SYNTHESIS AND LIQUID CRYSTALLINITY OF STEREOREGULAR POLYMETHACRYLATES WITH MESOGENIC ESTER GROUPS

2-[4-(4'-Methoxyphenyl)phenoxy]ethyl, 3-[4-(4'-methoxyphenyl)phenoxy]propyl, 4-[4-(4'-methoxyphenyl)phenoxy]butyl, 5-[4-(4'-methoxyphenyl)phenoxy]pentyl, and 6-[4-(4'-methoxyphenyl)-phenoxy]hexyl methacrylates were synthesized and polymerized. Anionic polymerization of these monomers was carried out with tert-butylmagnesium bromide in toluene, chloroform, and tetrahydrofuran at low temperature, and radical polymerization was conducted with alpha,alpha'-azobis(isobutyronitrile) in toluene at 60-degrees-C. Highly isotactic (mm 90-97%) and syndiotactic (rr 79-86%) polymers were obtained by anionic polymerization in chloroform and tetrahydrofuran, respectively, and polymers rich in syndiotacticity (rr 56-66%) were obtained by radical polymerization. Thermal properties and liquid crystallinities of the polymers depended greatly on both the tacticity of the main chain and the length of the methylene chain (spacer) in the side group. These observations were interpreted in terms of zigzag (alt-trans) and helical conformations of the main chain of syndio- and isotactic polymers, respectively, and the all-trans conformation of the spacer chain.