Characterization of Asphalt Fractions by NMR Spectroscopy

Abstract

Petroleum asphalt was separated into saturates, naphthalene aromatics, polar aromatics, and asphaltenes using the Corbett method. These asphalt fractions were characterized by H-1 and C-13 nuclear magnetic resonance spectroscopy (NMR). The spectra of saturates illustrate only traceable quantities of aromatic hydrogen and aromatic carbon. Naphthalene aromatics, polar aromatics, and asphaltenes all have broad bands in the aromatic regions of both H-1 and C-13 NMR spectra. These broad bands demonstrate the presence of polycondensed aromatic rings present in the structure of naphthalene aromatics, polar aromatics, and asphaltenes. Based on available literature, numerous NMR resonance bands are identified. The quantitative estimations for various kinds of protons and carbons in the asphalt fractions are compared.