Structure and properties of silkworm cocoon (Bombyx mori) treated by hot pressing

摘要

The silkworm cocoon has outstanding mechanical properties due to the specific composite structure. However, the individual cocoon is small and irregular in shape which dramatically hinders its application in artificial composites. Here, rectangular pieces of silkworm cocoons were cut and combined into large sheets by means of hot pressing. The structure and properties of compressed cocoon pieces were investigated. The thickness and porosity of pieces are significantly decreased at the high pressure, besides silk fibers are more deformed and bonded at high temperature cause of sericin's softening and fusion. Tensile strength and modulus are remarkably increased compared to those of the raw cocoon, and so do the interlayer bonding. The stable thermal property of the compressed cocoons demonstrates that compression at a high temperature has little harm to cocoons. Therefore, hot pressing is a practical way to build artificial cocoon composites for engineering applications. (C) 2017 Published by Elsevier Ltd.