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Blends of some non‐flexible and flexible polymers: Routes to molecular composites?
Author(s) -
Cowie John M. G.,
Nakata Shoichi,
Adams Gordon W.
Publication year - 1996
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.19961120129
Subject(s) - miscibility , materials science , polymer , polymer blend , glass transition , polymer chemistry , vinyl acetate , composite material , hydrogen bond , vinyl alcohol , copolymer , mixing (physics) , phase (matter) , molecule , organic chemistry , chemistry , physics , quantum mechanics
The definition of a molecular composite is a blend of a rigid rod polymer and a flexible coil polymer that is miscible at the molecular level. This concept has been tested using systems in which the chain flexibilities differ as widely as possible as judged by the difference in glass transition temperatures (δTg). The biggest variation (δT ∼360°C) was obtained by mixing poly benzimidazole with copolymers of poly(vinyl acetate‐ran‐vinyl alcohol). It was observed that the blends were distinctly two phase when the hydroxyl content was less than 50 mol %. Above this value clear blends were obtained with finely dispersed phases although it is doubtful if mixing at the molecular level takes place. Miscible blends could be obtained from combinations of the sodium salt of poly(phenylene terephthalamide) with poly(4‐vinylpyridine) and mixtures of poly(phenyl imino‐1,4‐phenyleneoxyterephthalate) with poly(styrene‐stat‐hydroxylstyrene) where coulombic interactions and hydrogen bonding respectively promoted the miscibility.