Application of dynamic 2D FTIR to cellulose
2000; Elsevier BV; Volume: 22; Issue: 1-2 Linguagem: Inglês
10.1016/s0924-2031(99)00063-6
ISSN1873-3697
AutoresBarbara Hinterstoisser, Lennart Salmén,
Tópico(s)Polysaccharides Composition and Applications
ResumoCellulose, the dominant polymer in the biosphere, is a homopolysaccharide composed of (1,4)-β-d-glucopyranose. Interactions between and within the cellulose polymer chains are mainly determined by inter- and intramolecular hydrogen bonds, which are therefore mainly responsible for mechanical properties of cellulosic materials. The coupling of dynamic mechanical analysis (DMA) and 2D step-scan Fourier transform infrared (FTIR) spectroscopy, is shown to be a very promising way of investigating these submolecular interactions in cellulosic materials. The broad and unstructured band in the OH-stretching vibration region (3100 and 3700 cm−1) of the cellulose vibrational spectra, which contains information about the intra- and intermolecular hydrogen bonds, can be unraveled by this new technique. In the experiments reported here, cellulose sheets have been stretched sinusoidally at low strains while being irradiated with polarized infrared light. For the obtained dynamic IR signals (the in-phase and the out-of-phase responses of the sample), the dynamic IR cross-correlation was defined. It consists of two terms which are referred to as the synchronous and the asynchronous 2D infrared correlation intensities. In the 2D spectra, obtained by DMA–FTIR, several distinct peaks are observed in the OH-range between 3700 and 3100 cm−1 which may be related to specific interactions.
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