甲壳素、壳聚糖的改性

综述了壳聚糖的化学改性和物理改性。通过对壳聚糖的改性,一方面可增进其在有机溶剂中溶解行为,为进一步应用提供反应前体;另一方面增强机械或生化性质,扩展其应用范围。     

甲壳素、壳聚糖的化学改性及其衍生物应用研究进展

简要评述了甲壳素和壳聚糖化学改性的研究进展，讨论了酰化，醚化，酯化，接枝和交联等化学改性方法，简要介绍甲壳素衍生物在化妆品，医学和环保方面的应用，并提出了其发展过程中存在的一些问题，对发其发展趋势作了预测。     

甲壳素和壳聚糖在离子液体中的溶解与改性

甲壳素及壳聚糖作为生物大分子材料难溶于诸多溶剂,从而限制了其应用和修饰改性。因此,研究与开发良好的溶剂体系具有重要意义。本文首先对甲壳素及壳聚糖在各种离子液体中的溶解性能和溶解机理进行了详细综述,其次概述了甲壳素与壳聚糖在离子液体介质中进行修饰的化学反应研究(如:水解作用、酰基化反应和接枝共聚反应等),最后提出离子液体作为一类可回收循环使用的良好溶解介质将会对甲壳素及壳聚糖的实际应用和修饰改性提供更好的媒介,并拓宽甲壳素及壳聚糖的研究与应用领域。     

甲壳素/壳聚糖的配位化学和配合物应用的研究进展

本文对近二十年来有关甲壳素／壳聚糖及其衍生物与过渡金属、碱金属、稀土和贵金属配位化学研究以及有关配合物在催化、生物与医学、湿法冶金、纺织、色谱分离等方面的应用进展作了简要综述。     

电离辐射技术在甲壳素/壳聚糖改性中的应用

电离辐射技术作为一种材料改性的重要手段在天然高分子甲壳素／壳聚糖的开发研究方向有许多独特的优点,本文在甲壳素／壳聚糖的辐射加工及辐射改性的甲壳素／壳聚糖的应用两方面综述了该领域的最新进展。     

甲壳素和壳聚糖的接枝共聚改性

天然高分子甲壳素、壳聚糖由于分子链上大量存在的反应性官能团 ,易于通过自由基引发与乙烯基单体接枝共聚 ,也可与其它高分子链偶合制得接枝共聚物。通过接枝共聚改性 ,可以赋予甲壳素和壳聚糖以某些新的性能 ,扩大了其应用范围。本文对甲壳素、壳聚糖的接枝共聚改性反应进展、机理以及产物的性能等进行了介绍     

甲壳素／壳聚糖开发和研究的新动向

作为一种资源丰富、用途广泛的天然高分子化合物,甲壳素／壳聚糖产品的开发研究已引起越来越多的国家和研究机构的重视,本文对领域研究和发展的新动向进行了分析和展望。     

甲壳素／壳聚糖的化学修饰

详述了甲壳素／壳聚糖的主要化学反应所得衍生物的一些性质和应用。     

应用于生物医学领域的化学改性壳聚糖

简述了壳聚糖的化学改性方法,改性壳聚糖的特殊功能及其在生物医学领域中的应用研究进展。     

甲壳素化学及应用

甲壳素作为一种含量丰富的天然碱性多糖,近年来,其研究和开发应用越来越受到关注。本文综述了甲壳素的存在、制备和性质,尤其是化学改性及应用。     

Selective Modification of Chitin and Chitosan: En Route to Tailored Oligosaccharides

Chitin and chitosan are attractive biopolymers with enormous structural possibilities for chemical modification, creating platforms for new chemical entities with a broad scope of applications, ranging from material science to medicine. During the last few years, incredible efforts have been dedicated to the regioselective modification of these biopolymers paving the way for improved properties and tailored activities. Herein, the most recent advances in chitin/chitosan regioselective modification, reaction conditions, selectivity, and the impact on its applications are highlighted. Moreover, the recent focus on chitooligosaccharides, their regioselective and chemoselective functionalization, as well as their role in biological studies, including molecular recognition with several biological targets are also covered.     

Chitin and Chitosan Fibers

Chitin and chitosan are natural polymers extracted from various plants and animals. In recent years, these two polymers have attracted much interest because of their biodegradability, biocompatibility, wound-healing acceleration and many other unique properties. As a natural renewable resource, they offer many potential applications in a number of diversified fields. Chitin and chitosan fibers have been found useful as a biomaterial for potential applications such as sutures and wound dressings. This article presents a brief introduction to the properties of chitin and chitosan, and reviews the various attempts for the production of fibers from the two polymers. © 1997 John Wiley & Sons, Ltd.     

甲壳素,壳聚糖及其衍生物的应用

随着甲壳素,壳聚糖及其衍生物研究的迅速发展,其研究内容和应用范围越来越广泛。从发展历史,性质,提取及加工方法,应用,发展前景几个方面对其进行简要评述。     

甲壳素/壳聚糖接枝共聚反应

综述了近年来甲壳素/壳聚糖接枝共聚的研究进展。以不同单体分类,分别综述了壳聚糖与小分子乙烯基单体、大分子聚乙二醇单体、聚乳酸单体、环糊精、树状大分子接枝的研究,并介绍了新的接枝技术——生物催化接枝共聚,以及接枝壳聚糖衍生物的应用。     

Chemical Modification of Chitosan, 17

The Michael reaction of chitosan with acrylic acid was carried out successfully, even in water alone as the reaction medium. As a consequence of its good solubility in water, the reaction product, N‐carboxyethylchitosan, showed excellent biodegradable properties with standard activated sludge.

     

Chemical Modification and some Aligned Composites of Chitosan in a Filament State

The mono‐filaments (> 10 m in length) of chitosan and the blends of chitosan‐collagen, chitin‐collagen and chitin‐silk fibroin were wet‐spun. The mono‐filaments were chemically N‐modified with each of n‐fatty acid anhydrides, intra‐molecular carboxylic anhydrides, fragrant aldehydes and transition metal ions. The mono‐filament was aligned on a straight line with the mono‐filament of silk fibroin or poly(ethylene terephthalate) (PET), and a bundle of one to three mono‐filaments was coated with a medium of sericin (Se), chitosan or N‐acylchitosan to give rise to novel silk‐mimic filament composites. The filaments coated with a medium of sericin exhibited 26–27 denier for the titer, 2.46–3.36 gf · denier^?1 for the tenacity and 11.8–25.0% for the elongation. The apparent density (denier · μm^?1 in the filament diameter) of the filament composites was about 3–4 times higher than that of the mono‐filaments. Portion of fragrant aldehydes in Schiff's base was slowly hydrolyzed at room temperature by contacting with atmospheric moisture in the open air, and released from the fragrant filaments and composites. The filament composites coated with a chitosan medium were thrombogenic, and those coated with N‐acylchitosans were antithrombogenic.

An illustrated model for a silk‐mimic filament composite, N₀(N₂I‐FI).     

Present and Future Role of Chitin and Chitosan in Food

The conversion of processed discarded material into valuable by‐products and alternative specialty materials has been identified as a timely challenge for food research and development associated with numerous applications of chitinous products. Chitin, chitosan, calcareous chitin, and chitosan, N‐acetylated chitosan, N‐methylene phosphonic chitosan (NMPC), and N‐lauryl‐N‐methylene phosphonic chitosan (LMPC) are being studied as a result of their broad range of food applications. These biopolymers offer a wide range of unique applications including formation of biodegradable films, immobilization of enzymes, preservation of foods from microbial deterioration, as additives (clarification and deacidification of fruits and beverages, emulsifier agents, thickening and stabilizing agents, color stabilization), and dietary supplements. This review summarizes some of the most important developments in this field.