Copolymers derived from polyepichlorohydrin (PECH), bearing pendant mesogenic units are obtained by chemical modification of atactic samples of PECH with sodium 4-cyano-4'-biphenoxide. Rate and yield of substitution are strongly dependent on the molecular weight of the used PECH. A substantial rise (AT -110 "C) of glass transition temperature with the percentage of incorporated cyanobiphenyl groups is observed. Copolymers with an amount of substitution higher than 60% present thermotropic liquid-crystalline behaviour and form nematic phases. Chemical modification of PECH offers a simple method for the synthesis of new liquid-crystalline polyethers whose transition temperatures can be adjusted by varying the amount of substitution. 0 1992, Hiithig & Wepf Verlag, Basel CCC 0025-1 16X/92/$05.00

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