Inverted cylindrical microdomains by blending star-shaped and linear block copolymers
발표자
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초록
내용
We investigated the morphology formed in the binary blend of six-arm star shaped (poly(methyl methacrylate)-block-polystyrene)6 copolymer [(PMMA-b-PS)6] and PMMA-b-PS linear diblock copolymer. When the molecular weight of PMMA-b-PS is much larger (＞ ~ 4 ) than that of one arm of (PMMA-b-PS)6, PMMA-cylindrical microdomains are formed even though the volume fraction of PMMA (fPMMA) in both (PMMA-b-PS)6 and PMMA-b-PS is nearly symmetric (fPMMA ~0.5). Very interestingly, we found that even for a binary blend with the overall volume fraction of the PMMA block as large as 0.71, the major PMMA blocks still aggregate into cylindrical microdomains, thus, “inverted cylinders” are formed, although PS-cylinders are observed in the neat (PMMA-b-PS)6 and PMMA-b-PS melts. The experimental results as well as the formation of the inverted cylinders have been verified by self-consistent field theory (SCFT).