Tussah silk

Tussah silk is derived from other insects. 

Tussah silk Antheraea pemyi Oak (Quercus) trees China... 

Tanaka, T., Magoshi, J., Magoshi, Y., Lotz, B., Inoue, S. I., Kobayashi, M., Tsuda, H., Becker, M. A., Han, Z., and Nakamura, S. (2001). Spherulites of Tussah silk fibroin. Structure, thermal properties and growth rates./. Therm. Anal. Calorimetry 64, 645-650. 

Tsukada, M., Freddi, G., Gotoh, Y., and Kasai, N. (1994). Physical and chemical-properties of tussah silk fibroin films. / Polym. Sri. B Polym. Phys. 32, 1407-1412. 

Marsh, R. E., Corey, R. B., and Pauling, L. (1955a). The structure of Tussah silk fibroin. 

Brilliance of hue this is especially important on mulberry silk. Many dyeings on tussah silk are much duller and the dyed silk shows a lower colour yield because of inferior exhaustion. 

When brought near to a flame, natural (ordinary and wild or tussah) silk bums with an odour of burnt hom and leaves a spongy carbonaceous residue (except with heavily weighted silk) artificial silks with a cellulose basis bum rapidly, almost without odour or residue, while " strengthened " 1 silks leave an ash in the form of the fibre artificial silks with a gelatine basis (A. Millar s silk, Vandura silk) bum like animal fibres. 

In this case the heating on the water-bath is prolonged to half an hour since, especially with fabrics containing either heavily weighted silk or wild (tussah) silk, the dissolution of this in potash takes place more slowly than with wool. 

Partly soluble tussah silk (wild), regenerated proteins, acetate, Amel. 

Soluble cultivated silk, tussah silk, hairs, wool, Darvan, Amel, acetate Dacron in 40 minutes Partly soluble Orion (Dynel and Saran melt). 

A detailed structure for Tussah silk fibroin has been derived which is in agreement with the X-ray diffraction data. The structure is similar to that of Bombyx mori fibroin in that it is based on anti-parallel-ohain pleated sheets the method of packing of the sheets, however, is quite different. 

It seems highly probable that the structure of the p (stretched) form of poly-L-alanine is essentially that derived for Tussah silk. 

Table 1. Composition of the fibroins of Bombyx mori and Tussah silks ...

Amino-acid Bombyx -mori Tussah silk... 

In the current investigation, a detailed structure for Tussah silk fibroin has been derived which is compatible with both chemical and X-ray data. This structure also has strong impUcations concerning the structure of the (stretched) form of XM>ly-i,-alanine. 

Samses of Tussah silk (Antherea pemyi) were kindly supplied by Prof. S. Mizushima of the University of Tokyo. For X-ray photography, degummed fibers (Schroeder Kay, 1956) were arranged in the form of a bundle about 0-5 mm. in diameter. Diffraction photographs were taken in an evacuated 3-cm.-radios camera and in a helium-filled lO-cm.-radius camera with nickel-filtered copper K(x radiation (A=1 6418 A). 

It was found that, within the limits of visual observation, the 400 reflection of NaF was exactly coincident with the center of the sixth-order meridional reflection of Tussah silk. The spacing of the 400 reflection of NaF, as measured on the Straumanis photographs, was 1 158 A. In confirmation of this spacing, the lattice parameter was obtained from a least-squares treatment of all of the observed powder lines it was found to be 4 6327 A with a probable error of 0 0003 A, in satisfactory agreement with the value 4 620 0 004 kX. (= 4 629 0 004 A) obtained by Davey (1923). Accordingly, the fiher-axis identity distance of Tussah silk is 6 949 A, with an estimated limit of error of about 0 010 A. 

Table 2. Spaeings and relative intenaitieg for equatorial reflections for Bombyx mori and Tussah silk fibroins...

Thus, the two identity distances which, in the case of Bombyx mori, have been shown to lie within the plane of the pleated sheets— the k-axis (fiber axis) identity distance, which represents the distance between alternate residues along the polypeptide chains, and the a-axis identity distance, which represents the distance between alternate polypeptide chains in the hydrogen-bonded sheet—appear to have close counterparts in Tussah silk. On the other hand, the methods of packing of the sheets, as represented by the OOZ reflections, axe apparently different in the two silks. 

With the aid of the Bombyx mori pattern, we have been able to index the diffraction pattern of Tussah silk on the basis of an orthogonal unit ceU with... 

Prof. R. BriU has called to our attention that the dimensions of this orthorhombic unit cell of Tussah silk are essentially equivalent to those proposed by... 

The formulation of the detailed structure of Tussah silk was arrived at by a consideration of the ways in which adjacent pleated sheets might pack together. The absence of odd orders of reflections of the type OOZ and the relatively high intensities of the 002 and 004 reflections indicate that the pleated sheets are spaced at approximately equal intervals of 5-3 A along the c axis the relative position of adjacent pleated sheets was determined by packing considerations. 

The pseudo unit of structure of Tussah silk is shown diagrammatically in Kg. 2 the positional parameters... 

Pig. 3. A paukiiig drawing of tho pseudo sbruotuio of Tussah silk ( ) viewed along the fiber axis, (6) viewed perpeadioulai to the fiber axis and parallel to the plane of the pleated sheets. 

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