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The Study & Development Of High Level Pigment Intermediate-DMSS

Posted on:2006-04-11Degree:MasterType:Thesis
Country:ChinaCandidate:H R TianFull Text:PDF
GTID:2121360185478521Subject:Engineering
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Dimethyl 1,4-cyclohexanedione-2,5-dicarboxylate (DMSS) is an important intermediate for Quinairdone pigment, 1,4-cyclohexdianone and photosensitive polymer. In the present dissertation, a series of high-quality DMSS have been synthesized using succinic acid from the low level outcome of petroleum as an initial material and macromolecule resin as catalyst. The processes included esterification, Dieckmann reaction, neutralization and physical separating methods. The obtained products exhibit the same quality lever as European top manufacturer (e.g. DSM Corporation in Holland).The esterification reaction was performed with succinic acid and excess methanol in the present of macromolecule resin, yielded dimethyl succinate (DMS) with a purity over 99.8 %. Significantlly, the macromolecule resin catalyzer could be recycle endlessly. The excess methanol and the remaining methyl succinate ( Monoester ) could be circulated in next esterifying reaction. There are not waste residue in this route. It won't cause pollution.Dieckmann reaction was carried out between excess DMS and sodium methylate. A mixture of dimethyl 1,4-cyclohexanedione-2,5-dicarboxylate sodium salt (sodium salt of DMSS) and DMS were obtained. Subsequently, a high-pressure thin-film separator was used to separate above mixture. DMS could be circulated in the process. The salt of DMSS was neutralized by sulfuric acid, separated by centrifugal machine, and then a purified DMSS solid was obtained with purity over 99.5%. The appearance of DMSS shows milk-yellow to white color. The consume amount of main material was 1.8 tons of succinic acid per ton of DMSS. The theoretic consume is 1.034 t/t, and normal literature reported was over 2.4 t/t. In this modified process, harmful organic solvents such as xylene, dimethyl sulfoxide were not employed, indicated that the novel route is of friendly-environment.
Keywords/Search Tags:Dimethyl 1,4-cyclohexanedione-2,5-dicarboxylate, Succinic acid, Polymeric resin, Esterification, Thin-film separate
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