Morphologies of strongly-segregated polystyrene - polydimethylsiloxane diblock copolymers
Five polystyrene-polydimethylsiloxane (PS/PDMS) diblocks were synthesized by sequential anionic polymerization, and their morphologies characterized by small-angle x-ray scattering (SAXS) and transmission electron microscopy (TEM). All materials are microphase-separated in toluene-cast films, and estimates of the interaction parameter {chi} indicate that these materials are all strongly segregated. The strength of segregation is confirmed by differential scanning calorimetry, which indicates that the glass transition temperature of the PDMS phase is independent of molecular weight and composition, and essentially identical to that of PDMS homopolymer. The experimentally-determined phase diagram is strongly skewed towards low styrene volume fractions, even more than the styrene-isoprene (SI) diblock phase diagram, even though little conformational asymmetry should exist in the PS/PDMS system. The PS/PDMS diblocks form substantially larger microdomain structures than analogous SI diblocks reflecting the stronger segregation strength.
- OSTI ID:
- 215155
- Report Number(s):
- CONF-950801-; TRN: 96:000922-0676
- Resource Relation:
- Conference: 210. national meeting of the American Chemical Society (ACS), Chicago, IL (United States), 20-25 Aug 1995; Other Information: PBD: 1995; Related Information: Is Part Of 210th ACS national meeting. Part 1 and 2; PB: 1866 p.
- Country of Publication:
- United States
- Language:
- English
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