ISSN:
0021-8995
Keywords:
Chemistry
;
Polymer and Materials Science
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
,
Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
,
Physics
Notes:
Chemical composition and physical properties of silk fibers from Gonometa rufobrunnae, a silkworm belonging to the family Lasiocampidae (order Lepidoptera, class Insecta) have been studied. G. rufobrunnae silk fibroin contains a large amount of glycine and alanine, as well as hydroxyl, acidic, and basic amino acids. The gly/ala ratio is 1.5, similar to that of Bombyx mori silk fibroin. The ratio between polar and nonpolar amino acids is higher than that of either domestic (family Bombycidae) or wild (family Saturniidae) silk fibroins. The sericin is characterized by a large amount of hydroxyl amino acids, mainly serine. The infrared spectrum of G. rufobrunnae silk fibroin showed characteristic absorptions at 1630, 1530, and 700 cm-1 attributed to the β structure and at 1650 and 1540 cm-1 due to the random-coil conformation. The birefringence and isotropic refractive index values were 0.027 and 1.559, respectively. The differential scanning calorimetry (DSC) curve showed two minor endothermic peaks at 222 and 288°C, together with a major endothermic peak at 344°C, attributed to the decomposition of the fibroin with β conformation. The fibers exhibited a maximum contraction peak (4.3%) at about 230°C. The dynamic storage modulus (E′) exhibited an abrupt drop at 190°C, while the loss modulus (E″) curve increased above 185°C with a sharp slope. The surface of degummed G. rufobrunnae silk fibers was very smooth. The shape of the cross section was triangular, round, or roundish shaped. Some fibers were very flat, showing a ribbonlike shape. © 1993 John Wiley & Sons, Inc.
Additional Material:
5 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/app.1993.070480110
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