Characterization of chitin, chitosan and their carboxymethyl derivatives by differential scanning calorimetry
Characterization of chitin, chitosan and their carboxymethyl derivatives by differential scanning calorimetry
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DOI：
10.1016/s0144-8617(01)00320-4
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发表时间：
2002-08-01
影响因子：
11.2
通讯作者：
Tharanathan, RN
中科院分区：
文献类型：
--
作者：
Kittur, FS;Prashanth, KVH;Tharanathan, RN
采用差示扫描量热法（DSC）对甲壳素、壳聚糖及其O,N-羧甲基衍生物进行表征，主要关注不同乙酰基和羧甲基含量水平下物理和化学结构的变化。热分析图的特征在于分别对应于水蒸发和聚合物分解的吸热和放热。然而，每个吸热或放热峰温度和面积随着大分子的一级和高级结构的变化而变化。发现吸热焓随着氨基和羧甲基含量的增加而增加。此外，在羧甲基衍生物的情况下，尽管存在大量的无定形内容物，但没有观察到玻璃化转变。在分解过程中，分解峰温度和面积随着分子量（MW）、乙酰基和羧甲基含量的变化而变化。采用理论基础将反应热、H、脱乙酰化程度(%DD)和羧甲基化程度(DS)关联起来。当对应的峰面积和峰高针对 %DD 和 DS 进行绘制时，获得了良好的相关性。 (C) 2002 Elsevier Science Ltd. 保留所有权利。
Chitin, chitosan and their O,N-carboxymethyl derivatives were characterized by differential scanning calorimetry (DSC) mainly focusing on changes in physical and chemical structures at different levels of acetyl and carboxymethyl contents. The thermograms were characterized by endo- and exotherms corresponding to water evaporation and decomposition of the polymer, respectively. However, each endo- or exothermic peak temperature and area changed as a function of primary and higher order structures of the macromolecule. It was found that the enthalpy value for endotherm increased with increase in amino and carboxymethyl contents. Further, in the case of carboxymethyl derivatives, no glass transition was observed despite the presence of substantial amount of amorphous content. During decomposition, the decomposition peak temperature and area changed as a function of molecular weight (MW), acetyl and carboxymethyl contents. A theoretical basis was adopted to correlate the heat of the reaction,),H, to the degree of deacetylation (%DD) and carboxymethylation (DS). A good correlation was obtained when the corresponding peak area and peak height were plotted against %DD and DS. (C) 2002 Elsevier Science Ltd. All rights reserved.