Submitted to: Journal of the American Oil Chemists' Society
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 1/17/2008
Publication Date: 2/7/2008
Citation: Kenar, J.A., Knothe, G.H. 2008. 1,2-isopropylidene glycerol carbonate: preparation, characterization, and hydrolysis. Journal of the American Oil Chemists' Society. 85(4):365-372.
Interpretive Summary: In the interest of expanding the use of bio-based compounds prepared from renewable resources to replace petroleum based products, and to help utilize excess glycerin supplies generated from the burgeoning biodiesel industry, the preparation, characterization and chemistry of novel glycerol-based compounds was investigated. This work provides fundamental information about the preparation and reactivity of these glycerol compounds that contain a carbonate moiety which is not currently available. The basic knowledge gained from this research has clear importance for the potential utilization of the compounds studied. The development of new industrial products derived from renewable resource, not only benefits farmers in the United States, but also reduces our dependence on petroleum-based resources.
Technical Abstract: The utilization of excess glycerol supplies derived from the burgeoning biodiesel industry is of major importance to the oleochemical industry as the economic viability of the biodiesel and oleochemical industries are closely linked to glycerol prices. Carbonate compounds based on glycerol, such as glycerol carbonate, are gaining prominence due to its simple preparation, interesting properties and chemistry. Herein, the synthesis, physical properties, and chemistry of an interesting glycerol-based carbonate (4, bis[(2,2-dimethyl-1,3-dioxolan-4-yl)methyl] carbonate) is reported. Carbonate interchange reaction between solketal (isopropylidene glycerol) and diethyl carbonate in the presence of sodium methoxide catalyst gave solketal carbonate, 4, in 65-70% isolated yields. Carbonate 4 was characterized using Fourier transform infrared spectroscopy (FTIR), 1H and 13C nuclear magnetic resonance spectroscopy (NMR), and gas chromatography-mass spectrometry (GC/MS). The kinematic viscosity at 40 deg C, refractive index, and melting point of 4 were determined to be 26.7 mm²/s, n 1.4460, and -50 deg C, respectively. The lubricity of neat solketal carbonate was examined using a high frequency reciprocating rig (HFRR) testing apparatus and shown to have lubricity properties similar to fatty acid esters. Hydrolysis of carbonate 4’s isopropylidene groups gave polyol 6, bis(2,3-dihydroxypropyl) carbonate in good yields (84%). Carbonate polyol 6 was characterized by 1H and 13C NMR and represents a potentially novel polyol component that may be useful in the syntheses of interesting carbonate containing esters and polymers.