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

被引：13

作者：

Çatiker, E

Güner, A ^{[1
]}

机构：

[1] Hacettepe Univ, Fac Sci, Dept Chem, TR-06532 Ankara, Turkey

[2] Abant Izzet Baysal Univ, Fac Sci, Dept Chem, TR-14280 Bolu, Turkey

来源：

EUROPEAN POLYMER JOURNAL | 2000年 / 36卷 / 10期

关键词：

dextran; ethylene glycol; unperturbed dimension; theta temperature;

D O I：

10.1016/S0014-3057(99)00299-2

中图分类号：

O63 [高分子化学（高聚物）];

学科分类号：

070305 ; 080501 ; 081704 ;

摘要：

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. (C) 2000 Elsevier Science Ltd. All rights reserved.

引用

页码：2143 / 2146

页数：4

共 15 条

[1] THE UNPERTURBED MOLECULAR DIMENSIONS OF POLY(ETHYLENE OXIDE) IN AQUEOUS-SOLUTIONS FROM INTRINSIC-VISCOSITY MEASUREMENTS AND THE EVALUATION OF THE THETA TEMPERATURE [J].