Poly(propylene terephthalate/2,6-naphthalate) random copolyesters (PPT-PPN) were synthesized and characterized from the mol. and thermal point of view. All the polymers showed a good thermal stability. The main effect of copolymn. was a lowering in the crystallinity and a decrease of Tm respect to homopolymers. WAXD measurements indicated that PPT-PPN copolymers are characterized by isodimorphic cocrystn. The defect free energies, calcd. on the basis of the inclusion model proposed by Wendling and Suter, indicated that the amt. of PT units incorporated in the poly(propylene 2,6-naphthalate) (PPN) _ crystals is higher than the amt. of PN units which cocrystallizes in the poly(propylene terephthalate) (PPT) cryst. phase, probably due to the larger molar volume of PN units compared to PT ones. Amorphous samples showed a monotonic increment of Tg as the content of PN units is increased, due to the stiffening effect of naphthalene rings in the chain. Finally, the Fox equation described well the Tg-compn. data.

Synthesis and characterization of poly(propylene terephthalate/2,6-naphthalenate) random copolyesters.

LORENZETTI, CESARE;FINELLI, LARA;LOTTI, NADIA;VANNINI, MICAELA;GAZZANO, MASSIMO;BERTI, CORRADO;MUNARI, ANDREA
2005

Abstract

Poly(propylene terephthalate/2,6-naphthalate) random copolyesters (PPT-PPN) were synthesized and characterized from the mol. and thermal point of view. All the polymers showed a good thermal stability. The main effect of copolymn. was a lowering in the crystallinity and a decrease of Tm respect to homopolymers. WAXD measurements indicated that PPT-PPN copolymers are characterized by isodimorphic cocrystn. The defect free energies, calcd. on the basis of the inclusion model proposed by Wendling and Suter, indicated that the amt. of PT units incorporated in the poly(propylene 2,6-naphthalate) (PPN) _ crystals is higher than the amt. of PN units which cocrystallizes in the poly(propylene terephthalate) (PPT) cryst. phase, probably due to the larger molar volume of PN units compared to PT ones. Amorphous samples showed a monotonic increment of Tg as the content of PN units is increased, due to the stiffening effect of naphthalene rings in the chain. Finally, the Fox equation described well the Tg-compn. data.
2005
C. Lorenzetti; L. Finelli; N. Lotti; M. Vannini; M. Gazzano; C. Berti; A. Munari
File in questo prodotto:
Eventuali allegati, non sono esposti

I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.

Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/11585/8464
 Attenzione

Attenzione! I dati visualizzati non sono stati sottoposti a validazione da parte dell'ateneo

Citazioni
  • ???jsp.display-item.citation.pmc??? ND
  • Scopus 29
  • ???jsp.display-item.citation.isi??? 26
social impact