Lattice-resolution electron microscopy in structural studies of non-graphitizing carbons from polyvinylidene chloride (PVDC)

A lattice-imaging technique is applied in a study of the intimate structure of non-graphitizing PVDC C atoms heat treated in the range 803 K to 2973 K. Fine detail in the resulting electron micrographs indicates that the bulk material consists of a high proportion of intertwined crystallites comprising turbostratically packed aggregates of graphitic basal planes. Schematic models are presented incorporating the electron-microscope observations of this particular geometrical arrangement of ribbon-shaped layer planes which is thought to be responsible for the inhibition of recrystallization, i.e. graphitization at elevated temperatures. Evidence is presented which indicates that the structural transformation in PVDC differs from that of other non-graphitizing C atoms recently investigated. There is discussion of the structural factors which give rise to this effect.