Structure, Property, and Relaxation Behavior of Mulberry (Bombyx Mori) and Tasar (Antheraea Mylitta) Silk

ABSTRACT

Mechanical properties of fully degummed filaments of mulberry and tasar silk have been investigated and correlated with structure and morphology. The tensile behavior of mulberry silk filament was different from tasar, which demonstrated characteristic yield point, lower modulus, and breaking extension twice as high as that of mulberry. Stress relaxation and inverse relaxation/stress recovery were observed for both varieties of silk. The magnitude of inverse relaxation increases with the increase in peak tension and reduction in retraction also observed with the decrease in peak tension. Tensile properties and relaxation behavior were correlated with density, birefriengence, orientation index, and sonic modulus.

KEYWORDS:

• Mulberry
• tasar
• tenacity
• breaking extension
• inverse relaxation
• modulus