Supramolecular assembly between polystyrene-block-poly(4-vinylpyridine) and 4-dodecylbenzenesulfonic acid

In this study, the desired polymer was prepared by complexing the surf molecule, i.e., 4-dodecylbenzenesulfonic acid (DBSA), with polystyrene-block-poly(4-vinylpyridine) (PS-P4VP) and a comb-coil A-block-(B-graft-C) type of copolymer can be generated through a supramolecular assembly route. On the block copolymer scale, the PS blocks are phase-separated from the P4VP(DBSA)(x) block (x denotes the molar ratio between DBSA and pyridine groups) according to the relatively constant low-temperature glass transition (T-g) corresponding to the PS phase. In contrast, the high-temperature T-g increased with the DBSA content; a fact associated with the chain packing situation in the P4VP(DBSA)(x) block. Both low and high T-g's became more visible if samples were subjected to a two-stage annealing process. Corresponding X-ray diffraction study also indicates that annealing enhanced the layered structure in the P4VP(DBSA)(x) phase. The corresponding one-dimension correlation function suggests that both polymer and surfactant layers increased with the increasing DBSA content. In addition, amounts of the associated DBSA related to the formation of macroscopic anisotropic domains, that is, birefrigency can only be detected for copolymers of high P4VP(DBSA)(x) content (> 70 wt%).