Morphologies of iPP induced by its partially carbon-coated homogeneity fibers

Homogeneity fiber/matrix composites of isotactic polypropylene (iPP) were prepared with both partially carbon-coated and non-carbon-coated iPP fibers. Their morphologies produced by melt recrystallization were studied by means of polarized optical microscopy. The results show that through vacuum evaporating a thin carbon film partially on the surface of iPP fiber, the nucleation ability of the molten iPP matrix during the course of recooling has been enhanced tremendously. The early formation and high density of the iPP row nuclei formed along the partially carbon-coated iPP fibers lead to the formation of an apparent iPP transcrystalline zone in the vicinity of its precoated fiber. The high nucleation ability of the carbon-coated iPP fiber towards its homogeneity matrix may originate from the surface fixing effect of the vacuum evaporated carbon layer on the polymer samples.