AMPLITUDE SPECTRUM APPROACH IN DYNAMIC FT-IR SPECTROSCOPY OF UNIAXIALLY ORIENTED POLY(ETHYLENE-TEREPHTHALATE) FILMS .1. DRAW RATIO DEPENDENCE

A method of data manipulation using the dynamic magnitude spectrum and the static absorbance spectrum is applied to uniaxially drawn poly(et hylene terephthalate) films with five different draw ratios for the ev aluation of the amplitude of dynamic structural changes under a sinuso idal strain at the level of a functional group. This analysis revealed that, in the drawn film, the skeletal structures, such as the C-O bon d in the ethylene glycol unit and the phenyl ring, are susceptible to deformation by mechanical stretching, while the dynamic structural cha nges around the methylene group are small. It was assumed that the bac kbone of the polymer is responsible for the change of the mechanical p roperties induced by the drawing of the film.