Effect of Ethanol on the Rheological Properties of Water-Rich Gels of Diblock Copolymer E43B11

✍ Scribed by Antonis Kelarakis; Vasiliki Havredaki; Colin Booth

• Publisher: John Wiley and Sons
• Year: 2004
• Tongue: English
• Weight: 411 KB
• Volume: 205
• Category: Article
• ISSN: 1022-1352
• DOI: 10.1002/macp.200400097

✦ Synopsis

Abstract

Summary: The effect of added ethanol on the rheological behaviour of aqueous solutions of diblock copolymer E~43~B~11~ (E = oxyethylene unit, B = oxybutylene unit) has been investigated. Thermally reversible sol‐gel transitions were observed for concentrated solutions of the copolymer in solutions containing 0–30 wt.‐% ethanol. Storage (G′) and loss (G″) moduli and yield stress (σ~y~) were used to define hard and soft gel phases. The introduction of 10 wt.‐% ethanol did not alter the phase behaviour greatly, whereas higher ethanol concentrations had a large effect, which differed in kind from that reported for triblock copolymers of ethylene oxide and propylene oxide, type EPE.

Temperature dependence of the logarithm of (•) storage and (○) loss modulus for 20 wt.‐% copolymer in 10 wt.‐% ethanol.

magnified imageTemperature dependence of the logarithm of (•) storage and (○) loss modulus for 20 wt.‐% copolymer in 10 wt.‐% ethanol.