Physical properties and structure of silk. XI. Glass transition temperature of wild silk fibroins

Abstract

Silk filament is spun by domestic silkworm, Bombyx mori. Wild silkworms also produce the same type of fibrous proteins, fibroins, which are practically used for silk gut or spinning yarn. Previously, we have reported the glass transition temperatures of fibroins obtained from domestic silkworm1.2 and tussah silkworm, (Antheraeapernyi),3 a wild silkworm. In the present study, we used three wilk silkworms, i.e., kususan (Dictyoplocu jupnzcu), erisan (A ttucus ricini), and tensan (Antherueu yumamui), and determined the glass transition temperatures of their fibroins by differential scanning calorimetry (DSC) and compared with that of domestic silk fibroin. The effects of methanol treatment on the glass transition temperatures were also investigated.