学術雑誌論文

学術雑誌論文

text

Polymer. 2010, 51(18), p. 4243-4248

Solution properties of amylose tris(n-butylcarbamate). Helical and global conformation in alcohols

Elsevier BV

英語

text

2010-08

https://doi.org/10.1016/j.polymer.2010.06.048

Particle scattering functions P(k), z-average radii of gyration <S^2>_z^<1/2>, intrinsic viscosities [η], infrared absorption (IR) spectra, and specific rotations have been determined by light and/or small-angle X-ray scattering, viscometry, IR, and polarimetry for narrow distribution samples of amylose tris(n-butylcarbamate) (ATBC) ranging in weight-average molecular weight from 1.7 × 10^4 to 1.7 × 10^6 in 2-propanol at 35 °C, 1-propanol at 40 (or 35) °C, 2-ethoxyethanol at 25 °C, and 2-butanol at 45 °C. The two propanols are found to attain the theta state at 35 °C. The number fraction f1698 of intramolecular hydrogen bonds between the CO and NH groups of the ATBC chain is obtained from IR spectra, and the helix pitch h (or the contour length) per residue and the Kuhn segment length λ^<-1> are estimated to be 0.25-0.29 nm and 20-40 nm, respectively, from analyses of P(k), <S^2>_z, and [η] data on the basis of the wormlike chain. The relationship among the three parameters (f_<1698>, h, and λ^<-1>) in the four alcohols and that among the previous estimates in tetrahydrofuran-methanol mixtures are explained in a unified manner by a two-state model, in which each chain consists of semiflexible (loosely helical) and rodlike (rigid helical) sequences. Namely, h increases when intramolecular hydrogen bonds are broken. This differs from the case of amylose tris(phenylcarbamate) for which the bulkiness of polar solvent molecules extends the helix of the polymer.

25932

Solution properties of amylose tris(n-butylcarbamate). Helical and global conformation in alcohols

Elsevier BV

英語

2010-08

Polymer

51

18

4243

4248

https://doi.org/10.1016/j.polymer.2010.06.048

https://hdl.handle.net/11094/25932