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Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
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Showing 1 to 17 of 17 for “"WAXD"”.
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The mechanics of strain-induced crystallization in poly(ethylene terephthalate)
… was studied using Wide Angle X-ray Diffraction (WAXD) measurements. The results of the mechanical tests, DSC and WAXD measurements indicated that straininduced crystallization does not occur in uniaxial compression at temperatures below the glass transition, however, a shift in the cold …
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Ethanol from photoperiod-sensitive sorghum: a study on biomass structure and process optimization
… 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 crystalline structures of the inner pith and leaf were less ordered. The results from WAXD suggested that crystalline …
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Solvent-Induced Crystallization of Poly(ether ether ketone)
… 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 nature of the transport …
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Synthesis and Properties of Novel Triptycene-containing Segmented Polyurethanes and Semicrystalline Polysulfone-polyester Multiblock Copolymers
… by the analysis of wide-angle X-ray diffraction (WAXD) on the films strained to 370 %. Crystallizable PCT segments were copolymerized with PAESs to enhance solvent resistance and mechanical properties. PAES oligomers (Mn = 2000 g/mol) were first synthesized, and then reacted with dimethyl …
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Improving the Exfoliation of Layered Silicate in a Poly(ethylene terephthalate) Matrix Using Supercritical Carbon Dioxide
… 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. Results show that scCO2 processed …
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Preferential nanoreinforcement of thermoplastic polyurethane elastomers with dispersed nano-clay
… of a single hard-domain in block-polymeric TPU. WAXD, TEM, and AFM phase imaging of cast films following solvent exchange show that the nano-clay is well dispersed in the TPUs. Uniaxial mechanical testing showed that as much as a 23-fold increase in elastic modulus, 100% increase in toughness, …
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Effect of moderate magnetic annealing on the microstructure and mechanical behavior of a structural epoxy
… 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 understanding the mechanisms …
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The Effect of Nanoscale Particles and Ionomer Architecture on the Crystallization Behavior of Sulfonated Syndiotactic Polystyrene
… ionomer clay hybrids were studies via TEM and WAXD while the crystallization behavior of SsPS in the presence of the clay was evaluated using DSC. It was found that the SsPS matrix containing 5 wt.% organically-modified clay crystallized more rapidly than the sPS homopolymer containing the same …
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Hexagonally-Packed Helical Oligo(m-Phenylene Ethynylene) Nanotubules via Structural Modification and Guest Templation
… evaporation sample preparation technique, WAXD, and SAXD. The observation of chain length dependent and independent long spacings for these two series, respectively, fits the two models of lamellae and hexagonally-packed helices. An alternative route to the hexagonal phase, through …
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Process for Improving the Exfoliation and Dispersion of Nanoclay Particles into Polymer Matrices Using Supercritical Carbon Dioxide
… using conventional melt compounding techniques. WAXD and TEM data showed a good degree of exfoliation for clay concentrations as high as 6.8 wt% when the clay was expanded and mixed with CO₂. At this concentration, mechanical properties such as yield strength and modulus increased by as much as …
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Advancing Step-Growth Polymers: Novel Macromolecular Design and Electrostatic Interactions in Polyesters and Polyurethanes
… (SAXS), and wide-angle X-ray diffraction (WAXD) supported microphase separated morphologies in the trialkylphosphonium polyurethanes, despite the presence of ionic interactions. Sorption isotherm experiments revealed TBP polyurethanes displayed similar water sorption profiles to the …
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Synthesis and Characterization of trans-1,4-Cyclohexylene Ring Containing Poly(arylene ether sulfone)s
… (DSC) and wide angle X-ray diffraction (WAXD). A mechanical property study of the high molecular weight trans-1,4-cyclohexylene containing polymer samples showed moderate ultimate elongation enhancements. A series of PAES-polyester multiblock copolymers were synthesized with both solution …
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Supercritical Carbon Dioxide Processing Of Nano - Clays And Polymer/clay Nanocomposites
… by the absence of the diffraction peak in WAXD and the presence of individual tactoids that lost their parallel registry. The expanded flexible structure of the scCO2 processed clay exposes more of the available surface area allowing for more contact between the polymer and clay surface, …
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The Manufacture of Polymer Nanocomposite Materials Using Supercritical Carbon Dioxide
… (TEM) and wide angle X-ray diffraction (WAXD) results show that this modified procedure help to reduce the clay collapse when processing the composites with high clay loadings. Surface modified montmorillonite (MMT) nano-clay/polypropylene (PP) composite at 10 wt % nano-clay with improved …
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Non-covalent Intermolecular Interactions in Polymer Design: Segmented Copolymers to Non-viral Gene Delivery Vectors
… compared to PDMS-U controls and DSC and WAXD verified the amorphous character of PDMS-UOx. Oxamide incorporation showed a profound effect on the physical properties of PDMS-UOx copolymers compared to the controls and demonstrated promise for potential commercial applications. Two novel …
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Accelerated Testing Method to Estimate the Lifetime of Polyethylene Pipes
The ability to quickly develop predictions of the time-to-failure under different loading levels allows designers to choose the best polymeric material for a specific application. Additionally, it helps material producers to design, manufacture, test, and modify a polymeric material more rapidly. …