Method for preparing caprolactone from cyclohexanone by catalytic oxidation

Abstract

The invention relates to a method for preparing caprolactone through cyclohexanone catalytic oxidation. The method comprises the following steps that: raw materials, namely cyclohexanone, oxidant, solvent and catalyst, are respectively added to a reaction vessel; the reaction vessel is heated to at a temperature between 40 and 100 DEG C; constant temperature reaction is carried out for 1-15 hours; after the reaction is finished, the raw materials are cooled and separated, and then a finished product of caprolactone can be obtained, wherein the catalyst contains 50-100 percent of zinc oxide and 50-0 percent of other metallic oxide in weight percentage; the solvent is nitrile; the oxidant is hydrogen peroxide or peracetic acid. High caprolactone yield and selectivity can be obtained by adopting the method provided by the invention; meanwhile, the catalyst used in the method is low in price, easy to get and simple to prepare, contains no halogen element, has high stability, and can be used repeatedly.

Description

Technical field

[0001] The invention relates to the field of industrial catalysis in the petrochemical industry, in particular to a method for preparing caprolactone by catalytic oxidation of cyclohexanone.

Background technique

[0002] ε-caprolactone is an important organic synthesis intermediate, mainly used for the synthesis of polycaprolactone and copolymerization or blending modification with other esters; ε-caprolactone can also be used as a strong solvent to dissolve many Polymer resin, which has good solubility for some insoluble resins, such as it can dissolve chlorinated polyolefin resin and "ESTANE" polyurethane resin. Among them, polycaprolactone (PCL) is a linear aliphatic polyester obtained by ring-opening polymerization of ε-caprolactone (ε-CL).

[0003] The synthesis of ε-caprolactone has difficulties in raw material quality, production safety and product stability, etc., so its synthesis technology is very difficult. At present, only a few companies in ...

Examples

Embodiment 1

[0018] Add successively 1.0 grams of cyclohexanone, 1.2 grams of 30wt% hydrogen peroxide, 10 milliliters of acetonitrile and 1.0 grams of catalyst (zinc oxide) in a stainless steel reaction kettle lined with polytetrafluoroethylene in 30 milliliters of liners, and the reaction kettle is sealed. Heat to 100°C, and react at a constant temperature of 100°C for 1 hour, and take samples for analysis after the material is cooled to room temperature. The reaction result is: the conversion rate of cyclohexanone is 75.7%, and the selectivity of caprolactone is 100%. In addition, the activity and selectivity of the catalyst did not decrease after 6 repeated cycles.

Embodiment 2

[0020] Add 1.0 grams of cyclohexanone, 4.0 grams of 30wt% hydrogen peroxide, 6 milliliters of acetonitrile and 0.5 grams of catalyst (90wt% zinc oxide+10wt% aluminum oxide) successively in a 30 milliliter stainless steel reactor lined with polytetrafluoroethylene, and seal Reactor, heat the reactor to 80°C, and react at a constant temperature of 80°C for 6 hours, and take samples for analysis after the material is cooled to room temperature. The reaction result is: the conversion rate of cyclohexanone is 89.7%, and the selectivity of caprolactone is 100%. In addition, the activity and selectivity of the catalyst did not decrease after 4 repeated cycles.

Embodiment 3

[0022] Add 1.0 grams of cyclohexanone, 6.0 grams of 30wt% hydrogen peroxide, 15 milliliters of acetonitrile and 0.5 grams of catalyst (80wt% zinc oxide+20wt% lanthanum oxide) successively in a 30 milliliter stainless steel reactor lined with polytetrafluoroethylene, and seal Reactor, the reactor was heated to 40°C, and reacted at a constant temperature of 40°C for 15 hours, and samples were taken for analysis after the material was cooled to room temperature. The reaction result is: the conversion rate of cyclohexanone is 72.3%, and the selectivity of caprolactone is 100%. In addition, the activity and selectivity of the catalyst did not decrease after 4 repeated cycles.

Technical field

[0001] The invention relates to the field of industrial catalysis in the petrochemical industry, in particular to a method for preparing caprolactone by catalytic oxidation of cyclohexanone.

Background technique

[0002] ε-caprolactone is an important organic synthesis intermediate, mainly used for the synthesis of polycaprolactone and copolymerization or blending modification with other esters; ε-caprolactone can also be used as a strong solvent to dissolve many Polymer resin, which has good solubility for some insoluble resins, such as it can dissolve chlorinated polyolefin resin and "ESTANE" polyurethane resin. Among them, polycaprolactone (PCL) is a linear aliphatic polyester obtained by ring-opening polymerization of ε-caprolactone (ε-CL).

[0003] The synthesis of ε-caprolactone has difficulties in raw material quality, production safety and product stability, etc., so its synthesis technology is very difficult. At present, only a few companies in ...

Examples

Embodiment 1

[0018] Add successively 1.0 grams of cyclohexanone, 1.2 grams of 30wt% hydrogen peroxide, 10 milliliters of acetonitrile and 1.0 grams of catalyst (zinc oxide) in a stainless steel reaction kettle lined with polytetrafluoroethylene in 30 milliliters of liners, and the reaction kettle is sealed. Heat to 100°C, and react at a constant temperature of 100°C for 1 hour, and take samples for analysis after the material is cooled to room temperature. The reaction result is: the conversion rate of cyclohexanone is 75.7%, and the selectivity of caprolactone is 100%. In addition, the activity and selectivity of the catalyst did not decrease after 6 repeated cycles.

Embodiment 2

[0020] Add 1.0 grams of cyclohexanone, 4.0 grams of 30wt% hydrogen peroxide, 6 milliliters of acetonitrile and 0.5 grams of catalyst (90wt% zinc oxide+10wt% aluminum oxide) successively in a 30 milliliter stainless steel reactor lined with polytetrafluoroethylene, and seal Reactor, heat the reactor to 80°C, and react at a constant temperature of 80°C for 6 hours, and take samples for analysis after the material is cooled to room temperature. The reaction result is: the conversion rate of cyclohexanone is 89.7%, and the selectivity of caprolactone is 100%. In addition, the activity and selectivity of the catalyst did not decrease after 4 repeated cycles.

Embodiment 3

[0022] Add 1.0 grams of cyclohexanone, 6.0 grams of 30wt% hydrogen peroxide, 15 milliliters of acetonitrile and 0.5 grams of catalyst (80wt% zinc oxide+20wt% lanthanum oxide) successively in a 30 milliliter stainless steel reactor lined with polytetrafluoroethylene, and seal Reactor, the reactor was heated to 40°C, and reacted at a constant temperature of 40°C for 15 hours, and samples were taken for analysis after the material was cooled to room temperature. The reaction result is: the conversion rate of cyclohexanone is 72.3%, and the selectivity of caprolactone is 100%. In addition, the activity and selectivity of the catalyst did not decrease after 4 repeated cycles.