stop stirring and allow the reaction mixture to stand for 20 minutes to separate and remove the high-salt water phase. Add 2.5 parts of modified hydrotalcite to the oil phase remaining in the reactor, start medium-speed stirring (300 rpm), and adsorb at 25°C for 20 minutes to obtain an oil phase mixture. Pump the oil phase mixture into a plate and frame filter press (with 1 μm filter cloth) to filter out the modified hydrotalcite that has adsorbed impurities, and obtain the filtrate. Pass the filtrate through an adsorption column packed with strong acid cation exchange resin (D001) to remove the modified catalyst and collect the effluent. The effluent enters a short-path molecular distillation apparatus with an evaporation surface temperature of 35°C, a system pressure of <50 Pa (high vacuum), and a scraper rotation speed of 300 rpm. The light components (isododecane, HFE-7100, tert-butanol, and trace amounts of water) are condensed and recovered from the top (can be recycled), while the heavy components (tert-butylperoxy-2-ethylhexane carbonate) are discharged from the bottom, filtered through a 0.2 μm filter element, and then bottled.

[0031] Examples 2-5 refer to the parameter conditions in Example 1, with specific differences shown in Table 1.

[0032]

[0033] Comparative Example 1 follows the same parameters and conditions as in Example 1, except that methyl-β-cyclodextrin is not added.

[0034] Comparative Example 2 follows the same parameters and conditions as in Example 1, except that 180 parts of isododecane are used instead of the composite solvent.

[0035] Comparative Example 3 follows the same parameters and conditions as in Example 1, except that the hyperbranched polyglycidyl ether is not modified.

[0036] Comparative Example 4 follows the same parameters and conditions as in Example 1, except that no modified catalyst is added.

[0037] Experimental Example 1: Conversion Rate, Yield, and Reactive Oxygen Species Content Test

[0038] The conversion rate, yield, and reactive oxygen species content (iodometric method) of Examples 1-5 and Comparative Examples 1-4 were tested, and the results are shown in Table 2. The yields of Examples 1 and Comparative Examples 1-4, as well as the reactive oxygen species content of the pure products, are shown in Table 2. Figure 1 As shown.

[0039]

[0040] From Table 2 and Figure 1It can be observed that the absence of methyl-β-cyclodextrin in Comparative Example 1 resulted in a decrease in conversion rate of approximately 3.1%, a decrease in yield of 3.6%, and a reduction in reactive oxygen species content. This is because tert-butyl hydrogen peroxide is highly susceptible to induced decomposition under strongly alkaline conditions. In Example 1, cyclodextrin effectively shielded the peroxide from direct impact by the alkaline solution through host-guest inclusion, thus protecting the activity of tert-butyl hydrogen peroxide. However, Comparative Example 1 lacked this protection, and some tert-butyl hydrogen peroxide decomposed and became ineffective before participating in the reaction, leading to a decrease in raw material utilization. Furthermore, the decomposition products remained as impurities in the system, lowering the reactive oxygen species content of the final product. Comparative Example 2, which used only isododecane without hydrofluoroether, showed a significant decline in both yield and reactive oxygen species content (yield only 90.1%, reactive oxygen species reduced to 6.01%). This fully demonstrates the dual crucial role of fluorocarbon solvents in this system: on the one hand, the lack of the low surface tension characteristic of hydrofluoroether prevents the reaction system from forming a stable micron-scale microemulsion under high shear, reducing the oil-water contact area and slowing the reaction rate, thus allowing 2-ethylhexyl chloroformate more time to undergo hydrolysis side reactions; on the other hand, the absence of the heat sink effect of hydrofluoroether means that the heat released instantaneously during the reaction cannot be quickly removed, and local overheating leads to the breakage of some heat-sensitive peroxy bonds, thereby significantly reducing the reactive oxygen species content of the product. Comparative Example 3 used unmodified hyperbranched polyglycidyl ether, and the results showed that all indicators were significantly worse than those of Example 1 (conversion rate of only 86.4%). This is because the unmodified polyether skeleton is too hydrophilic and lacks quaternary ammonium salt positive charge active centers, making it unable to form an effective ion transport channel at the oil-water interface. The catalyst could not efficiently transport peroxide anions from the aqueous phase to the oil phase to contact with the chloroformate, resulting in extremely poor reaction kinetics. The reaction was mainly limited by physical diffusion, and a large amount of raw materials underwent ineffective hydrolysis due to prolonged contact with alkaline solution. Comparative Example 4 served as a blank control. Without the use of any catalyst, the reaction conversion rate and yield were extremely low (72.1% and 65.3%, respectively), and the active oxygen content was even less than 6.0%. This indicates that the synthesis of tert-butylperoxy-2-ethylhexane carbonate is a typical interface-controlled reaction. Simply relying on stirring cannot overcome the interphase mass transfer resistance. It is necessary to rely on the highly efficient catalytic system constructed in this invention to break through the interphase interface barrier.

[0041] Examples 6-9 refer to the parameter conditions in Example 1, with specific differences shown in Table 3.

[0042]

[0043] Comparative Example 5 follows the same parameters and conditions as in Example 1, except that a hydrotalcite precursor is used instead of modified hydrotalcite.

[0044] Comparative Example 6 uses the same parameters and conditions as in Example 1, except that the modified hydrotalcite is replaced with the traditional acid-alkali-water washing method.

[0045] Comparative Example 7 follows the same parameters and conditions as in Example 1, except that the effluent is not separated by distillation, but only by centrifugation.

[0046] Experimental Example 2: Conversion Rate, Yield, and Reactive Oxygen Species Content Test

[0047] The conversion rate, yield, and reactive oxygen species content (iodometric method) of Examples 1, 6-9, and Comparative Examples 5-7 were tested, and the results are shown in Table 4.

[0048]

[0049] Table 4 shows that when Comparative Example 5 used an uncalcined hydrotalcite precursor to replace the modified hydrotalcite, the yield dropped to 94.1% and the active oxygen content dropped to 6.03%. This is because the hydrotalcite precursor has a stable structure, and the interlayer is occupied by carbonate and water molecules. It lacks the memory effect and high-energy defect sites formed after calcination. Therefore, it cannot strongly chemically adsorb chloride ions and acidic impurities in the system through the structural reconstruction mechanism like the modified hydrotalcite. The incomplete removal of impurities led to acid-catalyzed micro-degradation of the product during post-processing and drying, which not only caused a loss in yield but also reduced the purity and active oxygen content of the final product. Comparative Example 6 used a traditional "acid washing-alkali washing-water washing" process. Although the active oxygen content was acceptable (6.07%), the yield dropped drastically to only 88.6%. The reason for this significant difference is that the tert-butylperoxy-2-ethylhexane carbonate system contains surface-active components, which easily form a stable emulsion when stirred with a large amount of water. The traditional water washing process cannot completely separate oil and water, resulting in a large amount of ester products being encapsulated in the emulsion layer and discharged with the wastewater, causing serious physical loss. In contrast, the anhydrous solid-phase adsorption process used in Example 1 completely avoids the introduction of the aqueous phase, fundamentally eliminating emulsification, thus achieving a very high process yield while ensuring high purity. Comparative Example 7 only used centrifugation to remove solids in the post-treatment without short-path molecular distillation, resulting in a significant reduction in its active oxygen content to 4.48%. This is because the reaction system not only contained the target product but also residual reaction solvents (isododecane, hydrofluoroether) and the reaction byproduct tert-butanol. Centrifugation can only remove the solid hydrotalcite adsorbent, but cannot remove the liquid light component impurities mentioned above. These inactive substances remain in the final product, which has a dilutive effect and seriously lowers the product's reactive oxygen species index. In Example 1, by using short-path molecular distillation, the differences in boiling points and molecular free paths of different components were utilized to physically remove all light components under low temperature and high vacuum, ensuring the purity of the final product.

[0050] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A method for preparing tert-butylperoxy-2-ethylhexane carbonate with high reactive oxygen content, characterized in that, Includes the following steps: A premixed solution was obtained by mixing potassium hydroxide solution, methyl-β-cyclodextrin, and tert-butyl hydrogen peroxide solution. A composite solvent, a modified catalyst, and 2-ethylhexyl chloroformate were added to the premixed solution, and a reaction mixture was obtained after reaction. The reaction mixture was post-treated with modified hydrotalcite to obtain tert-butyl peroxide-2-ethylhexyl carbonate. The composite solvent was obtained by mixing isododecane and hydrofluoroether. The modified catalyst was prepared by hyperbranched polyglycidyl ether, 1,2-epoxydodecane, potassium hydroxide, and 2,3-epoxypropyltrimethylammonium chloride.

2. The method for preparing tert-butylperoxy-2-ethylhexane carbonate with high reactive oxygen content according to claim 1, characterized in that, The premixed solution is prepared by adding the potassium hydroxide solution and the methyl-β-cyclodextrin to a reaction vessel, and adding the tert-butyl hydrogen peroxide solution dropwise while stirring. After the addition is complete, stirring is continued to obtain the premixed solution.

3. The method for preparing tert-butylperoxy-2-ethylhexane carbonate with high reactive oxygen content according to claim 1, characterized in that, The reaction mixture is prepared by adding the composite solvent and the modified catalyst to the premixed solution and stirring continuously to obtain a composite emulsion; adding 2-ethylhexyl chloroformate dropwise to the composite emulsion, and stirring and maturing after the addition is complete to obtain the reaction mixture.

4. The method for preparing tert-butylperoxy-2-ethylhexane carbonate with high reactive oxygen content according to claim 1, characterized in that, The weight ratio of isododecane to hydrofluoroether is 3-5:

1.

5. The method for preparing tert-butylperoxy-2-ethylhexane carbonate with high reactive oxygen content according to claim 1, characterized in that, The modified catalyst is prepared as follows: Hyperbranched polyglycidyl ether and isopropanol are added to a four-necked flask, stirred to dissolve, and then potassium hydroxide is added and stirred to obtain an activation solution; 1,2-epoxydodecane is added dropwise to the activation solution, and after the addition is complete, the mixture is refluxed to obtain a reaction system; an isopropanol solution containing 2,3-epoxypropyltrimethylammonium chloride is added dropwise to the reaction system, and after the addition is complete, the reaction continues. After the reaction is complete, the mixture is distilled under reduced pressure, the precipitate is collected by filtration, and the solid is dried under vacuum to obtain the modified catalyst.

6. The method for preparing tert-butylperoxy-2-ethylhexane carbonate with high reactive oxygen content according to claim 1, characterized in that, The specific process of post-treatment of the modified hydrotalcite is as follows: the reaction mixture is allowed to stand and separate into layers, the aqueous phase is removed, the modified hydrotalcite is added to the oil phase in the reactor, and the mixture is stirred and adsorbed to obtain an oil phase mixture; the oil phase mixture is filtered to remove adsorption and obtain a filtrate; the filtrate is passed through an adsorption column to remove the modified catalyst and the effluent is collected; the effluent is distilled, the components at the bottom are collected and filtered, which is the tert-butylperoxy-2-ethylhexane carbonate.

7. The method for preparing tert-butylperoxy-2-ethylhexane carbonate with high reactive oxygen content according to claim 6, characterized in that, The modified hydrotalcite is prepared as follows: the hydrotalcite precursor is placed in a muffle furnace and calcined at 440-460℃ for 3-5 hours to obtain calcined hydrotalcite; sodium stearate is added to deionized water and stirred to form a sodium stearate solution; the calcined hydrotalcite is dispersed in anhydrous ethanol, the sodium stearate solution is added, the mixture is stirred and refluxed, filtered and washed, and then vacuum dried to obtain the modified hydrotalcite.

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