Materials Literature
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The crystal structures of a series of dithiadiazolyl free radicals, p-XC6F4CNSSN (X˭F,Cl,Br and CN) are described in terms of dipolar interactions which induce chain-like motifs in the solid state. When X˭CN two morphologies are observed; the β-phase is polar and undergoes a phase transition to a weakly ferromagnetic…
Poly(propylene)/aromatic polyamide blends were prepared by melt mixing, without or with the addition of an interfacial modifier, viz. a poly(propylene) polymer grafted with 1 wt.-% of maleic anhydride. The characteristics of these polymer blends were investigated by differential scanning calorimetry, dynamic mechanica…
The Lifshitz–van der Waals theory has been used to calculate the contact angles of dispersive liquids and solids: diiodomethane, α-bromonaphtalene, methylnaphtalene, benzene, and n-octane, liquids on polytetrafluoroethylene, polystyrene, polyisobutene, polyvinylchloride, and polyethylene. The theoretical calculation o…
Different methods for characterizing the morphology of multiphase blends were applied to a blend of thermoplastic polyurethane with 20 wt% polypropylene as the dispersed phase. Optical microscopy, scanning electron microscopy (SEM), transmission electron microscopy (TEM), atomic force microscopy (AFM), and light scatt…
In applications like space satellites, high-energy physics experiments, and nuclear power stations, epoxy structural adhesives are normally used in an ionizing radiation environment. To check the effects of γ-irradiation on room temperature epoxy adhesives, mechanical measurements were undertaken for three different r…
The stress-strain behaviour of polyethylene, determined from mechanical tests at constant true strain rate, is characterized by high strain hardening in uniaxial tension and strain softening in simple shear. The strong influence of the deformation path is correlated with the different crystalline textures developed. T…
The microstructure of Al-Zn alloys, with the Zn atom fraction, x(Zn) less than or equal to 62%, has been studied in detail by XRD in dependence on the composition, temperature and previous thermal treatment. Precipitation phenomena in alloys, transferred to the supersaturated state by rapid quenching from the solid so…
During the oxidation of zircaloy fuel cladding, large stresses develop in the oxide layer, due to the volumetric expansion related to phase change. The present paper deals with intermediate temperatures, typically 300-450°C. (1) The first section of the paper shows that the local geometry of interface must be taken in…
For improved understnding of the transport of low-molecular substances' in moderately hydrophobic polymers, the temperature dependence of water vapor sorption and diffusion in poly-(3-hydroxybutyrate) (PHB) was studied for the first time. Equilibrium sorption and diffusion kinetics were determined by a quartz McBain's…
The surface properties of two block copolyurethanes based on 1,2-ethylene bis(4-phenyl isocyanate) (P2PDI), poly(tetramethylene ether glycol) (PTMG) or poly(propylene glycol) (PPG), and ethylene diamine, were investigated by attenuated total reflectance (ATR) infrared spectroscopy and X-ray photoelectron spectroscopy…
The compatibilization of mixtures of polyolefins or of polyolefins with polystyrene using either liquid polybutadiene (l-PB)/organic peroxide or styrene-butadiene-styrene (SBS) block copolymers was investigated. Tensile impact strength was chosen as a measure of compatibility. Binary blends LDPE/high-impact polystyren…
Abstract The linear character of transesterified deproteinized natural rubber (DPNR-TE) was confirmed by the analysis of terminal groups with NMR and viscometric analyses. The branch content of DPNR rubber from fresh latex was found to range from 0.3 to 1.3 and 0.7 to 3.2, based on tri- and tetra-functionalities, resp…
The enzyme catalase (H(2)O(2)-H(2)O(2) oxidoredutase; E.C. 11.1.6) was purified from haemolysate of human placenta and crystallized using the vapour-diffusion technique. Synchrotron-radiation diffraction data have been collected to 1.76 A resolution. The enzyme crystallized in the space group P2(1)2(1)2(1), with unit-…
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Composites of BaFe 12 O 19 particles dispersed throughout a 3‐mol%‐yttria‐doped zirconia (3Y‐TZP) matrix have been prepared using the pressureless reactive sintering of 3Y‐TZP, BaCO 3 , and γ‐Fe 2 O 3 powders. The reaction behavior of the mixed powder was studied with an in situ , high‐temperature powder X‐ray diffrac…
Failure mechanisms in polymer composites were investigated with the method of ultra-small-angle X-ray scattering using synchrotron radiation and acoustic emission analysis simultaneously. The composites were prepared from polystyrene filled with glass beads with different coatings. The two-dimensional scattering patte…
The addition of oxygen in Ca0.5Sr0.5Ga2S4:Ce phosphor was found to nearly double the luminance and to blue shift the emission spectrum of the Ce+3 4f–5d transition. X-ray photoelectron spectroscopy (XPS) analysis was used to investigate the local chemistry of the Ce+3 luminescent center in the undoped and oxygen-doped…
Passivation of the zirconium surface and stability of anodic oxide film were investigated as a function of surface preparation. The mechanically polished surface appeared to be more reactive toward oxide thickening than the etched one, as revealed by impedance measurements. Oxide film formed on the etched electrode di…
We consider the effects of the application of electric and magnetic fields to a homogeneously aligned nematic liquid crystal which lies between parallel plates. The average alignment of the fluid molecules is known as the director and it is set parallel to the top and bottom bounding surfaces. At a critical field stre…
The low-temperature form of K3Sm(PO4)2 crystallizes in the monoclinic system [a = 7.4347(5) Å, b = 5.6270(5) Å, c = 9.4919(5) Å, β = 90.870(6)°, Z = 2, space group P21/m]. The structure has been determined using 1263 independent reflections (R = 0.045, Rw = 0.11) and is found to be of the glaserite type. The Raman and…