Highly asymmetric phase diagram of a poly(1,2-octylene oxide)-poly(ethylene oxide) diblock copolymer system comprising a brush-like poly(1,2-octylene oxide) block

Hamley, I. ORCID: https://orcid.org/0000-0002-4549-0926, O'Driscoll, B., Lotze, G., Moulton, C., Allgaier, J. and Frielinghaus, H. (2009) Highly asymmetric phase diagram of a poly(1,2-octylene oxide)-poly(ethylene oxide) diblock copolymer system comprising a brush-like poly(1,2-octylene oxide) block. Macromolecular Rapid Communications, 30 (24). pp. 2141-2146. ISSN 1521-3927 doi: 10.1002/marc.200900474

Abstract/Summary

The phase diagram of a series of poly(1,2-octylene oxide)-poly(ethylene oxide) (POO-PEO) diblock copolymers is determined by small-angle X-ray scattering. The Flory-Huggins interaction parameter was measured by small-angle neutron scattering. The phase diagram is highly asymmetric due to large conformational asymmetry that results from the hexyl side chains in the POO block. Non-lamellar phases (hexagonal and gyroid) are observed near f(PEO) = 0.5, and the lamellar phase is observed for f(PEO) >= 0.5.