Search results for "Butadiene"
showing 6 items of 106 documents
Softening of Silica Filled Styrene-Butadiene Rubber under Uniaxial Cyclic Loading
2016
Stress-strain behaviour of silica filled styrene-butadiene rubber showed strong hysteresis and cyclic softening, while these effects were almost negligible for the neat rubber. Significant Mullins effect occurs between the first and second loading cycles, whereupon samples reach their steady state after four repeated cycles. The degree of softening increases with volume content of silica characterizing the softening effect as a breakdown of the filler-formed microstructure defined by both, specific interactions in the filler associations and between the filler and rubber matrix. Contribution of different damage mechanisms to the total energy losses on different stages of extension was estim…
Determination of metal concentrations in certified plastic reference materials after small-size autoclave and microwave-assisted digestion followed w…
2017
Abstract The digestion methods for the determination of As, Cd, Cr, Pb, Sb, Sn and Zn concentrations in plastic samples using microwave-assisted digestion (MW-AD) and small-size autoclave digestion was developed. The certified polyethylene, polypropylene, polyvinyl chloride and acrylonitrile butadiene styrene certified reference materials were used in order to find digestion method working properly for several sample matrices. Efficiency of the digestion methods was evaluated by analyzing the residual carbon in digests by TOC analyzer. MW-AD using a mixture of 7 mL of HNO 3 and 3 mL of H 2 O 2 as a digestion solution resulted in excellent recoveries for As, Cd, Pb, Sb and Zn, and were in th…
First Ruthenium Complex of Glyoxalbis(N-phenyl)osazone (LNHPhH2): Synthesis, X-ray Structure, Spectra, and Density Functional Theory Calculations of …
2007
The first ruthenium complex containing the parent osazone ligand, glyoxalbis(N-phenyl)osazone (LNHPhH2), is reported. The complex (LNHPhH2)Ru(PPh3)2Cl2 (1) was characterized with mass, IR, 1H NMR, and UV−vis spectroscopy as well as with theoretical calculations. Density functional theory calculations on the model compound (LNHPhH2)Ru(PMe3)2Cl2 (2) reproduce the geometrical features observed for 1 and verify that it formally contains a ruthenium(II) metal center coordinated by a neutral osazone. Subsequent bonding analyses identify π-interactions between the occupied orbitals of the metal fragment and the LUMO of the osazone, which results in transfer of approximately 0.3 electrons from the …
Theoretical investigation of paramagnetic group 13 diazabutadiene radicals: insights into the prediction and interpretation of EPR spectroscopy param…
2006
The electronic structures and the spin density distributions of the group 13 1,4-diaza(1,3)butadiene (DAB) radicals [(R-DAB)2M]˙, [(R-DAB)MX2]˙ and {[(R-DAB)MX]2}˙˙ (M = Al, Ga, In; X = F, Cl, Br, I; R = H, Me, tBu, Ph) are studied using density functional theory at both non-relativistic and relativistic levels of theory. The calculations demonstrate that all systems share a qualitatively similar electronic structure and are primarily ligand centred π-radicals. The calculated metal, nitrogen and hydrogen hyperfine couplings are found to be independent of the identity of the R-group and the halogen atom. They are, however, dependent on the geometry and oxidation state of the metal centre. Bo…
Theoretical Investigation of Paramagnetic Diazabutadiene Gallium(III)−Pnictogen Complexes: Insights into the Interpretation and Simulation of Electro…
2005
The electronic structures and the spin density distributions of the paramagnetic gallium 1,4-diaza(1,3)butadiene (DAB) model systems {(tBu-DAB)Ga(I)[Pn(SiH3)2]}• and the related dipnictogen species {(tBu-DAB)Ga[Pn(SiH3)2]2}• (Pn = N, P, As) were studied using density functional theory. The calculations demonstrate that all systems share a qualitatively similar electronic structure and are primarily ligand-centered π-radicals. The calculated electron paramagnetic resonance (EPR) hyperfine coupling constants (HFCCs) for these model systems were optimized using iterative methods and were used to create accurate spectral simulations of the parent radicals {(tBu-DAB)Ga(I)[Pn(SiMe3)2]}• (Pn = N, …
On the modification of the nitrile groups of acrylonitrile/butadiene/styrene into oxazoline in the melt
2000
Oxazoline functionality is well known to be highly reactive toward a lot of other functional groups like carboxyls, hydroxyls, mercaptans, and amines. In this work we report the possibility to modify the nitrile groups of an acrylonitrile/butadiene/styrene (ABS) copolymer into oxazoline in the molten state in the presence of aminoethanol as modifier agent and zinc acetate as a catalyst. The reaction has been carried out in a batch mixer and in a corotating twin screw extruder. The conversion of the nitrile groups into oxazoline has been verified by infrared spectroscopy, NMR analysis microanalysis and confirmed by thermomechanical characterization. The results indicate that the kinetic of g…