Highly ordered side-chain liquid-crystalline polymers from maleic anhydride and swallow-tailed 1-alkenes having two mesogens

Abstract

Side‐chain liquid‐crystalline polymers (SCLCPs) were synthesized from the alternating copolymerization of maleic anhydride with swallow‐tailed 1‐alkenes having two mesogens. In contrast to similar polymers from 1‐alkenes with one mesogen per repeating unit, these novel polymers exhibited lower isotropization temperatures and higher glass transition temperatures. The degree of order in the mesophase strongly increased: these SCLCPs exhibited a highly ordered smectic H phase. The polymers with a hexyl spacer between the malonate junction and the mesogen exhibited a uniaxially limited‐correlation‐length smectic E mesophase (SEu) which has, according to our knowledge, not been observed before. The highest transition temperatures and entropy changes were observed for polymers with completely interdigitated side chains.

Side-chain Liquid Crystal Polymers (SCLCP): Methods and Materials. An Overview

“…The polymers exhibited slightly wider, than monomers, mesophase temperature range (for example for p=4, m=6: Cr 115 SmH d 119 SmE d 133 I). Doubling the mesogen density results in a higher degree of order of the mesophase - polymers with double mesogen have a tendency to generate SmH, SmE and SmA mesophases, whereas analogous single-mesogen polymers exhibit SmB hex and SmA mesophases [ 98 , 99 ].…”