Initially, put a, ω-tridecanedioic acid, 1,2-ethylene glycol and polymerization prevention right into the polymerization response vessel symmetrical, and start home heating at a particular home heating rate. After a, ω-tridecanedioic acid After partially dissolved, start mixing and begin the response when it reaches 180C. The water created by the response is distilled from the gas stage outlet pipe on the top of the cauldron, and afterwards compressed right into the polymerization receiving container. When the gas stage temperature drops substantially and no gas is created, the normal pressure polymerization is finished. Atmospheric pressure polymerization needs to be accomplished under nitrogen security to avoid oxygen in the air from presenting side reactions such as oxidation and fracturing. Maintain the reduced pressure for a specific amount of time, evaporate excess 1,2-ethylene glycol, and remove the gaseous items. When the acid value of the polyester is less than 1.6 KOHmg/g, the polymerization reaction ends.
Vacuum degree control in the vacuum polymerization process is an extremely important issue for the ethylene glycol tridecanedioic acid device. In this personification, vacuum purification is carried out in the vacuum system to recoup excess 1. For 2-ethylene glycol, the temperature level is managed at about 180C and the pressure has to do with 20Pa. After the healing of 1,2-ethylene glycol is completed, close the vacuum cleaner valve.
After the polymerization response is completed, include the stimulant, stir evenly, and pour the polyester right into a depolymerization reactor that has actually been increased to 230 ° C. Usage a vacuum pump to evacuate and do the depolymerization reaction under lowered stress. As the response earnings, the thickness of the material requires to remain to enhance, the heat transfer impact worsens, and the temperature requires to remain to climb. The unrefined ethylene glycol tridecanedioic acid produced by the reaction comes out of the kettle, and goes into the crude item receiving storage tank after condensation. When the gas stage temperature level drops and no item distills out, the depolymerization reaction ends.
The technique is to initial flash distillate the head portion, then rectify and accumulate the fractions under vacuum and 285 ~ 315C conditions, and finally accumulate the ended up product via flushing and dissipation. The crude product has a small amount of 1,2-ethylene glycol and lighter front portions and lighter Heavy dimers, trimers, and so on are obtained via intermittent purification to obtain the ended up item Musk-T: the residual fluid consists of dimers, trimers, and so on with larger molecular weights, which can be returned to the depolymerization pot for re-depolymerization. Hereafter process, the web content (gas chromatography) is raised from ≥ 97% to ≥ 98%, and the fragrance is reasonably pure.
In this embodiment, both basic materials of a, ω-tridecanedioic acid and 1,2-ethylene glycol are 1:1.
In this embodiment, the depolymerization catalyzer is a very energetic composite depolymerization catalyst, which is made up of aluminum carbonate and p-toluenesulfonic acid, silicotungstomolybdic acid, anhydrous copper sulfate and water in the ratio of 1.5:1:1:0.5: After dissolving in a ratio of 6, include granular silica of the same mass as the dissolved option. After complete adsorption, area it in a stove and completely dry the water at 105 ° C.