Carbonization properties of partially hydrogenated aromatic compounds-II. Factors influencing the coke yield in the carbonization of hydrogenated pyrene

Factors influencing the coke yield in the carbonization of hydrogenated pyrenes were investigated from the view of reactivities of their hydrogens. The amount of hydrogen located at 4 ppm in their proton NMR spectrum was found to be intimately related to the coke yield of hydrogenated pyrenes. Oxidative pretreatment at 150°C significantly increased the coke yield. The structural changes of hydrogenated pyrenes by oxidative pretreatment were investigated by means of GPC, IR and NMR. The scheme of oligomerization as the first step of carbonization is discussed in connection with the reactivities of hydrogens in hydrogenated pyrenes.