Ordering of sphere forming SISO tetrablock terpolymers on a simple hexagonal lattice

Jingwen Zhang, Scott Sides, Frank S. Bates

Research output: Contribution to journalArticlepeer-review

Abstract

Hexagonally ordered spherical and cylindrical morphologies (P 6/mmm and P 6/mm space group symmetries) have been identified in bulk poly(styrene-b-isoprene-b-styrene-b-ethylene oxide) (SISO) tetrablock terpolymers. These materials were synthesized by adding up to 32% by volume O blocks to a parent hydroxy-terminated SIS triblock copolymer containing 40% S by volume, and the resulting morphologies were characterized by small-angle X-ray scattering, transmission electron microscopy, differential scanning calorimetry and dynamic mechanical spectroscopy. Disordered, spherical and cylindrical phases were documented with increasing O content, where both ordered states exhibit hexagonal symmetry. Theoretical calculations based on a numerical self-consistent field theory for polymers provide crucial insights into the molecular configurations associated with these morphologies. These results offer a new approach to independently control domain shape and packing in block copolymer melts through manipulation of the magnitude and sequencing of the binary segment-segment interactions (≪ SI ≤ ≪ SO Ξ ≪ IO), which dictate core segregation and the effective interdomain interactions.

Original languageEnglish (US)
Pages (from-to)256-265
Number of pages10
JournalMacromolecules
Volume45
Issue number1
DOIs
StatePublished - Jan 10 2012

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