Thermal,thermomechanical, and electrochemical characterization of the organic–inorganic hybrids poly(ethylene oxide) (PEO)–silica and PEO–silica–LiClO4

To study the effect of the silica content on the properties of the salt‐free and salt‐added hybrids based on poly(ethylene oxide) (PEO) and silica, two series of hybrids, PEO–silica and PEO–silica–LiClO₄ (O:Li, 9:1) hybrids were prepared via the in situ acid‐catalyzed sol–gel reactions of the precursors [i.e., PEO functionalized with triethoxysilane and tetraethyl orthosilicate (TEOS)]. The morphology of the hybrids was examined by scanning electron microscopy (SEM) of the fracture surfaces of the hybrid. The results indicated that the discontinuity develops with increasing the weight percent of silica in both hybrids. The differential scanning calorimetric (DSC) analysis indicated that effects of silica content on the glass transition temperatures (T_g) of the PEO phase were different in salt‐free and salt‐added hybrids. The T_g of PEO phase increased with increasing weight percent of silica in salt‐free hybrids, whereas the curve of T_g of PEO phase and silica content had a maximum at 35 wt % of silica content in salt‐added hybrids. For both salt‐free and salt‐added hybrids, peaks of the loss tangent, determined by dynamic mechanical analysis (DMA) were gradually broadened and lowered with increasing weight percent of silica. The storage modulus, E′, in the region above T_g increases with increasing silica content for both PEO–silica and PEO–silica–LiClO₄ hybrids. In the conductivity and composition curves for PEO–silica–LiClO₄ hybrids, the conductivity shows a maximum value of 3.7 × 10^?6 S/cm, corresponding to the sample with a 35 wt % of silica. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 81: 2471–2479, 2001     

New Intermediates and Dyes for Synthetic–polymer Fibres 4–(4–Methoxyanilino)–3–nitro–l, 8–naphthalimides

The synthesis of a series of 4–(4–methoxyanilinoj–3–nitro–1, 8–naphthalimides by condensation of amines with 4–(4–methoxyanilino)–3–nitronaphthalene–l, 8–dicarboxylic anhydride, and also by condensation of 4–halogeno–3–nitro–1, 8–naphthalimides with 4–methoxyaniline is described. They dye synthetic–polymer fibres, particularly polyesters, deep orange of excellent fastness properties. In presence of strong bases, e. g. 3–aminopropan–l–ol, the 4–arylamino group is replaced, giving a series of yellow dyes. A method is described for preparing the dyes without isolation of intermediate stages.     

4–Hydroxy–3–arylamino–l, 8–naphthalimides and 3–(and 4–) hydroxy–2–(and 5–) arylamino–7H–bcnzimidazo–(2, l–a)benz(d,e)isoquinolin–7–ones. Red dyes for synthetic–polymer fibres

4–Hydroxy–1, 8–naphthalimides and the isomer mixtures of'3–and 4–hydroxy–7 H–benzimidazo–(2, l–a)–benz(d, e)–isoquinolin–7–ones were coupled with diazotised arylamines to yield orange–red to bluish–red dyes having good coloration properties and excellent fastness to light on polyester fibres. Structure–property relationships in the dyes are discussed with respect to the nature of the substituents in the imide, imidazole and arylazo moieties.     

Fabrication and characterization of a solid polymeric electrolyte of PAN‐TiO2‐LiClO4

The ionic conductivity of PAN‐TiO₂‐LiClO₄ as a function of TiO₂ concentration and temperature has been reported. The electrolyte samples were prepared by solution casting technique. Their conductivity was measured using the impedance spectroscopy technique. The highest room temperature conductivity of 1.8 × 10^?4 S cm^?1 was obtained at 7.5 wt % of TiO₂ filler. It was observed that the relationship between temperature and conductivity were linear, fitting well in Arrhenius and not in Vogel‐Tamman‐Fulcher equation. The pre‐exponential factor, σ₀ and E_a are 1.8 × 10^?4 S cm^?1 and 0.15 eV, respectively. The conductivity data have been supported by differential scanning calorimeter (DSC) analysis. DSC analysis showed that there was a significant change in glass transition temperature (T_g) with the filler concentration. The SEM micrograph revealed that the TiO₂ particles are dispersed in the electrolyte, thus enhancing its conductivity. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2010     

Neuere Entwicklungen bei Härtbaren Formmassen. Werkstoffe – Anwendungen – Verarbeitungs-Technologien

New developments in thermosetting moulding compounds – Materials – Applications – Processing technology . Thermosetting moulding compounds are defined as raw materials manufacturing plastic parts under the influence of pressure and heat, mainly by compression, transfer and injection moulding which are formulated in workable form from thermosetting reactive resins, fillers, reinforcers, and other additives. The present article will consider only moulding compounds in granular form whose processing to moulded parts is mainly automated and which represent a group of plastics clearly distinct from pasty or liquid thermosetting moulding materials.     

TiCl4 and LiClO4 promoted Additions of O-Silylketene Acetals to Chiral β-Formyl Esters

Lewis acid promoted additions of O-silylketene acetals 1a and 1b to β-formyl ester 2 furnished γ-lactones 3a and 3b . Employing TiCl₄ as promotor chelate control leads to moderate or excellent trans selectivity, whereas LiClO4 as Lewis acid did not induce appreciable diastereoselectivity.     

Substituent Effects on the Colour,Dyeing and Fastness Properties of Trisubstituted 4–N–β–Hydroxyethyl–N–β–Cyanoethylaminoazobenzenes

School of Chemistry and Chemical Technology University of Bradford Bradford West Yorkshire BD7 1DP The synthesis of a series of 2′, 4′, 6′-trisubstituted derivatives of 4–N–β–hydroxyethyl–4– N–β–cyanoeth ylaminoazobenzene is reported, and the effect of the nature of the substituents on the colour, dyeing and fastness properties of these dyes is described. The dyes coloured synthetic–polymer fibres well, with the exception of those containing a methylsulphonyl group, which gave weaker dyeings on polyester. Dyes substituted by 2′-nitro groups tended to have poor light fastness, and reasons for the variations in the light fastness of monoazo dyes of this type are discussed.     

Thermodynamic Analysis on the Codeposition of SiC–Si3N4 Composite Ceramics by Chemical Vapor Deposition using SiCl4–NH3–CH4–H2–Ar Mixture Gases

A thermodynamic calculation on the chemical vapor deposition of the SiCl₄–NH₃–CH₄–H₂–Ar system was performed using the FactSage thermochemical software databases. Predominant condensed phases at equilibrium were SiC, Si₃N₄, graphite, and Si. The equilibrium conditions for the deposition of condensed phases in this system were determined as a function of the deposition temperature, dilution ratio (δ), and reactant ratios of CH₄/SiCl₄ and NH₃/SiCl₄. The CVD phase diagrams were used to understand the reactions occurring during the formation of Si–C–N from the gas species and determine the area of SiC–Si₃N₄. The concentration of condensed‐phase products was used to determine the deposition conditions of CVD SiC–Si₃N₄. The present work was helpful for further experimental investigation on CVD Si–C–N.     

Optimierungspotenzial von Wäschen zur Biogasaufbereitung. Teil 1 – Physikalische Wäschen

The number of biogas injection plants is increasing. In Germany, the requirements for biogas injection are specified by DVGW G 260 and G 262. The most applied biogas upgrading technologies are the pressure swing adsorption and physical as well as chemical scrubbers. However, these technologies are usually not adapted to the particular injection parameters of a specific location. In this work the influences of pressure, temperature and further parameters are shown for the water and the Genosorb scrubber. For the simulations the software Aspen Plus was applied, and measurements are used for verification.     

Styryl dyes – synthesis and applications during the last 15 years

One of the most widely used and important groups of functional dyes are the styryl dyes and a review of this functional dye class has not been published for more than 15 years. In this review article, we describe the new trends in the synthesis of a range of novel intermediates and styryl dyes and include the most interesting examples of their high‐tech applications. However, this review is not intended to be comprehensive because of the large number of styryl dye studies that have been carried out in this time. Styryl cyanine dyes are widely used in optical recording media in laser discs, as flexible dyes, laser dyes, as optical sensitisers and in various other fields, for example dye‐sensitised solar cells and dyes with non‐linear optical properties. Additionally, the most important applications for these dyes are in bio‐labelling and in medicinal analysis.     

Properties of Monoazo Disperse Dyes,Derivatives of 3– and 4–Aminophthalimide

The synthesis of several disperse dyes, from 3–amino–12–phthalimide and its N–methyl derivative as diazo component and N, N–dialky lanilines as coupling component is described. The dyeing behaviour and some physical properties of these dyes are investigated and compared with those of isomeric dyes containing azo groups in the 4–position, previously studied [5]. These properties were found to be considerably affected by the presence of an alkyl sub–stituent on the nitrogen atom of imide group. Further, dyes containing unsubstituted –NH groups showed somewhat better thermal properties (higher melting points and dyeings of better fastness to sublimation), but at the same time their dyeability was worse for all the known processes of dyeing polyester fibres. Based on the i. r. and visible spectra of the dyes under investigation, it was concluded that the dyes containing unsubstituted –NH groups are highly associated; dyes containing azo groups in the 4–position associate to give one product, whereas association of the dyes with azo groups in the 3–position leads to two different products.