Epoxy and polyurethane adhesive materials of elad,aquapol, and acrolat brands and their components

Different groups of chemical products developed and produced at the Macromer Scientific and Manufacturing Company are described and recommended for use in adhesive compositions, including reactive diluents for epoxy compositions, urethane prepolymers, binders for photocurable materials, aqueous polyurethane dispersions. The main characteristics of binders for glues are presented, as well as the prospects for their application in formulas of adhesive compositions.     

Thermomechanical and fractographic behavior of poly (HDDA‐co‐MMA): a study for its application in microcantilever sensors

Polymer‐based materials have drawn significant attention lately for their application in design and fabrication of thermomechanically stable highly sensitive three‐dimensional (3D) micromechanical sensor structures. Among these materials, 1,6 Hexane diol diacrylate (HDDA) has been extensively explored in laser‐based 3D microfabrication by microstereolithography. The thermomechanical properties of poly HDDA are important for their end use application in microcantilever‐based sensors. The present work explores the optimization of these properties by copolymerization of HDDA and methyl methacrylate (MMA) for these specific applications. The dynamic mechanical analysis, thermal expansion and mechanical studies were carried out for different compositions of poly (HDDA‐co‐MMA). An increase in MMA content in the copolymer matrix resulted in the enhancement of the thermomechanical stability. The variations of thermal expansion coefficient (CTE) for different compositions were also studied. Microhardness, uniaxial tensile, and flexural tests along with Poisson's ratio were determined to understand the mechanical properties of these compositions. The scanning electron micrographs of fractured surfaces of all the compositions were analyzed to understand the fracture mechanism of various compositions of this copolymer. Copyright © 2012 John Wiley & Sons, Ltd.     

Cluster kinetics model for mixtures of glassformers

For glassformers we propose a binary mixture relation for parameters in a cluster kinetics model previously shown to represent pure compound data for viscosity and dielectric relaxation as functions of either temperature or pressure. The model parameters are based on activation energies and activation volumes for cluster association-dissociation processes. With the mixture parameters, we calculated dielectric relaxation times and compared the results to experimental values for binary mixtures. Mixtures of sorbitol and glycerol (seven compositions), sorbitol and xylitol (three compositions), and polychloroepihydrin and polyvinylmethylether (three compositions) were studied.     

Limonene in Arizona liquid systems used in countercurrent chromatography. II Polarity and stationary-phase retention

The previous article in this series described the physico-chemical properties and chemical compositions of the two phases of the limonene–ethyl acetate–ethanol–water biphasic liquid system. This system was designed to be a “green” version of the so-called Arizona (AZ) scale of heptane–ethyl acetate–methanol compositions in which the heptane–ethyl acetate volume ratio is exactly the same as the methanol–water ratio. The first major difference between the standard and “green” AZ systems is the difference in upper and lower phase densities. The higher density of limonene compared with heptane greatly reduces the density difference of the “green” system: half the compositions have a density difference lower than 0.06 g mL^?1, precluding their use in hydrodynamic CCC columns. The other major difference is the phase polarity. The better distribution of ethanol between the upper organic and lower aqueous phases of the “green” AZ scale renders them more polar than their counterparts in standard heptane-based compositions. The test solutes aspirin and coumarin have higher distribution constants in the “green” AZ compositions. It is revealed that a hydrostatic column is suitable for use with all “green” compositions, with very good phase retention and limited driving pressure at high flow rates. A hydrodynamic column only functioned at limited flow rates with polar compositions of sufficient phase-density difference. The CCC chromatograms obtained with different compositions and columns are shown, and their peak position and sharpness discussed.     

A mass peak profile generation model to facilitate determination of elemental compositions of ions based on exact masses and isotopic abundances

To identify elemental compositions of ions, a mass peak profile generation model (PGM) was developed to plan data acquisitions and to interpret the data obtained by using a high resolution mass spectrometer (VG70-250SE). The PGM provides a list of all compositions possible for the exact mass of ion M and its error range from which the user selects a hypothetical composition. The PGM then plots [M + 1] and [M + 2] mass peak profiles and calculates masses and abundances of full and partial [M + 1] and [M + 2] profiles relative to the M profile. All possible compositions, calculated values for the exact masses and relative abundances, and measures of profile broadening and the shape of the [M + 2] profile are listed in a table. Pass-fail results for each of six criteria based on a comparison between table entries for the hypothetical composition and each of the other compositions are indicated. Compositions failing one or more criteria will be eliminated if the hypothetical composition is correct. The table provides assurance that all possible compositions based on the elements specified by the user have been considered. The PGM can be used to estimate the minimum resolution and number of determinations necessary to identify the correct composition by eliminating all others. As multiple determinations are made and error limits become smaller, average values are entered into the PGM to determine all compositions consistent with the data, often until only one composition remains.     

Utility of three types of mass spectrometers for determining elemental compositions of ions formed from chromatographically separated compounds

Concentration factors of 1000 and more reveal dozens of compounds in extracts of water supplies. Library mass spectra for most of these compounds are not available, and alternative means of identification are needed. Determination of the elemental compositions of the ions in mass spectra makes feasible searches of commercial and chemical literature that often lead to compound identification. Instrumental capabilities that constrain the utility of a mass spectrometer for determining ion compositions for compounds that elute from a chromatographic column are scan speed, mass accuracy, linear dynamic range, and resolving power. Mass peak profiling from selected ion recording data (MPPSIRD) performed with a double-focusing mass spectrometer provides the best combination of these capabilities. This technique provides unique ion compositions for ions of higher mass from compounds eluting from a gas chromatograph than can be obtained by orthogonal acceleration time-of-flight (oa-TOF) or Fourier transform ion cyclotron resonance mass spectrometry. Multiple compositions are usually possible for an ion with a mass exceeding 150 Da within the error limits of the mass measurement. The correct composition is selected based on measured exact masses of the mass peak profiles resulting from isotopic ions higher in mass by 1 and 2 Da and accurate measurement of the summed abundances of these isotopic ions relative to the monoisotopic ion. A profile generation model (PGM) automatically determines which compositions are consistent with measured exact masses and relative abundances. The utility of oa-TOF and double-focusing mass spectrometry using ion composition elucidation (MPPSIRD plus the PGM) are considered for determining ion compositions of two compounds found in drinking water extracts and a third compound from a monitoring well at a landfill. Published in 2002 by John Wiley & Sons, Ltd.     

Intermediate layers for laminated glazing materials

Laminated glazing is used in architecture, automotive, aviation, and other industries, where there is a demand for imparting to transparent constructions shatter-proof, impact-proof, bird- and bullet-proof, and certain special properties. The article describes organosilicon compositions for intermediate adhesives for triplexes. The compositions and properties of laminated glazing materials are presented.     

热致性共聚酯液晶的研究——以双酚-对苯二甲酸酯为间隔段

热致性共聚酯液晶由于具有优异的热、机械及加工等性能,引起人们对其应用及基础研究的重视。本实验室曾对以不同长度碳链为软间隔段的共聚酯进行了研究,在产物介晶单元含量不高(约20％)时即可表现出明显液晶性。本文选用以双酚A(BPA)或双酚S(BPS)-对苯二甲酸酯为间隔段进行了研究。     

Microscopy and FTIR investigations of the thermal gelation of methylcellulose in glycols

Methylcellulose is a well-known polymer due to its reverse thermal gel formation property in aqueous solutions. Support materials play an important role in the additive manufacturing of three dimensional parts using processes that utilise inkjet technology. This paper presents novel compositions of methylcellulose (MC) in non-aqueous solvents and investigates the thermal gel formation of these compositions. Compositions containing MC in different glycols (ethylene, propylene and butylene glycol) were prepared. Suitability of these compositions as reusable support materials for jetting based three dimensional printing processes have been previously established. In this paper, the mechanism of gelation of MC in three different glycols is explained and compared using experimental techniques such as heating and cooling between 25–150°C, hot stage microscopy and Fourier Transform Infrared (FTIR) spectroscopy. Based on the results, a generalised gel formation diagram for MC in glycols is presented and compared with aqueous MC gel formation. The results showed that MC forms gels in glycols upon cooling and the temperatures of gel formation/melting are different for each glycol. Understanding of the gel formation of these compositions can help in fine tuning these compositions for their performance during three dimensional printing.     

Isolation of niobium,tantalum, and titanium complex fluoride salts with alkali metal cations

Fluoride and oxofluoride salts of niobium, tantalum, and titanium were isolated. They precipitated from aqueous solutions and upon washing of organic extracts with aqueous solutions of ammonium, potassium, and sodium salts. The compositions of the isolated compounds were studied. Different compositions were established for the niobium salts that precipitated upon the dissolution of unwashed niobium hydroxide in hydrofluoric acid under the atmospheric pressure, in an autoclave, and upon addition of sodium, potassium, and ammonium salts to purely fluoride solutions of niobium, as well as for the tantalum ammonium and sodium salts isolated from aqueous and organic solutions. The data obtained can be used for the synthesis of niobium, tantalum, and titanium complex fluoride salts with various compositions.     

Lipids of cottonseed and palm oils and compositions based on them

The phsicochemical indices and the fatty-acid and triacylglycerol compositions of cottonseed and palm oils, of cottonseed oil hydrogenate, and of compositions based on them have been determined with the aid of IR and UV spectroscopies, GLC analysis, and chemical transformations. The compositions and amounts of the main classes of lipids in the initial oils and the hydrogenate have been studied. It has been found that in the process of hydrogenation the amount of oxygenated components falls. The work was conducted with the financial support of the Uzbek Fund for Fundamental Investigations.     

Determination of oligonucleotide composition from mass spectrometrically measured molecular weight

Extensive calculations for molecular mass versus subunit composition have been made for oligonucleotides from RNA and DNA to determine the extent to which base compositions might be derived from mass spectrometrically determined molecular weights. In the absence of compositional constraints (e.g., any numbers of A, U, G, C), measurement of molecular weight leads to only modest restrictions in allowable number of base compositions; however, if the compositional value for any one residue is known, such as from selective chemical modification or enzymatic cleavage, the number of allowable base compositions becomes unexpectedly low. For example, hydrolysis of RNA by ribonuclease T₁ produces oligonucleotides for which G=1, for which all base compositions can be uniquely specified up to the 14-mer level, solely by measurement of mass to within ±0,01%. The effects of methylation, phosphorylation state of nucleotide termini, and knowledge of chain length on the determination of subunit composition are discussed.     

Appication of ethylene-vinyl acetate copolymers as a polymeric base of concentrated pigments for coloring polyvinyl chloride plastics

Physico-mechanical characteristics of compositions of polyvinyl chloride with ethylene — vinyl acetate copolymer (PVC-EVAC) are investigated. The data obtained show that these components are well compatible in the region of high content in the composition of EVAC. This result allow to conclude that EVAC can be used for producing concentrated compositions with a pigment for coloring PVC insulation of electric cables.     

多嵌段聚醚氨酯薄膜的表面分析

本文用电子能谱(ESCA)角度外推法得到SPU最表层的组成,并与表面能测定等方法所得结果相对照,结果表明不同本体组成的SPU薄膜的表面成份大致相同。     

The electrical properties of schungite-containing compositions based on polypropylene and high-density polyethylene

Variations in the dc and ac conductivities of schungite-containing compositions based on polypropylene-high-density polyethylene (PP-PE) blends were studied depending on the composition of the polymeric blend, the volume concentration of the filler, and the order of the introduction of the composition components during the preparation of compositions. It was shown that the conductivities of the compositions could depend on the order of the introduction of the components. The structure of initial and schungite-containing PP-PE blends of different compositions was studied by atomic-force microscopy. It was shown that the structure of the compositions depended on the composition of the initial PP-PE blends and the order of the introduction of the components into schungite-filled PP-PE compositions.     

Modification of epoxy adhesives by hydroxyurethane components on the basis of renewable raw materials

A new class of modifiers for epoxy-amine adhesive and sealant compositions is proposed—carbonated epoxidized vegetable oils. Results of synthesis of the new modifier and properties of hybrid adhesive compositions using it are presented. Physical-mechanical properties were found to improve as a result of the introduction of hydroxyurethane components into the modified compositions.     

Characterization of rotameric mixtures in o- and m-substituted benzaldehydes by matrix isolation IR spectroscopy

The cis and trans conformers of benzaldehydes substituted in the o- or m-positions by Cl or CN can be differentiated by IR spectroscopy in Argon matrices. Partial photochemical rotamerization allows assignment of the IR bands and establishment of their relative intensities in pairs of rotamers, which permits, in turn, quantitation of equilibrium compositions prior to photolysis. The observed spectra and equilibrium compositions are in very good agreement with the predictions of vibrational spectra and free energy differences from B3LYP/6-31G calculations. The present work represents the first attempt to quantitate the small contributions that the cis rotamers make to the room-temperature equilibrium compositions of the two o-substituted benzaldehydes. The results for the m-substituted derivatives are compared to earlier estimates based on other methods.     

Phase composition of nanosized oxide film structures based on lanthanum and scandium doped HfO<Subscript>2</Subscript>

X-ray photoelectron spectroscopy, X-ray diffraction, and high-resolution transmission electron microscopy (over thickness profiling of the elemental and phase compositions of the samples) are used to investigate the elemental and phase compositions, structures, and microstructures of films synthesized in La–Hf–O and Sc–Hf–O systems from organometallic volatile compounds. The dependence of the phase compositions and microstructures of films on the concentration of a doping rare earth element is determined. It is found that lanthanum and scandium doping of hafnium oxide results in the formation of solid solutions of a hightemperature cubic modification. The conditions for obtaining the pyrochlore phase are determined in the nanocrystalline Hf–La–O system.     

Classification system for fullerenes

The universal classification of nanoshells developed on the basis of group theory makes it possible to formulate new rules of the composition and structure of fullerenes. The classification shows the possible numbers of atoms for a given point group of symmetry, their arrangement at the symmetry elements, the number of nonequivalent groups of atoms in a structure, their coordination numbers, and the angles between bonds. The suggested formulas of the compositions of nanostructures and their classification is valid for all fullerenes known thus far and makes it possible to determine the compositions of as yet unknown fullerenes. The composition of heteroatomic nanoparticles with differently coordinated atoms composed of several shells shifted with respect to one another in accordance with the lengths and angles of chemical bonds between atoms of these shells can also be determined. The suggested procedure was used for calculating bridging diatomic nanostructures, for which a general formula for determining the compositions is derived. The stability of some predicted structures is supported by accurate quantum-chemical calculations.     

New data on the chemistry of some of the rare elements

Summary New data are presented concerning the compositions and physicochemical properties of various compounds of some rare elements. The insoluble mixed ferrocyanides formed by various metals with lithium, rubidium, and cesium are reviewed, and new precipitating reagents for these elements are recommended. Regularities to be observed in changes in the compositions of mixed ferrocyanides of rare-earth metals are pointed out. Data are given on the compositions and stabilities of fluorides, oxalates, tartrates, and other compounds of gallium, indium, zirconium, and germanium.(Paper read at a session of the Division of Chemical Sciences of the Academy of Sciences of the USSR, October 31,1957)