TG/FT-IR - AN ANALYSIS OF THE CONDITIONS AFFECTING THE COMBINED TG/SPECTRAL RESPONSE

The results of TG/FT-IR measurements performed on hydrated beta-cyclodextrin at different heating rates and with different carrier gas fluxes are reported. Tt is shown that the shape of the spectral curve (either Gram-Schmidt reconstruction or integrated specific absorbance) and its degree of matching with the DTG curve depend on both the TG heating rate and the carrier gas flow rate. Namely, it is the relative rate of the reaction and of the TG purging that determines the spectral response. The results obtained are wholly accounted for by utilizing a simple ''dispersive'' definition, as recently proposed by us, for the ''relative intensity'' of the spectral curve.