PHYSICAL AND CHEMICAL-PROPERTIES OF TUSSAH SILK FIBROIN FILMS

Physical and chemical structure, as well as thermal behavior of soluti on-cast regenerated films, prepared from tussah (Antheraea pernyi) sil k fibroin, were compared with those of solution-cast native films, in order to ascertain whether treatment (degumming, dissolution) used for preparation affected their properties. Regenerated fibroin films exhi bited a higher thermal stability than native ones, as shown by differe ntial scanning calorimetry, thermomechanical analysis, and dynamic mec hanical behavior. Glass transition temperature and other relevant ther mal transitions of the regenerated silk specimen shifted to higher tem peratures compared with those of native specimen. Molecular conformati on and crystalline structure did not show significant differences betw een the two kinds of silk films. Amino acid composition and molecular weight, however, distribution changed markedly after dissolving tussah silk fibroin fiber in concentrated LiSCN in polypeptide size was the main features for the regenerated silk fibroin. (C) 1994 John ch & Son s, Inc.