Investigation of Structural Morphology and Mechanical Behavior of Muga Silkworm (Antheraea Assamensis) Cocoons

ABSTRACT

Silkworm cocoonsare an insect engineered multi-layered bio-material constructs that holds a matchless position in textile as well as bio-medical industry. We have investigated the structure and morphology of muga silkworm Antheraea assamensis cocoons that are endemic and semi-domestically reared in the Brahmaputra valley of Assam and other neighboring regions of North-east India. Further, the contribution of obtained structural features toward the mechanical properties of cocoon and silk fibers are quantified and discussed. We identified the nonwoven fiber architecture in the muga cocoons with continuous silk filaments conglutinated in the sericin matrix and calcium oxalate crystals on the outer surface. The measured properties of the cocoon structure fall between those of domesticated bombyx mori (mulberry) and other wild cocoons (temperate and tropical tasar cocoons). The study also highlights the feeble and low compactness nature of muga cocoons that requires a meticulous breeding program aiming at genetic improvement of muga silkworms in the form high-yielding and compact cocoons with better characteristics for commercial utilization.

摘要

蚕茧是一种昆虫工程化的多层生物材料结构，在纺织和生物医药工业中占有无可比拟的地位. 我们研究了阿萨姆邦雅鲁藏布江流域及印度东北部其他邻近地区特有的半家养蚕茧的结构和形态. 进一步，定量讨论了所获得的结构特征对蚕茧和蚕丝纤维力学性能的影响. 我们在木瓜茧中发现了无纺纤维结构，丝胶基质中粘着连续的丝丝，外表面有草酸钙晶体. 蚕茧结构的测量特性介于家蚕（桑蚕）和其他野生茧（温带和热带塔萨尔茧）之间. 这项研究还强调了木瓜茧的脆弱性和低密性，这就需要一个细致的育种计划，以期对木瓜蚕进行遗传改良，形成高产、致密的茧，使其具有更好的商业利用特性.

KEYWORDS:

• Antheraea assamensis
• bio-meterial
• silkworm cocoons
• structural morphology
• mechanical behavior
• compactness

关键词:

• 阿萨门尼斯
• 生物材料
• 蚕茧
• 结构形态
• 机械性能
• 紧度

Acknowledgments

The authors would like to acknowledge the Focus Incubation Center for 3D weaving and structural composites, Department of Textile & Fiber Engineering, Indian Institute of Technology Delhi and Post Cocoon Technology section of Central Muga Eri Research & Training Institute, Central Silk Board, Jorhat, Assam for this work.