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

The carbonization behavior of petroleum pitch have been investigated b y in situ high-temperature C-13-NMR at 390-degrees-C, The changes in t he chemical structure, molecular mobility, and mesophase formation pro cess of the pitch have been quantitatively monitored simultaneously us ing in situ high-temperature C-13-NMR. The initial stage of mesophase formation could be monitored at around the content level of 2%. The ch anges of aliphatic structure were clearly observed using NMR spectra o f long-side-chain carbons and alpha-methyl carbons. The early stage of carbonization was divided into several steps and characterized. The c hanges in molecular mobility and in chemical structure were closely re lated to the mesophase transformation.