Blending of Mesophase Pitches to Enhance Their Stabilization Reactivi

Abstract

A mesophase pitch of low stabilization reactivity because of highly condensed structure was blended to enhance the stabilization reactivity with some mesophase pitches of higher reactivity which carry more amount of naphthenic and methyl groups. The blending of the latter pitches in 30-50% improved the spinning properties and shortened the time required for the stabilization. The rate of oxygen up-take in the stabilization of the blended pitch was same to the average one of two component pitches, however, the amount necessary for the complete stabilization was smaller than the averaged one.The pitches were dissolved well each other without significant reactions between them to reduce the viscosity of fused pitch. The blended pitches appeared to be oxidized independently to up-take oxygen, however, the sufficient stabilization of the pitch of lower reactivity was achieved when the partner of higher reactivity was enough stabilized. The mesogen molecules in the more reactive mesophase pitch which is stabilized earlier may inhibit softening of the whole blended mesophase pitch including not-sufficient stabilized mesogens in the less reactive mesophase pitch. Significant amount of additives is necessary in such a mechanism of the stabilization enhancement because the mesogens of lower reactivity should be surrounded by those of higher reactivity.