Tensile Property And Morphology Of Differently Degummed Silkworm(Bombyx Mori) Cocoon Silk Fibers And The Cocoon Silk Fibers From Transgenic Silkworm (Bombyx Mori) With Synthetic MaSpI Gene

Tensile tests have been performed on silkworm cocoon silk fibers degummed by five different methods: distilled water, borate buffer, sodium carbonate, urea and succinic acid. With an electronic single-fibre tensile instron, the force-displacement curves were obtained for each condition. The degumming Effects on silk include the decrease of the initial elastic modulus and the decrease of the proportional limit (i.e. yield point). These results suggest that the degumming process weaken at least one type of non-covalent interaction of core fibrion, such as hydrogen bonds and Van der waal's bonds, thus increase the spread of failure strengths.The stress-strain curve determined from the force-displacement curve as rescaled by the corresponding sample cross-sectional area failed to reproduce the shape of the original curves. The two important factors associated with the degumming could affect the tensile properties of silkworm silk: 1) the molecular change in the microstructure of two core fibroin, including inter- and/or intra-molecular structure changes, and 2) the degumming ratio.SEM was used to observe visually the silk morphology of differently degummed cocoon silk fibres. The effect of different degumming treatments on the tensile behavior, mechanical properties, and morphology of cocoon silk are clearly visible.Mechanical tests were performed on single brins of silkworm (Bombyx Mori) cocoon silk, to obtain the force-displacement curves. The results indicate that excepting the change from helices structures and random ciols to β-sheet strcutures,...