Technical Paper
Average Molecular Structure of Gasoline Engine Combustion Chamber Deposits Obtained by Solid-State 13C, 31P, and 1H Nuclear Magnetic Resonance Spectroscopy
1993-10-01
932811
Combustion chamber deposits (CCDs) have been the subject of much research aimed at understanding their role in driveabilty and emissions performance in SI engines. Correlations have been drawn between CCDs and octane requirement increase (ORI). In order to gain a better understanding of the complex structural chemistry of these carbonaceous deposits a large number of these deposits, generated in several SI engines, have been investigated by solid-state 13C nuclear magnetic resonance (NMR) spectroscopy. 13C NMR methodologies developed for the study of coal were used to obtain structural and molecular parameters for each of the deposits. These parameters provide an “average molecule” description which defines the average building block of the polymeric backbone of CCDs.
