Nanoscale control of structure in polymer nanocomposites is critical for their performance but has been difficult to investigate systematically due to the lack of a suitable experimental model. In this work, we investigated the role of nanoparticle layer separation in the finite deformation response of layered polyurethane(PU-) montmorillonite (MTM) nanocomposites. A series of multilayered nano...

Metallic glasses, like many other glasses and ceramics, generally have zero tensile ductility. Distinct from common wisdom which seeks to toughen brittle with ductile phases, we show that composites made two can be ductile, strong even harden under tension as a result of microstructure stiffness contrast. Using molecular dynamics simulations, designed tested consisting alternating wavy nanofila...

While the low thermal conductivities of silica aerogels have made them of interest to the aerospace community as lightweight thermal insulation, the application of conformal polymer coatings to these gels increases their strength significantly, making them potentially useful as structural materials as well. In this work we perform multiscale computer simulations to investigate the tensile and c...

The effect of static and cyclic loading conditions on the stress corrosion cracking of unidirectional glass reinforced polymer (GRP) rods used in composite high voltage insulator has been investigated. A series of stress corrosion experiments have been performed on unidirectional E-glass/modified polyester composite rods. The rods have been subjected to mechanical tensile static and cyclic stre...

Multiple healing cycles of a single crack in a brittle polymer coating are achieved by microvascular delivery of a two-part, epoxy-based self-healing chemistry. Epoxy resin and amine-based curing agents are transported to the crack plane through two sets of independent vascular networks embedded within a ductile polymer substrate beneath the coating. The two reactive components remain isolated ...

Understanding the mechanism of fracture is essential for material and process design. While the initiation of fracture in brittle solids is generally associated with the preexistence of material imperfections, the mechanism for initiation of fracture in viscoelastic fluids, e.g., polymer melts and solutions, remains an open question. We use high speed imaging to visualize crack propagation in e...

The micromechanical deformation mechanisms of a polylactic acid (PLA)/natural rubber (NR) blend (PLA/NR 90/10 wt%) and its organoclay filled bionanocomposites have been investigated by small and wide angle X-ray scattering (SAXS–WAXS) under tensile conditions. The addition of NR to a PLA matrix changed the brittle fracture of PLA to a ductile deformation through the debonding of the rubber drop...