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A comparison between PA‐FTTR and FT‐Raman spectroscopies in the structural analysis of annealed injected‐moulded poly (ethylene terephthalate)
Author(s) -
Quintanilla Luis,
RodríguezCabello José Carlos,
Merino Juan Carlos,
Pastor Jose María
Publication year - 1995
Publication title -
macromolecular symposia
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.257
H-Index - 76
eISSN - 1521-3900
pISSN - 1022-1360
DOI - 10.1002/masy.19950940112
Subject(s) - raman spectroscopy , fourier transform infrared spectroscopy , crystallinity , materials science , infrared , analytical chemistry (journal) , annealing (glass) , ethylene , infrared spectroscopy , polymer , chemistry , chemical engineering , organic chemistry , optics , composite material , physics , engineering , catalysis
With the introduction of the Fourier Transform technique in Raman spectroscopy (FT‐Raman) and the development of new methods in FTIR, such as FTIR with photoacoustic detection (PA‐FTTR), vibrational spectroscopy has been launched into a new era of application in polymer chemistry and physics. This work provides a comparative study between PA‐FTIR and FT‐Raman techniques in which the potentials and limitations of these two methods are investigated by following and analyzing structural variations that take place in annealed injected‐moulded poly(ethylene terephthalate) (PET). Both spectroscopic techniques appear to be suitable to detect structural changes that occur in PET submitted to different annealing temperatures. We suggest that these variations are directly related to conformational rather than crystallinity changes. The main drawbacks of PA‐FTIR are the lengthy adquisition time of spectra and the photoacoustic saturation that can appear in regions with quite high optical absorption coefficient. Conversely, FT‐Raman technique does not suffer from neither of these problems. However, the sensitivity to structural changes of certain infrared bands seems to be higher than that of analogous Raman bands and small structural details such as the regularity of chain folding, can only be detected in the infrared spectra.