Liquid crystal dimers with organosilicon spacers as models for side chain LC polymers

摘要

A series of six mesogenic dimers were prepared containing terminal 4'-methoxyphenyl-4-octenyloxybenzoate groups, of the general formula [MeOC_6H_4O(O)CC_6H_4O(CH_2)_8SiMe_2]_2R, where R = -CH_2-,-(CH_2)_2-,-(CH_2)_3-,-SiMe_2-,-O- and -NH-. Their liquid crystal properties were compared with those of the structurally relevant side chain polymers with the same mesogenic moiety: polycarbosilanes, polyethylene, and polysiloxane. It is shown that the low molecular dimers can be used as models for evaluating and predicting mesogenic characteristics of macromolecular systems with backbones structurally equivalent to spacers of the dimers.