التفاصيل البيبلوغرافية
| العنوان: |
Flow birefringence and optical anisotropy of poly( N-vinylpyrrolidone) molecules. |
| المؤلفون: |
Kononov, A.1 alexei.kononov@pobox.spbu.ru, Sibileva, M.1, Mikhailova, N.1, Grishchenko, A.1 |
| المصدر: |
Polymer Science -- Series A. Apr2013, Vol. 55 Issue 4, p213-217. 5p. |
| مصطلحات موضوعية: |
*FLOW birefringence, *ANISOTROPY, *MOLECULES, *BENZYL alcohol, *WATER, *AQUEOUS solutions |
| مستخلص: |
Concentration dependences of flow birefringence and viscosity of poly( N-vinylpyrrolidone) solutions in water and benzyl alcohol are investigated. The intrinsic anisotropy for a poly( N-vinylpyrrolidone) macromolecular segment, (α − α) = −(82 ± 8) × 10 cm, is determined from the results of birefringence measurements in benzyl alcohol. For aqueous solutions, a strong concentration dependence of the specific anisotropy of solution is obtained, a result that may be explained by the heterogeneity of coils. A model allowing for this heterogeneity is suggested. It makes it possible to fit the concentration dependence to a hyperbolic function, to separate contributions of heterogeneity anisotropy and form anisotropy to the birefringence of a solution, and to estimate the segment asymmetry parameter as p = 3.0 ± 0.5. [ABSTRACT FROM AUTHOR] |
| قاعدة البيانات: |
Academic Search Index |
