Characterization of coal tar pitches with different softening points by 1H NMR: Role of the different kinds of protons in the thermal process

Abstract Optimum experimental conditions for a quantitative 1 H Nuclear Magnetic Resonance ( 1 H NMR) analysis of coal tar pitches are given. From the variety of sample concentrations studied, it was found that 3% in weight was the most suitable concentration for 1 H NMR experiments. The cut-off points were adjusted and the different types of hydrogen in the resultant regions were identified. The patterns used for both purposes were prepared according to the quali- and quantitative information given by Gas Chromatography (gc). Using these conditions, four coal tar pitches with different softening point were characterized. Some new parameters were defined with the aim of obtaining an important amount of more reliable information.