A detailed morphological analysis of the melting process of poly(butylene terephthalate) (PBT) is presented. Investigations were conducted by polarizing optical microscopy, coupling the measurement of depolarized light intensity with examination of morphology of PBT spherulites during their fusion. These analyses allowed to prove that the spherulitic superstructure of PBT developed upon isothermal crystallization from the melt does not vary with temperature until complete melting takes place, despite the large reorganization involved in the fusion process. It is thus shown that the double melting behavior commonly observed in PBT does not arise from the presence of various spherulitic morphologies with different thermal stabilities, and the structural changes caused by the reorganization processes do not involve variations in the spherulitic morphology. The recrystallization of PBT above the apparent melting point was also analyzed, and the role of memory effects of crystalline precursors remaining in the melt was discussed.
Morphological analysis of poly(butylene terephthalate) spherulites during fusion
M L Di Lorenzo;M C Righetti
2004
Abstract
A detailed morphological analysis of the melting process of poly(butylene terephthalate) (PBT) is presented. Investigations were conducted by polarizing optical microscopy, coupling the measurement of depolarized light intensity with examination of morphology of PBT spherulites during their fusion. These analyses allowed to prove that the spherulitic superstructure of PBT developed upon isothermal crystallization from the melt does not vary with temperature until complete melting takes place, despite the large reorganization involved in the fusion process. It is thus shown that the double melting behavior commonly observed in PBT does not arise from the presence of various spherulitic morphologies with different thermal stabilities, and the structural changes caused by the reorganization processes do not involve variations in the spherulitic morphology. The recrystallization of PBT above the apparent melting point was also analyzed, and the role of memory effects of crystalline precursors remaining in the melt was discussed.File | Dimensione | Formato | |
---|---|---|---|
prod_168986-doc_735.pdf
solo utenti autorizzati
Descrizione: Morphological analysis of poly(butylene terephthalate) spherulites during fusion
Dimensione
1.68 MB
Formato
Adobe PDF
|
1.68 MB | Adobe PDF | Visualizza/Apri Richiedi una copia |
I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.