Transcrystallinity phenomena in a polypropylene/kvelar fiber system I: influence of crystallization conditions

The isothermal crystallization from the melt of isotactic polypropylene in the presence of Kevlar 49 fibers has been investigated. The nucleating ability of the fibers was demonstrated, and the presence of extensive transcrystalline regions was related to crystallization parameters, such as crystallization temperature, melt precrystallization temperature, and residence time at precrystallization temperature. The results are discussed in terms of the presence of heterogeneities in the bulk and preformed self-seeded nuclei located in the anfractuosities of fiber surfaces.