| Summary: | 碩士 === 元智工學院 === 化學工程學系 === 85 === Measurements have been made using a polarized optical microsope
equipped with hot stage to investigate the transcrystallization
of PP on different fiber, namely Kevlar, carbon and PET fibers.
Both the nucleationrate and induction time at various
crystallizationtemperatures were determined.Based on the theory
of heterogeneous nucleation, the interfacial free energy
difference function of PP on different fibers were determinted
and compared tothat in the bulk matrix. The morphology of
various fibers surfac is observed using AFM and SEM. The
relationon between surface morphology and nucleation ability of
fiber was discussed in details. Effect of stress on the
inductiontime, nucleation rate and linear crystal growth rate
arestudied by pulling single fiber embedded in the PP melt with
a smalltensile testing machine. Experimental results shows that
the nucleation rate increases with increasingpulling rate. The
effect of fiber-pullingon the crystal growth rate isnegligible
at high crystallization temperatures However, a pronounced
increacein growth rate was found at low crystallization
tempeeratures. The regime transition, based on Hoffman's theory
was applied and discussed here.
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