The Experts below are selected from a list of 105 Experts worldwide ranked by ideXlab platform

M Ramji - One of the best experts on this subject based on the ideXlab platform.

Scott R. White - One of the best experts on this subject based on the ideXlab platform.

  • Life extension of self-healing Polymers with rapidly growing fatigue cracks
    Journal of the Royal Society Interface, 2007
    Co-Authors: A. S. Jones, Joseph D. Rule, Nancy R Sottos, Jeffrey S. Moore, Scott R. White
    Abstract:

    Self-healing Polymers, based on microencapsulated dicyclopentadiene and Grubbs' catalyst embedded in the Polymer matrix, are capable of responding to propagating fatigue cracks by autonomic processes that lead to higher endurance limits and life extension, or even the complete arrest of the crack growth. The amount of fatigue-life extension depends on the relative magnitude of the mechanical kinetics of crack propagation and the chemical kinetics of healing. As the healing kinetics are accelerated, greater fatigue life extension is achieved. The use of wax-protected, recrystallized Grubbs' catalyst leads to a fourfold increase in the rate of Polymerization of bulk dicyclopentadiene and extends the fatigue life of a Polymer Specimen over 30 times longer than a comparable non-healing Specimen. The fatigue life of Polymers under extremely fast fatigue crack growth can be extended through the incorporation of periodic rest periods, effectively training the self-healing Polymeric material to achieve higher endurance limits.

A. S. Jones - One of the best experts on this subject based on the ideXlab platform.

  • Life extension of self-healing Polymers with rapidly growing fatigue cracks
    Journal of the Royal Society Interface, 2007
    Co-Authors: A. S. Jones, Joseph D. Rule, Nancy R Sottos, Jeffrey S. Moore, Scott R. White
    Abstract:

    Self-healing Polymers, based on microencapsulated dicyclopentadiene and Grubbs' catalyst embedded in the Polymer matrix, are capable of responding to propagating fatigue cracks by autonomic processes that lead to higher endurance limits and life extension, or even the complete arrest of the crack growth. The amount of fatigue-life extension depends on the relative magnitude of the mechanical kinetics of crack propagation and the chemical kinetics of healing. As the healing kinetics are accelerated, greater fatigue life extension is achieved. The use of wax-protected, recrystallized Grubbs' catalyst leads to a fourfold increase in the rate of Polymerization of bulk dicyclopentadiene and extends the fatigue life of a Polymer Specimen over 30 times longer than a comparable non-healing Specimen. The fatigue life of Polymers under extremely fast fatigue crack growth can be extended through the incorporation of periodic rest periods, effectively training the self-healing Polymeric material to achieve higher endurance limits.

J. C. Seferis - One of the best experts on this subject based on the ideXlab platform.

  • Influence of Polymer Specimen Structure on The Reproducibility of Micro-thermomechanical Transitions
    Journal of Thermal Analysis and Calorimetry, 2000
    Co-Authors: M. S. Tillman, T. Takatoya, B. S. Hayes, J. C. Seferis
    Abstract:

    Glass transitions of amorphous polystyrenes with low polydispersity were evaluated using the modulated Local Thermal Analysis mode of the TA Instruments 2990 µ TA and evaluating the thermomechanical signal. Transition temperature variance and fraction of transitions measured were compared for high molecular mass thermosetting materials and the melt of Nylon 6.6. The transition reproducibility was found to decrease as the molecular size of the Polymer samples increased. Reproducibility also decreased for thermosetting materials when the experimental ramp rate was decreased. Heat transfer within the Specimen was evaluated using finite element analysis, allowing scaling of microscale experimental results for comparison to bulk transitions.

H. Daniel Wagner - One of the best experts on this subject based on the ideXlab platform.

  • Measurement of carbon nanotube-Polymer interfacial strength
    Applied Physics Letters, 2003
    Co-Authors: Asa H. Barber, Sidney R. Cohen, H. Daniel Wagner
    Abstract:

    The force required to separate a carbon nanotube from a solid Polymer matrix has been measured by performing reproducible nanopullout experiments using atomic force microscopy. The separation stress is found to be remarkably high, indicating that carbon nanotubes are effective at reinforcing a Polymer. These results imply that the Polymer matrix in close vicinity of the carbon nanotube is able to withstand stresses that would otherwise cause considerable yield in a bulk Polymer Specimen.