Glass transition and cooperative rearranging regions in amorphous thermoplastic nanocomposites

Abstract

The aim of this work was to study the effect of nanofillers on the structural relaxation phenomena occurring in amorphous poly(ethylene-terephthalate)/poly(cyclohexane-dimethanol terephthalate) copolymer (PET/PCHDMT) nanocomposites in correspondence with the glass transition temperature. PET/PCHDMT nanocomposites were prepared by melt mixing with an organicmodified montmorillonite at different processing temperatures. Differential scanning calorimetry analysis revealed that addition of the organic modifier alone causes a decrease of the glass transition temperature and an increase of the specific heat discontinuity. Nanocomposites showed a higher glass transition temperature and a lower specific heat discontinuity compared with samples obtained by adding organic modifier to PET/PCHDMT. Both effects were more relevant for samples processed at lower temperatures. Therefore, the glass transition temperature was studied by introducing the concept of fictive temperature and relaxation time. It was found that nanocomposites have a higher apparent activation energy and an increased size of cooperatively rearranging regions compared with neat PET/PCHDMT. Both effects are more relevant for nanocomposites processed at lower temperatures. All the discussed effects are explained by considering the enhanced confinement of PET/PCHDMT macromolecules, due to the presence of intercalated lamellae of organofiller. The efficiency of intercalation is increased by decreased processing temperature, which involves an increase of the nano-confinement area of the polymer.


Autore Pugliese

Tutti gli autori

  • A.Greco , R. Gennaro , M. Rizzo

Titolo volume/Rivista

POLYMER INTERNATIONAL


Anno di pubblicazione

2012

ISSN

0959-8103

ISBN

Non Disponibile


Numero di citazioni Wos

18

Ultimo Aggiornamento Citazioni

28/04/2018


Numero di citazioni Scopus

17

Ultimo Aggiornamento Citazioni

28/04/2018


Settori ERC

Non Disponibile

Codici ASJC

Non Disponibile