TY - JOUR
T1 - Phase behavior of an ABC triblock copolymer blended with A and C homopolymers
AU - Sugiyama, Masaaki
AU - Shefelbine, Terri A.
AU - Vigild, Martin E.
AU - Bates, Frank S.
PY - 2001/12/20
Y1 - 2001/12/20
N2 - The structures of ternary blends composed of a nearly symmetric poly(styrene-b-isoprene-b-dimethylsiloxane) (SID) triblock copolymer (volume fractions of S/I/D = 0.20/0.59/0.21, Mn = 40 000 g/mol) and equal volume fractions of low-molecular-weight polystyrene (Mn = 2360 g/mol) and poly(dimethylsiloxane) (Mn = 2200 g/mol) are investigated by small-angle X-ray and neutron scattering and transmission electron microscopy. When the total homopolymer volume fraction exceeds 65%, the blend macroscopically separates into ordered homopolymer-poor and -rich regions. Between 45 and 65% homopolymer volume fraction, hexagonally packed core-shell cylinders form with PDMS cores and PI shells. Between 15 and 45% homopolymer volume fraction, a core-shell gyroid morphology is observed with PDMS cores and PI shells. These core-shell variations of the classical structures of diblock copolymers are attributed to a small asymmetry in segment-segment interaction parameters. The neat SID block copolymer has a new complex ordered microstructure.
AB - The structures of ternary blends composed of a nearly symmetric poly(styrene-b-isoprene-b-dimethylsiloxane) (SID) triblock copolymer (volume fractions of S/I/D = 0.20/0.59/0.21, Mn = 40 000 g/mol) and equal volume fractions of low-molecular-weight polystyrene (Mn = 2360 g/mol) and poly(dimethylsiloxane) (Mn = 2200 g/mol) are investigated by small-angle X-ray and neutron scattering and transmission electron microscopy. When the total homopolymer volume fraction exceeds 65%, the blend macroscopically separates into ordered homopolymer-poor and -rich regions. Between 45 and 65% homopolymer volume fraction, hexagonally packed core-shell cylinders form with PDMS cores and PI shells. Between 15 and 45% homopolymer volume fraction, a core-shell gyroid morphology is observed with PDMS cores and PI shells. These core-shell variations of the classical structures of diblock copolymers are attributed to a small asymmetry in segment-segment interaction parameters. The neat SID block copolymer has a new complex ordered microstructure.
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U2 - 10.1021/jp011959r
DO - 10.1021/jp011959r
M3 - Article
AN - SCOPUS:0035924830
SN - 1089-5647
VL - 105
SP - 12448
EP - 12460
JO - Journal of Physical Chemistry B
JF - Journal of Physical Chemistry B
IS - 50
ER -