THE RELEVANCE OF THE SURFACE-STRUCTURE AND SURFACE-CHEMISTRY OF CARBON-FIBERS IN THEIR ADHESION TO HIGH-TEMPERATURE THERMOPLASTICS .1. SURFACE-STRUCTURE AND MORPHOLOGY

The surface structure and morphology of several high strength polyacry lonitrile (PAN) based carbon fibres was studied with the scanning elec tron microscope (SEM) on the micrometre scale and the scanning tunnell ing microscope (STM) down to the atomic scale. In addition, active sur face area measurements were made to determine the number of bonding si tes/unit area. Prior to the observations, the surfaces of some of the samples were subjected to either the commercial surface treatment or t o oxidation in air or ozone in our laboratory. The roughness and numbe r of bonding sites on each fibre surface was determined. These values will be correlated with the mechanical properties of composites made w ith these fibres and thermoplastic polymers in Part III of this study.