First put a, ω-tridecanedioic acid, 1,2-ethylene glycol and polymerization inhibitor into the polymerization response container symmetrical, start to heat up at a specific home heating rate, as well as wait on a, ω-tridecanedioic acid Beginning stirring after partial dissolution, and begin the reaction when it reaches 180C. The water generated by the response is distilled from the gas stage electrical outlet pipeline at the top of the storage tank, as well as enters the polymerization receiving tank after condensation. When the temperature of the gas phase drops considerably and no gas is produced, the normal stress polymerization is completed. Air pressure polymerization needs to be performed under the protection of nitrogen to stay clear of side reactions such as oxidation as well as splitting presented by oxygen airborne. Maintain the minimized stress for a certain amount of time to boil down off the excess 1,2-ethylene glycol as well as discharge the gas items. When the polyester acid worth is lower than 1.6 KOHmg/g, the polymerization response ends.
Vacuum control in the vacuum polymerization procedure is an incredibly important concern for the ethylene tridecanedibasic acid plant. In this personification, vacuum distillation is performed in the vacuum system to recover excess 1, 2-Ethylene glycol, currently, the temperature level is managed at about 180C, as well as the stress is about 20Pa. After the recuperation of 1,2-ethylene glycol is completed, shut the vacuum cleaner shutoff.
After the polymerization response mores than, include the catalyst, stir evenly, put the polyester into the depolymerization reactor that has actually been elevated to 230 ° C, make use of an air pump to leave, and also carry out the depolymerization reaction under minimized pressure. As the response proceeds, the thickness of the product requires to increase constantly, the heat transfer result comes to be inadequate, as well as the temperature needs to be continuously raised. The unrefined ethylene tridecanedibasic acid generated by the response is separated from the kettle, and also enters the unrefined item receiving tank after condensation. When the gas stage temperature level declines as well as no item is distilled out, the depolymerization response finishes.
Flash distillation is made use of very first to boil down the head portion, and then remedy and also gather fractions under vacuum at 285 ~ 315 ° C, and also lastly collect the finished product by flushing. The crude item consists of a percentage of 1,2-ethylene glycol as well as lighter front fractions as well as lighter fractions. Heavy dimers, trimers, etc, are obtained through set purification to acquire the completed musk-T: the raffinate contains dimers, trimers, etc with bigger molecular weights, and can be gone back to the depolymerization pot for re-depolymerization. Hereafter procedure, the material (gas chromatography) is raised from ≥ 97% to ≥ 98%, and also the scent is fairly pure.
In this example, both resources of a, ω-tridecanedioic acid and 1,2-ethylene glycol are 1:1.
In this embodiment, the depolymerization catalyst is a very energetic composite depolymerization driver, which is composed of aluminum carbonate, p-toluenesulfonic acid, silicotungstic molybdenum acid, anhydrous copper sulfate as well as water according to the ratio of 1.5:1:1:0.5: After the proportion of 6 is liquified, add granular silica of the same quality as the dissolved option, after complete adsorption, place it in an oven, and also dry the water at 105 ° C.