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Green Catalysis, Green Chemistry, and Organic Syntheses for Sustainable Development
Published in Miguel A. Esteso, Ana Cristina Faria Ribeiro, A. K. Haghi, Chemistry and Chemical Engineering for Sustainable Development, 2020
Divya Mathew, Benny Thomas, K. S. Devaky
Organic carbonates represent esters of carbonic acids and are a class of compounds with a broad field of application due to their unusual properties. They are easily available in large amounts, inexpensive; possess low toxicity; and are completely biodegradable. Organic carbonates are widely accepted for extraction purposes, pharmaceutical, and medical applications. Moreover, they are extensively exploited in batteries too. Two subclasses of carbonates are differentiated: open chain and cyclic organic carbonates.15 Cyclic carbonates display a wider temperature range in the liquid state, and therefore, they are more suitable as solvents. Exclusively, such cyclic carbonates fulfill the necessities of green solvents such as low flammability, volatility, and low toxicity.16 Propylene carbonate is an aprotic, highly dipolar solvent with low viscosity and a very large liquid state range. Since propylene carbonate has a high molecular dipole moment of 4.9 D, it is susceptible to microwave irradiation. It can be considered as a very interesting solvent for microwave-assisted organic synthesis; however, unfortunately, it has been hardly investigated yet. Furthermore, if the pure enantiomeric carbonate is utilized, its stereogenic center can be exploited for the enantioselectivity of a stereoselective reaction.
2 into Industrial Products
Published in Ashok Kumar, Swati Sharma, 2 Utilization, 2020
Ramya Thangamani, Lakshmanaperumal Vidhya, Sunita Varjani
In the 1950s, various stakeholders strategized their business unions to produce cyclic carbonates from carbon dioxide. To be specific, when the carbon dioxide is treated with propylene oxide or ethylene in the presence of essential impetus, it produces propylene carbonate or ethylene carbonate, respectively. Chemicals such as styrene oxide, cyclohexene oxide, and 1,3-propylene oxide can also be utilized along with carbon dioxide in the production of cyclic carbonates, while the produce will be only less in volume. In 2010, the carbon dioxide was considered as a base and was used to produce 80,000 tons of cyclic carbonates (Alper and Yuksel-Orhan, 2017). The carbon dioxide is also used as a feedstock to amalgamate the aliphatic and fragrant polycarbonates. In Asahi Kasei process, the yearly production of polycarbonate is 600,000 tons, which is used as a feedstock in addition to carbon dioxide, bisphenol, and ethylene oxide (Fukuoka et al. 2007). According to Langanke et al. (2014), Covestro constructed a plant to copolymerize the carbon dioxide and propylene oxide in order to yield polymeric polyols (i.e. polyether carbonates), which are commercially called as cardyon. Having been found in froth beddings, these polyols can be used in the production of polyurethanes. The alkali generation produces the carbon dioxide. Approximately 5,000 tons of polymeric polyols is manufactured from this plant every year.
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Published in Joseph C. Salamone, Polymeric Materials Encyclopedia, 2020
Anionic and coordination polymerizations of cyclic aliphatic carbonates with a six-membered ring at moderate temperatures can yield pure, high molecular weight polycarbonates. In contrast, cationic polymerizations result in low-molecular-weight polycarbonates containing a few percent of ether linkages. Five-membered cyclic aliphatic carbonates like ethylene carbonate and propylene carbonate hardly undergo a ring opening. The polymerization of such alkylene 1,2- carbonates has been reported to proceed in the presence of metal alkoxides, metal acetylacetonates, and metal alkyls by partial elimination of carbon dioxide, yielding the respective low molecular weight poly(alkylene ether carbonate)s only at high temperature. Copolymerization of propylene oxide or other epoxide and carbon dioxide in the presence of organozic-based catalysts is generally accompanied by the formation of the cyclic five-membered carbonate, propylene carbonate, or other alkylene carbonate.
Study of catalyst performance of two inorganic/organic and inorganic/inorganic hybrid catalysts on the CO2 cycloaddition to propylene oxide: kinetics and thermodynamics
Published in Chemical Engineering Communications, 2022
Heriberto Díaz Velázquez, A. Rodríguez-Hernández, E. Meneses-Ruiz, J. A. Muñoz-Arroyo
The characterization and analytical determination of the reactants and product composition allowed us to establish the path of the cycloaddition reaction to form propylene carbonate from Carbon Dioxide (CO2) and Propylene Oxide (PO). The reaction path can be represented as follows (Gaffney and Marley 2018a):