Molecular engineering of liquid crystal polymers by living polymerization. II. Living cationic polymerization of 11‐[(4‐cyano‐4′‐biphenyl) oxy] undecanyl vinyl ether and the mesomorphic behavior of the resulting polymers

Abstract

The synthesis and living cationic polymerization of 11‐[(4‐cyano‐4′‐biphenyl)oxy]‐undecanyl vinyl ether (6–11) are described. The mesomorphic phase behavior of poly(6–11) with different degrees of polymerization was compared to that of 6–11 and of 11‐[(4‐cyano‐4′‐biphenyl) oxy] undecanyl ethyl ether (8–11) which is the model compound of the monomeric structural unit of poly(6–11). 6–11 displays a monotropic SA and a monotropic nematic mesophase while 8–11 an enantiotropic SA mesophase. Poly(6–11) with low degrees of polymerization exhibits an enantiotropic SA mesophase. Poly(6–8) with high degrees of polymerization displays an enantiotropic SX (i. e., an unidentified smectic phase) and an enantiotropic SC mesophase. These results demonstrate that the transformation of the nematic mesophase of the monomer into a smectic mesophase after polymerization, occurs at the level of monomeric structural unit.

Soluble rigid-flexible polyethers containing bis(biphenyl)anthracene or bis(styryl)anthracene units in the main chain for light-emitting applications

“…9,10-Dibromo-anthracene 42 and 4-acetoxy-4Ј-bromo-biphenyl 43 were synthesized according to known procedures. 9,10-Anthracene bisboronic acid was synthesized according to a procedure reported for phenylene derivatives.…”

Synthesis and properties of amorphous blue‐light‐emitting polymers with high glass‐transition temperatures

“…Chemicals were purchased from Aldrich and used as received unless otherwise specified. 2,5‐Dialkoxy‐1,4‐phenyldiboronic acids,29 2,5‐dialkyl‐1,4‐phenyldiboronic acid,30 2′,3′,5′‐triphenyl‐ p ‐terphenyl‐4‐4″‐diol,31 2″,3″,5″‐triphenyl‐ p ‐quinquephenyl‐4‐4″″‐diol,31 2′,5′‐dihexyloxy‐ p ‐terphenyl‐4‐4″‐diol,32 2″,5″‐dihexyloxy‐ p ‐quinquephenyl‐4‐4″″‐diol,18 4‐acetoxybromobenzene, 4‐acetoxy‐4′‐bromobiphenyl,33 and bis(fluorophenyl)phenylphosphine oxide34 were synthesized according to reported procedures. Dimethylformamide (DMF) was distilled and kept under molecular sieves.…”

Design and Synthesis of Side‐Chain Liquid Crystal Polymers

“…For sufficient mobility of the mesogenic side groups, a spacer length of at least 11 is desirable. The influence of the spacer was examined for polyvinylethers [24,[50][51][52][53][54]. Figure 11.15 shows the phase transitions of liquid-crystalline-branched polyethyleneimines (P11) (M n : ∼ 10 000) with mesogenic side groups [55].…”