Process for the preparation of 1,1-bis(tert-butylperoxy)-3,3,5-trimethylcyclohexane

Abstract

The application belongs to the technical field of carbon ring compounds, and particularly relates to a preparation method of 1,1-bis(tert-butyl peroxy)-3,3,5-trimethylcyclohexane. A mixed solution of tert-butyl hydroperoxide aqueous solution and a temperature-sensitive hybrid catalyst is mixed with a mixed solution of 3,3,5-trimethylcyclohexanone and isomeric alkanes in a micro-mixer to obtain a mixed solution, and the mixed solution is introduced into a micro-channel reactor to perform reaction; after the reaction is completed, the reaction is quenched by heating, the temperature-sensitive hybrid catalyst is recovered by filtration and recycling; after filtration, the obtained material is subjected to gas-liquid separation, and the liquid phase is collected; the liquid phase is allowed to stand and separate into layers, and the upper organic phase is collected, and the organic phase is subjected to alkaline washing, water washing, drying and filtration in sequence to obtain 1,1-bis(tert-butyl peroxy)-3,3,5-trimethylcyclohexane. The application solves the problems of the risk of explosion caused by thermal decomposition of peroxide, the difficulty in recycling of homogeneous catalysts and the low efficiency of intermittent production in the traditional process.

Description

Technical Field

[0001] This invention belongs to the field of carbocyclic compound technology, specifically relating to a method for preparing 1,1-bis(tert-butylperoxy)-3,3,5-trimethylcyclohexane. Background Technology

[0002] 1,1-Bis(tert-butylperoxy)-3,3,5-trimethylcyclohexane (commonly referred to as bis(tert-butylperoxy)trimethylcyclohexane or TBPMC) is an important liquid organic peroxide, mainly used as a free radical initiator, especially in the field of crosslinking (vulcanization) of polymer materials, such as the high-temperature vulcanization of silicone rubber, ethylene propylene rubber, and polyethylene. The preparation of this compound is based on the condensation reaction of 3,3,5-trimethylcyclohexanone (TMC) and tert-butyl hydroperoxide (TBHP) in the presence of an acidic catalyst.

[0003] The traditional synthesis method of TBPMC uses concentrated sulfuric acid as a catalyst. Although there have been technological improvements, equipment corrosion and serious safety risks still exist. The main reason is that the reaction itself is exothermic, and the acid dropping process will further increase the system temperature, leading to violent decomposition, combustion or even explosion of raw materials, products or possible intermediates. At the same time, the increase in side reactions may generate more unstable peroxides or free radicals, exacerbating the risks.

[0004] Chinese patent CN114014791A discloses a method for preparing 1,1-bis(tert-butylperoxy)cyclohexane, which uses solid acid catalysis to synthesize the target product 1,1-bis(tert-butylperoxy)cyclohexane. However, the solid acid in this patent suffers from problems such as dissolution and agglomeration; furthermore, the batch production method results in low production efficiency and significant safety hazards. Summary of the Invention

[0005] The purpose of this invention is to provide a method for preparing 1,1-bis(tert-butylperoxy)-3,3,5-trimethylcyclohexane, which solves the problems of easy explosion risk of peroxide thermal decomposition, difficulty in recovering homogeneous catalyst and low efficiency of intermittent production in traditional processes.

[0006] The method for preparing 1,1-bis(tert-butylperoxy)-3,3,5-trimethylcyclohexane according to the present invention includes the following steps:

[0007] (1) The mixture of tert-butyl hydrogen peroxide aqueous solution and thermosensitive hybrid catalyst and the mixture of 3,3,5-trimethylcyclohexanone and isoparaffin are added to a micro mixer and mixed evenly. The resulting mixed solution is then introduced into a microchannel reactor for reaction. After the reaction is completed, the reaction is quenched by heating. The thermosensitive hybrid catalyst is filtered and recovered for recycling. The material obtained after filtration is separated into gas and liquid phases and the liquid phase is collected.

[0008] (2) The liquid phase obtained in step (1) was allowed to stand and separate into layers. The upper organic phase was taken and then washed with alkali, washed with water, dried and filtered to obtain 1,1-bis(tert-butylperoxy)-3,3,5-trimethylcyclohexane.

[0009] In step (1), the mass ratio of tert-butyl hydroperoxide aqueous solution to thermosensitive hybrid catalyst is 1:0.2-0.4, the mass ratio of 3,3,5-trimethylcyclohexanone to isoalkanes is 1:0.08-0.12, the flow rate of the mixture of 3,3,5-trimethylcyclohexanone and isoalkanes is 0.5-1 mL / min, the flow rate ratio of the mixture of 3,3,5-trimethylcyclohexanone and isoalkanes to the mixture of tert-butyl hydroperoxide aqueous solution and thermosensitive hybrid catalyst is 1:2.2-2.4, the concentration of tert-butyl hydroperoxide aqueous solution is 70-80 wt.%, the isoalkanes are a mixture of C13-C16 isoalkanes, and the purity of 3,3,5-trimethylcyclohexanone is ≥99 wt.%.

[0010] In step (1), the reaction temperature is 10-25℃ and the reaction time is 20-30 min; the temperature is then raised to 35-40℃.

[0011] The preparation method of the temperature-sensitive hybrid catalyst in step (1) includes the following steps:

[0012] (a) MIL-101(Cr) was activated to obtain activated MIL-101(Cr); the activated MIL-101(Cr) was immersed in phosphotungstic acid ethanol solution, stirred, filtered, and vacuum dried to obtain HPA@MIL-101(Cr) particles.

[0013] (b) Under nitrogen conditions, HPA@MIL-101(Cr) particles, N-isopropylacrylamide monomer, chain transfer agent and initiator were dispersed in an ethanol aqueous solution for polymerization reaction, filtered and vacuum dried to obtain the thermosensitive hybrid catalyst PNIPAM / HPA@MIL-101(Cr).

[0014] The activation step in step (a) involves adding MIL-101(Cr) to N,N-dimethylformamide and stirring at 60-80°C for 2-4 hours, followed by filtration. The resulting solid is then added to an aqueous ethanol solution and stirred at 60-80°C for 2-4 hours, followed by filtration to obtain activated MIL-101(Cr). The mass ratio of MIL-101(Cr) to N,N-dimethylformamide is 0.3-0.5:1, the mass ratio of MIL-101(Cr) to the aqueous ethanol solution is 0.3-0.5:1, and the concentration of the aqueous ethanol solution is 80-95 wt.%.

[0015] In step (a), the ratio of activated MIL-101(Cr) to phosphotungstic acid ethanol solution is 1:20-24, wherein activated MIL-101(Cr) is expressed in g and phosphotungstic acid ethanol solution is expressed in mL; the concentration of phosphotungstic acid ethanol solution is 0.1-0.2 mol / L.

[0016] In step (a), the stirring time is 12-14h, the vacuum degree of vacuum drying is 100-1000Pa, the vacuum drying temperature is 60-80℃, and the vacuum drying time is 10-12h.

[0017] In step (b), the chain transfer agent is 2-[dodecylthio(thiocarbonyl)thio]-2-methylpropionic acid, and the initiator is azobisisobutyramidine dihydrochloride.

[0018] In step (b), the ratio of HPA@MIL-101(Cr) particles to ethanol-water solution is 5-6:200-250, where HPA@MIL-101(Cr) particles are expressed in g and ethanol-water solution in mL; the concentration of ethanol-water solution is 80-95 wt.%; the mass ratio of HPA@MIL-101(Cr) particles, N-isopropylacrylamide monomer (NIPAM), chain transfer agent and initiator is 10-12:40-50:1:0.2-0.3.

[0019] In step (b), the polymerization reaction temperature is 50-70℃ and the polymerization reaction time is 12-24h; the vacuum drying temperature is 50-70℃ and the vacuum drying time is 12-18h.

[0020] In step (2), alkaline washing involves adding a 4-6 wt.% sodium hydroxide solution and stirring for 15-30 minutes, then allowing the mixture to stand and separate into layers to obtain the organic phase; water washing involves adding deionized water and stirring for 15-30 minutes, then allowing the mixture to stand and separate into layers to obtain the organic phase; and drying involves using anhydrous magnesium sulfate for drying.

[0021] The synthetic route of this invention is as follows:

[0022]

[0023] This invention involves mixing a mixture of tert-butyl hydrogen peroxide aqueous solution and a thermosensitive hybrid catalyst with a mixture of 3,3,5-trimethylcyclohexanone and isomeric alkanes in a micromixer. The resulting mixed solution is then introduced into a microchannel reactor for reaction at a temperature of 10-25°C. At this temperature, the poly(N-isopropylacrylamide) chains swell, exposing acidic active sites, and the catalyst is uniformly dispersed in the mixed solution, achieving homogeneous and highly efficient catalysis. After the reaction, the temperature is raised to 35-40°C to quench the reaction. At this temperature, the PNIPAM chains hydrophobically shrink, and the catalyst aggregates. The thermosensitive hybrid catalyst is then collected and recycled through a ceramic membrane filter. The filtered material is then subjected to gas-liquid separation, and the liquid phase is collected. The liquid phase is allowed to stand and separate into layers. The upper organic phase is then taken and subjected to alkali washing, water washing, drying, and filtration to obtain 1,1-bis(tert-butylperoxy)-3,3,5-trimethylcyclohexane.

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

[0025] (1) The PNIPAM / HPA@MIL-101(Cr) catalyst provided by this invention combines the characteristics and synergistic advantages of phosphotungstic acid, thermosensitive PNIPAM polymer, and porous MOF material. The strong acidity and strong oxidizing properties of phosphotungstic acid can promote the formation of peroxy bonds, improving catalytic activity and selectivity for disubstituted target products; however, it has high solubility in water, exhibiting extremely strong polar solvent-induced leaching characteristics; while MIL-101(Cr)… With its large specific surface area, tunable pore structure, and excellent chemical / thermal stability, PNIPAM can confine phosphotungstic acid within the pores of MIL-101(Cr), effectively preventing the leaching, loss, or aggregation of the active components during use. Simultaneously, its metal nodes (Cr clusters) possess a certain degree of Lewis acidity, forming an acidic synergistic catalysis with the Brønsted acidity of phosphotungstic acid, thus enhancing catalytic efficiency. The PNIPAM network, encasing the MIL-101(Cr) layer, acts as both a "glue" and a "protective layer," further enhancing the mechanical and chemical stability of the composite material, reducing the loss of active components, and mitigating the decomposition of the support under harsh reaction conditions. Furthermore, the thermosensitive behavior of PNIPAM is directly coupled with the catalytic reaction process, enabling intelligent and reversible "on / off" control of the reaction. This provides a foundation for precisely controlling reaction time, preventing over-reaction, and facilitating the easy separation of products from the catalyst.

[0026] In summary, the PNIPAM / HPA@MIL-101(Cr) catalyst is an integrated catalyst combining catalysis, separation, and intelligent control. Its synergistic effect is primarily due to: ① Catalytic synergy: the bifunctional acidic catalysis of phosphotungstic acid and MIL-101(Cr); ② Stability synergy: the rigid framework of MIL-101(Cr) provides structural support for phosphotungstic acid and PNIPAM, while the PNIPAM polymer network acts as a physical barrier, enhancing the mechanical and chemical stability of the material and preventing the loss of active components; ③ Intelligent control and separation / recovery synergy: the temperature-sensitive switch of PNIPAM controls the catalytic reaction process of phosphotungstic acid, and the phase transition of the hybrid system enables convenient catalyst recovery.

[0027] (2) The present invention uses a microchannel reactor to continuously synthesize TBPMC, which has the advantages of precise temperature control, efficient mass transfer, and safety controllability, and realizes the green, safe, efficient and intelligent continuous production of 1,1-bis(tert-butylperoxy)-3,3,5-trimethylcyclohexane.

[0028] (3) After the reaction is completed, the temperature is raised to 35-40℃. The PNIPAM chain in the thermosensitive hybrid catalyst collapses, causing the catalyst particles to aggregate hydrophobically and form larger flocs or particles. This temperature-triggered, reversible aggregation behavior allows the originally nano-sized catalyst to be efficiently separated from the reaction liquid by a simple ceramic membrane filtration method. That is, the thermosensitivity of PNIPAM endows the entire hybrid catalyst with the excellent characteristics of "homogeneous catalysis and heterogeneous separation", realizing the convenient recovery and recycling of the catalyst, effectively avoiding the recovery problem of traditional homogeneous catalysts (such as H2SO4). The catalyst can be recycled more than 20 times, while reducing equipment corrosion and waste acid treatment problems, which is in line with the concept of green chemistry and sustainability. Attached Figure Description

[0029] Figure 1 This is the liquid chromatogram of the product in Example 1.

[0030] Figure 2 This is the H-spectrum NMR spectrum of the product in Example 1.

[0031] Figure 3 This is the liquid chromatogram of the product in Example 2.

[0032] Figure 4 This is the H-spectrum NMR spectrum of the product in Example 2.

[0033] Figure 5 This is the liquid chromatogram of the product in Example 3.

[0034] Figure 6 This is the H-spectrum NMR spectrum of the product in Example 3.

[0035] Figure 7This is the liquid chromatogram of the product in Comparative Example 1.

[0036] Figure 8 This is the liquid chromatogram of the product in Comparative Example 2.

[0037] Figure 9 This is the liquid chromatogram of the product in Comparative Example 3. Detailed Implementation

[0038] The present invention will be further described below with reference to embodiments.

[0039] Example 1

[0040] The preparation method of the temperature-sensitive hybrid catalyst includes the following steps:

[0041] (a) 5g of MIL-101(Cr) was added to 15g of N,N-dimethylformamide and stirred at 70°C for 3 hours. After filtration, the solid obtained was added to 15g of 90wt.% ethanol aqueous solution and stirred at 70°C for 3 hours. After filtration, activated MIL-101(Cr) was obtained. The activated MIL-101(Cr) was immersed in 120mL of 0.1mol / L phosphotungstic acid ethanol solution and stirred at room temperature for 12h. After filtration, it was vacuum dried at 70°C and 500Pa for 10h to obtain HPA@MIL-101(Cr) particles.

[0042] (b) Under nitrogen conditions, 5.5 g of HPA@MIL-101(Cr) particles, 23 g of N-isopropylacrylamide monomer, 0.5 g of 2-[dodecylthio(thiocarbonyl)thio]-2-methylpropionic acid and 0.12 g of azobisisobutyramidine dihydrochloride were dispersed in 220 mL of 90 wt.% ethanol aqueous solution. The mixture was heated to 60 °C and stirred for 20 h for polymerization. After the reaction was completed, the mixture was filtered and dried under vacuum at 60 °C for 15 h to obtain the thermosensitive hybrid catalyst PNIPAM / HPA@MIL-101(Cr).

[0043] The preparation method of 1,1-bis(tert-butylperoxy)-3,3,5-trimethylcyclohexane includes the following steps:

[0044] (1) Using precise control via an injection pump, a mixture of 75 wt.% tert-butyl hydrogen peroxide aqueous solution and thermosensitive hybrid catalyst (flow rate: 1.1 mL / min) and a mixture of 3,3,5-trimethylcyclohexanone and isoparaffins (flow rate: 0.5 mL / min) were added to a micro mixer and mixed evenly. The resulting mixed solution was then introduced into a microchannel reactor for reaction at a temperature of 15 °C and a residence time of 25 min. After the reaction was completed, the temperature was raised to 35 °C to quench the reaction. The thermosensitive hybrid catalyst was then collected and recycled by a ceramic membrane filter. The filtered material was separated into gas and liquid phases by a gas-liquid separator, and the liquid phase was collected. The mass ratio of tert-butyl hydrogen peroxide aqueous solution to thermosensitive hybrid catalyst was 1:0.2, and the mass ratio of 3,3,5-trimethylcyclohexanone to isoparaffins was 1:0.1. The isoparaffins were a mixture of C13-C16 isoparaffins (Shanghai Baika Chemical Technology Co., Ltd.).

[0045] (2) The liquid phase obtained in step (1) was allowed to stand and separate into layers. The upper organic phase was taken, and a 6 wt.% sodium hydroxide solution was added to the organic phase and stirred for 15 min. The organic phase was allowed to stand and separate into layers again. Deionized water was added to the organic phase and stirred for 15 min. The organic phase was allowed to stand and separate into layers again. The organic phase was dried with anhydrous magnesium sulfate and filtered to obtain the product 1,1-bis(tert-butylperoxy)-3,3,5-trimethylcyclohexane with a purity of 88.88% and a yield of 90.96%. The liquid chromatography results of the product are shown in the figure. Figure 1 See Table 1, H-NMR spectrum. Figure 2 .

[0046] Table 1. Liquid Chromatography Data of Example 1

[0047]

[0048] Example 2

[0049] The preparation method of the temperature-sensitive hybrid catalyst includes the following steps:

[0050] (a) 5g of MIL-101(Cr) was added to 13g of N,N-dimethylformamide and stirred at 60°C for 4 hours. After filtration, the solid obtained was added to 13g of an 80wt.% aqueous ethanol solution and stirred at 60°C for 4 hours. After filtration, activated MIL-101(Cr) was obtained. The activated MIL-101(Cr) was immersed in 100mL of a 0.15mol / L phosphotungstic acid ethanol solution and stirred at room temperature for 13h. After filtration, it was vacuum dried at 60°C and 100Pa for 11h to obtain HPA@MIL-101(Cr) particles.

[0051] (b) Under nitrogen conditions, 5 g of HPA@MIL-101(Cr) particles, 20 g of N-isopropylacrylamide monomer, 0.5 g of 2-[dodecylthio(thiocarbonyl)thio]-2-methylpropionic acid and 0.1 g of azobisisobutyramidine dihydrochloride were dispersed in 200 mL of 80 wt.% ethanol aqueous solution. The mixture was heated to 50 °C and stirred for 24 h for polymerization. After the reaction was completed, the mixture was filtered and dried under vacuum at 50 °C for 18 h to obtain the thermosensitive hybrid catalyst PNIPAM / HPA@MIL-101(Cr).

[0052] The preparation method of 1,1-bis(tert-butylperoxy)-3,3,5-trimethylcyclohexane includes the following steps:

[0053] (1) Using precise control via an injection pump, a mixture of 70 wt.% tert-butyl hydrogen peroxide aqueous solution and thermosensitive hybrid catalyst (flow rate: 1.92 mL / min) and a mixture of 3,3,5-trimethylcyclohexanone and isoparaffins (flow rate: 0.8 mL / min) were added to a micro mixer and mixed evenly. The resulting mixed solution was then introduced into a microchannel reactor for reaction at a temperature of 10 °C and a residence time of 30 min. After the reaction was completed, the temperature was raised to 40 °C to quench the reaction. The thermosensitive hybrid catalyst was then collected and recycled by a ceramic membrane filter. The filtered material was separated into gas and liquid phases by a gas-liquid separator, and the liquid phase was collected. The mass ratio of tert-butyl hydrogen peroxide aqueous solution to thermosensitive hybrid catalyst was 1:0.4, and the mass ratio of 3,3,5-trimethylcyclohexanone to isoparaffins was 1:0.08. The isoparaffins were a mixture of C13-C16 isoparaffins (Shanghai Baika Chemical Technology Co., Ltd.).

[0054] (2) The liquid phase obtained in step (1) was allowed to stand and separate into layers. The upper organic phase was taken, and a 4 wt.% sodium hydroxide solution was added to the organic phase and stirred for 30 min. After standing and separating into layers, the organic phase was taken, and deionized water was added to the organic phase and stirred for 25 min. After standing and separating into layers, the organic phase was taken, dried with anhydrous magnesium sulfate, and filtered to obtain the product 1,1-bis(tert-butylperoxy)-3,3,5-trimethylcyclohexane with a purity of 87.58% and a yield of 89.83%. The liquid chromatography results of the product are shown in […]. Figure 3 See Table 2, H-NMR spectrum. Figure 4 .

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

[0056]

[0057] Example 3

[0058] The preparation method of the temperature-sensitive hybrid catalyst includes the following steps:

[0059] (a) 5g of MIL-101(Cr) was added to 10g of N,N-dimethylformamide and stirred at 80°C for 2 hours. After filtration, the solid obtained was added to 10g of 95wt.% ethanol aqueous solution and stirred at 80°C for 2 hours. After filtration, activated MIL-101(Cr) was obtained. The activated MIL-101(Cr) was immersed in 110mL of 0.2mol / L phosphotungstic acid ethanol solution and stirred at room temperature for 14h. After filtration, it was vacuum dried at 80°C and 1000Pa for 12h to obtain HPA@MIL-101(Cr) particles.

[0060] (b) Under nitrogen atmosphere, 6 g of HPA@MIL-101(Cr) particles, 25 g of N-isopropylacrylamide monomer, 0.5 g of 2-[dodecylthio(thiocarbonyl)thio]-2-methylpropionic acid and 0.15 g of azobisisobutyramidine dihydrochloride were dispersed in 250 mL of 95 wt.% ethanol aqueous solution. The mixture was heated to 70 °C and stirred for 12 h for polymerization. After the reaction was completed, the mixture was filtered and dried under vacuum at 70 °C for 12 h to obtain the thermosensitive hybrid catalyst PNIPAM / HPA@MIL-101(Cr).

[0061] The preparation method of 1,1-bis(tert-butylperoxy)-3,3,5-trimethylcyclohexane includes the following steps:

[0062] (1) By precise control of the injection pump, a mixture of 80 wt.% tert-butyl hydrogen peroxide aqueous solution and thermosensitive hybrid catalyst (flow rate: 2.3 mL / min) and a mixture of 3,3,5-trimethylcyclohexanone and isoparaffin (flow rate: 1 mL / min) were added to a micro mixer and mixed evenly. The resulting mixed solution was then introduced into a microchannel reactor for reaction at a temperature of 25 °C and a residence time of 20 min. After the reaction was completed, the temperature was raised to 37 °C to quench the reaction. The thermosensitive hybrid catalyst was then collected and recycled by a ceramic membrane filter. The filtered material was separated into gas and liquid phases by a gas-liquid separator, and the liquid phase was collected. The mass ratio of tert-butyl hydrogen peroxide aqueous solution to thermosensitive hybrid catalyst was 1:0.3, the mass ratio of 3,3,5-trimethylcyclohexanone to isoparaffin was 1:0.12, and the isoparaffin was a mixture of C13-C16 isoparaffins (Shanghai Baika Chemical Technology Co., Ltd.).

[0063] (2) The liquid phase obtained in step (1) was allowed to stand and separate into layers. The upper organic phase was taken, and a 5 wt.% sodium hydroxide solution was added to the organic phase and stirred for 20 min. After standing and separating into layers, the organic phase was taken, and deionized water was added to the organic phase and stirred for 30 min. After standing and separating into layers, the organic phase was dried with anhydrous magnesium sulfate and filtered to obtain the product 1,1-bis(tert-butylperoxy)-3,3,5-trimethylcyclohexane with a purity of 91.07% and a yield of 92.37%. The liquid chromatography results of the product are shown in […]. Figure 5 See Table 3, H-NMR spectrum. Figure 6 .

[0064] Table 3. Liquid chromatography data for Example 3

[0065]

[0066] Comparative Example 1

[0067] Without adding N-isopropylacrylamide monomer, the other steps were the same as in Example 3, with a purity of 44.37% and a yield of 62.86%. The liquid chromatography results of the product are shown below. Figure 7 And Table 4.

[0068] Table 4. Liquid Chromatography Data of Comparative Example 1

[0069]

[0070] Comparative Example 2

[0071] Under nitrogen atmosphere, 25 g of N-isopropylacrylamide monomer, 0.5 g of 2-[dodecylthio(thiocarbonyl)thio]-2-methylpropionic acid, and 0.15 g of azobisisobutyramidine dihydrochloride were dispersed in 250 mL of 95 wt.% ethanol aqueous solution. The mixture was heated to 70 °C and stirred for 12 h for polymerization. After the reaction was completed, the mixture was filtered and vacuum dried at 70 °C for 12 h to obtain PNIPAM polymer. The PNIPAM polymer was then immersed in 110 mL of 0.2 mol / L phosphotungstic acid ethanol solution and stirred at room temperature for 14 h. After filtration, the mixture was vacuum dried at 80 °C and 1000 Pa for 12 h to obtain HPA@PNIPAM catalyst.

[0072] The other steps were the same as in Example 3, with a purity of 15.64% and a yield of 23.59%. The liquid chromatography results of the product are shown below. Figure 8 See Table 5.

[0073] Table 5. Liquid Chromatography Data of Comparative Example 2

[0074]

[0075] Comparative Example 3

[0076] Without adding phosphotungstic acid ethanol solution, the other steps were the same as in Example 3, with a purity of 11.46% and a yield of 18.73%. The liquid chromatography results of the product are shown below. Figure 9 See Table 6.

[0077] Table 6. Liquid Chromatography Data of Comparative Example 3

[0078]

Claims

1. A method for preparing 1,1-bis(tert-butylperoxy)-3,3,5-trimethylcyclohexane, characterized in that... Includes the following steps: (1) The mixture of tert-butyl hydrogen peroxide aqueous solution and thermosensitive hybrid catalyst and the mixture of 3,3,5-trimethylcyclohexanone and isoparaffin are added to a micro mixer and mixed evenly. The resulting mixed solution is then introduced into a microchannel reactor for reaction. After the reaction is completed, the reaction is quenched by heating. The thermosensitive hybrid catalyst is filtered and recovered for recycling. The material obtained after filtration is separated into gas and liquid phases and the liquid phase is collected. (2) The liquid phase obtained in step (1) was allowed to stand and separate into layers. The upper organic phase was taken and subjected to alkali washing, water washing, drying and filtration in sequence to obtain 1,1-bis(tert-butylperoxy)-3,3,5-trimethylcyclohexane. In step (1), the reaction temperature is 10-25℃, and the temperature is raised to 35-40℃; The preparation method of the temperature-sensitive hybrid catalyst in step (1) includes the following steps: (a) MIL-101(Cr) was activated to obtain activated MIL-101(Cr); the activated MIL-101(Cr) was immersed in phosphotungstic acid ethanol solution, stirred, filtered, and vacuum dried to obtain HPA@MIL-101(Cr) particles. (b) Under nitrogen conditions, HPA@MIL-101(Cr) particles, N-isopropylacrylamide monomer, chain transfer agent and initiator were dispersed in an ethanol aqueous solution for polymerization reaction, filtered and vacuum dried to obtain the thermosensitive hybrid catalyst PNIPAM / HPA@MIL-101(Cr).

2. The method for preparing 1,1-bis(tert-butylperoxy)-3,3,5-trimethylcyclohexane according to claim 1, characterized in that... In step (1), the mass ratio of tert-butyl hydrogen peroxide aqueous solution to thermosensitive hybrid catalyst is 1:0.2-0.4, the mass ratio of 3,3,5-trimethylcyclohexanone to isoalkanes is 1:0.08-0.12, the flow rate of the mixture of 3,3,5-trimethylcyclohexanone and isoalkanes is 0.5-1 mL / min, the flow rate ratio of the mixture of 3,3,5-trimethylcyclohexanone and isoalkanes to the mixture of tert-butyl hydrogen peroxide aqueous solution and thermosensitive hybrid catalyst is 1:2.2-2.4, the concentration of tert-butyl hydrogen peroxide aqueous solution is 70-80 wt.%, and the isoalkanes are a mixture of C13-C16 isoalkanes.

3. The method for preparing 1,1-bis(tert-butylperoxy)-3,3,5-trimethylcyclohexane according to claim 1, characterized in that... The reaction time in step (1) is 20-30 min.

4. The method for preparing 1,1-bis(tert-butylperoxy)-3,3,5-trimethylcyclohexane according to claim 1, characterized in that... The activation step in step (a) involves adding MIL-101(Cr) to N,N-dimethylformamide and stirring at 60-80°C for 2-4 hours, followed by filtration. The resulting solid is then added to an aqueous ethanol solution and stirred at 60-80°C for 2-4 hours, followed by filtration to obtain activated MIL-101(Cr). The mass ratio of MIL-101(Cr) to N,N-dimethylformamide is 0.3-0.5:1, the mass ratio of MIL-101(Cr) to the aqueous ethanol solution is 0.3-0.5:1, and the concentration of the aqueous ethanol solution is 80-95 wt.%.

5. The method for preparing 1,1-bis(tert-butylperoxy)-3,3,5-trimethylcyclohexane according to claim 1, characterized in that... In step (a), the ratio of activated MIL-101(Cr) to phosphotungstic acid ethanol solution is 1:20-24, wherein activated MIL-101(Cr) is expressed in g and phosphotungstic acid ethanol solution is expressed in mL; the concentration of phosphotungstic acid ethanol solution is 0.1-0.2 mol / L.

6. The method for preparing 1,1-bis(tert-butylperoxy)-3,3,5-trimethylcyclohexane according to claim 1, characterized in that... In step (a), the stirring time is 12-14h, the vacuum degree of vacuum drying is 100-1000Pa, the vacuum drying temperature is 60-80℃, and the vacuum drying time is 10-12h.

7. The method for preparing 1,1-bis(tert-butylperoxy)-3,3,5-trimethylcyclohexane according to claim 1, characterized in that... In step (b), the chain transfer agent is 2-[dodecylthio(thiocarbonyl)thio]-2-methylpropionic acid, and the initiator is azobisisobutyramidine dihydrochloride.

8. The method for preparing 1,1-bis(tert-butylperoxy)-3,3,5-trimethylcyclohexane according to claim 1, characterized in that... In step (b), the ratio of HPA@MIL-101(Cr) particles to ethanol-water solution is 5-6:200-250, where HPA@MIL-101(Cr) particles are expressed in g and ethanol-water solution in mL; the concentration of ethanol-water solution is 80-95 wt.%; the mass ratio of HPA@MIL-101(Cr) particles, N-isopropylacrylamide monomer, chain transfer agent and initiator is 10-12:40-50:1:0.2-0.

3.

9. The method for preparing 1,1-bis(tert-butylperoxy)-3,3,5-trimethylcyclohexane according to claim 1, characterized in that... In step (b), the polymerization reaction temperature is 50-70℃ and the polymerization reaction time is 12-24h; the vacuum drying temperature is 50-70℃ and the vacuum drying time is 12-18h.

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