Colloid and Polymer Science

, Volume 292, Issue 6, pp 1365–1374 | Cite as

Rigid amorphous fraction and melting behavior of poly(ethylene terephthalate)

  • Maria Cristina Righetti
  • Michele Laus
  • Maria Laura Di Lorenzo
Original Contribution


The multiple melting behavior of poly(ethylene terephthalate) (PET) is generally attributed to the fusion of original crystals recrystallized during the heating at conventional scanning rate. In the present study, the triple and double melting behavior that is observed after isothermal crystallization at T c lower and higher than 215 °C, respectively, is put in relation with the presence and absence of rigid amorphous fraction around the original primary crystal lamellae. The complex melting behavior is explained by assuming that two different morphologies of primary crystals develop during crystallization at temperatures lower than 215 °C, in a proportion that is a function of the crystallization temperature: chain cluster aggregations with a high percentage of rigid amorphous fraction on the boundaries and small crystals with a high percentage of adjacent reentry folding and reduced constraints at the amorphous/crystal interphase. These distinct morphologies differently transform upon heating at low scanning rate, originating two endotherms. On the contrary, after crystallization at T c  > 215 °C, all the primary crystalline structure, which probably are characterized by the same morphology made of tightly chain folded lamellae and absence of rigid amorphous fraction, undergo the same reorganization route, originating a single endotherm.


Rigid amorphous fraction Interphase Chain mobility Temperature-modulated calorimetry 


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Copyright information

© Springer-Verlag Berlin Heidelberg 2014

Authors and Affiliations

  • Maria Cristina Righetti
    • 1
  • Michele Laus
    • 2
  • Maria Laura Di Lorenzo
    • 3
  1. 1.Istituto per i Processi Chimico-FisiciConsiglio Nazionale delle Ricerche, INSTM, UdR PisaPisaItaly
  2. 2.Dipartimento di Scienze e Innovazione TecnologicaUniversità del Piemonte Orientale ‘A. Avogadro’, INSTM, UdR AlessandriaAlessandriaItaly
  3. 3.Istituto per i Polimeri, Compositi e BiomaterialiConsiglio Nazionale delle RicerchePozzuoli (NA)Italy

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