摘要：

A series of copolyesters 2 containing both linear mesogenic and non-linear non-mesogenic aromatic ester units was prepared and characterized for the ability of the latter to either modify or destabilize the liquid-crystalline (LC) properties of the former. The mesogenic units were formed from the reaction of 1,4-phenylene diacetate ( 3 ) with 4,4′-decamethylenedioxydibenzoic acid ( 5 ), whereas the non-mesogenic units were formed from reaction of the latter monomer with the diacetate of the non-linear biphenol, sulfonylbis(1,4′-phenylene) diacetate ( 4 ). The presence of the flexible spacer in each unit allows the copolyesters to form a nematic phase even at a content of non-mesogenic units as high as approximately 80 mole-%. Copolyester compositions with mesogenic unit contents approaching this limit for LC behavior appear to form melts which contain both nematic and isotropic phases below the isotropization transitions.

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