二氧化硅的氢键与异相成核作用下木薯淀粉回生机理研究

淀粉是可再生、可降解的绿色天然高分子材料。淀粉回生现象导致其结构与性能发生变化，二氧化硅在改善淀粉材料的力学、耐热和耐水性能等方面具有独特的优势，而二氧化硅对淀粉回生机理方面的研究鲜有报道。本项目以木薯淀粉为研究对象，采用熔融法制备木薯淀粉/二氧化硅复合材料，将宏观和微观研究手段相结合，基于二氧化硅的氢键作用和异相成核原理，研究不同用量、粒径及表面性质的二氧化硅与淀粉的相互作用机制，获取淀粉回生过程的热力学参数，建立回生动力学方程，获得二氧化硅对木薯淀粉回生速率、回生指数的影响规律；研究木薯淀粉/二氧化硅复合材料回生过程氢键变化规律，揭示氢键与回生行为关系；探讨淀粉回生过程中二氧化硅的分布、迁移、界面黏结机制，获得二氧化硅对木薯淀粉聚集态、颗粒、晶体、层状结构的影响规律，揭示淀粉/二氧化硅复合材料的结构与回生行为关系。通过该研究为淀粉回生机理的完善、淀粉材料性能的提高提供理论基础和方法。

Starch is a green natural renewable and degradable polymer materials. The retrogradation phenomenon of starch would lead to the changes in the structure and properties. Silica has unique advantages in improving mechanical properties, thermal stability and water resistance of starch material, however the effect of silica on starch retrogradation mechanism has been rarely reported. In this project, cassava starch as the research object, the cassava starch/silica composites are prepared via melt blending method by the combination of macro and micro research methods. Based on the hydrogen bonding interaction theory and heterogeneous nucleation theory, the effect of different content, particle size and surface characteristics of silica on the interaction of starch is investigated. The thermodynamic parameters are obtained starch during retrogradation process, and the retrogradation kinetics equation will be established. The effect of silica on retrogradation rate and index of cassava starch are obtained. The changes of hydrogen bond of cassava starch/silica composite during retrogradation process are explored, and the relationship between hydrogen bonding and retrogradation behavior is revealed. The dispersion, migration and interface bonding conditions of silica particle during retrogradation process of the cassava starch are investigated. The effect of silica on aggregation, granules, crystal, layer structure cassava starch is researched, in order to explore the relationship between structures and retrogradation behavior. Through the research would provide the theoretical basis and method for the perfection of retrogradation mechanism and enhancement of properties of starch materials.