单 位：
北京林业大学林木分子设计育种高精尖创新中心林木生物质化学北京市重点实验室
关键词：
木聚糖;化学改性;醚化;酯化;膜材料;阻隔性能
摘 要：
木聚糖作为阔叶木和禾本科植物半纤维素的主要成分,因其来源广、可再生、可降解等特点,近年来成为备受关注的功能天然高分子。木聚糖基膜材料因气体阻隔性能优异、生物相容性好、环境友好等特性,在造纸、食品包装、涂层、生物医药材料领域展现出巨大的应用潜力。但是木聚糖具有水溶性和成膜性较差、膜材料极易吸湿和力学强度低等缺陷,极大地限制了其规模化、商业化应用,因此,如何改善这些缺陷将是木聚糖研究与应用的热点和难点。木聚糖通过化学改性可赋予其刺激响应性、离子性、热塑性等新的特性,增加木聚糖的溶解性、疏水性和改善其可加工性能,是实现木聚糖在功能材料制备与应用的重要途径。笔者总结了近年来木聚糖醚化、酯化、氧化和接枝共聚改性的研究进展,探讨了反应条件对木聚糖衍生物取代度、产率和性能的影响;总结了近年来木聚糖基膜材料的制备策略与应用,如通过内增塑、外增塑、聚合物增强等实现了木聚糖基膜材料的高效制备,并探讨了其在应用过程中的优势及缺陷,为木聚糖今后研究和应用提供新的方法和思路。
译 名：
Research progress on xylan derivatives and xylan-based films
作 者：
PENG Feng;RAO Jun;Advanced Innovation Center of Tree Molecular Design and Breeding,Beijing Key Laboratory of Lignocellulosic Chemistry,Beijing Forestry University;
关键词：
xylan;;chemical modification;;etherification;;esterification;;films;;barrier property
摘 要：
As the main type of hemicelluloses of hardwood and gramineae plants,xylan received much attention as a functional natural polymer material in recent years due to its low cost,renewable and degradable characteristics. It is not only the main component of hemicelluloses in hardwood and gramineous plants,but also the main component of non-cellulose polysaccharide in plant cell walls. Xylan is formed by a main chain of β-( 1,4)-linked xylopyranose units,which can be substituted at the C-2 and/or C-3 positions by 4-O-methylglucuronic acid( MeGlcA) groups,arabinose,and O-acetyl groups. O-acetyl-4-O-methylglucuronoxylan,arabino-4-O-methylglucuronoxylan,and arabinoxylans are the most common xylans. Xylan can be obtained from lignocellulosic biomass by the alkali extraction,and the acetyl groups will be removed under the conditions. The hydroxyl groups of xylan can be modified for preparing the xylan derivatives. Xylan-based films have shown great application potential in papermaking,food packaging,coating,and biomedical materials due to their excellent gas barrier property,good biocompatibility,and biodegradability.However,the commercial application scale of the films is limited due to their poor dissolving,poor film-forming,extreme moisture-absorbing,and poor mechanical property. Therefore,the method to overcome these defects will be the hotspot and difficulty of the xylan research and application. Chemical modification of xylan imparts it to new characteristics,such as stimulation response,ionic property,thermo-plasticity,and improvement of the solubility,hydrophobic properties,and processing performance. It is an important way to realize the preparation and application of xylan in functional materials. In this paper,the research progress of etherification,esterification,oxidation,and graft copolymerization of xylan is introduced. The effects of reaction conditions on the degree of substitution,yield and performance of xylan derivatives are discussed. The etherification reaction of xylan is to use various etherifying agents such as halogenated compounds,epoxy compounds and olefinic monomers to react with xylan in an alkaline environment.The esterification modification of xylan refers to the corresponding esterified derivatives of xylan formed by the reaction of hydroxyl group on the molecular chain of xylan reacts with an acid. Graft copolymerization of xylan involves the introduction of polymers with specific functions onto the xylan backbone. In addition,the preparation strategies and applications of xylan-based films are reviewed. The efficient preparation methods,such as internal plasticization,external plasticization,polymer reinforcement,are used for achieving the xylan-based films. The advantages and drawbacks of xylan in the application process are discussed,which can provide new design ideas and directions for the research and application of xylan in the future.
