核磁共振研究天然高分子在溶解-再生过程中的结构变化

项目名称： 核磁共振研究天然高分子在溶解-再生过程中的结构变化

项目编号： No.51273067

项目类型： 面上项目

立项/批准年度： 2013

项目学科： 一般工业技术

项目作者： 徐敏

作者单位： 华东师范大学

项目金额： 79万元

中文摘要： 纤维素、甲壳素等天然高分子是最丰富、可再生、并可生物降解的生物质大分子，如何溶解并充分利用这些材料一直是重要的研究方向。由于天然高分子本身及溶剂体系的复杂性，对其溶解-再生机理的研究还远未成熟。本项目拟从天然高分子-新溶剂体系中的氢键入手，研究氢键的破坏和重组，以及不同聚集态结构的形成过程。利用核磁共振中化学位移对氢键的敏感性、偶极相互作用和四极矩对结构和运动的敏感性来研究体系中高分子与溶剂之间的相互作用及其在空间上的信息。通过对氢键等相互作用的强弱及位置的全面描述，为天然高分子在复合溶剂体系中的状态给出清晰的物理图像；并给出不同相互作用条件下分子链运动能力及方式的不同，进而探讨凝固浴性质对链聚集的影响规律，从分子间相互作用影响分子链运动的角度对再生机理进行阐述。上述工作的完成，有助于人们从更深层次理解此类天然高分子体系的溶解-再生机理，同时为基于天然高分子的功能性材料设计提供理论依据。

中文关键词： 纤维素；碱脲溶剂体系；核磁共振；机理研究；吸附材料

英文摘要： Natural macromolecules such as Cellulose and chitin are the most abunbant, renewable, and biodegradatable natural materials. How to dissolve and apply them has long been the aim of research. Recently, some new solvent systems were develpoed. While the mechanism of the dissolving-regeneration are still unclear. In this project, we will study the break and reconstruction of the hydrogen-bond during the dissolving-regeneration processing. The formation of different aggregation structure under different regeneration condition will also be studied. The proton chemical shift in NMR is sensitive to hydrogen bond, and the dipole and quadrupole moment interaction are sensitive to structure and molecular dynamics. From these parameters, the interaction between the macromolecular chains and the solvent molecules can be studied. From the strength and location of the interactions(including hydrogen-bond), the station of the natural macromolecular chains in the complex solution system will be discribed clearly. The molecular motion under different interaction will also be discribed. Furthly, the aggregation in the process of regeneration will also be studied, and the dissolving-regeneration mechanism will be elaborated from the viewpoint of molecular interactions. With the accomplish of this project, it will be helpful for p

英文关键词： cellulose；Alkali/urea system；NMR；Mechanism research；Adsorption material