NIR SPECTROSCOPY ANALYSIS AND ITS APPLICATIONS TO POLYMERS ANALYSIS

The fundamental studies of spectra and dynamics of coupled vibrational high energy state of small polyatomic molecules are subject to a larg e development due to new experimental techniques. The great anharmonic ity of C-H, N-H, O-H groups give absorptions in the near IR region and have been used to analyse and characterise polymers,often in conjunct ion with statistical packages. In the presence of highly over-lapping and low solution spectra, chemometric methods are the only way to obta in accurate results. Nevertheless the analyst would be more at ease us ing quantitative hand analysis (with appropriated treatment) if the sp ectra are of high quality and band assignments available in the open l iterature. Often the weak absorbance in the NIR region allows to study more realistic polymeric samples than classic transmission technique in the mid IR region using very thin samples and some problems associa ted with mid IR sampling are alleviated through the use of NIR spectro scopy. High analytical capabilities of NIR spectroscopy made this tech nique very suitable for rapid and non-destructive polymeric composite analyses in terms of ease of sampling, cost and reliability. However, NIR spectra of polymers need to be interpreted, as in the case of the mid IR spectra, for better utilization of this technique.