| Summary: | 碩士 === 國立臺北科技大學 === 有機高分子研究所 === 91 === We employ the differential scanning calorimetry (DSC) to study the Crystallization/melting behavior of polylactide acids(PLA) compounded system. Analysis of the crystallization kinetic data using the Avrami equation showed that the addition of talc as a nucleating agent resulted in an increase in crystallization rate
for all PLA compounded system. However, a saturation point can be achieved with the addition of 20% talc by weight .
Furthermore, the crystal shape was changed from a flake-like(n≒2) to a spherulite structure (n≒3), with the addition of talc. The thermal dada also reveal that the crystallinity and lamellar thickness of PLA will be slightly suppressed as the talc was added in.
The physical aging test for amorphous PLA in an Instron set-up. The relaxation test revealed that a generalized Maxwell model can fit the experimental results. The increase of aging time would increase the relaxation time. A time-temperature superposition relationship come found for this PLA relaxation behavior. In addition to relaxation, the creep test conducted and the results could be perfectly described by the KWW model. Furthermore, the relaxation time would be increased by the raise of aging time or decrease of temperature. The shifting factor of KWW equation also increases as the temperature decreases.
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