623-96-1Relevant articles and documents
Synthesis of dipropyl carbonate over calcined hydrotalcite-like compounds containing la
Ma, Qingxiang,Zhao, Tiansheng,Wang, Ding,Niu, Wenqi,Lv, Peng,Tsubaki, Noritatsu
, p. 142 - 148 (2013)
Dipropyl carbonate (DPC) was selectively synthesized via transesterification of dimethyl carbonate (DMC) and n-propanol over Mg-Al composite oxide containing La catalysts. The catalysts were prepared by calcining the precursors of hydrotalcite-like compounds (HTLcs) from co-precipitation method. The effect of La content (nMg:n Al:nLa = 3:1:x) in the catalyst on the synthesis of DPC was investigated. And the catalyst exhibited the highest catalytic activity when x was tuned to 0.7. Under the optimized reaction conditions, the DMC conversion and DPC selectivity were 98.4% and 95.4%, respectively. These catalysts were characterized by thermogravimetry differential thermal analysis (TG-DTA), X-ray diffraction (XRD), nitrogen adsorption-desorption, Fourier transform infrared (FT-IR), temperature programmed desorption with CO2 (CO 2-TPD) and scanning electron micrograph (SEM). It was clarified that the amount of basic sites of moderate strength, formed by chelating bidentate carbonate, was enhanced with the La content increasing until x = 0.7, which were the catalytically-active sites for this reaction. But when La content x reached 1.0, these sites were transformed to bridging bidentate carbonate, leading to a loss of the catalytic activity to some extent. These findings indicated that La content controlled the catalytic performance of the composite oxides catalysts via structure change of the basic sites. The catalyst was easily prepared and handled, easily separated from the reaction medium and could be reused many cycles.
Boosting the methanolysis of polycarbonate by the synergy between ultrasound irradiation and task specific ionic liquids
D'Anna, Francesca,Sbacchi, Maria,Infurna, Giulia,Dintcheva, Nadka Tz.,Marullo, Salvatore
supporting information, p. 9957 - 9967 (2021/12/24)
In an attempt to perform polycarbonate chemical recycling in a more sustainable way, we took into consideration the combined use of ultrasound irradiation and task specific ionic liquids. Towards this aim, the methanolysis of polycarbonate, into dimethylcarbonate and bisphenol A, was carried out in the presence of cholinium-based ionic liquids featuring anions derived from amino acids and other eco-friendly species. The target process was optimized in terms of both energy and material amounts as well as in terms of the nature of the catalysts used. The proposed protocol allowed high conversion and yields of bisphenol A to be obtained, under milder conditions compared to the ones so far reported in the literature, perfectly fulfilling green chemistry principles. The best performing catalyst can be reused without significant loss in performance and the methodology can be successfully applied to post-consumer polycarbonate samples. This journal is
Room temperature and normal pressure preparation method of organic carbonate
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Paragraph 0082-0084, (2020/07/15)
The invention relates to the technical field of organic synthesis, and provides a room temperature and normal pressure preparation method of organic carbonate. The method comprises the following steps: introducing carbon dioxide into an imidazole ionic liquid to obtain a mixture; mixing the obtained mixture with alcohol and halogenated hydrocarbon, and carrying out addition-substitution reactionsto obtain organic carbonate. The whole reaction process is carried out at a room temperature under a normal pressure. The activation energy of the reaction is reduced by using imidazole ionic liquid and halogenated hydrocarbon, and finally, organic carbonate is prepared from CO2 at a room temperature under a normal pressure.
