In: Recent Developments in Silicone-Based Materials ISBN 978-1-61668-624-6
Editor: Maria Cazacu, pp. 33-75 © 2010 Nova Science Publishers, Inc.
Chapter 2
SOLUTION BEHAVIOR OF POLYSILOXANES
Maria Bercea, Simona Morariu, Cristina-Eliza Brunchi and Maria Cazacu
Petru Poni Institute of Macromolecular Chemistry, 41-A Grigore Ghica Vodǎ Alley,
700487 Iaşi, Romania
ABSTRACT
The thermodynamics of flexible polymers in solution have attracted the interest of
many investigators. Because of its unique properties (low viscosity even at high
molecular weight, high solubility in non-polar solvents, high volatility at low molecular
weight, low surface tension, high refractive index, etc.), poly(dimethylsiloxane) has been
the subject of various studies with respect to its solution properties. Several theories have
been put forward in an effort to explain the various phenomena occurring when very
flexible polymer molecules are dissolved in solvents of different qualities.
The aim of this chapter is to review briefly the background of thermodynamic and
rheological properties for different polysiloxanes in solution and to provide the recent
achievements in this area. The applicability of the theories explaining the various
phenomena that occur when very flexible polymer molecules are dissolved in solvents of
different qualities was critically discussed for the particular case of the polysiloxanes.
The extension of the Flory-Huggins theory by using the new concept of dimensional
relaxation developed recently by Wolf [1,2] enables the modeling of several hitherto
unexplainable anomalous phenomena, as for example the uncommon molecular weight
dependencies of second virial coefficient of poly(dimethylsiloxane) in dilute solutions
[3]. Rheological and optical properties of solutions of polysiloxanes can be regarded in
correlations with their interest for practical applications.
LIST OF SYMBOLS
AP-PDMS -bis(3-aminopropyl)-poly(dimethylsiloxane)
H
3
C-PDMS -bis(trimethylsilyl)-poly(dimethylsiloxane)
H-PDMS -bis(H)-poly(dimethylsiloxane)