Tuning Nanostructure and Mechanical Properties in Polymer Materials via Reaction-Induced Phase Transitions

Material structure is the intersection between chemistry and property. An exciting way to control polymer material nanostructure is to drive macromolecular transformations via reaction-induced phase transitions. Recently, our group has shown how in situ polymer grafting strategies transform linear diblock copolymers into multi-graft copolymers, inducing order-order and disorder-order structural transitions. In the reported approach, a poly(styrene)-block-poly(butadiene) (PS-PBD) diblock copolymer swollen with styrene monomer will undergo lamellar-to-hexagonally-packed cylinder or a disordered-to-hexagonally-packed cylinder transition during the polymerization of styrene, which is a result of PS grafting from the PBD block. Here, the presentation will demonstrate how the in situ polymer grafting process previously used for diblock copolymers is easily applied to PS-PBD-PS triblock copolymers and hybrid polymer/inorganic nanoparticle systems, resulting in materials with enhanced mechanical properties or controlled nanoparticle dispersions, respectively. The work presented here emphasizes how in situ grafting strategies drive macromolecular transformations, leading to materials with controllable nanoscale morphologies and physical properties.