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International Journal of Polymer Science
Volume 2011, Article ID 570149, 13 pages
http://dx.doi.org/10.1155/2011/570149
Research Article

Effect of Surfactants on Association Characteristics of Di- and Triblock Copolymers of Oxyethylene and Oxybutylene in Aqueous Solutions: Dilute Solution Phase Diagrams, SANS, and Viscosity Measurements at Different Temperatures

1Department of Chemistry, Sardar Patel University, Vallabh Vidyanagar 388 120, Gujarat, India
2Solid State Physics Division, Bhabha Atomic Research Center, Mumbai 400 085, India
3UGC-DAE Consortium for Scientific Research, Mumbai Center, Mumbai 400 085, India

Received 7 March 2011; Revised 29 June 2011; Accepted 7 July 2011

Academic Editor: Jan-Chan Huang

Copyright © 2011 Sanjay H. Punjabi et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

The interactions in poly(oxyethylene) (E) – poly(oxybutylene) (B) of EB or EBE type block copolymers-sodium dodoecyl sulfate (SDS) or dodecyltrimethylammonium bromide (DTAB) and/or t-octylphenoxy polyethoxyethanol, (TX-100) have been monitored as a function of surfactant concentration and temperature. The addition of ionic surfactants to copolymer micellar solutions in general induced not only shape transition from spherical to prolate ellipsoids at 30C in the copolymer micelles but also destabilize them and even suppress the micelle formation at high surfactant loading. DTAB destabilizes the copolymer micelles more than SDS. TX-100, being nonionic, however, forms stable mixed micelles. The block copolymer-surfactant complexes are hydrophilic in nature and are characterized by high turbid and cloud points. Triblock copolymer micelles got easily destabilized than the diblock copolymer ones, indicating the importance of the interaction between the hydrophilic E chains and surfactants. The effects of destabilization of the copolymer micelles are more dominating than the micellar growth at elevated temperatures, which is otherwise predominant in case of copolymer micelles alone.