Premium
Steady viscosity of a polymer/liquid crystal biphasic system
Author(s) -
Yang IKuan,
Lai Wei Yuan
Publication year - 2004
Publication title -
journal of applied polymer science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.575
H-Index - 166
eISSN - 1097-4628
pISSN - 0021-8995
DOI - 10.1002/app.13624
Subject(s) - materials science , viscosity , liquid crystal , reduced viscosity , polymer , acrylate , volume fraction , shear rate , molar mass , viscoelasticity , apparent viscosity , emulsion , composite material , polymer chemistry , chemistry , organic chemistry , monomer , optoelectronics
Steady shear viscosities of blends of poly(butyl acrylate) and cholesteryl oleyl carbonate were studied under a cone and plate fixture. Unique shear behavior was observed for the polymer/low molar mass liquid crystal mixture. The viscosity of the liquid crystal‐rich phase increases with polymer content until a maximum is reached. The height of the viscosity maximum decreases with the magnitude of the shear stress and disappears when the stress reaches 200 Pa. Addition of liquid crystal to the polymer‐rich phase causes a viscosity reduction, and at higher stress levels, the viscosity reduction becomes more effective with the same amount of liquid crystal addition. The viscosity reduction may be related to the fibril morphology of the liquid crystal and the viscosity maximum can be interpreted by the emulsion effect being counteracted by a viscosity reduction effect. A shear‐thickening behavior was observed in the intermediate shear rates for the blends with a volume fraction of poly(butyl acrylate) between 9.4 and 49.8%. This is a novel liquid–liquid system that exhibits a shear thickening behavior. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 92: 25–30, 2004