X-ray investigations on some liquid crystalline methacrylic polymers with ω-hexyloxysalicylaldimine side groups carrying p-alkyl or p-alkyloxy terminal substituents

Abstract

X-ray diffraction data for four different liquid crystalline side group methacrylic polymers based on the ω-hexyloxysalicylaldimine moiety with p-alkyl or p-alkyloxy terminal substituents are presented. For the decyloxy, dodecyloxy and octyl derivatives, a smectic C2 phase occurs over a broad temperature range, while for the tetradecyl derivative a complex behaviour was observed on cooling from the isotropic state. In this last case a smectic Ad phase arises, changing to a smectic C2 phase and a further smectic Cd phase. A possible explanation for the observed phenomena is presented.