Mechanical properties of polypropylene (PP) + high‐density polyethylene (HDPE) binary blends: Non‐isothermal degradation kinetics of PP + HDPE (80/20) Blends

In this study, the mechanical properties and non‐isothermal degradation kinetics of polypropylene (PP), high‐density polyethylene (HDPE) with dilauroyl peroxide and their blends in different mixture ratios were investigated. The effects of adding dilauroyl peroxide (0–0.20 wt%) on the mechanical and thermal properties of PP + HDPE blends have been studied. On the other hand, the kinetics of the thermal degradation and thermal oxidative degradation of PP + HDPE (80/20 wt%) blends were studied in different atmospheres, to analyze their thermal stability. The kinetic and thermodynamic parameters such as the activation energy, E_a, the pre‐exponential factor, A, the reaction order, n, the entropy change, the enthalpy change, and the free energies of activated complex related to PP, HDPE, and blend systems were calculated by means of the several methods on the basis of the single heating rate. A computer program was developed for automatically processing the data to estimate the reaction parameters by using different models. Most appropriate method was determined for each decomposition step according to the least‐squares linear regression. Copyright © 2013 John Wiley & Sons, Ltd.     

Design,Synthesis and Characterization of 3,4-Dihydro-2H-pyran Containing Copolymer/Clay Nanocomposites

We introduce briefly surface modification of clay minerals, structure, properties and, characterization techniques of polymer-clay (PCN's) nanocomposites. Organically modified layered-silicates or nanoclays have become an attractive class of hybrid materials due to their prospective use in a great variety of applications from industry to health. For design, synthesis and characterization for potential biomedical nanocomposites, antitumor-active copolymer; poly(DHP-alt-MA) were used to prepare copolymer/clay nanocomposites. The functional copolymers, having a combination of rigid/flexible linkages and an ability of complex-formation with interlayered surface of organo-silicate, and their nanocomposites have been synthesized by interlamellar complex-radical copolymerization of intercalated monomer complexes of maleic anhydride (MA) and 3,4-Dihydro-2H-pyran (DHP) with three alkyl ammonium salts surface modified bentonite and monomer mixtures. Poly(DHP-alt-MA) pristine copolymer and poly(DHP-alt-MA)/organically modified bentonite nanocomposites were characterized by Attenuated Total Reflectance-Fourier Transform Infrared Spectroscopy (ATR-FTIR), HR-Raman, X-ray diffraction (XRD) and TEM methods.     

Synthesis and Characterization of a New Dioxime and Its Heterotrinuclear BF2 + Capped Complexes

ω‐Isonitrosoacetophenone 1 Uçan, H. ? and Mirzao?lu, R. 1990. Synth. React. Inorg. Met.‐Org. Chem., 20: 437[Taylor & Francis Online], [Web of Science ®] , [Google Scholar], phenylglyoxime 2 Burakevich, J. V., Lore, A. M. and Volpp, G. P. 1971. J. Org. Chem., 36: 1[Crossref], [Web of Science ®] , [Google Scholar], chlorophenylglyoxime 1 Uçan, H. ? and Mirzao?lu, R. 1990. Synth. React. Inorg. Met.‐Org. Chem., 20: 437[Taylor & Francis Online], [Web of Science ®] , [Google Scholar], dopaminophenylglyoxime 3 Uysal, ?., Co?kun, A., Koç, Z. E., Uçan, M. and Uçan, H. ?. 2007. R. J. Coord. Chem., 33: 351–357. [Crossref] , [Google Scholar] and [(salen/saloph)Fe]₂O 4 Kopel, P., Sindelar, Z. and Klicka, R. 1998. Trans. Met. Chem., 23: 139[Web of Science ®] , [Google Scholar] have been synthesized as described in the literature procedure. [Fe(III)(salen/saloph)dopaminophenylglyoxime)] (starting complexes) have been synthesized from dopaminophenylglyoxime and tetradentate schiff bases which contain dinuclear Fe(III) oxygen‐bridges N,N′‐bis(salicylidene)ethylenediamine (salenH₂) and bis(salicylidene)‐o‐phenylenediamine (salophH₂). The new heterotrinuclear complexes have been obtained from starting complexes and Co(II), Ni(II), Cu(II) salts. Then, heterotrinuclear vic‐dioxime complexes containing BF₂ ⁺ capped have been synthesized. The complexes have been characterized as low‐spin distorted octahedral Fe(III) bridged by o‐hydroxyphenolic groups. The o‐hydroxyphenolic groups play a role as bridges for weak antiferromagnetic intramolecular exchange. The structure of dioxime and its complexes were identified by using elemental analysis, ICP‐AES, ¹H‐NMR and IR spectral data.     

Synthesis, characterization, and antimicrobial activity of a novel proton salt and its Cu(II) complex

A novel proton transfer compound (H₂Ppz)(HDipic)₂ (I) obtained from 2-(piperazin-1-yl)ethanol (Ppz) and pyridine-2,6-dicarboxylic acid (H₂Dipic) and its Cu(II) complex (H₂Ppz)[Cu(Dipic)₂] · 6H₂O (II) have been prepared and characterized by elemental, spectral (¹H and ¹³C NMR, IR and Uv-Vis) and thermal analyses. Magnetic measurement and single crystal X-ray diffraction methods have also been applied for compound II. The molecular structure of II consists of one 1-(2-hydroxyethyl)piperazine-1,4-diium cation, one bis(pyridinium-2,6-dicarboxylate)Cu(II) anion and six uncoordinated water molecules. In complex II, the copper ion coordinates to two oxygen and one nitrogen atoms of two pyridine-2,6-dicarboxylate molecules forming an octahedral conformation. Furthermore, the synthesised compounds (I and II) were screened for their antimicrobial activities against Gram (?) (Escherichia coli and Pseudomonas aeruginosa) and Gram (+) (Staphylococcusaureus and Bacillus cereus). The results were reported, discussed and compared with the corresponding starting materials (H₂Dipic and Ppz).     

Archaeometric study of possible Ninevite‐5 pottery from upper Tigris region using SEM‐EDS,PEDXRF, and OM

This study aims to reveal the production technology of some representative samples of possible Ninevite‐5 potsherds which are generally dated between the Early Jezirah I to EJ‐II/EJ‐III periods (roughly 3000–2500 bc ) and accepted as the typical ceramics reflecting the northern Mesopotamian culture in the first half of the 3rd millennium BC. The samples were selected from the archeological excavation area of Kuriki (upper Tigris region, Turkey) and exposed to multiple analytical techniques including scanning electron microscopy with an energy dispersive spectrometer, optical microscopy, and polarized energy dispersive X‐ray fluorescence spectrometry. The results showed that all the samples have high amounts of CaO (up to 29.83 wt.%) indicating use of calcareous clay deposits and they have an analogous chemical compositions in terms of both major oxides and trace elements which implied the use of the same raw materials. The vitrification degrees of the samples, examined by back scattered electron images, suggested that the firing temperature of the potsherds did not exceed the range of 800–900°C. It was also revealed that the firing atmosphere was oxidative which would be attributed to use of kiln firing rather than a bonfire or pit firing. Both the chemical and petrographic results suggested that the investigated samples presumably belong to a regional (upper Tigris) production rather than a local one.     

Graybody radiation phenomena in a fractional manner

In this paper, the graybody radiation phenomena has been handled with the help of fractional calculus. Fractional definition of graybody spectrum has been written in terms of Mittag‐Leffler function. The obtained data from fractional calculus approximation for nearly 2.87 × 10⁷ K have been compared with literature values and standard blackbody radiation.     

A photophysical study of the interactions in poly(styrene-4-sulphonate)–n-butylvinylether block and random copolymers

Interactions between the moieties responsible for the conformations and hydrophobic microdomains in poly(styrene-4-sulphonate) (PSS) and its copolymers with n-butylvinylether (BVE) were studied by their emission spectra and the lifetimes of the phenyl groups and pyrene used as a photochemical probe. The emission spectra of PSS shows bands due to dimers and higher aggregates as well as the characteristic excimer band. At low concentrations, the random copolymers have spectra similar to that of the free monomer, whereas the block copolymers have spectra like that of PSS. At higher concentrations, the random copolymer also shows these excimer bands, due to interchain interactions. Results from the emission of pyrene prove that the behaviour of the copolymers with approximately 40% BVE seems to be relatively independent of having random or block configurations. Except at low concentrations (<0.05 g/dl), where the block copolymer already has a conformation with “stable” hydrophobic microdomains, both types of copolymers behave similarly. There is an initial aggregate equilibrium between individual chains and aggregates, associated with a relocation of the probes. At higher concentrations, both copolymers suffer a severe change in conformation, due to the formation of “stable” hydrophobic microdomains, resulting from interchain interactions. In both cases the lifetimes of pyrene are of the order of 240 ± 10 ns. Received: 27 August 1998 Accepted: 11 January 1999     

Studies on the Thermal Decompositions of Heteropolynuclear Glyoxylates of Cr(III) and Cu(II)

Complexes of Cr(III):Cu(II) with the glyoxylate dianion as ligand were synthesized in the range of cation atomic ratios (0.01–8):1.0. The results of non-isothermal analysis of the synthesized compounds correlated with the results of IR and UV-VIS spectroscopy, and gas chromatography of the volatile products of the decomposition allowed the formulation of a mechanism for the decomposition of the complex with Cr(III):Cu(II)=2:1 and the assumption that the other complexes are mixtures of this with the homopolynuclear complexes of Cr(III) and Cu(II), depending on the ratio of the cations Cr(III):Cu(II). The thermal conversion of the complexes takes place at relatively low temperatures, with partial transformation of the ligand into oxalate and of the oxide mixture into CuCrO₄. This revised version was published online in August 2006 with corrections to the Cover Date.     

Development of a voltammetric method of analysis using praseodymium oxide-carbon nanotubes for the sensitive detection of dopamine in the presence of tramadol,paracetamol and ascorbic acid

A sensitive and selective method of analysis was constructed by the the combination of praseodymium oxide and carbon nanotubes. The charge transfer resistance (Rct) values of 109 in 1 × 10⁻³ M K₃[Fe(CN)₆] and 79 Ω in 5 × 10⁻⁶ M dopamine indicate that Pr₆O₁₁@MWCNTs/GCE enables an excellent electron pathway between electrolyte and electrode. The platform was successfully applied for the determination of dopamine in the presence of tramadol, paracetamol and ascorbic acid. The platform exhibited a remarkable decrease in ▵Ep for DA. A dynamic linear range from 1.2 × 10⁻⁹ M to 1.8 × 10⁻⁵ M was obtained with an LOD of 1.0 × 10⁻¹⁰ M. Such a sensitive and selective method of analysis makes Pr₆O₁₁@MWCNTs/GCE of high interest to observe trace level of DA with good accuracy and precision.     

Industrial cutting waste granite dust reinforced cardanol benzoxazine/epoxy resin hybrid composites for high-voltage electrical insulation applications

An attempt has been made to develop hybrid composites from benzoxazine monomer (C-ddm) hybridized with DGEBA epoxy resin (EP) and reinforced with varying weight percentages (20 wt%, 40 wt%, 60 wt%, 80 wt% and 100 wt%) of glycidoxypropyltrimethoxy- silane (GPTMS) functionalized granite dust (GD) obtained from industrial granite cutting and polishing process in order to utilize them for electrical insulation applications. The thermal stability of granite dust reinforced poly(EP-co-C-ddm) composites was studied by TGA analysis. Among the composites samples studied, 100 wt% GD reinforced poly(EP-co-C-ddm) composites possess better thermal stability than that of other neat matrices and composites. Among the composites prepared using varying weight percentages of functionalized GD reinforcement, it was observed that 80 wt% GD reinforced poly(EP-co-C-ddm) composites possesses better hydrophobic character than that of other neat matrices and composites. The value of LOI calculated for neat matrix (poly[EP-co-C-ddm]) and 20 wt%, 40 wt%, 60 wt%, 80 wt% and 100 wt% GD reinforced composites was found to be 22, 28, 34, 40, 43 and 45 respectively. The 80 wt% GD reinforced poly(EP-co-C-ddm) composites possess the higher values of tensile strength and flexural strength of 47 MPa and 140 MPa, respectively than those of their samples. The values of electrical surface resistivity and electrical volume resistivity of all the neat matrices and GD reinforced polybenzoxazine composites were found to be in the order of 10¹² and 10¹³ respectively. The values of dielectric strength obtained from break down voltage (BDV) for neat matrix [poly(EP-co-C-ddm)] and 20 wt%, 40 wt%, 60 wt%, 80 wt% and 100 wt% of GD reinforced poly(EP-co-C-ddm) composites are 15.0, 15.5, 16.5, 17.0, 17.0 and 17.0 kV/mm, respectively. Data obtained from thermal stability, hydrophobic behavior and dielectric studies it was inferred that the hybrid polymer composites developed in the present work can be conveniently used in the form insulators, sealants, adhesives and matrices where application demands at high-performance industrial and engineering applications.