Elastic moduli of multiblock copolymers in the lamellar phase
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.
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Cite this version of the work
R. B. Thompson, Kim Rasmussen, T. Lookman
(2004).
Elastic moduli of multiblock copolymers in the lamellar phase. UWSpace.
http://hdl.handle.net/10012/10302
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