Micro-Raman study of PET single fibres under high hydrostatic pressure: phase/conformation transition and amorphization

The micro/nano structural evolution of a PET single fibre under hydrostatic pressure has been studied by Raman micro spectroscopy in a diamond anvil cell (DAC). Different bands in the Raman spectra were used as probes: the low wavenumber collective modes (<250 cm(-1)) representative of the long-range chain organization, as well as the stretching and bending amide and aromatic ring modes representative of the local chain behaviour. The in situ analysis at different pressures shows an evolution from an axial oriented trans-conformation to an amorphous, isotropic material, i.e. the reverse transformation observed during the process of drawing the fibre from an isotropic amorphous precursor. Copyright (C) 2007 John Wiley & Sons, Ltd.