The effects of addition of glass fiber and HMS4 carbon fiber on the
crystallization of nylon 6,6 has been investigated using DSC and polarized
optical Microscopy (POM). DSC observations indicate that HMS4 fiber lowers
the supercooling required to initiate crystallization. A transcrystalline
layer is also observed in the near-fiber region of carbon fiber-reinforced
composites after DSC. The presence of transcrystallinity and the earlier
onset of crystallization for this composite are due to heterogeneous
nucleation on carbon fiber surfaces. DSC Measurements of nylon 6,6 with
glass fibers show supercoolings similar to those of neat nylon 6,6.
Transcrystallinity is also absent in the glass-reinforced composites. These
glass fibers appear to be weak nucleation catalysts. Different
transcrystalline layer thickness is found to be influenced by thermal
processing condition. In addition to transcrystallinity, the HMS4 carbon
fiber also influences the bulk morphology of the nylon 6,6.