高性能半纤维素基有机-无机杂化膜材料制备与性能研究

Petroleum based materials have some disadvantages such as non-renewable, non-biodegradable, environment pollution. The formulation of new biodegradable materials from the biomass is becoming an increasingly acknowledged alternative for petroleum based material, and has become the major needs of the sustainable development strategy. Hemicelluloses are the second most abundant plant renewable materials after cellulose. Due to the complexity of their structure, compared to cellulose, hemicelluloses are underutilized. In this project, fractional purification of hemicelluloses will be investigated for the effective,low-cost fractional purification technology, and their mechanisms will be clarified. In addition, a series of hemicelluloses-based polymer/clay nanocomposites (film) will be prepared by hybrid of hemicelluloses and their derivatives, montmorllonite, chitosan, and nano-cellulose whiskers. The preparation mechanisms of film, such as non-covalent bonding interaction (hydrogen and ionic bonds), interface behavior, nano-effect, percolation, and electrostatic interaction will be elucidated. In addition, various properties of these film materials are systematically discussed, such as the low-oxygen permeability, moisture resistance property, antibiotic property, mechanical strength and biological properties. Based on the structure, properties and function of films, their relationships at the molecular level were clarified. This project will provide a theoretical basis and new technologies for the preparation and application of the hemicelluloses-based biodegradable film materials.

石油基材料具有不可再生、难降解、污染严重等缺点，以农林生物质为基质制备新型可降解材料补充或逐步替代石油基材料已成为可持续发展战略的重大需求。半纤维素含量在生物质中约占1/3，但由于其结构复杂性导致半纤维素一直未被高值化利用。本项目在提出半纤维素高效、低成本分离纯化技术及阐明其机理的基础上，以半纤维素和蒙脱石为原料，壳聚糖和纳米纤维素为辅助增强材料，制备高性能的类贝壳珍珠层结构的半纤维素/蒙脱石杂化膜材料，阐明其杂化复合机理（非共价键作用力、界面行为、纳米效应、浸透及静电作用），并对系列膜材料的隔氧性、阻湿性、抗菌性、力学及生物学性能进行系统研究，从分子水平揭示半纤维素基膜材料的结构-性质-功能的构效关系，为半纤维素膜用于食品包装行业提供理论依据和新技术。

本研究以农林生物质（慈竹）为原料提取半纤维素，研究半纤维素的分级纯化和半纤维素的化学结构，然后以制备的离子型半纤维素为原料，与蒙脱石和壳聚糖复合制备半纤维素基可降解膜材料。经过三年的努力研究，提出了梯度浓度硫酸溶液技术快速分级纯化半纤维素，揭示了其浓度变化与半纤维素分支度及结构之间的规律及关系。利用阳离子半纤维素、蒙脱土为原料，PVA、纳米甲克素、壳聚糖为增强剂，制备出高性能的半纤维素基膜材料（拉伸强度达58MPa），阐明了其复合机理，揭示了其构效关系。在以上研究的基础上，本研究还利用富含半纤维素的木材自水解物（制浆厂的水热预处理液）替代阳离子半纤维素制备出力学性能可达124MPa的有机无机复合膜材料，该材料还具很好的热稳定性、阻燃性和憎水性。该部分研究工作为我的后续研究提供了新的思路和方向。本项目研究结果为制备高附加值的半纤维素基复合膜材料提供了的制备及应用提供理论依据和新技术，并有望将此类复合材料推广应用至包装以及阻燃材料领域中。.经过三年的努力探索，在Chemical Engineering Journal, ACS Sustainable Chemistry & Engineering, Carbohydrate Polymers, Industrial & Engineering Chemistry Research等期刊上发表论文12篇，其中SCI收录10篇（JCR一区论文6篇，二区论文3篇），EI收录论文1篇；申请发明专利3件，其中授权2件；团队成员2名教师职称由讲师升为副教授；培养了博士生1名，硕士生2名；在项目执行期间，项目负责人入选了中组部“青年拔尖人才”支持计划、2017年度“青年长江学者”奖励计划、北京林业大学杰出人才培育计划项目；获得了第十三届中国林业青年科技奖。