Hydrogen bonding mediated microphase-separated structures in sbm triblock copolymer blends

The self-assembly of ABC triblock copolymer/homopolymer blends where the homopolymer is miscible with one of the blocks (C) and immiscible with the other two blocks (A and B) of the block copolymer were investigated. The well-known proton donating polymers, namely, phenoxy and poly (4-vinyl phenol) (PVPh) were used to prepare the self-assembled SBM triblock copolymer blends. In these blends, microphase separation takes place due to the disparity in intermolecular interactions; specifically, the homopolymer interacts with PMMA blocks through hydrogen bonding interactions. In both PVPh/SBM and phenoxy/SBM blends, order to disorder morphology transitions were observed with increase in homopolymer content. The TEM and SAXS results of phenoxy/SBM show lamellar, bicontinuous and other disordered nanostructures; whereas in PVPh/SBM, lamellae, hexagonal close packed cylinders, and other complex disordered nanostructures were observed. Here we examined how intermolecular hydrogen bonding interaction between the homopolymer and block copolymer can alter the morphologies of the blends