Self-assembled poly(4-vinylpyridine) - Surfactant systems using alkyl and alkoxy phenylazophenols

Para-substituted alkyl and alkoxy phenylazophenols (PAP's) have been synthesized and used as hydrogen-bonded side chains for poly(4-vinylpyridine)-based comb-shaped supramolecules akin to the well-studied poly (4-vinylpyridine)/pentadecyl phenol systems. In this paper we report the self-assembly of these new materials as investigated by DSC and simultaneous SAXS/WAXS. The systems exhibit smectic ordering with a periodicity in the range of 3.0-4.2 nm. The periodicity length scale, the order-disorder transition temperature (T-ODT), and the glass transition temperature T-g of the self-assembled systems all increase with increasing alkyl chain length. The correlation between T-ODT and T-g observed is argued to be the consequence of the increasing segregation in the self-assembled systems with increasing alkyl tail length of the amphiphiles.