Materials Literature
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Abstract (Acetyl) (ethyl) cellulose (AEC) polymers with an ethyl degree of substitution (DS) of 2.5 and acetyl DS ranging from 0 to 0.5 dissolve readily in a wide range of organic solvents and form chiral nematic liquid crystalline phases in concentrated solution. The chiroptical properties of these liquid crystals ar…
Abstract A general method for the preparation of aromatic poly (ether‐sulfone‐amide)s has been developed. Polymerization is based on the palladium‐catalyzed polycondensation of aromatic dibromides containing ether sulfone structural units, aromatic diamines, and carbon monoxide. Reactions were carried out in N , N ‐di…
Abstract Highly active catalysts for copolymerization have been prepared by the precipitation of MgCl 2 /ToCl 4 complex with or without high surface area silica. Copolymerization of ethylene and 1‐butene has been tested by using the prepared catalysts at various concentrations of 1‐butene. The catalytic activities are…
Abstract Change in the glass transition temperature, T g , of poly(2,6‐dimethyl phenylene oxide), PPO, due to the dissolved CO 2 has been measured as a function of the gas pressure, p , using a high‐pressure DSC cell. At 61.2 atm, the highest pressure studied, T g is depressed by 31.6°C. The depression in T g is found…
Abstract The copolymerization of L , L ‐lactide and ε‐caprolactone was carried out using antimony trioxide and stannous octoate as catalysts. The effect of polymerization catalysts on the physical and the chemical microstructures of this copolymer was investigated by 13 C NMR and DSC analysis. Antimony trioxide causes…
Abstract Dielectric measurements were utilized to follow the advancement of cure in an epoxy/amine formulation. In contrast to earlier studies, complex impedance was measured during cure and used to calculate ionic resistivity. By using complex impedance were able to separate according to their frequency dependence th…
Abstract We have completely deconvoluted multiple ferroelectric‐to‐paraelectric phase transitions of a VDF/TrFE copolymer often observed on DSC by consecutive annealing below the Curie transition temperature and obtained three clear endothermic peaks resolved well from each other. We could also increase the Curie tran…
The mechanisms of nonradiative transitions in lanthanide ions in solutions are discussed. The results of the use of this phenomenon in the study of the structures and stability constants of complexes of lanthanide ions in solutions are described. The possible uses of the nonradiative energy transfer between lanthanide…
Abstract Vernon Ellis Cosslett was born on 16 June 1908 and died on 21 November 1990, after some months of an incapacitating illness. This brought to an end a memorable career in electron microscopy at Cambridge University. During this 42-year period the electron microscope has revolutionized our basic concepts in mat…
Abstract The effect of hydroxy and carboxylic acid substances on lactide polymerization in the presence of stannous octoate was investigated. A polymerization mechanism was postulated to attempt to explain the controversies existing in the literature and also to explain our experimental observations. Stannous alkoxide…
This work discusses techniques for developing new engineering materials such as elastomers, plastic blends, composites, ceramics and high-temperature alloys. Instrumentation for evaluating their properties and identifying potential end uses are presented.;The book is intended for materials, manufacturing, mechanical,…
Abstract The theoretical relationship between the shear modulus of a particulate reinforced composite and the viscosity of a solution with suspended particles was first proposed by Goodier. Since that time several partially successful attempts have been made in the literature to derive equations to describe the availa…
Superlattice structures, consisting of SrCuO2 and (Sr,Ca)CuO2 layers in the tetragonal, ‘‘infinite layer’’ crystal structure, have been grown by pulsed-laser deposition. Superlattice chemical modulation is observed for structures with SrCuO2 and (Sr,Ca)CuO2 layers as thin as a single unit cell (∼3.4 Å). X-ray diffract…
Abstract Poly(2,6‐dimethyl‐ p ‐phenylene) oxides (PPO) grafted with nylon 6 were prepared by first quantitatively brominating the PPO, followed by reacting the brominated products with nylon 6 of different molecular weights. The molecular weights of PPOs were kept intact during bromination. These graft copolymers with…
Abstract Simultaneous Interpenetrating Networks (SINs) were synthesized based on polyepichlorohydrin glycol (PECG), toluene diiocyanate (TDI), and trihydroxymethyl propane (TMP) as network I; and methyl methacrylate (MMA), ethyl methacrylate (EMA), methyl acrylate (MA), ethyl acrylate (EA), and ethyleneglycol dimethyl…
Polycrystalline diamond thin films have been formed on single crystal silicon field emitters using bias-enhanced nucleation in a microwave plasma chemical vapor deposition system. A diamond nucleation density greater than 1010/cm2 with small grain sizes (<25 nm) was achieved on the surfaces of silicon emitters…
Abstract Hydrothermal weathering of the peroxide vulcanized specimens of silicone rubber, EPDM rubber, and their 50 : 50 blend carried out for various durations at different temperatures reveals that silicone is very susceptible to degradation. For example, the modulus, the strength, and the elongation at break consis…
A novel technique combining electrospray and organometallic chemical vapor deposition (OMCVD) has been developed for the synthesis of new II–VI quantum dot composites. CdSe nanocrystals (quantum dots) of selected size are dispersed in a pyridine/acetonitrile mixture. The nanocrystals are transferred by electrospray in…
The difference in vibrational entropy between chemically disordered and $D{O}_{3}$-ordered ${\mathrm{Fe}}_{3}$Al was measured by calorimetry to be (0.10 \ifmmode\pm\else\textpm\fi{} 0.03) ${\mathit{k}}_{\mathit{B}}$/atom at high temperatures, with the ordered alloy having the lower vibrational entropy. Analysis of the…
Abstract Raw polymer and compound of hydrogenated acrylonitrile butadiene rubber (HNBR) were subjected to γ‐ray irradiation. Crosslinking was found to be the main chemical reaction induced by irradiation; the ratio of chain scission to crosslinking as well as the does at which gelation occurred were determined from ge…