Elastic moduli of multiblock copolymers in the lamellar phase.
PMID 15268564 · The Journal of chemical physics · 2004 · DOI 10.1063/1.1643899
Authors: R B Thompson; K Ø Rasmussen; T Lookman
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.
Cite
R B Thompson; K Ø Rasmussen; T Lookman. Elastic moduli of multiblock copolymers in the lamellar phase. The Journal of chemical physics (2004). PMID 15268564. DOI 10.1063/1.1643899.