Influences of internal stress arising during carbonization of polycarbodiimide: Part II. Development of inhomogeneous microtexture and fragmentation of the carbon/carbon composite film Original Research Article

Carbon/carbon composite films were prepared by using polycarbodiimide (PCDI) as a starting matrix and the inhomogeneous microtexture of the matrix developed by the internal stress arising during carbonization was investigated. The internal stress was produced due to constraint of the volume reduction of the matrix by the filler and, as a result, anisotropic regions were developed in the matrix around the filler. The internal stress occasionally caused fragmentation of the composite films during carbonization. When milled carbon fiber or graphite powder was used as a filler, fragmentation of the composite film was prevented.