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

Abstract

Summary: The effect of added ethanol on the rheological behaviour of aqueous solutions of diblock copolymer E43B11 (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 (σy) 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.

Effect of ethanol on the gelation of aqueous solutions of Pluronic F127

“…Near to the hard gel boundary, the soft gel has been recognized as a defective version of the hard gel, i.e. [26]. Our observation of different SAXS profiles for the two soft gels, that of 25 wt.% F127 at 50°C being characteristic of a disordered system and that of 30 wt.% F127 at 25°C being characteristic of an ordered system, is to be understood against this background.…”

Poly(ethylene oxide)–poly(styrene oxide)–poly(ethylene oxide) copolymers: Micellization, drug solubilization, and gelling features

“…S3d). Viscous fluids of the present type have been previously identified in aqueous micellar solutions of a wide range of block copolymers, including PEO-PPO [18,[47][48][49][50] and other PEO-PSO block copolymers [21,24,51]. In addition, G 0 and G 00 increased in about three magnitude orders at ca.…”

Effect of Ethanol on the Micellization and Gelation of Pluronic P123

“…We use the notation E = oxyethylene, OCH 2 CH 2 , P = oxypropylene, OCH 2 CH(CH 3 ), and subscripts m and n to denote number-average block lengths in repeat units. Several publications describe the effect on micellization and gelation of incorporating ethanol into aqueous solutions of these − and related , copolymers. In this paper we focus on one copolymer: E 21 P 67 E 21 (Pluronic notation P123).…”