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Abstract
The synthesis and characterization of several mesomorphic copolymer sidechain siloxanes is presented and discussed from the standpoints of the extent of pendant substitution as well as composition. For a given copolymer, both the glass-mesomorphic and mesomorphic-isotropic transition temperatures were found to increase, although not linearly so, with increasing substitution up to ca. 70% extent of reaction (determined by FT-NMR and elemental analysis), beyond which, however, there was then little further change in either. In addition, the glass-mesomorphic transition temperature increased more slowly than that for the mesomorphic-isotropic transition as the copolymer composition was varied. The findings confirm the results reported some time ago that even partially-reacted poly(mesomorph-co-hydro)siloxanes can exhibit liquid-crystalline properties over extensive temperature ranges; as well as the contention that judicious adjustment of the makeup of sidechain siloxanes can provide a variety of materials that are useful both as gas- and liquid-chromatographic stationary phases.