TY - JOUR
T1 - Non-equilibrium phase behavior of diblock copolymer melts and binary blends in the intermediate segregation regime
AU - Lipic, Paul M.
AU - Bates, Frank S.
AU - Matsen, Mark W.
PY - 1999/8/15
Y1 - 1999/8/15
N2 - The phase behavior of intermediately segregated (XN = 45) poly(ethylene)-poly(ethylethylene) (PE-PEE) diblock copolymers and PE-PEE binary blends are characterized using transmission electron microscopy and small-angle X-ray scattering. Surprisingly, the preparation-dependent, nonequilibrium phase behavior can be overwhelming even at this degree of segregation. A pure diblock with a poly(ethylene) volume fraction of fPE = 0.46 exhibited coexisting lamellae and perforated layers when prepared using a precipitation technique, but contained only the lamellar morphology when solvent cast. This preparation dependence was more dramatic in binary diblock copolymer blends with average compositions of 〈fPE〉 = 0.44, 0.46, and 0.48. Precipitated blends exhibited a microphase separated structure that was disordered and bicontinuous; however, solvent cast samples exhibited either a cylindrical, coexisting cylindrical and lamellar, or lamellar morphology. This nonequilibrium behavior is attributed to the high degree of segregation and the proximity to the cylinder/lamellae phase boundary.
AB - The phase behavior of intermediately segregated (XN = 45) poly(ethylene)-poly(ethylethylene) (PE-PEE) diblock copolymers and PE-PEE binary blends are characterized using transmission electron microscopy and small-angle X-ray scattering. Surprisingly, the preparation-dependent, nonequilibrium phase behavior can be overwhelming even at this degree of segregation. A pure diblock with a poly(ethylene) volume fraction of fPE = 0.46 exhibited coexisting lamellae and perforated layers when prepared using a precipitation technique, but contained only the lamellar morphology when solvent cast. This preparation dependence was more dramatic in binary diblock copolymer blends with average compositions of 〈fPE〉 = 0.44, 0.46, and 0.48. Precipitated blends exhibited a microphase separated structure that was disordered and bicontinuous; however, solvent cast samples exhibited either a cylindrical, coexisting cylindrical and lamellar, or lamellar morphology. This nonequilibrium behavior is attributed to the high degree of segregation and the proximity to the cylinder/lamellae phase boundary.
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U2 - 10.1002/(SICI)1099-0488(19990815)37:16<2229::AID-POLB25>3.0.CO;2-C
DO - 10.1002/(SICI)1099-0488(19990815)37:16<2229::AID-POLB25>3.0.CO;2-C
M3 - Article
AN - SCOPUS:0032592659
SN - 0887-6266
VL - 37
SP - 2229
EP - 2238
JO - Journal of Polymer Science, Part B: Polymer Physics
JF - Journal of Polymer Science, Part B: Polymer Physics
IS - 16
ER -