Apparatus for Simultaneous Small Angle Neutron Scattering and Steady Shear Viscosity Studies of Polymer Melts and Solutions.
The design and construction of an apparatus for studying the simultaneous small angle neutron scattering (SANS) and steady shear viscosity behavior of polymer melts and concentrated solutions is discussed. Successful operation of the device is demonstrated on a blend of 20 weight percent deuterated polystyrene and 80 weight percent poly(vinylmethylether). The effects of shear on the critical behavior of the blend are observed in the SANS behavior as a function of temperature and shear rate and indicate shear induced mixing behavior for the range of shear rates examined. The steady shear viscosity results alone are insufficient for detecting the transition from one to two phases. The examination of shear effects in polymer blends is important for understanding the critical behavior of binary systems. Technologically, knowledge of the phase behavior of polymer blends under shear are important for the design and improvement of commercial blend processing.
National Institute of Standards and Technology, Gaithersburg, MD 20899.
Alan I
AI
Nakatani
National Institute of Standards and Technology, Gaithersburg, MD 20899.
Hongdoo
H
Kim
National Institute of Standards and Technology, Gaithersburg, MD 20899.
Charles C
CC
Han
deuterated polystyrene; phase separation; poly(vinylmethylether); polymer blends; small angle neutron scattering; viscosity