Helical Sense and Twisting Power in Thermotropic Side–Chain Copolymers

Abstract

ABSTRACTThermotropic chiral nematic copolymers containing (S)–(–)–1–phenylethyl alcohol and (R)–(–)–methyl mandelate with methacrylate backbone and those containing (S)–(–)–1–phenylethylamine and cholesterol with acrylate/methacrylate mixed backbone structures have been synthesized and characterized. It is found that the helical sense is dictated by chiral/nematic molecular interactions of a steric nature, and that the helical twisting power (HTP) is favored by the structural similarity between the chiral and nematic components. Furthermore, it is shown that HTP can be optimized with a suitable nematogenic comonomer by regulating the backbone flexibility within the acrylate/methacrylate series, which facilitates supramolecular arrangement without affecting the HTP.