Investigation of the Stability of Quaternary Ammonium Methyl Carbonates

• Published in: Journal of surfactants and detergents 2012-03, Vol.15 (2), p.199-205
• Main Authors: Weisshaar, Duane E., Earl, Gary W., Amolins, Michael W., Mickalowski, Kyle L., Norberg, Justin G., Rekken, Brian D., Burgess, Angela M., Kaemingk, Bethany D., Behrens, Katherine C.
• Format: Article
• Language: English
• Subjects: Amines; Ammonia; Ammonium; Anions; Aquatic Pollution; Aqueous stability; Carbonates; Chemistry; Chemistry and Materials Science; Dimethyl carbonate; Green synthesis; Industrial Chemistry/Chemical Engineering; Ions; Methyl carbonate; NMR; Nuclear magnetic resonance; Original Article; Physical Chemistry; Polymer Sciences; Quaternary ammonium; Surfaces and Interfaces; Surfactant; Thermal decomposition; Thermal stability; Thin Films; Waste Water Technology; Water Management; Water Pollution Control
• ISSN: 1097-3958; 1558-9293
• DOI: 10.1007/s11743-011-1292-1

Quaternary ammonium compounds are used commercially for a variety of applications and some are of interest as ionic liquids. For many years dimethyl carbonate has been touted as a green reagent, including its use for methylation (quaternization) of tertiary amines. In addition, substitution of the methyl carbonate by other anions can be efficiently and cleanly accomplished by reaction with the corresponding acid. How stable are these methyl carbonate quaternary compounds? High field 13 C NMR shows that in the presence of water, the methyl carbonate is converted to bicarbonate. Headspace GCMS indicates that the alkylammonium methyl carbonate salts are stable below 170–180 °C while the bicarbonate salts are stable to only about 140 °C. Thermal decomposition occurs by decarboxylation and by dealkylation.