PREPARATION OF ORDERED AND CROSS-LINKED FILMS FROM LIQUID-CRYSTALLINEP-VINYLPHENOXY-BASED MONOMERS

The synthesis of the following monofunctional and bifunctional liquid crystalline p-vinylphenoxy-based monomers is described: 4-methoxypheny l 4-[11-(4-vinylphenoxy)undecyloxy)]benzoate (1), 4-cyanophenyl 4-[11- (4-vinylphenoxy)undecyloxy]benzoat (2) and 3-(4-vinylphenoxy)propyl [1 1-(4-vinylphenoxy)undecyloxy]benzoyloxy]benzoate (3). Both free radica l and cationic polymerization of the monofunctional monomers 1 and 2 y ielded side-chain liquid crystalline polymers exhibiting smectic A mes omorphism. The polymers exhibited high molar masses ((M) over bar(n) = 40000 - 100000 g/mol) and relatively narrow molar mass distributions ((M) over bar(w)/(M) over bar(n) between 1.5 and 3). Ordered thin film s were prepared by in-situ photopolymerization of monomers 1, 2 and 3 oriented in their nematic mesophases. Thin films of a thermally stabil ized ordered side-chain liquid crystalline polymer were prepared by co polymerization of the monofunctional monomer 1 and the bifunctional mo nomer 3, the latter present in low concentration. The films regained o rientation when cooled down from temperatures above the isotropization point (137 degrees C) as evidenced by polarized FT-Raman measurements .