Premium
Self‐assembly via a complex phase transition in mixtures of polystyrene‐ block ‐polybutadiene block copolymer and poly(methyl vinyl ether)
Author(s) -
Hashimoto Takeji,
Izumitani Tatsuo,
Oono Katsuaki
Publication year - 1995
Publication title -
macromolecular symposia
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.257
H-Index - 76
eISSN - 1521-3900
pISSN - 1022-1360
DOI - 10.1002/masy.19950980182
Subject(s) - polybutadiene , materials science , lipid microdomain , copolymer , spinodal decomposition , polystyrene , polymer chemistry , phase (matter) , polymer , glass transition , lamellar structure , transmission electron microscopy , crystallography , chemical engineering , membrane , composite material , chemistry , organic chemistry , nanotechnology , biochemistry , engineering
The self‐assembly of a binary mixture of polystyreneblock‐polybutadiene (SB) and poly(methyl vinyl ether) (PVME) was studied by transmission electron microscopy and time‐resolved light scattering. The self‐assembly studied involved first microphase separation, in which a microdomain structure composed of polybutadiene block chains (PB) was formed in a matrix composed of polystyrene block chains (PS) and PVME homopolymers, and subsequently macrophase separation of the PVME from the microdomain phase of SB. The microphase separation was induced in a film preparation process using a solution cast method at room temperature. The macrophase separation was induced by rapidly heating the film specimens to above a critical temperature where PVME and PS undergo spinodal decomposition (SD). This complex phase transition, involving microphase separation followed by macrophase separation, was found to generate a superlattice structure (or a modulated structure) with two characteristic spacings: A macro associated with the SD and A micro associated with the microphase separation, both being generally time‐dependent. The growth of the “macrodomains” was found to be pinned at A macro ˜ 840 nm due to the elastic effect of the microdomain structure. The microdomain structure with A micro ˜ 57 nm was found to undergo a morphological transition (a transition between two ordered phases of block copolymers) as a consequence of the local composition change of the two polymers induced by the SD.