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Aqueous Gels of Triblock Copolymers of Ethylene Oxide and 1,2‐Butylene Oxide (Type BEB) Studied by Rheometry
Author(s) -
Kelarakis Antonis,
Havredaki Vasiliki,
Yuan XueFeng,
Chaibundit Chiraphon,
Booth Colin
Publication year - 2006
Publication title -
macromolecular chemistry and physics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.57
H-Index - 112
eISSN - 1521-3935
pISSN - 1022-1352
DOI - 10.1002/macp.200600028
Subject(s) - copolymer , ethylene oxide , micelle , aqueous solution , rheometry , oxide , materials science , dynamic mechanical analysis , polymer chemistry , rheology , dynamic modulus , modulus , viscosity , chemical engineering , chemistry , polymer , composite material , engineering , metallurgy
Summary: A triblock copolymer of ethylene oxide and 1,2‐butylene oxide with hydrophilic central block and hydrophobic end blocks, denoted B 10 E 227 B 10 , was prepared and characterised. The frequency dependence of dynamic modulus was determined for micellar solutions in the concentration range of 8–20 wt.‐% and the temperature range of 5–70 °C, and the fluid/gel diagram was established. The results were combined with those reported previously for copolymers B 12 E 227 B 12 and B 12 E 114 B 12 to obtain insight into the effect of B‐block and E‐block length on the rheological properties of systems of this type. The results are discussed in terms of micelles forming bridged networks and, at higher concentrations, packing in structured gels.Temperature dependence of the logarithm of storage modulus for aqueous solutions of copolymer B 10 E 227 B 10 at the concentrations (wt.‐%) indicated. Conditions: f = 1 Hz, A ≈ 0.5%.