Aqueous solution properties of oligo- and poly(ethylene oxide) by static light scattering and intrinsic viscosity

✍ Scribed by Seigou Kawaguchi; Genji Imai; Junto Suzuki; Akira Miyahara; Toshiaki Kitano; Koichi Ito

• Publisher: Elsevier Science
• Year: 1997
• Tongue: English
• Weight: 655 KB
• Volume: 38
• Category: Article
• ISSN: 0032-3861
• DOI: 10.1016/s0032-3861(96)00859-2

✦ Synopsis

Conformational properties of ethylene glycol, oligo-, and poly(ethylene oxide) ranging in weight-average molecular weight (Mw) from 62 to 1.1 × l07 have been studied by static light scattering and viscometry in salt-free and 0.45 M K2SO 4 water and in benzene. Above Mw = 6 × 103, intrinsic viscosity (It/I) and z-2 o 4 0 679 average square radius of gyration ((S)z) of PEO in a salt-free solution at 25 C, [7] = 4.33 × 10 Mw 1 2 18 1 16 2 o dl g-and (S)-= 4.08 x 10-Mw cm , respectively. The second virial coefficient is positive in water at 25 C but one order of magnitude smaller than reported by Devanand et al. (Macromolecules , 1991, 24, 5943). A 0-temperature for PEO in 0.45MK2SO 4 aqueous solution is determined to be 34.5°C and above Mw =4 x 102, [rl] and ($2), follow the power laws for an unperturbed polymer chain. The characteristic ratio (Coo) of PEO is 5.2 +'0.1.9.3 ,~ was determined for the persistence length and 8.7 ~,-1 for the molar mass per unit contour length of a PEO chain, based on the helical wormlike touched-bead model. The PEO chain in water behaves as a flexible polymer with a relatively large hydrodynamic diameter (9 A) because of the hydration of the PEO chain.