Submitted to: Journal of the American Oil Chemists' Society
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 10/21/2016
Publication Date: N/A
Interpretive Summary: Finding new uses for glycerol, the by-product of biodiesel production, has been the focus of many research projects since biodiesel production started to increase over 15 years ago. Before production of biodiesel was increased for alternative fuel uses, the glycerol market was saturated. For several years, many researchers have been making small molecules and polymers from glycerol. While the polymers, such as polyesters, dissolve in polar organic solvents, such as methanol, they are not soluble in water. However, when glycerol is reacted with iminodiacetic acid, a water-soluble polyester is produced. Such molecules are important because they could be used as a model compounds to facilitate the production of more water soluble polyesters and such molecules would allow scientists to create polyesters with tunable water solubility that can be used in drug delivery and a variety of temperature sensitive applications within the body and throughout the manufacturing industry. Finding new ways to use glycerol would add value to it that could be used to off-set the production costs of biodiesel. This would consequently lower the consumer price of biodiesel at commercial outlets allowing American families to more readily purchase biofuels at competitive rates to petroleum fuels.
Technical Abstract: Esterifications between iminodiacetic acid and its methyl and ethyl derivatives with glycerol or solketal have been studied. The synthesis of IDA with solketal was unsuccessful under experimental conditions of 70 degrees C and 200 torr for 24h. However, using dimethyl iminodiacetic acid with solketal produced the desired di-substituted ester in yields as high as 96.4 percent. While keeping all other reaction conditions the same, the di-substituted product could be produced at ambient pressure. However, the conversion was typically low (approximately 25 percent). Changing the monomer from dimethyl iminodiacetic acid to diethyl iminodiacetic acid reduced the yield to approximately 80 percent. In order to deprotect the solketal unit to give the 1,2-diol, the nitrogen in the iminodiacetic acid unit had to first be protected with 1-trifluoroacetyl imidazole.