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Dielectric constant and morphology of BaTiO3-polymer composite films were studied as a function of the filler concentration. The morphology of the films was examined using laser scanning confocal microscopy, which is capable to measure small particle
Joy P. Dunkers, Joseph~undefined~undefined~undefined~undefined~undefined Lenhart, S R. Kueh, J H. VanZanten, S G. Advani, Richard~undefined~undefined~undefined~undefined~undefined Parnas
The Polymer Composites group at the National Institute of Standards and Technology has efforts in both on-line flow and cure sensing for liquid composite molding. For our flow program, a novel fiber optic real time sensor system has been developed that can
The broadband dielectric relaxation of a BaTiO3-polymer composite film was studied. The complex dielectric constant data from 10 -4 Hz to 10 10 Hz reveals the existence of a relaxation process at a frequency of 10 MHz in the polymer composite. On the basis
The dielectric properties of acrylic resin composites filled with BaTiO 3 have been evaluated in the broad frequency range. These materials were used as models to study the dielectric response in polymer composite films for de-coupling capacitance
Joy Dunkers, Frederick R. Phelan Jr., D P. Sanders, M J. Everett, William H. Green, Donald L. Hunston, Richard~undefined~undefined~undefined~undefined~undefined Parnas
The Composites Group at the National Institute of Standards and Technology has found optical coherence tomography (OCT) to be a powerful tool for non-destructive characterization of polymer matrix composites. Composites often exhibit superior properties to
hesion at the fiber matrix interface of composite specimens is often ascribed to the following factors (Sharpe and Drzal): (1) mechanical interlocking, (2) physicochemical interactions, (3) chemical bonding, and (4) mechanical deformation of the fiber
Joseph M. Antonucci, Drago Skrtic, A W. Hailer, E D. Eanes
Amorphous calcium phosphate (ACP), an important precursor in the biological formation of hydroxyapatite (HAP), has recently been utilized as a bioactive filler in resin-based dental materials. It was found that, if ACP was stabilized against premature
Fiber-matrix interface strength is known to be a critical factor in controlling the long-term performance of structural composites. This parameter is often obtained by using the average fragment length data generated from the single-fiber fragmentation
Gale A. Holmes, Walter G. McDonough, R C. Peterson, Donald L. Hunston
In this paper the nonlinear viscoelastic response of the diglycidyl ether of bisphenol-A (DGEBA)/meta-phenylenediamine (m-PDA) matrix was correlated with changes in the final fragment distribution. The changes in the final fragment distribution were
Gale A. Holmes, Donald L. Hunston, Walter G. McDonough, R C. Peterson
Two of the critical factors controlling the long-term performance and durability of composites in structural applications is the fiber-matrix interfacial shear strength (IFSS) and the durability of the fiber-matrix interface. The single fiber fragmentation
Joy Dunkers, M J. Everett, D P. Sanders, Donald L. Hunston
The Composites Group at the National Institute of Standards and Technology has found optical coherence tomography (OCT) to be a powerful tool for non-destructive characterization of polymer matrix composites. Composites can be made more cost competitive by
Joy Dunkers, D P. Sanders, Donald L. Hunston, M J. Everett
Resistance to impact damage is extremely important for most composites. Such damage can initiate delamination, one of the most common failure modes in composites.. Because this is such an important failure mode, many studies have tried to develop matrix
Walter G. McDonough, Joseph M. Antonucci, Gary E. Schumacher, Y Shimada
Mechanical property tests such as the diametral tensile, uniaxial tensile, biaxial flexural, shear, and transverse strength tests are commonly used for assessing the bond that forms between dental composites and dental substrates such as dentin and enamel
Gale A. Holmes, E Feresenbet, E Pohl, Walter G. McDonough, D T. Raghavan, D Thompson
The development of methods to assess adhesion at the fiber-matrix interface in composite materials has been driven primarily by the recognition that the interface or interphase in many composite materials has a profound affect on the onset of failure in
Gale A. Holmes, Donald L. Hunston, Walter G. McDonough, R C. Peterson
One of the critical factors controlling the long-term performance and durability of composites in structural applications is the interfacial shear strength (IFSS). The single fiber composite (SFC) test has been viewed by many as the best test for
Walter G. McDonough, Joy P. Dunkers, Gale A. Holmes, Richard~undefined~undefined~undefined~undefined~undefined Parnas
The objective of our research was to extend the use of the single fiber fragmentation test to include fast reacting resin systems and to determine the effect of gelation time on interfacial shear properties. To do this work, we developed a processing
Joy Dunkers, C G. Zimba, Kathleen M. Flynn, Donald L. Hunston, R Prasankumar, X Li, J G. Fujimoto
Optical coherence tomography (OCT) is a non-destructive and non-contact technique that images microstructure within scattering media. In this work, the versatility of OCT for non-destructive evaluation is demonstrated through imaging of composite
Joy Dunkers, Richard~undefined~undefined~undefined~undefined~undefined Parnas, C G. Zimba, R C. Peterson, Kathleen M. Flynn, J G. Fujimoto, B E. Bouma
Optical coherence tomography (OCT) is a non-destructive and non-contact technique to image microstructure within scattering media. The application of OCT to highly scattering materials such as polymer composites is especially challenging. In this work, OCT