Elastic moduli of multiblock copolymers in the lamellar phase
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Date
2004-02-22
Authors
Thompson, R. B.
Rasmussen, Kim
Lookman, T.
Journal Title
Journal ISSN
Volume Title
Publisher
AIP Publishing
Abstract
We study the linear elastic response of multiblock copolymer melts in the lamellar phase, where the
molecules are composed of tethered symmetric AB diblock copolymers. We use a self-consistent
field theory method, and introduce a real space approach to calculate the tensile and shear moduli
as a function of block number. The former is found to be in qualitative agreement with experiment.
We find that the increase in bridging fraction with block number, that follows the increase in
modulus, is not responsible for the increase in modulus. It is demonstrated that the change in
modulus is due to an increase in mixing of repulsive A and B monomers. Under extension, this
increase originates from a widening of the interface, and more molecules pulled free of the interface.
Under compression, only the second of these two processes acts to increase the modulus.
Description
Copyright (2004) AIP Publishing. This article may be downloaded for personal use only. Any other use requires prior permission of the author and AIP
Publishing.
The following article appeared in Journal of Chemical Physics 120 and may be found at http://dx.doi.org.proxy.lib.uwaterloo.ca/10.1063/1.1643899
Keywords
multiblock copolymers, self-consistent field theory, elastic moduli