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Fractionation of a diblock copolymer in a demixing‐solvent system
Author(s) -
Podes̆va Jir̆í,
Stejskal Jaroslav,
Kratochvíl Pavel
Publication year - 1993
Publication title -
journal of applied polymer science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.575
H-Index - 166
eISSN - 1097-4628
pISSN - 0021-8995
DOI - 10.1002/app.1993.070490716
Subject(s) - copolymer , solvent , molar mass , methylcyclohexane , polymer chemistry , styrene , materials science , fractionation , phase (matter) , isoprene , chemical engineering , chemistry , organic chemistry , polymer , toluene , composite material , engineering
Phase behavior of a hydrogenated styrene/isoprene diblock copolymer in a dimethylformamide/methylcyclohexane demixing‐solvent pair has been studied. At a fixed copolymer concentration (1% w/v), the scheme of phase behavior (temperature vs. mixed‐solvent composition) of the system has been found to be complex, with several areas where various supramolecular structures are spontaneously formed. In a particular area of the scheme, a multistep demixing‐solvent fractionation of the copolymer has been performed. The resulting fractions have been characterized and the data used to construct integral distribution functions of copolymer molar mass and copolymer composition. These functions have been compared with those obtained by a previously reported light‐scattering characterization of the whole, unfractionated, nonhydrogenated precursor of the copolymer © 1993 John Wiley & Sons, Inc.