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Comparison of the phase behaviour of the liquid‐crystalline polymer/poly(methyl methacrylate) and poly(vinyl acetate)/poly(methyl methacrylate) blends
Author(s) -
Nesterov Anatoly E,
Lipatov Yuri S.,
Horichko Vitaly V.
Publication year - 1999
Publication title -
polymer international
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.592
H-Index - 105
eISSN - 1097-0126
pISSN - 0959-8103
DOI - 10.1002/(sici)1097-0126(199902)48:2<117::aid-pi116>3.0.co;2-c
Subject(s) - materials science , vinyl acetate , methyl methacrylate , spinodal decomposition , polymer , lower critical solution temperature , polymer blend , poly(methyl methacrylate) , polymer chemistry , nucleation , phase (matter) , miscibility , amorphous solid , spinodal , cloud point , chemical engineering , composite material , copolymer , organic chemistry , chemistry , engineering , pulmonary surfactant
The phase behaviour of blends of a liquid‐crystalline polymer (LCP) and poly(methyl methacrylate) (PMMA), as well as the phase state of blends of PMMA and poly(vinyl acetate) (PVA) has been investigated using light scattering and phase‐contrast optical microscopy. The blends of LCP and PMMA have been obtained by coagulation from ternary solutions. The cloud point curves were determined. It was established that both pairs demix upon heating, ie have an LCST. In the region of intermediate composition, the phase separation proceeds according to a spinodal mechanism; however for LCP/PMMA blends, the decomposition proceeds according to a non‐linear regime from the very onset. In the region of small amounts of LCP, the phase separation follows a mechanism of nucleation and growth. For PMMA/PVA blends, the spinodal decomposition proceeds according to a linear regime, in spite of the molecular mobility that PVA chains develop at lower temperatures. Only after prolonged heat treatment does the process transit to a non‐linear regime. The data show a similarity between the phase behaviour of blends of liquid‐crystalline and of flexible amorphous polymers. The distinction consists of the absence of a linear regime of decomposition for LCP‐PMMA blends. © 1999 Society of Chemical Industry