Phase processes and energetics of spontaneous change in the dimensions of acetate fibers in nitromethane vapors
- Cite this article as:
- Shipovskaya, A.B., Shmakov, S.L. & Timofeeva, G.N. Polym. Sci. Ser. A (2006) 48: 509. doi:10.1134/S0965545X06050087
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The phenomenon of cyclic change (elongation and contraction) in the dimensions of acetate filaments and monofibers in the vapors of nitromethane as a specific solvent is quantitatively described. An algorithm for calculating the energy characteristics of the deformation, including the specific work, is developed. The longitudinal viscosity is estimated according to the deflection of a horizontally stretched sample. It is shown that the stereomeric structure of the polysaccharide is altered in the process of cyclic change in the filament dimensions, as is confirmed by reversal of the sign of specific optical rotation. The resultant data are interpreted in terms of phase (amorphous vitreous versus liquid-crystal states) and conformational transitions.