The Tensile Properties of Cocoon Silk of the SpiderAraneus diadematus

Abstract

Spider silk has attracted considerable interest in the last 10 years, because it shows a unique combination of high strength, high elongation and extreme fineness. After a general overview about known tensile properties of the different types of spider silk, the tensile properties of Araneus diadematus cocoon silk are characterized based on experimental data of five different cocoons. It is shown that A. diadematus cocoon silk has a completely different stress-strain behavior in comparison with dragline silk of the same spider species. In the second part of the study, the elastic modulus, yield strength and visco-elastic hardening were examined to determine whether they can be controlled independently of each other. It is proved that the experimental stress-strain curves can be represented effectively by just four independent parameters. Moreover, the yield region is not independent of the hardening zone. Further research on the morphology and structure of cocoon and dragline threads will be required to understand the different stress-strain behavior of both fibers.