CARBONIZATION BEHAVIOR OF PETROLEUM PITCH - INSITU HIGH-TEMPERATURE C-13-NMR MEASUREMENTS

The carbonization behavior of petroleum pitch have been investigated by in situ high-temperature C-13-NMR at 390-degrees-C, The changes in the chemical structure, molecular mobility, and mesophase formation process of the pitch have been quantitatively monitored simultaneously using in situ high-temperature C-13-NMR. The initial stage of mesophase formation could be monitored at around the content level of 2%. The changes of aliphatic structure were clearly observed using NMR spectra of long-side-chain carbons and alpha-methyl carbons. The early stage of carbonization was divided into several steps and characterized. The changes in molecular mobility and in chemical structure were closely related to the mesophase transformation.