延伸絹フィブロインの粘弾性にかんする研究
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概要
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The dynamic mechanical and thermal properties of drawn silk fibroin have been investigated. The conformation of silk fibroin treated by methanol or other organic polar solvents is known as β-form, while that of untreated and undrawn specimens is known as α-form. The latter can be transformed to β-form by mechanical drawing. The dynamic moduli (E') of untreated silk fibroin specimens drawn in the draw ratio of 1, 2 and 10 were 7.5×10^9, 2.5×10^<10> and 1.5×10^<11>dyne/cm^2 at 30℃, respectively, whereas those of the methanol-treated specimens were 1.6×10^<10>, 3.5×10^<10> and 2.0×10^<11> dyne/cm^2, respectively. The temperature dependence of dynamic modulus was determined. Below 100℃, the modulus decreased with increasing temperature, which is considered due to the water evaporation in the specimen. Above 160℃, the modulus still decreased but more slowly, which is caused by the molecular motion of main chain or a partial decomposition of silk fibroin. The tan δcurve showed the evaporation of water at temperatures below 100℃ for the drawn specimens and the relaxation of the main chain at around 240℃ for the well-oriented β-form specimens. The peak due to the relaxation of the main chain was observed at around 230℃ and 240℃ for α-and β-forms, respectively. There were two endothermic peaks in DTA curves : One is due to the evaporation of water at the temperature around 100℃ and the other at 270℃ for the undrawn α-form specimen and 290℃ for the undrawn β-form specimen. The decomposition peak appeared at about 320℃ for well-oriented specimens.
- 社団法人日本材料学会の論文
- 1973-05-15