Segmented liquid crystalline polyesters with allyl group as lateral substituent

The synthesis and a partial characterization of segmented liquid crystalline polymers with 3,3′-diallyl-4,4′-dihydroxybiphenyl unit in the rigid moiety is reported. The general formula of polymers is -p-C₆H₄-COO-p-C₆H₃(R)-p-C₆H₃(R)-OOC-p-C₆H₄-O-(CH₂)_nO-]_x, with n = 6, 8, 10, 12, and R =  CH₂ CHCH₂. All polymers have nematic liquid-crystalline behavior. At room temperature, annealed fiber samples of polymers show a complex polymorphism. Three phases have been isolated with very large unit cells accommodating 6 or 12 chains. The projection of the molecular packing in a plane perpendicular to the c axis is characterized by the organization of chains in a two-dimensional hexagonal or quasi-hexagonal array. © 1998 John Wiley & Sons, Inc. J. Polym. Sci. B Polym. Phys. 36: 2371–2378, 1998