Unperturbed dimensions and the theta temperature of dextran in ethylene glycol solutions

Yükleniyor...
Küçük Resim

Tarih

2000

Dergi Başlığı

Dergi ISSN

Cilt Başlığı

Yayıncı

Pergamon-Elsevier Science Ltd

Erişim Hakkı

info:eu-repo/semantics/closedAccess

Özet

The unperturbed molecular dimensions of dextran samples (of different molecular weights) have been evaluated in ethylene glycol solutions from viscosity measurements at 25 degrees C, 30 degrees C, 35 degrees C, 40 degrees C and 45 degrees C. The unperturbed dimension, K-o, has been determined From extrapolation methods. i.e, Kurata-Stockmayer-Fixman (KSF), Berry and Inagaki Suzuki-Kurata (ISK) equations, The hydrodynamic expansion factor, alpha(eta), as well as the unperturbed root-mean-square end-to-end distance, [r(2)](o)(1/2), found for dextran samples in ethylene glycol solutions, indicated that the polymer coils are contracted as the temperature is raised From 25 degrees C to 45 degrees C. The long-range interaction parameter. B, was also evaluated and a significant decrease is found for the dextran/ethylene glycol system between 25 degrees C and 45 degrees C. The theta temperatures, Theta, were determined as 328.53, 328.02 and 325.93 K from the temperature dependence of the interaction parameter, respectively.

Açıklama

Anahtar Kelimeler

Dextran, Ethylene Glycol, Unperturbed Dimension, Theta Temperature

Kaynak

European Polymer Journal

WoS Q Değeri

Q2

Scopus Q Değeri

Cilt

36

Sayı

10

Künye