MOLECULAR ENGINEERING OF LIQUID-CRYSTAL POLYMERS BY LIVING POLYMERIZATION .23. SYNTHESIS AND CHARACTERIZATION OF AB BLOCK COPOLYMERS BASED ON OMEGA-[(4-CYANO-4'-BIPHENYL)-OXY]ALKYL VINYL ETHER, 1H,1H,2H,2H-PERFLUORODECYL VINYL ETHER, AND 2-(4-BIPHENYLOXY)ETHYL VINYL ETHER WITH 1H,1H,2H,2H-PERFLUORODECYL VINYL ETHER

This paper describes the synthesis and characterization of AB block copolymers based on omega-[(4-cyano-4'-biphenyl)oxy]alkyl vinyl ether (6-n), with alkyl being ethyl (6-2), propyl (6-3), nonyl (6-9), and undecanyl (6-11), with 1H,1H,2H,2H-perfluorodecyl vinyl ether (CF8), poly[(6-n)-b-CF8]X/Y (where X/Y refers to the weight ratio of the two segments), and of 2-(4-biphenyloxy)ethyl vinyl ether (BEVE) with 1H,1H,2H,2H-perfluorodecyl vinyl ether, poly[BEVE-b-CF8]X/Y. They were prepared by living cationic polymerization and exhibit a narrow molecular weight distribution. All block copolymers display a microphase-separated morphology when the A segment is in the liquid crystalline phase. Block copolymers based on 6-2, 6-3, and BEVE with CF8 also exhibit a microphase-separated morphology in the melt phase of A and B blocks.