Abstract Herein we report new dielectric relaxation processes at high frequency (ca. 1.2•108 Hz) in polysaccharides pellets (cellulose, chitin, chitosan, starch and amylopectin) that are traceable to strong OH–H2O interactions. Temperature dependence of high frequency dielectric relaxation behavior is investigated using dielectric spectroscopy. In situ temperature FTIR, XRD and TGA measurements are studied to assess relaxation processes related to vibration of OH groups. Upon heating below the glass transition there appears an Arrhenius-type dependence with negative activation energy; this is due to re-orientation of dipoles to lower energy. Upon further heating a glass transition is observed and then there appears another Arrhenius-type process with positive activation energy due to the increasing of random thermal motions of chains, water molecule evaporation and hydrogen bonding destruction. In dry samples the activation energies of this relaxation are practically zero because no exist water molecules and OH groups of polysaccharides are trapped in a potential well.

中文翻译：

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在水存在下探索多糖的分子相互作用

摘要在此我们报告了多糖颗粒（纤维素、几丁质、壳聚糖、淀粉和支链淀粉）中高频（约 1.2•108 Hz）的新介电弛豫过程，这些过程可追溯到强 OH-H2O 相互作用。使用介电光谱研究高频介电弛豫行为的温度依赖性。研究了原位温度 FTIR、XRD 和 TGA 测量，以评估与 OH 基团振动相关的弛豫过程。在玻璃化转变以下加热时，出现具有负活化能的 Arrhenius 型依赖性；这是由于偶极子重新定向以降低能量。在进一步加热时观察到玻璃化转变，然后由于链的随机热运动的增加，出现另一个具有正活化能的阿伦尼乌斯型过程，水分子蒸发和氢键破坏。在干燥样品中，这种弛豫的活化能实际上为零，因为不存在水分子，多糖的 OH 基团被困在势阱中。