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Evolution of phase morphology in compatibilized polymer blends at constant quench depths: Complementary studies by light scattering and transmission electron microscopy
Author(s) -
Jackson C. L.,
Sung L.,
Han C. C.
Publication year - 1997
Publication title -
polymer engineering and science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.503
H-Index - 111
eISSN - 1548-2634
pISSN - 0032-3888
DOI - 10.1002/pen.11792
Subject(s) - materials science , transmission electron microscopy , phase (matter) , ternary operation , copolymer , compatibilization , optical microscope , scattering , polystyrene , spinodal decomposition , polymer blend , phase boundary , light scattering , analytical chemistry (journal) , composite material , scanning electron microscope , polymer , optics , nanotechnology , chromatography , physics , organic chemistry , computer science , programming language , chemistry
The effect of added block copolymer on the phase separation and morphology evolution in a partially miscible blend of polystyrene and polybutadiene near the critical composition is studied by temperature jump light scattering (TJLS) and transmission electron microscopy (TEM). As block copolymer is added, the phase boundary is shifted to lower temperatures and the phase separation process is slowed dramatically. Since the quench depth greatly affects the rate of phase separation in any blend system, we have used equivalent quench depths by adjusting for the shift in the phase boundary as block copolymer is added. The morphology evolution of these ternary blends was studied by preparing TEM specimens at equivalent shallow quench depths (Δ T = 1.6°C) and allowing each blend mixture to coarsen for the time required to reach a specific constant size, or q ‐value, using the TJLS data on the kinetics of phase separation. The q ‐range selected was q ∼ 0.003–0.005 nm −1 , which corresponds to a spacing of 1–2 μm in real space. The combination of light scattering and microscopy techniques more rigorously describes the compatibilization process in these complex ternary systems.