Study on Crystal Morphology and Melting Properties of the Isothermally Crystallized Poly(trimethylene Terephthalate)
The spherulites’ morphology and melting properties of the poly(trimethylene terephthalate) formed in limited space at specific temperatures was studied by the polarized optical microscopy (POM). The results suggest that the spherulites’ morphology depends strongly on the temperature. When the isothermal crystallization temperatures increase from 190 to 225 oC, the spherulites’ morphology continuously changes in the following order: nonbanded → regular banded → serrated banded → nonbanded spherulites. Furthermore, the band spacing increases with the crystallization temperature. Heating the banded spherulites will cause them melt as well as the changing of the bandings, especially the bandings changes in the following order: clear → faint → clear → disappear in a certain range of temperature, which is proposed for resulting from a lamellar melting-recrystallization-remelting mechanism.
Yuan Ming Huang
M. T. Run et al., "Study on Crystal Morphology and Melting Properties of the Isothermally Crystallized Poly(trimethylene Terephthalate)", Key Engineering Materials, Vols. 428-429, pp. 259-262, 2010