Materials Literature
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This paper describes the monomer types commonly used in making thermoplastic polyurethane elastomers. It gives chemical structure of the polymers and their general properties. Also de scribed are studies of the hydrolysis of thermoplastic polyurethane elastomers. This will include information on author's choice of hyd…
Abstract The crystallinity, elastic modulus, and tensile strength of samples of various draw ratios together with the true stress—strain curves of high‐density polyethylene were determined to establish correlations with morphological changes occurring during deformation. Changes of crystallinity at draw ratios below 5…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTSilicon-transition metal chemistry. I. Photochemical preparation of silyl(transition metal) hydridesWilliam A. G. Graham and W. JetzCite this: Inorg. Chem. 1971, 10, 1, 4–9Publication Date (Print):January 1, 1971Publication History Published online1 May 2002Published inissue…
The dielectric β relaxation of polyvinyl chloride has been studied in the ranges of temperature, pressure and frequency, 296 to 353 K, 1 × 105 to 3 × 108 N m–2 and 1 to 105 Hz. Detailed results are discussed in terms of current concepts of the α, β and (αβ) relaxations which occur in amorphous polymers and in small mo…
Abstract An NMR method for determining the distribution of acetyl groups in cellulose acetates was developed. Treatment of cellulose acetates with acetyl‐ d 3 chloride gave products having simple spectra which could be analyzed quantitatively to give the distribution of acetyl groups in the original sample. The method…
Experimental observations on thermal injury and death of bacteria in the stationary phase can be explained by assuming that death results from inactivation of (X(L)) of N critical sites. It is assumed: (i) that inactivation of individual sites occurs at random and follows first-order kinetics, (ii) that the critical s…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTInfrared studies of the disproportionation reaction of nitric oxide on Y-type zeolitesChien-Chung Chao and Jack H. LunsfordCite this: J. Am. Chem. Soc. 1971, 93, 1, 71–77Publication Date (Print):January 1, 1971Publication History Published online1 May 2002Published inissue 1…
An electron microscopic study was made of a uterine leiomyosarcoma, and this lesion was compared with normal myometrium and with uterine leiomyomas, one of which was of the cellular type. The leiomyomas had abundant myofilaments, well-developed pinocytic activity, a well-defined basement membrane, and an abundant extr…
The hydrolysis of the borohydride ion according to the equation (i) is catalysed by nickel–boron and cobalt–boron, BH4–+ 3H2O → H2BO3–+ 4H2(i) alloys. The metal-catalysed hydrolysis has been studied at 22·0 °C by measurement of the hydrogen gas evolved. Analysis of the gas evolved when the reaction is carried out in d…
Abstract
On analyse les propriétés de fluorescence de l'ion Bi3+ incorporé dans les oxydes et orthovanadates de terres rares LnVO4 (Ln = Sc, Y, Gd), La2O 3 et Ln2O3 (Ln = Sc, Lu, Y, Gd). Les transitions électroniques responsables de l'absorption et de l'émission sont attribuées aux niveaux de l'ion libre du premier état excité…
The total electrical conductivity and the electronic conductivity in silver beta alumina have been determined between 23° and 800°C over a wide range of oxygen partial pressure using a‐c and d‐c techniques. The ionic transference number was found to be very close to unity under all conditions. Comparison of these meas…
The stretching vibrations of water (H2O, HDO and D2O) in montmorillonite, hectorite, saponite and vermiculite are split into two components, similar to those seen in perchlorate solutions. Examination of lower hydrates and pyridine complexes of the layer silicates shows that the higher frequency component corresponds…
Spin-lattice (T1) and, where appropriate, tranverse (T2) relaxation times are reported for the protons in DMSO + water mixtures over a range of temperature and composition. Self-diffusion coefficients are also measured. A minimum in T1 for a d6-DMSO + H2O sample enables rotational correlation times for water molecules…
Abstract The stability of a capillary liquid bridge of given volume between two small, solid, equal, separated spheres is investigated by formulating and treating a minimum energy problem in the calculus of variations and by experiment. A conjecture is made that in the case of two solutions one and only one is minimiz…
A thermogravimetric system is described for the determination of the total oxygen consumption, sample weight‐change, and vaporization rate during the oxidation of . The results show an increasing deviation from parabolic kinetics with increasing temperature at 250 mm oxygen pressure. The following equation is used to…
The nature of oxygen adsorbed on slightly reduced TiO2 has been investigated using oxygen enriched with 17O2. On anatase, the oxygen adsorbs as O–2 with a hyperfine splitting Axx about g3 of 77 G; no structure could be resolved for Ayy and Azz. On rutile, oxygen adsorbs as O–2 on two sites of different thermal stabili…
There has been speculation in the past about the extent to which space charge formed by the flow of prebreakdown current affects the electric strength of polythene. In the present work, conduction and absorption-current measurements up to about half the breakdown field have given clear evidence of space-charge effects…
Interdiffusion in the aluminum-copper system was investigated in the temperature range of 400° to 535°C with diffusion couples of pure aluminum and copper metals.In the aluminum-copper equilibrium phase diagram there are five intermediate phases in this temperature range, namely γ2, δ, ζ2, η2 and θ. Electron probe mic…
A theory of orientation polarization in nematic liquid crystals is developed for a molecular dipole moment parallel to the long axis of the molecule. The theory is essentially an extension of the Debye model for normal polar liquids to take into account the strong intermolecular potential which is responsible for the…