Liquid crystalline polymers containing heterocycloalkanediyl groups as mesogens, 1. Liquid crystalline polymethacrylates and polyacrylates containing 1,3‐dioxane‐2,5‐diyl groups as mesogens in the side chain

Polymethacrylates and polyacrylates containing 4‐[5‐(4‐methoxyphenyl)‐1,3‐dioxan‐2‐yl]‐phenol moieties as mesogenic units and an aliphatic spacer containing eleven methylene units were synthesized. Their phase behavior was studied by differential scanning calorimetry and optical polarizing microscopy, and compared with the phase behavior of the corresponding polymethacrylates and polyacrylates containing 4′‐methoxy‐4‐biphenylol as mesogens. All polymers present smectic mesomorphism. The substituted 2,5‐diphenyl‐1,3‐dioxane mesogen resembles a terphenyl mesogen in which the internal phenyl ring is hydrogenated. Even so, when compared with polymers containing biphenyl moieties, the glass transition temperatures of the polymers containing 1,3‐dioxane moieties are lower, although their isotropization occurs at higher temperatures.