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[en] Copolymers of ethylene and propylene (PP) have a wide range of application in medical disposables, such as syringes, catheters and dialysis units. During radiation sterilization, formation of radiolysis products may cause yellowness, and loss of mechanical properties due to damages in chemical structures. We have recently reported a study of radical formation at low radiation doses and 77K and rheology of the high-energy radiolysis in a commercial PE/PP copolymer, Elpro. The co-polymer is comprised principally of PP and has only small ethylene content, ∼1 %. In the present report, in order to assess further the role of the stabilizer, we have studied the effect of mobilizer dioctylpthalate (DOP) by FTIR, XPS, and retention in mechanical properties by Instron's mechanical testing method for semicrystalline PE/PP copolymer. The FTIR spectra of Elpro and Elpro+Ca exhibited characteristic absorption bands of -C-H and -C-C of PP/PE. The spectra of the samples containing DOP were similar to those for Elpro but with additional charctaristic ester peaks, including carbonyl peak at 1735-1740 cm-1. When the co-polymer was irradiated with 25 kGy or 50 kGy at room temperature, the carbonyl peak was lost for samples having 0.5 phr of DOP probably due to chemical removal with out-gassing of volatile products. However, at higher concentrations of DOP, shifting of ester peak at 1735 cm-1 to 1719 cm-1 reflects chemical change at surface, most probably due to conversion of ester to aldehyde. C. Albano has reported the simultaneous presence of different degradation products, the band attributed to C=O group appears broader with an increase in radiation dose in various polyethylenes. XPS studies showed the presence of O 1s on the surface in presence of mobilizer, but decrease in intensity of O 1s relative to un-irradiated samples. At lower dose (25 kGy), 40-70 % of Eb retention was observed with no significant loss in T.S, but at 50 kGy mechanical properties could not be retained
[en] Knoevenagel condensation reaction of ethylene glycol-based aromatic aldehyde with malononitrile leads to the corresponding benzylidenemalononitrile derivatives which contain high yields of ethylene ether spacers. The product structures were derived from their IR, 1H-NMR, and 13C-NMR spectroscopy. Some of these compounds have been found to possess antibacterial activity.
[en] Experimental data on the thermal conductivity coefficient and viscosity coefficient of nanodiamond nanofluids are presented. Distilled water and ethylene glycol were used as the base fluid. Dependences of transport coefficients on concentration are obtained. It was shown that the thermal conductivity coefficient increases with increasing nanodiamonds concentration. It was shown that base fluids properties and nanodiamonds concentration affect on the rheology of nanofluids. (paper)
[en] Highlights: • The exchange interaction J and the first hyperpolarizability β for DAEs were calculated. • The direction of change is always logically related to the π-conjugation pathway. • The switching directions of J and β are different for some DAEs. • The SE values of β are smaller than the SE values of J for all molecules. • Oxidizing the sulfur atoms of the DAEs yields small variations on SE of J and β. We have calculated the exchange interaction J and the first hyperpolarizability β for photochromic diarylethenes (DAEs), 5,5′-diphenyl-di(3-thienyl)ethene 1, 5,5′-diphenyl-di(2-thienyl)ethene 2, 2,5-diphenyl-di(3-thienyl)ethene 3, and their corresponding oxidized derivatives. The switching direction of DAE 2 is found to be opposite from DAE 1. The switching direction of DAE 3 is opposite from DAE 1 for J, but not for β. For all molecules, the switching efficiency (SE) values of β are smaller than those of J. Oxidizing the sulfur atoms yields rather small variations on SEs of J and β. The non-trivial structure-property relationships for J and β are rationalized.
[en] Full text: There have been suggested various hypothesis of phasesous scheme for the mechanism of going the selective hydrogenation ethane-ethylene fraction (EEF) of paralysis gas. According to each hypothesis kinetic models have been elaborated. In order to define the parameters of kinetic models there was used industrial information. It has been found that the model, constructed on the 2-centres mechanism described the industrial processes the most exactly. The adequacy of this model has been proved
[en] Polyethylenimine (PEI) interlayer rinsing with different solvents for inverted organic light emitting diodes (OLEDs) is systematically studied in this paper. In comparison with the pristine one, the maximum current efficiency ( CE max) and power efficiency ( PE max) are enhanced by 21% and 22% for the device rinsing by ethylene glycol monomethyl ether (EEA). Little effect is found on the work function of the PEI interlayer rinsed by deionized water (DI), ethanol (EtOH), and EEA. On the other hand, the surface morphologies of PEI through different solvent treatments are quite different. Our results indicates that the surface morphology is the key to improving the device performance for IOLED as the work function of PEI keeps stable. (paper)
[en] Dislocation-pair-unbinding models suggesting that 2D melting is inherently a continuous transition have gained support from recent studies of the disordering of 2D Coulomb lattices such as those formed by charged microspheres in water and electrons above liquid helium surfaces. But, for reasons that are entirely clear, they appear less successful when applied to adsorbed phases. Heat capacity measurements show most adsorbed 2D solid melting transitions to be discontinuous like their 3D counterparts. Of the many systems explored to date, only one, ethylene-on-graphite, has been found to have a heat capacity signature suggestive of continuous melting. In attempting to understand what sets this system apart from the others, we have made a series of elastic and quasi-elastic neutron scattering investigations of submonolayer ethylene films on graphite and compared our results with data in the literature for an equivalent system, methane-on-graphite, in which melting is known (from heat capacity measurements) to be a discontinuous transition
[en] This book indicates petrochemistry with summary, importance and economic consideration of organic chemistry industry, synthetic gas ; ammonia, urea, nitric acid, oxo chemicals, phosgene, formic acid and neo-acids, methane ; hydrogen cyanide, HCN and chlorinated methanes, acetylene ; vinyl acetate, neoprene, acrylates and Reppe chemicals, ethylene ; polyethylene and ethanol, propylene ; allyl chloride and isoprene, hydrocarbon: butadiene, isobutylene, aromatic hydrocarbon and other petrochemistry productions.