Self-assembly of a triblock terpolymer mediated by hydrogen-bonded complexes

A poly(methyl methacrylate)-block-poly(4-vinylpyridine)-block-polystyrene (PMMA-b-P4VP-b-PS) triblock terpolymer is synthesized by ATRP to study its self-assembly with PAA in organic solvents. The self-assembly behavior of this system is compared with the one of a mixture of two diblocks, namely polystyrene-block-poly(4-vinylpyridine) (PS-b-P4VP) and poly(methyl methacrylate)-block-poly(methacrylic acid) (PMMA-b-PMAA). For both systems, formation of hydrogen-bonded complexes between the P4VP and PMAA or PAA blocks occurs. These complexes become insoluble in the solvent used and micelles with a P4VP/P(M)AA complexes core surrounded by PS and PMMA coronal chains are obtained in both cases. These micelles are analyzed by DLS and TEM. Spherical micelles are formed for both systems but the hydrodynamic radii obtained for the two types of micelles are different. Indeed, the micelles formed by the PMMA-b-P4VP-b-PS + PAA system are smaller than those observed for the PS-b-P4VP + PMMA-b-PMAA system. Finally, the effect of the molar ratio of the P4VP/PMAA complexing blocks is investigated.