Liquid-crystalline copolymers of cholesteric type

Abstract

Results are presented of investigations into the structure and liquid-crystalline properties of copolymers of cholesteric ester of 15-methacryloyloxypentadecanoic acid with p-methoxyphenyl ester of p′-(2-methacryloyloxyethoxy)benzoic acid (copolymer I) and p-methoxydiphenyl ester of p′-(2-methacryloyloxyethoxy)benzoic acid (copolymer II). All copolymers above T g change into the liquid-crystalline state, which is characterized by spontaneous anisotropy, that may be “frozen” in a glassy matrix below T g. With a content of cholesterol-containing component of 12–24 mole% copolymer II forms a liquid-crystalline phase of cholesteric type recorded by the existence of selective light reflection. The wave length of maximum selective light reflection which is in the IR range, λ max remains constant below T g and on increasing temperature, is displaced in the long-wave range.