SynopsisFourier. transform infrared spectra, including absorbance difference spectra, are presented which indicate that the accepted mechanism of tertiary amine-catalyzed copolymerization of cyclic anhydrides and epoxy resins requires modification. Results also show that the kinetic model is complicated by the lack of steady-state concentrations of the active species. The effect of silica filler and silane coupling agents on the reaction are also examined. a nucleophilic attack by the unbonded electron pair on the tertiary amine11,22,23; the quaternary ammonium salt zwitterion initiated the polymerization.although there is some disagreement on this point.14

The irreversible effects of moisture exposure on anhydride‐crosslinked epoxy resin films are investigated by means of Fourier‐transform infrared spectra. Hydrolytic attack of water at the ester linkages is accelerated in alkaline media and is a mechanically activated process. Matrix hydrolysis is also enhanced in the presence of inorganic fillers.

A method is presented for least-squares curve-fitting of Fourier transform infrared spectra. A demonstration of the determination of xylene solution compositions illustrates the accuracy of the method. Least-squares coefficients are shown to be valuable for the analysis of several polymer systems by digital subtraction of spectra.

Fourier‐transform infrared spectroscopy is utilized to characterize the interaction of a crosslinked epoxy matrix with sorbed water vapor. The perturbations of the epoxy vibrational spectrum are evidence for weak H bonding between water molecules and polar groups in the resin. The epoxy‐water interactions are reversible.

Fourier transform infrared spectroscopy has been used for the detection of thermally induced conformational changes in atactic poly(vinyl chloride) (PVC). Difference spectra emphasize changes in the distribution of gauche defects in the chains as functions of temperature and annealing. Specific bands in the ν(CCl) and δ(CH2) regions varied with inverse temperature, allowing a calculation of the activation energies of the rotamer species. Conformational changes were also detected in quenched PVC films as a result of annealing below the glass transition temperature, Tg.