Molecular engineering of liquid-crystalline polymers by ‘living’ polymerization. Part 30.—Synthesis and ‘living’ cationic polymerization of (2R, 3S)-2-fluoro-3-methylpentyl 4′-(8-vinyloxyoctyloxy)biphenyl-4-carboxylate and its copolymerization with (2R, 3S)-2-fluoro-3-methylpentyl 4′-(11-vinyloxyundecanyloxy)biphenyl-4-carboxylate

Abstract

The synthesis and living cationic polymerization of (2R, 3S)-2-fluoro-3-methylpentyl 4′-(8-vinyloxyoctyloxy)biphenyl-4-carboxylate (11–8) are described. Poly(11–8)s with degrees of polymerization (DP) from 4.3 to 15.7 and polydispersities ⩽ 1.19 were synthesized and characterized by differential scanning calorimetry (DSC) and thermal optical polarized microscopy. All poly(11–8)s exhibit an enantiotropic S_c* and an unidentified smectic (S₁) phase. Poly(11–8)s with DP 11.5 exhibit an additional enantiotropic unidentified smectic (S₂) phase. No S_A phase could be detected in any of the poly(11–8)s. The nature of the mesophases exhibited by poly(11–8) was confirmed by the investigation of the phase diagram of the copolymers prepared from 11–8 and (2R, 3S)-2-fluoro-3-methylpentyl 4′-(11-vinyloxyundecanyloxy)biphenyl-4-carboxylate (11–11). The S_c* phase of these copolymers displays a continuous dependence of copolymer composition.