Molecular-engineered hybrid carbon nanofillers for thermoplastic polyurethane nanocomposites with high mechanical strength and toughness

Abstract The development of strong-yet-ductile polymer nanocomposites is critical, but still faces a great challenge. Herein, a hybrid carbon nanofiller consisting of one-dimensional carbon nanotube (CNT) and two-dimensional graphene (G) was molecularly engineered, and the as-prepared G-CNT hybrid nanofiller was then solution-casted with thermoplastic polyurethane (TPU) for the fabrication of TPU nanocomposite films. Due to the formation of unique network structure with multiple interactions of G-CNT hybrid within TPU matrices, the as-fabricated TPU nanocomposites showed simultaneously improved mechanical strength and toughness. With addition of only 1 wt% G-CNT hybrid, the tensile strength and toughness of TPU/(G-CNT) nanocomposite reached 69.5 MPa and 246.2 MJ m−3, 1.9 and 2.9 times over that of neat TPU, respectively. The significant and simultaneous enhancement in mechanical strength and toughness of TPU nanocomposites is attributed to homogeneously distributed G-CNT hybrid and its unique energy dissipations due to factures at different deformation stages upon tensile deformation. The work therefore provides a simple and efficient strategy for fabricating mechanically strong and ductile polymer nanocomposites with molecular-engineered hybrid carbon nanofillers.