Phenol ketone products

Plastic rubber

Current Location： Home > News > Chemical Knowledge > The production process and preparation method of dioctyl ester doa.

[Chemical Knowledge]：The production process and preparation method of dioctyl ester doa.

Read： 609 Time：18months ago Source：Transform the World with Simplicity

Dioctyl adipate (DOA) is a commonly used high temperature, double low degradation plasticizer, widely used, such as PVC, polychloroprene rubber, acrylonitrile-butadiene-styrene copolymer, polyurethane and other polymers in the production process, DOA is widely used. In this paper, the production process and preparation method of DOA will be described in detail.

1. production process
The production process of
DOA can be divided into two steps: synthesis of dioctyl diethyladipate (DADA) and hydrocracking.

1. Synthesis of DADA

Synthesis of DADA is roughly divided into the following steps:

(1) Drying: Diethylhexanoic acid and n-octanol are heated to 90-110 ° C. to dehydrate them to obtain anhydrous diethanoic acid.

(2) Esterification: Anhydrous diethylhexanoic acid and n-octanol are added into an esterification reactor according to a certain proportion, inert gas is introduced, and the reaction is heated to about 170 ° C., and the reaction is carried out for 4-5 hours to obtain DADA.

(3) Distillation under reduced pressure: The reaction batch was heated to about 220 ° C. in the atmosphere and distilled under reduced pressure to obtain DADA.

2. Hydrocracking

DADA and a certain amount of catalyst are added into a reactor for hydrocracking. The hydrocracking reaction is carried out at a temperature of 400-450°C and a pressure of 2-4MPa, and DOA can be obtained in about 4 hours.

2. preparation methods

DOA preparation methods mainly include solution method, batch method and continuous method.

1. Solution Method

DADA is dissolved in n-octanol, a catalyst is added, the reaction solution is heated to about 200 ° C. for hydrogenation, and after the reaction is completed, distillation is performed under reduced pressure to obtain DOA.

2, batch method

DADA and n-octanol are mixed according to a certain proportion, the catalyst is added, the reaction kettle is heated to 350-400 degrees C, reaction 2-3 hours, and then reduced pressure distillation, that is, the preparation of DOA.

3, continuous method

DADA, n-octanol and catalyst are mixed in a certain proportion, sent to the hydrogenation reactor for continuous catalytic hydrogenation, after the reaction through the decompression kettle for decompression distillation, the production of DOA.

Among them, the batch method is the traditional DOA preparation method, but there are problems such as low reaction efficiency, small yield and complex process. Solution method and continuous method are new technologies developed in recent years, which have the advantages of high reaction efficiency, large yield and simple process compared with batch method. Summary of

3.

DOA is a widely used plasticizer, and its production process and preparation method are of great significance to polymer production. At present, the solution method and continuous method are the trend of DOA preparation, which will be more widely used in the future.