The Experts below are selected from a list of 1755 Experts worldwide ranked by ideXlab platform

Shinyoung Kaang - One of the best experts on this subject based on the ideXlab platform.

  • Effects of particle size and structure of carbon blacks on the abrasion of Filled Elastomer compounds
    Journal of Materials Science, 2007
    Co-Authors: Chang Kook Hong, Shinyoung Kaang
    Abstract:

    The effects of the particle size and structure of various carbon blacks on friction and abrasion behavior of Filled natural rubber (NR), styrene–butadiene rubber (SBR) and polybutadiene (BR) compounds were investigated using a modified blade abrader. The effect of particle size and structure on abrasion resistance should be considered for the optimum design of desired wear properties. Characteristic parameters were introduced from the particle size and the structure of carbon blacks, with a linear relationship between the Young’s modulus and these characteristic parameters. The frictional coefficient depended not only on the particle size, but also on the structure of carbon black. The rates of abrasion were decreased with increasing surface area and developing structure of carbon blacks. Abrasion rates of the compounds were found to be proportional to a power n of the applied frictional work input. It was also observed that BR compounds caused much slower wear than NR and SBR compounds. The worn surfaces of the rubber compounds Filled with carbon black having smaller particle size and a more developed structure showed narrower spaced ridges and better abrasion resistance. It means that smaller particle size and better structure development of carbon black resulted in improved abrasion resistance.

Costantino Creton - One of the best experts on this subject based on the ideXlab platform.

  • Covalent Bond Scission in the Mullins Effect of a Filled Elastomer: Real-Time Visualization with Mechanoluminescence
    Advanced Functional Materials, 2016
    Co-Authors: Jess M. Clough, Costantino Creton, Stephen L. Craig, Rint P. Sijbesma
    Abstract:

    Strain-induced light emission from mechanoluminescent cross-linkers in silica-Filled poly(dimethylsiloxane) demonstrates that covalent bond scission contributes significantly to irreversible stress-softening upon the initial extension, known as the Mullins effect. The cross-linkers contain dioxetanes that emit light upon force-induced bond scission. The Filled Elastomer emits light in cyclic uniaxial tension, but only on exceeding the previous maximum strain. The amount of light increases with hysteresis energy in a power law of exponent 2.0, demonstrating that covalent bond scission becomes increasingly important in the strain regime studied. Below 100%–120% strain, corresponding to energy absorption of (0.082 ± 0.012) J cm−3, mechanoluminescence is not detectable. Calibration of the light intensity indicates that by 190% strain, less than 0.1% of the dioxetane moieties break. Small but significant amounts of light are emitted upon unloading, suggesting a complex stress transfer to the dioxetanes mediated by the fillers. Pre-strained material emits light on straining perpendicularly, but not parallel to the original tensile direction, demonstrating that covalent bond scission is highly anisotropic. These findings show that the scission of even a small number of covalent bonds plays a discernible role in the Mullins effect in Filled silicone Elastomers. Such mechanisms may be active in other types of Filled Elastomers.

  • Nanocavitation around a crack tip in a soft nanocomposite: A scanning microbeam small angle X-ray scattering study
    Journal of Polymer Science Part B: Polymer Physics, 2015
    Co-Authors: Huan Zhang, Jordan De Crevoisier, Daniel Berghezan, Arthur K. Scholz, Theyencheri Narayanan, Edward J. Kramer, Costantino Creton
    Abstract:

    We explore nanocavitation around the crack tip region in a styrene-butadiene random copolymer Filled with typical carbon black (CB) particles used in the rubber industry for toughening the rubber. Using quasistatic loading conditions and a highly collimated X-ray microbeam scanned around the crack tip, we demonstrate the existence of a damage zone consisting of nanovoids in a Filled Elastomer matrix. The existence of voids near the crack tip is demonstrated by a significant increase of the scattering invariant Q/Q0 in front of both fatigued and fresh cracks. The size of the zone where cavities are present critically depends on the macroscopic strain εm, the loading history, and the maximum energy release rate G applied to accommodate the crack. Our findings show that nanovoiding occurs before fracture in typical CB-Filled Elastomers and that realistic crack propagation models for such Elastomers should take into account a certain level of compressibility near the crack tip

  • Volume changes in a Filled Elastomer studied via digital image correlation
    Polymer Testing, 2012
    Co-Authors: Jordan De Crevoisier, Costantino Creton, Gilles Besnard, Yannick Merckel, Huan Zhang, Julien Caillard, Fabien Vion-loisel, Daniel Berghezan, Julie Diani, Mathias Brieu
    Abstract:

    Volumetric strains in a Filled SBR specimen subjected to cyclic uniaxial tension with increasing extensions are studied. Digital image correlation is used to follow the kinematics of two orthogonal free faces. A volume expansion is observed past a critical elongation, which can be interpreted as the onset of cavitation. Under unloading, the volume returns to its original value and remains constant upon reloading. Increasing the elongation to higher values than the previous cycle leads again to a volumetric expansion.

X. Wang - One of the best experts on this subject based on the ideXlab platform.

  • Spectral hole burning to probe the nature of unjamming (Payne effect) in particle-Filled Elastomers
    Europhysics Letters (EPL), 2006
    Co-Authors: Christopher G. Robertson, X. Wang
    Abstract:

    The Payne effect is a low-strain hysteretic softening in particle-Filled Elastomers which we recognize as part of jamming physics. We find that aging at a fixed oscillatory strain produces a hole in the unjamming loss modulus spectrum which is localized near the aging strain for a silica-Filled Elastomer. This cannot be predicted by any existing Payne effect model. By applying the Einstein fluctuation-dissipation relation and comparing our findings to nonequilibrium glassy behavior, we show that oscillatory strain amplitude in particle-Filled Elastomers can be interpreted as an effective temperature.

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

  • Reinforcement of model Filled Elastomers: experimental and theoretical approach of swelling properties
    Polymer, 2002
    Co-Authors: J Berriot, F Lequeux, H Montes, H Pernot
    Abstract:

    The swelling properties of model Filled Elastomers consisting of crosslinked polyethylacrylate chains mixed with grafted silica nanoparticles are analysed using a continuous media mechanics approach. We show that the swelling restriction observed in these Filled Elastomers cannot be simply explained through the increase of the topological constraints density resulting from the interactions at the interface between the particles and the polymer chains. Strong interactions at the particle/matrix interface lead to geometrical constraints which control and restrict the swelling of the polymer network. We propose a model giving an analytical relation between the swelling properties of the Filled Elastomer, one of the Elastomer without particles, and the volume fraction of solid particles. This model describes relatively well the experimental data obtained for varying topological constraint density at the particle surface.

A. V. Chapman - One of the best experts on this subject based on the ideXlab platform.

  • TEM observation of silane coupling agent in silica-Filled rubber tyre compound
    Journal of Rubber Research, 2019
    Co-Authors: Y. W. Ngeow, J. Y. Y. Heng, D. R. Williams, R. T. Davies, K. M. E. Lawrence, A. V. Chapman
    Abstract:

    The microdispersion of silica in Filled Elastomer vulcanisates was evaluated by transmission electron microscopy (TEM)—network visualisation analysis. In this study, the silica is modified with a wide range of coupling and non-coupling silanes. The silica-Filled Elastomer samples were microtomed using a glass knife. The resulting TEM micrographs were interpreted and characterised based on aggregates with a cross-sectional area larger than 100 nm^2. The study showed that silica surface modification has reduced the silica aggregate size by approximately 30–40% compared to an untreated silica-Filled Elastomer vulcanisate. The TEM micrographs showed evidence of coupling between silica and the Elastomer phase and demonstrated a good estimation of silica microdispersion in the Elastomer phase. This study has shown that the presence of different surface functionalities has an effect on the silica microdispersion.

  • TEM observation of silane coupling agent in silica-Filled rubber tyre compound
    Journal of Rubber Research, 2019
    Co-Authors: Y. W. Ngeow, J. Y. Y. Heng, D. R. Williams, R. T. Davies, K. M. E. Lawrence, A. V. Chapman
    Abstract:

    The microdispersion of silica in Filled Elastomer vulcanisates was evaluated by transmission electron microscopy (TEM)—network visualisation analysis. In this study, the silica is modified with a wide range of coupling and non-coupling silanes. The silica-Filled Elastomer samples were microtomed using a glass knife. The resulting TEM micrographs were interpreted and characterised based on aggregates with a cross-sectional area larger than 100 nm^2. The study showed that silica surface modification has reduced the silica aggregate size by approximately 30–40% compared to an untreated silica-Filled Elastomer vulcanisate. The TEM micrographs showed evidence of coupling between silica and the Elastomer phase and demonstrated a good estimation of silica microdispersion in the Elastomer phase. This study has shown that the presence of different surface functionalities has an effect on the silica microdispersion.