クモ糸の機械的性質

抄録

Threads from spiders may be one of the best structural materials produced by nature. They are used to capture and wrap insects. Less attension has been paid to their mechanical properties of spider silk in contrast to silk fibers made by silkworm. In this paper, the mechanical properties of dragline silk produced by Nephila Clavata called Jorougumo in Japanese are investigated. It is shown for the properties of the dragline that (1) the surface is featureless without any typical mark, (2) the dragline of diameter 2 to 5μm consists of the microfibres of diameter about 0.1μm, (3) the diameter is proportional to a square of the body length of spider, (4) the glass transition temperature of dragline from the spiders collected in July is lower than that in September and (5) the dragline which has the fracture stress of about 1500MPa and the fracture strain of about 0.3 is almost equivalent to the best man-made fibres such as aramid fibers.