Polysaccharides 1 -» 3 bond, frequency

High Frequency Relaxation As illustrated in Figure 2.11, in dry annealed chitin samples, a high frequency secondary relaxation is observed, the so-called -relaxation. This relaxation is found in other polysaccharides [66] and is thought to be associated with molecular motions via the glucosidic bond [20, 61]. The fitting parameter a = 0.45 — 0.49 0.08 and the intensity of [)-relaxation have a weak dependence on temperature. = 1 values in the HN model describe a symmetric relaxation by the simple Cole-Cole model. It can be seen... 

The IR spectra exhibited low frequency shifts of absorption maxima in the range 3600-3100 cm" that correspond to hydroxyl stretching vibrations by 130-140 cm and of absorption maxima of C-0 ether stretching vibrations in the py ranose and fura-nose rings at 1200-1100 cm by 19-20 cm". This may indicate formation of intermo-lecular H-bonds between INAH and the polysaccharides. Furthermore, the absorption band at 1750 cm that is typical of carboityl vibrations in the range 1500-1750 cm weakened. An absorption band of medium strength appeared at 1550 cm and was attributed to vibrations of the pyridine ring of INAH. 

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