MOF-confined heteropolyacid-ionic liquid gel catalyst, its preparation method, and method for preparing organic peroxides

Abstract

The application belongs to the technical field of carbon ring compounds, and particularly relates to a MOF confined heteropoly acid-ion liquid gel catalyst, a preparation method thereof and a method for preparing organic peroxide. The structure of the MOF confined heteropoly acid-ion liquid gel catalyst is that a MOF confined heteropoly acid is taken as a core, and a pH responsive ion liquid gel is coated outside the core; wherein the MOF is UiO-66-SO3H, the heteropoly acid is phosphotungstic acid, and the pH responsive ion liquid gel is a 1-butyl-3-methyl imidazole chloride and polyacrylic acid composite. The application has many advantages such as strong oxidizing property, strong acidity, high stability, easy recycling and cyclic use, reduction of equipment corrosion and reduction of waste acid treatment problems, and can reduce the use of sulfuric acid and the discharge of waste acid.

Description

Technical Field

[0001] This invention belongs to the field of carbocyclic compound technology, specifically relating to a MOF-confined heteropolyacid-ionic liquid gel catalyst, its preparation method, and a method for preparing organic peroxides. Background Technology

[0002] 1,1-Bis(tert-butylperoxy)-3,3,5-trimethylcyclohexane is an important organic peroxide with wide applications in polymerization initiation and cross-linking curing of polymer materials. Currently, the most common method for the industrial production of 1,1-bis(tert-butylperoxy)-3,3,5-trimethylcyclohexane is to react tert-butyl hydroperoxide with 3,3,5-trimethylcyclohexanone under acidic conditions, followed by liquid-liquid separation of the crude 1,1-bis(tert-butylperoxy)-3,3,5-trimethylcyclohexane through alkaline washing, water washing, and drying to obtain the finished product, 1,1-bis(tert-butylperoxy)-3,3,5-trimethylcyclohexane.

[0003] Chinese patent CN102336694A discloses a method for synthesizing bis(tert-butylperoxy)ketal. This patent uses one of the following as raw materials, R1 (selected from cyclohexanone, 3,3,5-trimethylcyclohexanone, or butyl levulinate) and tert-butyl hydroperoxide R2. The reaction is carried out in the presence of a catalyst at atmospheric pressure, at a reaction temperature of -20 to 40°C, with a molar ratio of R2 to R1 of 2 to 10:1 and a catalyst to R1 weight ratio of 0.01 to 0.50:1, for 0.5 to 10 hours to obtain the corresponding products 1,1-bis(tert-butylperoxy)cyclohexane, 1,1-bis(tert-butylperoxy)-3,3,5-trimethylcyclohexane, or 4,4-bis(tert-butylperoxy)valerate. The catalyst is a mixture of H2SO4 and an acid M other than H2SO4, with a weight ratio of H2SO4:M = 0.5 to 15:1. Patent 102336695A discloses a method for producing bis(tert-butylperoxy)ketal. This patent uses one of the following as raw materials: R1 (selected from cyclohexanone, 3,3,5-trimethylcyclohexanone, or butyl acetalate) and tert-butyl hydroperoxide R2. The reaction is carried out in the presence of a solvent, under normal pressure, at a reaction temperature of -20 to 40°C, with a molar ratio of R2 to R1 of 2 to 10:1, a catalyst weight ratio of 0.01 to 0.50:1, and the amount of solvent being 20 to 80% of the total weight of reactants R1 and R2. The reaction is carried out for 0.5 to 10 hours to obtain the corresponding products: 1,1-bis(tert-butylperoxy)cyclohexane, 1,1-bis(tert-butylperoxy)-3,3,5-trimethylcyclohexane, or 4,4-bis(tert-butylperoxy)valerate. The catalyst is selected from at least one of sulfuric acid, phosphoric acid, hydrochloric acid, perchloric acid, p-toluenesulfonic acid, nitric acid, or acetic acid. The two patents mentioned above use a large amount of sulfuric acid in the production process, which cannot be recycled and is ultimately discharged as waste liquid, and the waste liquid is difficult to treat.

[0004] Chinese patent CN114014791A discloses a method for preparing 1,1-bis(tert-butylperoxy)cyclohexane. This patent involves mixing tert-butyl hydroperoxide, a desensitizing agent, a solid acid, and a phase transfer catalyst, then adding cyclohexanone. In the presence of the solid acid, cyclohexanone reacts with tert-butyl hydroperoxide to generate 1,1-bis(tert-butylperoxy)cyclohexane. The mixture is then filtered, and the filtrate is separated, followed by alkali washing, water washing, and drying. After drying, the final product, 1,1-bis(tert-butylperoxy)cyclohexane, is obtained. Chinese patent CN113880743A discloses a method for preparing 1... A method for preparing 1,1-bis(tert-butylperoxy)-3,3,5-trimethylcyclohexane is described in this patent. The method involves mixing tert-butyl hydrogen peroxide, a desensitizing agent, a solid acid, and a phase transfer catalyst. Then, 3,3,5-trimethylcyclohexanone is added. In the presence of the solid acid, 3,3,5-trimethylcyclohexanone reacts with tert-butyl hydrogen peroxide to generate 1,1-bis(tert-butylperoxy)-3,3,5-trimethylcyclohexane. The mixture is then filtered, and the filtrate is separated and subsequently subjected to alkali washing, water washing, and drying. After drying, the final product, 1,1-bis(tert-butylperoxy)-3,3,5-trimethylcyclohexane, is obtained. Both of the above patents utilize a strong acid cation exchange resin and SO42-. 2- / ZrO2, acidic molecular sieves, and La prepared by sol-gel and impregnation methods 3+ One or more of / CNMS-SO3H are used as solid acid catalysts to catalyze the synthesis of the target product. The solid acid is easy to recover and can be reused, reducing acid-containing wastewater and making the wastewater easier to treat. However, the influence of factors such as acid strength, acid agglomeration, acid dissolution and acid dispersibility in heterogeneous systems on the chemical reaction is not comprehensively considered, resulting in low product purity and yield.

[0005] Chinese patent CN102850249A discloses a method for preparing 1,1-bis(tert-butylperoxy)-3,3,5-trimethylcyclohexane. This patent involves adding tert-butyl hydroperoxide and 3,3,5-trimethylcyclohexanone to a mixing vessel and stirring to separate the lower aqueous phase; adding sulfuric acid and recycled mother liquor to an acid mixing vessel and stirring; adding the mixture of tert-butyl hydroperoxide and 3,3,5-trimethylcyclohexanone, along with a catalytic sulfuric acid solution, to a synthesis vessel and stirring; introducing the reaction product into a separation tank for separation; mixing the lower aqueous phase containing sulfuric acid mother liquor with sulfuric acid; and introducing the upper crude 1,1-bis(tert-butylperoxy)-3,3,5-trimethylcyclohexane into a post-treatment vessel; and sequentially subjecting the crude 1,1-bis(tert-butylperoxy)-3,3,5-trimethylcyclohexane in the post-treatment vessel to alkali washing, water washing, drying, and filtration to obtain the final product. This patent involves mixing the sulfuric acid-containing mother liquor in the lower aqueous phase after the reaction with a certain amount of concentrated sulfuric acid (98% by mass) to continue participating in the reaction. This reduces waste liquid discharge, thus protecting the environment, and saves raw materials, thus reducing preparation costs. However, it cannot completely avoid waste acid discharge and still has problems such as low acid circulation times, local overheating caused by dripping acid, and equipment corrosion. Summary of the Invention

[0006] The purpose of this invention is to provide a MOF-confined heteropolyacid-ionic liquid gel catalyst, which has many advantages such as strong oxidizing power, strong acidity, high stability, easy recovery and recycling, reduced equipment corrosion and reduced waste acid treatment problems, and can reduce the use of sulfuric acid and the discharge of waste acid. This invention also provides a method for preparing the MOF-confined heteropolyacid-ionic liquid gel catalyst and a method for preparing organic peroxides.

[0007] The MOF-confined heteropolyacid-ionic liquid gel catalyst of the present invention has a structure in which a heteropolyacid confined in a MOF is used as the core and a pH-responsive ionic liquid gel is coated on the outside of the core; wherein, the MOF is UiO-66-SO3H, the heteropolyacid is phosphotungstic acid, and the pH-responsive ionic liquid gel is a complex of 1-butyl-3-methylimidazolium chloride and polyacrylic acid.

[0008] The preparation method of the MOF-confined heteropolyacid-ionic liquid gel catalyst of the present invention includes the following steps:

[0009] (1) MOF was immersed in phosphotungstic acid ethanol solution and stirred, filtered, and vacuum dried and solidified to obtain MOF particles loaded with phosphotungstic acid;

[0010] (2) MOF particles loaded with phosphotungstic acid were dispersed in a mixed solution under nitrogen conditions, and a photoinitiator was added for UV polymerization. The MOF confined heteropolyacid-ionic liquid gel catalyst was obtained by vacuum drying.

[0011] In step (1), the MOF is prepared by adding UiO-66-NH2 and 1,3-propanesulfonyl lactone to N,N-dimethylformamide, reacting at 60-80℃ for 12-24 h, filtering, and drying to obtain MOF. The mass ratio of UiO-66-NH2 to 1,3-propanesulfonyl lactone is 1:1-1.2, and the ratio of UiO-66-NH2 to N,N-dimethylformamide is 1:15-20. -NH2 is expressed in g, N,N-dimethylformamide in mL; the concentration of phosphotungstic acid ethanol solution is 0.1~0.2mol / L; the ratio of MOF to phosphotungstic acid ethanol solution is 6:150~200, MOF is expressed in g, phosphotungstic acid ethanol solution in mL; the stirring time is 12~24h, the vacuum degree of vacuum drying and curing is 100~1000Pa, the vacuum drying and curing temperature is 60~80℃, and the vacuum drying and curing time is 10~12h.

[0012] In step (2), the mixed solution is a mixture of 1-butyl-3-methylimidazole chloride and acrylic acid, with a mass ratio of 1-butyl-3-methylimidazole chloride to acrylic acid of 1:1~4; the mass of MOF particles loaded with phosphotungstic acid is 10~20% of the mass of the mixed solution; the photoinitiator is 2,4-diethylthioxanthone, with an amount of photoinitiator of 1~3% of the mass of acrylic acid; the UV wavelength for UV polymerization is 365~385nm, preferably 385nm, and the UV polymerization time is 30~60min, preferably 40min; the vacuum drying temperature is 50~70℃, and the vacuum drying time is 11~13h.

[0013] The method for preparing organic peroxides based on the MOF-confined heteropolyacid-ionic liquid gel catalyst of the present invention includes the following steps:

[0014] (a) MOF-confined heteropolyacid-ionic liquid gel catalyst was added to an aqueous tert-butanol solution, followed by an aqueous hydrogen peroxide solution, and the reaction yielded an aqueous tert-butyl hydrogen peroxide solution containing the MOF-confined heteropolyacid-ionic liquid gel catalyst.

[0015] (b) 3,3,5-trimethylcyclohexanone and a desensitizer were added to the tert-butyl hydrogen peroxide aqueous solution containing the MOF-confined heteropolyacid-ionic liquid gel catalyst obtained in step (a) for reaction. The reaction was carried out by filtration to obtain the MOF-confined heteropolyacid-ionic liquid gel catalyst and the reaction solution. The MOF-confined heteropolyacid-ionic liquid gel catalyst was recycled. The reaction solution was allowed to stand and separate into layers to remove the lower aqueous phase to obtain crude 1,1-bis(tert-butylperoxy)-3,3,5-trimethylcyclohexane. The crude 1,1-bis(tert-butylperoxy)-3,3,5-trimethylcyclohexane was subjected to alkali washing, water washing, drying and filtration in sequence to obtain 1,1-bis(tert-butylperoxy)-3,3,5-trimethylcyclohexane.

[0016] In step (a), the concentration of the tert-butanol aqueous solution is 70-85 wt%, and the concentration of the hydrogen peroxide aqueous solution is 40-60 wt%; the molar ratio of hydrogen peroxide in the hydrogen peroxide aqueous solution to tert-butanol in the tert-butanol aqueous solution is 1.05-1.30:1; the reaction temperature is 50-70℃, preferably 55-70℃, and the reaction time is 3-6 h, preferably 3-4 h.

[0017] In step (a), the MOF-confined heteropolyacid-ionic liquid gel catalyst is added at a time of 5-10 min, and the mass ratio of the MOF-confined heteropolyacid-ionic liquid gel catalyst to the tert-butanol aqueous solution is 0.2-0.3:1.

[0018] In step (b), the desensitizer is one of n-alkanes, isoalkanes, ethylbenzene, or liquid paraffin; the mass ratio of the desensitizer to 3,3,5-trimethylcyclohexanone is 0.09~0.10:1; the reaction temperature is room temperature, and the reaction time is 3~5h.

[0019] The molar ratio of tert-butanol to 3,3,5-trimethylcyclohexanone in the aqueous solution of tert-butanol is 2.1~2.4:1.

[0020] In step (b), the alkaline washing involves adding a 5-6 wt% sodium hydroxide solution to the crude 1,1-bis(tert-butylperoxy)-3,3,5-trimethylcyclohexane product, stirring for 15-30 min, and allowing it to stand to separate into layers to obtain the organic phase; the water washing involves adding deionized water to the organic phase obtained after alkaline washing, stirring for 15-30 min, and allowing it to stand to separate into layers to obtain the organic phase; and the drying process involves drying with anhydrous magnesium sulfate.

[0021] The chemical reaction equation of this invention is as follows:

[0022]

[0023] This invention disperses the prepared MOF-confined heteropolyacid-ionic liquid gel catalyst in a tert-butanol aqueous solution, then adds an aqueous hydrogen peroxide solution, and heats the solution for oxidation to obtain an aqueous solution of tert-butyl hydrogen peroxide containing the MOF-confined heteropolyacid-ionic liquid gel catalyst. 3,3,5-trimethylcyclohexanone and a desensitizing agent are added to the tert-butyl hydrogen peroxide aqueous solution containing the MOF-confined heteropolyacid-ionic liquid gel catalyst. Under the catalytic action of the MOF-confined heteropolyacid-ionic liquid gel catalyst, 3,3,5-trimethylcyclohexanone and a desensitizing agent are added. - Trimethylcyclohexanone reacts with tert-butyl hydroperoxide, and the reaction is filtered to obtain a MOF-confined heteropolyacid-ionic liquid gel catalyst and a reaction solution. The reaction solution is allowed to stand and separate into layers to remove the lower aqueous phase, yielding a crude product of 1,1-bis(tert-butylperoxy)-3,3,5-trimethylcyclohexane. The crude product of 1,1-bis(tert-butylperoxy)-3,3,5-trimethylcyclohexane is then subjected to alkali washing, water washing, drying, and filtration to obtain 1,1-bis(tert-butylperoxy)-3,3,5-trimethylcyclohexane. The MOF-confined heteropolyacid-ionic liquid gel catalyst of this invention uses zirconium-based MOF (UiO-66-SO3H) to confine phosphotungstic acid (H3PW). 12 O 40 With a core of 1,1-bis(tert-butylperoxy)-3,3,5-trimethylcyclohexane, coated with a pH-responsive ionic liquid gel (a complex of 1-butyl-3-methylimidazolium chloride and polyacrylic acid), it has many advantages such as strong oxidizing properties, strong acidity, high stability, easy recycling and reuse, reduced equipment corrosion and waste acid treatment problems. It can be recycled more than 30 times, and the final product, 1,1-bis(tert-butylperoxy)-3,3,5-trimethylcyclohexane, is a colorless and transparent solution that meets 90% of the standard product requirements and can be used for industrial production.

[0024] The beneficial effects of this invention are as follows:

[0025] 1. In this invention, the tert-butyl hydrogen peroxide aqueous solution containing MOF-confined heteropolyacid-ionic liquid gel catalyst obtained after the reaction of the first step of tert-butanol aqueous solution and hydrogen peroxide aqueous solution does not require further treatment. It can be directly added to 3,3,5-trimethylcyclohexanone for reaction, saving time and cost. At the same time, due to the principle of polarity and like dissolves like, part of the tert-butyl hydrogen peroxide product dissolved in the aqueous phase is extracted into the 3,3,5-trimethylcyclohexanone organic phase, reducing the waste of tert-butyl hydrogen peroxide and improving the yield of the next step reaction. Finally, a colorless and transparent 1,1-bis(tert-butylperoxy)-3,3,5-trimethylcyclohexane that meets the 90% specification standard product requirements is obtained.

[0026] 2. The MOF-confined heteropolyacid-ionic liquid gel catalyst used in this invention combines the acidic synergistic effect and confinement effect of metal-organic frameworks (MOFs), the high catalytic activity of heteropolyacids (HPAs), and the stabilizing effect and dynamic response of ionic liquid gels. It has significant breakthroughs in catalytic efficiency, stability, and recyclability, with the following core advantages:

[0027] (1) HPA is extremely acidic and has excellent catalytic performance. It has high solubility in water and exhibits strong polar solvent-induced loss characteristics. Through the physical confinement effect of MOF channels, HPA is loaded in mesoporous / macroporous defects, and its movement is spatially constrained, avoiding severe aggregation and achieving a high degree of dispersion. In addition, there is a strong electrostatic and hydrogen bond interaction between HPA and the sulfonic acid groups of UiO-66-SO3H. This chemical action can also fix and disperse HPA, playing a similar role to "chemical confinement". After the solidified ionic liquid gel, a large number of hydrogen bonds form a strong "adhesive network" between the MOF surface, polymer chains and ionic liquid, making them firmly bonded together. This not only prevents the loss of heteropolyacids, but also helps MOF particles to be stably dispersed in the gel system for a long time, preventing their aggregation and sedimentation.

[0028] (2) The sulfonic acid group (-SO3H), the carboxyl group (-COOH) on the polyacrylic acid chain and the heteropoly acid (HPA) of the functionalized MOF are activated in series to activate the substrate. Through the spatial organization and functional synergy of multiple acidic sites, a catalytic effect of 1+1+1>3 is achieved.

[0029] (3) In the MOF-confined heteropolyacid-ionic liquid gel catalyst, the MOF particles (HPA@UiO-66-SO3H particles) loaded with phosphotungstic acid are uniformly embedded in the entire ionic liquid gel of 1-butyl-3-methylimidazolium chloride and polyacrylic acid composite. At this time, the gel (neutral state) is swollen and the polymer chains are extended, which "deeply hides" the MOF particles loaded with phosphotungstic acid inside the grid, protecting the MOF particles loaded with phosphotungstic acid from wear. When the MOF-confined heteropolyacid-ionic liquid gel catalyst is put into the reaction environment of hydrogen peroxide / tert-butyl hydrogen peroxide, since the reaction system is acidic, a large amount of H + Make the carboxyl groups (-COO) on the polyacrylic acid chain -The polymer rapidly protonates, transforming into electrically neutral -COOH. After protonation, hydrogen bonding and hydrophobic interactions between polyacrylic acid chains become dominant, causing the entire polymer network to shrink dramatically. This shrinkage process produces an "extrusion" effect, pushing more HPA@UiO-66-SO3H particles, which were originally wrapped and shielded by the long polymer chains, to the surface and pores of the gel material, exposing more active sites and participating in the reaction. After the reaction, the solution pH increases, and the neutral environment triggers gel swelling, which again covers and protects the HPA@UiO-66-SO3H particles.

[0030] (4) The MOF support makes the catalyst easy to separate by filtration or centrifugation, avoiding the problem of recycling homogeneous catalysts (such as H2SO4). The catalyst can be recycled more than 30 times, while reducing equipment corrosion and waste acid treatment problems, which is in line with the concept of green chemistry and sustainability.

[0031] In summary, HPA provides highly active acid sites, dominating the catalytic reaction; MOF provides structural support and confinement effects, immobilizing heteropolyacids to create heterogeneous catalysts that are easy to recover; ionic liquid gels have a dual function: first, as a host to immobilize catalyst particles, preventing their deactivation and loss, and improving stability; second, as a smart regulating medium, its network structure can dynamically and reversibly swell / contract with the ambient pH, thereby regulating reactant contact and catalyst diffusion, and after the reaction, it achieves in-situ protection of the catalyst through swelling, fundamentally improving the catalyst's cycle durability; the three work synergistically to achieve a "1+1+1>3" effect, suitable for harsh reaction conditions (such as strong acids and oxidizing environments), providing a new paradigm for heterogeneous catalyst design.

[0032] 3. The MOF support in the catalyst of this invention can enhance heat transfer and prevent local overheating that could lead to aggravated side reactions or peroxide explosions. Simultaneously, it avoids the problems of violent system reactions and excessively high local temperatures caused by concentrated sulfuric acid dripping in traditional processes, which can lead to raw material carbonization and changes in product color, affecting product quality and yield. Furthermore, traditional processes typically require lowering the system temperature and dripping rate to reduce side reactions, while this invention can further shorten reaction time, reduce costs, and increase product yield. This invention operates at room temperature, requiring no additional heating or cooling methods, which is energy-efficient, and the reaction is faster and has a higher conversion rate at room temperature. Attached Figure Description

[0033] Figure 1 The liquid chromatogram of 1,1-bis(tert-butylperoxy)-3,3,5-trimethylcyclohexane in Example 1 is shown.

[0034] Figure 2The image shows the 1H NMR spectrum of 1,1-bis(tert-butylperoxy)-3,3,5-trimethylcyclohexane from Example 1.

[0035] Figure 3 The liquid chromatogram of 1,1-bis(tert-butylperoxy)-3,3,5-trimethylcyclohexane in Example 2 is shown.

[0036] Figure 4 The 1H NMR spectrum of 1,1-bis(tert-butylperoxy)-3,3,5-trimethylcyclohexane in Example 2 is shown.

[0037] Figure 5 The liquid chromatogram of 1,1-bis(tert-butylperoxy)-3,3,5-trimethylcyclohexane in Example 3 is shown.

[0038] Figure 6 The image shows the 1H NMR spectrum of 1,1-bis(tert-butylperoxy)-3,3,5-trimethylcyclohexane in Example 3.

[0039] Figure 7 The liquid chromatogram of 1,1-bis(tert-butylperoxy)-3,3,5-trimethylcyclohexane in Comparative Example 1 is shown.

[0040] Figure 8 The liquid chromatogram of 1,1-bis(tert-butylperoxy)-3,3,5-trimethylcyclohexane in Comparative Example 2 is shown.

[0041] Figure 9 The liquid chromatogram of 1,1-bis(tert-butylperoxy)-3,3,5-trimethylcyclohexane in Comparative Example 3 is shown. Detailed Implementation

[0042] The present invention will be further described below with reference to embodiments.

[0043] Example 1

[0044] (1) 10g UiO-66-NH2 and 10g 1,3-propanesulfonyl lactone were added to 150mL N,N-dimethylformamide and reacted at 80℃ for 12h. After filtration and drying, UiO-66-SO3H was obtained. 6g UiO-66-SO3H was immersed in 150mL of 0.2mol / L phosphotungstic acid ethanol solution and stirred for 12h. After filtration, the solution was vacuum dried and cured at 80℃ and 100Pa for 10h to obtain MOF particles loaded with phosphotungstic acid. 6g of MOF particles loaded with phosphotungstic acid were dispersed in 30g of nitrogen gas. 2,4-Diethylthioxanthrone was added to a mixed solution of 1-butyl-3-methylimidazolium chloride and acrylic acid (the mass ratio of 1-butyl-3-methylimidazolium chloride to acrylic acid was 1:1). The amount of 2,4-diethylthioxanthrone was 2% of the mass of acrylic acid. The mixture was subjected to UV polymerization under 385 nm ultraviolet light for 40 min and then vacuum dried at 60 °C for 12 h to obtain a MOF confined heteropolyacid-ionic liquid gel catalyst.

[0045] (2) In a 500 mL three-necked flask, 104.48 g of 85 wt% tert-butanol aqueous solution was added, and 25 g of MOF-confined heteropolyacid-ionic liquid gel catalyst was added at room temperature for 8 min. Then, 97.92 g of 50 wt% hydrogen peroxide aqueous solution was added, and the reaction was carried out at 60 °C for 4 h to obtain tert-butyl hydrogen peroxide aqueous solution containing MOF-confined heteropolyacid-ionic liquid gel catalyst.

[0046] (3) 70.70 g of 3,3,5-trimethylcyclohexanone with a purity of 99% and 7 g of ethylbenzene were added to the tert-butyl hydrogen peroxide aqueous solution containing MOF-confined heteropolyacid-ionic liquid gel catalyst obtained in step (2). The reaction was carried out at room temperature for 4 h. The MOF-confined heteropolyacid-ionic liquid gel catalyst and the reaction solution were obtained by filtration. The MOF-confined heteropolyacid-ionic liquid gel catalyst was recycled. The reaction solution was poured into a separatory funnel and allowed to stand for separation to remove the lower aqueous phase, thus obtaining 1,1-bis(tert-butyl) The crude product of 1,1-bis(tert-butylperoxy)-3,3,5-trimethylcyclohexane was subjected to alkaline washing by adding a 5 wt% sodium hydroxide solution to the crude product and stirring for 30 min. After standing and separating the layers, the organic phase was collected. Deionized water was added to the organic phase and stirred for 30 min for water washing. After standing and separating the layers, the organic phase was collected and dried with anhydrous magnesium sulfate. After filtration, 1,1-bis(tert-butylperoxy)-3,3,5-trimethylcyclohexane was obtained.

[0047] The purity of 1,1-bis(tert-butylperoxy)-3,3,5-trimethylcyclohexane was 90.58%, and the yield was 92.63%. The liquid chromatography results of 1,1-bis(tert-butylperoxy)-3,3,5-trimethylcyclohexane are shown below. Figure 1 See Table 1, and the proton NMR spectrum. Figure 2 .

[0048] Table 1. Liquid chromatography data results of Example 1

[0049]

[0050] Example 2

[0051] (1) 10g UiO-66-NH2 and 12g 1,3-propanesulfonyl lactone were added to 200mL N,N-dimethylformamide and reacted at 60℃ for 24h. After filtration and drying, UiO-66-SO3H was obtained. 6g UiO-66-SO3H was immersed in 190mL of 0.1mol / L phosphotungstic acid ethanol solution and stirred for 18h. After filtration, the solution was vacuum dried and cured at 60℃ and 1000Pa for 12h to obtain MOF particles loaded with phosphotungstic acid. 6g of MOF particles loaded with phosphotungstic acid were dispersed in 40g of nitrogen gas. 2,4-Diethylthioxanthrone was added to a mixed solution of 1-butyl-3-methylimidazolium chloride and acrylic acid (the mass ratio of 1-butyl-3-methylimidazolium chloride to acrylic acid was 1:2). The amount of 2,4-diethylthioxanthrone was 3% of the mass of acrylic acid. The mixture was subjected to UV polymerization under 365 nm ultraviolet light for 60 min and then vacuum dried at 50 °C for 13 h to obtain a MOF confined heteropolyacid-ionic liquid gel catalyst.

[0052] (2) In a 500 mL three-necked flask, 114.28 g of 70 wt% tert-butanol aqueous solution was added, and 28 g of MOF-confined heteropolyacid-ionic liquid gel catalyst was added at room temperature for 5 min. Then, 119.04 g of 40 wt% hydrogen peroxide aqueous solution was added, and the reaction was carried out at 50 °C for 6 h to obtain tert-butyl hydrogen peroxide aqueous solution containing MOF-confined heteropolyacid-ionic liquid gel catalyst.

[0053] (3) 72.25 g of 3,3,5-trimethylcyclohexanone with a purity of 99% and 7 g of liquid paraffin were added to the tert-butyl hydrogen peroxide aqueous solution containing the MOF-confined heteropolyacid-ionic liquid gel catalyst obtained in step (2). The reaction was carried out at room temperature for 3 h. The MOF-confined heteropolyacid-ionic liquid gel catalyst and the reaction solution were obtained by filtration. The MOF-confined heteropolyacid-ionic liquid gel catalyst was recycled. The reaction solution was poured into a separatory funnel and allowed to stand for separation to remove the lower aqueous phase, thus obtaining 1,1-bis(tert-butyl) The crude product of 1,1-bis(tert-butylperoxy)-3,3,5-trimethylcyclohexane was subjected to alkaline washing by adding a 6 wt% sodium hydroxide solution and stirring for 15 min. After standing and separating the layers, the organic phase was collected. Deionized water was added to the organic phase and stirred for 15 min for water washing. After standing and separating the layers, the organic phase was collected and dried with anhydrous magnesium sulfate. After filtration, 1,1-bis(tert-butylperoxy)-3,3,5-trimethylcyclohexane was obtained.

[0054] The purity of 1,1-bis(tert-butylperoxy)-3,3,5-trimethylcyclohexane was 90.41%, and the yield was 92.95%. The liquid chromatography results of 1,1-bis(tert-butylperoxy)-3,3,5-trimethylcyclohexane are shown below. Figure 3 See Table 2, and the proton NMR spectrum. Figure 4 .

[0055] Table 2. Liquid chromatography data results of Example 2

[0056]

[0057] Example 3

[0058] (1) 10g UiO-66-NH2 and 11g 1,3-propanesulfonyl lactone were added to 170mL N,N-dimethylformamide and reacted at 70℃ for 20h. After filtration and drying, UiO-66-SO3H was obtained. 6g UiO-66-SO3H was immersed in 200mL of 0.15mol / L phosphotungstic acid ethanol solution and stirred for 24h. After filtration, the solution was vacuum dried and cured at 70℃ and 500Pa for 11h to obtain MOF particles loaded with phosphotungstic acid. 6g of MOF particles loaded with phosphotungstic acid were dispersed in 60g of nitrogen gas. 2,4-Diethylthioxanthrone was added to a mixed solution of 1-butyl-3-methylimidazolium chloride and acrylic acid (the mass ratio of 1-butyl-3-methylimidazolium chloride to acrylic acid was 1:4). The amount of 2,4-diethylthioxanthrone was 1% of the mass of acrylic acid. The mixture was subjected to UV polymerization under 370 nm ultraviolet light for 30 min and then vacuum dried at 70 °C for 11 h to obtain a MOF confined heteropolyacid-ionic liquid gel catalyst.

[0059] (2) In a 500 mL three-necked flask, 112.50 g of 80 wt% tert-butanol aqueous solution was added, and 30 g of MOF-confined heteropolyacid-ionic liquid gel catalyst was added at room temperature for 10 min. Then, 72.60 g of 60 wt% hydrogen peroxide aqueous solution was added, and the reaction was carried out at 70 °C for 3 h to obtain tert-butyl hydrogen peroxide aqueous solution containing MOF-confined heteropolyacid-ionic liquid gel catalyst.

[0060] (3) 73.53 g of 99% pure 3,3,5-trimethylcyclohexanone and 7 g of ethylbenzene were added to the tert-butyl hydrogen peroxide aqueous solution containing the MOF-confined heteropolyacid-ionic liquid gel catalyst obtained in step (2). The reaction was carried out at room temperature for 5 h. The MOF-confined heteropolyacid-ionic liquid gel catalyst and the reaction solution were obtained by filtration. The MOF-confined heteropolyacid-ionic liquid gel catalyst was recycled. The reaction solution was poured into a separatory funnel and allowed to stand for separation to remove the lower aqueous phase, thus obtaining 1,1-bis(tert-butylhydrogen peroxide). The crude product of 1,1-bis(tert-butylperoxy)-3,3,5-trimethylcyclohexane was subjected to alkaline washing by adding a 5.5 wt% sodium hydroxide solution to the crude product and stirring for 20 min. After standing and separating the layers, the organic phase was collected. Deionized water was added to the organic phase and stirred for 20 min for water washing. After standing and separating the layers, the organic phase was collected and dried with anhydrous magnesium sulfate. After filtration, 1,1-bis(tert-butylperoxy)-3,3,5-trimethylcyclohexane was obtained.

[0061] The purity of 1,1-bis(tert-butylperoxy)-3,3,5-trimethylcyclohexane was 91.46%, and the yield was 93.58%. The liquid chromatography results of 1,1-bis(tert-butylperoxy)-3,3,5-trimethylcyclohexane are shown below. Figure 5 See Table 3, and the proton NMR spectrum. Figure 6 .

[0062] Table 3. Liquid chromatography data results of Example 3

[0063]

[0064] Comparative Example 1

[0065] Without adding phosphotungstic acid ethanol solution, the other steps are the same as in Example 3.

[0066] The purity of 1,1-bis(tert-butylperoxy)-3,3,5-trimethylcyclohexane was 32.96%, and the yield was 37.27%. The liquid chromatography results of 1,1-bis(tert-butylperoxy)-3,3,5-trimethylcyclohexane are shown below. Figure 7 And Table 4.

[0067] Table 4. Liquid chromatography data results for Comparative Example 1

[0068]

[0069] Comparative Example 2

[0070] (1) 60g of a mixed solution of 1-butyl-3-methylimidazolium chloride and acrylic acid (the mass ratio of 1-butyl-3-methylimidazolium chloride to acrylic acid is 1:4) was added to 2,4-diethylthioxanthonone, the amount of 2,4-diethylthioxanthonone being 1% of the mass of acrylic acid. The mixture was subjected to UV polymerization for 30min under UV irradiation at a wavelength of 370nm and vacuum dried at 70℃ for 11h to obtain an ionic liquid gel. 6g of the ionic liquid gel was immersed in 200mL of 0.15mol / L phosphotungstic acid ethanol solution and stirred for 24h. The mixture was filtered and vacuum dried and cured at 70℃ and 500Pa for 11h to obtain an ionic liquid gel catalyst supported on phosphotungstic acid.

[0071] The other steps are the same as in Example 3.

[0072] The purity of 1,1-bis(tert-butylperoxy)-3,3,5-trimethylcyclohexane was 30.27%, and the yield was 40.92%. The liquid chromatography results of 1,1-bis(tert-butylperoxy)-3,3,5-trimethylcyclohexane are shown below. Figure 8 And Table 5.

[0073] Table 5. Liquid chromatography data results for Comparative Example 2

[0074]

[0075] Comparative Example 3

[0076] Without adding the mixed solution of 1-butyl-3-methylimidazolium chloride and acrylic acid, the other steps are the same as in Example 3.

[0077] The purity of 1,1-bis(tert-butylperoxy)-3,3,5-trimethylcyclohexane was 36.89%, and the yield was 42.28%. The liquid chromatography results of 1,1-bis(tert-butylperoxy)-3,3,5-trimethylcyclohexane are shown below. Figure 9 And Table 6.

[0078] Table 6. Liquid Chromatography Data Results of Comparative Example 3

[0079]

Claims

1. A MOF-confined heteropolyacid-ionic liquid gel catalyst characterized in that The structure is a heteropoly acid confined by MOF as a core, and a pH-responsive ionic liquid gel is coated outside the core; wherein the MOF is UiO-66-SO3H, the heteropoly acid is phosphotungstic acid, and the pH-responsive ionic liquid gel is a 1-butyl-3-methylimidazolium chloride and polyacrylic acid complex; The preparation method of the MOF-confined heteropoly acid-ionic liquid gel catalyst comprises the following steps: (1) MOF is immersed in a phosphotungstic acid ethanol solution, stirred, filtered, and vacuum dried and solidified to obtain MOF particles loaded with phosphotungstic acid; (2) The MOF particles loaded with phosphotungstic acid are dispersed in a mixed solution under a nitrogen condition, a photoinitiator is added for UV polymerization, and vacuum drying is performed to obtain the MOF-confined heteropoly acid-ionic liquid gel catalyst; The mixed solution in step (2) is a mixed solution of 1-butyl-3-methylimidazolium chloride and acrylic acid.

2. The MOF-confined heteropolyacid-ionic liquid gel catalyst of claim 1, wherein In step (1), the preparation method of the MOF is to add UiO-66-NH2 and 1,3-propane sultone into N,N-dimethylformamide, react at 60-80 DEG C for 12-24 h, filter, and dry to obtain the MOF, wherein the mass ratio of UiO-66-NH2 to 1,3-propane sultone is 1:1-1.2, the ratio of UiO-66-NH2 to N,N-dimethylformamide is 1:15-20, UiO-66-NH2 is measured in grams, and N,N-dimethylformamide is measured in milliliters; the concentration of the phosphotungstic acid ethanol solution is 0.1-0.2 mol / L; the ratio of the MOF to the phosphotungstic acid ethanol solution is 6:150-200, the MOF is measured in grams, and the phosphotungstic acid ethanol solution is measured in milliliters; the stirring time is 12-24 h, the vacuum degree for vacuum drying and solidification is 100-1000 Pa, the vacuum drying and solidification temperature is 60-80 DEG C, and the vacuum drying and solidification time is 10-12 h.

3. The MOF-confined heteropolyacid-ionic liquid gel catalyst of claim 1, wherein In step (2), the mass ratio of 1-butyl-3-methylimidazolium chloride to acrylic acid is 1:1-4; the mass of the MOF particles loaded with phosphotungstic acid is 10-20% of the mass of the mixed solution; the photoinitiator is 2,4-diethylthioxanthone, and the amount of the photoinitiator is 1-3% of the mass of the acrylic acid; the ultraviolet wavelength for UV polymerization is 365-385 nm, the UV polymerization time is 30-60 min; the vacuum drying temperature is 50-70 DEG C, and the vacuum drying time is 11-13 h.

4. A process for the preparation of organic peroxides based on the MOF-confined heteropolyacid-ionic liquid gel catalyst of claim 1, characterized in that The method comprises the following steps: (a) adding the MOF-confined heteropoly acid-ionic liquid gel catalyst into a t-butyl alcohol aqueous solution, and then adding a hydrogen peroxide aqueous solution, to obtain a t-butyl hydroperoxide aqueous solution containing the MOF-confined heteropoly acid-ionic liquid gel catalyst; (b) adding 3,3,5-trimethylcyclohexanone and a desensitizer to the t-butyl hydroperoxide aqueous solution containing the MOF-confined heteropoly acid-ionic liquid gel catalyst obtained in step (a) to carry out a reaction, filtering to obtain a MOF-confined heteropoly acid-ionic liquid gel catalyst and a reaction liquid, recycling the MOF-confined heteropoly acid-ionic liquid gel catalyst, and removing a lower aqueous phase by static layer separation to obtain 1,1-bis(t-butylperoxy)-3,3,5-trimethylcyclohexane crude product, and sequentially carrying out alkali washing, water washing, drying and filtering on the 1,1-bis(t-butylperoxy)-3,3,5-trimethylcyclohexane crude product to obtain 1,1-bis(t-butylperoxy)-3,3,5-trimethylcyclohexane.

5. The process for the preparation of organic peroxides based on MOF confined heteropolyacid-ionic liquid gel catalyst according to claim 4, characterized in that The concentration of the t-butyl alcohol aqueous solution in step (a) is 70-85wt%, and the concentration of the hydrogen peroxide aqueous solution is 40-60wt%; the molar ratio of hydrogen peroxide in the hydrogen peroxide aqueous solution to t-butyl alcohol in the t-butyl alcohol aqueous solution is 1.05-1.30:1; the reaction temperature is 50-70℃, and the reaction time is 3-6h.

6. The process for the preparation of organic peroxides based on MOF confined heteropolyacid-ionic liquid gel catalyst according to claim 4, characterized in that The addition time of the MOF-confined heteropoly acid-ionic liquid gel catalyst in step (a) is 5-10min, and the mass ratio of the MOF-confined heteropoly acid-ionic liquid gel catalyst to the t-butyl alcohol aqueous solution is 0.2-0.3:

1.

7. The process for the preparation of organic peroxides based on MOF confined heteropolyacid-ionic liquid gel catalyst according to claim 4, characterized in that The desensitizer in step (b) is one of normal alkanes, isomeric alkanes, ethylbenzene or liquid paraffin; the mass ratio of the desensitizer to 3,3,5-trimethylcyclohexanone is 0.09-0.10:1; the reaction temperature is room temperature, and the reaction time is 3-5h.

8. The process for the preparation of organic peroxides based on MOF confined heteropolyacid-ionic liquid gel catalyst according to claim 4, characterized in that The molar ratio of t-butyl alcohol in the t-butyl alcohol aqueous solution to 3,3,5-trimethylcyclohexanone is 2.1-2.4:

1.

9. The process for the preparation of organic peroxides based on MOF confined heteropolyacids-ionic liquid gel catalyst according to claim 4, characterized in that The alkali washing in step (b) is adding a 5-6wt% sodium hydroxide solution to the 1,1-bis(t-butylperoxy)-3,3,5-trimethylcyclohexane crude product to stir for 15-30min, and then taking the organic phase by static layer separation; the water washing is adding deionized water to the organic phase obtained after the alkali washing to stir for 15-30min, and then taking the organic phase by static layer separation; The drying is carried out using anhydrous magnesium sulfate.

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