Liquid crystal polymers. 20. Poly(1,4‐cycloalkylhydroquinone terephthalates) with flexible hexamethylene spacers in the main chain

A series of cycloalkylhydroquinone terephthalate copolyesters containing varying amounts of 1,6‐hexanediol flexible spacers were prepared by a two‐step reaction procedure and characterized for their liquid crystalline properties. Included in the series were hydroquinone monomers containing norbornyl, cyclohexyl, cycloheptyl, and cyclooctyl substituents. The norbornylhydroquinone series formed nematic melts at 1,6‐hexanediol contents of 30 mol‐% or less, but not at 40 mol‐%. The glass temperatures and melting points were higher than expected in the norbornylhydroquinone series, but analysis of dyad contents by 13C‐NMR indicated that the comonomers were randomly distributed.