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Showing 1 to 20 of 38 for “"wide-angle x-ray diffraction"”.
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Thermal and Morphological Study of Segmented Multiblock Copolyesters Containing 2,2,4,4-Tetramethyl-1,3-cyclobutanediol
… using differential scanning calorimetry, small angle X-ray scattering, wide angle X-ray diffraction and dynamic mechanical analysis. Molecular origins of the thermal transitions appearing in copolyesters were assigned by the copolyester analysis at different temperatures. The hard segments in …
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A Study of Crystallization in Bisphenol-A Polycarbonate
… by differential scanning calorimetry and wide-angle X-ray diffraction varied by over 6 hours because differential scanning calorimetry can detect a smaller amount of crystallinity than wide-angle X-ray diffraction. Signs of pre-ordering in the literature could be a result of experimental …
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Effect of Laser Induced Crystallinity Modification on Degradation and Drug Release of Biodegradable Polymer
… are examined using optical microscopy, wide-angle X-ray diffraction, and Fourier transform infrared spectroscopy. Solvent casting produces category 1 spherulites, and annealing the spin coated films leads to category 2 spherulites. Crystal structure of the two kinds of films shows …
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Improving the Exfoliation of Layered Silicate in a Poly(ethylene terephthalate) Matrix Using Supercritical Carbon Dioxide
… from a traditional melt compounding method. Wide angle x-ray diffraction (WAXD), mechanical testing and rheological analysis were used in order to characterize the silicate morphology, the composite mechanical properties and the relative amount of degradation between the various samples. …
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On the Melting and Crystallization of Linear Polyethylene, Poly(ethylene oxide) and Metallocene Linear Low-Density Polyethylene
… scanning calorimetry, optical microscopy, small angle X-ray scattering, and wide angle X-ray diffraction. In the case of linear polyethylene and poly(ethylene oxide), the zero-entropy production melting temperatures of initial lamellae of isothermally crystallized fractions were analyzed in the …
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The conserved C-terminal domain of spider tubuliform spidroin 1 contributes to extensibility in synthetic fibers
… but maintained constant toughness.</p> <p>Wide-angle X-ray diffraction studies indicate that post-drawn fibers containing the Cterminal domain of TuSp 1 have more amorphous content when compared to fibers lacking the C-terminus. Taken together, these studies demonstrate that recombinant …
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Manufacturing of Poly(vinylidene fluoride) and Evaluation of its Mechanical Properties
… a phase PVDF powder to b phase as measured with wide-angle x-ray diffraction. This is the first recorded instance of b phase powders forming from the a phase through ball milling. These b phase powders maintained their crystal structure during compression molding at 70°C.
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Evaluating the Time-Dependent Melting Behavior of Semicrystalline Polymers Through Strobl's 3-Phase Model
… differential scanning calorimetry (DSC), small angle X-ray scattering (SAXS), and wide angle X-ray diffraction. DSC experiments confirm the existence of a crystallization time-dependent low endotherm, and melting-recrystallization-remelting processes during heating. SAXS analysis using the …
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Fabrication and characterization of poly(amide-imides)/TiO₂ nanocomposite gas separation membranes
… in comparison to the unfilled poly(amide-imide). Wide Angle X- ray Diffraction (W AXD) study and Differential Scanning Calorimetry (DSC) analysis suggest that the Ti0₂ filled poly( amide-imide) have a lower crystallinity as compared to the unfilled poly(amide-imide). The dynamic mechanical …
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Effect of moderate magnetic annealing on the microstructure and mechanical behavior of a structural epoxy
… of the epoxy system where probed through wide-angle x-ray diffraction (WAXD) and texture analysis. Pole figures were generated for all the samples along the directions parallel and perpendicular to the applied magnetic field. This allowed, quantitatively, comparing the textures and fully …
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The mechanics of strain-induced crystallization in poly(ethylene terephthalate)
… large strain deformation was conducted over a wide range of strain rates (-0.005/s - 02.0/s) and temperatures (25 ° C - 105 ° C) and in both uniaxial and plane strain compression. The increase in crystallinity content with varying strain rate and temperature and for the two different states of …
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Gas transport properties of reverse selective nanocomposite materials
… depending on the nanoparticle concentration. Wide angle X-ray diffraction, nuclear magnetic resonance, and Fourier transform infra-red experiments were used to determine if the nanoparticles remained stable during film preparation. TiO₂ nanoparticles did not appear to react with water, the …
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Polyethylene-montmorillonite nanocomposites
… mixing device to provide elongational flow. Wide angle X-ray diffraction was used together with transmission electron microscopy to evaluate the particle dispersion, which consisted of intercalated clay organised in clusters up to one micron in diameter.<br/><br/>The performance of these …
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A Study of the Kinetics of Phase Separation in a Nickel-12.5 at.percent Silicon Alloy
… crystal has been studied by means of in situ wide-angle x-ray diffraction (XRD), small-angle neutron scattering (SANS) and high-resolution wide-angle XRD techniques. The kinetic parameters, i.e. rate constants, governing the growth of the particle size and the volume fraction of the …
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Synthesis and Characterization of Highly Functional Substituted Stilbene Copolymers and Semi-crystalline Poly(aryl ether sulfone)s
… of ¹³C labelled copolymer. The torsional angle of the H-13C-13C-H part of the anhydride ring was zero degrees, indicating an all cis configuration of the H-13C-13C-H moiety of the anhydride ring. Rod-coil block copolymers containing rigid polyampholyte blocks were designed and synthesized …
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Ethanol from photoperiod-sensitive sorghum: a study on biomass structure and process optimization
… including scanning electron microscopy and X-ray diffraction/scattering. Biomass at different botanic locations was investigated. Wide-angle X-ray diffraction (WAXD) study showed that the PS sorghum rind had oriented crystal peaks and the highest degree of crystallinity, whereas the …
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Solvent-Induced Crystallization of Poly(ether ether ketone)
… of crystallinity. From dynamic mass uptake and wide-angle x-ray diffraction (WAXD) results, it was found that the bulk sorption rate was equal to the bulk crystallization rate for all solvent systems that promoted SINC and PEEK exhibited diffusion-limited crystallization, irrespective of the …
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I, Crystallization and morphological studies of ICI's intermediate temperature semicrystalline (ITX) polymer and, II, The influence of deformation (shear strain) during bond formation on adhesive bond strength
… in material treated to less harsh conditions. Wide angle x-ray diffraction and the method of Hermans and Weidinger were utilized to calculate a theoretical heat of fusion of 180 J/g for ITX, and show that absolute crystallinity decreases by ~5% within the ICI recommended processing range. The …
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Crystallization and melting behavior of an aromatic semicrystalline polyimide, LaRC CPI-2
… crystalline polyimide known as LaRC CPI - 2 (Langley Research Center Crystalline rolyimide - second generation). This aromatic polyimide, a structural variant of the well known LaRC CPI, is synthesized froml 1,4-bis( 4-aminophenoxy-4' -benzoyl)benzene (1,4-BABB) and 4,4' -oxydiphthalic …
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