Zur Analyse von Eisen und-Stahl

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Physico-mechanical properties and biodegradation of oxo-degradable HDPE/PLA blends

Blends of high density polyethylene/poly(lactic acid) with/without compatibilizer and pro-oxidant (cobalt stearate) were prepared by melt blending technique. In ratio 80/20, the blend revealed a good combination of tensile properties and optimum poly(lactic acid) content. The improvement in mechanical properties of this blend was achieved by addition of 4 phr compatibilizer. Cobalt stearate (CoSt) was added to 80/20 blends in 0.1% and 0.2% (w/w) ratios. The obtained blends were characterized by DSC, SEM, FTIR spectroscopy, rheological study, etc. All the prepared blends were able to biodegrade in composting environment and the blend containing pro-oxidant was maximum degraded.     

Facile Synthesis of Furan-3,4-diacetates

A procedure for bis-cyclopropanation of furans with ethyl diazoacetate or methyl α-diazopropionate under dirhodium-tetraacetate catalysis is presented. Treatment of the products with ethanolic HCl furnished furan-3,4-diacetates.     

Synthesis, Structure, and Conformational Dynamics of Bridgehead-Substituted Nitrosamines. Di-1-adamantylnitrosamine and Di-1-norbornylnitrosamine

The synthesis of two bridgehead-substituted nitrosamines, di-1-adamantylnitrosamine (1) and di-1-norbornylnitrosamine (2), is described, and their solid state crystal structures are reported. Large bridgehead substituents increase the NNO angle of the nitrosamine (compared to that found for dimethylnitrosamine) without deconjugating the NNO pi system significantly. This structural change correlates with a red-shifted optical absorption, a diminished N,N rotational barrier, and a greater ease of oxidation of these hindered nitrosamines than is observed for dimethylnitrosamine. The electronic basis of these structure/function correlations is examined. It is concluded that 1 is more strained than N-nitroso-2,2,6,6-tetramethylpiperidine (3) which is more strained than 2 and that a raised (in energy) NO n orbital is primarily responsible for the extreme properties of the former.     

Synthesis of (±)-(E,E)-2,7-Dimethylocta-2,4-dienedioic Acid

(±-(2E,4E)-2,7-Dimethylocta-2,4-dienedioic acid ( 1 ) was synthesized efficiently from furan, employing a rhodium-carbenoid-induced furan-ring-unravelling reaction followed by an unusual NaBH₄/CeCl₃⋅7 H₂O reduction, Wittig-Horner olefination, and diester hydrolysis.     

Residence time distribution measurements in an ethyl acetate reactor using radiotracer technique

Journal of Radioanalytical and Nuclear Chemistry - In the present study, residence time distribution measurements were carried out in an industrial-scale ethyl acetate reactors using Bromine-82 as...