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An investigation of the blend of partially brominated poly(2,6‐dimethyl 1,4‐phenylene oxide) and polystyrene in the primary (glass‐to‐rubber) transition region
Author(s) -
Choe Soonja,
Aklonis J. J.
Publication year - 1987
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.760271704
Subject(s) - diluent , materials science , glass transition , phenylene , polystyrene , polymer , relaxation (psychology) , solubility , natural rubber , intermolecular force , polymer chemistry , oxide , dilution , chemical engineering , thermodynamics , composite material , organic chemistry , chemistry , molecule , psychology , social psychology , physics , engineering , metallurgy
Abstract Compatible polymer blends can be used to test critically the viability of the damped Debye lattice (DDL) model of relaxation in the primary (glass‐to‐rubber) transition region. Since these blends form because of specific intermolecular interaction, the force constants that characterize intermolecular elastic interactions can be controlled to some extent by varying blend composition. The model predicts an unusual sharpening of the stress relaxation master curve of a marginally two‐dimensional DDL upon dilution with a plasticizer. We have prepared an appropriate two‐dimensional DDL by adding modest amounts of partially brominated poly(2,6‐dimethyl 1,4‐phenylene oxide) to polystyrene to form compatible blends. As predicted by the model, sharpening of the stress relaxation behavior upon dilution was observed for all blend compositions and for all diluents used. However, at higher brominated poly(phenylene oxide) concentrations, the anticipated diluent concentration dependence was not always observed and the sharpening of the stress relaxation behavior was less than expected. In similar experiments carried out on diluted homopolymers, the relative values of the solubility parameters of the polymers and the diluents strongly influenced the effectiveness of the diluent in changing the stress relaxation behavior. In this blend system, the particular chemical nature of the diluent was found to be much less important; in fact, the three diluents used all evoked approximately the same behavior despite their having solubility parameters that differed significantly.