Manipulation of Fracture Behavior of Polymethylmethacrylate Nanocomposites by Interfacial Design of Metal-Organic-Framework Nanoparticle Toughener.

The interfacial region between nanoparticles and polymer matrix plays a critical role in influencing the mechanical behavior of polymer nanocomposites. In this work, a set of model systems based on polymethylmethacrylate (PMMA) matrix containing polyalkylglycidylether brushes grafted on 50 nm metal-organic-framework (MOF) nanoparticles were synthesized and investigated. By systematically increasing the polymer brush length and graft density on the MOF nanoparticles, the fracture behavior of PMMA/MOF nanocomposite changes from forming only a few large crazes to generating massive crazing, and to undergoing shear banding, which results in significant improvement in fracture toughness. The implication of the present finding for the interfacial design of nanoparticles for the development of high performance, multi-functional polymer nanocomposites is discussed.