Peroxy cycloalkane as well as preparation method and application thereof

Abstract

The invention provides a peroxide cycloalkane organic peroxide: # imgabs0 #, and a preparation method of the peroxide cycloalkane organic peroxide. The compound can be obtained by reacting 2-butanone and hydrogen peroxide under the catalysis of acid. The peroxide cycloalkane organic peroxide is applied as a polymerization initiator, a plastic degradation agent and a rubber vulcanizing agent. The peroxide cycloalkane organic peroxide has many active groups and high active oxygen, the reaction product does not contain volatile matters with pungent smell, and the smell of the product can be greatly reduced; the flash point is low and the safety is high. The microflow reaction is adopted, the reaction speed is high, the yield is high, and the production process is safe.

Description

Technical Field

[0001] The invention belongs to the technical field of chemical synthesis, and specifically relates to a peroxycycloalkane and a preparation method and application thereof. Background Art

[0002] Organic peroxides are an important and relatively special class of chemical substances with strong oxidizing properties. The peroxide bonds in organic peroxide molecules are easily decomposed into active free radicals and oxygen when heated. Due to their ability to release free radicals, they are widely used in industries such as polypropylene, polyethylene, polyvinyl chloride, polystyrene, polyester, synthetic resins, synthetic rubber, and other industries. Free radical polymerization is an effective method for large-scale production of various olefin polymers. The advantages of free radical polymerization are that there are many types of polymerizable monomers, mild and easy-to-control reaction conditions, and it is easy to achieve industrial production. About 70% of olefin polymers are achieved through free radical polymerization.

[0003] Another use of organic peroxides is as a degradation agent for high-melting polypropylene. The earliest use was of chain peroxides, which were added in large amounts, produced a high amount of volatiles after the reaction, and most of them were volatiles with a strong pungent odor. Therefore, the resulting high-melting index polypropylene had a strong smell and was potentially carcinogenic. The peroxycycloalkane organic peroxides of the invention are safer, have fewer volatiles after the reaction, and have multiple functional groups. When the same active oxygen ratio is added, more free radicals can be provided, thereby effectively improving the degradation efficiency of polyolefins. At present, only one peroxycycloalkane, 3,6,9-triethyl-3,6,9-trimethyl-1,4,7-triperoxynonane, has been commercialized and applied in the above-mentioned fields. Therefore, it is necessary to provide new peroxycycloalkane organic peroxides with better activity. Summary of the invention

[0004] In order to provide more peroxycycloalkane organic peroxides, the present invention provides a 3,6,9,12-tetraethyl-3,6,9,12-tetramethyl-1,4,7,10-tetraperoxycyclododecane.

[0005] Another object of the present invention is to provide a method for preparing the above-mentioned peroxycycloalkanes, which can be produced continuously and has high safety.

[0006] Another object of the present invention is to provide a use of the above-mentioned peroxycycloalkane as a polyolefin degradation agent.

[0007] To achieve the above purpose, the present invention adopts the following technical solution.

[0008] A peroxycycloalkane organic peroxide, whose chemical name is 3,6,9,12-tetraethyl-3,6,9,12-tetramethyl-1,4,7,10-tetraperoxycyclododecane, referred to as TC-401, and whose chemical structure is shown in formula (I):

[0009] Formula (I).

[0010] The preparation method of the above-mentioned peroxycycloalkane organic peroxide comprises the following steps: 2-butanone and hydrogen peroxide are reacted in a microflow continuous reactor under acid catalysis, and the product is separated and purified after the reaction is completed.

[0011] The microfluidic continuous reactor is composed of a plurality of microchannel reactors as shown in CN 206474136 U connected in series through pipelines.

[0012] Preferably, the number of the microchannel reactors connected in series is 5-20, preferably 10-15.

[0013] The molar ratio of hydrogen peroxide to 2-butanone is 1-2:1, and excess hydrogen peroxide is conducive to increasing the active oxygen content of the product. The source of hydrogen peroxide is hydrogen peroxide with a mass concentration of 30%-75%. The acid is selected from sulfuric acid, acetic acid or a mixture of the two. Preferably, the volume ratio of hydrogen peroxide to acid is 100:1-100:110.

[0014] The reaction conditions are: reaction temperature of 0-95°C; reaction pressure of 0.2-2MPa; material residence time of each microchannel reactor of 0.1-10min. Preferably, the capacity of the microchannel reactor is 10-1500mL. The preferred temperature is 0-75°C, and the more preferred reaction temperature is 0-50°C.

[0015] Preferably, the separation and purification step is: standing the reaction solution and separating the layers; adding 5-10wt% sodium hydroxide, sodium carbonate or sodium bicarbonate solution to the organic layer for washing and standing for separation; removing water from the organic layer with anhydrous magnesium sulfate or anhydrous calcium sulfate to obtain a crude product, and extracting, dissolving, crystallizing, and preparing a chromatographic column to obtain a pure product. More preferably, the crude product is passed through a chromatographic column with pentane and dodecane in a volume ratio of 9:1, and the effluent component containing only the target product is retained by mass spectrometry.

[0016] An application of the above peroxycycloalkane organic peroxide in the production of plastics and rubber.

[0017] The application is preferably the above-mentioned peroxycycloalkane organic peroxide as a polymerization initiator, plastic degrading agent and rubber vulcanizing agent.

[0018] The plastics include, but are not limited to, polyethylene (PE), low-density polyethylene (LDPE), controlled rheology polypropylene (CR-PP), polyvinyl chloride (PVC), polypropylene (PP), polystyrene (PS), styrene, polytetrafluoroethylene (PTFE), polyimide, acrylonitrile-butadiene-styrene copolymer (ABS) and nylon.

[0019] The rubber includes but is not limited to silicone rubber, ethylene-propylene rubber, fluororubber, polyester-type polyurethane rubber and ethylene-vinyl acetate copolymer rubber.

[0020] The present invention has the following advantages: The peroxycycloalkane organic peroxide of the present invention has many active groups and high active oxygen content, and the reaction product does not contain volatile substances with pungent odor, which can greatly reduce the odor of the product; the flash point is low and the safety is high. The present invention adopts a microchannel reactor for continuous flow reaction, which is safe and efficient, energy-saving and consumption-reducing, high in yield, and safe in the production process. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 is the mass spectrum of the crude product of TC-401 No. 9; Figure 2 is the mass spectrum of the crude product of TC-401 No. 15; Figure 3 is the mass spectrum of the crude product of TC-401 No. 17; Figure 4 It is a schematic diagram of a microchannel reactor. DETAILED DESCRIPTION

[0022] The present invention will be further described below in conjunction with embodiments and drawings, but the present invention is not limited by the following embodiments.

[0023] Example 1 Synthesis of Compound TC-401 Five microchannel reactors in CN 206474136 U were connected in series to form a microflow continuous reactor for reaction. The proportion of reaction materials and reaction conditions are shown in Tables 1 and 2 below.

[0024] The reaction product was allowed to stand and separate; the organic layer was washed with 10wt% sodium carbonate solution and then allowed to stand and separate. The organic layer was dehydrated with anhydrous magnesium sulfate to obtain a crude product. The crude product was then passed through a chromatographic column with a volume ratio of 9:1 methanol and water. The effluent fraction containing only the target product was retained by mass spectrometry. Three batches of tests were conducted under each condition; some of the crude product was derivatized (Na + ) to obtain a mass spectrum such as Figure 1-3 As shown, the peak at about 375.2 is the proton peak of the target compound.

[0025] Referring to the method of Zhen Weixian et al. (Zhen Weixian, Rong Jun. Improvement of the iodine titration method for determining active oxygen content [J]. Thermosetting Resins, 1991, (4): 42-47), the effective oxygen content was determined by the iodine titration method. The active oxygen content of the crude product was calculated according to the following formula. The average active oxygen content of the results of three batches was calculated:

[0026] In the formula, M is the molar concentration of sodium thiosulfate solution, mol / L; V is the volume of sodium thiosulfate solution consumed in titration, mL; 16 is the atomic weight of oxygen; m is the mass of the sample, g.

[0027] From the data in the table and Figure 1-3 It can be seen that changes in reaction conditions have little effect on the types of reaction products. As the content of TC-401 in the crude product increases, the active oxygen content also increases. The active oxygen content of the crude product can be used instead of the TC-401 content (yield 90%) to explore the reaction conditions.

[0028] From the data in the table, it can be seen that the reaction temperature of compound TC-401 can be carried out under a wide range of temperature conditions from 0 to 95°C when synthesized using a microchannel reactor. However, when other conditions are the same, as the reaction temperature increases, the active oxygen content first increases and then decreases; this may be due to the fact that the reaction temperature is too high and the thermally unstable intermediates decompose, resulting in a reduction in the yield of the final product. In addition, since the product is a peroxide, an excessively high reaction temperature is likely to cause safety issues, so the reaction temperature is preferably below 75°C.

[0029] For the reaction raw materials, the molar ratio of hydrogen peroxide to 2-butanone is between 2:1 and 1:1, and the product can be obtained. Excessive hydrogen peroxide is conducive to the increase of the active oxygen content of the product. The concentration of hydrogen peroxide in hydrogen peroxide is 30%-75%. When other conditions are constant, a higher concentration of hydrogen peroxide is conducive to the formation of the product. The acid used as the catalyst can be sulfuric acid, acetic acid, or a mixture of the two. + Concentrations that are too high or too low are not conducive to the reaction. The volume ratio of hydrogen peroxide to acid can be close to 100:1 to 100:110.

[0030] In terms of reaction time, for a microchannel reactor, it is determined by the reaction pressure, the volume of the reaction plate and the number of reaction plates in series. For the same volume of reaction plates, the higher the pressure, the faster the flow rate, the shorter the residence time and the shorter the reaction time. According to the data in the table, for a reaction plate of a certain volume, the active oxygen content increases with the increase of residence time before the reaction is complete. When the reaction is at a high level, the active oxygen content does not increase much with the increase of residence time. Adjustments can be made based on time savings and the pressure resistance of the reaction container to achieve the best yield.

[0031] Use 6 blocks such as Figure 4 The control microchannel reactor shown in the figure. The microflow continuous reactor was connected in series with pipelines for reaction, and the volume of each microchannel reactor was 15mL. Three batches of synthesis were carried out according to the reaction raw material ratio and reaction conditions of condition 16, and the products were separated and purified. The average active oxygen content of the crude product was determined to be 13.23%, of which the TC-401 content was 21.13%. It can be seen that the use of Figure 4 The microchannel reactor described in has a higher yield.

[0032] Table 1 (pressure 0.2-2.0MPa, microchannel reactor volume 15mL / block)

[0033] Note: Sulfur in the table means 98 wt% sulfuric acid, vinegar means 99 wt% acetic acid, the same as in the following table.

[0034] Table 2 (pressure 0.8-1.2MPa, microchannel reactor volume 15 mL / block) .

[0035] Example 2 Application of compound TC-401 as a degradation agent The crude products obtained in Examples No. 9, 12, 15, and 17 were treated with alkanes as diluents to adjust the content to 10%; 3,6,9-triethyl-3,6,9-trimethyl-1,4,7-triperoxynonane (referred to as 301) and 2,5-dimethyl-2,5-bis(tert-butylperoxy)hexane (referred to as 101) were used as controls. Polypropylene plastic was used as the degradation raw material, and 0.3% of the degradation agent diluent of the mass of polypropylene was added. The fat solubility rate of the degraded material was measured using an XNR-400 melt fat counter, and the results are shown in the following table:

[0036] According to the data in the above table, compared with the existing products 3,6,9-triethyl-3,6,9-trimethyl-1,4,7-triperoxynonane and 2,5-dimethyl-2,5-bis(tert-butylperoxy)hexane, the product of the present invention can degrade polypropylene plastic at a lower degradation temperature and a shorter degradation time to obtain high-melting polypropylene.

[0037] The content of volatile organic matter in the degradation products of No. 12 and No. 101 was measured respectively, and the results were as follows:

[0038] It can be seen that the total amount of volatile organic compounds generated by the product of the present invention during the degradation of polypropylene is much lower than that of the control sample 2,5-dimethyl-2,5-bis(tert-butylperoxy)hexane.

Claims

1. A peroxycycloalkane organic peroxide, whose chemical name is 3,6,9,12-tetraethyl-3,6,9,12-tetramethyl-1,4,7,10-tetraperoxycyclododecane, and whose chemical structure is shown in formula (I): Formula (I).

2. The method for preparing a peroxycycloalkane organic peroxide according to claim 1, wherein: The following steps are involved: 2-butanone and hydrogen peroxide are reacted in a microflow continuous reactor under acid catalysis, and the product is separated and purified after the reaction is completed.

3. The preparation method according to claim 2, characterized in that: The microfluidic continuous reactor is composed of a plurality of microchannel reactors connected in series via pipelines.

4. The preparation method according to claim 3, characterized in that: The number of the microchannel reactors connected in series is 5-20, preferably 10-15.

5. The preparation method according to claim 3, characterized in that: The capacity of the microchannel reactor is 10-1500 mL.

6. The preparation method according to claim 2, characterized in that: The molar ratio of hydrogen peroxide to 2-butanone is 1-2:1; the source of hydrogen peroxide is hydrogen peroxide with a mass concentration of 30%-75%; The acid is selected from sulfuric acid, acetic acid or a mixture of the two; the volume ratio of hydrogen peroxide to acid is 100:1-100:110; The reaction conditions are as follows: reaction pressure is 0.2-2 MPa; reaction temperature is 0-95° C.; and material residence time in each microchannel reactor is 0.1-10 min.

7. The preparation method according to claim 2, characterized in that: The separation and purification steps are as follows: allowing the reaction solution to stand and separate; adding 5-10wt% sodium hydroxide, sodium carbonate or sodium bicarbonate solution to the organic layer for washing and then standing and separating the layers; removing water from the organic layer with anhydrous magnesium sulfate or anhydrous calcium sulfate to obtain a crude product; dissolving the crude product with a solvent and crystallizing it at a low temperature of -10 to 10°C to obtain a 95% pure product; and dissolving the crude product again and purifying it with a preparative chromatographic column to obtain a 99.5% pure product.

8. Use of the peroxycycloalkane organic peroxide as claimed in claim 1 in the production of plastics and rubber.

9. The use according to claim 8, characterized in that: The peroxycycloalkane organic peroxide is used as a polymerization initiator, a plastic degrading agent and a rubber vulcanizing agent.

10. The use according to claim 8, characterized in that: The plastic is selected from polyethylene, low-density polyethylene, controlled rheology polypropylene, polyvinyl chloride, polypropylene, polystyrene, styrene, polytetrafluoroethylene, polyimides, acrylonitrile-butadiene-styrene copolymer or nylon; The rubber is selected from silicone rubber, ethylene-propylene rubber, fluororubber, polyester-type polyurethane rubber or ethylene-vinyl acetate copolymer rubber.

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