Synthesis of novel sulfonyl‐containing liquid‐crystalline side‐chain poly(vinyl ethers)

The synthesis of some new liquid‐crystalline polymers with sulfonyl‐containing mesogenic groups is described. 4‐[(S)‐(‐)‐2‐MethylbutyIsulfonyl]‐4′‐[(11‐vinyloxy)undecyloxy]biphenyl (10‐11), 4‐[(S)‐(‐)‐2‐methylbutylsulfonyl]‐4′‐[8‐(vinyloxy)octyloxy]biphenyl (10‐8), 4‐[(S)‐(‐)‐2‐ methylbutylsulfonyl]biphenyl 4‐[11‐(vinyloxy)undecyloxy]benzoate (12‐11), 4‐[(S)‐(‐)‐2‐methylbutylsulfonyl]biphenyl 4‐[8‐(vinyloxy)octyloxy]benzoate (12‐8), 4‐[(S)‐(‐)‐2‐methylbutyloxy]‐4′‐ [11‐(vinyloxy)undecylsulfonyl]biphenyl (18‐11) and 2‐[11‐(vinyloxy)undecyloxy]‐6‐{4‐[(S)‐(‐)‐2‐ methylbutylsulfonyl]phenyl}naphthalene (23‐11) were all synthesized, and polymerized with the initiating system CF3SO3H/S(CH3)2 in CH3Cl3 at 0°C. Monomers 10‐11, 10‐8, 18‐11 and 23‐11 are crystalline, while both 12‐11 and 12‐8 show an enantiotropic smectic A phase. All polymers exhibit the same thermotropic behaviour as their corresponding monomers, except poly(23‐11) which exhibits an enantiotropic smectic A (sA) and a monotropic chiral smectic C phase (S*C).