Propylene carbonate, physical properties

The physical properties of finish removers vary considerably due to the diverse uses and requirements of the removers. Finish removers can be grouped by the principal ingredient of the formula, method of appHcation, method of removal, chemical base, viscosity, or hazardous classification. Except for method of apphcation, a paint remover formulation usually has one aspect of each group, by which it can be used for one or more appHcations. A Hst of the most common organic solvents used in finish removers has been compiled (3). Many are mentioned throughout this article others include ethyl lactate [97-64-3] propylene carbonate [108-32-7] furfural alcohol [98-01-1/, dimethyl formamide [68-12-2] tetrahydrofuran [109-99-9] methyl amyl ketone [110-43-0] dipropylene glycol methyl ether [34590-94-8] and Exxate 600, a trade name of Exxon Chemicals. 

Some physical properties of 3-propyl-4-ethylsydnone have been determined at various temperatures <1997BCJ315>. The dielectric constant (e = 64.6 at 25°C) is high compared to many organic solvents and close to that of propylene carbonate (e = 64.9), a typical nonaqueous polar solvent. 

Although two cations are often observed to complex in a dinuclear fashion in the axial macrobicycles, as noted in the previous paragraphs, lateral macrobicycles (Figure 1) are clearly designed for incorporation of two metal ions.9,171,172 These two metal ions are by construction necessarily in chemically different environments, which can greatly affect both chemical and physical properties. For example, in the bis-copper(II) complex of (49b) the two copper ions exhibit greatly different redox potentials (+ 550 and + 70 mV vs. NHE in propylene carbonate).9... 

Although a number of solvents have been used by different workers, only a few enjoy continued favor. In Table 7.11 the physical properties of more than 50 solvents are listed (not all of them are aptotic). In the following paragraphs some of the properties and purification methods for four solvents are discussed acetonitrile, propylene carbonate (PC), dimethylformamide (DMF), and dimethyl sulfoxide (Me2SO). These are the most widely used solvents and prob-... 

HP he study of the behavior of electrolytes in mixed solvents is currently arousing considerable interest because of its practical and fundamental implications (1). Among the simpler binary solvent mixtures, those where water is one component are obviously of primary importance. We have recently compared the effects of small quantities of water on the thermodynamic properties of selected 1 1 electrolytes in sulfolane, acetonitrile, propylene carbonate, and dimethylsulfoxide (DMSO). These four compounds belong to the dipolar aprotic (DPA) class of solvents that has received a great deal of attention (2) because of their wide use as media for physical separations and chemical and electrochemical reactions. We interpreted our vapor pressure, calorimetry, and NMR results in terms of preferential solvation of small cations and anions by water and obtained... 

Figure 45 shows another example of the dependence of polymer physical properties on the branch length. Copolymers were made with Cr/silica catalyst to have the same approximate density and MI. Various comonomers were used, ranging from propylene to 1-octene. The ESCR of each polymer was then determined and is plotted against the number of carbon atoms in the comonomer. There is a clear advantage associated with longer branch lengths. 

Among the most commonly utilized synthetic polymers are polyolefins, such as polyethylenes (PEs), polypropylenes (PPs), and ethylene-propylene copolymers (P(E-co-P)s). Despite their simple elemental compositions, consisting of only carbon and hydrogen, it is well known that their physical properties are quite dependent on the microstructural features, such as short- and long-chain branchings, stereoregularities, chemical inversions of monomer enchainment, sequence distributions, etc. ... 

Ethylene carbonate (EC) and propylene carbonate (PC) have favorable physical and electrochemical properties such as high relative permittivity, high donicity, and relatively wide potential window. The direct fluorination of EC was successfully carried out to provide 4-fluoro-l,3-dioxolan-2-one (fluoroethylene carbonate, FEC) as shown in Scheme 2.3 [20], The fluorination of EC was strongly dependent on a choice of a reaction medium and no solvent was preferred from the viewpoint of conversion. FEC was further fluorinated to give three di-fluorinated derivatives. On the other hand, FEC was also prepared from 4-chloroethylene carbonate by exchange with KF [21], FEC was tested as an electrolyte additive for rechargeable lithium cells [21, 22] and is now practically used [23, 24],... 

It may seem surprising that polymers composed only of carbon and hydrogen atoms can be so fiexible, but the versatility of polyolefins can be easily explained by the way the monomer molecules - ethylene, propylene, and higher a-olefins -are connected to form the polymer chains. It is true for any polymer, but dramatically so for polyolefins, that chain micro structure is the key to understanding their physical properties. 

Aprotic electrolytes based upon methyl formate, propylene carbonate and dimethyl formamide as solvents and lithium chloride plus aluminum chloride, lithium hexafluoroarsenate and lithium perchlorate as solutes are discussed. The effect of additives, other aprotic solvents, other salts and trace amounts of water on species in solution and other physical properties are described. 

Li X H, Tjong S C, Meng Y Z, Zhu Q, Fabrication and properties of poly(propylene carbonate)/calcium carbonate composites , Journal of Polymer Science Part B Polymer Physics, 2003 41 1806-1813. 

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