Studies on Liquid Crystalline-Cum-Photocrosslinkable Polymers

This book sketches the studies of two series of liquid crystalline-cum-photocrosslinkable polymers were synthesized from two different monomers, one monomer containing chalcone unit and the other monomer containing organophosphorus unit. The chalcone unit was used as a photosensitive-cum-mesogenic segment and was prepared by the reaction of cycloalkanones (cyclopentanone, cyclohexanone) with vanillin in absolute ethanol using an acid catalyst. The methylene chain extended chalcone derivatives were prepared by the nucleophilic displacement of the potassium salt of bisvanillylidene with n-bromo-1-alkanols (n=6,8,10) in DMF. Various arylphosphorodichloridates prepared by reacting the corresponding phenols viz.,phenol, 1-naphthol and 4-phenylphenol,with excess of phosphorus oxychloride.The pure dichloridates were obtained by vacuum distillation. The liquid crystalline properties of the polymers were examined by hot stage optical polarizing microscopy. All the polymers exhibited liquid crystalline behavior. The hexamethylene spacer containing polymers exhibited grainy textures and other polymers such as octamethylene and decamethylene spacer containing polymers showed nematic textures.