International Research Center for Advanced Structural and Biomaterials, School of Materials Science and Engineering , Beihang University , Beijing 100191 , China.
Biomacromolecules Research Team , RIKEN Center for Sustainable Resource Science , 2-1 Hirosawa , Wako-shi , Saitama 351-0198 , Japan.
Biomacromolecules. 2019 Jun 10;20(6):2295-2304. doi: 10.1021/acs.biomac.9b00260. Epub 2019 May 23.
Natural silkworm silks have been applied to reinforce epoxy resin to achieve sub-ambient and impact toughness in the composite. However, the molecular interactions at the silk fiber-matrix interface of the composite are poorly understood. In this work, silk fibroin extracted from Bombyx mori silk is blended with an epoxy resin polymer system to study the molecular interactions between silk fibroin, epoxy compounds, and hardeners. The effects of chemical crosslinks between epoxy groups and hardeners or silk fibroin, as well as physical crosslinks in the β-sheet structure of silk fibroin, were discussed on the thermal stability, glass transition behavior, and mechanical properties of the blend films. A relationship between the crosslinking structure and mechanical properties for the films is proposed to enlighten on the toughening mechanisms. The findings would provide insights into forming strong and tough silk fibroin material as well as understanding the interface interactions of silk-epoxy composites.
天然桑蚕丝已被应用于增强环氧树脂，以在复合材料中实现亚环境和冲击韧性。然而，复合材料中丝纤维-基体界面的分子相互作用仍不清楚。在这项工作中，从家蚕蚕丝中提取的丝素蛋白与环氧树脂聚合物体系共混，研究丝素蛋白、环氧树脂化合物和固化剂之间的分子相互作用。讨论了环氧树脂基团和固化剂或丝素蛋白之间的化学交联，以及丝素蛋白β-折叠结构中的物理交联，对共混膜的热稳定性、玻璃化转变行为和力学性能的影响。提出了膜的交联结构与力学性能之间的关系，以阐明增韧机制。这些发现将为形成强韧的丝素蛋白材料以及理解丝-环氧复合材料的界面相互作用提供启示。
