Cholesteric polymeric networks with steroids as chiral components

Abstract

Induced cholesteric polymeric networks with steroids as chiral components were prepared with the aim of finding steroid esters which show distinctly higher helical twisting power (HTP) than cholesteryl 3,4-di-(2-acryloyloxyethoxy)benzoate. Isothermal photopolymerization led to crosslinked networks. The HTPs of the networks were determined by measuring the reflection wavelengths and their dependence on the molar fraction of the chiral compound. The relationship between the HTP of the cholesteric polymeric networks and the molecular structure of the chiral steroid ester is discussed. A high HTP can be attributed to the definite alignment imposed by the large substituents on the long axis of the steroid nucleus.