Two-dimensional step-scan FTIR:: a tool to unravel the OH-valency-range of the spectrum of Cellulose I

This article presents the results of the first application of dynamic mechanical analysis (DMA) coupled with 2D step-scan Fourier transform infrared (FTIR) spectroscopy, to cellulose. It is demonstrated that the broad hydroxyl infrared absorption band between 3700 and 3000 cm(-1) in the cellulose infrared spectra could be separated into distinct bands by this dynamic rheo-optical investigation using FTIR-spectroscopy as detecting system. The responses of the OH-groups to an external perturbation were recorded as in-phase and out-of-phase spectra. The cross correlation of these spectra gave the 2D synchronous and asynchronous plots, which showed clearly separated bands in the OH-vibration range and the relation of the OH-groups to each other. It is demonstrated that it is possible to establish relations between the OH-bands and the cellulose structure.