Liquid crystalline side chain polymers consisting of acrylate and 2(S)-[2(S)-methylbutoxy]propionate

Abstract

Besides the usual acrylates, 4-[4-(n-acryloloxyalkyloxy)phenyl]benzoic acids (4a-4c), new acrylates containing two units of acrylic acid, 4-{4-[n-(3-acryloloxypropionyloxy)alkyloxy]phenyl}benzoic acid (5a-5c), are formed by the esterification of acrylic acid and 4-[4-(n-hydroxyalkyloxy)phenyl]benzoic acid (3). All the mesogenic monomers which were synthesized from the corresponding acrylates (4a-5c) and 4-hydroxyphenyl 2(S)-[2(S)-methylbutoxy]propionate (2) exhibit the enantiotropic S∗_c and S_A phases. The S∗ _c phase temperature range is up to 44°C. The range of spontaneous polarization and response time for those monomers is between 34 and 85nC cm-², and 55 and 460μs, respectively. Some liquid crystal side chain polymers containing 2 are switchable in the presence of an electric field. A spontaneous polarization of 72nC cm-² and a response time of 2.6 ms were the best results obtained for those polyacrylates.